MONONUCLEAR LEUKOCYTE DIRECTED ENDOTHELIAL ADHESION MOLECULE ASSOCIATED WITH ATHEROSCLEROSIS

Abstract: The invention relates to novel endothelial cell-leukocyte adhesion molecules designated ATHERO-ELAM. ATHERO-ELAM molecules are expressed on cultured endothelial cells stimulated with bacterial LPS and selectively mediate the binding of monocytes to the endothelial cells. Monoclonal antibodies specific for ATHERO-ELAM bind to vascular endothelial cells involved in early atherosclerotic lesions, but not to vascular endothelial cells from uninvolved arterial tissue. ATHERO-ELAM and antibodies directed to ATHERO-ELAM may be used in identifying early atherosclerotic lesions and in treating and preventing atherosclerosis.

Description: MONONUCLEAR LEUKOCYTE DIRECTED ENDOTHELIAL ADHESION MOLξCULE ASSOCIATED WITH ATHEROSCLEROSIS Cross Reference to Related Application This Application is a Continuation-In-Part of U.S. Application Serial No. 07/487,038, filed March 2, 1990. FIELD OF THE INVENTION This invention relates to endothelial cell proteins involved in ononuclear leukocyte adherence to endothelial cells and their role in the development of atherosclerotic lesions in mammals. BACKGROUND OF THE INVENTION The endothelial lining of blood vessels normally plays a critical role in maintaining ho eostasis at the vessel wall- blood interface (Gimbrone, M.A., Jr., in Vascular Endothelium in Hemostasis and Thrombosis, Ed. Churchill Livingston, Edinburgh, p. 1 (1986); Gryglewski, R.J. et al ., Hypertension 12:530 (1988)). However, changes to the endothelial lining have been implicated in development of atherosclerotic lesions. Ultrastructural and immunohistochemical studies in various animal models and human tissues have established that the adherence of blood monocytes to endothelial cells (EC) lining large arteries is one of the earliest detectable events in atherosclerosis (Gerrity, R.G. et al . , Am. J. Pathol . 95:775 (1979); Gerrity, R.G., Am. J. Pathol . 103:181 (1981); Gerrity, R.G., Am. J. Pathol. 103:191 (1981); Joris, I. et al.. Am. J. Pathol. U3:341 (1983); Klurfeld, D.M., Arch. Pathol. Lab. Med. 109:445 (1985); Schaffner, T. et al . , Am. J. Pathol . 100:57 (1980); Gown, A.M. et al . , Am. J. Pathol. 125:191 (1986); Faggiotto, A. et al ., Arteriosclerosis 4:323 (1984); Faggiotto, A. et al . - Arteriosclerosis 4:341 (1984); Fowler, S. et al.- Lab. Invest. 41:372 (1979); Watanabe, T. et al.. Lab Invest. 53:80 (1985); Walker, L.N. et al . - Am. J. Pathol . 125:450 (1986); Schwartz, C.J. et al . , Virchows Arch. (Path. Anat.) 405:175 (1985); Lewis, C.J. et al . , Ann. NY Acad. Sci. 454:91 (1985)). The subsequent transendothelial migration of monocytes, their accumulation in the intima and development into lipid-engorged "foam cells", appear to be important steps in the initiation of atherosclerotic lesions (Ross, R., N. Enα. J. Med. 314:488 (1986); Davies, P.F., Lab. Invest. 55:5 (1986); Munro, J.M. et al ., Lab. Invest. 58:249 (1988)). Monocytes and macrophage foam cells may also contribute to the progression of atherosclerotic lesions by producing cytokines and growth factors (Libby, P., Molecular Aspects of Medicine 96:499 (1987)). These in turn may amplify recruit¬ ment, induce migration of smooth muscle cells into the intima (Ross, R., N. Enα. J. Med. 314:488 (1986)), stimulate cell replication (Libby, P. et al .. New Enα. J. Med. 318:1493 (1988)), and modify the immunologic state of lesions through lymphocyte recruitment and induction of Class II MHC antigens (Hansson, G.K. et al . , Arteriosclerosis 9:567 (1989)). The initial step in leukocyte migration, whether in atherosclerosis or in inflammation, is the adherence of a circulating leukocyte to the endothelial lining. In athero¬ sclerosis, the migration of monocytes into the arterial intima and the resulting formation or expansion of athero¬ sclerotic lesions, is a localized phenomenon (Gerrity, R.G. et al.. Am. J. Pathol. 95:775 (1979); Gerrity, R.G., Am. J. Pathol. 103:181 (1981); Gerrity, R.G., Am. J. Pathol. 103:191 (1981); Joris, I. et al . , Am. J. Pathol. 113:341 (1983); Klurfeld, D.M., Arch. Pathol. Lab. Med. 109:445 (1985); Schaffner, T. et al.. Am. J. Pathol. 100:57 (1980); Gown, A.M. et al.. Am. J. Pathol. 125:191 (1986); Faggiotto, A. et al .. Arteriosclerosis 4:323 (1984); Faggiotto, A. et al .. Arterio¬ sclerosis 4:341 (1984); Fowler, S. et al .. Lab. Invest. 41:372 (1979); Watanabe, T. et al . , Lab Invest. 53:80 (1985); Walker, L.N. et al.. Am. J. Pathol. 125:450 (1986); Schwartz, C.J. et al.. Virchows Arch. (Path. Anat.) 405:175 (1985); Lewis, C.J. et al.. Ann. NY Acad. Sci. 454:91 (1985); Ross, R., N. Enα. J. Med. 314:488 (1986); Davies, P.F., Lab. Invest. 55:5 (1986); Munro, J.M. et al . , Lab. Invest. 58:249 (1988)), and, there- fore, local mechanisms presumably are operative. On the other hand, systemic factors such as hypercholesterolemia may contribute indirectly to atherosclerotic lesion localization. In swine, hypercholesterolemia induces the production of a subpopulation of monocytes in the bone marrow, which unlike monocytes from normocholesterolemic animals respond to a monocyte-selective chemoattractant (Averill, L.E., Am. J. Pathol . 135:369 (1989); Gerrity, R.G., et al.. in Vascular Dynamics, Westerhof, N., et al . (eds.), Plenum Press, p. 237 (1989)). Such a chemoattractant has been found in areas of the pig aorta that are prone to develop foam cell lesions (Gerrity, R.G., et al . , Arteriosclerosis .5:55 (1985)). In addition, the monocytosis seen in these animals may facilitate onocyte recruitment. Endothelial hyperadhesive surface change may occur through protein synthesis-dependent or -independent mechan¬ isms. In acute inflammation, both mechanisms appear to be operative (Cybulsky, M.I., et al.. Am. J. Pathol. 135:227 (1989)). Protein synthesis-dependent mechanisms involve the expression of endothelial-leukocyte adhesion molecules (ELAMs) (Cotran, R.S., et al.. J. EXP. Med. 164:661 (1986); Munro, J.M., et al.. Am. J. Pathol. 135:121 (1989)), and signify endothelial activation (Cotran, R.S., et al ., in Endothelial Cell Biology, Simionescu, N., et al . (eds.), Plenum Publish- ing, New York, p. 335 (1988)). Several such endothelial surface structures have been identified, including endothelial leukocyte adhesion molecule-1 (ELAM-1) (Bevilacqua, M.P., et al.. Proc. Nat! . Acad. Sci. USA: 84:9238 (1987); Bevilacqua, M.P., et al.. Science 243:1160 (1989)), ICAM-1 (Smith, C.W., et al.. J. Clin. Invest. 83:2008 (1989); Simmons, D., et al .. Nature 331:624 (1988); Staunton, D.E., et al.. Cell 52:925 (1988)), ICAM-2 (Staunton, D.E., et al .. Nature 339:61 (1989)), INCAM-110 (Rice, G.E., et al .. Science 246:1303 (1989)), and VCAM-1 (Osborn, L., et al.. Cell 59:1203 (1989)). In cultured EC and in inflammatory reactions, their expression is upregulated by bacterial endotoxin (lipopolysaccharide, LPS) and inflammatory cytokines (interleukin-1, IL-1, and tumor necrosis factor, TNF). Certain of these EC adhesion molecules exhibit leukocyte selectivity, e.g., ELAM-1 appears to primarily support the adhesion of neutrophils, not lymphocytes or lymphoid cell lines. ICAM-1, through its interaction with CDlla/CD18, may be involved in various EC-leukocyte interactions (Springer, T.A., Nature 346:425-434 (1990)). In contrast to ELAM-1 and ICAM-1, VCAM-1, also identified as INCAM-110 (Rice, G.E. et al., J. EXP. Med. 121:1369 (1990)), is a leukocyte adhesion molecule that supports the adhesion of human monocytes, lymphocytes, myelomonocytic and lymphocytic leukocyte cell lines, but not of peripheral blood neutrophils (Osborn, L. et L, Cell 59:1203 (1989), Rice, G.E. et al . , J. EXP. Med. 171:1369 (1990)). The patterns of ELAM distribution has been examined predominantly in normal tissues and in inflammatory condi¬ tions. ELAM-1 is not expressed by normal adult tissues and, in inflammation, is induced only in endothelium of post- capillary venules and small veins (Cotran, R.S. et al . , J L EXP. Med. 164:661-666 (1989); Cotran, R.S. et al . , J. Immunol. 140:1883-1886 (1988); Munro, J.M. et al .. Am. J. Pathol. 135:121-133 (1989)). ICAM-1 is expressed constitutively in endothelium and other cell types (Dustin, M.L. et al . , jL . Immunol . 117:245-254 (1986)), but can be upregulated in various pathophysiologic settings. In inflammatory reactions, enhanced endothelial expression of ICAM-1 is limited predo i- nantly to postcapillary venules and small veins (Cotran, R.S. et al., J. Immunol. 140:1883-1886 (1988); Munro, J.M. et al . , Am. J. Pathol. 135:121-133 (1989)); however, it also has been detected in endothelium of normal arterioles (Faull, R.J. and Russ G.R., Transplant 48:226-230 (1989)). None of the previously described ELAMs have been demonstrated in atherosclerotic lesions or implicated in the development and/or progression of such lesions. SUMMARY OF THE INVENTION The invention relates to protein molecules, designated ATHERO-ELAMs, expressed by endothelial cells. ATHERO-ELAMs are selective for mononuclear leukocytes, are involved in monocyte and lymphocyte adhesion to endothelial cells, and are markers for early atherosclerotic lesions in blood vessels. The invention also relates to monoclonal antibodies specific for an ATHERO-ELAM and uses of these monoclonal antibodies in diagnosis of atherosclerosis and in intervention during its progression. The invention further relates to the use of soluble forms of ATHERO-ELAMs to intervene with the progression of atherosclerosis. DESCRIPTION OF THE FIGURES Figure 1A is a graph which plots the level of adhesion of U937 cells to aortic endothelial cells (Ao EC) and inferior vena cava cells (IVC EC). Adhesion is measured as a function of time after activation of endothelial cells with E. coli LPS (1 μg/ml). Figure IB is a bar graph which shows the effect of cyclohexa ide (CHX, 10 μg/ml) on adhesion of U937 cells to IVC EC at 0 hours and 5 hours after activation of the IVC EC with LPS. Figure 1C is a graph which plots the binding of monoclonal antibodies (MAb) Rb2/3 and Rbl/9 to Ao EC and of monoclonal antibody Rbl/9 to IVC EC. MAb binding is measured as a function of time after activation of endothelial cells with E. coli LPS (lμg/ml). Figure ID is a bar graph which shows the effect of cyclohexamide on the binding of MAb Rbl/9 to IVC EC at 0 hours and 5 hours after activation of the IVC EC with LPS. The inset in figure ID shows that CHX did not affect the binding of MAb Rb2/3 to an EC antigen, the expression of which was not altered by LPS. Figure 2 consists of two bar graphs. The bar graph on the left shows the adhesion of U937 cells to venous EC at 5 and 24 hours after activation by LPS. The bar graph on the right shows the effect of MAb Rb 1/9, Rb2/4 and Rb2/3 pretreatment on adhesion of U937 cells to venous EC at 0, 5 hours and 24 hours after activation of the EC cells by LPS. Figure 3 is a bar graph illustrating the inhibition of leukocyte adhesion with F(ab')2 fragments to 18 h LPS-treated rabbit aortic endothelium. At 4 β C (open bars), Rbl/9 F(ab')2 significantly inhibited the adhesion of U937, HL60 and THP-1 cell lines, as well as human blood monocytes and lymphocytes (upper panel). U937 and HL60 adhesion was also inhibited in assays performed at 37 β C (solid bars). Significant decreases in adhesion were not observed with Rb2/4 or Rb2/3 F(ab')2 (middle and lower panels). Figure 4 is a photograph illustrating immunohistochemical staining of rabbit aortas. (A-D) Frozen sections of the same atherosclerotic lesion located in the descending thoracic aorta from a rabbit fed a 1% cholesterol diet for 9 weeks (arrowhead marks edge of lesion). (A) Stained for smooth muscle cells with MAb CGA7. (B) Stained for rabbit macro- phages with MAb RAM 11. (C,D) Stained for ATHERO-ELAM with Rbl/9. (C inset, goat anti-human von Willebrand Factor, 1/3000 di1. of IgG, Atlantic Ab., bar = 50 μm) . (D inset, culture supernatant, bar = 10 μm). (E) Rbl/9 staining of EC overlying an intimal foam cell-rich lesion in the aortic arch of an 18-week WHHL rabbit (bar = 10 μm) . (F) Focal ATHERO- ELAM expression associated with small foam cell aggregates in the descending thoracic aorta of a rabbit with dietary hypercholesterolemia (bar = 100 μm). Figure 5 A and B illustrate autoradiograms of reduced SDS-polyacrylamide gels, demonstrating specific indirect immunoprecipitation of polypeptides with MAb Rbl/9. Figure 6 illustrates the homology between the N-terminal amino acid sequence of purified 98K ATHERO-ELAM (Sequence ID 2, amino acids 1-22) and the predicted N-terminal sequence of human VCAM-1 (Sequence ID 7, amino acids 1-22). Figure 7 illustrates the nucleotide sequence of rabbit ATHERO-ELAM (Sequence ID 1). The underlined region in the Figure indicates a newly identified alternatively spliced region designated AS-III. Rabbit ATHERO-ELAM was cloned using an oligonucleotide probe based on the N-terminal amino acid sequence (Figure 6) from a lambda gtll cDNA library constructed with mRNA from LPS-stimulated (4hr) rabbit venous endothelium. Fiqure 8 illustrates the deduced amino acid sequence of rabbit ATHERO-ELAM (Sequence ID 2). Figure 9 illustrates and compares the nucleotide sequences of rabbit ATHERO-ELAM (Sequence ID 6) and human VCAM-1 (Sequence ID 3) AS-I domains. Figure 10 illustrates the nucleotide sequence, deduced amino acid sequence, and location of an alternatively spliced human exon designated AS-I (Sequence ID 3 and 5) with respect to human VCAM-1 cDNA. The potential N-linked glycosylation site is underlined. Figure 11 illustrates the extracellular structure of the 7 immunoglobulin-like domain form of human VCAM-1 (Sequence ID 7). The sequence was aligned to residues conserved in C2 or H type immunoglobulin regions (Hunkapiller, T., et al .. Adv. in Immunol. 44:1-63 (1989)). Cysteine residues forming disulfide bridges in each domain are indicated with arrowheads. Figure 12 illustrates the structural homology between human AS-I (Sequence ID 5) and domain 1 (Sequence ID 7, amino acids 1-89). Sequences were aligned by inspection, and homologous regions boxed (AS-I, top; domain 1, bottom). Figure 13A illustrates the identification of 7 and 6 immunoglobulin-like domain forms of VCAM-1 in IL-1-activated human umbilical endothelium. PCR was performed with primers corresponding to regions of domains 3 and 5 as indicated by the upper arrows. These primers should generate 740 and 464 bp products from VCAM-1 cDNA with and without the AS-I domain respectively. Southern blotting using oligonucleotide probes corresponding to the underlined regions of domains 3, AS-I, and 4 confirmed the presence of both species. As expected, the domain 3 and 4 probes hybridized to both 740 and 464 bp species, whereas the AS-I probe only to the 740 bp product. A domain 2 probe, which was 5' of the region amplified by PCR, did not hybridize with either product (right lane). All the above probes hybridized to a 2.05 kb PCR product generated with primers spanning the 7 extracellular immunoglobulin-like domains of VCAM-1 (results with domain 2 probe shown, left lane). Relevant hybridization is indicated by arrowheads. Molecular weight standards are bacteriophage lambda DNA digested with Hind III and Bst E II (right). Figure 13B is a photograph of an autoradiogram of a reduced SDS polyacryl ami de gel demonstrating immunoprecipitation of a 110 kD polypeptide from surface- iodinated, TNF-treated (24h) human umbilical vein endothelial cells with MAb El/6 (C is a control, nonbinding MAb). Identical results were obtained with MAb Hu8/4, which like El/6 is directed to human VCAM-1. Figure 14 illustrates the amino acid sequences of human VCAM-1 (Sequence ID 7) and rabbit ATHERO-ELAM (Sequence ID 2). The sequences were aligned as in Figure 11. SP = Signal Peptide; TM/Cyto: Transme brane and cytoplas ic region; the transmembrane region is underlined. A human AS-III exon region corresponding to the rabbit AS-III exon has been identified. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel ELAM, designated ATHERO-ELAM. By "ATHERO-ELAM" is meant an endothelial cell surface protein expressed at sites of ongoing/active atherosclerosis which participates in leukocyte-endothelial adhesion. By "VCAM-l" is meant a member of the immunoglobulin gene superfamily, which is induced on the surface of endothelial cells by certain cytokines. By "in substantially pure form" in reference to a protein is meant that the protein is free of other components of biological origin. By "binding characteristics" in reference to an antibody is meant a molecule capable of recognizing and binding to the protein or fragment thereof for which the antibody is specific. By " onocyte-binding equivalent" or "mononuclear leukocyte-binding equivalent" in reference to a protein or polypeptide is meant a second protein or fragment thereof which is also capable of binding to a monocyte or mononuclear leukocyte, despite differing from the protein or polypeptide by one or more* amino acids. By "water-soluble part of ATHERO-ELAM" is meant the extracellular part of ATHERO-ELAM. According to the invention, the water-soluble part contains amino acids 1 - 774 of Sequence ID 2. Induction and Assays of ATHERO-ELAM ATHERO-ELAM can be induced in endothelial cells by bacterial endotoxin, lipopolysaccharide (LPS). In culture, the inducible endothelial cell surface protein supports adhesion of onocyte-like U937 cells. U937 adhesion becomes increased over basal levels after 1-2 hours of LPS treatment, reaches a maximum at 6-8 hours, and remains sustained through 96 hours. Inhibition of protein synthesis with cycloheximide prevents this adhesive change. Initially, an in vitro system was developed to facilitate the study of monocyte-endothelial adhesive interactions. EC cultures were established from large vessels (aorta and inferior vena cava) of normal New Zealand White rabbits. From everted vessels, EC were isolated with 0.2% or 0.4% colla- genase respectively, and cultured on gelatin-coated tissue culture plastic in Medium 199 (Hank's salts) containing 20% fetal bovine serum (FBS), 10-20 μg/ml EC mitogen (Biomedical Technologies, Inc.), and 20-40 μg/ml porcine intestinal heparin (Sigma, grade I) (Cybulsky, M.I. et al .. FASEB J. 2:A1603 (1988); Danthuluri, N.R. et al .. Am. J. Phvsiol. 255 (Heart Circ. Physio! . 24):H1549-H1553 (1988)). These cells grew to form confluent onolayers that exhibited features characteristic of differentiated endothelium. Activation of rabbit EC with Gram negative bacterial endotoxin (lipopoly- saccharide, LPS) resulted in a hyperadhesive surface change that was demonstrable with rabbit leukocytes (Cybulsky, M.I. et al.. FASEB J. 3:A1319 (1989)) and human blood monocytes (Territo, M.C. et al .. Arteriosclerosis 9:824 (1989); Berliner, J.At et al.. J. Clin. Invest. 85:1260 (1990)). The U937 cell, a human leukocyte cell line with adhesive properties similar to monocytes (DiCorleto, P.E. et al .. J Clin. Invest. 75:1153 (1985)) was selected to further charac¬ terize this adhesive change. The human promyelocytic HL60 cell line was used for comparison. U937 adhesion to rabbit aortic and venous EC became increased over basal levels after l-2h of LPS treatment, reached maximum at 6-8h and remained sustained through 96h. Inhibition of protein synthesis with cycloheximide abrogated this adhesive change. Similar results were obtained with HL60 cells. Monoclonal Antibodies to ATHERO-ELAM In order to identify ELAMs mediating the increase in U937 adhesion, monoclonal antibodies (MAb's) to inducible EC surface antigens were produced. From a panel of MAb's generated to LPS-activated EC, three MAb's, designated Rbl/9, Rb2/3 and Rb2/4 (all IgG j immunoglobulins), were selected for their ability to recognize LPS-inducible EC surface antigens in a cell surface fluorescence immunoassay. The time course of binding of MAb Rbl/9 was similar to the EC adhesive change for U937 cells (low in untreated EC, reaching maximum in 6-8h and sustained through 96h), and cycloheximide treatment ablated Rbl/9 antigen surface expression both in basal and activated monolayers. The binding profile of MAb Rb2/4 was virtually identical to that of Rbl/9, whereas MAb Rb2/3 recognized a surface epitope with higher basal expression and a sustained LPS-induced elevation. The functional role of these inducible EC surface antigens in supporting U937 adhesion was then assessed in adhesion blocking assays. Pretreatment with saturating concentrations of Rbl/9 significantly inhibited U937 adhesion to basal and 5h- or 24h-activated EC monolayers. In contrast, a decreased acjhesion was not observed with other MAb's of the same immunoglobulin class, including Rb2/4 which appears to recognize the same molecule as Rbl/9, and Rb2/3 which bound to basal and activated EC surfaces at higher densities than Rbl/9. MAb Rb2/13, which recognized a constitutive antigen expressed at high levels on control and LPS-treated rabbit EC, also did not inhibit U937 adhesion. None of the MAb's inhibited HL60 cell adhesion. These results demonstrate the specificity of Rbl/9 in blocking adhesion of monocyte-like U937 cells, and implicate the Rbl/9-binding epitope as important to adhesion of mononuclear leukocytes. Having identified an inducible EC surface protein which appeared to support mononuclear cell adhesion in vitro, an immunohistochemical technique was used to examine its expres¬ sion in atherogenesis. In rabbits fed a 1% hypercholesterol- emic diet and in Watanabe heritable hyper!ipidemic (WHHL) rabbits, specific staining with Rbl/9 was localized to aortic endothelium covering foam cell-rich intima! lesions at various stages of their development. Of particular interest was staining of EC extending beyond the edges of intimal lesions, and focally in regions with very small intimal accumulations of foam cells. Aortic EC in uninvolved regions of these hypercholesterole ic animals, as well as EC in large arteries and veins of normal rabbits, were uniformly unstained. This selective pattern of immunohistochemical staining establishes the inducible ELAM recognized by Rbl/9 as an ATHERO-ELAM. The biochemical nature of Rbl/9 antigen was determined by immunochemical studies and amino acid sequencing. From total cell lysates of biosynthetically labeled LPS-activated EC monolayers, Rbl/9 specifically immunoprecipitated two poly- peptides, with relative molecular weights of 118K and 98K on reduced SDS-PAGE. Both polypeptides appeared to be expressed on the EC surface, as determined by immunoprecipitating cell lysates from surface iodinated monolayers. The relationship of the polypeptides was further investigated by Western blotting. The Rbl/9-binding epitope was found on both polypeptides, which suggests that they are not a heterodimeric complex. Together, these immunochemical data indicate that the inducible molecule recognized by MAb Rbl/9 is a newly synthesized protein, expressed on the EC surface in two forms. MAb Rb2/4 produced a similar immunoprecipitation pattern to Rbl/9, and cross-over immunoprecipitation established that both MAb recognized the same protein. Structure of ATHERO-ELAM and Nucleotide Sequence Encoding ATHERO-ELAM To elucidate the primary structure of the 2 polypeptides recognized by Rbl/9, they were purified from lungs of LPS- treated rabbits by immunoaffinity chromatography and SDS-PAGE, electrotransferred to Immobilon-P and N-terminal amino acid sequences obtained. The 98K band showed high homology (20 of 22 amino acids, Figure 6; Sequence ID 2, amino acids 1-22) to the predicted N-terminal sequence of human VCAM-1 (Sequence ID 7, amino acids 1-22), a recently cloned cytokine-inducible member of the immunoglobulin gene superfamily (Osborn, L., et al .. Cell 59:1203-1211 (1989)). VCAM-1 has been identified on the surface of human EC and mediates the binding of mononuclear lymphocytes to EC. Expression of VCAM-1 by human EC was induced by the inflammatory cytokines interleukin-1 and tumor necrosis factor-alpha (Osborn et al .) . ATHERO-ELAM was cloned from a rabbit endothelial lambda gtll cDNA library using an oligonucleotide probe based on the N-terminal amino acid sequence (Figure 6; Sequence ID 1, amino acids 1-22). ATHERO-ELAM cDNA clones (the nucleotide sequences of the open reading frame are displayed in Figure 7; Sequence ID 1) encoded two transmembrane proteins; one with 8, the other with 7 extracellular immunoglobulin-like domains (Figure 14). These two proteins were identical, except for the presence of an additional extracellular immunoglobulin- like domain adjacent to the transmembrane domain. This domain, designated AS-III, is the result of alternative mRNA splicing. The AS-III domain is encoded by 267 base pairs, having the sequence of nucleotides 2060-2326 in the rabbit ATHERO- ELAM open reading frame (Figure 7, underlined sequence; Sequence ID 7, nucleotides 2060-2326). The presence of two forms of ATHERO-ELAM, which arise by alternative mRNA splicing, accounts for the two distinct polypeptides identified by immunoprecipitation with MAb Rbl/9 (Figure 5), each sharing the same N-terminal amino acid sequences (Figure 6). The AS-III domain was not identified in the published sequence of human VCAM-1 (Osborn, L., et al . , Cell 59:1203- 1211 (1989)). Six of the rabbit ATHERO-ELAM extracellular immunoglobulin-like domains are highly homologous to the published sequence of human VCAM-1 (Osborn, L. et al ., Cell 59:1203-1211 (1989); Figure 14; Sequence ID 2). In addition to the AS-III domain, a second new immunoglobulin-like domain • was identified. This domain, designated AS-I, is located between domains 3 and 4 (Figure 14), is composed of 276 base pairs, and is encoded by nucleotides 929-1204 in Figure 7 (Sequence ID 6). AS-I was present in all of the rabbit ATHERO-ELAM cDNA clones spanning this region (Figure 14; Sequence ID 2). Identification of the AS-I Domain in Human VCAM-1 In order to identify the AS-I domain in human VCAM-1 and to further compare ATHERO-ELAM and VCAM-1, a partial cDNA corresponding to the extracellular region of VCAM-1 was generated by. PCR from IL-1-stimulated human umbilical vein endothelial cell (HUVEC) mRNA. This cDNA was 2.05 kb in length, and about 0.25 kb longer than would be predicted from the published human VCAM-1 sequence (Osborn et al .). Based on sequencing, the coding region of this amplified cDNA was identical to the previously reported VCAM-1 HUVEC cDNA clone (Osborn et al . ) from amino acid residue 1 to 309 (Sequence ID 7), at which point the sequences diverge. At the nucleotide level, the sequences were identical to bp 1034 of the published sequence, and after an insertion of 276 bp (Fig. 10; Sequence ID 3), the two sequences resumed identity. The difference in the transcript structure lengthens the predicted protein by 92 residues between the third and fourth immunoglobulin domains. The amino acid sequence of this additional region was homologous to the rabbit ATHERO-ELAM AS-I domain (Figure 9). AS-I is an immunoglobulin-like domain of the C2 or H type, (Hunkapiller, T., et al.. Adv. in Immunol. 44:1-63 (1989)), consistent with the other 6 extracellular domains of VCAM-1. Furthermore, this sequence was 73% homologous with the N- terminal immunoglobulin-like domain (domain 1) (Fig. 12; AS-I, Sequence ID 5; Domain 1, Sequence ID 7, amino acids 1-89). The AS-I domain also contains an additional potential N-linked glycosylation site. To demonstrate that two VCAM-1 transcripts were derived by alternative mRNA splicing, the corresponding region of the human VCAM-1 gene was cloned from a human genomic library. A phage clone was obtained by screening a human genomic library with a rabbit partial cDNA. The AS-I domain corresponded to a single exon located between exons containing domains 3 and 4. Splice donor and acceptor sequences flanking the AS-I exon conform to consensus (Smith, C.W.J., et al . , Ann. Rev. Genet. 23 . :527-577 (1989)). The nucleotide sequence of the AS-I exon was identical to that of the cDNA sequence obtained by PCR amplification. The 2.05 kb product generated by PCR amplification * of VCAM-1 extracellular domains (Fig. 13A) suggested that a 7 domain form was the predominant mRNA species. In order to confirm that IL-1-activated HUVEC express both forms of VCAM-1 mRNA, nested PCR was utilized. The same primers were used for first strand cDNA synthesis and first round PCR (see Example 15), however, nested primers were selected to regions in domains 3 and 5 (AATTTATGTGTGTGAAGGAG, Sequence ID 8 and TTCTGTGAATATGACAT, Sequence ID 9, respectively). By ethidium bromide staining and Southern blotting with oligonucleotide probes to regions of domain 3, AS-I and 4, the predominant PCR product was 740 bp (Fig. 13A), consistent with the 7 domain form. However, a 464 bp product which did not hybridize the AS-I probe was also identified, confirming that the 6 immunoglobulin domain form of VCAM-I was expressed by HUVEC. The observation that the 7 domain VCAM-1 mRNA is predominant in activated HUVEC is consistent with expression of a HOkD protein, determined by immunoprecipitation of biosynthetically labeled cells with monoclonal antibody El/6 (Rice, G.E., et al .. Science 246:1303-1306 (1989)). El/6 blocked leukocyte adhesion to activated HUVEC (Rice, G.E., et al.. Science 246:1303-1306 (1989); Rice, G.E., et al .. i. EXP. Med. 121:1369-1374 (1990)), and immunoprecipitation of surface iodinated HUVEC with MAbs El/6 and Hu8/4 detected only the HOkD polypeptide. (Figure 13B) . Together, these data suggest that on the activated HUVEC surface, it is the 7 domain form which supports adhesion of mononuclear leukocytes. The 6 domain VCAM-1 cDNA expressed on transfected COS cells also supports mononuclear leukocyte adhesion (Osborn, L., et al . ♦ Cell 59:1203-1211 (1989); Elices, M.J., et al.. Cell 60:577-584 (1990)). In light of the present demonstration of alternative splicing of the human VCAM-1 gene, it is possible that the 7 and 6 domain forms may have different affinities or subtle differences in specificities. DESCRIPTION OF THE PREFERRED EMBODIMENTS The DNA encoding ATHERO-ELAM can be utilized to produce genetic constructs which encode a soluble form of ATHERO-ELAM. Soluble transmembrane proteins can be produced by genetically engineering a cDNA containing a termination codon immediately 5' of the transmembrane domain. When expressed in appropriate cells, the protein synthesized from this cDNA is secreted and can be recovered from the culture medium. The invention further relates to antibodies which recognize ATHERO-ELAM. Antibodies which recognize ATHERO-ELAM may be prepared by immunizing mice with cultured rabbit inferior vena cava (IVC) cells, which have been activated with LPS. Spleen cells from the immunized mice are fused with myeloma cells using methods known in the art (Kohler, G., et al.. Nature 256:495 (1975); Goding, J.W., Monoclonal Anti¬ bodies: Principles and Practice, 2nd ed., Academic Press, London (1986)). Screening of the hybridomas with. LPS-treated and control EC cells allows selection of monoclonal antibodies capable of binding to LPS-induced cell surface molecules. Further selection of monoclonal antibodies specific for ATHERO-ELAM is accomplished by determining the ability of the monoclonal antibodies to inhibit adhesion of monocyte-like U937 cells to control and activated EC cells. Monoclonal antibody Rbl/9 is particularly effective in blocking U937 adhesion to activated EC monolayers. However, other monoclonal antibodies having the binding characteristics of the monoclonal antibodies described herein may also be utilized. The ability to block U937 adhesion to activated EC monolayers and the ability to bind to a newly synthesized protein, ATHERO-ELAM, on the activated EC surface, are binding characteristics of Rbl/9. The ability to bind to a newly synthesized protein, ATHERO-ELAM, on the activated EC surface, is a binding characteristic of Rb2/4. Antibodies to ATHERO-ELAM may also be prepared by immunizing mice with recombinant ATHERO-ELAM, or ATHERO-ALAM fragments. By "ATHERO-ELAM" fragment is meant any polypeptide subset of the molecule. Particularly preferred ATHERO-ELAM fragments include monocyte-binding fragments. The monocyte- binding fragments may be obtained by cutting the ATHERO-ELAM cDNA with various restriction enzymes or exonucleases, cloning the resulting fragments, expressing these, and screening for monocyte binding activity according to methods known in the art. The joining of various DNA fragments is performed in accordance with conventional procedures, employing blunt-ended or staggered-ended termini for ligation, restriction enzyme digestion to provide appropriate termini, filing in of cohesive ends as appropriate, alkali and phosphatase treatment to avoid undesirable joining, and ligation with appropriate ligases. The genetic construct may optionally encode a leader sequence to allow efficient expression of the recombinant protein. To express the recombinant ATHERO-ELAM, transcriptional and translational signals recognized in an appropriate host element are necessary. Mammalian cells provide post-trans!a- tional modification to recombinant protein molecules which provide for correct folding and glycosylation of appropriate sites. Mammalian cells which may be used in the practice of the invention include COS cells, Chinese hamster ovary (CHO) cells, leukocytes, myeloma cells or other transformed or oncogenic lymphocytes, e.g. EBV-transformed cells, cells of fibroblast origin such as VERO or cells of lymphoid origin, such as hybridoma SP2/0-AG-14 or the myeloma P3x63Sgh, and their derivatives. Other hosts include BHK cells and hepatoma cells. , In general, vectors containing replicon and control sequences which are derived from species compatible with a host cell are used in connection with the host. The vector ordinarily carries a replicon site, as well as specific genes which are capable of providing phenotypic selection in transformed cells. The expression of the gene encoding ATHERO-ELAM can also be placed under control with other regulatory sequences which may be homologous to the cell line in its untransformed state. For example, lactose-dependent E coli chromosomal DNA comprises a lactose or lac operon which mediates lactose utilization by elaborating the enzyme beta- galactosidase. The lac control elements may be obtained from bacterial phage lambda placδ, which is infective for E. coli. The lac promoter-operator system can be induced by IPTG. Other promoter/operator systems or portions thereof can be employed as well. For example, colicin El, galactose, alkaline phosphatase, tryptophan, xylose, and the like can be used. For mammalian hosts, several possible vector systems are available for expression. One class of vectors utilize DNA elements which are derived from animal viruses such as bovine papilloma virus, polyoma virus, adenovirus, vaccinia virus, baculovirus, retroviruses (RSV, MMTV or MOMLV), or SV40 virus. Cells which have stably integrated the DNA into their chromo¬ somes may be selected by introducing one or more markers which allow selection of transfected host cells. The marker may provide for prototropy to an auxotrophic host, biocide resistance, e.g., antibiotics, or heavy metals such as copper or the like. The selectable marker gene can be either directly linked to the DNA sequences to be expressed, or introduced into the same cell by cotransformation. Additional elements may also be needed for optimal synthesis of mRNA. These elements may include splice signals, as well as tran- scriptional promoters, enhancers, and termination signals. The cDNA expression vectors incorporating such elements include those described by Okayama, H., Mol . Cel . Biol., 3:280 (1983) and others. Once the vector or DNA sequence containing the constructs has been prepared for expression,, the DNA constructs may be introduced into an appropriate host. Various techniques may be employed, such as protoplast fusion, calcium phosphate precipitation, electroporation or other conventional tech¬ niques. After transfection, the cells are grown in media and screened for the appropriate activity using, for example, the above-described antibodies. Expression of the gene(s) results in production of the ATHERO-ELAM. The transformed cells may be grown in appropriate nutrient medium in culture flasks or injected into a synergis- tic host, e.g., mouse or a rat, or immunodeficient host or host site, e.g., nude mouse or hamster pouch. In particular, the cells may be introduced into the abdominal cavity of an animal to allow production of ascites fluid which contains ATHERO-ELAM, or a fragment thereof. Alternatively, the cells may be injected subcutaneously and ATHERO-ELAM is harvested from the host. The cells may be used in the same manner as hybrido a cells. The expressed ATHERO-ELAM, or fragment thereof, may be isolated from fermentation media or cell culture and purified in accordance with conventional conditions, such as extrac- tion, precipitation, chromatography, affinity chromatography, electrophoresis or the like. For example, ATHERO-ELAM may be purified by passing a solution containing the surface protein through a column containing an immobilized antibody which is specific for ATHERO-ELAM, for example, the above-described antibody Rbl/9. The desired protein may then be eluted by lowering the pH of the eluant. . It is also possible to use antibodies directed to ATHERO- ELAM to detect the presence of ATHERO-ELAM in tissue samples as an indication of expression of ATHERO-ELAM in association with disease processes. Thus, the invention also relates to a method of detecting endothelial cell expression of ATHERO- ELAM in a mammal by an assay for ATHERO-ELAM, comprising contacting a detectably labeled antibody directed to ATHERO- ELAM with a sample suspected of containing ATHERO-ELAM, or cell which expresses ATHERO-ELAM on its surface, and detecting whether a complex has formed. The detection and quantitation of antigenic substances and biological samples frequently utilize im unoassay techni¬ ques. These techniques are based upon the formation of a complex between the antigenic substance being assayed, e.g., ATHERO-ELAM, and an antibody or antibodies in which one or the other member of the complex may be detectably labeled. In the present invention, the ATHERO-ELAM specific antibody may be labeled with any conventional label. Thus, in this aspect of the invention, a biological sample may be treated with nitrocellulose, or other solid support which is capable of immobilizing cells, cell particles or soluble protein. The support may then be washed with suitable buffers followed by treatment with the detectably labeled ATHERO-ELAM specific antibody. The solid phase support may then be washed with the buffer a second time to remove unbound antibody. The bound label on the antibody may then be detected by conventional means. Labeled ATHERO-ELAM specific antibody/ATHERO-ELAM complex in a sample may be separated from a reaction mixture by contacting the complex with an immobilized antibody or protein which is specific for an immunoglobulin, e.g., protein A, protein G, anti-IgM or anti-IgG antibodies. Such anti- immunoglobulin, antibodies may be monoclonal or polyclonal. The solid support may then be washed with a suitable buffer to give an immobilized ATHERO-ELAM/labeled ATHERO-ELAM specific antibody complex. The label on the protein may then be detected to give a measure of endogenous ATHERO-ELAM and, thereby, the extent to which endothelial cells are expressing ATHERO-ELAM. This aspect of the invention relates to a method for detecting ATHERO-ELAM or monocyte-binding fragment thereof in a sample comprising (a) contacting a sample suspected of containing ATHERO-ELAM with an ATHERO-ELAM specific antibody or fragment thereof which binds to ATHERO-ELAM; (b) detecting whether a complex is formed. The invention also relates to a method of detecting ATHERO-ELAM in a sample, further comprising (c) contacting the mixture obtained in step (a) with an Fc binding molecule, such as an antibody, protein A, or protein G, which is immobilized on a solid phase support and is specific for the ATHERO-ELAM specific antibody to give a ATHERO-ELAM/ATHERO-ELAM specific antibody-immobilized antibody complex; (d) washing the solid phase support obtained in step (c) to remove unbound ATHERO-ELAM/ATHERO- ELAM specific antibody complex; (e) and detecting the label on the ATHERO-ELAM specific antibody. Of course, the specific concentrations of detectably labeled antibody and ATHERO-ELAM, the temperature and time of incubation, as well as other assay conditions may be varied, depending on various factors including the concentration of ATHERO-ELAM in the sample, the nature of the sample, and the like. Those 4 skilled in the art will be able to determine operative and optimal assay conditions for each determination by employing routine experimentation. One of the ways in which the ATHERO-ELAM specific antibody can be detectably labeled is by linking the same to an enzyme. This enzyme, in turn, when later exposed to its substrate, will react with the substrate in such a manner as to produce a chemical moiety which can be detected, for example, by spectrophotometric, fluorometric or by visual means. Enzymes which can be used to detectably label the ATHERO-ELAM specific antibody include, but are not limited to, ma!ate dehydrogenase, staphylococcal nuclease, delta-V- steroid isomerase, yeast alcohol dehydrogenase, alpha-glycero- phosphate dehydrogenase, triose phosphate isomerase, horse¬ radish peroxidase, alkaline phosphatase, asparaginase, glucose oxidase, beta-galactosidase, ribonuclease, urease, catalase, glucose-VI-phosphate dehydrogenase, glucoamylase and acetylcholine esterase. The ATHERO-ELAM specific antibody may also be labeled with a radioactive isotope which can be determined by such means as the use of a gamma counter or a scintillation counter or by autoradiography. Isotopes which are useful for the purpose of the present invention are well known in the art. It is also possible to label the ATHERO-ELAM specific antibody with a fluorescent compound. When the fluorescently labeled antibody is exposed to light of the proper wave length, its presence can then be detected due to the fluores- cence of the dye. Among the most commonly used fluorescent labelling compounds are fluorescein isothiocyanate, rhodamine, phycoerytherin, phycocyanin, allophycocyanin, o-phthaldehyde and fluorescamine. The ATHERO-ELAM specific antibody can also be detectably labeled using fluorescence emitting metals. These metals can be attached to the ATHERO-ELAM specific antibody using such metal chelating groups as diethylenetriaminepentaacetic acid (DTPA) or ethylenediaminetetraacetic acid (EDTA). The ATHERO-ELAM specific antibody also can be detectably labeled by coupling it to a chemiluminescent compound. The presence of the chemiluminescent-tagged ATHERO-ELAM specific antibody is then determined by detecting the presence of luminescence that arises during the course of a chemical reaction. Examples of particularly useful chemiluminescent labeling compounds are luminol, isoluminol, theromatic acridinium ester, imidazole, acridinium salt and oxalate ester. Likewise, a bioluminescent compound may be used to label the ATHERO-ELAM specific antibody of the present invention. Bio uminescence is a type of chemiluminescence found in biological systems in which a catalytic protein increases the efficiency of the chemiluminescent reaction. The presence of a bioluminescent protein is determined by detecting the presence of luminescence. Important bioluminescent compounds for purposes of labeling are luciferin, luciferase and aequorin. Detection of the ATHERO-ELAM specific antibody may be accomplished by gamma scintillation counters, for example, if the detectable label is a radioactive gamma emitter, or by a fluorometer, for example, if the label is a fluorescent material. In the case of an enzyme label, the detection can be accomplished by colorimetric methods which employ a substrate for the enzyme. Detection may also be accomplished by visual comparison of the extent of enzymatic reaction of a substrate to similarly prepared standards. Expression of ATHERO-ELAM can be detected using immuno¬ globulins, or fragments thereof, capable of recognizing and binding to the antigen. Furthermore, the antibodies may be labeled to permit their detection following administration to a mammal. The immunoglobulins can be polyclonally or mono- clonally deriyed. If desired, polyclonal immunoglobulin preparations may be prepared from the blood of immunized individuals of the desired species following immunization with ATHERO-ELAM followed by harvesting of the blood and processing it accord¬ ing to defined techniques. A distinct advantage of non¬ specific, polyclonal immunoglobulin preparations is that by preparing immunoglobulin from the same species into which it will be injected, immune reactions across species barriers are prevented and repeated injections of the same product are less likely to cause side-effects. Monoclonal immunoglobulins which can be used according to the method of the invention can be prepared using hybridoma fusion techniques (Kohler et al . , European Journal of Immunol¬ ogy 6:292, 1976) or can be derived from known secreting myeloma cell lines such as those available from depositories such as the American Type Culture Collection. In detecting early atherosclerotic development in an individual, the detectably labeled immunoglobulin is advan¬ tageously given in a dose which is diagnostically effective. The term "diagnostically effective" means that the amount of detectably labeled immunoglobulin administered is sufficient to enable detection of the site of the atherosclerotic plaque when compared to the background signal. Generally, the dosage of detectably labeled immuno¬ globulin for diagnosis will vary depending on considerations such as age, condition, sex, and extent of disease in the patient. The dosage will also depend on counterindications, if any, and other variables, to be adjusted by the individual physician. Dosage can vary from 0.01 g/kg to 2,000 mg/kg, preferably 0.1 mg/kg to 1,000 mg/kg. The term "immunoglobulin or a fragment thereof" as used herein is meant to include intact molecules as well as fragments thereof, such as, for example, the Fab and F(ab)£ fragments, whiich are capable of binding to antigenic determi¬ nants of the graft tissue. The term "diagnostically labeled" means that the immuno¬ globulin has attached to it a diagnostically detectable label. There are many different labels and methods of labeling known to those of ordinary skill in the art. Examples of the types of labels which can be used in the present invention include radioactive isotopes and paramagnetic isotopes. Those of ordinary skill in the art will know of other suitable labels for binding to the immunoglobulins used in the invention, or will be able to ascertain such, using routine experimentation. Furthermore, the binding of these labels to the immunoglobulin can be done using standard techniques common to those of ordinary skill in the art. For diagnostic in vivo imaging, the type of detection instrument available is a major factor in selecting a given radionuclide. The radionuclide chosen must have a type of decay which is detectable for a given type of instrument. In general, any conventional method for visualizing diagnostic imaging can be utilized in accordance with this invention. Another important factor in selecting a radionuclide for in vivo diagnosis is that the half-life of a radionuclide be long enough so that it is still detectable at the time of maximum uptake by the target, but short enough so that dele¬ terious radiation upon the host is minimized. Ideally, a radionuclide used for in vivo imaging will lack a particulate emission, but produce a large number of photons in a 140-200 keV range, which may be readily detected by conventional gamma cameras. For in vivo diagnosis, radionuclides may be bound to immunoglobulin either directly or indirectly by using an intermediary functional group. Intermediary functional groups which are often used to bind radioisotopes which exist as metallic ions to immunoglobulins are diethylenetriaminepenta- acetic acid (DTPA) and ethylenediaminetetraacetic acid (EDTA). The immunoglobulins used in the method of the invention can also be labeled with paramagnetic isotypes for purposes of jn vivo diagnosis. Elements which are particularly useful (as in Magnetic Resonance Imaging (MRI) techniques) in this manner are known to those of skill in the art. This invention also relates to therapeutic uses for ATHERO-ELAM. In one embodiment, ATHERO-ELAM, or a monocyte- binding fraction thereof, may be administered to a patient to prevent adhesion of monocytes to endothelial tissue. Thus, ATHERO-ELAM, or a monocyte-binding fragment thereof, would prevent monocyte adhesion to endothelial cells which have undergone changes characteristic of the early stages in atherosclerotic lesion development. In one embodiment, a soluble form of ATHERO-ELAM may be administered. By "soluble form" is meant an ATHERO-ELAM molecule in which the transmembrane and cytoplasmic domains are deleted. The soluble form can be obtained by expression in a host cell of a genetic construct encoding a soluble form of ATHERO-ELAM. Monoclonal antibodies to ATHERO-ELAM may also be adminis¬ tered to block monocyte adhesion sites of endothelial cells expressing ATHERO-ELAM. These cells may be present in early atherosclerotic lesions, and subsequent progression of the lesions is prevented by blocking monocyte adhesion in the lesions. The ATHERO-ELAM molecule, or fragment thereof, or antibodies and antibody fragments directed to ATHERO-ELAM, can be formulated into pharmaceutically useful compositions according to known methods, such as by admixture with a pharmaceutically acceptable carrier vehicle. In order to form a pharmaceutically acceptable composition suitable for effective administration, such compositions will contain a therapeutically effective amount of the ATHERO-ELAM, soluble form of ATHERO-ELAM, fragment of ATHERO-ELAM, or antibody or antibody fragment directed to ATHERO-ELAM, either alone or with a suitable amount of carrier vehicle. When used for the prevention of monocyte adhesion to endothelial cells, the pharmaceutical composition may comprise from 1 pg/kg to 10 mg/kg of ATHERO-ELAM, a soluble form of ATHERO-ELAM, or fragment of ATHERO-ELAM, although higher or lower doses are possible. An antibody directed to ATHERO-ELAM may be conjugated with a drug to treat the atherosclerotic lesion. Examples of drugs useful for this purpose are anti-proliferative, anti- coagulant, anti-oxidant and anti-inflammatory drugs. Additional pharmaceutical methods may be employed to control the duration of action. Controlled release prepara¬ tions may be achieved by the use of polymers to complex or absorb the ATHERO-ELAM, ATHERO-ELAM fragment or antibody or antibody fragment directed to ATHERO-ELAM. Controlled delivery may be achieved by selecting appropriate macromolecules (for example, polyesters, polyamino acids, polyethylene glycol, polyvinyl pyrrolidone, ethylenevinyl- acetate, methylcellulose, carboxymethylcellulose, protamine sulfate, or lactide/glycolide copolymers). The rate of drug release may also be controlled by altering the concentration of such macromolecules. Another possible method for control¬ ling the duration of action comprises incorporating the therapeutic agents into particles of a polymeric substance such as polyesters, polyamino acids, hydrogels, poly- lactide/glycolide copolymers, or ethylenevinylacetate copoly- mers. Alternatively, it is possible to entrap the therapeutic agents in microcapsules prepared, for example, by coacervation techniques or by interfacial polymerization, for example, by the use of hydroxymethylcellulose or gelatin-microcapsules or pol (methyl ethacrolate) microcapsules, respectively, or in a colloid drug delivery system, for example, liposomes, albumin microspheres, * microemulsions, nanoparticles, nanocapsules, or in macroemulsions. ATHERO-ELAM, a soluble form of ATHERO-ELAM, a fragment of ATHERO-ELAM, or an antibody or antibody fragment directed to ATHERO-ELAM may be provided to a patient by means well known in the art. Such means of introduction include oral means, intranasal means, subcutaneous means, intramuscular means, intravenous means, intra-arterial means, or parenteral means. Having now generally described this invention, the same will be better understood with reference to certain specific examples which are included herein for purposes of illustra- tion only, and are not intended to be limiting of the inven¬ tion, unless specified. EXAMPLE 1 Isolation and Culture of Rabbit Endothelium Rabbit aorta (Ao) and inferior vena cava (IVC) endothelial cells (EC) were isolated with 0.2% or 0.4% collagenase (type I, Worthington Biochem. Corp.) respectively, from everted vessels (Cybulsky, M.I., et al . , FASEB J. 2:A1603 (1988); Danthuluri, N.R., et al .. Am. J. Phvsiol. 255 (Heart Cir. Phvsiol. 24):H1549-H1553 (1988)). EC were cultured on gelatin-coated tissue culture plastic in Medium 199 (Hank's salts) containing 20% fetal bovine serum (FBS), 10-20 μg/ml EC mitogen (Biomedical Technologies Inc.) and 20-40 μg/ml porcine intestinal heparin (Sigma, grade I). EC were subcultured with Trypsin/EDTA according to standard protocols. EXAMPLE 2 Isolation, Purification, Characterization and Labeling of Rabbit Leukocytes Rabbit leukocytes are isolated from blood obtained from the central ear artery of donor rabbits. Erythrocytes are sedimented with 1% hydroxyethyl cellulose and platelets are separated from the leukocyte-rich plasma by centrifugation. Leukocytes in the pellet are resuspended in HBSS without divalent cations with 1% human albumin USP (American Red Cross). Neutrophils (and eosinophils, which are dense cells) are separated from mononuclear leukocytes by density gravity centrifugation (Cybulsky, M.I., et al ., Am. J. Pathol. 125:1 (1986)). Their purity is assessed by Wright's-Giemsa staining of cytospins. Monocytes constitute 15-30% of mononuclear cells. They are larger than lymphocytes and are isolated by elutriation according to standard protocols (Doherty, D.E., et al .. Lab. Invest. 59:200 (1988)). The purity of monocyte preparations are assessed by nonspecific esterase staining (Yam, L.T., et al.. Amer. J. Clin. Pathol. 125:1 (1986)) of cytospins. A purity of 85-95% and recovery of 50-80% are achieved by this method. T lymphocytes (the predominant lymphocytes in blood) are purified by removing B lymphocytes using a panning procedure. This procedure involves adsorbing antibodies directed against rabbit immunoglobulins to plastic dishes and incubating elutriated lymphocytes for 1 hour at 4 β C. B lymphocytes, which express immunoglobulins on their surface, are bound by the adsorbed antibodies. Nonadherent T cells are collected and their purity assessed by immunostaining with a MAb to rabbit T cells (Lll/135, from ATCC) . A nylon wool purification step (Julius, M.H., et al . , Eur. J. Immunol. 3:645 (1973)) is utilized if necessary. Rabbit leukocytes are labeled by the fluorescent pH indicatory probe BCECF (Molecular probes). Cells suspended at 10 /ml are incubated in a protein-containing buffer for 15-30 minutes (37 β C) with BCECF/AM (10-20 μM) . The acetoxymethyl ester form of BCECF is permeable to cells and once in the cytoplasm it is trapped after being hydrolysed by esterase enzymes. When * quantitating adherent BCECF-labeled leukocytes, the pH of the lysis buffer is adjusted to the optimum for BCECF fluorescence (pH 8.8). 51 Rabbit leukocytes are also labeled with Na 5 Cr0 Δ or 111 In according to standard protocols (Cybulsky, M.I., et al .. Am. J. Pathol. 125:1 (1986); Danpure, H.J., et al .. Brit. J. Radio!. 55:247 (1982)). EXAMPLE 3 In Vitro Adhesion Assays Quantitative microtiter plate adhesion assays are performed according to Luscinskas et al . (Luscinskas, F.W., et al., J. Immunol. 142:2257 (1989)). Briefly, BCECF-labeled U937 leukocytes cells suspended in RPMI+1% FBS (2xl0 5 cells/0.2 ml/well) are allowed to adhere to confluent EC monolayers (passage 2 or 3) for 10 minutes at 37"C, then wells are filled with buffer, plates sealed, inverted, and centri¬ fuged at 250xg for 5 minutes. Adherent leukocytes are solubilized with 0.1% SDS in 50mM Tris-HCl pH 8.8, fluorescence quantitated in an automated plate reader (Pandex, Baxter Healthcare Corp.), and the number of leukocytes adhered in each well calculated. The relatively short adhesion time (10 minutes) is chosen in order to focus on leukocyte adhesion, rather than their transmigration under the EC monolayer, which occurs with lengthy incubations. For adhesion inhibition assays, EC monolayers are preincubated for 30 minutes, 22"C, with saturating concentrations of MAb F(ab')2 fragments. The concentration of F(ab')2 fragments required for maximal surface binding is determined for each MAb in fluorescent immunoassays and will be in the approximate range of 10-25 μg/lOOμl/well . EXAMPLE 4 Monoclonal Antibody Techniques a) MAb Production (Immunizations, Fusions, Screening, Cloning): Mice are immunized with rabbit endothelium acti¬ vated with LPS or other appropriate stimuli. Hybridomas are produced by fusing spleen lymphocytes from immunized mice with NS-1 or P3X63^Ag8.653 murine myeloma cells using standard polyethylene glycol protocols (Kohler, G., et al . , Nature 256:495 (1975); Goding, J.W., Monoclonal Antibodies: Prin¬ ciples and Practice, 2nd ed., Academic Press, London (1986)). The fusion is plated into four 96 well microtiter plates and after approximately 2 weeks, the primary screen, a cell surface fluorescent immunoassay, is performed. This screen (see Example 5) identifies wells containing immunoglobulins which recognize LPS-upregulated antigens on rabbit endo¬ thelium, typically up to 15 wells per fusion. The hybridomas in these wells are cloned by the limiting dilution technique (Goding J.W., Monoclonal Antibodies: Principles and Practice, 2nd ed., Academic Press, London (1986) and then secondary screens are performed. These include adhesion blocking assays with U937 cells and immunohistochemical staining of aortas from cholesterol-fed of WHHL rabbits. b) Immunoglobulin production in ascites, purification and F(ab')2 production: Immunoglobulins are produced in murine ascites (lOOmg-lg quantities), purified by ammonium sulfate precipitation, followed by ABx (Baker) chromatography according to standard methods (Goding, J.W. ' , Monoclonal Antibodies: Principles and Practice, 2nd ed., Academic Press, London (1986); Nau, D.R., BioCromatographv 4:4 (1989)). Purified immunoglobulins are digested with pepsin to F(ab'2) fragments at the optimum enzyme concentration and pH (Lamoyi, E., et al .. J. Immunol. Methods 56:235 (1983); Parham, P., jL. Immunol. 131:2895 (1983)). EXAMPLE 5 Fluorescence Immunoassays Cell surface binding assays are performed at 4°C on viable confluent EC monolayers utilizing saturating concentra¬ tions of MAb supernatants, followed by fluorescein-conjugated F(ab'2) goat anti-murine IgG (Caltag Labs). Fluorescence levels are determined using an automated plate reader (Pandex) and specific MAb binding calculated by subtracting fluores¬ cence readings obtained with IgG, antibodies which do not bind to rabbit EC (approximately 50 relative fluorescence units). EXAMPLE 6 Biochemical Technioues a) Im unoprecipitations: EC proteins are biosyntheti- 35 35 cally labeled with S-L-cysteine and S-L-methionine for 5 hours (2-6 hours of LPS treatment) (Bevilacqua, M.P., et al .. Proc. Natl. Acad. Sci. USA: 84:9238 (1987)). Surface EC 125 proteins are labeled with I using a glucose oxidase/lactoperoxidase protocol (Hubbard, A.L., et al., h. Cell Biol. 64:438 (1975)). EC are lysed in lOOmM Tris-HCl (pH 7.4), 150mM NaCl , 5mM EDTA, ImM phenyl methysulfonyl fluoride and 0.3% CHAPS, and insoluble material is removed by centrifugation (12,000xg, 0.5 hours, 4 β C). In immunoprecipitations, EC lysates (approximately 5x10 cells in lOOμl lysate/lane) are incubated for 2-4 hours (4 β C) with lOOμl of MAb culture supernatant and subsequently for 2-4 hours with goat anti-murine IgG coupled to Sepharose-4B (Cappel). The Sepharose is pretreated with unlabeled lysates to diminish nonspecific adherence of labeled proteins. Lysates of biosynthetically labeled EC, also, are precleared with a nonbinding MAb. Antigens specifically bound to Sepharose beads are extensively washed, and subjected to reduced SDS-PAGE analysis on 5-12% linear gradient gels (Laemmli, U.K., Nature 227:680 (1970)). b) Radioiodination of Proteins: F(ab'2) fragments are iodinated by the lactoperoxidase method (Marchalonis, J.J., Biochem. J. 113:299 (1969)). Following iodination and removal of free iodine by gel filtration chromatography, their ability to bind to an endothelial target is compared to an aliquot which was not iodinated. Alternative labeling protocols, for example, the Bolton-Hunter method (Bolton, A.E., et al ., Biochem. J. 133:529 (1973)), may also be used. EXAMPLE 7 Morphologic Techniques a) I munohistochemistry: Immunoperoxidase staining is performed on 4-6 μm frozen sections, fixed at -20 β C for 5 minutes in acetone or 1:1 * acetone:methanol . Sections are incubated (22 β C) in succession with MAb (2 hours), biotinylated horse anti-murine IgG (1 hour) and avidin-biotin peroxidase complexes (45 minutes) (Vector Labs). Peroxidase is visualized with 3-amino-9-ethylcarbazole (Sigma) and sections counterstained with Gill's hematoxylin. b) Staining with Oil Red 0: Lipids in aortic tissues are stained with oil red 0, an inert oil-soluble bis-azo dye, according to Adams and Bayliss (Adams, C.W.M., et al ., in Techniques of Biochemical and Biophysical Morphology. Vol . 2, Glick, D., et al . (eds.), Wiley, New York, p. 99 (1975)). After rinsing aortas with 70% isopropyl alcohol, they are stained for 30 minutes with a filtered saturated solution of oil red 0 in 60% isopropyl alcohol, then briefly rinsed with alcohol and rehydrated. c) Staining with Silver Nitrate: Interendothelial regions of aortic segments are stained with silver nitrate according to the protocol of Poole et al . (Poole, J.C.F., et al., J. Pathol. Bacteriol. 75:133 (1958)). d) Scanning Electron Microscopy: Aortas are perfused with Hanks balanced salt solution, to remove blood, then perfusion-fixed in situ under physiologic pressure (100mm Hg, 15 minutes) with buffered 2.5% glutaraldehyde. After harvesting, dissection of adventitia, and further fixation, portions of aorta are dehydrated with ethanol, critically- point dried, mounted on aluminum stubs and sputter-coated using a gold target according to standard protocols. Specimens are viewed in a scanning electron microscope. EXAMPLE 8 Molecular Biologic Techniques a) Lambda gtll cDNA Library Construction: For oligo- mer-primed libraries, mRNA is purified by a second round of oligo(dT) chromatography. The mRNA is converted to double- stranded cDNA by the method of Okayama and Berg (Okayama, H., et al.. Mol. Cell Biol. 2:161 (1982)) as modified by Gubler and Hoffman (Gubler, U., et al .. Gene 25:263 (1983)). Briefly, single stranded mRNA is converted to a RNA-cDNA hybrid by reverse transcriptase using a random hexanucleotide primer or oligo(dT). Next, the RNA-cDNA hybrid is converted to double stranded cDNA with a combination of RNase H (to cleave the RNA) and DNA polymerase (to synthesize the second cDNA strand using the nicked RNA as primers). Incomplete synthesis of the second cDNA strand is repaired by E. coli DNA ligase. Double-stranded cDNA is then protected from digestion by methylation, converted to a blunt-ended form by T4 DNA polymerase, and EcoRI linkers added. After cutting linkers with EcoRI and size selecting, cDNA's are ligated into EcoRI- cut gtll procaryotic expression vector. b) Oligonucleotide Synthesis: Oligonucleotides are synthesized using standard phosphoramidite chemistry (cycles of detritylat«ion, addition, capping, oxidation and deprotec- tion) with a DNA synthesizer, such as, for example, Applied Biosystems Model 381A. c) Radio!abeling of Probes: Radiolabeling of cDNA probes is performed using the oligonucleotide labeling method of Feinberg and Vogelstein (Feinberg, A.P., et al .. Anal . Biochem. 132:6 (1983)). This method utilizes random hexade- oxyribonucleotides as primers for DNA polymerase I-catalyzed 32 DNA synthesis in the presence of P-labeled nucleotides. The cDNA probe, denatured cDNA templates denatured by boiling serves as a template. Oligonucleotide probes are labeled 32 using T4 polymerase kinase to specifically transfer P label from the gamma position of ATP to the 5' OH groups of oligo DNA (Sambrook, J., et al . , Molecular Cloning. A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York (1989)). d) Sequencing DNA: Sequencing is performed utilizing commercially available kits according to the Sanger method of dideoxy-mediated chain termination (Sanger, F., et al . , Proc. Natl. Acad. Sci. USA 21:5463 (1977)). SP6, T7 and oligo¬ nucleotide primers are utilized. e) Northern Blotting: Cytoplasmic RNA is isolated by sucrose sedimentation, proteinase K digestion and phenol/chloroform extraction (Sambrook, J., et al ., Molecular Cloning. A Laboratory Manual. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York (1989)). After spectro- photometric quantitation and analysis in inigels, RNA is electrophoresed on formaldehyde/agarose gels and transferred by capillary action to a nitrocellulose membrane. A radio- labeled probe is hybridized to membranes, washed, and bound radioactivity visualized by autoradiography (Sambrook, J., et al ., Molecular Cloning. A Laboratory Manual. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York (1989)). EXAMPLE 9 Inhibition of leukocyte binding to LPS-treated endo¬ thelium After LPS treatment, EC monolayers (passage 2) were washed, then preincubated for 30 minutes (37 * C or 4 β C) with saturating concentrations of F(ab')2 (5 μg/0.1 ml RPMI 1% FBS/microtiter well). BCECF-labeled leukocytes suspended in RPMI 1% RBS (2 x 10 5 /0.1 ml) were added at the appropriate temperature to each well. In 37 β C adhesion assays, leukocytes were incubated for 10 minutes under static conditions with endothelium, then wells were filled with buffer, sealed, the plates inverted and centrifuged (250 x g, 5 minutes). 4 β C adhesion assays were 30 minutes in duration and nonadherent leukocytes were removed by sealing and inverting the plates for 20 minutes. Leukocyte adhesion to F(ab')2-preincubated monolayers was compared to monolayers treated with control buffer (RPMI 1% FBS) and statistical significance was estab¬ lished using a paired T test (* = p<0.05). The means and standard deviations (triplicate measurements) are plotted (Figure 3). At 4 β C, Rbl/9 F(ab')2 significantly inhibited the adhesion of U937, HL60, and THP-1 cell lines, as well as centrifugally elutriated human blood monocytes and lympho¬ cytes (Figure 3, upper panel). U937 and HL60 adhesion was also inhibited in assays performed at 37 β C. Significant decreases in adhesion were not observed with Rb2/4 or Rb2/3 F(ab')2 (Figure 3, middle and lower panels) or with W6/32 F(ab')2, a MAb which recognizes the major histocompatibility antigen on the human leukocytes, but not on rabbit EC. Adhesion to unactivated rabbit endothelium was not signifi¬ cantly inhibited by any of the F(ab')2 fragments. PMN adhesion to LPS-activated endothelium was not inhibited by Rbl/9 F(ab')2 under any conditions. Taken together, these data indicate that Rbl/9 recognizes a leukocyte adhesion molecule which appears to be selective for mononuclear leukocytes. EXAMPLE 10 Immunohistochemical staining of rabbit aortas Immunohistochemical staining was performed on aortas from rabbits fed a hypercholesterolemic diet and from Watanabe heritable hyper!ipidemic (WHHL) rabbits. Specific staining with monoclonal antibody Rbl/9 was localized to endothelium covering foam-rich aortic intimal lesions, at various stages of their development. Frozen sections of the same atherosclerotic lesion located in the descending thoracic aortic from a rabbit fed a 1% cholesterol diet for 9 weeks are shown in Figure 4, A-D (arrowhead marks edge of lesion). In section A, the lesion was stained for smooth muscle cells with MAb CGA7 (directed to smooth muscle cell-specific alpha actin, 1/300 dil. of ascites, ENZ0 Biochem. Inc.). M = media, IL = intimal lesion, bar = 100 μm. In section B, the lesion was stained for rabbit macrophages with MAb RAM 11 (1/3000 dil. of ascites), bar = 100 μm. In sections C and D, the lesion was stained for ATHERO-ELAM with Rbl/9 (culture supernatant). ATHERO-ELAM expression was detected in EC overlying and immediately adjacent to the intimal lesion. EC in adjacent uninvolved aorta (UA) failed to stain with Rbl/9, but did stain with a constitutive EC marker (Figure 4, C inset, goat anti-human von Willebrand Factor, 1/3000 dil. of IgG, Atlantic Ab., bar = 50 μm). In adjacent sections, EC did not stain with a nonbinding, isotype matched MAb E1/C15 (D inset, culture supernatant, bar = 10 μm). FC = foam cells, IEL = internal elastic lamina, bars in Figure 4C and 4D represent 50 and 10 μm, respectively. Figure 4E shows Rbl/9 staining of £c overlying an intimal foam cell-rich lesion in the aortic arch of an 18-week WHHL rabbit (bar = 10 μm). Figure 4F shows focal ATHERO-ELAM expression associated with small foam cell aggregates in the descending thoracic aorta of a rabbit with dietary hypercholesterolemia (bar = 100 μm). Im unoperoxidase staining was performed on 4-6 μm frozen sections, fixed at -20 β C for 5 minutes in acetone, or 1:1 ace- tone:methanol (for CGA7 and RAMll). Sections were incubated (22 β C) in succession with MAb (2 hours), biotinylated horse anti-murine IgG (1 hour) and avidin-biotin peroxidase complexes (45 minutes) (Vector Labs.). Peroxidase was visualized with 3-amino-9-ethylcarbazole (Sigma) and sections were counterstained with Gill's hematoxylin. The MAb developed to rabbit EC, including Rbl/9, do not recognize epitopes on normal or activated human endothelium in culture or in tissue sections. EXAMPLE 11 Immunoprecipitation of polypeptides with MAb Rbl/9 EC proteins were biosynthetically labeled with ^^S-L- cysteine and 35 S-L-methionine for 5 hours (2nd to 7th hour of LPS treatment (Luscinskas, F.W., et al . , J. Immunol. 142:2257 (1989); Bevilacqua, M.P., et al .. Proc. Nat! . Acad. Sci. USA 84:9238 (1987); Smith, C.W., et al.. J. Clin. Invest. 82:1746 (1988)). Surface EC proteins were labeled with 125 I using a glucose oxidase/lactoperoxidase protocol (Hubbard, A.L., et al.. J. Cell. Biol. 64:438 (1975)). EC were lysed in 100 mM Tris-HCl (pH 7.4), 150 mM NaCl, 5 mM EDTA, 1 mM phenylmethylsulfonyl fluoride and 0.3% CHAPS, and insoluble material was removed by centrifugation (12,000 x g, 0.5 hour, 4 β C). In immunoprecipitations, EC lysates (approximately 5 x 10^ cells in 100 μl lysate/lane) were incubated for 2-4 hours (4 β C) with 100 μl of MAb culture supernatant and subsequently for 2-4 hours with goat anti- murine IgG coupled to Sepharose-4B (Cappel), which was pretreated with unlabeled lysates to diminish nonspecific adherence of labeled proteins. Lysates of biosynthetically labeled EC, also, were precleared with a nonbinding MAb. Antigens specifically bound to Sepharose beads were exten- sively washed, and subjected to reduced SDS-PAGE analysis on 5-12% linear gradient gels (Laemmli, U.K., Nature 227:680 (1970)). Immunoprecipitation with MAb Rbl/9 and Rb2/4 showed reciprocal specific depletion of antigen. In contrast, two successive immunoprecipitations with MAb Rb2/3 did not deplete the polypeptides recognized by Rbl/9 and Rb2/4 (Figure 5B). N-terminal amino acid sequence derived from the purified 98K polypeptide (ATHERO-ELAM) showed 20 of 22 amino acid homology (Sequence ID 2, amino acids 1-22) to the predicted N- terminal sequence of human VCAM-1 (Sequence ID 7, amino acids 1-22) (Figure 6). N-terminal sequences of the 118K and 98K polypeptides were identical and in Western blots both polypeptides were recognized by MAb Rbl/9, suggesting that both are products of the same gene. The polypeptides were purified by Rbl/9 immunoaffinity chromatography (Affi-Gel Hz, Bio Rad) and SDS-PAGE from cell membrane preparations obtained from lungs of 10 rabbits sacrificed 4 hours after an intravenous LPS injection (100 μg/kg). After SDS-PAGE, the polypeptides were electrotransferred (25 mM Tris, 192 mM Glycine, pH 8.3, 20% methanol buffer, 100V, x 100 minutes, 4 β C) to an Immobilon-P membrane (Millipore Corp.), and N-terminal amino acid sequences obtained from excised Coomassie Brilliant Blue- stained bands, by phenyl isothiocyanate degradation cycles using an automated gas phase sequencer (Applied Biosystems) (LeGendre, N., et al . , in A Practical Guide to Protein and Peptide Purification for Microseouencing, Matsudaira, P. (ed.), Academic 1 Press, San Diego, p. 49 (1989)). Figure 5A shows biosynthetically labeled cells (left panel, [-] = control EC, [+] = LPS-activated), and surface- iodinated LPS-activated cells (right panel). MAb Hu5/3 and E1/C15 (IgG j ) bind to human, but not rabbit, EC and did not specifically precipitate polypeptides. EXAMPLE 12 Cell and monoclonal antibody binding to EC monolayers Quantitative adhesion assays were performed in microtiter plates. U937 cells labeled with BCECF and suspended in RPMI 1% RBS (2 x 10 5 cells/0.2 ml/well) were allowed to adhere to EC monolayers for 10 minutes at 37 β C, then wells were filled with buffer, plates sealed, inverted, and centrifuged (250 x g, 5 minutes, 22 β C) (Luscinskas, F.W., et al., J. Immunol. 142:2257 (1989); Bevilacqua, M.P., et al.. Proc. Nat! . Acad. Sci. USA 84:9238 (1987); Smith, C.W., et al.. J. Clin. Invest. 82:1746 (1988)). MAb were generated by fusing NS-1 myeloma cells with spleen cells from mice immunized with 5 hour LPS-treated IVC EC according to standard protocols. Cell surface binding assays were performed at 4 β C on viable EC monolayers, utilizing saturating concentrations of MAb supernatants and fluorescein-conjugated F(ab') goat anti-murine IgG (Caltag Labs). Fluorescence levels were determined using an automated plate reader (Pandex, Baxter Healthcare Corp.) and specific MAb binding was determined by subtracting fluorescence readings obtained with IgG j antibodies which do not bind to rabbit EC (approximately 50 relative fluorescence units). Figure 1 illustrates U937 adhesion (A & B) and specific MAb binding (C & D) to EC monolayers (passage 2), derived from the aorta (Ao) and inferior vena cava (IVC) of the same New Zealand White rabbit. Activation of EC with LPS (E. coli, 1 μg/ml) increased both U937 adhesion (A) and MAb binding (C) in a time-dependent fashion. Cycloheximide (CHX, 10 μg/ml; solid bars) coincubation, during LPS treatment (5 hour) of IVC EC, abolished the LPS-induced increase in U937 adhesion (B) and RBI/9 cell surface binding (D) . CHX did not affect the integrity of EC monolayers, or the binding of MAb Rb2/13 to an abundant constitutive EC antigen, whose expression was not altered by LPS (D insert). In each graph the data points represent the means and standard deviations of quadruplicate measurements. EXAMPLE 13 Production of Soluble ATHERO-ELAM Soluble transmembrane proteins can be produced by genetically engineering a cDNA containing a termination codon immediately 5' of the transmembrane domain. When expressed in appropriate cells, the protein synthesized from this cDNA is secreted, and can be recovered from the culture Production of soluble ATHERO-ELAM from Rabbit Endothelium Using the Polymerase Chain Reaction: Rabbit endothelial cells are treated with lμg/ml of LPS for 4-8 hours at 37 β C; cytoplasmic RNA is prepared by a detergent lysis protocol (Sambrook, J., et al ., Molecular Cloning, A Laboratory Manual, 2nd ed. Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, (1989)). First strand cDNA is synthesized during a 1 hour incubation (42 β C, final reaction volume of 40 μl), using 1 μg of RNA as template, 50 ng of an appropriate oligonucleotide primer complementary to a sequence found in the 3' untranslated region of ATHERO-ELAM mRNA and 100U of avian myeloblastosis virus reverse transcriptase (Molecular Genetic Resources, Tampa, FL). Two rounds of PCR are performed utilizing nested primers, and 5 μl of first strand cDNA or first round PCR products as templates (Sailα, R.K., et al.. Science 239:1350 (1988)). For the first round of PCR, 300 ng of primers are used. The 5' primer corresponds to a region 5' to the open reading frame (5' untranslated region), and the 3' primer is the same as was used for cDNA synthesis. For the second round of PCR, 150 ng of primers are used. The 5' primer still corresponds to the 5' untranslated region, but is 3' to the primer used for the first round of PCR. The 3' primer is complementary to a region immediately 5' of the transmembrane domain and contains an in frame termination codon (e.g., TAA). Primers may have genetically engineered convenient restriction enzyme sites for subcloning purposes. Preferably, both " rounds of PCR are 26 cycles performed under appropriate conditions: for example, one minute of denaturing at 94 β C, two minutes of annealing at 50 * C, and 6 minutes of extension at 72'C with a 40 minute extension time in the first cycle. PCR products are then analyzed by standard agarose gel electrophoresis and Southern blotting. The prominent reaction product from a parallel set of 6 PCR reaction tubes is then pooled and purified. The ends of the PCR product are repaired with the Klenow fragment of DNA polymerase I, phosphorylated with T4 kinase, and the fragment subcloned into the Hindi site of the plasmid vector pBS (Stratagene, La Jolla, CA). Subsequently, purified plasmid DNA is cut with appropriate restriction enzymes and the ATHERO-ELAM cDNA insert subcloned into an appropriate eukaryotic expression vector, for example, pcDNA-I (Invitrogen, San Diego, CA). This construct is transfected into appropriate cells, for example, COS cells. EXAMPLE 14 Cloning and Sequencing of the Human VCAM-1 Gene A bacteriophage lambda library of human peripheral blood DNA in the vecfor EMBL3 (Bonthron, D.T., et al., Proc. Nat! . Acad. Sci. USA 85:1492-1496 (1988)) was plated, nitrocellulose filters prepared according to standard procedures (Sambrook, J., et al .. Molecular Cloning, A Laboratory Manual. 2nd edition, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (1989)), and screened with a rabbit partial cDNA for VCAM- 1. The cDNA probe was labeled with Klenow fragment of DNA polymerase I in the presence of hexanucleotide primers and [alpha- 32 PJ dCTP (Feinberg, A.P., et al . , Anal. Biochem. 131:6-13 (1983)). Filters were incubated with the radiolabeled probe in 6XSSC, 0.5% SDS at 65 β C, and washed with 0.5XSSC, 0.5% SDS at 65 * C. Hybridizing bacteriophage were purified and amplified, bacteriophage DNA prepared, and restriction fragments containing the VCAM-1 gene ligated into the plasmid vector pBS (Sambrook, J., et al . , Molecular Cloning, A Laboratory Manual, 2nd edition, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (1989)). Nucl eoti de sequences were determi ned by the dideoxynucleotide chain termination procedure with modified T7 DNA polymerase (United States Biochemical Corp. , Cleveland, Ohio) and [alpha- 35 S] -dATP. Ol igonucleotide primers were synthesized using an ol igonucleotide synthesizer (Appl ied Bi osystems, Foster City, CA) and were used without purification. EXAMPLE 15 Production of a Seven Immunoglobulin Domain Soluble Human VCAM-1 Subculture 2 human umbilical vein endothelial cells (HUVEC) isolated from two to six umbilical cords (Bevilacqua M.P., et al.. Science 243:1160-1165 (1989)) were treated with lOU/ml of recombinant human IL-1 beta (Biogen, Boston, MA) for 6 hours at 37 β C; cytoplasmic RNA was prepared by a detergent lysis protocol (Sambrook, J., et al .. Molecular Cloning, A Laboratory Manual , 2nd edition, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (1989)). First strand cDNA was synthesized during a 1 hour incubation (42°C, with a final reaction volume of 40 μl), using 1 μg of RNA as template, 50 ng of an oligonucleotide primer complementary to the sequence found in the 3' untranslated region of VCAM-1 mRNA- GGGTCATATAGTCTTGTAGAAGCACAGAAATC (Sequence ID 10) and 100U of avian myeloblastosis virus reverse transcriptase (Molecular Genetic Resources, Tampa, FL). Two rounds of PCR were performed utilizing nested primers, and 5 μl of first strand cDNA or first round PCR products as templates (Salki, R.K., et al . , Science 239:487- 491 (1988)). 300 ng of primers were used for the first round of PCR and 150 ng for the second round. A primer to the 5' untranslated region of the mRNA-GAGCTGAATACCCTCCCAGGCACACACA- GGTG (Sequence ID 11) and the same 3' primer as was used in cDNA synthesis were used for first round PCR. The nested set of primers consisted of GGGTTTTGGAACCACTATTTTGTCATC (Sequence ID 12) and a sequence complementary to GTTTAACACTTGATGTTCAAGG- AAGAGAAAACTAA (Sequence ID 13). The latter primer encodes a termination codon (TAA) immediately 5' of the VCAM-1 transmembrane domain. Both rounds of PCR were 26 cycles performed under the following conditions: one minute of denaturing at 94 β C, two minutes of annealing at 50 * C, and 6 minutes of extension at 72 β C with a 40 minute extension time in the first cycle. PCR products (10 μl) were analyzed by standard agarose gel electrophoresis and Southern blotting (Sambrook, J., et al., Molecular Cloning. A Laboratory Manual, 2nd edition, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (1989)). The prominent 2.05 kb reaction product from a parallel set of 6 PCR reaction tubes was pooled and purified. The ends of the PCR product were repaired with the Klenow fragment of DNA polymerase I, phosphorylated with T4 kinase, and the fragment was subcloned into the Hindi site of the plasmid vector pBS (Stratagene, La Jolla, CA), according to standard procedures (Sambrook, J., et al . , Molecular Cloning, A Laboratory Manual , 2nd edition, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (1989)). The PCR insert was subcloned into pcDNA-I (Invitrogen, San Diego, CA) and expressed in COS cells. It will be appreciated by those skilled in the art that various modifications can be made to the above described embodiments of the invention without departing from the essential nature thereof. It is intended to encompass all such modifications within the scope of the appended claims. SEQUENCE LISTING (1) GENERAL INFORMATION: (i) APPLICANT: Cybulsky, Myron I. Gimbrone, Michael A. Col1ins, Tucker (ϋ) TITLE OF INVENTION: Mononuclear Leukocyte Directed Endothelial Adhesion Molecule Associated with Atherosclerosis (iϋ) NUMBER OF SEQUENCES: 13 (iv) CORRESPONDENCE ADDRESS: (A) 'ADDRESSEE: Sterne, Kessler, Goldstein & Fox (B) STREET: 1225 Connecticut Avenue, N.W. Suite 300 (C) CITY: Washington (D) STATE: District of Columbia (E) COUNTRY: United States of America (F) ZIP: 20036 (v) COMPUTER READABLE FORM: (A) MEDIUM TYPE: Floppy Disk (B) COMPUTER: IBM PC compatible (C) OPERATING SYSTEM: PC-DOS/MS-DOS (D) SOFTWARE: Ascii (vi) CURRENT APPLICATION DATA: (A) APPLICATION NUMBER: to be determined (B) FILING DATE: filing herewith (C) CLASSIFICATION: to be determined (vii) PRIOR APPLICATION DATA: (A) APPLICATION NUMBER: U.S. 07/487,038 (B) FILING DATE: 02-MAR-1990 (Vlll) ATTORNEY INFORMATION: (A) NAME: Potter, Jane E. R. (B) REGISTRATION NUMBER: 33,332 (C) REFERENCE/DOCKET NUMBER: 0627.2100004 (viii) TELECOMMUNICATION INFORMATION: (A) TELEPHONE: (202) 833-7533 (2) INFORMATION FOR SEQ ID NO:l: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 2487 base pairs (B) TYPE: nucleic Acid (D) TOPOLOGY: linear (ii) MOLECULAR TYPE: DNA (Xi) SEQUENCE DESCRIPTION: SEQ ID No:l: ATGCCTGGGA AGATGGTCCT GGTCTTTGGA GTCTCAACTC TACTTTGGAT 50 GATGATTGCA GCTTCTCAAG CTTTTAAAAT TGAGACCTTC CCCGAATCCA 100 GATCTCTTGC TCAAATTGGT GACTCTGTCT CATTGACTTG CACCACCATG 150 GGCTGTGCAT CCCCAACATT CTCTTGGAGA ACCCAGATAG ACAGCCCACT 200 GAATGGGAAG GTGAGGAGCG AGGGGACCAC GTCCACATTG ACCATGGATC 250 CTGTGAGTTT CGAGAACGAA CACTCTTACC TGTGTACAGC GACTTGTGAA 300 TCCAAGAAAC TGGAAAAAGG AGTTCAGGTG GAAATCTACT CATTCCCCAA 350 GGATCCAGAG ATTCATTTGA GTGGCCCTTT GGAGGTTGGA GAACCAATCA 400 CAGTCAAGTG TTTGGTCCCT GATGTATACC CGTTTGATAG GCTAGAAGTG 450 GATTTACTGA AAGGTGACTA CCTCATGAAG AAACAGGACT TTCTGGAAGA 500 CATGGACAGG AAGTCCTTGG AAACCAAGAG TTTGGAAGTA ACCTTTATTC 550 CAGTCATTGA AGATATTGGA AAACTTATTG TTTGCCGAGC TAAATTACAT 600 ATCGATGAAA TTGATTCTGA ACCCAAAGAA AGAGAGACCA CCAAAGAACT 650 ACAGGTCTAC ATTTCACCCA AGAATACAGT TATCTCTGTG AATCCCTCCA 700 CAAGGCTGCA AGAAGGTGGC TCTGTGACAA TGACATGTTC CAGCGAGGGT 750 CTACCAGTTC CAGAGATTTT CTGGAGTAAG AAACAAGATA ATGGGAATCT 800 ACAGCGCCTT TCTGGGAATG CAACTCTCAC ATTAATTGCT ATGAGGATGG 850 AAGATTCTGG AATTTATGTG TGTGAAGGAG TTAATCAGAT TGGGAAAAGC 900 AGAAAAGAGG TGGAATTAAT AGTTCAAGAG AAACCATTTA CCGTTGAGAT 950 CTCCCCTGGA CCCAGGATTG CTGCTCAGAT TGGGGACCCA GTTGTATTGA 1000 CATGTAGTGT CAGGGGCTGT GAGACCCCAT CTTTCTCTTG GAGAACCCAG 1050 ATAGATAGCC CTCTGAATGG GCAGGTGACA AGTGAAGGGA CCAAGTCTTT 1100 GCTAACATTG AGTCCTGTGA GTTTTGAGAA CGAACATTCT TACCTATGTA 1150 CCGTGACCTG TGGACATAAG AAACTGGAAA AGGGAATTCA GGTGGAGCTC 1200 TACTCATTCC CTAGAGATCC AGAAATTGAG CTGAGCGGTC CACCAGTGAA 1250 TGGGCGCCCT GTCACTGTCA GCTGCAAAGT TCCTAATGTG TACCCTTTTG 1300 ACCGGTTGGA GATTGAATTA CTTAAGGGAG AGACCATGAT GAAGAATAAA 1350 GAATTTTTGG AGGAAGAGGA TAAGAAATCC CTAGAGACCA AAAGTTTAGA 1400 AATGACCTTC ATCCCCACCA TGGAAGACAC TGGCAAAGTT CTTGTTTGTC 1450 AGGCCAAGTT ACATATTGAT GAAATGGAAT TTGAACCCAA ACAAAGGCAG 1500 AGTACACAAC CACTTTTTGT CAATGTTGCC CCCAGGGATA TAGCTGTCTG 1550 GGTCAGTCCC TCGTCCATCG TGGAGGAAGG CCGTTCTGTG AATATGACGT 1600 GCTCTAGTTA TGGCCTTCCA GCTCCAAAAA TCCTGTGGAG CAGACAACTG 1650 AAAAATGGGG ACCTACAGCC TCTTTCAGAA AATACAACTT TAGCCTTAAT 1700 TTCTACAAAA CTGGAAGATT CTGGTATTTA CGTGTGTGAA GGGATTAACC 1750 TGGCTGGAAA GAGCAGAAAA GAAGTTGAAT TAGTTATCCA AGTTGCTCCA 1800 AAAGATATAC AACTGACGGC TTTTCCTTCT AAGAGTGTCA AAGAAGGAGA 1850 CACTGTCATT ATTTCCTGTA CTTGTGGGAA TGTTCCTGAA ACTTGGATAA 1900 TTCTGAAGAA AAAAGCGGAG ACAGGAGACA CAGTGCTAAA GTCTATAGAT 1950 GGTGCATATA CCATTCGTAA GGCCCAGCTG GAGGATGCAG GAGTGTATGA 2000 ATGTGAATCT AAAAATGAGG TTGGCTCACA ATTAAGAAGT ATAACACTTG 2050 ATGTTAAAGT ACCTCCTCGA AACACGACAA TATCAATACA TCCATCTAGC 2100 AATGTTAAAG AAGGGGAAAA TATCACAATT ACATGTAAAA CTTTTAGTCA 2150 TCCCCCTGCA GTGATTATCC TGAAAAGAGT TGATCTTGCC AATGAAATTA 2200 CTATGTGTTC AAAGAATGGA ACATTTACCT TATACCATGT CACTCAAAGT 2250 GATACAGGGG TATATGTAAT CAGAGCTTCC AATGAGGTTG GGGATGATTC 2300 TGGACGGATT GAGATCTCAG TTATGAGAAG AGAAAATAGC AAGGACTATT 2350 TTTCTCCTGA ACTTCTCGTG CTCTATTGTG CATCCTCCTT AATAATACCT 2400 GCCATCGGAA TGATCATTTA CTTTGCAAGA AAAGCCAACA TGAAAGGATC 2450 ACACAGTCTG GTAGAAGCAC AGAAATCAAA AGTGTAG 2487 (2) INFORMATION FOR SEQ ID NO:2: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 828 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULAR TYPE: peptide ( i) SEQUENCE DESCRIPTION: SEQ ID NO:2: Met Pro Gly Lys Met Val Leu Val Phe Gly Val Ser Thr Leu Leu Trp 1 5 10 15 Met Met lie Ala Ala Ser Gin Ala Phe Lys lie Glu Thr Phe Pro Glu 20 * 25 30 Ser Arg Ser Leu Ala Gin lie Gly Asp Ser Val Ser Leu Thr Cys Thr 35 40 45 Thr Met Gly Cys Ala Ser Pro Thr Phe Ser Trp Arg Thr Gin lie Asp 50 55 60 Ser Pro Leu Asn Gly Lys Val Arg Ser Glu Gly Thr Thr Ser Thr Leu 5 70 75 80 Thr Met Asp Pro Val Ser Phe Glu Asn Glu His Ser Tyr Leu Cys Thr 85 90 95 Ala Thr Cys Glu Ser Lys Lys Leu Glu Lys Gly Val Gin Val Glu lie 100 105 110 Tyr Ser Phe Pro Lys Asp Pro Glu lie His Leu Ser Gly Pro Leu Glu 115 120 125 Val Gly Glu Pro lie Thr Val Lys Cys Leu Val Pro Asp Val Tyr Pro 130 135 140 Phe Asp Arg Leu Glu Val Asp Leu Leu Lys Gly Asp Tyr Leu Met Lys 145 150 155 160 Lys Gin Asp Phe Leu Glu Asp Met Asp Arg Lys Ser Leu Glu Thr Lys 165 170 175 Ser Leu Glu Val Thr Phe lie Pro Val lie Glu Asp lie Gly Lys Leu 180 185 190 lie Val Cys Arg Ala Lys Leu His lie Asp Glu lie Asp Ser Glu Pro 195 200 205 Lys Glu Arg Glu Thr Thr Lys Glu Leu Gin Val Tyr lie Ser Pro Lys 210 215 220 Asn Thr Val lie Ser Val Asn Pro Ser Thr Arg Leu Gin Glu Gly Gly 225 230 235 240 Ser Val Thr Met Thr Cys Ser Ser Glu Gly Leu Pro Val Pro Glu lie 245 250 255 Phe Trp Ser Lys Lys Gin Asp Asn Gly Asn Leu Gin Arg Leu Ser Gly 260 265 270 Asn Ala Thr Leu Thr Leu lie Ala Met Arg Met Glu Asp Ser Gly lie 275 280 285 Tyr Val Cys Glu Gly Val Asn Gin lie Gly Lys Ser Arg Lys Glu Val 290 295 300 Glu Leu lie Val Gin Glu Lys Pro Phe Thr Val Glu He Ser Pro Gly 305 310 315 320 Pro Arg He Ala Ala Gin He Gly Asp Pro Val Val Leu Thr Cys Ser 325 330 335 Val Arg Gly Cys Glu Thr Pro Ser Phe Ser Trp Arg Thr Gin He Asp 340 345 350 Ser Pro Leu Asn Gly Gin Val Thr Ser Glu Gly Thr Lys Ser Leu Leu 355 360 365 Thr Leu Ser Pro Val Ser Phe Glu Asn Glu His Ser Tyr Leu Cys Thr 370 375 380 Val Thr Cys Gly His Lys Lys Leu Glu Lys Gly He Gin Val Glu Leu 385 390 395 400 Tyr Ser Phe Pro Arg Asp Pro Glu He Glu Leu Ser Gly Pro Pro Val 405 410 415 Asn Gly Arg Pro Val Thr Val Ser Cys Lys Val Pro Asn Val Tyr Pro 420 425 430 Phe Asp Arg Leu Glu He Glu Leu Leu Lys Gly Glu Thr Met Met Lys 435 440 445 Asn Lys Glu Phe Leu Glu Glu Glu Asp Lys Lys Ser Leu Glu Thr Lys 450 455 460 Ser Leu Glu Met Thr Phe He Pro Thr Met Glu Asp Thr Gly Lys Val 465 470 475 ' 480 Leu Val Cys Gin Ala Lys Leu His He Asp Glu Met Glu Phe Glu Pro 485 490 495 Lys Gin Arg Gin Ser Thr Gin Pro Leu Phe Val Asn Val Ala Pro Arg 500 505 510 Asp He Ala Val Trp Val Ser Pro Ser Ser He Val Glu Glu Gly Arg 515 520 525 Ser Val Asn Met Thr Cys Ser Ser Tyr Gly Leu Pro Ala Pro Lys He 530 535 540 Leu Trp Ser Arg Gin Leu Lys Asn Gly Asp Leu Gin Pro Leu Ser Glu 545 550 555 560 Asn Thr Thr Leu Ala Leu He Ser Thr Lys Leu Glu Asp Ser Gly He 565 570 575 Tyr Val Cys Glu Gly He Asn Leu Ala Gly Lys Ser Arg Lys Glu Val 580 585 590 Glu Leu Val He din Val Ala Pro Lys Asp He Gin Leu Thr Ala Phe 595 600 605 Pro Ser Lys Ser Val Lys Glu Gly Asp Thr Val He He Ser Cys Thr 610 615 620 Cys Gly Asn Val Pro Glu Thr Trp He He Leu Lys Lys Lys Ala Glu 625 630 635 640 Thr Gly Asp Thr Val Leu Lys Ser He Asp Gly Ala Tyr Thr He Arg 645 650 655 Lys Ala Gin Leu Glu Asp Ala Gly Val Tyr Glu Cys Glu Ser Lys Asn 660 665 670 Glu Val Gly Ser Gin Leu Arg Ser He Thr Leu Asp Val Lys Val Pro 675 680 685 Pro Arg Asn Thr Thr He Ser He His Pro Ser Ser Asn Val Lys Glu 690 695 700 Gly Glu Asn He Thr He Thr Cys Lys Thr Phe Ser His Pro Pro Ala 705 710 715 720 Val He He Leu Lys Arg Val Asp Leu Ala Asn Glu He Thr Met Cys 725 730 735 Ser Lys Asn Gly Thr Phe Thr Leu Tyr His Val Thr Gin Ser Asp Thr 740 745 750 Gly Val Tyr Val He Arg Ala Ser Asn Glu Val Gly Asp Asp Ser Gly 755 760 765 Arg He Glu He Ser Val Met Arg Arg Glu Asn Ser Lys Asp Tyr Phe 770 775 780 Ser Pro Glu Leu Leu Val Leu Tyr Cys Ala Ser Ser Leu He He Pro 785 790 795 800 Ala lie Gly Met He He Tyr Phe Ala Arg Lys Ala Asn Met Lys Gly 805 810 815 Ser His Ser Leu Val Glu Ala Gin Lys Ser Lys Val 820 825 (2) INFORMATION FOR SEQ ID NO:3: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 276 base pairs (B) TYPE: nucleic acid (D) TOPOLOGY: linear (ii) MOLECULAR TYPE: DNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3: AGAAACCATT TACTGTTGAG ATCTCCCCTG GACCCCGGAT TGCTGCTCAG 50 ATTGGAGACT CAGTCATGTT GACATGTAGT GTCATGGGCT GTGAATCCCC 100 ATCTTTCTCC TGGAGAACCC AGATAGACAG CCCTCTGAGC GGGAAGGTGA 150 GGAGTGAGGG GACCAATTCC ACGCTGACCC TGAGCCCTGT GAGTTTTGAG 200 AACGAACACT CTTATCTGTG CACAGTGACT TGTGGACATA AGAAACTGGA 250 AAAGGGAATC CAGGTGGAGC TCTACT 276 (2) INFORMATION FOR SEQ ID NO:4: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 92 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULAR TYPE: peptide (ix) FEATURE: Sequence ID No. 4 represents amino acids 310-4 of Sequence ID No. 2. ( i) SEQUENCE DESCRIPTION: SEQ ID NO:4: Glu Lys Pro Phe Thr Val Glu He Ser Pro Gly Pro Arg He Ala Ala 1 5 10 15 Gin He Gly Asp Pro Val Val Leu Thr Cys Ser Val Arg Gly Cys Glu 20 25 30 Thr Pro Ser Phe Ser Trp Arg Thr Gin He Asp Ser Pro Leu Asn Gly Gin Val Thr Ser Glu Gly Thr Lys Ser Leu Leu Thr Leu Ser Pro Val 50 55 60 Ser Phe Glu Asn Glu His Ser Tyr Leu Cys Thr Val Thr Cys Gly His 65 70 75 80 Lys Lys Leu Glu Lys Gly He Gin Val Glu Leu Tyr 85 90 (2) INFORMATION FOR SEQ ID NO:5: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 92 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULAR TYPE: peptide (ix) FEATURE: Sequence ID No. 5 represents amino acids 286- of Sequence ID No. 7. (Xi) SEQUENCE DESCRIPTION: SEQ ID NO:5: Glu Lys Pro Phe Thr Val Glu He Ser Pro Gly Pro Arg He Ala Ala 1 5 10 15 Gin He Gly Asp Ser Val Met Leu Thr Cys Ser Val Met Gly Cys Glu 20 25 30 Ser Pro Ser Phe Ser Trp Arg Thr Gin He Asp Ser Pro Leu Ser Gly 35 40 45 Lys Val Arg Ser Glu Gly Thr Asn Ser Thr Leu Thr Leu Ser Pro Val 50 55 60 Ser Phe Glu Asn Glu His Ser Tyr Leu Cys Thr Val Thr Cys Gly His 65 70 75 80 Lys Lys Leu Glu Lys Gly He Gin Val Glu Leu Tyr 85 90 (2) INFORMATION FOR SEQ ID NO:6: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 276 base pairs (B) TYPE: nucleic Acid (D) TOPOLOGY: linear (ii) MOLECULAR TYPE: DNA (ix) FEATURE: Sequence ID No. 6 represents nucleotides 929-1 of Sequence ID No. 1. (xi) SEQUENCE DESCRIPTION: SEQ ID NO:6: AGAAACCATT TACCGTTGAG ATCTCCCCTG GACCCAGGAT TGCTGCTCAG 50 ATTGGGGACC CAGTTGTATT GACATGTAGT GTCAGGGGCT GTGAGACCCC 100 ATCTTTCTCT TGGAGAACCC AGATAGATAG CCCTCTGAAT GGGCAGGTGA 150 CAAGTGAAGG GACCAAGTCT TTGCTAACAT TGAGTCCTGT GAGTTTTGAG 200 AACGAACATT CTTACCTATG TACCGTGACC TGTGGACATA AGAAACTGGA 250 AAAGGGAATT CAGGTGGAGC TCTACT 276 (2) INFORMATION FOR SEQ ID NO:7: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 662 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULAR TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO:7: Phe Lys He Glu Thr Thr Pro Glu Ser Arg Tyr Leu Ala Gin He Gly 1 5 10 15 Asp Ser Val Ser Leu Thr Cys Ser Thr Thr Gly Cys Glu Ser Pro Phe 20 25 30 Phe Ser Trp Arg Thr Gin He Asp Ser Pro Leu Asn Gly Lys Val Thr 35 40 45 Asn Glu Gly Thr Thr Ser Thr Leu Thr Met Asn Pro Val Ser Phe Gly 50 55 60 Asn Glu His Ser Tyr Leu Cys Thr Ala Thr Cys Glu Ser Arg Lys Leu 65 70 75 80 Glu Lys Gly He Gin Val Glu He Tyr Ser Phe Pro Lys Asp Pro Glu 85 90 95 He His Leu Ser Gly Pro Leu Glu Ala Gly Lys Pro He Thr Val Lys 100 105 110 Cys Ser Val Ala Asp Val Tyr Pro Phe Asp Arg Leu Glu He Asp Leu 115 120 125 Leu Lys Gly Asp His Leu Met Lys Ser Gin Glu Phe Leu Glu Asp Ala 130 135 ■ 140 Asp Arg Lys Ser Leu Glu Thr Lys Ser Leu Glu Val Thr Phe Thr Pro 145 150 155 160 Val He Glu Asp He Gly Lys Val Leu Val Cys Arg Ala Lys Leu His 165 170 175 He Asp Glu Met Asp Ser Val Pro Thr Val Arg Gin Ala Val Lys Glu 180 185 190 t Leu Gin Val Tyr He Ser Pro Lys Asn Thr Val He Ser Val Asn Pro 195 200 205 Ser Thr Lys Leu Gin Glu Gly Gly Ser Val Thr Met Thr Cys Ser Ser 210 215 220 Glu Gly Leu Pro Ala Pro Glu He Phe Trp Ser Lys Lys Leu Asp Asn 225 230 235 240 Gly Asn Leu Gin His Leu Ser Gly Asn Ala Thr Leu Thr Leu He Ala 245 250 255 Met Arg Met Glu Asp Ser Gly He Tyr Val Cys Glu Gly Val Asn Leu 260 265 270 He Gly Lys Asn Arg Lys Glu Val Glu Leu He Val Gin Glu Lys Pro 275 280 285 Phe Thr Val Glu He Ser Pro Gly Pro Arg He Ala Ala Gin He Gly 290 295 300 Asp Ser Val Met Leu Thr Cys Ser Val Met Gly Cys Glu Ser Pro Ser 305 310 315 320 Phe Ser Trp Arg Thr Gin He Asp Ser Pro Leu Ser Gly Lys Val Arg 325 330 335 Ser Glu Gly Thr Asn Ser Thr Leu Thr Leu Ser Pro Val Ser Phe Glu 340 345 350 Asn Glu His Ser Tyr Leu Cys Thr Val Thr Cys Gly His Lys Lys Leu 355 360 365 Glu Lys Gly He Gin Val Glu Leu Tyr Thr Phe Pro Arg Asp Pro Glu 370 375 380 He Glu Met Ser Gly Gly Leu Val Asn Gly Ser Ser Val Thr Val Ser 385 390 395 400 Cys Lys Val Pro Ser Val Tyr Pro Leu Asp Arg Leu Glu He Glu Leu 405 410 415 Leu Lys Gly Glu Thr He Leu Glu Asn He Glu Phe Leu Glu Asp Thr 420 425 430 Asp Met Lys Ser Leu Glu Asn Lys Ser Leu Glu Met Thr Phe He Pro 435 440 445 Thr He Glu Asp Thr Gly Lys Ala Leu Val Cys Gin Ala Lys Leu His 450 455 460 He Asp Asp Met Glu Phe Glu Pro Lys Gin Arg Gin Ser Thr Gin Thr 465 470 475 480 Leu Tyr Val Asn Val Ala Pro Arg Asp Thr Thr Val Leu Val Ser Pro 485 490 495 Ser Ser He Leu Glu Glu Gly Ser Ser Val Asn Met Thr Cys Leu Ser 500 505 510 Gin Gly Phe Pro Ala Pro Lys He Leu Trp Ser Arg Gin Leu Pro Asn 515 520 525 Gly Glu Leu Gin Pro Leu Ser Glu Asn Ala Thr Leu Thr Leu He Ser 530 535 540 Thr Lys Met Glu Asp Ser Gly Val Tyr Leu Cys Glu Gly He Asn Gin 545 550 555 560 Ala Gly Arg Ser Arg Lys Glu Val Glu Leu He He Gin Val Thr Pro 565 570 575 Lys Asp He Lys Leu Thr Ala Phe Pro Ser Glu Ser Val Lys Glu Gly 580 585 590 Asp Thr Val He He Ser Cys Thr Cys Gly Asn Val Pro Glu Thr Trp 595 600 605 He He Leu Lys Lys Lys Ala Glu Thr Gly Asp Thr Val Leu Lys Ser 610 615 620 He Asp Gly Ala Tyr Thr He Arg Lys Ala Gin Leu Lys Asp Ala Gly 625 630 635 640 Val Tyr Glu Cys Glu Ser Lys Asn Lys Val Gly Ser Gin Leu Arg Ser 645 .650 655 Leu Thr Leu Asp Val Gin 660 (2) INFORMATION FOR SEQ ID NO:8: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 20 bases (B) TYPE: nucleic acid (D) TOPOLOGY: linear (ii) MOLECULAR TYPE: nucleic acid (Xi) SEQUENCE DESCRIPTION: SEQ ID NO:8: AATTTATGTG TGTGAAGGAG 20 _ (2) INFORMATION FOR SEQ ID NO:9: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 17 bases (B) TYPE: nucleic acid (D) TOPOLOGY: linear (ii) MOLECULAR TYPE: nucleic acid (Xi) SEQUENCE DESCRIPTION: SEQ ID NO:9: TTCTGTGAAT ATGACAT 17 (2) INFORMATION FOR SEQ ID NO:10: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 32 bases (B) TYPE: nucleic acid (D) TOPOLOGY: linear (ii) MOLECULAR TYPE: nucleic acid (Xi) SEQUENCE DESCRIPTION: SEQ ID NO:10: GGGTCATATA GTCTTGTAGA AGCACAGAAA TC 32 (2) INFORMATION FOR SEQ ID NO:11: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 32 bases (B) TYPE: nucleic acid (D) TOPOLOGY: linear (ii) MOLECULAR TYPE: nucleic acid (xi) SEQUENCE DESCRIPTION: SEQ ID NO:11: GAGCTGAATA CCCTCCCAGG CACACACAGG TG 32 (2) INFORMATION FOR SEQ ID NO:12: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 27 bases (B) TYPE: nucleic acid (D) TOPOLOGY: linear (ii) MOLECUI^R TYPE: nucleic acid (xi) SEQUENCE DESCRIPTION: SEQ ID NO:12: GGGTTTTGGA ACCACTATTT TGTCATC 27 (2) INFORMATION FOR SEQ ID NO:13: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 32 bases (B) TYPE: nucleic acid (D) TOPOLOGY: linear (ii) MOLECULAR TYPE: nucleic acid (xi) SEQUENCE DESCRIPTION: SEQ ID NO:13: GTTTAACACT TGATGTTCAA GGAAGAGAAA ACTAA 35

Claims: We claim: 1. A substantially purified protein comprising a mononuclear leukocyte-selective endothelial-leukocyte adhesion molecule expressed in atherosclerotic lesions (ATHERO-ELAM). 2. The protein of claim 1 wherein said ATHERO-ELAM has a molecular weight of approximately 118 kD. 3. The protein of claim 1 wherein said ATHERO-ELAM has a molecular weight of approximately 98 kD. 4. The protein of claim 1 having the amino acid sequence as shown in Sequence ID 2. 5. The protein of claim 1 wherein said protein is encoded by the nucleotide sequence as shown in Sequence ID 1. 6. A monoclonal antibody capable of binding to ATHERO- ELAM. 7. A monoclonal antibody having the binding charac¬ teristics of monoclonal antibody Rbl/9. 8. A monoclonal antibody having the binding charac¬ teristics of monoclonal antibody Rb2/4. 9. A method of diagnosing atherosclerosis in a mammal comprising detecting ATHERO-ELAM expression by arterial endothelial cells in said mammal. 10. The method of claim 9 comprising exposing said arterial endothelial cells to an antibody capable of binding to ATHERO-ELAM, and detecting said bound antibody. 11. The method of claim 10 wherein said antibody is detectably labeled. 12. The method of claim 11 wherein said antibody is radiolabeled. 13. The method of claim 10 wherein said antibody has the binding characteristics of monoclonal antibody Rbl/9. 14. A method of preventing monocyte binding to endo¬ thelial cells comprising exposing said endothelial cells to an antibody capable of binding to a mononuclear leukocyte- selective adhesion . molecule expressed on said endothelial cells. 15. The method of claim 14 wherein said adhesion molecule is ATHERO-ELAM. 16. The method of claim 15 wherein said adhesion molecule comprises a protein having the amino acid sequence as shown in Sequence ID 2. 17. The method of claim 15 wherein said adhesion molecule comprises a protein encoded by the nucleotide sequence as shown in Sequence ID 1. 18. The method of claim 14 wherein said antibody is a monoclonal antibody. 19. The method of claim 18 wherein said monoclonal antibody has the binding characteristics of monoclonal antibody Rbl/9. 20. A method of treating a mammal suspected of having an atherosclerotic lesion, said method comprising administering to said mammal a composition comprising a pharmaceutically effective amount of a monoclonal antibody, wherein said monoclonal antibody is capable of binding to a mononuclear leukocyte-selective adhesion molecule expressed in said lesion. 21. The method of claim 20 wherein said adhesion molecule is ATHERO-ELAM. 22. The method of claim 20 wherein said adhesion molecule comprises a protein having the amino acid sequence as shown in Sequence ID 2, or a monocyte-binding equivalent of said protein. 23. The method of claim 20 wherein said adhesion molecule comprises a protein encoded by the nucleotide sequence as shown in Sequence ID 1, or a monocyte-binding equivalent of said protein. 24. The method of claim 20 wherein said monoclonal antibody has the binding characteristics of monoclonal Rbl/9. 25. The method of claim 20 wherein said mammal is a human. 26. The method of claim 20 wherein said composition further comprises a pharmaceutically acceptable carrier. 27. A method of treating a mammal having an atheroscler¬ otic lesion, said method comprising administering to said mammal a composition comprising a pharmaceutically effective amount of ATHERO-ELAM or a monocyte-binding fraction thereof. 28. The method of claim 27 wherein said ATHERO-ELAM comprises a protein having the amino acid sequence as shown in Sequence ID 2, or a monocyte-binding equivalent of said protein. 29. The method of claim 27 wherein said ATHERO-ELAM comprises a protein encoded by the nucleotide sequence as shown in Sequence ID 1, or a monocyte-binding equivalent of said protein. 30. The method of claim 27 wherein said mammal is a human. 31. The method of claim 27 wherein said composition further comprises a pharmaceutically acceptable carrier. 32. A composition for preventing adhesion of monocytes to an atherosclerotic lesion, comprising a therapeutically effective amount of an ATHERO-ELAM specific antibody, or antibody fragment capable of binding to ATHERO-ELAM, together with a pharmaceutically effective carrier. 33. A composition for detecting an atherosclerotic lesion, comprising an antibody or a fragment thereof, capable of binding to ATHERO-ELAM, wherein said antibody is detectably labeled. 34. The composition of claim 33., wherein said antibody has the binding characteristics of an antibody chosen from the group consisting of monoclonal antibodies Rbl/9 and Rb2/4. 35. A method for detecting an atherosclerotic lesion in an individual, said method comprising: (a) administering to said individual a composition comprising an immunoglobulin molecule or fragment thereof diagnostically conjugated to a detectable label, capable of binding to ATHERO-ELAM, wherein said labeled immunoglobulin substantially accumulates at said atherosclerotic lesion, and (b) detecting the presence of said labeled immuno- globulin. 36. The method of claim 35 wherein said immunoglobulin is selected from the group consisting of a monoclonal antibody and a polyclonal antibody. 37. The method of claim 36 wherein said monoclonal antibody has the binding characteristics of a monoclonal antibody chosen from the group consisting of Rbl/9 and Rb2/4. 38. The method of claim 35 wherein said detectable label is a radioactive isotope. 39. The method of claim 38 wherein said radioactive isotope is chosen from the group consisting of l^In, 99mj C) 123 I, 9 Rv, 67 CU) 67 Ga , 68 Ga> 72 As> 89 Zr and 201 π . 40. A method of treating atherosclerosis in an indivi- dual, said method comprising administering to said individual a pharmaceutically effective amount of an anti-atherosclerotic drug conjugated to an immunoglobulin molecule or fragment thereof wherein said immunoglobulin is capable of binding to ATHERO-ELAM. 41. The method of claim 40, wherein said immunoglobulin is selected from the group consisting of a monoclonal antibody and a polyclonal antibody. 42. The method of claim 41, wherein said monoclonal antibody has the binding characteristics of a monoclonal antibody chosen from the group consisting of Rbl/9 and Rb2/4. 43. The method of claim 40, wherein said anti-athero¬ sclerotic drug is chosen from the group containing anti- proliferative, anti-inflammatory, anti-oxidant and anti¬ coagulant drugs. 44. A substantially purified protein comprising the water-soluble part of ATHERO-ELAM. 45. The protein of claim 44 comprising the sequence between amino acids 1 and 774 in Sequence ID 2. 46. A composition useful for preventing adhesion of mononuclear leukocytes to endothelium in vivo, said composition comprising the protein of claim 44 or 45 or a mononuclear leukocyte binding equivalent thereof, and a pharmaceutically acceptable carrier. 47. A method of preventing atherosclerosis in an individual, wherein said method comprises administration to said individual of an amount of the composition of claim 46 effective to prevent the adhesion of mononuclear leukocytes to endothelium. 48. The method of claim 47 wherein said individual is a human.

Inventors: COLLINS TUCKER, CYBULSKY MYRON I, GIMBRONE MICHAEL A JR, COLLINS, TUCKER, CYBULSKY, MYRON, I., GIMBRONE, MICHAEL, A., JR.
Applicants: BRIGHAM & WOMENS HOSPITAL, BRIGHAM AND WOMEN'S HOSPITAL
Application year: 1991
Main classification: G01N33
IPC codes: A61K38, A61K39, A61K45, A61K49, A61P9, C07K14, C07K16, C12N15, C12P21, C12R1, G01N33