bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic markers of the antigen-specific T cell receptor locus.
Authors: Epstein R , Roehm N , Marrack P , Kappler J , Davis M , Hedrick S , Cohn M
Published: June 2004

The restriction enzyme Eco RI reveals DNA cleavage sites that serve to distinguish the gene locus believed to encode the beta subunit of the major histocompatibility complex (MHC)-restricted, antigen-specific receptor of the T cell in BALB/c mice from that of SJL/J mice. A monoclonal antibody, KJ16-133, also distinguishes BALB/c and SJL/J, because it recognizes an allotypic marker present on a cell-surface heterodimer believed to function as the MHC-restricted, antigen-specific T cell receptor. This study has shown that these two markers cosegregate in a set of BALB/c X SJL/J recombinant inbred (RI) mouse strains, permitting the conclusion that they are linked to within 3 centimorgans of each other, and to the kappa locus on chromosome 6. The tight linkage between these independently derived, totally different T cell markers substantially strengthens the argument that they characterize the MHC-restricted antigen-specific receptor of the effector T cell.
Interleukin 2-induced proliferation of leukemic human B cells.
Authors: Lantz O , Grillot-Courvalin C , Schmitt C , Fermand J P , Brouet J C
Published: June 2004

The proliferative responses of purified leukemic human B cells from nine B cell chronic lymphocytic leukemias to recombinant interleukin 2 (IL-2), spontaneously, and after preactivation by Staphylococcus aureus Cowan I (SAC) or anti-mu antibodies were studied. Three patterns of response were observed: (a) no response (three cases); (b) a moderate spontaneous response enhanced by anti-mu (one case); (c) a high proliferative response after preactivation by anti-mu and/or SAC (five cases). IL-2 could also trigger normal B cells, purified from spleen, to proliferative after preactivation by anti-mu or SAC. These results provide evidence that IL-2 is a lymphokine that acts physiologically on both B and T cells.
T cell tolerance studied at the level of antigenic determinants. I. Latent reactivity to lysozyme peptides that lack suppressogenic epitopes can be revealed in lysozyme-tolerant mice.
Authors: Oki A , Sercarz E
Published: June 2004

Whether T cell tolerance represents direct inactivation of antigen-specific T cells via recognition of antigen plus major histocompatibility complex, or via T suppressor (Ts) cells, or a combination of these mechanisms, remains to be clarified. This problem was investigated using a novel approach based on the finding in several systems that T helper/proliferative (Th/Tp) cell-inducing antigenic determinants are dissociable from Ts cell-inducing determinants. Thus, peptide probes containing known sites that stimulate T proliferative activity, as well as peptides from distinct sites assumed to bear Ts-inducing determinants, were used in studying hen (chicken) eggwhite lysozyme (HEL)-tolerant mice. The clear prediction from clonal deletion model is that Th/Tp response potential to short peptides in the tolerant mouse would not exist, while regulatory suppression models predict the coexistence of antigen-reactive cells and antigen-specific regulatory cells that prevent their expression. Adult mice, treated with 2 mg HEL in saline, were tolerant to HEL in complete Freund's adjuvant (CFA). Latent T cell proliferative responses could be revealed to determinants within two HEL peptide probes, which lacked the amino-terminal region of the molecule. This responsiveness suggested two conclusions: first, Ts cells directed against the amino terminus of lysozyme exist in the tolerant genetic responder B10.A; second, these Ts regulate the activity of functional antigen-reactive T cells directed against epitopes elsewhere on the molecule, but only in the presence of the complete molecule, HEL. Examination of neonatally induced tolerance did not reveal any latent responsiveness, supporting the hypothesis that clonal deletion or anergy is the relevant mechanism in this situation. Possible reservations in these explanations of the two tolerant states, plus analysis of the more complex "split tolerance" resulting from 20 mg HEL in saline treatment in adults, are discussed. The approach of dissociation of proliferation-inducing determinants from suppression-inducing determinants clarifies our understanding of the tolerant state and holds promise for more definitive exploration of mechanisms of T cell tolerance.
Expression and T cell recognition of hybrid antigens with amino-terminal domains encoded by Qa-2 region of major histocompatibility complex and carboxyl termini of transplantation antigens.
Authors: Stroynowski I , Forman J , Goodenow R S , Schiffer S G , McMillan M , Sharrow S O , Sachs D H , Hood L
Published: June 2004

Coding potential of the Q6 gene from the Qa-2a region of BALB/c Crgl mice was analyzed by a combination of hybrid class I gene construction and DNA-mediated gene transfer. Recombinant genes were created by exon shuffling of the 5' coding region of the Q6 gene and the 3' coding region of a gene encoding a transplantation antigen (Kd, Dd, or Ld), or the inverse. Some of these hybrid class I genes were expressed in the transfected mouse fibroblasts (L cells). The hybrid class I molecules encoded by the 5' end of the Q6 gene and the 3' end of the Ld gene precipitated as 45,000 mol wt molecules associated with beta 2-microglobulin. The expression of the hybrid proteins indicates that 926 basepairs of the 5' flanking region upstream of the structural Q6 gene contain a promoter that functions as a transcription initiation site in L cells. The 3' portion of the Q6 gene appears to be responsible for the lack of cell surface expression of the intact Q6 and the hybrid Ld/Q6 genes in mouse fibroblasts. Accordingly, this portion of the Q6 class I gene may play a regulatory role in tissue-specific expression. Serological analyses of hybrid Q6 proteins suggested that Q6 may be a structural gene for CR (H-2 crossreactive) antigen found normally on subpopulations of lymphocytes. If this identification is correct, Q6 gene will define a new category of class I genes encoding approximately 40,000 mol wt molecules and carrying a characteristic truncated cytoplasmic tail. Analysis of L cells transfected with Q6 hybrid genes demonstrated also that the cytotoxic T cells specific for Qa-2a region-coded antigens recognize the amino-terminal alpha 1-alpha 2 domain of Q6 fusion products. This recognition can be blocked by anti-Qa-2a alloantiserum and monoclonal antibodies reactive with the alpha 3-beta 2-microglobulin portion of the Q6 hybrids. We propose that the structural requirements for the anti-Qa-2a cytotoxic T lymphocyte-specific epitopes on target molecules are the same as for anti-H-2-alloreactive cytotoxic T lymphocyte determinants on transplantation antigens and that the mechanism of target recognition is similar in both cases. This interpretation is consistent with the following structural similarities found in both categories of class I molecules: (a) Kd and Q6 alpha 1-alpha 2 domains share serologically defined epitopes.(ABSTRACT TRUNCATED AT 400 WORDS)
Absence of platelet membrane glycoproteins IIb/IIIa from monocytes.
Authors: Clemetson K J , McGregor J L , McEver R P , Jacques Y V , Bainton D F , Domzig W , Baggiolini M
Published: June 2004

Two-dimensional gel electrophoresis, immunoprecipitation, and crossed immunoelectrophoresis were used in the investigation of glycoproteins IIb/IIIa in platelets, monocytes, and monocyte-derived macrophages from human blood. All techniques detected the glycoproteins in platelets but not in the mononuclear phagocytes. Similar results were obtained by immunochemistry using a monoclonal antibody against the platelet glycoproteins IIb/IIIa (revealed by a gold-labeled second antibody) which bound heavily to the platelet but not to the monocyte surface. The biochemical techniques used for the analysis of mononuclear phagocytes would have reliably detected the level of glycoproteins IIb/IIIa contributed by a 5% contamination with platelets, calculated on a per cell basis. We conclude that human monocytes and monocyte-derived macrophages lack glycoproteins IIb/IIIa. Our results further indicate that centrifugal elutriation yields monocyte preparations with minimal contamination by platelets. It seems likely that the positive results obtained by other authors were due to the presence of platelets or fragments on the monocytes.
Heavy chain variable region. Multiple gene segments encode anti-4-(hydroxy-3-nitro-phenyl)acetyl idiotypic antibodies.
Authors: Boersch-Supan M E , Agarwal S , White-Scharf M E , Imanishi-Kari T
Published: June 2004

The hapten (4-hydroxy-3-nitrophenyl)acetyl (NP), when conjugated to carrier proteins, elicits a characteristic idiotypic response (NPb) in C57BL/6 mice. The response can be divided serologically into two distinct NPb-positive groups of antibodies. The first group consists of four crossreacting subgroups (I-IV), the second of two subgroups (V, VI). Some antibodies of subgroups I and II have been shown to express the unmutated heavy chain variable region (VH) germline gene 186.2. Antibodies of subgroups V and VI crossreact extensively with the NPa-positive antibodies of BALB/c mice. We sequenced heavy chain complementary DNA from eight hybridomas producing anti-NP antibodies. Six of these belong to subgroups V and VI, and two were NPa-positive hybridomas of BALB/c origin. All sequences were homologous to each other, and differed by approximately 80 basepairs from the 186.2 C57BL/6 germline VH gene. From our sequence and Southern blot analyses we suggest: (a) the NPb idiotypic response is the product of several VH germline genes, (b) some of these genes are very homologous to the gene coding for the BALB/c NPa idiotype, and might represent the C57BL/6 allelic forms of this gene, (c) the diversity regions of NPb and NPa-positive antibodies are diverse in length and amino acid composition, except for the first residue, which is always tyrosine, (d) all four heavy chain joining region gene segments are expressed without mutation. We discuss our data in terms of diversity in the germline VH gene repertoire, as well as diversity created by gene segment-joining events and somatic mutation.
Variable major proteins of Borrelia hermsii. Epitope mapping and partial sequence analysis of CNBr peptides.
Authors: Barstad P A , Coligan J E , Raum M G , Barbour A G
Published: June 2004

The variable major proteins (VMP) of serotypes 7 and 21 of the relapsing fever agent Borrelia hermsii were isolated by detergent extraction and high performance liquid chromatography. Cyanogen bromide (CNBr) digestion of the isolated VMP yielded two peptides of apparent molecular weights 20,000 (20 K) and 16 K from VMP7, and three peptides of 14.5, 14, and 7 K mol wt from VMP21. Serotype-specific monoclonal antibodies bound in Western blots to one of each of the two or three CNBr fragments from the homologous VMP. A single monoclonal antibody bound to the whole cells, the isolated VMP, and a CNBr fragment of both serotype 7 and serotype 21. (This crossreactive antibody did not, however, bind to any of four other serotypes examined.) Regional conservation of structure between VMP7 and VMP21 was also shown by amino acid sequence analysis of the N-termini of the five CNBr fragments. One pair of aligned fragments from VMP7 and VMP21 had 80% amino acid homology in sequence; a second pair had 40% homology. The partial amino acid homologies between two VMP suggest that these proteins are products of members of a polygene family.
The Thy-1-bearing cell of murine epidermis. A distinctive leukocyte perhaps related to natural killer cells.
Authors: Romani N , Stingl G , Tschachler E , Witmer M D , Steinman R M , Shevach E M , Schuler G
Published: June 2004

Bone marrow-derived leukocytes of murine epidermis can express two phenotypes: typical Langerhans cells, which are Ia+ and Thy-1-, and a recently discovered second population that is Thy-1+ and Ia-. To verify that these phenotypes are expressed by two different cell types, and to help understand their lineage and function, we have studied morphology and reactivity with a large panel of antibodies. Dual antibody immunofluorescence combined with electron microscopy showed that Thy-1+ and Ia+ cells were each distributed in a regular fashion and formed adjacent dendritic systems in or close to the basal layer. Double-labeling studies with anti-Ia and a second monoclonal antibody revealed that all Langerhans cells expressed F4/80 (macrophage), Mac-1 (C3bi receptor), and 2.4G2 (Fc receptor), as well as the thymus leukemia (TL) and heat-stable (M1.69/16) antigens. A large fraction expressed S100 and all exhibited membrane ATPase and nonspecific esterase. In contrast, Thy-1+ cells lacked all these features of Langerhans cells, except that a minority were strongly reactive with 2.4G2. Thy-1+ cells also lacked differentiation antigens of most other types of leukocytes, except they were rich in asialo GM1. By electron microscopy, Thy-1+ cells had cytoplasmic granules that were similar in structure and in their aryl sulfatase content to those previously described in natural killer cells. The granules were enlarged in beige mice, suggesting a lysosomal origin, and were present in mast cell-deficient W/Wv mice, indicating no relation to mast cells. We conclude that Thy-1+ epidermal cells are thoroughly distinct from Langerhans cells. On the basis of morphology and phenotype, they may represent a type of tissue natural killer cell. Thy-1+ natural killer cells are now being identified in several nonlymphoid sites, such as gut epithelium and the livers of mice given adjuvants. If Thy-1+ epidermal cells prove to be natural killer cells, it is noteworthy that they represent a resident population regularly distributed in the basal layer of all mouse strains. The notion that Thy-1+ epidermal cells are immature natural killer cells is intriguing in light of recent evidence that Ia+ Langerhans cells are also immature with respect to accessory cell function. The epidermis may not have the functional capacities of a lymphoid organ, but it could contribute immature cells important for both natural and acquired resistance.
Size variation of the M protein in group A streptococci.
Authors: Fischetti V A , Jones K F , Scott J R
Published: June 2004

In addition to the type-specific antigenic variation that is a well-known characteristic for the group A streptococcal M protein, we have now found that the M molecules vary with respect to their molecular size, both between M types and within an M type. By the use of an M6 monoclonal antibody, which crossreacts with 20 different M protein types, and antibodies to the N-acetyl glucosamine determinant of the cell wall, we have been able to identify the M protein molecules released from the streptococcal cell wall with muralytic enzymes, particularly group C phage-associated lysin. Immunoblot analysis of the cell extract identified M protein molecules bound to various cell wall fragments, suggesting a peptidoglycan linkage for the M molecule. M protein extracted from 20 different streptococcal serotypes revealed size variations from 41,000 to 80,000 in molecular weight. This extreme variation is unusual for related proteins. Similar size variations in the M molecule were also found in random clinical isolates of type 6 streptococci. No size change was seen in M6 protein isolated from: (a) strains within a limited epidemic, (b) a strain passaged in mice 192 times, and (c) a strain passaged in the laboratory for 156 generations, suggesting that the observed variation is not a rapid process. The results indicate that, within the broad limits observed in this study, the size of the M protein may not be critical to the antiphagocytic activity of the molecule.
Immunochemical similarities between monoclonal antibacterial Waldenstrom's macroglobulins and monoclonal anti-DNA lupus autoantibodies.
Authors: Naparstek Y , Duggan D , Schattner A , Madaio M P , Goni F , Frangione B , Stollar B D , Kabat E A , Schwartz R S
Published: June 2004

Six monoclonal IgM from patients with Waldenstrom's macroglobulinemia that react with Klebsiella polysaccharides were tested for their ability to bind to nucleic acid antigens. One of the macroglobulins bound to the polynucleotide poly(G), and one bound to poly(G), poly(I), and single-stranded DNA. The reaction with the polynucleotides was specifically inhibited by the Klebsiella polysaccharide K30. A monoclonal lupus anti-DNA antibody (16/6) was found to react weakly with the Klebsiella polysaccharides K30 and K21. Five of the Waldenstrom macroglobulins shared an idiotypic determinant with the 16/6 anti-DNA antibody. The reaction between the macroglobulins and the antiidiotype serum was specifically inhibited by Klebsiella polysaccharides, an indication that the idiotypic marker was in the antigen-binding site of the macroglobulins. These results indicate the existence of widely dispersed conserved variable region genes that encode idiotypically related immunoglobulins with the capacity to bind to both bacterial polysaccharides and nucleic acids. Such genes can be expressed by patients with either Waldenstrom's macroglobulinemia or systemic lupus erythematosus.
Hidden autoantibodies against common serum proteins in murine systemic lupus erythematosus. Detection by in vitro plaque-forming cell assay.
Authors: Cohen P L , Rapoport R G , Eisenberg R A
Published: June 2004

The autoantibodies found in human and murine systemic lupus erythematosus (SLE) are generally directed against cells or components of cells such as nuclear antigens. This predilection may be due to the unusual immunogenicity of certain autoantigens, or to unusual patterns of antibody crossreactivity. Alternatively, the observed spectrum of reactivities may reflect the in vivo absorption of those autoantibodies directed against soluble antigens. To test whether hitherto undetected autoantibodies against serum proteins might exist in murine SLE, we developed assays that were independent of the possibility of absorption of autoantibodies by serum autoantigens; large numbers of plaque-forming cells (PFC) directed against mouse albumin and mouse transferrin were easily detected in the spleens of MRL/Mp-lpr/lpr, BXSB, and NZB mice. The secreted antibodies were relatively specific for the mouse proteins, since only limited cross-reactivity was seen with albumin and transferrins of other species in inhibition experiments. The production of these hidden antibodies could not be the result of diffuse polyclonal B cell activation, since the PFC to mouse transferrins and albumin were not always accompanied by comparable numbers of PFC against related albumins and transferrins. The results indicate that autoantibody production in murine lupus is a generalized phenomenon, not limited to the production of autoantibodies to nuclear or other cell-bound antibodies. However, the relative specificity of the autoantibodies for self-antigens indicates that diffuse polyclonal B cell activation cannot be the mechanism responsible, and argues that a selective mechanism, probably driven by antigen, accounts for production of autoantibodies in SLE.
Serological and immunochemical analysis of the products of a single HLA DR-alpha and DR-beta chain gene expressed in a mouse cell line after DNA-mediated cotransformation reveals that the beta chain carries a known supertypic specificity.
Authors: Gorski J , Tosi R , Strubin M , Rabourdin-Combe C , Mach B
Published: June 2004

Using a mouse cell line transformed with and expressing a single HLA DR-alpha and DR-beta chain gene, we present evidence that the product of the DR-beta chain gene carries a supertypic determinant, BR3, previously defined by serology. The amino acid sequence of this beta chain gene is determined from the DNA sequence. Another DR-associated supertypic specificity defined by monoclonal antibody MCS7 was not encoded by this DR-beta chain gene. This provides formal proof that a supertypic specificity can be associated with a product of a distinct DR-beta locus. We propose that haplotypes sharing such specificities are evolutionarily related.
Distinct functional phenotypes of cloned Ia-restricted helper T cells.
Authors: Kim J , Woods A , Becker-Dunn E , Bottomly K
Published: June 2004

Analysis of activation of phosphorylcholine (PC)-specific B cells by a large number of different cloned, self Ia-specific helper T cell (Th) clones has permitted the classification of such T cells into four distinct functional types. Types 1 and 2 induce B cells to secrete anti-PC antibody in an antigen-specific, Ia-restricted fashion. Type 3 cells induce antigen-specific, Ia-restricted B cell proliferation, but do not lead to specific antibody formation, and have been shown previously to have suppressor functions. Type 4 cells are autoreactive, and induce antigen-independent B cell activation and antibody secretion. The distinction between type 1 and type 2 Th clones was analyzed in detail. In bulk cultures, type 1 cloned lines generate an idiotypically heterogeneous anti-PC antibody response, whereas type 2 cloned lines induce a larger response that is dominated by the T15 idiotype. In limiting-dilution analyses, type 2 cells induce fourfold more T15+, PC-specific precursor B cells than do type 1 cells, and in addition, induce larger burst sizes for T15+, PC-specific B cells. Type 4 clones can also be subdivided into cells that are type 1-like, and cells that are type 2-like. These differences in functional phenotype are seen over a broad range of antigen and cell doses. Detailed analysis of the behavior of these distinct functional types of Th should allow a better understanding of the functional properties of mixed populations of antigen-primed, Ia-restricted Th cells.
Podoendin. A new cell surface protein of the podocyte and endothelium.
Authors: Huang T W , Langlois J C
Published: June 2004

A new cell surface protein, podoendin, has been identified in Sprague-Dawley rats, and isolated using monoclonal antibody (mAb) G4. The distribution of podoendin is restricted to the surface of glomerular podocytes, urinary surface of the parietal epithelium of Bowman's capsule, and the luminal surface of endothelial cells. The antibody does not crossreact with podocytes or endothelia of human or mice. In newborn rats, the appearance of podoendin on glomerular epithelium is attendant on podocyte differentiation during glomerulogenesis of metanephrogenic vesicles. It disappears when podocytes retract and efface foot processes in tissue culture. Thus, podoendin appears to be a cell differentiation-dependent surface protein of podocytes. Podoendin is a protein of 62 kD mobility on 5% polyacrylamide gel electrophoresis. It stains intensely with Coomassie blue, but gives negative reactions to carbohydrate (periodic acid/Schiff reaction) and polyanions (alcian blue, colloidal iron, and carbocyanine). It is distinct from the major sialoglycoprotein of podocyte fuzzy coat, podocalyxin (11). Podoendin isolated and purified from endothelium of lungs appears to be identical with that from podocytes and endothelium of kidneys. Injection of mAb G4 into left ventricle of rats resulted in intense decoration of the endothelium and podocyte surface within 30 min. The decoration persisted throughout the 3-d period of observation. This was not accompanied by complement (C3) fixation. Preliminary results showed that the rats developed moderate proteinuria (100 mg/ml protein in urine), which was associated with the presence of hyaline droplets in renal tubules, on the third day. The proteinuria was not accompanied by effacement of podocyte pedicels. There were no morphologic alterations indicating glomerular or vascular injury in the kidneys.
Polymorphism of Fc receptor on murine B cells is Igh-linked.
Authors: Baum C M , McKearn J P , Riblet R , Davie J M
Published: June 2004

Analysis of mouse IgG binding to Fc receptors on mouse B cells indicates that the IgG1, IgG2a, and IgGb subclasses bind to the same receptor. No differences in affinity were detected among subclass or between mouse strains. This same receptor bound rat IgG with an affinity that differed between mouse strains. This polymorphism in affinity for rat IgG maps to chromosome 12 distal to the Igh locus.
Repertoires of T cells directed against a large protein antigen, beta-galactosidase. II. Only certain T helper or T suppressor cells are relevant in particular regulatory interactions.
Authors: Krzych U , Fowler A V , Sercarz E E
Published: June 2004

11 cyanogen bromide (CB) peptides, comprising 70% of the large protein, Escherichia coli beta-galactosidase (GZ), were studied for their ability to induce T suppressor (Ts) cells capable of strongly suppressing the in vitro anti-fluorescein (FITC) response to GZ-FITC. Only CB-2 (amino acid residues 3-92) and CB-3 (residues 93-187) were found to bear such Ts-inducing epitopes. In examining the specificity of T helper cell (Th) targets susceptible to CB-2 and CB-3-specific Ts, it appeared that only nearly Th targets could be suppressed. Thus, CB-10-primed Th were not suppressed by either Ts; even CB-3-primed Ts did not suppress CB-2-specific Th, although CB-2-specific Ts were effective. Furthermore, analysis of the suppression pattern revealed a hierarchical use of potential epitopes on native GZ in triggering functional regulatory T cells. A dominant Th epitope near the amino terminus of GZ tops a hierarchy of potential Th, most of which are never engaged. The dominant determinant seems to exist on the peptide CB-2-3 (residues 3-187), and presumably is destroyed by its cleavage at Met 92; the Th cells that it induces are suppressible by each of the Ts-inducing peptides. In the GZ system, where the native antigen is quite large, the interactions between Th and Ts are highly circumscribed. This may be attributable to the topology of antigen fragments produced during processing; any relevant fragment must bear at least a Ts- and Th-reactive determinant to permit intercellular regulation. A final implication of these results is that, not only does the existence of a Th-inducing determinant depend on its being an appropriate distance from a B cell epitope, but the existence of Ts-inducing determinants likewise depends on the existence of a neighboring Th-B cell association.
Administration of an anti-interleukin 2 receptor monoclonal antibody prolongs cardiac allograft survival in mice.
Authors: Kirkman R L , Barrett L V , Gaulton G N , Kelley V E , Ythier A , Strom T B
Published: June 2004

Administration of the monoclonal antibody M7/20, which binds to the murine interleukin-2 (IL) receptor, significantly prolongs cardiac allograft survival in two H-2-incompatible strain combinations of inbred mice. The results support the important role of the IL-2 receptor in the mechanism of graft rejection, and suggest its suitability as a target for immunosuppressive therapy.
Distribution of decay-accelerating factor in the peripheral blood of normal individuals and patients with paroxysmal nocturnal hemoglobinuria.
Authors: Kinoshita T , Medof M E , Silber R , Nussenzweig V
Published: June 2004

Decay-accelerating factor (DAF) is a 70,000 Mr protein that has been isolated from the membrane of red cells. The function of DAF is to inhibit the assembly of amplifying enzymes of the complement cascade on the cell surface, thereby protecting them from damage by autologous complement. We raised monoclonal antibodies to DAF and used them to study its distribution in cells from the peripheral blood of normal individuals and of patients with paroxysmal nocturnal hemoglobinuria (PNH), a disease characterized by the unusual susceptibility of red cells to the hemolytic activity of complement. The results of immunoradiometric assays and of fluorescence-activated cell sorter analysis showed that DAF was present not only on red cells but was widely distributed on the surface membrane of platelets, neutrophils, monocytes, and B and T lymphocytes. By Western blotting, we observed small but consistent differences in the Mr of DAF from the membranes of various cell types. Quantitative studies showed that phagocytes and B lymphocytes, which presumably enter more frequently in contact with immune complexes and other potential activators of complement, had the highest DAF levels. As previously reported by others, the red cells from PNH patients were DAF deficient. When the patients' red cells were incubated in acidified serum (Ham test), only the DAF-deficient cells were lysed. In addition, we detected defects in DAF expression on platelets and all types of leukocytes. The observed patterns of DAF deficiency in these patients were consistent with the concept that the PNH cells were of monoclonal origin. In one patient, abnormal and normal cells were found only in the erythroid, myeloid, and megakaryocytic lineages. In two other patients, the lymphocytes were also DAF deficient, suggesting that a mutation occurred in a totipotent stem cell. It appears, therefore, that the lesion leading to PNH can occur at various stages in the differentiation of hematopoietic cells.
Analysis of major histocompatibility complex haplotypes of t-chromosomes reveals that the majority of diversity is generated by recombination.
Authors: Artzt K , Shin H S , Bennett D , Dimeo-Talento A
Published: June 2004

t-chromosomes are natural polymorphisms in feral populations of mice that are thought to be descended from a single ancestral chromosome. They carry an inversion of at least 10 cM surrounding the major histocompatibility complex (MHC) that effectively prevents recombination between a t-bearing chromosome and wild type chromosomes. However, on the rare occasion when two different t-chromosomes meet in a wild female, recombination occurs at an apparently normal rate. Since they contain the highly polymorphic MHC, their limited origin and restricted chances for recombination make t-chromosomes a valuable tool for studying the relative contributions of mutation and recombination to the generation of diversity. Using 13 different serological reagents to class I antigens, and studying restriction enzyme polymorphisms detected with three molecular probes for class II genes examined with three endonucleases, we present data indicating that the major factor responsible for the diversity of class I antigens is recombination, but that for class II genes, mutation must play an important role in addition to recombination.
Necrotic inflammatory reaction induced by muramyl dipeptide in guinea pigs sensitized by tubercle bacilli.
Authors: Nagao S , Tanaka A
Published: June 2004

In the course of studies aimed at determining whether MDP was antigenic or not, a hitherto unreported phenomenon was noticed. Injection (a provocative injection) of muramyl dipeptide (MDP) caused severe inflammation, with hemorrhage and necrosis in the footpads of guinea pigs, where tubercle bacilli in water-oil emulsion (a preparatory injection) had been injected 3-8 wk earlier. Sometimes the reaction was accompanied by generalized and fatal shock. Several related substances were tested, and only a combination of tubercle bacilli, or MDP plus proteins as the preparatory injection, and MDP as the provocative injection was found to induce this inflammatory necrotic reaction. Development of delayed hypersensitivity to protein antigens may be important for priming, but MDP and not the protein antigens provoked the reaction. This reaction was, so far, only observed in guinea pigs. Although this reaction appears to be similar to the Shwartzman reaction, the two reactions were found to differ from each other in several important points.
Both L3T4+ and Lyt-2+ helper T cells initiate cytotoxic T lymphocyte responses against allogenic major histocompatibility antigens but not against trinitrophenyl-modified self.
Authors: Mizuochi T , Golding H , Rosenberg A S , Glimcher L H , Malek T R , Singer A
Published: June 2004

This study characterizes the T helper (Th) cells that initiate primary cytotoxic T lymphocyte (CTL) responses against allogeneic and trinitrophenyl (TNP)-modified self class I major histocompatibility (MHC) determinants. We show that two distinct Th cell subsets participate in allospecific CTL responses: (a) an L3T4+,Lyt-2- class II-restricted Th cell population, and (b) an L3T4-,Lyt-2+ class I-restricted Th cell population. Both of these T cell subpopulations were shown to function in allospecific CTL responses as helper cells by their ability to show synergy with allospecific CTL precursors. Thus, primary class I allospecific CTL responses represent an immune response involving not only L3T4+ Th cells, but Lyt-2+ Th cells as well. One of the necessary functions performed by both L3T4+ and Lyt-2+ Th cell populations in allospecific CTL responses was found to be the secretion of interleukin 2. Finally, despite the many similarities between anti-allo- and anti-TNP-CTL responses, anti-TNP-CTL responses were found to be mediated by only L3T4+ Th cells, not by Lyt-2+ Th cells. Consequently, Lyt-2+ Th cells appear to be a helper cell population that is primarily involved in MHC-specific immune responses.
Natural killer-mediated lysis of normal and malignant target cells, and its regulation by monocytes.
Authors: Oshimi K , Oshimi Y , Satake M , Mizoguchi H
Published: June 2004

After depletion of monocytes, natural killer (NK) cells were partially purified from peripheral blood by Percoll density gradient sedimentation. The NK cells were then cultured for 1 d and assayed for their cytotoxicity against various types of normal and malignant target cells. All types of target cells tested were found to be susceptible to NK cells. The susceptible targets were autologous T and B lymphocytes, mitogen-induced T and B blasts, monocytes, large granular lymphocytes, autologous or allogeneic lymphoma and leukemia cells isolated from patients, and cultured cell lines, including those resistant to interferon-activated lymphocytes. Such a broad spectrum of cytotoxicity was demonstrated in 1 d of culture, and freshly prepared NK cells were not cytotoxic, or, if anything, were less cytotoxic. Monocytes and their supernatants, added throughout the course of culture, markedly inhibited the development of their cytotoxicity. These results may suggest that, although NK cells having ability to lyse autologous normal and malignant target cells are present in vivo, their lytic activity is regulated by coexisting monocytes.
Detection and characterization of high affinity plasma membrane receptors for human interleukin 1.
Authors: Dower S K , Kronheim S R , March C J , Conlon P J , Hopp T P , Gillis S , Urdal D L
Published: June 2004

Interleukin 1 (IL-1) is a polypeptide hormone that acts as a central mediator of inflammation. Since IL-1 action is presumably mediated by specific cell surface receptor(s), we have characterized the binding of this hormone to cells. Purified human IL-1 was labeled to high specific activity with 125I, using Bolton-Hunter reagent. The labeled protein binds specifically to LBRM-33-1A5 (a murine T lymphoma line previously shown to produce IL-2 in response to phytohemagglutinin and IL-1) with an affinity of approximately 0.2-2 X 10(10)/M and, at saturation, to approximately 500 receptors per cell, on intact cells at 8 degrees C in the presence of sodium azide. The affinity of unmodified IL-1 for the murine plasma membrane receptor is 0.9-2 X 10(10)/M, as measured by the inhibition of 125I-IL-1 binding. The murine receptor specificity has been confirmed by demonstrating that, among a series of 12 polypeptide hormones, only IL-1 inhibits 125I-IL-1 binding to LBRM-33-1A5 cells. Treatment of surface-bound 125I-IL-1 with bivalent water-soluble crosslinkers identified a membrane polypeptide of Mr 79,500 to which IL-1 is crosslinked. A variety of cell types have been surveyed for the capacity to bind 125I-IL-1 specifically. The presence of specific binding correlates with the capacity of the cells tested to respond to IL-1. Our results indicate that the biological effects of the polypeptide hormone IL-1 are mediated by high affinity plasma membrane receptors. The identification of these receptors should provide valuable insight into the apparently diverse biological activities of IL-1.
Gamma interferon is the lymphokine and beta interferon the monokine responsible for inhibition of fibroblast collagen production and late but not early fibroblast proliferation.
Authors: Duncan M R , Berman B
Published: June 2004

Human peripheral blood mononuclear cells activated with concanavalin A (Con A) or lipopolysaccharide (LPS) produce, respectively, lymphokines (LK) of 50,000 Mr or monokines (MK) of 20,000 Mr that inhibit the growth and collagen production of cultured human dermal fibroblasts. Because antigenic typing of the antiviral activity of these LK and MK preparations revealed that LK contained mainly gamma interferon (IFN-gamma), and MK, primarily IFN-beta, we investigated if any of the fibroblast-inhibiting activities could be attributed to human IFN. Unlike LK and MK, which act within 24 h to inhibit the growth of subconfluent foreskin and adult dermal fibroblasts, samples of purified, natural derived IFN-alpha, -beta, and -gamma and recombinant DNA-derived IFN-alpha 2 and -gamma were ineffective inhibitors at 24 h and required 48-72 h to significantly inhibit growth. However, all IFN did mimic LK/MK action in causing concentration-dependent inhibition of collagen production by confluent fibroblast microcultures. Furthermore, the collagen production-inhibiting activity of Con A-induced LK supernatant and its 50,000 Mr fraction was completely suppressed by 10(3) neutralizing U/ml of either polyclonal or monoclonal antibody to IFN-gamma, while polyclonal antibodies to IFN-alpha and -beta had no effect. Similarly, the collagen production-inhibiting activity of LPS-induced MK supernatant and its 20,000 Mr fraction was suppressed by polyclonal anti-IFN-beta but not by anti-IFN-alpha or -gamma. Anti-IFN failed to reverse early-acting LK or MK growth-inhibiting activities. These data suggest collagen production-inhibiting LK and MK are IFN-gamma and IFN-beta, respectively, and that early acting, growth-inhibiting LK and MK are not IFN.
Expression of murine Lm-1 locus. Lm-1 determinants on lymphocytes and macrophages, and effects of Lm-1 incompatibility on bone marrow grafts.
Authors: O'Toole M M , Bosma G C , Bosma M J
Published: June 2004

Lm-1 is an Igh-linked locus that codes for cell surface alloantigens (Lm-1 determinants) recognized by T lymphocytes. Using Lm-1 congenic strains and cold-target inhibition of anti-Lm-1-specific lysis by cytotoxic T lymphocytes, we were able to demonstrate differential expression of two distinct Lm-1 antigenic determinants. One determinant is expressed on the surface of T cell blasts, the other on a number of pre-B cell lines. Both determinants are present on B cell blasts. Macrophages also bear Lm-1 determinants, and possibly express a determinant not found on lymphocytes. Fibroblasts, (unstimulated) thymocytes, and immature T cells lack detectable Lm-1 determinants. These data indicate that expression of the Lm-1 locus is dependent on cell lineage and the stage of cell differentiation or activation. We propose that Lm-1 is a lymphocyte-macrophage differentiation locus containing a number of structurally and functionally related genes. Evidence was presented that Lm-1 may also serve as a histocompatibility locus of major importance for bone marrow transplantation. Specifically, when Lm-1-incompatible bone marrow cells and spleen cells (from normal or anti-Lm-1 immune mice) were transplanted into X-irradiated recipients, the maturation and/or function of bone marrow-derived donor B cells was delayed or inhibited.
Influenza virus hemagglutinin-specific cytotoxic T cell response induced by polypeptide produced in Escherichia coli.
Authors: Yamada A , Ziese M R , Young J F , Yamada Y K , Ennis F A
Published: June 2004

We have tested the abilities of various polypeptides of A/PR/8/34 (H1N1) virus, constructed by recombinant DNA techniques, to induce influenza virus-specific secondary cytotoxic T lymphocyte (CTL) responses. A hybrid protein (c13 protein), consisting of the first 81 amino acids of viral nonstructural protein (NS1) and the HA2 subunit of viral hemagglutinin (HA), induced H-2-restricted, influenza virus subtype-specific secondary CTL in vitro, although other peptides did not. Using a recombinant virus, the viral determinant responsible for recognition was mapped to the HA2 portion of c13 protein. Immunization of mice with c13 protein induced the generation of memory CTL in vivo. The CTL precursor frequencies of A/PR/8/34 virus- and c13 protein-immune mice were estimated as one in 8,047 and 50,312, respectively. These results indicate that c13 protein primed recipient mice, even though the level of precursor frequency was below that observed in virus-immune mice.
Identification of Igh-C-linked determinants on suppressor T cell hybrids and factors specific for L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT).
Authors: Sorensen C M , Hayashi R J , Pierce C W
Published: June 2004

Hyperimmunization of BALB/c mice with concanavalin A-stimulated blasts from the Ig allotype-congenic strain, C.B20, results in the production of antibodies reactive with T cells in an allotype-restricted manner. Spleen cells from these hyperimmune BALB/c mice were used to generate a panel of hybridomas that secrete monoclonal antibodies, reactive, in an allotype-restricted manner, exclusively with T cells subpopulations, and in particular, reactive with suppressor T cell hybridomas and their secreted soluble factors. Two functional classes of antibodies were identified: those that react with single polypeptide-chain suppressor T cell factors (TsF1) and the suppressor T cell hybridomas that produce such factors, and those that react with two polypeptide-chain suppressor T cell factors (TsF2) and their corresponding suppressor T cell hybridomas. These two classes of antibody were used to isolate molecules from the membranes of the respective suppressor T cell hybrids that are functionally and structurally related to the secreted suppressor T cell factors, suggesting a receptor function for these molecules.
Structural characteristics of Tla products.
Authors: Chorney M J , Tung J S , Bushkin Y , Shen F W
Published: June 2004

Biochemical study of thymus leukemia antigen (TL) from thymocytes of various Tla genotypes and from leukemia cells revealed features that, given present evidence, are peculiar to TL among class I products of the H-2:Qa:Tla region of chromosome 17. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of TL from thymocytes of all TL+ mouse strains, precipitated by anti-TL antiserum or monoclonal antibodies, showed two closely migrating bands of equal intensity in the heavy (H) chain position (45-50,000 mol wt). Comparison of these two bands by two-dimensional isoelectric focusing (2D IEF)-SDS-PAGE and 2D chymotryptic peptide mapping showed no differences indicative of protein dissimilarity. Thus, the two components of the H chain doublet may differ only in a feature of glycosylation that does not affect charge. The two leukemias studied gave only a single band in the H chain position. On 2D peptide mapping and 2D IEF-SDS-PAGE, the patterns for TL of Tlaa and Tlae thymocytes, which are closely related serologically, were broadly similar, but clearly different from the pattern typical of Tlac and Tlad thymocytes. 2D peptide maps of TL from Tlaa thymocytes and Tlaa leukemia cells did not differ. Leukemia cells of Tlab origin (thymocytes TL-) gave 2D peptide and 2D IEF-SDS-PAGE patterns of a third type. With the exception of Tlaa, thymocytes of TL+ mice yielded additional TL products of higher molecular weight than the TL H chain.
Amino acid sequence analysis of human interleukin 1 (IL-1). Evidence for biochemically distinct forms of IL-1.
Authors: Cameron P , Limjuco G , Rodkey J , Bennett C , Schmidt J A
Published: June 2004

The pI-6.8 species of normal human interleukin 1 (IL-1) has been isolated by ion-exchange and reverse-phase high-performance liquid chromatography. The isolated material had a molecular weight of 18,000, and had a specific bioactivity of 1.7 X 10(7) half-maximal U/mg in the murine thymocyte proliferation assay, values similar to those obtained for murine P388D1-derived IL-1 (12), and human IL-1 isolated by a previously published purification protocol (15). Amino-terminal sequence analysis revealed a single N-terminal, and resulted in the identification of 30 of the first 35 amino acid residues. Sequence of three CNBr cleavage fragments of purified IL-1 resulted in the identification of an additional 38 residues. All of the sequences agree exactly with those deduced from complementary DNA (cDNA) by Auron, et al. (18), demonstrating that this cloned cDNA, though considerably different from the cDNA reported for murine IL-1 (12), nevertheless codes for the pI-6.8 species of human IL-1. The evidence also shows that the precursor protein for human IL-1 is largely processed at the N-terminal end. Little or no processing occurs at the carboxy-terminal end. Sequence homology with interferon-inducing factor (26) suggests that the pI-6.8 species of human IL-1 is a member of a gene family. Although equally potent in the murine thymocyte proliferation assay, murine IL-1 and the pI-6.8 species of human IL-1 are structurally distinct. Further study will answer the interesting question as to the relationship of the other charged species of human IL-1 to these distinct IL-1 classes.
IgG bearing covalently bound C3b has enhanced bactericidal activity for Escherichia coli 0111.
Authors: Joiner K A , Fries L F , Schmetz M A , Frank M M
Published: June 2004

The mechanism was sought by which bactericidal IgG for E. coli 0111 (strain 12015) increases the bactericidal efficiency of C5b-9. IgG did not affect the distribution of C3 deposition on the O-Ag capsule and the outer membrane of 12015, suggesting that bactericidal IgG was not directing complement activation to different sites on the bacterial surface. However, one-fifth of the C3 that was deposited in the presence of IgG attached covalently to the antibody molecule. Covalent complexes between purified C3b and IgG were prepared in order to study the role of C3b-IgG in the bactericidal reaction. 8-10-fold less C3b-IgG than IgG was necessary to sensitize 12015 for serum killing. When aggregates were eliminated from the C3b-IgG and IgG preparations by sucrose density gradient ultracentrifugation, C3b-IgG remained three- to fourfold more effective than IgG on a molecule-for-molecule bound basis in mediating the serum bactericidal reaction. These results suggest that formation of C3b-IgG during the serum bactericidal reaction is critical for killing, and have important implications for the development of effective bactericidal vaccines.
The cell surface molecule recognized by the erythrocyte receptor of T lymphocytes. Identification and partial characterization using a monoclonal antibody.
Authors: Hünig T
Published: June 2004

A monoclonal antibody (mAb) to sheep red blood cells (SRBC), termed L180/1, is described that completely blocks rosette formation between SRBC and human or sheep T lymphocytes. L180/1 precipitated a minor glycoprotein of about approximately 42,000 mol wt from surface-labeled SRBC. This glycoprotein was partially affinity purified and found to block E rosette formation and to compete with anti-T11 mAb for the E receptor. The molecule detected by mAb L180/1 thus appears to be recognized by the E receptor and was given the preliminary name, T11 target structure (T11TS). Since the mAb to sheep T11TS blocks the binding of SRBC to both human and sheep T cells, and mAb to T11 blocks the binding of red cells from human and sheep to the human E receptor, we concluded that analogous receptor-ligand (T11-T11TS) systems exist in man and sheep that are crossreactive over the species barrier. The possibility is discussed that the E receptor, which is known to be involved in T cell activation, and T11TS function as complementary cell interaction molecules in T cell responses.