bluuebunny/crossref_metadata_2025 huggingface dataset:
Pili of Neisseria meningitidis. Analysis of structure and investigation of structural and antigenic relationships to gonococcal pili.
Authors: Stephens D S , Whitney A M , Rothbard J , Schoolnik G K
Published: June 2004

To provide information useful for the design of a pilus vaccine effective for the prevention of both meningococcal and gonococcal disease, the electron microscopic morphology of meningococcal pili and the structural and antigenic relationships of meningococcal pili to gonococcal pili were investigated. Meningococcal pili were 4-6 nm in width, extended 500-6,000 nm from the organism surface, and occurred singly or in bundles composed of 8-10 pili per bundle. Meningococcal pilin varied between 17,250 and 20,600 daltons. Pilin was present in outer membrane preparations of some meningococcal isolates that were nonpiliated by electron microscopic examination. Antibodies to gonococcal pili, cyanogen bromide cleavage fragments of gonococcal pilin, or synthetic peptide analogues corresponding to regions of the gonococcal pilin sequence, were used to detect common meningococcal and gonococcal antigenic determinants that might indicate the existence of a conserved sequence beyond residue 29. Antibody to intact gonococcal pili or to the variable CNBR-3 region of gonococcal pilin detected little shared antigenicity with meningococcal pilin. However, pilin from all tested meningococcal isolates reacted with antibody to the CNBR-2 fragment of gonococcal pilin, a region highly conserved among gonococcal strains. Meningococcal pilins were also broadly crossreactive with antibody to a synthetic peptide corresponding to residues 69-84 of the gonococcal sequence, a part of the CNBR-2 region that appears to be critical for gonococcal receptor-binding function. If a sequence similar to 69-84 is also important for receptor-binding function in meningococcal pili, a peptide corresponding to this region may elicit antibodies that block the adherence function of pili elaborated by both Neisseria gonorrhoeae and N. meningitidis.
Progenitors for Ly-1 B cells are distinct from progenitors for other B cells.
Authors: Hayakawa K , Hardy R R , Herzenberg L A , Herzenberg L A
Published: June 2004

Data from previous multiparameter fluorescence-activated cell sorter (FACS) analysis and sorting studies define a subset of murine B cells that expresses the Ly-1 surface determinant in conjunction with IgM, IgD, Ia, and other typical B cell markers. These Ly-1 B cells are physically and functionally distinct. They express more IgM and less IgD than most other B cells; they are not normally found in lymph node or bone marrow; they are always present at low frequencies (1-5%) in normal spleens, and, as we show here, they comprise about half of the B cells (10-20% of total cells) recovered from the peritoneal cavity in normal mice. Furthermore, most of the commonly studied IgM autoantibodies in normal and autoimmune mice are produced by these Ly-1 B cells, even though they seldom produce antibodies to exogenous antigens such as trinitrophenyl-Ficoll or trinitrophenyl-keyhole limpet hemocyanin. Cell transfer studies presented here demonstrate that the progenitors of Ly-1 B cells are different from the progenitors of the predominant B cell populations in spleen and lymph node. In these studies, we used FACS analysis and functional assays to characterize donor-derived (allotype-marked) B cells present in lethally irradiated recipients 1-2 mo after transfer. Surprisingly, adult bone marrow cells typically used to reconstitute B cells in irradiated recipients selectively failed to reconstitute the Ly-1 B subset. Liver, spleen, and bone marrow cells from young mice, in contrast, reconstituted all B cells (including Ly-1 B), and peritoneal "washout" cells (PerC) from adult mice uniquely reconstituted Ly-1 B. Bone marrow did not block Ly-1 B development, since PerC and newborn liver still gave rise to Ly-1 B when jointly transferred with marrow. These findings tentatively assign Ly-1 B to a distinct developmental lineage originating from progenitors that inhabit the same locations as other B cell progenitors in young animals, but move to unique location(s) in adults.
Identification, at the genomic level, of an HLA-DR restriction element for cloned antigen-specific T4 cells.
Authors: Paulsen G , Qvigstad E , Gaudernack G , Rask L , Winchester R , Thorsby E
Published: June 2004

Two T4 cell clones (TLC) specific for antigenic epitopes on Chlamydia trachomatis were studied. Using a panel of allogeneic antigen-presenting cells (APC), both TLC were found to be restricted by HLA class II elements closely associated with, but not identical to the DRw5S specificity, as determined by highly selected alloantisera, a monoclonal antibody (mAb), 109d6, and confirmed on the DNA level by determination of restriction fragment length polymorphisms (RFLP) with a DR beta probe. Furthermore, HLA-DR-specific mAb, including 109d6, but not other HLA class II- or class I-specific antibodies inhibited the two TLC, strongly suggesting that the restriction element is expressed by a DR molecule. Using digestion with Hind III restriction enzyme and a DR beta probe, we found a complete concordance between the appearance of a 9.3 kilobase band and the ability of allogeneic APC to restimulate the T cell clones. Thus, the restriction element for these T cell clones appear to be expressed by DR molecules, but can, at present, only be detected at the genomic level.
Prolonged survival in vivo of unprimed B cells responsive to a T-independent antigen.
Authors: Ron Y , Sprent J
Published: June 2004

Despite earlier evidence to the contrary, it has recently been claimed that most B lymphocytes, including lymph node (LN) and thoracic duct B cells, are short-lived cells of recent marrow origin. To seek direct information on this question, we transferred unprimed LN or thoracic duct B cells from normal mice to xid mice, i.e., mice unresponsive to the T-independent antigen, trinitrophenyl (TNP)-Ficoll. At varying periods after B cell transfer the recipients were challenged with TNP-Ficoll; anti-TNP plaque-forming cells were assayed in the spleen 6 d later. The results showed that the B cell recipients retained responsiveness to TNP-Ficoll for at least 3 mo after transfer. Responsiveness increased within the first 3 wk but then remained relatively constant. These findings imply that, at least for TNP-Ficoll-reactive cells, B cells residing in LN and thoracic duct lymph are not short-lived cells of recent marrow. Indeed, the data suggest that once the pool of recirculating B cells is fully formed in adult mice, further input of newly formed cells from the marrow into the recirculating pool is very limited.
Authentic T helper CD4 (W3/25) antigen on rat peritoneal macrophages.
Authors: Jefferies W A , Green J R , Williams A F
Published: June 2004

The rat W3/25 antigen that appears to be equivalent to human CD4 (T4) antigen is expressed on thymocytes and T helper cells and plays a role in the response of T helper cells to antigen. The W3/25 and anti-T4 antibodies also label macrophages. In this paper we examine whether the macrophage antigen is the same as that on T cells. New monoclonal antibodies against the rat CD4 antigen, MRC OX-35 through OX-38, are described, all of which label peritoneal macrophages from normal and athymic rats. The molecular weight of W3/25 antigen on macrophages is indistinguishable from that on T cells. We conclude that macrophages express authentic CD4 (W3/25) antigen. Another new monoclonal antibody, MRC OX-34, labels an antigen of 50-54,000 mol wt that is expressed on rat T but not B cells or peritoneal macrophages. It was used to control for the presence of any T cell products in immunoprecipitation from rat macrophage extracts.
Differential requirements of B cells from normal and allergic subjects for the induction of IgE synthesis by an alloreactive T cell clone.
Authors: Umetsu D T , Leung D Y , Siraganian R , Jabara H H , Geha R S
Published: June 2004

Human T cell helper/inducer clones were used to induce IgE synthesis in B cells from both allergic and nonallergic donors. An alloreactive T cell clone, activated by recognition of specific HLA-DR antigens, stimulated peripheral blood B cells from both allergic and nonallergic donors to synthesize IgE antibody. B cells of allergic donors differed from those of nonallergic donors in their requirements for induction of IgE synthesis. Induction of IgE synthesis in B cells from nonallergic individuals occurred only under conditions of cognate interaction, in which the B cells expressed the alloantigen recognized by the T cells. In contrast, IgE synthesis in B cells from allergic donors occurred under conditions of cognate interaction with T cells as well as bystander conditions where the B cells did not express the alloantigen recognized by the T cell clones and where the T cell clones were stimulated by third-party monocytes bearing the relevant alloantigens. Furthermore, bystander stimulation of IgE synthesis in allergic donors occurred in the presence of tetanus toxoid (TT) antigen-specific T cell clones activated by the appropriate TT-pulsed monocytes. In contrast to the differing requirements of B cells from normal vs. allergic subjects for the induction of IgE synthesis, these B cells did not differ in their requirements for the induction of IgG synthesis. IgG synthesis was induced in all B cells under conditions of cognate interaction with the T cells as well as under conditions of bystander stimulation. These results suggest that cognate T-B cell interactions may be important in the development of IgE immune responses in the normal host.
Characterization of mixed allogeneic chimeras. Immunocompetence, in vitro reactivity, and genetic specificity of tolerance.
Authors: Ildstad S T , Wren S M , Bluestone J A , Barbieri S A , Sachs D H
Published: June 2004

Mixed allogeneically reconstituted mice (B10 + B10.D2----B10) that specifically accept B10.D2 tail skin allografts were examined for in vivo and in vitro immunocompetence, patterns of hematopoietic repopulation, and in vitro reactivity. In vitro, mixed allogeneic chimeras (B10 + B10.D2----B10) manifested specific tolerance in mixed lymphocyte reactions and cell-mediated lympholysis to B10 and B10.D2 splenocytes, with normal responses to third-party (B10.BR) cells. Such chimeras were immunocompetent in B cell and helper T cell responses, as assessed by their primary plaque forming cell responses to in vivo sheep red blood cell immunization. This is in contrast to fully allogeneic chimeras, which responded less well. In addition, survival of the mixed allogeneic chimeras in a conventional animal facility was superior to that of fully allogeneic chimeras, and similar to syngeneically reconstituted (B10----B10) mice. Specific tolerance to skin grafts, degree of allogeneic engraftment, and persistence of chimerism was also assessed in a noncongenic mixed allogeneic combination (B10 + C3H----B10). Such animals manifested specific hyporeactivity to C3H skin allografts, but eventual chronic rejection of the grafts occurred in spite of stable and persistent mixed chimerism. MHC-congenic (B10.BR) skin grafts were accepted indefinitely in the same animals, suggesting that skin-specific non-major histocompatibility complex antigens were responsible for rejection of the C3H skin allografts.
Cloned natural suppressor cell lines derived from the spleens of neonatal mice.
Authors: Schwadron R B , Gandour D M , Strober S
Published: June 2004

The establishment and characterization of cloned natural suppressor (NS) cell lines derived from the spleen of neonatal BALB/c mice are described. Cloned NS cells suppress the mixed leukocyte reaction (MLR) between normal adult responder and stimulator spleen cells with a 50-fold greater efficiency than fresh neonatal cells. Suppressive activity of both cells did not depend on the haplotype of the responder or stimulator cells, and was radioresistant. Cloned NS cells did not inhibit the uptake of [3H]thymidine by HT-2 cells proliferating in response to interleukin 2 (IL-2), nor the in vitro secretion of IL-1 by macrophages in response to lipopolysaccharide. Several experiments indicated that absorption of IL-2 could not explain the suppression of the MLR by the NS cells in the range of cell numbers tested. The results suggest that NS cells may suppress the MLR by interfering with early stages of T cell activation. The cell surface of a cloned NS cell line was examined using immunofluorescence staining, and was strongly positive for the Thy-1.2, Ly-5, and asialo-GM1 antigens. However, Lyt-1, Lyt-2, surface Ig, IE, MAC-1, and Fc and C3 receptor markers were not detected. In addition, NS cells showed no cytolytic activity against the YAC-1 target cell line. On the basis of these findings, cloned NS cells do not appear to be mature T cells, B cells, macrophages, or NK cells. The development of cloned NS cells may be useful in determining the identity and mechanism of action of nonspecific suppressor cells in the neonatal spleen, and their role in neonatal tolerance and maternal-fetal relationships.
Macrophage complement and lectin-like receptors bind Leishmania in the absence of serum.
Authors: Blackwell J M , Ezekowitz R A , Roberts M B , Channon J Y , Sim R B , Gordon S
Published: June 2004

We have examined the relative roles of the macrophage (M phi) plasma membrane receptor for the cleaved third complement component (iC3b, CR3) and of the mannosyl/fucosyl receptor (MFR) in binding and ingestion of Leishmania donovani. In the absence of exogenous complement, the binding and ingestion of promastigotes, which are good activators of the alternative complement pathway, were inhibited by the anti-CR3 monoclonal antibody M1/70, by the Fab portion of an anti-C3 antibody, or by the nucleophile, sodium salicyl hydroxamate, an inhibitor of C3 fixation. This provides strong evidence that M phi-derived, cleaved C3 (iC3b) present on the promastigote surface mediates binding to CR3. Equivalent inhibition of promastigote binding and ingestion was also observed using the soluble inhibitors of MFR activity, mannan or ribonuclease B. No additive effect for blocking the two M phi receptors simultaneously was observed. For amastigotes, which are poor activators of the alternative pathway, a lesser but nevertheless equivalent effect was observed for the three soluble inhibitors of CR3-mediated binding vs. the two soluble inhibitors of MFR-mediated binding. Modulation experiments in which either CR3 or MFR had been rendered inaccessible demonstrated that both receptors must be present on the segment of M phi membrane to which the parasite binds. The combined function of these two distinct M phi receptors may provide a general mechanism for recognition and ingestion of other pathogenic protozoa known to activate the alternative pathway.
Major histocompatibility complex restriction fragment length polymorphisms define three diabetogenic haplotypes in BB and BBN rats.
Authors: Buse J B , Rifai-Haddad R , Lees S , Taniguchi H , Chaplin D , Milford E M , Seidman J G , Eisenbarth G S , Jackson R A
Published: June 2004

Class I and II major histocompatibility complex (MHC) probes can be used to subdivide diabetes-prone BB rats and their BBN control strain, coderived from the same outbred colony by selection against diabetes. Class II probes (A-alpha in particular) distinguish four restriction fragment length polymorphisms (RFLP), termed 1a, 1b, 2a, and 2b, in the BBN population, only one of which (2a) is found in BB rats. The degree of class II RFLP in the population studied is RT1.B-alpha greater than or equal to RT1.B-beta greater than RT1.D-alpha greater than or equal to RT1.D-beta, suggesting that intra-class II region dynamics may be different in rats compared with mice. A class I probe (S16) absolutely distinguished BB from BBN rats, since all BB rats exhibit an RFLP pattern termed 2a0, while 2a BBN rats can be subdivided into 2a1 and 2a2 forms. Serologic evaluation has shown that 2a0, 2a1, and 2a2 rats express RT1.AuBu, 1a rats express RT1.AaDa, and 1b rats express neither RT1a nor RT1u at the loci tested. A breeding study was carried out to determine the diabetogenicity of the MHC-defined RFLP's. As expected, the BB-derived 2a0 is diabetogenic. The BBN-derived 2a1 and 2a2 RFLPs are also diabetogenic, while 1a and 1b rats do not carry MHC-linked diabetogenic genes. The MHC-linked diabetes gene acts in a functionally recessive manner, since there is a 10-fold higher incidence in homozygotes than in heterozygotes. Analysis of the RFLP patterns leads us to hypothesize that the 2a1 RFLP results from a crossover between 1a and 2a0 MHCs and that the diabetogenic MHC-linked gene is on the class II side of Qa and T1. The availability of three diabetogenic MHC haplotypes should help localize the MHC-linked diabetogenic gene of rats.
Human natural anti-alpha-galactosyl IgG. II. The specific recognition of alpha (1----3)-linked galactose residues.
Authors: Galili U , Macher B A , Buehler J , Shohet S B
Published: June 2004

A natural IgG antibody (anti-Gal) with alpha-galactosyl binding specificity has been found in large amounts (0.5 - 1.0% of serum IgG) in all individuals tested. It has been purified by affinity chromatography on a column of melibiose-Sepharose. In addition to its affinity for normal and pathological senescent human red cells, the antibody readily interacts with rabbit red blood cell (RRBC) glycolipids with alpha-galactosyl terminal residues. Two types (glycosidic linkages of 1----3 vs. 1----4) of rabbit red cells glycolipids with terminal alpha-galactosyl residues were tested for antibody binding. The antibody specifically bound to glycolipids with Gal alpha 1----3 terminal residues, and treatment of these glycolipids with alpha-galactosidase abolished binding. Hemagglutination inhibition studies with oligosaccharides of known structure also showed that the antibody binds specifically to glycoconjugates with an alpha 1----3 terminal galactose residue. Anti-Gal did not bind to a human B-active glycolipid, indicating that fucose-linked alpha 1----2 to the penultimate galactose prevents anti-Gal binding. The anti-Gal specificity for RRBC glycolipids also paralleled that of the alpha-galactosyl-specific Bandeiraea simplicifolia lectin. The possible reasons for the occurrence of this unique antibody in human serum are discussed.
Allorestricted cytotoxic T cells. Large numbers of allo-H-2Kb-restricted antihapten and antiviral cytotoxic T cell populations clonally develop in vitro from murine splenic precursor T cells.
Authors: Reimann J , Kabelitz D , Heeg K , Wagner H
Published: June 2004

Cytotoxic T lymphocyte (CTL) responses of splenic T cells from C57BL/6 B6) mice and mutant H-2Kbm1 (bm1) mice to haptenic (trinitrophenyl [TNP] ) and herpes simplex virus (HSV) determinants in the context of an allogenic (wild-type or mutant) H-2Kb molecule were analyzed in a modified limiting dilution system. In the B6-anti-bm1TNP mixed leukocyte reaction (MLR), estimated frequencies for precursors of CTL clones that lysed bm1TNP targets ranged from 1/120 to 1/400; in the bm1-anti-B6TNP MLR, estimated frequencies of precursors of CTL clones that lysed B6TNP targets ranged from 1/500 to 1/1,300. Estimated frequencies for precursors of CTL clones that lysed the respective unmodified and TNP-modified allogeneic targets were two- to three-fold lower. Lytic specificity patterns determined by split-well analysis showed that at least 20-30% of the generated CTL populations (selected for a high probability of clonality) in both MLR displayed allorestricted lysis of TNP-modified concanavalin A blast targets. In the B6-anti-bm1HSV MLR, estimated frequencies for precursors of CTL clones that lysed bm1HSV targets ranged from 1/70 to 1/300; in the bm1-anti-B6HSV MLR, estimated frequencies for precursors of CTL clones that lysed B6HSV targets ranged from 1/300 to 1/1,200. Again, estimated frequencies for precursors of CTL clones that lysed the respective noninfected and virus-infected allogeneic targets were two- to fourfold lower. Of the CTL populations selected for a high probability of clonality at least 30-60% displayed allorestricted lysis of virus-infected lipopolysaccharide blast targets in both MLR. It is concluded that a large fraction of clonally developing CTL populations stimulated with TNP-modified or HSV-infected allo-H-2Kb-bearing cells displayed an allorestricted pattern of recognition. It was further evident that the estimated frequencies of splenic precursors that generated allorestricted CTL clones was two- to threefold higher than the estimated frequencies of precursors that gave rise to the respective alloreactive CTL populations.
Dendritic cells that have interacted with antigen are targets for natural killer cells.
Authors: Shah P D , Gilbertson S M , Rowley D A
Published: June 2004

Natural killer (NK) cells (poly I:C induced, x-ray resistant, nonadherent, Thy-1-, Ly-1.1-, Ly-2.1-, anti-asialo GM1-positive, and cytotoxic for YAC-1) suppressed T lymphocyte proliferation in mixed lymphocyte reaction (MLR) and autologous MLR cultures. Dendritic cells (DC) were required for proliferation of lymphocytes in both responses. The question whether lymphocytes or DC were the targets for NK cells was resolved by taking advantage of the fact that NK cells, but not DC, lose activity after 24 h in culture. Three findings indicate that DC, not lymphocytes, are targets for NK cells. First, responses suppressed by NK cells were fully restored by adding small numbers of DC to cultures 24 h after NK cells had been added. Second, DC incubated alone with NK cells and antigen for 24 h did not stimulate proliferation of lymphocytes. Third, lymphocytes incubated alone with NK cells for 24 h proliferated normally when DC were added. Additional experiments showed that DC became targets only after interaction with antigen. Thus, we suggest that NK cells may regulate lymphocyte proliferation by monitoring antigen presentation by DC.
Immunochemical and molecular characterization of regulatory idiotopes expressed by monoclonal antibodies exhibiting or lacking beta 2-6 fructosan binding activity.
Authors: Victor-Kobrin C , Bonilla F A , Bellon B , Bona C A
Published: June 2004

Hybridomas secreting antibodies bearing the ABPC48 (A48) regulatory idiotype (Id) were generated from BALB/c mice treated at birth or as adults with minute amounts of anti-A48-Id antibodies. The majority of these antibodies were recognized by the syngeneic monoclonal anti-A48-Id and anti-UPC-10-Id antibodies, IDA10 and 10-1, respectively. In Northern blotting experiments, most of these hybridomas were shown to use VH (heavy chain variable region) genes related to the 441-4 germline VH gene that encodes the A48 VH region. Hybridization was detected between polyadenylated H chain mRNA, isolated from the majority of the hybridomas, and the VH probe. Southern blots confirmed these results by showing a rearrangement of VH-related sequences to the JH (H chain joining segment) clusters on these same hybridomas. The antibodies from all of the hybridomas that derived from neonatal mice and half of those derived from adult mice showed specificity for fructosan determinants that, in most cases, was different from the beta 2-6 fructosan linkage specificity of A48. Surprisingly, several of the non-fructosan-binding hybridomas generated from the adult mice and the MOPC-173 myeloma demonstrated a clear specificity for the beta 1-6-D-galactan determinant. Of four galactan-binding myeloma proteins studied. XRPC 44 alone shared idiotypy with the UPC-10 myeloma. These findings suggest a possible clonal crossreactive regulation mediated by regulatory idiotopes. The crossreactive regulation concept is discussed.
Pilus- gonococcal variants. Evidence for multiple forms of piliation control.
Authors: Swanson J , Bergström S , Barrera O , Robbins K , Corwin D
Published: June 2004

Pilus+ to pilus- transitions of gonococci (Gc) that involve rearrangement of pilin gene DNA yield the P-n phenotype, which is incapable of reversion (to pilus+). Reversion to pilus+ is found for nonpiliated Gc that have undergone no apparent pilin gene rearrangement. Among the reverting, nonpiliated Gc, two distinct phenotypes (P-rp- and P-rp+) occur and are differentiated according to their synthesis (or lack) of pilin subunits; both P-rp- and P-rp+ Gc contain pilin-specific mRNA. The occurrence of these different pilus- phenotypes strongly suggests that several mechanisms can account for changes in the piliation status of Gc; one of these involves pilin gene rearrangement but the others apparently operate at posttranscriptional levels. Reverting pilus- Gc may have a pathogenic advantage in being able to reversibly alter their host cell adherence-promoting surface properties through high frequency transitions in piliation status.
Antigen valence determines the binding of nominal antigen to cytolytic T cell clones.
Authors: Siliciano R F , Colello R M , Keegan A D , Dintzis R Z , Dintzis H M , Shin H S
Published: June 2004

We have shown that cytotoxic T cell clones specific for the nominal antigen FL will bind high molecular weight (600,000 to 2,000,000) polyacrylamide and Ficoll polymers conjugated with 200-600 FL groups per molecule. Low molecular weight polymers (40,000) with the same epitope density did not give stable binding. A high molecular weight polymer with a lower epitope density also failed to bind. Taken together, these results suggest that a substantial degree of multivalence is a necessary factor in the stable binding of nominal antigen to T cell clones.
Localization of the ring-infected erythrocyte surface antigen (RESA) of Plasmodium falciparum in merozoites and ring-infected erythrocytes.
Authors: Brown G V , Culvenor J G , Crewther P E , Bianco A E , Coppel R L , Saint R B , Stahl H D , Kemp D J , Anders R F
Published: June 2004

Immunoelectron microscopy with protein A gold has been used to determine the subcellular location of the ring-infected erythrocyte surface antigen (RESA) of Plasmodium falciparum. RESA was associated with dense vesicles presumed to be micronemes within merozoites. RESA was not detected on the surface of merozoites but was located at the membrane of erythrocytes infected with ring-stage parasites. RESA within merozoites was largely soluble in the nonionic detergent Triton X-100, but was insoluble in this detergent when associated with the erythrocyte membrane.
Lymphoid tumors displaying rearrangements of both immunoglobulin and T cell receptor genes.
Authors: Pelicci P G , Knowles D M , Dalla Favera R
Published: June 2004

Ig and T beta gene rearrangements can be used as genetic markers of lineage and clonality in the study of B and T cell populations. We have addressed the issue of the respective B and T lineage specificity of these rearrangements by analyzing a panel of 63 lymphoid tumors representative of the various clinicopathologic categories of both B and T neoplasias. We report that approximately 10% of the cases tested displayed rearrangements of both Ig and T beta genes. Despite their dual genotypic pattern, these tumors retain a pure immunophenotype, i.e. they display either B or T cell lineage-restricted cell surface antigens. The implications of these findings for both normal and neoplastic lymphoid differentiation are discussed.
High incidence of B cell lymphomas derived from thymectomized AKR mice expressing TL.4 antigen.
Authors: Peled A , Haran-Ghera N
Published: June 2004

AKR mice, 6-12 mo after birth, display a high incidence of spontaneous T cell lymphomas that can be prevented by thymus removal at the age of 1-3 mo. We report here the presence of dormant preleukemic cells among bone marrow cells of 8-12-mo-old AKR mice that have been thymectomized when 40-60 d old. Transplantation of bone marrow cells from these thymectomized AKR donors into syngeneic or hybrid (AKR X DBA/2)F1 intact or thymectomized recipients resulted in lymphoma development of AKR origin in 80-100% of the recipients. Analysis, by flow microfluorometry, of the antigenic cell surface phenotypes of the developing lymphomas revealed that all tumors were B cell lymphomas, since the cells stained with class-specific anti-IgM reagents and other reagents specific for B cells (RA3-2C2, RA3-6B2, anti-I-A, and anti-Fc receptor), and were Thy-1-. All these B cell tumors also expressed two T cell differentiation antigens, TL.4, found exclusively on T cell lymphomas, and Lyt-1 antigen, previously shown (11) to be expressed on some B cell neoplasms. The surface markers mu, I-A, RA3-2C2, and TL.4 identified by immunofluorescence, were shown to be integral membrane components synthesized by the tumor cells, rather than passively acquired proteins.
Restriction fragment length polymorphism of the gene encoding the alpha chain of the human T cell receptor.
Authors: Hoover M L , Marks J , Chipman J , Palmer E , Stastny P , Capra J D
Published: June 2004

Two allelic forms of the T cell antigen receptor alpha chain gene were discerned by restriction fragment length polymorphism (RFLP) employing the T cell antigen receptor alpha chain probe pGA5, and the restriction enzyme Bgl II. Analysis revealed that the polymorphic fragments are detected by a probe specific for the constant region exon of the T cell antigen receptor alpha chain gene. Furthermore, the polymorphic fragments were shown to segregate within families. The two allelic forms yield two homozygous states, 3.2/3.2 and 2.9/2.9, at a frequency of 76.5 and 2.9%, respectively, within the normal population. The heterozygous state was observed in 20.6% of the population. The discovery of allelic forms of both the alpha and beta chains of the T cell antigen receptor genes may provide a unique opportunity to study heritable markers of T cell function in several human diseases.
Involvement of T44 molecules in an antigen-independent pathway of T cell activation. Analysis of the correlations to the T cell antigen-receptor complex.
Authors: Moretta A , Pantaleo G , Lopez-Botet M , Moretta L
Published: June 2004

Prior studies indicate that the 9.3 monoclonal antibody (mAb) which defines a 44 kD T lineage-specific glycoprotein (T44) enhances the proliferative response of peripheral blood T lymphocytes to phytohemagglutinin (PHA) or allogeneic cells. The T44 molecule was expressed in both resting and activated T lymphocytes and in a subset of thymocytes, as assessed by indirect immunofluorescence and flow cytofluorometry. In view of the potential importance of T44 in T cell activation, we investigated the ability of the 9.3 (anti-T44) antibody to stimulate peripheral blood T lymphocytes under culture conditions giving optimal proliferative responses to anti-T3 mAb. Like UCHT1 (anti-T3) mAb, the 9.3 (anti-T44 mAb) promoted strong proliferative responses of purified T cells, provided that adherent cells were added to the culture. Maximal proliferation in response to 9.3 antibody was consistently detected at day 5 (at day 3 with anti-T3 or PHA). Moreover, triggering of T lymphocytes with 9.3 antibody (in the presence of adherent cells) resulted in strong IL-2 production that peaked at 48 h. Analysis of the physical and functional relationship between the T44 molecule and other molecules involved in T cell activation, including the clonotypically restricted Ti and the monomorphic T3 or T11 molecules, was carried out on a mutagenized jurkat T leukemia cell line. This mutant, termed JA3 (surface phenotype: T11+, T3+, 3A1+, T4-, T8-, DR-, Tac-, 4F2+, T44+) produced large amounts of IL-2 upon stimulation with PHA, anti-T3, or anticlonotypic mAb in conjunction with phorbol myristate acetate (or adherent cells). The molecules precipitated by anti-T44 mAb from 125I-labeled JA3 cells appeared as a diffuse band of Mr 40-45,000 under reducing conditions; under nonreducing conditions, a prominent band of Mr 80-85,000 was observed, while the Mr 40-45,000 band was greatly reduced. Thus, T44 molecules in both reducing and nonreducing conditions had relative molecular weights similar to that of molecules carrying clonotypic (Ti) determinants. In addition, like anti-Ti or anti-T3 mAb, anti-T44 antibody induced JA3 cells to produce large amounts of IL-2 in the presence of phorbol myristate acetate. Other similarities between T44 and molecules carrying clonotypic structures included the susceptibility to antibody-induced modulation and the late reexpression (72 h) at the cell surface after modulation. Taken together, these experiments suggest that anti-T44 mAb might recognize a monomorphic determinant of the T cell receptor molecule or be physically or functionally linked to the T3-Ti complex.(ABSTRACT TRUNCATED AT 400 WORDS)
Characterization of antigen-specific, Ia-restricted, L3T4+ cytolytic T lymphocytes and assessment of thymic influence on their self specificity.
Authors: Golding H , Munitz T I , Singer A
Published: June 2004

The goals of the present study were: (a) to generate antigen-specific L3T4+ cytolytic T lymphocytes (CTL), (b) to determine their major histocompatibility complex (MHC) restriction specificity, and (c) to assess the influence of thymic MHC determinants on their self specificity. We found that L3T4+ CTL specific for either trinitrophenyl (TNP)-modified self determinants or minor histocompatibility antigens could be generated from Lyt-2- responder T cells provided that the response cultures were supplemented with supernatants rich in helper factors. Such antigen-specific L3T4+ CTL were Ia-restricted by the criteria that they lysed only Ia+ target cells and that their lysis of Ia+ target cells was specifically inhibited by anti-Ia monoclonal antibodies. The relative frequency of L3T4+ pCTL was found to be only 5-10% of the total anti-TNP pCTL present in the spleens of normal mice. Finally, we utilized radiation bone marrow chimeras to assess the influence of the thymic haplotype on the self-Ia specificity of L3T4+ CTL. Both bulk culture and limiting dilution experiments revealed that the self-Ia specificity of L3T4+ anti-TNP CTL from F1----parent and A----B allogeneic chimeras was not markedly skewed toward the haplotype of the chimeric thymus. These results contrast with those obtained previously for L3T4+ anti-TNP Th cells and demonstrate that in the radiation bone marrow chimera model of T cell differentiation, the self specificity of Th cells but not pCTL is markedly influenced by the haplotype of the chimeric thymus.
Decay-accelerating factor is present on paroxysmal nocturnal hemoglobinuria erythroid progenitors and lost during erythropoiesis in vitro.
Authors: Moore J G , Frank M M , Müller-Eberhard H J , Young N S
Published: June 2004

A glycoprotein that regulates the deposition of C3b on the erythrocyte surface, called decay-accelerating factor or DAF, is absent from the red blood cells (RBC) of patients with paroxysmal nocturnal hemoglobinuria (PNH), explaining in part their abnormal sensitivity to complement. We used a specific antiserum to DAF, flow microfluorometry, and clonogenic assays for erythroid progenitor cells to study PNH erythropoiesis in vitro. By fluorescence-activated cell sorter analysis, all RBC from normal individuals are DAF+. In contrast, the RBC of six patients with PNH showed discrete populations of DAF- cells (10-44%; x +/- SEM = 31 +/- 6%). The DAF- RBC population was partly eliminated by prior acidified serum lysis. To determine whether erythropoietic progenitors expressed DAF, bone marrow cells were sorted by flow microfluorometry and the separated DAF+ and DAF- populations then cultured in vitro. In two normal individuals, but also in six patients with PNH, erythroid colonies formed only from cells in the DAF+ fraction. However, a variable proportion of the normoblast progeny of these DAF+ progenitor cells from patients with PNH was DAF-. Individual bursts removed from cultures of PNH bone marrow showed two discrete populations by fluorescence; the majority of normoblasts were DAF-, only 3 of 27 individual bursts had greater than 50% DAF+ cells, and in three patients, DAF- normoblasts averaged 79%. In contrast, the progeny of individual bursts from normal individuals comprised a unimodal DAF+ population. In each PNH patient, one normal burst (greater than 80% DAF+ normoblasts) was detected, possibly reflecting a normal residual population of erythroid progenitors. By the criterion of DAF expression, there was no evidence of separate populations of normal and PNH type progenitor cells. The phenotypically normal erythroid progenitors of PNH bone marrow acquire the PNH characteristics during differentiation in vitro.
Direct evidence that a class II molecule and a simple globular protein generate multiple determinants.
Authors: Allen P M , McKean D J , Beck B N , Sheffield J , Glimcher L H
Published: June 2004

We have examined the individual contributions of the I-A kappa alpha chain, the I-A kappa beta chain, and the foreign antigen hen egg-white lysozyme (HEL) in the formation of the determinant being recognized by the T cell receptor. As functional probes we have used (a) a panel of 10 HEL-specific T cell hybridomas, (b) a panel of antigen-presenting cells (APC) possessing mutations in either the I-A kappa alpha or I-A kappa beta chains, and (c) proteolytic fragment of HEL and related synthetic peptides. The ability of the I-A kappa beta and I-A kappa alpha mutant cell lines to present antigen to the 10 T cell hybridomas divided these T cells into six distinct groups. These HEL-specific T cells therefore appear to recognize several distinct domains on the I-A kappa molecule. The 10 T cell hybrids were then shown to recognize at least three distinct determinants on the HEL molecule, with 8 of the 10 hybrids recognizing one of two major determinants HEL(46-61) or HEL(34-45). Combining the response patterns to the panel of I-A kappa mutant APC lines with the antigen specificity revealed that the 10 T cell hybrids recognized at least eight unique determinants formed by the I-A kappa alpha chains, I-A kappa beta chains, and HEL peptides. This analysis provides direct evidence that a large number of different determinants or T cell receptor ligands can be generated from a single Ia molecule and a simple globular protein.
Perturbation of the T4 molecule transmits a negative signal to T cells.
Authors: Bank I , Chess L
Published: June 2004

We investigated the functional role of the T4 molecule in the activation of T cells by OKT3. T4+ cells were induced to proliferate by OKT3 and erythrocyte rosette-negative accessory cells in the presence or absence of OKT4C, OKT4, and OKT1. OKT4C (IgG1), and not OKT4 (IgG2) or OKT1 (IgG1) inhibited proliferation when OKT4C was added during the first 24 h of cell culture. The inhibition of OKT3 activation by OKT4C did not require Ia+ accessory cells, since T4+ cells could be activated by OKT3 in the presence of Ia- U937 cells, and this activation was markedly inhibited by OKT4C. Furthermore, T4+ cells could be induced to proliferate by OKT3 covalently linked to Sepharose beads, in the absence of any accessory cells. Under these conditions, OKT4C, but not OKT4 or OKT1 significantly inhibited proliferation. These data demonstrate that at least one mechanism by which anti-T4 antibodies inhibit T cell activation is independent of any putative role of T4 molecules in the recognition of Ia on target cells. The data are compatible with the idea that perturbation of the T4 molecules can transmit a negative signal to T4+ cells.
Multiple class I and class II major histocompatibility complex allospecificities are generated with T cell receptor variable (V) domains created by a single Ti beta V gene family.
Authors: Acuto O , Hussey R E , Reinherz E L
Published: June 2004

10 alloreactive cytotoxic T lymphocytes using REX Ti beta variable region (V) gene segments in formation of their antigen/major histocompatibility complex (MHC) T3-Ti receptor were selected, cloned, and characterized in an effort to examine the extent of receptor diversity created by this one V gene family. Multiple and distinct class II as well as class I allospecificities were generated from the formation of different Ti beta V domains. Five allospecificities were directed at various class I epitopes whereas the other five were directed at class II MHC gene products. The following conclusions were drawn: (a) Ti beta V genes do not segregate into those that encode class I and those that encode class II allospecificities; and (b) there is no restriction on the Ti beta V gene pool available to T4+ vs. T8+ T lymphocytes.
Specific suppression of allograft rejection by trinitrophenyl (TNP)-induced suppressor cells in recipients treated with TNP-haptenated donor alloantigens.
Authors: Hutchinson I V , Barber W H , Morris P J
Published: June 2004

Suppressor T cells, activated by injection of trinitrobenzene sulphonic acid in DA rats, prevented rejection of LEW kidney allografts in a donor-specific manner when adoptively transferred into syngeneic recipients along with trinitrophenyl (TNP)-haptenated LEW alloantigen. TNP-haptenated third-party alloantigen was ineffective in this system. The donor-specific suppression was dependent, too, on the haptenic portion of the chemically modified alloantigen. Hence, fluorescein isothiocyanate-donor antigen did not lead to suppression in the presence of TNP-reactive suppressor cells. There is, however, some crossreaction between DNP- and TNP-haptenated alloantigens so that TNP-reactive cells and DNP-donor antigen suppressed rejection whereas DNP-reactive cells and TNP-donor antigen did not prevent graft rejection. The suppressor cells were sensitive to cyclophosphamide and radiation but were resistant to hydrocortisone. They appear to be T cells of the OX8 (suppressor/cytotoxic) phenotype since they are positive for the pan T cell antigen W3/13, are Ig negative, and do not carry the W3/25 (T helper cell) marker. However, these suppressor cells are adherent to nylon wool. They are found mainly in the spleen, are detected there within 2 d of TNBS injection, and can persist for up to 12 wk. We propose that these cells are first-order T suppressor (Ts1) cells that act in the afferent phase of the response to a renal allograft.
Transformed lymphocytes from Abelson-diseased mice express levels of a B lineage transformation-associated antigen elevated from that found on normal lymphocytes.
Authors: Tidmarsh G F , Dailey M O , Whitlock C A , Pillemer E , Weissman I L
Published: June 2004

Animals injected with Abelson murine leukemia virus (A-MuLV) rapidly develop fatal bone marrow-derived lymphosarcomas. In all such diseased animals tested, a subpopulation of bone marrow cells expressed a monoclonal antibody-defined, B lineage transformation-associated antigen (6C3 Ag) at levels increased from that detected on normal lymphocytes. Cells bearing a high level of this antigen were found to be transformed as measured by clonal growth in agar, and they expressed surface antigen markers characteristic of early pre-B cells. High-level antigen-expressing cells were found in the bone marrow, lymph nodes, and spleen, but never in the thymus of diseased animals. This distribution agrees with the published pathology of Abelson disease.
Role of human chromosome 11 in determining surface antigenic phenotype of normal and malignant cells. Somatic cell genetic analysis of eight antigens, including putative human Thy-1.
Authors: Rettig W J , Dracopoli N C , Chesa P G , Spengler B A , Beresford H R , Davies P , Biedler J L , Old L J
Published: June 2004

The expression of eight serologically and biochemically distinct human cell surface antigens defined by monoclonal antibodies was examined on a panel of rodent-human somatic cell hybrids. Cosegregation was observed for human chromosome 11, and surface expression of all eight antigens was studied. Serological analysis of hybrids containing defined segments of human chromosome 11 permitted the regional assignment of genes controlling antigens JF23 (90 kD glycoprotein), G344 (25 kD), T43 (85 kD), A124, and NP13 to chromosome 11pter-q13, and of genes controlling Q14 (130 kD), MC139 (35 kD), and K117 (25 kD) to chromosome 11q13-qter. K117, the putative human Thy-1 antigen, was expressed at high levels in chromosome 11-containing hybrids constructed with mouse neuroblastoma cells, but showed little or no expression in hybrids constructed with mouse L cells. A similar pattern of expression in hybrids was found for MC139, an antigen shared by neuroectoderm-derived cells and normal and malignant T lymphocytes. T43 is a marker of malignant tumors (but not benign tumors) derived from a number of T43- epithelia, and the regional assignment of the T43 locus on chromosome 11 raises questions about its possible involvement in the specific rearrangements of this chromosome seen in human malignancies.
Transfection of a rat cell line with the v-Ki-ras oncogene is associated with enhanced susceptibility to natural killer cell lysis.
Authors: Johnson P W , Baubock C , Roder J C
Published: June 2004

Transfection of the v-Ki-ras oncogene into rat-1 fibroblasts resulted in the establishment of cell lines that were transformed, tumorigenic, and sensitive to lysis by natural killer (NK) cells. Characterization of effectors indicated that the killing was not related to Lyt-1+ or Lyt-2+ cells (T cells) but was associated with cells bearing NK markers (asialo GM1, NK-1.2+, and NK-2.1+). Transfected targets were also killed by cloned NK lines. The transformation determinants on rat-1 transfectants cross-competed with YAC 1.2 lymphoma cells, suggesting a common target structure on these two diverse cell types. The results indicate that the NK surveillance system can recognize and kill cells newly transformed by a member of the ras oncogene family.
Evidence for a shared HLA-A intralocus determinant defined by monoclonal antibody 131.
Authors: Spear B T , Kornbluth J , Strominger J L , Wilson D B
Published: June 2004

We describe here a monoclonal antibody, 131, which appears to recognize a determinant shared by HLA-A locus-encoded gene products. Isoelectric focusing analysis demonstrates that 131 reacts with the products of at least seven different HLA-A alleles but none of the five HLA-B allelic products tested. Together with evidence provided by other studies, this finding indicates the existence of A-unique and B-unique determinants, which may have different biological functions. Monoclonal antibody probes, such as the one described here, specific for shared intralocus determinants, may be valuable for assessing these possible functional differences.
Crosslinking of surface immunoglobulin and Fc receptors on B lymphocytes inhibits stimulation of inositol phospholipid breakdown via the antigen receptors.
Authors: Bijsterbosch M K , Klaus G G
Published: June 2004

F(ab')2 fragments of rabbit anti-mouse Ig induce proliferation of murine B lymphocytes, whereas the intact antibodies are not mitogenic. F(ab')2 anti-Ig stimulates the rapid breakdown of inositol phospholipids in B cells, resulting in the prolonged release of inositol (poly)phosphates and diacylglycerol. In marked contrast, intact anti-Ig initially induces a comparable response, which is abrogated after some 30 s. Blocking either the Fc receptors on the B cells or the Fc portion of the antibodies significantly reversed the inhibitory effect. On the other hand, both forms of anti-Ig elicited comparable increases in free cytoplasmic Ca2+ levels in B cells. These results therefore indicate that crosslinkage of Fc and surface Ig receptors on B cells inhibits inositol phospholipid breakdown (but not Ca2+ flux) resulting from ligation of the antigen receptors. Since there is evidence implicating inositol phospholipid breakdown in the induction of cell growth, this effect could provide a biochemical explanation for the known capacity of antigen-antibody complexes to inhibit B cell activation.