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Biomedical subjects

C S David

Publications and source records attributed to C S David.

At least 109 records · Page 6Linked to original sources
PubMed1995

Heligmosomoides polygyrus adult worm homogenate superantigen: presentation to T cells requires MHC class I positive accessory cells.

A series of experiments were carried out to further characterize the previously discovered Heligmosomoides polygyrus, adult worm homogenate (AWH), superantigen. AWH, in contrast to staphylococcal enterotoxin B (SEB) superantigen, was totally unable to stimulate naive thymocytes, in either the presence or the absence of exogenous accessory cells (AC). Experiments using AC from B10 congenic mice failed to indicate a requirement for a specific MHC haplotype for successful presentation of the AWH superantigen and also indicated that the presence or absence of the H-2,E molecule on AC did not affect AWH stimulation of T cell hybridomas. Furthermore, AWH was found to require the presence of MHC class I-positive AC in order to stimulate T cell hybridomas, while, in contrast, the absence of MHC Class II on AC did not affect the superantigenic properties of AWH. Initial characterization of the T cell hybridomas stimulated by the AWH superantigen, indicated that all were CD4-positive and that three of them expressed TCR V beta 8.1. Hence AWH superantigen can stimulate TCR V beta 8.1/CD4-positive T cells only in the presence of MHC Class I-positive AC.

Animals↗
PubMed1995

Polymorphism of the MHC class II Eb gene determines the protection against collagen-induced arthritis.

Collagen-induced arthritis (CIA) is an animal model of auto immune polyarthritis, sharing similarities with rheumatoid arthritis (RA). Paradoxally, susceptibility to mouse CIA is controlled by the H2A loci (DQ homologous) while RA is linked to HLA.DR genes (H2E homologous). We recently showed that the E beta d molecule prevents CIA development in susceptible H2q mice. We addressed the question of whether H2Eb polymorphism will influence CIA incidence as HLA.DRB1 polymorphism does in RA. In F1 mice, only H2Ebd and H2Ebs molecules showed protection. Using recombinant B10.RDD (Ebd/b) mice, we found that CIA protection was mediated by the first domain of the E beta d molecule. Using peptides covering the third hypervariable region of the E beta chain, we found a perfect correlation between presentation of E beta peptides by the H2Aq molecule and protection on CIA. Therefore, the mechanism by which H2Eb protects against CIA seems to rely on the affinity of E beta peptides for the H2Aq molecule.

Amino Acid Sequence↗
PubMed1995

Could HLA-DRB1 be the protective locus in rheumatoid arthritis?

Extensive studies in different ethnic groups have associated the susceptibility to development of rheumatoid arthritis (RA) with the third hypervariable region of the major histocompatibility complex (MHC) HLA-DR beta 1 molecule. On the basis of recent findings in the experimental mouse model of collagen-induced arthritis, Eric Zanelli, Miguel Gonzalez-Gay and Chella David propose that the HLA-DRB1 locus is associated with protection to RA and that the actual arthritogenic peptide-presenting molecule is HLA-DQ. Thus, the development of RA would depend upon the expression of the susceptible DQ allele and the nonprotective DRB1 alleles, along with environmental factors that trigger the autoimmune process.

Alleles↗
PubMed1995

Expression of an ovalbumin-specific V beta 8.2 TCR transgene inhibits collagen arthritis in B10.Q mice.

Previous studies have illustrated the importance of T cells bearing alpha beta TCRs in the induction and development of collagen induced arthritis (CIA) in mice. However, the scope of TCR usage in CIA has yet to be clearly defined. Given the inherent diversity of the TCR repertoire, the relative flexibility of the arthritogenic TCR repertoire specific for type II collagen (CII) is not clear. Therefore, we chose to examine the influence of a highly skewed TCR repertoire on CIA. Arthritis susceptible B10.Q (H-2q) mice were mated with C57L (H-2b) animals expressing an ovalbumin-specific V beta 8.2 TCR transgene (Tg) and Tg+ offspring were further backcrossed to B10.Q. Homozygous H-2q/q, V beta 8.2 Tg+ mice displayed a high level of V beta 8.2+ T cells in peripheral blood. However, expression of some endogenous V beta TCR, such as V beta 14, was still detected. Upon immunization with bovine CII in adjuvant, V beta 8.2 Tg+ mice were highly resistant to CIA when compared with Tg- littermates. Analysis of sera demonstrated a marked reduction in antibody specific for homologous mouse CII as well as heterologous bovine CII in Tg+ animals. Interestingly, V beta 8.2 Tg+ mice still mounted good antibody responses following immunization with human thyroglobulin, indicating that the skewed TCR repertoire affected anti-CII but not antithyroglobulin responses. Thus, our findings show that constraints placed on the TCR repertoire inhibit pathogenic responses against CII and suggest that in H-2q mice the arthritogenic TCR repertoire bears only limited flexibility.

Animals↗
PubMed1995

Genetic control of immunity to Heligmosomoides polygyrus: fixed H-2 E positive but not H-2 negative cells can present antigen to a parasite-specific T cell hybridoma.

A number of T cell hybridomas were produced to adult worm homogenate (AWH) antigen of the nematode parasite Heligmosomoides polygyrus. All of the hybridomas were of the H-2d haplotype and could potentially accept antigen in the context of either the Ad or Ed, H-2 molecules. Three types of antigen presentation were observed, with some of the T cell hybridomas accepting antigen in the context of the E and some in the context of the A molecule. A third type of hybridoma responded to antigen presented by paraformaldehyde fixed APC, but only when APCs were E positive. These same hybridomas, were however, stimulated by AWH, when the antigen was presented by syngeneic but unfixed, E positive or E negative APC. Therefore these data indicate that certain H. polygyrus-specific T cell hybridomas can accept parasite antigen when presented in the context of either the H-2 A or E molecule, but the presentation of antigen by the two different MHC Class II molecules, can apparently utilize differing processing mechanisms.

Animals↗
PubMed1995

Identification of a cyanogen bromide fragment of porcine type II collagen capable of modulating collagen arthritis in B10.RIII (H-2r) mice.

Previous studies directed towards identifying epitopes on type II collagen (CII) important in collagen induced arthritis (CIA) in mice have focused primarily on responses mounted in susceptible H-2q strains. However, the nature of T and B cell responses against CII in susceptible H-2r strains remains ill-defined. In an effort to identify regions on CII important in CIA in H-2r mice, we examined the cellular and humoral response of susceptible B10.RIII (H-2r) mice against cyanogen bromide (CB)-cleaved fragments of porcine CII. Following immunization with native porcine CII, LNC from B10.RIII mice mounted proliferative responses predominantly to peptide CB10, while negligible proliferation was detected against fragment CB9, 7, CB8, CB11 or CB12. In contrast, sera from arthritic B10.RIII mice displayed a heterogeneous pattern of reactivity against porcine CII, with strong antibody binding measured against the major fragments CB11, CB8 and CB10. To determine the in vivo significance of the dominant cellular response to CB10, B10.RIII mice received an i.v. injection of soluble CB10 seven days before immunization with native porcine CII. Mice pretreated with CB10 were highly resistant to CIA compared to control animals. Interestingly, B10.RIII mice pretreated with fragment CB11, a region of CII implicated in H-2q restricted CIA, remained susceptible to arthritis induction. Collectively, our findings indicate that the CB10 region of porcine C11 bears determinants which may be important in the induction and/or regulation of CIA in the H-2r haplotype.

Adjuvants, Immunologic↗
PubMed1995

Altered development of collagen induced arthritis in T cell receptor V beta congenic B10.RIII mice.

Analysis of the mouse T cell receptor (TCR) V beta genome has revealed the existence of two distinct genotypes which bear deletions of certain V beta genes. Mice bearing the V beta a genotype lack approximately 50% of the V beta genome while V beta c mice lack 70% of the known V beta genes. Studies of the experimental model collagen induced arthritis (CIA) have indirectly suggested that the presence of truncated V beta genotypes may influence susceptibility to this autoimmune disease. In order to confirm the influence of V beta a and V beta c genotypes on CIA, we derived mice congenic for the known V beta haplotypes in the CIA susceptible B10.RIII (H-2r) background. Flow cytometric analysis of splenic lymphocytes revealed normal T cell levels in both B10.RIII-V beta congenic lines. Expectedly, a generalized increase in the expression of some non-deleted V beta genes was detected. In addition, the mice were immunized with porcine type II collagen and monitored for CIA. B10.RIII-V beta a mice showed little difference in arthritis incidence or severity versus B10.RIII, but a significant delay in the onset of CIA was seen. In contrast, B10.RIII-V beta c mice showed a marked decrease in arthritis incidence versus B10.RIII and the severity of CIA in arthritic mice was also significantly lower (p < 0.01). Thus, in the B10.RIII strain, the presence of truncated TCR V beta genotypes alters the development of CIA. These findings may shed light on the influence of TCR genotypes in the induction and development of human rheumatoid arthritis.

Animals↗
PubMed1995

H-2 Dd transgene suppresses Theiler's virus-induced demyelination in susceptible strains of mice.

Theiler's murine encephalomyelitis virus is a picornavirus which induces chronic immune-mediated central nervous system demyelination and virus persistence in susceptible strains of mice. Using murine strains with congeneic recombinant haplotypes, the H-2D region within the class I major histocompatibility complex has been shown to be important in determining susceptibility/resistance to chronic Theiler's murine encephalomyelitis virus infection. We examined the role of H-2D in demyelinating disease with the use of transgenic D8 mice (H-2Dd, resistant haplotype) crossed to susceptible B10.Q (H-2q) and B10.S (H-2s) mice. Expression of the H-2Dd transgene dramatically suppressed demyelination and reduced the number of virus-antigen positive cells in the spinal cord 45 days following infection. More complete protection was observed in transgenic B10.Q (D8+) mice than in transgenic B10.S (D8+) mice. These experiments support the hypothesis that the immunologic basis of resistance by H-2D is determined by effective antigen presentation which prevents virus persistence and subsequent demyelination.

Animals↗
PubMed1994

Adult worm homogenate of the nematode parasite Heligmosomoides polygyrus induces proliferation of naive T lymphocytes without MHC restriction.

The documented in vitro response of mouse T cells to parasite antigens is typically anamnestic and H-2 restricted. As yet, there have been no confirmed reports of the existence of a non-H-2-restricted, superantigen type of response to the antigens of metazoan parasites. Reported here are data which show that antigens produced by the adult stage of the nematode parasite Heligmosomoides polygyrus (= Nematospiroides dubius) can stimulate naive T cells in vitro to proliferate and produce IL-2. A series of T cell hybridomas has been used to show that adult worm homogenate of H. polygyrus can stimulate parasite antigen naive T cells. This response is independent of the H-2 haplotype of the antigen-presenting accessory cells and does not appear to be influenced by the presence or absence of an H-2 E molecule. However, successful presentation of the H. polygyrus superantigen does require the presence of metabolically active accessory cells and fixation of the accessory cells with paraformaldehyde abrogates the response of the target cells. This discovery has important implications for the study of the role of superantigens in host/parasite interactions and will also help to expand current knowledge about the relationship between chronic intestinal nematodes and the host immune system.

Animals↗
PubMed1994

Protective role of major histocompatibility complex class II Ebd transgene on collagen-induced arthritis.

Collagen-induced arthritis (CIA) is an animal model of autoimmune inflammatory polyarthritis that has features similar to rheumatoid arthritis (RA). Much like RA, susceptibility to mouse CIA is influenced by the major histocompatibility complex (MHC), H-2, and restricted to the H-2q and H-2r haplotypes. Whereas the role of the H-2A molecule in susceptibility to CIA is well established, little is known about the role of H-2E molecule in the disease. In this study, we analyzed the effect of a transgenic E beta d molecule on CIA susceptibility in a recombinant mouse B10.RQB3, which expresses the CIA susceptible Aq genes and an Eak gene, but does not produce an E molecule since Ebq is nonfunctional. In the presence of an Ebd transgene, a viable E molecule is generated. Whereas B10.RQB3 were susceptible to CIA, B10.RQB3-E beta d+ showed a dramatic reduction in the incidence of arthritis as well as a decrease in the level of anti-mouse and anti-bovine CII antibodies in their serum. No clear cut differences in the expression of T cell receptor (TCR) V beta was observed between E beta d+ and E beta d- transgenic mice. Mechanisms underlying the protective effect of E beta d transgenic molecule on CIA may shed light on how HLA-DR molecules influence human RA.

Animals↗
PubMed1994

Collagen-induced arthritis and TCRs in SWR and B10.Q mice expressing an Ek alpha transgene.

B10.Ek alpha transgenic mice were mated with H2-E B10.Q and SWR mice. F1 and F1 x parental strain backcross progeny were tested for arthritis and autoimmune reactivity to mouse type II collagen (MII) after immunization with bovine, chick, deer, or human type II collagen. The results were correlated with the H-2 haplotype (b/q vs q/q) and the TCR V beta profile of peripheral blood T cells in each mouse. Hybrid progeny expressed TCR profiles different from either parent because of the TCR V beta genomic deletions of SWR mice (V beta a), the wild-type TCR allele of C57Bl/10 (B10) mice (V beta b), and the intrathymic negative selection processes resulting from cell surface expression of Ek alpha-A q beta or Eb beta-Ek alpha, together with the integrated retroviral genes Mtv-9 originating in B10 mice and Mtv-7 (Mls-1a) from SWR mice. (B10.Ek alpha x SWR)F1 mice developed higher IgG anti-MII Ab titers, but much milder arthritis than (B10.E x B10.Q)F1 mice. Expression of Ek alpha did not change the level of IgG anti-MII Ab nor the degree of susceptibility to collagen-induced arthritis (CIA) in the H-2q/q and H-2b/q progeny of (B10.Ek alpha x B10.Q)F1 x B10.Q matings, indicating that the Mtv-9-reactive, TCR V beta 5+, and V beta 11+ T cells are not critical to CIA. Among bovine type II collagen-immunized (B10.Ek alpha x SWR)F1 x SWR backcross mice: 1) arthritis severity is associated with the presence of V beta b (p < or = 0.01) and expression of Ek alpha (p < or = 0.05), but not with the MHC haplotype (b/q vs q/q); 2) regression analysis showed a significant association (R = 0.99) between IgG anti-MII Ab titers and the level of Mtv-7-reactive V beta 6+ T cells that was detectable in the IgG1, but not the IgG2a subclass. The data prompt the speculation that Mtv-7-reactive V beta 6+ (or V beta 7+) T cells in (B10.EK alpha x SWR)F1 x SWR mice express Th2-type properties, and thus contribute to the combination of mild arthritis but high anti-MII Ab titers that characterize mice of SWR heritage.

Animals↗
PubMed1994

Collagen-induced arthritis in T cell receptor V beta congenic B10.Q mice.

B10.Q (H-2q) mice congenic for the truncated T cell receptor (TCR) V beta a and V beta c haplotypes were derived to examine the influence of TCR V beta genomic deletions in murine collagen-induced arthritis (CIA). Previous studies using gene complementation and segregation analyses suggested that in SWR (H-2q) mice, possession of the V beta a gene deletion results in CIA resistance. However, other studies have suggested alternative hypotheses. Thus, analysis of TCR V beta congenic mice allows for direct examination of V beta genotypes in CIA control. After immunization with bovine type II collagen, B10.Q-V beta a mice showed no difference in arthritis susceptibility, onset, or severity when compared with prototype B10.Q mice. In contrast, B10.Q-V beta c mice, which lack the V beta 6, 15, 17, and 19 families in addition to the V beta a deletion, were highly resistant to CIA. In vivo depletion of V beta 6+ T cells in B10.Q-V beta a mice significantly delayed arthritis onset suggesting that, among those V beta genes present in V beta a but absent in V beta c, V beta 6+ T cells contribute to arthritogenesis. Our findings show that, in B10.Q-V beta congenic mice, while the V beta a genotype does not prevent CIA, the highly truncated V beta c genotype renders B10.Q mice resistant to CIA. Thus, deletions within the V beta TCR genome can indeed influence CIA and suggests that the TCR repertoire displays only marginal flexibility in response to arthritogenic stimuli.

Animals↗
PubMed1994

Effects of human class I transgenes on Toxoplasma gondii cyst formation.

MHC class I genes are important in the regulation of cyst number in mice perorally infected with Toxoplasma gondii. Since human MHC class I molecules may be capable of functioning as restriction elements in mice, to determine whether class I genes also control outcome of T. gondii infection for humans, a transgenic mouse model was developed using human class I genes in mice. Human HLA-B27 and Cw3 transgenic mice, with the cyst-susceptible B10 mouse background, were tested for resistance to cyst formation after peroral infection with the Me49 strain of T. gondii. Introduction of the B27 gene into susceptible mice made them even more susceptible to T. gondii brain cyst formation. In contrast, HLA-DB27 transgenic mice that have a substitution of the alpha 3 portion of the human class I molecule with the alpha 3 portion of the mouse Kd molecule had the same number of brain cysts as susceptible B10 control mice when perorally infected. Similarly, HLA-Cw3 transgenic mice had the same number of brain cysts as the susceptible B10 controls. These results indicate that the interaction between CD8 on mouse T cells and the human class I molecule in transgenic mice does not always occur, and sometimes may hinder a normal response. Furthermore, B27 and Cw3 transgenes did not generate resistance to cyst formation in infection by T. gondii.

Animals↗
PubMed1994

Noninvolvement of V beta 8+ T cells in murine thyroglobulin-induced experimental autoimmune thyroiditis.

In experimental autoimmune thyroiditis (EAT) induced with mouse thyroglobulin (MTg), T cell receptor (TCR) V beta gene usage in the pathogenesis of disease is unknown. We report here studies evaluating V beta 8 gene usage in EAT, as V beta 8+ T cells are reportedly involved in some experimental autoimmune diseases. Spleen cells (SC) from MTg-immunized CBA/J (H-2k) mice were activated in vitro for adoptive transfer into syngeneic recipients. Elimination of V beta 8+ T cells by treating recipients with V beta 8 monoclonal antibody (mAb) following transfer of MTg-activated SC did not reduce disease severity. Conversely. MTg-primed SC were stimulated in vitro with V beta 8 mAb or staphylococcal enterotoxin B, which activates V beta 8+ T cells in CBA/J mice. Neither activated population transferred disease, in contrast to cells activated with MTg. Thus, in MTg-induced EAT, V beta 8+ T cells do not play a major role in pathogenesis.

Animals↗