Islet cell autoimmunity in NOD mice transgenic for HLA-DQ8 and lacking I-Ag7.
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Animals↗
Biomedical subjects
C S David
Publications and source records attributed to C S David.
Animal models of human leukocyte antigen B27-linked arthritides.
The major histocompatibility complex class I allele human leukocyte antigen (HLA) B27 is strongly associated with human spondyloarthropathies. To date, 12 subtypes of HLA-B27 are known and most of them are linked with human spondyloarthropathies in different ethnic populations. Although these subtypes differ from each other by a few amino acids, the have an identical B pocket in the base of the antigen-binding groove. Considering the structure of HLA-B27 subtypes and their peptide binding specificity, it is important to consider their role as antigen-presenting molecules. Many B27-linked diseases begin after an infection with an enterobacteria, suggesting a role for environmental antigens in addition to an HLA-B27 molecule. To delineate the role of infection, studies have been carried out in animal models of reactive arthritidis. More recently, transgenic animal models have been used to understand the handling of environmental antigens by HLA-B27 molecule. This article discusses some of these transgenic and nontransgenic animal models of human diseases.
Animals↗
Modulation of HLA-DQ-restricted collagen-induced arthritis by HLA-DRB1 polymorphism.
Mouse class II-deficient HLA-DQB1*0302, DQA1*0301 (DQ8) transgenic mice are susceptible to severe collagen-induced arthritis (CIA), an animal model for rheumatoid arthritis. To examine whether polymorphism at the DRB1 locus can modulate DQ-restricted arthritis, we generated double-transgenic (DR/DQ) mice. HLA-DRB1*1502 (DR2) and DRB1*0301 (DR3) were introduced separately into CIA susceptible DQ8.Abeta transgenic mice to generate DQ8/DR2.Abeta and DQ8/ DR3.AbetaO mice. The HLA-DR molecules in these mice were found to be functional on the basis of their positive/negative selection of the Vbeta T cell repertoire. Introduction of the DR2 gene led to a significant decrease in disease incidence in DQ8.Abeta mice, while the DR3 transgene had no effect. In vitro T cell proliferative responses against bovine Cll collagen in primed mice were higher in DQ8/DR3 mice compared with DQ8/DR2 mice. Cytokine analysis showed a Th2 profile in DQ8/DR2 mice, while DQ8/DR3 mice showed a Th1 profile. These results suggest that DRB1 polymorphism can modulate the disease.
Animals↗
HLA-B27 and other predisposing factors in spondyloarthropathies.
Studies from around the world have confirmed the association between HLA-B27 and human spondyloarthropathies. The onset of many HLA-B27-linked arthritides follows an infection with enterobacteria. How bacteria interact with HLA-B27 and modify the immune system to give rise to the clinical disease is currently unclear. The roles of other genetic factors, including major histocompatibility complex class II genes and other genes located within this region (Tap/Lmp), have been postulated in certain spondyloarthropathies. We are using transgenic and knockout mice to answer some of these unsolved issues. This review discusses recent findings from our laboratories.
ATP-Binding Cassette Transporters↗
Differential effects of infection with a Babesia-like piroplasm, WA1, in inbred mice.
A newly identified intraerythrocytic Babesia-like organism, WA1, and its relatives were recently shown to be infectious for humans in the western United States. The purpose of the present study was to determine the susceptibilities of selected mouse genotypes to WA1 infection in an attempt to develop a murine model of the human disease. Several mouse strains were inoculated intraperitoneally with various passages of WA1-parasitized erythrocytes. Parasitemia was evaluated by blood smears and by PCR with blood samples collected at various intervals after inoculation. Hematologic parameters were monitored in blood samples at all intervals. C57BL/6 and C57BL/10 mice exhibited mortality rates of <10%. BALB/cJ, CBAJ, and 129/J mice had higher peak parasitemias than did C57BL mice, with mortality rates of 40, 50, and 50%, respectively. A/J, AKR/N, C3H, and DBA/1J mice also had higher peak parasitemia and mortality rates (>95%). An F1 cross of C57BL/6 (resistant) and C3H.RKK (susceptible) mice had a mortality rate similar to that of the resistant parental strain. Histopathology of BALB/cJ and C3H mice at 9 and 14 days after inoculation revealed erythrophagocytosis and deposition of an iron-negative pigment in multiple organs. Morbidly ill C3H mice at 14 days had severe pulmonary edema, hemoglobinuria, and glomerulonephritis.
Animals↗
Flexibility of the thyroiditogenic T cell repertoire for murine autoimmune thyroiditis in CD8-deficient (beta2m -/-) and T cell receptor Vbeta(c) congenic mice.
In murine experimental autoimmune thyroiditis (EAT), previous studies have revealed a highly adaptable thyroiditogenic T cell repertoire which involves both CD4+ and CD8+ T cells in the susceptible H2k strain. To further test this flexibility, congenic B10.K mice lacking CD8+ T cells (B2m -/-) or harboring 70% T cell receptor (TCR) Vbeta gene deletions (Vbeta(c)) were immunized with mouse thyroglobulin (MTg) and evaluated for EAT 28 days later. All B2m -/- mice developed moderate antibodies to MTg, and thyroidal inflammation was comparable to B10.K mice, averaging 35-40%. Spleen cells (SC) from MTg-immunized mice were then injected into syngeneic recipients after stimulation in vitro with MTg or with conserved, thyroxine (T4)- or thyronine (T0)- containing 12mer peptides, hT4(5), hT0(2553), or hT4(2553), derived from the primary hormonogenic sites at position 5 or 2553 of human Tg. As previously shown in another H2k strain (CBA/J), all three peptides activated MTg-primed SC to transfer EAT in B10.K mice. hT4(5) and hT4(2553) were further tested in B10.K-Vbeta(c) and beta2m- B10.K mice. Both peptides expanded thyroiditogenic T cells in either strain, resulting in severe thyroiditis in syngeneic recipients. That EAT can develop in the absence of CD8+ T cells or in the presence of a severely restricted TCR repertoire underscores the remarkable flexibility of the thyroiditogenic T cell profile in the susceptible k haplotype.
Adoptive Transfer↗
HLA-DQB1 polymorphism determines incidence, onset, and severity of collagen-induced arthritis in transgenic mice. Implications in human rheumatoid arthritis.
Certain HLA-DR alleles have been associated with predisposition to human rheumatoid arthritis (RA). There is also evidence that certain HLA-DQ alleles may also be important in determining susceptibility to RA. We have previously demonstrated that mice transgenic for HLA-DQ8, a DQ allele associated with susceptibility to RA, develop severe arthritis after type II collagen immunization. To investigate the influence of polymorphic difference at the DQ loci on susceptibility to arthritis, we generated mice transgenic for HLA-DQ6, an allele associated with a nonsusceptible haplotype. The DQ6 mice were found to be resistant to collagen-induced arthritis. We also assessed the combined effect of an RA-susceptible and an RA nonassociated DQ allele by producing double-transgenic mice expressing DQ6 and DQ8 molecules, representing the more prevalent condition found in humans where heterozygosity at the DQ allele is common. The double-transgenic mice developed moderate CIA when immunized with CII when compared with the severe arthritis observed in DQ8 transgenic mice, much like RA patients bearing both susceptible and nonsusceptible HLA haplotypes. These studies support a role for HLA-DQ polymorphism in human RA.
Age Factors↗
Experimental autoimmune myasthenia gravis in B10.BV8S2 transgenic mice: preferential usage of TCRAV1 gene by lymphocytes responding to acetylcholine receptor.
Multiple TCRBV genes have been implicated in experimental autoimmune myasthenia gravis (EAMG) pathogenesis in susceptible H-2(b) strains of mice. We studied the contribution of specific TCRBV and AV genes in EAMG pathogenesis using B10.BV8S2 transgenic mice (H-2[b]). The TCR transgenic mice predominantly have TCRBV8S2 transgene, but can use any of the endogenous AV gene repertoire. The transgenic mice were immunized with acetylcholine receptor (AChR) in CFA and evaluated for EAMG pathogenesis. Although the lymphocyte responses to AChR in B10.BV8S2 transgenic and nontransgenic TCR wild-type mice were equivalent, a marked reduction in lymphocyte response to the dominant AChR alpha chain peptide 146-162 was observed in the TCR transgenic mice. After boosting with AChR in CFA, anti-AChR Abs were detected in the serum, and 14 of 42 (33%) of the TCR transgenic mice developed clinical EAMG. Furthermore, EAMG in TCR transgenic mice was prevented by treatment with mAb to TCRBV8, which depleted BV8-expressing T cells. Cloning and sequencing of TCRAV genes from AChR-reactive T cells from B10.BV8S2 transgenic mice revealed a pattern of restricted TCRAV gene usage. The majority (60%) of the clones sequenced showed a sequence identical with that of the TCRAV1S8 gene. In the normal spleen cells of TCR transgenic mice, AV gene usage was more random. Thus, despite the presence of a complete endogenous TCRAV repertoire in B10.BV8S2 transgenic mice, T cells responding to AChR preferentially used a single endogenous TCRAV gene, thus implicating the involvement of the TCRAV1S8 gene in EAMG pathogenesis.
Animals↗
Critical residues on HLA-DRB1*0402 HV3 peptide for HLA-DQ8-restricted immunogenicity: implications for rheumatoid arthritis predisposition.
Recently, we have proposed that the combination of HLA-DQ and -DR alleles is responsible for the association of the HLA class II region with rheumatoid arthritis (RA). According to this model, some HLA-DQ alleles, namely DQ4, DQ7, DQ8, and DQ9, predispose carriers to severe RA, but a self peptide of sequence KDILEDERAAVDTYC from the third hypervariable (HV3) region of some DRB1 alleles, including DRB1*0402, can protect from the disease if presented by DQ molecules. This model implies that DQ4, DQ7, DQ8, and DQ9 should be able to present a set of common peptides, despite polymorphisms in their Ag binding groove. In the present study, we have further analyzed the immunogenicity of the DRB1*0402 HV3 peptide in DQ8-transgenic mice. We found that the motif DERAA guarantees DQ8-restricted immunogenicity, and that R is the main anchor residue for binding of the DRB1*0402 peptide to DQ. Interestingly, the p1 pocket that probably controls binding of the R residue is identical in all four RA-associated DQ molecules. Our results imply that the association of RA with some DR subtypes can be explained by their linkage with DQ alleles displaying a binding site for similar "arthritogenic" peptides.
Amino Acid Sequence↗
Primary hormonogenic sites as conserved autoepitopes on thyroglobulin in murine autoimmune thyroiditis: role of MHC class II.
A few synthetic peptides corresponding to amino acid sequences on human thyroglobulin (Tg) have been reported to induce moderate thyroiditis or activate mouse Tg (MTg)-primed T cells to transfer thyroiditis in mice susceptible to experimental autoimmune thyroiditis. Using three pairs of 12-mer peptides (1-12, 2549-2560, 2559-2570), with thyroxine (T4) or noniodinated thyronine (T0) at the conserved, hormonogenic site 5, 2553, or 2567 respectively, we reported that iodination was not required for a Tg hormonogenic site to be a thyroiditogenic autoepitope. To determine the relative importance of MHC class II and T cell receptor (TCR) repertoire, we compared two EAT-susceptible k and s (CBA and A.SW) haplotypes and their respective MHC-identical strain (C57BR and SJL) with approximately 50% genomic deletion of TCR Vbeta genes. Whereas k and s strains develop MTg-induced EAT, vigorous immunization with peptides containing T4 or T0 at either 5 or 2553, but not at 2567, led to mild (10-20%) thyroiditis only in some mice of either k strain. TCR Vbeta gene differences played a minor role. T cell responses to all peptide pairs were quite similar in CBA and C57BR mice, and both hT0(2553) and hT4(2553) reciprocally primed and stimulated their T cells. In adoptive transfer, SJL mice were somewhat more responsive to peptide activation than A.SW but much weaker than k strains. By comparing T4- and T0-containing peptides in different haplotypes, we show further that antigenicity of conserved hormonogenic sites is intrinsic, dependent more on amino acid sequence and binding to appropriate class II molecules and less on TCR repertoire or iodination of T0.
Adoptive Transfer↗
The mystery of HLA-B27 and disease.
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Animals↗
Role of mouse and human class II transgenes in susceptibility to and protection against mouse autoimmune thyroiditis.
Mouse experimental autoimmune thyroiditis (EAT), a model for Hashimoto's thyroiditis, is induced by immunizing with mouse thyroglobulin (MTg). To study the extent of H2A involvement in EAT, we introduced AaAb genes from susceptible k mice into resistant or intermediately susceptible strains which do not express H2E molecules. Thyroiditis was severe in resistant B10.M (H2(f)) mice carrying the double transgene AakAbk. Likewise, thyroid infiltration was significantly extended in intermediate B10.Q (H2(q)) mice with the same transgene. To examine the effect of H2E molecules in the presence of H2A-mediated susceptibility, we introduced an Eak transgene into E- B10.S mice to express the Ebetas molecule and observed significant reduction in EAT severity in B10.S(E+) mice. On the other hand, the presence of an Ebd transgene in B10.RQB3 (H2Aq) mice resulting in the expression of H2Ebetad molecules did not alter EAT susceptibility, suggesting a role for Eb gene polymorphism in protection against EAT. We have shown recently that the HLA-DRB1(*)0301 (DR3) transgene conferred EAT susceptibility to B10. M as well as class II-negative B10.Ab0 mice. However, we report here that the HLA-DQB1(*)0601 (DQ6b) transgene in B10.M or HLA-DQA1(*)0301/DQB1(*)0302 (DQ8) transgene in class II-negative Ab0 mice did not. These studies show the differential effects of class II molecules on EAT induction. Susceptibility can be determined when class II molecules from a single locus, H2A or HLA-DQ, are examined in transgenic mice, but the overall effect may depend upon the presence of both class II molecules H2A and H2E in mice and HLA-DQ and HLA-DR in humans.
Animals↗
T cell recognition of human pre-proinsulin peptides depends on the polymorphism at HLA DQ locus: a study using HLA DQ8 and DQ6 transgenic mice.
HLA DQ8 (DQ A1*0301/DQB1*0302) molecule is implicated in the susceptibility to insulin dependent diabetes mellitus whereas, HLA DQ6 (DQ A1*0103/DQB1*0601) molecule may have a protective effect. In this study we used mice transgenic to HLA DQ8 and HLA-DQ6 to elucidate the T cell determinants on a putative islet cell target antigen, insulin. These mice do not express endogenous mouse class II heterodimers on cell surface. Using overlapping synthetic peptides spanning the complete sequence of huma pre-proinsulin, we identified the sequences recognized by T cells in DQ8 transgenic mice and compared these to those in DQ6 transgenic mice. We observed a differential pattern of recognition of epitopes on human pre-proinsulin (HPI) polypeptide presented by the HLA DQ8 allele as compared to HLA DQ6. The sequences 1-24 and 44-63 were immunodominant in DQ8 transgenic mice while DQ6 transgenic mice primarily recognized sequences 14-33 and 74-93 of HPI. We found that the immune response generated in HLA DQ8 transgenic mice against HPI 1-24 cross-reacted to the mouse pre-proinsulin sequence 1-24. The T cell response were specifically inhibited using anti-CD4 and anti-DQ8 monoclonal antibodies. This cross-recognition of self sequences raises the possibility of modulation of experimental diabetes using this peptide.
Amino Acid Sequence↗
Non-specific binding of IgG1 to Heligmosomoides polygyrus: adult worm homogenate superantigen is a target for immunoglobulin-induced inhibition.
Previous evidence had indicated that selected antigens contained in H. polygyrus adult worm homogenate (AWH) could bind non-specifically to mouse IgG1. To determine whether H. polygyrus superantigen was one of these binding molecules, an inhibition assay was carried out using monoclonal antibodies (MoAb) to block the in vitro superantigen response. The results indicated that non-specific IgG1 binding could inhibit the cellular response to the superantigen. This assumption was tested using affinity chromatography to extract those antigens which bound non-specifically to mouse IgG1. Both the protein fraction which bound to the column and the unfractionated AWH demonstrated superantigen activity, as described previously. In contrast, the unbound fraction contained no superantigen activity. None of the tested fractions exhibited non-specific mitogen activity. These results indicate that the superantigen produced by H. polygyrus binds to host IgG1 of any specificity and this binding can inhibit further host recognition of this molecule. Additionally, it was demonstrated that an apparently similar superantigen is also contained in L4 homogenate, and is strongly represented in the excretory/secretory (E/S) proteins produced by both adult and L4 parasitic stages. Therefore, it is probable that H. polygyrus superantigen influences the host during both the L4 and adult stages of the life-cycle.
Animals↗
Expression of the H2-E molecule mediates protection to collagen-induced arthritis in HLA-DQ8 transgenic mice: role of cytokines.
Transgenic mice expressing DQA1*0301 and DQB1*0302 (HLA-DQ8) molecules in class II-deficient Ab degree mice are susceptible to collagen-induced arthritis (CIA). To evaluate the role of the H2-E molecule (a homolog of HLA-DR) in DQ-restricted arthritis, the H2-E gene was introduced into DQ8.Ab degree mice to generate DQ8/E+.Ab degree mice. Expression of the E molecule protects DQ8.Ab degree mice against arthritis. In vitro studies using draining lymph nodes from mice primed with bovine type II collagen (BII) showed that the response to BII in both transgenics is DQ and CD4 restricted. Challenge with BII in vitro leads to production of high levels of IFN-gamma in DQ8 and IL-4 in DQ8/E+ mice. We have hypothesized that the H2-E molecule modulates the T cell repertoire and changes the cytokine balance, resulting in protection of disease.
Animals↗
Immunogenicity and contraceptive potential of a human zona pellucida 3 peptide vaccine.
Immunization with zona pellucida 3 (ZP3) glycoprotein induces infertility in primates and is a target antigen for a contraceptive vaccine. However, loss of ovarian function is a long-term side effect. A possible mechanism is autoimmune ovarian disease induced by ZP3-specific autoreactive T cells, demonstrated in mice immunized with a murine ZP3 peptide in complete Freund's adjuvant. Indeed, a murine contraceptive vaccine that elicits antibodies to zona pellucida (ZP) without concomitant pathogenic T-cell activation has been achieved by a chimeric peptide (CP) consisting of a native ZP3 B-cell epitope and a foreign helper T-cell peptide. Herein, we evaluate the CP strategy in primate for human ZP3 (hZP3) vaccine development. A CP was constructed that consisted of a known helper T-cell epitope from the malarial circumsporozoite protein and a native B-cell epitope of hZP3. The human CP elicited antibodies to ZP3 in macaques without a measurable T-cell response to the hZP3 peptide. The serum antibodies reacted with macaque and human ZP and significantly inhibited human sperm binding to oocytes in vitro. Moreover, the CP elicited antibodies to human ZP in mice that lack murine major histocompatibility complex (MHC) class II molecules but express transgenic human HLA-DR3, -DQ6, or DQ8 molecules. Therefore, this study 1) provides evidence to support the feasibility of the CP strategy in hZP3 vaccine development and 2) describes a novel approach for evaluating the influence of polymorphic human MHC on vaccine immunogenicity without human immunization.
Animals↗
Structure-activity studies of hydrophobic amino acid replacements at positions 9, 11 and 16 of glucagon.
We have designed and synthesized eight compounds 2-9 which incorporate neutral, hydrophobic amino acid residues in positions 9, 11 and 16 of the glucagon molecule: (2) [desHis1, Val9. Ile11,16] glucagon amide, (3) [desHis1, Val9,11,16] glucagon amide, (4) [desHis1, Val9, Leu11,16]glucagon amide, (5) [desHis1, Nle9, Ile11,16]glucagon amide, (6) [desHis1, Nle9, Val11,16] glucagon amide, (7) [desHis1,-Nle9, Leu11,16] glucagon amide, (8) [desHis1, Val9, Leu11,16, Lys17,18, Glu21] glucagon amide and (9) [desHis1, Nle9, Leu11,16, Lys17,18, Glu21] glucagon amide. The effect of neutral, hydrophobic residues at positions 9, 11 and 16 led to good binding to the glucagon receptor. Compared to glucagon (IC50 = 1.5 nM), analogues 2-9 were found to have IC50 values of 6.0, 6.0, 11.0, 9.0, 2.5, 2.8, 6.5 and 7.0 nM, respectively. When these compounds were tested for their ability to block adenylate cyclase (AC) activity, they were found to be antagonists having no stimulation of adenyl cyclase, with pA2 values of 6.15, 6.20, 6.30, 7.25, 6.10, 7.30, 6.25 and 7.25, respectively.
Adenylyl Cyclase Inhibitors↗
Allelic polymorphisms at the H-2A and HLA-DQ loci influence the response of murine lymphocytes to the Mycoplasma arthritidis superantigen MAM.
Mycoplasma arthritidis, an agent of rodent arthritis, produces a potent superantigen (SAg), MAM. Previous work established that MAM is presented to T cells by murine H-2E or the homologous human HLA-DR molecules and that lymphocytes lacking a functional H-2E molecule fail to respond to MAM. Recently, more potent and purified preparations of MAM of known protein content have become available. This enabled us to more effectively compare the response of MAM with that of other SAgs by using lymphocytes from mice whose cells express different H-2A and HLA-DQ molecules. Here we demonstrate that cells from some H-2E-negative mouse strains respond to higher concentrations of MAM. By use of inbred, congenic, and recombinant mice, we show that these differences are, in fact, exercised at the level of the major histocompatibility complex (MHC) and that allelic polymorphisms at H-2A influence reactivity to MAM. In addition, polymorphisms at HLA-DQ, the human homolog of H-2A, also influence responsiveness to MAM. Cells expressing DQw6 (HLA-DQA1*0103 and DQBI*0601 chains) gave much higher responses to MAM than did cells expressing DQw8 (DQA1*0301 and DQB1*0302 chains). In fact, responses of lymphocytes expressing DQB1*0601 chains homozygously were as high as those observed for cells expressing a functional H-2E molecule. Murine lymphocytes responded less well to staphylococcal enterotoxin B (SEB) and SEA, but mouse cells expressing human MHC molecules gave much higher responses. The patterns of reactivity observed with cells expressing the various murine and human alleles differed for MAM, SEB, and SEA, suggesting that each of these SAgs interacts with different regions or residues on MHC molecules. It has been hypothesized that SAgs might play a role in susceptibility to autoimmune disease. Allelic polymorphisms at MHC loci might therefore influence susceptibility to autoimmune disease by affecting immunoreactivity to specific superantigens.
Alleles↗