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ABSTRACT: To identify pathogenic epitopes on human thyroglobulin (hTg), a homodimer of 660kDa, we have applied a computer-based algorithm to predict potential HLA-DR3-binding peptides and have tested them in DR3-transgenic mice. Of the 39 peptides selected, four stimulated a proliferative response from hTg-primed cells of DR3+ mice, but not DQ8+ mice. Of the four peptides, one, hTg2079, was consistently pathogenic. Thyroiditis was not only produced by adoptive transfer of hTg-primed, hTg2079-activated cells but also by direct immunization with the peptide. These results demonstrate the utility of using this computer-based algorithm with synthetic peptides to help identify pathogenic T cell epitopes on hTg.
Cellular Immunology 07/2004; 229(2):79-85. · 1.97 Impact Factor
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ABSTRACT: Experimental autoimmune thyroiditis (EAT) can be induced in genetically susceptible mice by immunization with the self antigen, thyroglobulin (Tg). Since susceptibility is linked to H2 class II molecules, we have generated human leukocyte antigen (HLA) class II transgenic mice to study potential HLA associations with Hashimoto's thyroiditis. DR3 (HLA-DRA/DRB1*0301) and DQ8 (HLA-DQA1*0301/DQB1*0302) transgenes were introduced into class II-negative Ab(0)/B10 and Ab(0) nonobese diabetic (Ab(0)/NOD) mice. Previous work had shown that DR3 transgenic mice were susceptible to both mouse Tg and human Tg-induced EAT, whereas DQ8 transgenic mice were moderately susceptible only to human Tg induction. In this report, we examined the effect of DQ8 transgene on mouse Tg- and human Tg-induced EAT in double transgenic DR3/DQ8 mice. After mouse Tg induction, thyroiditis in DR3(+)DQ8(+) Ab(0)/B10 mice was significantly less severe than in DR3(+) mice but more severe than in DQ8(+) mice. No difference in thyroiditis was observed between DR3(+) and DR3(+)DQ8(+) mice in another background strain, Ab(0)/NOD. However, after immunization with human Tg, DQ8 coexpression downregulated thyroiditis severity, compared to DR3(+) mice, whereas thyroiditis was more extensive than in DQ8(+) mice. Thus, depending on the background strain and the Tg used to induce disease, the presence of the DQ8 transgene can reduce thyroiditis mediated by DR3 molecules.
Journal of Autoimmunity 06/2002; 18(3):213-20. · 7.37 Impact Factor
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ABSTRACT: In contrast to H2-based susceptibility to experimental autoimmune thyroiditis (EAT) induced with thyroglobulin (Tg), human leukocyte antigen (HLA) association with Hashimoto's thyroiditis, the human counterpart, is less clear, and determining association is further complicated by DR/DQ linkage disequilibrium. Previously, we addressed the controversial implication of HLA-DR genes by introducing HLA-DRA/DRB1*0301 (DR3) transgene into endogenous class II negative H2Ab(0) mice. EAT induction with either human (h) or mouse (m) Tg demonstrated the permissiveness of DR3 molecules for shared Tg epitopes. Here, we examined the participation of HLA-DQ genes by introducing DQA1*0301/DQB1*0302 (DQ8) transgene into class II negative Ab(0) or class I and II negative beta(2)m((-/-)) Ab(0) mice. About 50% and 80% of HLA-DQ8(+) Ab(0) and beta(2)m(-) Ab(0) mice, respectively, developed moderate EAT after hTg immunization, but only minimal response to mTg. The hTg presentation to hTg-primed cells was blocked by anti-DQ mAb in vitro. By contrast, HLA-DRB1*1502 (DR2) and *0401 (DR4) transgenes contributed little to hTg induction. Similarly, DQA1*0103/DQB1*0601 or DQA1*0103/DQB1*0602 (DQ6) transgenic Ab(0) mice were unresponsive to hTg induction and carried no detectable influence in DQ8/DQ6 double transgenic mice. Thus, both HLA-DR and -DQ polymorphism exists for hTg in autoimmune thyroiditis. The use of defined single or double transgenic mice obviates the complications seen in polygenic human studies.
Human Immunology 05/2002; 63(4):301-10. · 2.84 Impact Factor
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ABSTRACT: Using single H2 and HLA class II transgenic mice, in the absence of endogenous H2 class II molecules, we have studied the permissiveness of class II molecules for experimental autoimmune thyroiditis (EAT). Resistant strains expressing susceptible class II molecules, H2Ak or HLA-DR3, developed EAT, clearly demonstrating the importance of class II gene inheritance. Polymorphism for HLA-DRB1 was observed, as DR3, but not DR2 or DR4, molecules were permissive for EAT induction with either mouse (m) or human (h) thyroglobulin (Tg). HLA-DQ polymorphism was also detectable, as hTg-induced EAT developed in DQ8+, but not DQ6+, mice. Class II gene interactions leading to reduced EAT severity were observed in H2 transgenic mice, when H2E transgene was expressed in H2A+ mice or H2A molecules were introduced into our novel H2A- E+ transgenic model. Similarly, in DR3+ mice, only the DQ8 transgene reduced EAT severity, depending on both background genes (C57BL/10 or NOD) and Tg species. Based on computer-predicted, class II-binding motifs, potential pathogenic Tg peptides, either unique to hTg (H2A- E+ model) or shared between mTg and hTg (HLA-DR3+ model), were identified. We have also developed a Graves' disease model by immunizing DR3+ mice with TSH receptor DNA. Thus, transgenic models are excellent tools to study human autoimmune thyroid diseases in the context of murine EAT.
Autoimmunity 36(6-7):397-404. · 2.47 Impact Factor
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ABSTRACT: Murine experimental autoimmune thyroiditis (EAT) is a T-cell-mediated disease, but the T cell receptor (TCR) Vβ gene usage in pathogenesis has not been well delineated. One approach is to utilize bacterial superantigens, such as staphylococcal enterotoxin (SE) A and B, to stimulate known sets of TCR Vβ families in mouse thyroglobulin (mTg)-primed cells for thyroiditis transfer. Our previous use of SEB to activate mTg-primed cells led to no thyroiditis transfer, despite a major increase in Vβ8+ T cells. Unlike SEB, SEA activation did transfer thyroiditis. To determine which thyroiditogenic Vβ+ T cells were involved, SEA-activated T cells have now been analyzed. After repeated SEA activation in vitro, both mTg-reactive and thyroiditogenic cells persisted. FACS analysis indicated that most Vβ13+ cells were “large” cells (IL-2R+) and expressed the activation marker, transferrin receptor (CD71). RT–PCR analysis also showed the presence of both Vβ13+ and SEA-reactive Vβ1+ cells. Since our previous analyses by RT–PCR of the thyroid infiltrate after either induction or adoptive transfer have implicated both Vβ13+ and Vβ1+ cells, their activation by SEA to transfer thyroiditis further supports their role.
Cellular Immunology.
