Altered expression of self-reactive T cell receptor V beta regions in autoimmune mice.
Intrathymic tolerance results in elimination of T cells bearing self-reactive TCR V beta regions in mice expressing certain combinations of I-E and minor lymphocyte stimulatory (Mls) phenotypes. To determine if autoimmune strains of mice have a defect in intrathymic deletion of self-reactive TCR V beta regions, expression of V beta 3, V beta 6, V beta 8.1, and V beta 11 were examined in lpr/lpr and +/+ strains of mice; MRL/MpJ(H-2K, I-E+, Mlsb,), C57BL/6J(H-2b, I-E-, Mlsb,), C3H/HeJ(H-2k, I-E+, Mlsc), AKR/J(H-2k, I-E+, Mlsa); and in autoimmune NZB/N(H-2d, I-E+, Mlsa) and BXSB(H-2b, I-E-, Mlsb) mice. The results suggest that, during intrathymic development, self-reactive T cells are deleted in autoimmune strains of mice as found in normal control strains of mice. However, the TCR V beta repertoire is skewed in autoimmune strains compared to normal strains of mice. For example, MRL-lpr/lpr mice, but not other lpr/lpr strains, had increased expression of V beta 6 relative to expression in control MRL(-)+/+ mice, which is associated with collagen-induced arthritis. These data are consistent with a model of normal affinity for negative selection of self-reactive T cells in the thymus of autoimmune strains of mice followed by expansion of autoreactive T cell clones in the peripheral lymphoid organs. The peripheral lymphoid organs of lpr/lpr mice contain an expanded population of abnormal CD4-, CD8-, 6B2+ T cells. Elimination of self-reactive peripheral T cells suggests that these abnormal cells are derived from a CD4+ subpopulation in the thymus. Flow cytometry analysis of peripheral lymph node T cells from MRL-lpr/lpr mice reveal three populations of CD4+ T cells expressing low, intermediate and high intensity of B220 (6B2). This supports the hypothesis that in lpr/lpr mice, self-reactive CD4+ T cells are eliminated in the thymus, and that these cells lose expression of CD4 and acquire expression of 6B2 in the periphery.
Mountz
J D
JD
Veterans Administration Medical Center, Birmingham, AL 35294.
Smith
T M
TM
Toth
K S
KS
D000818:Animals; D000954:Antigens, Surface / Q000032:analysis; D001327:Autoimmune Diseases / Q000235:genetics / Q000276:immunology*; D005434:Flow Cytometry; D015870:Gene Expression; D017493:Leukocyte Common Antigens; D008285:Major Histocompatibility Complex; D051379:Mice; D008817:Mice, Mutant Strains / Q000235:genetics; D008912:Minor Histocompatibility Loci; D012333:RNA, Messenger / Q000235:genetics; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D016693:Receptors, Antigen, T-Cell, alpha-beta; D013950:Thymus Gland / Q000502:physiology
D000954:Antigens, Surface; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta; D017493:Leukocyte Common Antigens