No evidence for emergence of autoreactive V beta 6+ T cells in Mls-1a mice following exposure to a thymotoxic dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin.
Tolerance to minor lymphocyte stimulatory-1a (Mls-1a) antigens is associated with clonal deletion of cells carrying the T cell receptor variable region V beta 6. Thymic epithelial cells may contribute to the intrathymic negative selection of potentially autoreactive V beta 6+ cells. Because 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) acts on thymic epithelial cells, we hypothesized that it may interfere with intrathymic selection processes. In the present study, this was addressed by exposing Mls-1a DBA/2 mice to a single thymotoxic dose of TCDD. The emergence of V beta 6+ cells in thymus, spleen, and mesenteric lymph nodes was investigated during the subsequent recovery of TCDD-induced thymic atrophy. In addition, the extrathymic differentiation of T lymphocytes in the liver was studied. TCDD exposure resulted in a severe thymic atrophy, and an increase in hepatic mononuclear cells. However, we were not able to demonstrate any emergence of potentially autoreactive mature V beta 6+ T cells, that differentiated either intrathymically or extrathymically, in TCDD-exposed DBA/2 mice.
de Heer
C
C
Laboratory for Pathology, National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands.
van Driesten
G
G
Schuurman
H J
HJ
Rozing
J
J
van Loveren
H
H
D000818:Animals; D015551:Autoimmunity / Q000187:drug effects*; D017637:Clonal Deletion / Q000187:drug effects; D005260:Female; D005434:Flow Cytometry; D008099:Liver / Q000187:drug effects / Q000276:immunology; D008198:Lymph Nodes / Q000187:drug effects / Q000276:immunology; D008297:Male; D008643:Mesentery; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D016747:Minor Lymphocyte Stimulatory Antigens / Q000276:immunology*; D009929:Organ Size / Q000187:drug effects; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology*; D013154:Spleen / Q000187:drug effects / Q000276:immunology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D013950:Thymus Gland / Q000187:drug effects* / Q000276:immunology
D016747:Minor Lymphocyte Stimulatory Antigens; D000072317:Polychlorinated Dibenzodioxins; D016693:Receptors, Antigen, T-Cell, alpha-beta