Unresponsiveness of CD4+ T cells from a non-responder strain to HgCl2 is not due to CD8(+)-mediated immunosuppression: an analysis of the very early activation antigen CD69.
Injections of HgCl2 lead to autoimmune manifestations in genetically predisposed rats and mice. In this study, the authors examined the responsiveness of T subsets from different mouse strains to HgCl2 by tracing their expression of the very early activation antigen CD69. The authors found increased expression of the CD69 antigen on CD4+ T cells from the responder A.SW and BALB/c mice, but not on CD4+ T cells from the non-responder DBA/2 mice, indicating an activation of T helper cells in the responder strains. However, the CD69 antigen was induced on CD8+ T cells from all strains irrespective whether they were susceptible or resistant to mercury-induced autoimmunity. Since CD8+ T cells have been described as mediating immunosuppression and as being responsible for the resistance to autoimmune induction by mercury, the authors tested whether CD8+ T cells inhibited the activation of CD4+ T cells by HgCl2 in the non-responder strains. However, there was no evidence for a suppressive role of CD8+ T cells from the DBA/2 mice in the response to HgCl2. The findings indicate that T helper cells play a central role in the immunological effects of HgCl2 and unresponsiveness of T helper cells in the nonresponder strains is not due to CD8(+)-mediated immunosuppression.
Jiang
Y
Y
Department of Immunology, Wenner-Gren Institute, Arrhenius Laboratories for Natural Sciences, Stockholm University, Sweden.
Möller
G
G
D000818:Animals; D015703:Antigens, CD / Q000276:immunology*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D002478:Cells, Cultured; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology*; D037181:Lectins, C-Type; D008627:Mercuric Chloride / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D010641:Phenotype; D013154:Spleen / Q000166:cytology; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D037181:Lectins, C-Type; D008627:Mercuric Chloride; D000099192:CD69 Antigens