title: CD4+ T cells from lupus-prone mice avoid antigen-specific tolerance induction in vivo.
abstract: Activated T cells in spontaneous lupus presumably bypass normal tolerance mechanisms in the periphery, since thymic tolerance appears intact. To determine whether such T cells indeed avoid in vivo peripheral tolerance mechanisms, we assessed their activation and recall responses after in vivo Ag stimulation in the absence of exogenously supplied costimulatory signals. Naive CD4(+) AND (transgenic mice bearing rearranged TCR specific for pigeon cytochrome c, peptides 88-104) TCR-transgenic T cells, specific for pigeon cytochrome c, from lupus-prone Fas-intact MRL/Mp+(Fas-lpr) and from H-2(k)-matched control CBA/CaJ and B10.BR mice (MRL.AND, CBA.AND, and B10.AND, respectively) were adoptively transferred into (MRL x CBA)F(1) or (MRL x B10)F(1) recipients transgenically expressing membrane-bound pigeon cytochrome c as a self-Ag. MRL.AND and control CBA.AND and B10.AND-transgenic T cells were activated and divided after transfer, indicating encounter with their cognate Ag; however, T cells from CBA.AND and B10.AND mice were impaired in their ability to proliferate and produce IL-2 after challenge with pigeon cytochrome c in ex vivo recall assays, a typical phenotype of anergized cells. By contrast, MRL.AND T cells proliferated more, and a significantly higher percentage of such cells produced IL-2, compared with control T cells. This observation that MRL T cells avoided anergy induction in vivo was confirmed in an in vitro system where the cells were stimulated with an anti-CD3 in the absence of a costimulatory signal. These experiments provide direct evidence that CD4(+) T cells from Fas-intact lupus-prone MRL mice are more resistant than nonautoimmune control cells to anergy induction. Anergy avoidance in the periphery might contribute to the characteristic finding in lupus of inappropriate T cell activation in response to ubiquitous self-Ags.
authors.affiliation: Department of Medicine, Section of Rheumatology, Yale School of Medicine, New Haven, CT 06520, USA.
authors.forename: Farida
authors.initials: F
authors.lastname: Bouzahzah
authors.forename: Sungsoo
authors.initials: S
authors.lastname: Jung
authors.forename: Joseph
authors.initials: J
authors.lastname: Craft
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D001324:Autoantigens / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism* / Q000637:transplantation; D002455:Cell Division / Q000235:genetics / Q000276:immunology; D002469:Cell Separation; D002478:Cells, Cultured; D017635:Clonal Anergy / Q000235:genetics / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D020022:Genetic Predisposition to Disease; D008181:Lupus Nephritis / Q000235:genetics / Q000276:immunology*; D018655:Lymphocyte Count; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D019463:Mice, Inbred MRL lpr; D008822:Mice, Transgenic; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics
chemical_list: D001324:Autoantigens; D018984:Epitopes, T-Lymphocyte; D016693:Receptors, Antigen, T-Cell, alpha-beta