In vivo tolerance induction and associated cytokine production by subsets of murine CD4+ T cells

Male BXSB mice develop lupus-like disease and die early in life (4 to 5 mo) whereas female mice do not. Others have demonstrated that CD4+ cells from male mice support B cell resistance to tolerance induction to human gamma-globulin (HGG). In this study, male and female mice tolerized at 2 mo of age with deaggregated HGG and subsequently immunized with HGG in comparison with mice immunized only were tested for anti-HGG Ab responses. CD4+ cells from draining lymph nodes of these mice were tested in culture for proliferation and production of cytokine mRNA and protein in response to HGG plus APC. Tolerized male but not female mice produced anti-HGG Abs of both the IgG1 and IgG2a isotypes. HGG-stimulated CD4+ cells from immunized male and female mice that were not tolerized produced IL-2, IL-4, IL-5, IFN-gamma, and TNF-beta mRNA as well as IL-2 and IL-4 protein, whereas tolerized, immunized mice of both sexes failed to proliferate or produce either IL-2 or IL-4 or express any cytokine mRNA in response to HGG in vitro. A resistance in tolerance induction in male mice, as determined by anti-HGG Abs, was also observed at 3 mo of age. Although a resistance to tolerance was also seen in terms of proliferation in the 3-mo-old males, production of IL-2 or IL-4 protein was still not observed. Thus, all T cell subsets identified by cytokine expression profiles were tolerized not only from females but also from males, of which the latter appeared to show some resistance to tolerance induction.