CD4 and infection: In another study, it was shown that CD4+ T cells with an inducible regulatory phenotype (CD4+CD25+FoxP3-T-bet+CTLA4high) produced IFNγ and IL-10 in the infection of C3H/HeN mice with a lethal dose of R. conorii and that these cells suppressed proliferation and IL-2 release by CD4+ T cells in vitro [120].