Immune responses to Nippostrongylus brasiliensis and tuberculin protein in GATA-3-transgenic mice

Abstract

GATA-3 appears to be key to the Th2 response. However, few in vivo experiments have examined the function of GATA-3 in Th1 and Th2 immune responses. We developed two lines of GATA-3-transgenic (Tg) mice harboring the SRα or lck promoters and examined the Th2 immune responses of mice infected with the intestinal nematode Nippostrongylus brasiliensis and the Th1 responses with purified derivative of tuberculin (PPD) immunization. Numbers of peripheral blood eosinophils in all GATA-3-Tg mice increased 10- to 20-fold after primary infection with N. brasiliensis and 25–100-fold after secondary infection. The number of eosinophils in infected GATA-3-Tg mice was significantly higher than that in infected control littermates. Total IgE levels after primary infection in GATA-3-Tg mice were 8–450-fold increased, which was significantly higher than those of control mice. Mesenteric lymph node cells of infected GATA-3-Tg mice upon stimulation with N. brasiliensis antigen secreted more IL-5 and IL-13 than those of control mice. However, production of IL-4 and IFN-γ were comparable between GATA-3-Tg and controls. Mice immunized with PPD were intradermally challenged with PPD to induce delayed type hypersensitivity (DTH). The amount of footpad swelling caused by the DTH reaction in GATA-3-Tg mice was significantly smaller than that of control littermates. Inguinal lymph node cells from GATA-3-Tg mice stimulated with PPD in vitro secreted more IL-5, IL-10 and less IFN-γ than those of control littermates. These results suggested that Th1 and Th2 driven conditions enhance IL-5 production in GATA-3-Tg mice through the direct binding of GATA-3 to the IL-5 promoter region. The influence of GATA-3 on IL-13, IFN-γ and IL-10 production varied according to the stimulating conditions. However, IL-4 production was not significantly elevated in GATA-3-Tg mice, indicating that IL-4 and IL-5 production was differentially regulated in these mice.