Hiyama K, Hamano S, Nakamura T, Nomoto K, Tada I
Department of Parasitology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Parasitol Res. 2001 Apr;87(4):269-74. doi: 10.1007/pl00008577.
The role of IL-4 has often been studied, especially in the Leishmania major infection model, but not in Trypanosoma cruzi infection. In the present study, the role of IL-4 in host defense against infection with the Tulahuen strain of T. cruzi was examined by depleting IL-4 with an anti-IL-4 monoclonal antibody in vivo. In both IL-4 depleted and control C57BL/6 mice, the parasitemia showed peaks on the 21st day of infection. Both parasitemia and mortality were decreased in IL-4 depleted mice compared with control mice when IFN-gamma and nitric oxide productions were increased in IL-4 depleted mice compared with control mice. The mice treated with N-nitro-L-arginine methyl ester, a competitive inhibitor of nitric oxide synthase, showed increased susceptibility to T. cruzi infection to the same level in both IL-4 depleted and control mice. Thus, it is suggested that endogenous IL-4 induces susceptibility to T. cruzi mainly by suppressing the production of IFN-gamma and nitric oxide, which has trypanocidal activity.
白细胞介素-4（IL-4）的作用已被广泛研究，尤其是在硕大利什曼原虫感染模型中，但在克氏锥虫感染方面尚未有研究。在本研究中，通过在体内用抗IL-4单克隆抗体清除IL-4，研究了IL-4在宿主抵抗克氏锥虫图拉亨株感染中的作用。在IL-4清除组和对照C57BL/6小鼠中，寄生虫血症在感染后第21天达到峰值。与对照小鼠相比，IL-4清除组小鼠的寄生虫血症和死亡率均降低，同时IL-4清除组小鼠中γ干扰素（IFN-γ）和一氧化氮的产生较对照小鼠增加。用一氧化氮合酶竞争性抑制剂N-硝基-L-精氨酸甲酯处理的小鼠，在IL-4清除组和对照小鼠中对克氏锥虫感染的易感性均增加到相同水平。因此，提示内源性IL-4主要通过抑制具有杀锥虫活性的IFN-γ和一氧化氮的产生，诱导对克氏锥虫的易感性。
