Liesenfeld O, Kosek J C, Suzuki Y
Department of Immunology and Infectious Diseases, Research Institute, Palo Alto Medical Foundation, California 94301, USA.
Infect Immun. 1997 Nov;65(11):4682-9. doi: 10.1128/iai.65.11.4682-4689.1997.
Since we previously observed a remarkable decrease in the numbers of T cells in the Peyer's patches of the small intestines in C57BL/6 mice following peroral infection with Toxoplasma gondii, we performed studies to examine the mechanism(s) whereby this decrease in numbers of the T cells occurs. We found that apoptotic cell death of CD4+ and CD8+ alphabeta T cells occurred in Peyer's patches following infection. Upregulation of Fas expression was observed in these T cells. C57BL/6-background mutant mice which lack functional Fas antigen did not develop apoptosis in their Peyer's patches following infection. Treatment of infected C57BL/6 mice with anti-gamma interferon (IFN-gamma) monoclonal antibodies prevented the upregulation of Fas on their Peyer's patch T cells and inhibited the occurrence of apoptosis of these T cells. These results indicate that IFN-gamma induces Fas-dependent apoptosis in CD4+ and CD8+ alphabeta T cells in Peyer's patches in C57BL/6 mice following peroral infection with T. gondii.
由于我们之前观察到，C57BL/6小鼠经口感染刚地弓形虫后，其小肠派尔集合淋巴结中的T细胞数量显著减少，因此我们开展了研究，以探究T细胞数量减少的机制。我们发现，感染后派尔集合淋巴结中发生了CD4⁺和CD8⁺αβ T细胞的凋亡性细胞死亡。在这些T细胞中观察到Fas表达上调。缺乏功能性Fas抗原的C57BL/6背景突变小鼠在感染后其派尔集合淋巴结中未发生凋亡。用抗γ干扰素（IFN-γ）单克隆抗体处理感染的C57BL/6小鼠，可阻止其派尔集合淋巴结T细胞上Fas的上调，并抑制这些T细胞凋亡的发生。这些结果表明，IFN-γ在C57BL/6小鼠经口感染刚地弓形虫后，诱导派尔集合淋巴结中CD4⁺和CD8⁺αβ T细胞发生Fas依赖性凋亡。
