Yang J, Kawamura I, Mitsuyama M
Department of Bacteriology, Niigata University School of Medicine, Japan.
Infect Immun. 1997 Jan;65(1):72-7. doi: 10.1128/iai.65.1.72-77.1997.
Protective immunity of mice against Listeria monocytogenes, which is mediated mainly by gamma interferon (IFN-gamma)-producing T cells, was induced by immunization with viable bacteria but not with killed bacteria. By comparing mice immunized with either viable or killed L. monocytogenes, it was found that IFN-gamma was produced at the initial stage only after immunization with viable bacteria. This finding prompted us to investigate the effect of neutralizing the IFN-gamma on the final generation of protective T cells against L. monocytogenes. When endogenous IFN-gamma was neutralized by administration of anti-IFN-gamma monoclonal antibody for the initial 2 days in mice immunized with viable bacteria, the generation of protective T cells on day 6 was completely blocked, as revealed by T-cell adoptive transfer. The generation of listeria-specific IFN-gamma-producing T cells was also abolished. These results clearly demonstrated that endogenous IFN-gamma, which is produced at the initial stage of immunization, actually plays a critical role in the generation of protective T cells against L. monocytogenes in vivo. Moreover, this study suggested that the lack of IFN-gamma-inducing ability is responsible for the inability of killed L. monocytogenes to induce protective T cells in mice.
小鼠对单核细胞增生李斯特菌的保护性免疫主要由产生γ干扰素（IFN-γ）的T细胞介导，通过用活细菌免疫可诱导产生，但用死细菌免疫则不能。通过比较用活的或死的单核细胞增生李斯特菌免疫的小鼠，发现仅在用活细菌免疫后的初始阶段产生了IFN-γ。这一发现促使我们研究中和IFN-γ对针对单核细胞增生李斯特菌的保护性T细胞最终生成的影响。在用活细菌免疫的小鼠中，在最初2天通过给予抗IFN-γ单克隆抗体来中和内源性IFN-γ，如通过T细胞过继转移所显示的，第6天保护性T细胞的生成被完全阻断。产生李斯特菌特异性IFN-γ的T细胞的生成也被消除。这些结果清楚地表明，在免疫初始阶段产生的内源性IFN-γ实际上在体内针对单核细胞增生李斯特菌的保护性T细胞生成中起关键作用。此外，这项研究表明，缺乏IFN-γ诱导能力是死的单核细胞增生李斯特菌不能在小鼠中诱导保护性T细胞的原因。
