Tanaka T, Hamada T, Inoue N, Nagasawa H, Fujisaki K, Suzuki N, Mikami T
The Research Center for Protozoan Molecular Immunology, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, 080-8555, Hokkaido, Japan.
Vet Parasitol. 2000 Jun 27;90(3):183-91. doi: 10.1016/s0304-4017(00)00238-7.
The role of CD4(+) or CD8(+) T cells in the immune response of BALB/c mice against Neospora caninum infection was examined by using anti-CD4 and/or anti-CD8 monoclonal antibodies (mAbs). Mice were intraperitoneally inoculated with anti-CD4 and/or anti-CD8 mAbs before and after infection with N. caninum and observed for 30 days after infection. Most of the anti-CD4 mAb-treated mice and all of the anti-CD4 and anti-CD8 mAbs-treated mice died within 30 days post-infection (p.i.). In contrast, 100% of PBS-treated mice and 70% of anti-CD8 mAb-treated mice survived more than 30 days. When compared with phosphate-buffered saline (PBS)-treated mice, the weight of mice treated with mAbs tended to decrease. From these results CD4(+) T cells, but not CD8(+) T cells, have an important role for protection of mice against N. caninum infection. Serum antibody levels to N. caninum in infected-mice treated with anti-CD4 mAb or a mixture of anti-CD4 and anti-CD8 mAbs were lower than those in the infected mice treated with anti-CD8 mAb or PBS. The mice treated with anti-interferon-gamma (IFN-gamma) mAb produced high antibody levels to N. caninum, but all mice died within 18 days p.i. These results indicated that IFN-gamma is an important cytokine for protection against N. caninum infection at the early stage of infection. However, since CD4(+) T cells against N. caninum were essential to the production of specific antibody, these antibodies might have important roles in host protection at the later stage of infection.
通过使用抗CD4和/或抗CD8单克隆抗体（mAb），研究了CD4(+)或CD8(+) T细胞在BALB/c小鼠抗犬新孢子虫感染免疫反应中的作用。在犬新孢子虫感染前后，给小鼠腹腔注射抗CD4和/或抗CD8 mAb，并在感染后观察30天。大多数抗CD4 mAb处理的小鼠以及所有抗CD4和抗CD8 mAb处理的小鼠在感染后30天内死亡。相比之下，100%的磷酸盐缓冲盐水（PBS）处理的小鼠和70%的抗CD8 mAb处理的小鼠存活超过30天。与PBS处理的小鼠相比，mAb处理的小鼠体重有下降趋势。从这些结果可知，CD4(+) T细胞而非CD8(+) T细胞在保护小鼠抵抗犬新孢子虫感染中起重要作用。用抗CD4 mAb或抗CD4和抗CD8 mAb混合物处理的感染小鼠血清中犬新孢子虫抗体水平低于用抗CD8 mAb或PBS处理的感染小鼠。用抗干扰素-γ（IFN-γ）mAb处理的小鼠产生了高水平的犬新孢子虫抗体，但所有小鼠在感染后18天内死亡。这些结果表明，IFN-γ是感染早期抵抗犬新孢子虫感染的重要细胞因子。然而，由于针对犬新孢子虫的CD4(+) T细胞对于特异性抗体的产生至关重要，这些抗体可能在感染后期的宿主保护中起重要作用。
