Chan M M
Department of Biological Sciences, Rutgers, State University of New Jersey, Piscataway 08855-1059.
Eur J Immunol. 1993 May;23(5):1181-4. doi: 10.1002/eji.1830230532.
The immune response to Leishmania major has been the subject of many investigations. However, Leishmania includes many species with different clinical manifestations. In this report, we studied the T cell response to L. mexicana amazonensis, a New World species, in a murine model. We found that, similar to L. major, an Old World species, resistant C57BL/6 mice produced a high level of IFN-gamma and a low level of IL-4. Conversely, susceptible BALB/c mice produced a much lower level of IFN-gamma and higher level of IL-4. Although IFN-gamma is one of the important lymphokines that mediate macrophage activation and thus the destruction of the intracellular parasites, which lymphocyte subsets are producing the IFN-gamma is still a controversy. Much evidence including the isolation of protective, IFN-gamma-producing, CD4+ cell lines have confirmed the participation of CD4+ Th1 cells unequivocally. However, both CD4+ and CD8+ cells produced IFN-gamma. Recently, an increasing body of evidence has appeared suggesting that CD8+ cells also play a role in the resolution of murine L. major infection. We found that in the L. m. amazonensis model, when CD8+ lymphocytes from resistant C57BL/6 mice were eliminated by anti-CD8 antibody and complement-mediated lysis, the IFN-gamma production was reduced by 77%. This indicated that CD8+ cells produced a significant amount of the IFN-gamma. However, our results also indicate that IFN-gamma production by CD8+ cells was dependent on CD4+ cells.
对硕大利什曼原虫的免疫反应一直是众多研究的主题。然而，利什曼原虫包括许多具有不同临床表现的物种。在本报告中，我们在小鼠模型中研究了对墨西哥利什曼原虫亚马逊亚种（一种新大陆物种）的T细胞反应。我们发现，与旧大陆物种硕大利什曼原虫类似，具有抗性的C57BL/6小鼠产生高水平的干扰素-γ和低水平的白细胞介素-4。相反，易感的BALB/c小鼠产生的干扰素-γ水平低得多，而白细胞介素-4水平高得多。虽然干扰素-γ是介导巨噬细胞活化从而破坏细胞内寄生虫的重要淋巴因子之一，但产生干扰素-γ的淋巴细胞亚群仍存在争议。包括分离出具有保护性、产生干扰素-γ的CD4+细胞系在内的许多证据明确证实了CD4+ Th1细胞的参与。然而，CD4+和CD8+细胞都能产生干扰素-γ。最近，越来越多证据表明CD8+细胞在小鼠硕大利什曼原虫感染的消退中也发挥作用。我们发现在墨西哥利什曼原虫亚马逊亚种模型中，当用抗CD8抗体和补体介导的溶解作用清除抗性C57BL/6小鼠的CD8+淋巴细胞时，干扰素-γ的产生减少了77%。这表明CD8+细胞产生了大量的干扰素-γ。然而，我们的结果也表明CD8+细胞产生干扰素-γ依赖于CD4+细胞。
