NRAMP-1 GENE ASSOCIATED WITH THE INDUCTION OF IMMUNE RESPONSES AND THE EXPRESSION OF RESISTANCE AGAINST MYCOBACTERIAL INFECTION

探讨了Nramp-1基因与小鼠分枝杆菌病细胞因子产生的关系。本研究选用C57BL/6(NRAMP-1、S)及其卡介苗同源基因(NRAMP-1、R)小鼠。首先检测了巨噬细胞在结核分枝杆菌或结核分枝杆菌刺激下分泌的两种细胞因子IL-10和IL-12的产生。鸟型支原体感染早期诱导的细胞因子谱比结核分枝杆菌更明显。禽支原体刺激NRAMP-1、S巨噬细胞产生IL-10的水平高于NRAMP-1、R巨噬细胞。结核分枝杆菌刺激后，NRAMP-1、S和NRAMP-1的巨噬细胞产生IL-12的能力均无明显差异。我们的结果表明，NK细胞可能是产生干扰素-γ的主要来源，并有助于诱导感染细胞内支原体的小鼠的免疫反应，尽管它们是NRAMP-1基因。

The relationship between Nramp-lgene and cytokine production in murine mycobacteriosis was examined. C57BL/6 (NRAMP-1^s) and their Bcg congenic (NRAMP-1^r) mice were used in these studies. Initially the production of two cytokines- interleukin-10 (IL-10) and IL-12, which are secreted by macrophages after Mycobacterium (M).avium or M.tuberculosis stimulation, was examined. The cytokine profiles induced in the early phase of the M.avium infection were more distinct than those of M.tuberculosis. NRAMP-1^s macrophages produced higher level of IL-10 as compared with NRAMP-1^r macrophages when they were stimulated with M.avium. In contrast, lower level of IL-12 production was recognized in NRAMP-1^s as compared with NRAMP-1^r. Stimulation with M.tuberculosis failed to produce significant difference in the production of these two cytokines by the macrophages of both NRAMP-1^s and NRAMP-1^r. The effect of NRAMP-1 gene on the functions of natural killer (NK) cells in M.intracellulare-infected mice was also studied. Our results indicateded that NK cells might be a main source of IFN-γ production and contribute the induction of immune responses in M.intracellulare- infected mice despite their NRAMP-1 genotype.