CCK-8上调小鼠腹腔巨噬细胞B7.1和B7.2表达并增强其协同刺激活性

目的： 探讨八肽胆囊收缩素（CCK-8）对静息巨噬细胞B7.1和B7.2表达及其协同刺激功能的影响。方法：用CCK-8（10-12-10-6 mol/L）孵育小鼠腹腔巨噬细胞一定时间，采用流式细胞术分析细胞表面B7.1和B7.2含量的变化。用免疫磁珠从小鼠脾细胞分离CD4+T细胞，按4∶〖KG-*2〗1数量比与腹腔巨噬细胞（预先用CCK-8和/或抗B7.1抗体、抗B7.2抗体、CCK1R拮抗剂CR1409、CCK2R拮抗剂CR2945孵育24 h）共同体外培养，同时加入ConA 5 mg/L，采用［3H］掺入法测定CD4+T细胞增殖反映巨噬细胞的协同刺激活性。结果：CCK-8可上调静息巨噬细胞B7.1及B7.2的表达，并增强巨噬细胞的协同刺激活性。CCK-8的作用呈剂量依赖性，最大效应剂量是在10-9-10-7 mol/L之间。抗B7.2抗体可减轻CCK-8增强巨噬细胞协同刺激活性的作用，CR1409及CR2945均能逆转CCK-8的上述作用，且CR1409的作用较CR2945更明显。结论：CCK-8通过上调巨噬细胞B7.2表达而增强其协同刺激活性，该作用由CCK1R及CCK2R介导，其中CCK1R起主要介导作用。

CCK-8 upregulates B7.1 and B7.2 expressions and enhances the costimulatory activity of murine peritoneal macrophages

AIM: To investigate in vitro effects of cholecystokinin octapeptide(CCK-8) on the expressions of B7.1 and B7.2 and the costimulatory activity of T lymphocytes in unstimulated macrophages.METHODS: Mouse peritoneal macrophages were isolated and incubated with CCK-8（10-12-10-6 mol/L） for indicated time. The B7.1 and B7.2 expressions of murine peritoneal macrophages were analyzed by flow cytometry. CD4+T cells were isolated from mouse spleen using immunomagnetic beads, and cultured with 1/4 numbers of macrophages which were pretreated with CCK-8 and/or anti-B7.1 antibody, anti-B7.2 antibody, CCK1R antagonist CR1409, CCK2R antagonist CR2945 for 24 h. ConA was added into the culture medium to stimulate CD4+T cell proliferation. The proliferation was determined by measuring ［3H］-TdR incorporation in a β-scintillation counter. RESULTS: B7.1 and B7.2 expressions and costimulatory activity of peritoneal macrophages were enhanced by CCK-8 in a dose-dependent manner, and the maximal effects occurred at the concentrations of 10-9 mol/L to 10-7 mol/L. Anti-B7.2 antibody, but not anti-B7.1 antibody, reduced the modulatory role of CCK-8 on costimulatory activity. Both CR1409 and CR2945 reversed the effect of CCK-8 on costimulation, and the role of CR1409 was more significant. CONCLUSION: CCK-8 enhances macrophage costimulatory activity by upregulating B7.2 expression, which is mediated by CCK1R and CCK2R. CCK1R might be the major receptor responsible for the modulation of CCK-8 on costimulation.