中文摘要：

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^-6mol／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4：1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24h）共同体外培养，同时加入ConA5mg／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^-7mol／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。

英文摘要：

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 13 - 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.