CCK-8 upregulates B7.1 and B7.2 expressions and enhances the costimulatory activity of murine peritoneal macrophages / 中国病理生理杂志

ABSTRACT

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 -TdR incorporation in a ?-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.