摘要目的 研究副干酪乳杆菌丝氨酸蛋白酶编码基因prtP对小鼠肠道免疫调节作用的影响.方法 BALB/c雌性小鼠随机分7组:PBS对照组、副干酪乳杆菌亲本株( Lactobacillus paracasei, Lp)、prtP缺失突变株(Lp△prtP)及回复株 ReLp△prtP 对应的高、中剂量组(1×109CFU/ml、5×108 CFU/ml)连续灌胃0~21 d后对免疫器官指数、脾脏淋巴细胞转化试验、巨噬细胞能量代谢水平、腹腔巨噬细胞吞噬能力、细胞因子、脾脏CD11c+、CD80+有核细胞数进行检测.结果 与prtP基因缺失突变株相比,副干酪乳杆菌亲本株能显著提高小鼠脾脏淋巴细胞转化率、腹腔巨噬细胞的能量代谢水平以及腹腔巨噬细胞吞噬能力,能显著提高血清中 IFN-α、IL-10、IFN-γ的表达,显著提高 CD11c+、CD80+双阳性细胞数量.结论 副干酪乳杆菌对肠道免疫功能的促进作用与prtP基因有关.

abstractsObjective To study the role of serine protease encoding gene prtP carried by Lactoba-cillus paracasei (Lp) in regulating mouse intestinal immunity. Methods Female BALB/c mice were ran-domly divided into seven groups and respectively administered with PBS, medium (5×108CFU/ml) and high dose (1×109CFU/ml) of Lp, Lp△prtP and ReLp△prtP for 21 consecutive days by intragastric ga-vage. Parameters including immune organ index, splenic lymphocyte transformation rate, energy metabolism in celiac macrophages, phagocytic ability of celiac macrophages and cytokines were detected. Quantitative changes in CD11c+CD80+cells in culture supernatants of splenic mononuclear cells were analyzed by flow cytometry. Results Compared with Lp△prtP, Lp could significantly promote the natural transformation of splenic lymphocytes, increase the level of energy metabolism in celiac macrophages, enhance the phagocytic ability of celiac macrophages, and up-regulate the expression of IFN-α, IL-10 and IFN-γ and the percentage of CD11c+CD80+cells. Conclusion Serine protease encoding gene prtP in Lp can regulate the mucosal im-mune system in mice.