ABSTRACT
Objective 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.