P38 Immunoregulatory effects and mechanisms of four Milk-borne probiotics in immunocompromised Balb/c mice

Abstract

Objective: We demonstrated that immune active peptides isolated from shubat could promote the proliferation of mice spleen lymphocytes. This effect was related to regulation of the Th1/Th2 balance. We wanted to investigate four probiotics from Xinjiang traditional fermented camel milk (shubat) and cheese whey, to examine their immunoregulatory mechanisms and determine their signalling pathways. Methods: 1. The four probiotics were cultured and suspensions prepared. 2. An immunocompromised model (Balb/c mice) was induced with cyclophosphamide. 3. Mice were randomly divided into eleven groups, given high and low dose suspensions of four probiotics. 4. Determination index: calculate indexes of spleen, thymus, colon. Detect spleen lymphocyte activity, serum ALT, AST, CREA, and UREA. 5. Detect serum cytokine levels with CBA kit. 5. Gene expression: use RT-PCR to detect the mRNA expression of five genes. Results: 1. The spleen index was significantly increased. 2. The levels of AST, ALT and UREA were reduced. 3. Probiotic groups had significantly increased levels of IL-2, IFN-γ, significantly reduced IL-6, IL-10, IL-17A. 4. RT-PCR results: the probiotic groups were significantly decreased. Conclusion: The four probiotics can increase the body weight, maintain normal liver and kidney function and improves the spleen index, (lymphocyte activity). We concluded that probiotics from shubat can work through a MyD88-dependent TLR-7 signal pathway and have some protective effects. Acknowledgements Funding from The National Natural Science Fund of China (81160344).