The relationship between Salmonella plasmid virulence genes and dendritic cells autophagy, apoptosis and immune regulation

摘要

@@Objective: To study the influence of Salmonella plasmid virulence genes (spv) on autophagy, apoptosis and immune function of dendritic cells (DCs), and explore the molecular mechanisms by cell and animal model, respectively. Methods:1. The in vitro experiment using a cell model. Salmonella typhi ST8 carrying spv gene is the object of this study. Salmonella typhimurium SR-11 containing spv gene was used as a positive control, and Salmonella typhi ST10 as a negative one. 3 strains were co-cultured with mouse bone marrow derived DCs (BMDCs). Another group of BMDCs were treated with an autophagy agonist rapamycin (RAPA) overnight before adding bacteria, and the uninfected BMDCs were used as control. BMDCs in each group were harvested at different time points, and Beclin-1 was detected by Western blot; Caspase-3 activity was assayed by colorimetry; the apoptosis rate, endocytosis rate and the expression of co-stimulatory molecules were determined by flow cytometry; the proliferation of CD4+ and CD8+ naive T cells stimulated with BMDCs were detected by mixed lymphocyte reaction; IL-12, IFN-y and IL-10 secretions were assayed by ELISA; the survival rate of BMDCs was determined by trypan blue stain and the viable bacterial quantities inside BMDCs were detected by plate count method.