The Mechanism Of Macrophages Autophagy In Anti-candida Albicans Immunity

Objective 1.To study the dynamic changes and phagocytosis of myeloid cells in two models of C.albicans intraperitoneal infection and intravenous infection,and to initially explore the myeloid cell population and the main phagocytic cell population that play the main role of antibacterial at different stages of infection;2.To explore the mechanism of autophagy in the process of macrophages against C.albicans infection.Method 1.The intraocular canthal intravenous injection of C.albicans was used to construct a venous infection model.An abdominal infection model was established by intraperitoneal injection of Candida albicans.At different infection time points,lung cells or peritoneal lavage fluid were taken,and flow cytometry was used to detect neutrophils,macrophages and dendritic cells,which shows the kinetics of cells and the proportion of each cell population in the phagocytic cells;2.Bone marrow-derived macrophages(BMDM)were infected by C.albicans in vitro,and intracellular autophagy was detected by western blot,and the phagocytosis rate of BMDM cells was detected by flow cytometry.The production of reactive oxygen species(ROS)and the proliferation of fungi were compared between the BMDMs of wild-type(WT)and Atg5 knockout.3.We use RNA-seq technology to screen the genes and functions that are affected by the blocking of autophagy at different time points of infection when macrophages are infected by C.albicans at different time points.Results 1.Regardless of the intravenous infection model or the abdominal cavity infection model,the proportions of neutrophils and macrophages were higher than dendritic cells,and 60%of the phagocytic cells in the early stage(4h)were neutrophils.In the later stage of infection(24h),macrophages account for about 60%of the phagocyte population.2.C.albicans caused an increase in the expression of autophagy-related proteins in BMDMs After blocking autophagy,compared with the WT group,the Atg5 knockout BMDMs phagocytic ratio and ROS production level increased,and the ability to inhibit fungal proliferation was enhanced,And a higher concentration of MG-132 is required to block the proteasome.3.RNA-seq data showed that genes related to innate immune activation and macrophage function were up-regulated in the early stage of infection,genes related to antibacterial were up-regulated in the middle stage,and genes related to sterilization and negative regulation were up-regulated in the later stage.Conclusion In the process of C.albicans infection,neutrophils and macrophages are the main antibacterial cell populations,and granulocytes perform the main phagocytic tasks in the early stage,while macrophages are the main phagocytic cells in the late stage of infection.C.albicans infection induces autophagy in BMDMs.After blocking autophagy,it can improve the phagocytic,antibacterial and bactericidal abilities of BMDMs and reduce the sensitivity of the proteasome inhibitor MG-132.Blocking autophagy upregulates the inflammatory pathway genes of BMDM cells and affects genes with different functions at different time points of infection.