Role of Toll‐Like Receptor 4 in Legionella pneumophila infection with C3H/HeJ Mouse Model

Abstract

ObjectiveTo explore the relationship between TLR4 and Legionella infection in a mouse model.MethodsC3H/HeJ and C3H/HeN mice were used as experimentl animal. Infection group and contol group were tracheal injection of bacterial suspension or sterile saline nasal respectively. All mice were sacrificed at 12h, 24h, 48h, 72h respectively. Left lung upper lobe was taken to do fixed biopsy. TLR4 protein expression level of each group on PBMC were detected by flow cytometry.ResultsPathological examination showed that the C3H/HeJ and C3H/HeN infection group in lung tissue were showed infiltration of inflammatory cells and alveolar vascular bleeding, the control group was not found inflammatory reaction. Legionella pneumonia model established successfully. There was significantly difference of TLR4 protein expression in three groups, each timing and the interaction of groups and timing(P<0.001). Comparison between groups found that C3H/HeJ infection group and C3H/HeN infection group, C3H/HeJ infection group and C3H/HeN control group shows statistical significance(P<0.001). But C3H/HeN infection group and C3H/HeN control group had no statistical significance(P>;0.05).ConclusionThe TLR4 gene mutations make it low reaction to Legionella. However, the anti‐inflammatory effects of TLR4 to Legionella needs further study.This study was supported by the National Natural Science Funds of China (grant no. 30872154)