Objective To investigate the function characteristics of CD4 T cell converted double negative T cell and provide a basis for further insight into the characteristics of mouse converted double negative T cell.Methods The gene expression profile was analyzed by transcriptome sequencing and protein mass spectrometry.The expression of cell active marker CD44,CD69 and OX40 was investigated by flow cytometry and the cytotoxicity of mouse double negative T cell was verified by CFSE staining.Results Mouse CD4 T cell converted double negative T cell expressed cell phenotype that differed from other mature CI4 T cells.Mouse converted double negative T cell expressed high level of active marker of CD44,CD69 and OX40.Cytotoxicity of PrfO DN T was significantly reduced.Conclusions Mouse CD4 T cell converted double negative T cell has distinguishing cell phenotypes,that are not identical to other mature CD4 T cells.Mouse double negative T cell overexpresses cell activation marker and cytotoxic cytokines.The immune suppressive function of mouse double negative T cell is mainly dependent on perforin pathway.

Objective To explore the effect of lymphocytes on the innate immune cells in Rag1 and Rag2/IL2rγ gene knockout mice after hepatic ischemia and reperfusion injury (HIRI).Methods C57BL/6 mice (n =10),Rag1 knockout mice (n =10) and Rag2/IL2rγ knockout mice (n =10) were respectively divided into sham group and hepatic ischemia-reperfusion injury group by simple randomization,5 mice in each group.By using the model of hepatic ischemia-reperfusion injury in mice,changes of intrahepatic immune cells were detected by flow cytometry.Hepatic ischemia and reperfusion injury and changes of intrahepatic cell subsets were observed in immune system-deficient mice,both Rag1 and Rag2/IL2rγ knockout.Measurement data were expressed as ((x) ±s),and analyzed using independent samples t test.Results Flow cytometry results showed that immune cells,including NK cells,NKT cells,CD4+T cells,DNT cells,Kupffer cells,BMMs and neutrophils were increased after HIRI.Compared with sham group,Rag1 knockout mice displayed markedly increased proportion of Kupffer cells,BMMs and neutrophils after HIRI.And decreased serum ALT levels [from (1 776.25 ± 219.37) U/L to (932.33 ±58.77) U/L,P=0.003,t =7.350] and less hepatocellular necrosis were exhibited in Rag1 knockout mice after HIRI,comparing to C57BL/6 HIRI group.In addition,increased neutrophils were still observed in Rag2/IL2rγ knockout mice after HIRI,without increased proportion of Kupffer cells and BMMs.Compared with Rag1 knockout mice,ALT levels were further decreased from (932.33 ± 58.77) U/L to (309.00 ± 163.53) U/L (P=0.002,t =6.182) in Rag2/IL2rγ knockout mice.Conclusion Both Rag1 and Rag2/IL2rγ knockout mice exhibite less liver injury after HIRI comparing with C57BL/6 mice,indicating that T cells and NK cells aggravate the liver injury.Moreover,T cells do not affect the recruitment of Kupffer cells,BMMs and neutrophils,but regulate the recruitment of NK cells,while NK cells contribute to the activation of Kupffer cells and BMMs,but not neutrophil influx.