Effect of Med1 on T cell development and CD4 + T cell differentiation in immune response

The differentiation of CD4 T cells is regulated by a complex and fine signaling pathway composed of many molecules during immune response, and the molecular mechanism for regulating T-bet expression is unclear. Mediator complex subunit 1 (Med1) can combine with a variety of co-factors to regulate gene transcription, promote cell proliferation and survival, and affect invariant natural killer T cell (iNKT) development. This study aims to investigate the effect of Med1 on T cell development and CD4 T cell differentiation in immune response. Mice with T cell-specific knockout of gene (Med1 CD4cre , KO) were constructed and verified. The percentage and number of CD4 and CD8 T cells in thymus, spleen, and lymph nodes of KO mice and control (Con) mice (Med1 CD4cre ) were detected by flow cytometry. After 8 days of infection with lymphocytic choriomeningitis virus (LCMV), the percentage and number of CD4 T cells or antigen-specific (GP66 ) CD4 T cells, the percentage and number of Th1 cells (Ly6c PSGL1 ) in CD4 T cells or antigen-specific CD4 T cells were examined in the spleen of mice. Moreover, the fluorescence intensity of T-bet in CD4 T cells or antigen-specific CD4 T cells was analyzed. Compared with the Con group, the percentage and number of CD4 T cells and CD8 T cells in the thymus, CD4 T cells in the spleen and lymph nodes of the KO group showed no significant differences (all >0.05), but the percentage and number of CD8 T cells in the spleen and lymph nodes of the KO group were diminished significantly (all 0.05), while in comparison with the Con group, the percentage and number of Th1 cells in CD4 T cells or antigen-specific CD4 T cells, and the expression of T-bet in CD4 T cells or antigen-specific CD4 T cells were significantly reduced in the spleen of the KO group (all