An Observational Study on the Relationship Between Expression of Co-inhibitory Molecules on Treg and miR-155-5p Expression in the Peripheral Blood of Patients With Sepsis

there is high mortality rate of sepsis, 36% in 90-days of sepsis in China, and there is no effective treatment. Immunosuppression mediated by sepsis is an important cause of death in patients. Treg cells are important immunomodulatory cell. Treg's over-differentiation is involved in the development of sepsis induced immunosuppression. In sepsis patients, the expression of PD-1、CTLA-4 and TIGIT on Treg cell surface increased, and Treg cells with high expression of co-inhibitory molecules showed stronger immunosuppressive characteristics. MiR-155-5p is an unencoded RNA transcript from a proto-oncogene B cell integration cluster. In sepsis, the expression of miR-155 increased in peripheral blood and correlated with the patient's prognosis. Recent studies have shown that miR-155-5p promotes co-inhibitory molecules expressed on T cells in LCMV infected animal models. However, the relationship between the expression of peripheral blood miR-155-5p in sepsis patients and the expression of co-inhibitory molecules on Treg cell surface is not clear.