The Frequency And Clinical Significance Of CD8⁺CD28^-and CD4⁺CD25^highRegulatory T Cells During The Progression Of HBV Infection

[AIM]Accumulating evidence demonstrates thatCD8+CD28-regulatory T cells increase in chronic viral infection as well as tumorigenesis.However,it is still not clear about their characteristics in hepatitis B virus(HBV)infection.Additionally,it is not understood whether this regulatory immune subset is distinct from CD4+CD25high regulatory T cells in the aspect of impact on or relation to the progression of HBV infection.Hence,this study aims to investigate their dynamics and compared their correlations with clinical parameters in the chronic and advanced phases of HBV infection.[METHODS]The frequency of circulating CD8+CD28-and CD4+CD25high regulatory T cells was determined by flow cytometry.The serological markers of HBV infected patients were measured using the Enzyme-linked immunosorbent assay Kits.HBV viral load was determined with HBV LC PCR Kit.ALT and AST,which indicate the liver function,were analyzed by using Roche Automatic Biochemistry Analysis Meter.[RESULTS]The results showed that compared with healthy controls(HC),the frequencies of CD8+CD28-and CD4+CD25high T cells increased in both chronic and advanced phases,while there is no significant difference between the two case groups.Interestingly,we found that in chronic phase,the frequency of CD8+CD28-subset was negatively correlated with the levels of alanine aminotransaminase(ALT)and aspartate aminotransferase respectively and did not present association with HBV DNA load,whereas that of T cells was positively correlated with HBV DNA load and the levels of ALT and AST respectively.Amazingly,in advanced phase,the frequency of CD4+CD25high T cells was negatively correlated with HBV DNA load and the levels of ALT respectively,while there is no significant correlation between the frequency of CD8+CD28-subset and those clinical parameters.[CONCLUSION]This research demonstrated that CD8+CD28 and CD4+CD25high regulatory T cells might exert distinct effect on modulating antiviral immune responses and mitigate immunomediated liver damage in different phases of HBV infection,which represent potential prognostic markers and therapeutic targets for HBV infected patients based on futher exploration of detailed mechanism.