The Significant Of PD-1/PD-L1 Expressed On Th17,Treg And CD8~+T Cells In HBV-related Liver Injury Patients

Objective: To discuss the correlations between different immune cells and signal pathway, by detected PD-1/PD-L1 expressed on Th17(T helper cell 17, Th17) 、Treg(regulator T cell,Treg) and CD8~+T cells in different types and clinical stages of HBV(hepatitis B virus,HBV) infected patients’ peripheral blood. Methods: Take three different types of HBV infected patients and normal controls as objects of study, ten cases AHB(acute hepatitis B) patients, than divided into three clinical stages: acute phase, convalescent phase, resolved phase; 20 cases CHB(chronic hepatitis B) patients: divided into 0 month, 1 month; 10 cases AsC(asymptomatic HBsAg carriers); 10 cases NC(normal control). PD-1/PD-L1(programmed cell death-1/programmed cell death 1 ligand,PD-1/PD-L1) expressed on Th17、Treg and CD8~+T of different clinical stages of above all patients were assessed by flow cytometric analysis, observe the relationship between PD-1/PD-L1 expressed on Th17 cells and disease; the correlations between PD-1 expressed on Th17 and PD-L1 expressed on Treg, PD-1 expressed on CD8~+T cells PD-L1 expressed on Treg. Results: 1.The expression of PD-1/PD-L1 on Th17 cells of different types of HBV infected patients: At the baseline of AHB(acute phase),CHB(0 month) and AsC patients’ peripheral blood, PD-1 expressed on Th17 cells and PD-L1 expressed on Th17 all higher than the normal control(all P<0.05). the PD-1 expressed on Th17 and PD-L1 expressed on Th17 of AsC patients are higher than AHB and CHB patients(all P < 0.05), the PD-1/PD-L1 expressed on Th17 between AHB and CHB are no significant difference(all P>0.05). 2. The dynamic change of PD-1/PD-L1 expressed on Th17 cells of AHB patients and the correlation with alanine transaminase(ALT): The expression of PD-1/PD-L1 on Th17 cells in convalescent phase increased significantly, compared with acute phase(all P<0.05); the expression of PD-1/PD-L1 on Th17 cells are increased slightly in resolved phase, compared with convalescent phase(all P > 0.05), no correlation was found between PD-1/PD-L1 expressed on Th17 and ALT(all P>0.05). 3. The dynamic change of PD-1/PD-L1 expressed on Th17 cells of CHB patients and the correlation with ALT, HBV DNA: Compared with 0 month, PD-1 and PD-L1 expressed on Th17 in 1 month of CHB patients increased significantly(all P<0.05);No correlations were found between PD-1/PD-L1 expressed on Th17 and ALT(r =0.35; r =0.39,all P>0.05), HBV DNA(r =-0.186; r=0.2, all P>0.05)of CHB patients at 0 month. 4. The correlations between PD-1 expressed on Th17 and PD-L1 expressed on Treg, PD-1 expressed on CD8~+T cells and PD-L1 expressed on Treg of HBV infected patients: PD-1 expressed on CD8~+T are all positively correlated with PD-L1 expressed on Treg of AHB and CHB patients at baseline(r=0.647, r=0.407, all P<0.05). no correlation was found between PD-1 expressed on CD8~+T and PD-L1 expressed on Treg of AsC(r =0.271, P>0.05).no correlation was found between PD-1 expressed on Th17 and PD-L1 expressed on Treg of AHB, CHB and AsC patients(r =-0.026;r =-0.24;r =0.079,all P>0.05). Conclusion:(1). PD-1/PD-L1 expressed on Th17 cell in HBV infected immune response may mainly related to hepatocyte immune injury, and have no related with virus clearance.(2). In multiple anti-HBV related immune responses, there is a positive correlation between PD-1 expressed on CD8~+T and PD-L1 expressed on Treg. Which suggested there may be ligand-receptor relationship.