Expressions of programmed death-1 and programmed death ligand on the surface of peripheral blood lymphocytes in patients with tuberculosis / 中华传染病杂志

ABSTRACT

Objective To describe the expressions of programmed death-1 (PD-1) and its ligand PD-L1 on the surface of peripheral blood lymphocytes in patients with tuberculosis.Methods A total of 77 cases of pulmonary tuberculosis were recruited,of which 27 were single infection,41 were coincident with bacterial or fungal infection and 9 patients with diabetes mellitus.Twenty-nine healthy donors were also enrolled as control group.The expressions of PD-1/PD-L1 on the peripheral blood lymphocytes and mononuclear cells were detected using immunostaining and flow cytometry.Collected data were analyzed with t-test statistics.Results Among the three groups of tuberculosis including pulmonary tuberculosis,pulmonary tuberculosis coincident with infection and pulmonary tuberculosis with diabetes mellitus,the percentages of CD4+ CD25+ T cells as well as CD4+ CD25high T cell subsets were both significantly higher than those in healthy controls (t=4.892,4.635,4.974,5.407,4.660,5.279,all P＜0.01).The expression of PD-1 was up regulated on the surface of CD8+ T cells in the groups of tuberculosis as compared with the control group (t=6.392,8.249,7.072,all P＜0.01).The proportions of PD-L1 expressed on the monocytes in each group were (42.51 ± 7.54) ％,(49.42± 6.29) ％ and (48.46 ± 14.58)％,respectively.The difference was significant in contrast to the control group,which was (17.91 ±3.03)％ (t=5.168,6.854,5.665,all P＜0.01).PD-L1 expression was also up-regulated on B cells in each group and much higher than that of the control group (51.51±7.32)％,(50.85±7.09)％,(55.66±14.29)％ vs (40.11±4.25)％ (t=2.562,2.046,2.766,all P＜0.05).Conclusion PD-1/ PD-L1 co-inhibitory pathway could be closely related to the development of tuberculosis and its complications,which is involved in the attenuation of anti-tuberculosis and anti infection immune responses.