Programmed death-1 and programmed death ligand-1 expressions on peripheral blood T lymphocytes from patients with condyloma acuminatum and their significance

Abstract

Objective To measure the expressions of programmed death-1(PD-1)and programmed death ligand-1(PD-L1)on peripheral blood T lymphocytes of patients with condyloma acuminatum(CA), and to investigate their role in cellular immunity in these patients. Methods Peripheral blood samples were obtained from 30 patients with CA(CA group)and 20 healthy human controls(control group). Flow cytometry was conducted to detect the expressions of PD-1 and PD-L1 on the surfaces of peripheral blood CD4+ and CD8+ T lymphocytes, and to determine the counts of CD4+ and CD8+ T lymphocytes. Enzyme-linked immunosorbent assay(ELISA)was performed to measure the levels of serum interleukin-2(IL-2)and interferon-γ(IFN-γ). Statistical analyses were carried out to compare the above parameters between the two groups, and to assess the relationship of PD-1 and PD-L1 expressions with the counts of CD4+ and CD8+ T lymphocytes as well as with the serum levels of IL-2 and IFN-γ. Results There was a significant increase in the expression rates of PD-1 and PD-L1 on CD4+ T lymphocytes(PD-1: 9.48% ± 3.31% vs. 7.12% ± 2.16%, t = 2.81, P 0.05). The levels of serum IL-2 and IFN-γ were both lower in the CA group than in the control group(t = 2.12, 2.16, respectively, both P 0.05). Conclusion PD-1 was highly expressed on peripheral blood T lymphocytes from patients with CA, which may inhibit T lymphocyte-mediated immune response, decrease CD4+ T lymphocyte counts, the CD4/CD8 ratio as well as IL-2 and IFN-γ serum levels by interacting with its ligand PD-L1 and forming the PD-1/PD-L1 signaling pathway. Key words: Condylomata acuminata; T-lymphocytes; Programmed death-1; Programmed death ligand-1