The expression and correlation analysis of TOX and inhibitory receptors on peripheral blood CD8+T cells in patients with aplastic anemia

Abstract

Objective: To investigate the expression levels of thymocyte selection related high mobility group proteins (TOX) and different inhibitory receptors in peripheral blood CD8+T cells of patients with aplastic anemia (AA), and to conduct correlation analysis. Methods: From September 2019 to November 2020, 27 AA patients in the Department of Hematology, General Hospital of Tianjin Medical University were retrospectively selected, including 21 males and 6 females, with a median age [M (Q1, Q3)] of 48 (30, 72) years. Thirty-three healthy controls, included 17 males and 16 females, with a median age of 46 (27, 69) years. The expression levels of TOX, programmed cell death receptor-1 (PD-1), T-cell immunoglobulin and mucin domain 3 (TIM-3), cytotoxic T-lymphocyte associated antigen-4 (CTLA-4), T-cell immune receptor with immunoglobulin (Ig) and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT), perforin and granzyme B in peripheral blood CD8+T cells from AA patients and healthy controls were detected by flow cytometry. The correlation between TOX expression levels and different inhibitory receptors was analyzed using Pearson correlation analysis. Results: The expression levels of TOX, PD-1, TIM-3, CTLA-4, TIGIT, perforin, and granzyme B in peripheral blood CD8+T cells of AA patients were 47.33%(41.47%, 56.61%), (30.61±12.37)%, (39.94±10.84)%, (6.21±3.40)%, (51.45±20.21)%, (71.32±22.46)%, and (52.39±23.99)%, respectively, which were higher than those of healthy controls 27.32%(21.64%, 46.96%), (21.29±10.01)%, (21.11±3.00)%, (1.31±0.34)% (30.80±13.40)%, (46.72±22.53)%, (21.75±16.43)% (all P<0.05). The expression level of TOX in CD8+T cells was positively correlated with the expression levels of PD-1, TIM-3, CTLA-4, TIGIT, perforin, and granzyme B (r=0.49, 0.65, 0.70, 0.54, 0.58, 0.48, all P<0.05). Conclusion: The expression levels of TOX and different inhibitory receptors on peripheral blood CD8+T cells in AA patients are higher than those in the healthy control group, and the expression levels of TOX and different inhibitory receptors are positively correlated.