The modulatory activity of T cell immunoglobulin and mucin domain-containing protein 3 on T lymphocytes in patients with chronic heart failure

Abstract

Objective: To investigate the expression of T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) in patients with chronic heart failure and its modulatory activity on T lymphocytes. Methods: Eighty-six patients with chronic heart failure (CHF group) who were hospitalized in Department of Cardiology, the First Affiliated Hospital of Zhengzhou University between January and October 2018 were enrolled in the study. Meanwhile, thirty-two healthy controls (HC group) who received healthy examination were also selected. Peripheral blood mononuclear cells were isolated, and TIM-3 expression of CD4(+)and CD8(+)T cells was investigated by flow cytometry. CD4(+)and CD8(+)T cells were purified, and were stimulated by anti-TIM-3 antibody. Interferon-γ (IFN-γ), interleukin (IL)-4, IL-10, IL-35, IL-17, and IL-22 expressions in the supernatants of cultured CD4(+)T cells and tumor necrosis factor-α (TNF-α) and IFN-γ expressions in the supernatants of cultured CD8(+) T cells were measured by enzyme-linked immunosorbent assay. mRNA expressions of T-bet, GATA-3, FoxP3, and RORγt in CD4(+)T cells and perforin and granzyme B in CD8(+)T cells were semi-quantified by real-time PCR. Student t test or paired t test was used for comparisons between the two groups. Results: TIM-3(+) CD4(+) T cell percentage significantly increased in CHF group than that of HC group (3.47%±1.06% vs 0.92%±0.27%, P<0.001). TIM-3(+)CD8(+)T cell percentage also notably elevated in CHF group compared to HC group (6.12%±1.91% vs 1.77%±0.63%, P<0.001). CD4(+)T and CD8(+)T cells were dysfunctional in chronic heart failure. The levels of IFN-γ, IL-17, and IL-22 secreted by purified CD4(+) T cells significantly reduced in CHF group, while IL-10 and IL-35 expressions elevated in CHF group (all P<0.05). The relative mRNA expression levels of T-bet and RORγt in CD4(+) T cells remarkably decreased in CHF group than those of HC group (all P<0.01), while relative expression level of FoxP3 mRNA increased in CHF group (1.93±0.88 vs 0.97±0.28, P=0.031). The levels of TNF-α and IFN-γ produced by purified CD8(+)T cells notably reduced in CHF group than those of HC group (all P<0.05), and relative mRNA expression levels of perforin and granzyme B also decreased in CHF group (all P<0.05). The levels of anti-TIM-3 antibody stimulation-produced IFN-γ, IL-17, and IL-22 increased (all P<0.05) but IL-35 secretion reduced [(61±13) ng/ml vs (72±17) ng/ml, P=0.029] by CD4(+)T cells in CHF group. The relative mRNA expression levels of T-bet and RORγt also elevated in response to anti-TIM-3 antibody stimulation (all P<0.05). Anti-TIM-3 antibody stimulation promoted TNF-α and IFN-γ production by CD8(+)T cells in CHF group (all P<0.01). The relative mRNA expression levels of perforin and granzyme B also increased (all P<0.05). Conclusion: TIM-3 was increasingly expressed in T cells from patients with chronic heart failure, and might take part in the regulation of T cell dysfunction in chronic heart failure.