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Decreased programmed death-1 expression on the T cells of patients with ankylosing spondylitis.
Zhou, L, Zhang, Y, Xu, H, Hu, L, Zhang, C, Sun, L, Xie, Y, Lu, H, Zhang, Z, Hu, W, et al
The American journal of the medical sciences. 2015;(6):488-92
Abstract
BACKGROUND Programmed death-1 (PD-1) plays a vital role in down-modulating immune responses and maintaining peripheral tolerance. METHODS The authors have investigated the inducible expression of PD-1 on activated T cells from patients with ankylosing spondylitis (AS). Thirty patients with AS and 31 unrelated healthy controls (HCs) were recruited in this study. The expression of PD-1 on T cells harvested from nonstimulated (t0) or stimulated cultures with phytohemagglutinin for 24 hours (t24) was determined by flow cytometry. The multiple levels of the PD-1 expression on stimulated and nonstimulated cells from each individual's sample (t24/t0) represented as the degree of the inducible effect on PD-1 expression. RESULTS The expression of PD-1 on nonstimulated T cells presented no significant difference between AS group and HC group (P > 0.05). After stimulation, the degree of effect on PD-1 expression of CD4+, CD4+CD25+, CD4+CD25 high, CD4+CD25 low and CD4+CD25- T cells were significantly lower in patients with AS than those in HC group (1.9 ± 0.9 versus 3.6 ± 2.3, 9.7 ± 7.4 versus 17.8 ± 12.6, 87.8 ± 48.6 versus 157.3 ± 117.0, 3.7 ± 1.4 versus 7.3 ± 2.4, 0.5 ± 0.3 versus 1.1 ± 0.6, respectively, P < 0.05). However, there was no significant difference of the effect on all lymphocytes and CD8+ T cells between patients with AS and HCs (P > 0.05). CONCLUSIONS The decreased inducible expression of PD-1 on active T lymphocytes, especially on CD4+CD25 high and CD4+CD25+ T cells, may be one of important factors involved in the development of AS.