The role of monocytes Siglec-1 in stimulating CD4 + and CD8 + T cells proliferation and activation in atherosclerosis / 中华检验医学杂志

ABSTRACT

Objective To investigate the role of atherosclerotic monocytes Siglec-1 in stimulating CD4 + and CD8 + T lymphocytes proliferation and activation.Methods Experimental research.Cluster of differentiation antigen 14 (CD14) positive monocytes of 18 acute coronary syndrome (ACS),41 stable angina (SA) and 32 healthy volunteers were separated by magnetic-activated cell sorting.Different concentration of interferon-α (IFN-α,0,2,5,10 ng/ml) were used to up-regulate Siglec-1 and small interfering RNA (siRNA) or blocking antibody were used to down-regulate Siglec-1.Then monocytes were cocultured with CD4 + T/CD8 + T cells from a third healthy volunteer for 5 days.The experiment was designed for 11 groups (n=10 for each group),that was (1) normal CD14,(2) normal CD14 + IFN-α 5 ng/ml,(3) normal CD14 + IFN-α 5 ng/ml + anti-Siglec-1 2 μg/ml,(4) ACS CD14,(5) ACS CD14 + control siRNA group (Mock),(6) ACS CD14 + siRNA 679 40 nmol/L,(7) ACS CD14 + anti-Siglec-1 2 μg/ml,(8) SA CD14,(9) SA CD14 + Mock,(10) SA CD14 + siRNA 679 40 nmol/L and (11) SA CD14 + antiSiglec-1 2 μg/ml.Cell Counting Kit-8 (CCK-8) was used to determine T cells proliferation and ELISA was used to detect Interleukin-2 (IL-2),IL-10,IL-12 and IFN-γ of culture supematant.Data of cytokines detection were expressed as medium (quartiles) and analyzed by nonparametric rank sum test.Results By the blockage of Siglec-1 (group 6),the proliferation of CD4 and CD8 were decreased.Secretion of IL-2,IL-12 and IFN-γ by CD4 cells [67.00(62.50-87.30),0.86(0-1.63),and 47.82(37.60-56.67) pg/ml,respectively] were decreased and IL-10 [56.00(46.25-67.40) pg/ml] was increased compared with those in control group [group 4,213.70 (187.50-275.30),6.87 (4.90-8.93),114.90 (89.50-167.40),and 21.08 (15.70-33.20) pg/ml,respectively,with U =8.50,17.00,8.50,and 87.50,respectively.all P ＜ 0.05].When monocytes Siglec-1 from control group was up-regulated by IFN-α (group 2),secretion of IL-2,IL-12 and IFN-γ [220.44(174.30-312.30),7.90(6.540-10.40) and 143.75(78.20-210.00) pg/ml,respectively] were increased and IL-10 [21.95 (16.30-25.00) pg/ml] was decreased (compared with group 1,with U =89.50,98.00,100.00,and 0,respectively.all P ＜ 0.05).Regulation of Siglec-1 had no role in cytokines production in cocultured CD8 + T cells (all P ＞ 0.05).Conclusions IFN-α can upregulate monocytes Siglec-1.Siglec-1 may participate in the pathogenesis of AS via promoting proliferation of CD4 +/CD8 + T cells and Thl cytokines secretion of CD4 + T cells.