Expression of interleukin-37 in human peripheral blood CD4+CD25+regulatory T cells

Li Weimin; Xu Shuai; Dong Ning; Zhu Xiaomei; Zhang Qinghong; Yao Yongming

doi:10.3969/j.issn.1672-8521.2014.01.001

Abstract：Objective:To investigate the expression of interleukin-37 (IL-37)in healthy human peripheral blood CD4+CD25+ regulatory T cells (Tregs).Methods:Magnetic Activated Cell Sorting (MACS)kit was used to seg-regate CD4+CD25+Tregs in human peripheral blood,and the purity of CD4+CD25+Tregs was determined by flow cytometry. Proliferation activity of CD4+CD25+Tregs was measured in expander group (1×105 CD4+CD25+Treg were cultured with 20μl Dynabeads? Human Treg expander),non-expander group,and blank control group(cells were cultured with 10%FCS-RPMI 1640).Meanwhile,the expression of IL-37 in CD4+CD25+Tregs was analyzed by laser scanning confocal microscope and Western blot,respectively. Results:The purity of CD4+CD25+Tregs was over 93% after being isolated twice by magnetic beads,and the activity of CD4+CD25+Tregs exceeded 98%. In comparison with non-expander and blank control groups,proliferation activity in expander group was signifi-cantly increased along with the prolongation of stimulation. However,the non-expander group and blank control goup showed no significant proliferation. With laser scanning confocal microscope and Western blot,it was identi-fied the expression of IL-37 in human CD4+CD25+ Tregs. Under the stimulation by expander,the expression of IL-37 in CD4+CD25+Tregs was markedly enhanced. In addition,expression of IL-37 was obvious in the cyto-plasm, and its density was found to be high near the cell membrane under laser scanning confocal microscopy.Conclusions:In healthy human peripheral blood,IL-37 can positively express in CD4+CD25+Tregs. With the stimulation by expander,the expression of IL-37 might further be enhanced in CD4+CD25+Tregs.