Expression and function of CD226 with CD16 on NK subsets / 中国免疫学杂志

ABSTRACT

Objective:To investigate the expression and function of CD226 on NK s ubsets and its coexpression with other activation receptor and inhibition recept or on NK cells. Methods:The expression of CD226 on CD56 bright and CD56 dim NK subsets and coe xpress ion with CD16 and NKG2A in PBMC and MLC in the presence or absence of IL-2 or IL-15 were detected by double fluorescent staining and flow cytometry analysis. The level of IFN-? in the supernatants of PBMC culture and MLC treated with o r without IL-2 or IL-15 were evaluated by ELISA. 51Cr release assay w as employed to measure the specific lysis of NK cells killing target K562 cells. Results:CD226 was mainly expressed on CD56 dim NK subsets in PBMC. When s imulated by IL-2, CD226 expression was shifted to CD56 bright NK subsets, while IL-15 increased the subpopulation of NKG2A+CD226+double positive cell s. In MLC-generated NK cells, CD226 was mainly expressed on CD56 dim NK su bsets, and also shifted to CD56 bright NK subsets in the addition of IL-15 . Furt hermore, the percentage of CD16+CD226+和NKG2A+CD226+ subsets were increa sed when stimulated by IL-2 or IL-15. There was great increase in IFN-? lev el in the supernatants of PBMC culture in the presence of IL-2 or IL-15, but no difference in the supernatants of MLC treated with or without two cytokine s. Moreover, the cytotoxicity of NK cells in PBMC and MLC were greatly enhanced by IL-2 or IL-15. Conclusion:CD226 is mainly expressed on CD56 bright NK subsets in IL-2 or IL-1 5 activated NK cells, and is coexpressed with CD16 and NKG2A preferentiatly, whi ch maybe involve in the modulation of cytotoxicity of NK cells based on the balance of coexpressed activation and inhibition receptors. [