Expression of natural cytotoxicity receptors and a2V-ATPase on peripheral blood NK cell subsets in women with recurrent spontaneous abortions and implantation failures

Natural cytotoxicity receptors (NCRs) are unique markers, which regulate NK cell cytotoxicity and cytokine production. a2V-ATPase is expressed on subsets of PBMC and regulates the extracellular environment, which facilitates NK cytotoxicity or cytokine secretion. In this study, we aim to investigate the expression of NCRs and a2V-ATPase in peripheral blood NK cells of women with recurrent spontaneous abortions (RSA) or implantation failures. Peripheral blood NK cells (CD56(dim) and CD56(bright) were analyzed for the expression of NCRs (NKp46, NKp44 and NKp30) and a2V-ATPase using 3-color flow cytometry in women with RSA (n=24), implantation failures (n=19) or normal healthy women (n=13). CD56(+)/NKp46(+) cells were markedly decreased (P < 0.05) and CD56(bright)/a2V-ATPase(+) cells were significantly increased (P < 0.05) in women with RSA as compared to those of normal controls. In women with RSA or implantation failures, expression of NKp46, NKp44, NKp30, and a2V-ATPase on CD56(bright) NK cells was significantly up-regulated as compared with those of CD56(dim) NK cells. The differential expression of NCRs and a2V-ATPase in NK cell subsets may suggest dysregulation of NK cytotoxicity and cytokine production in women with RSA and implantation failures.