Quantitative assessment of lymphocyte surface antigen expression patterns affecting NK cell activity in healthy individuals

Abstract

Purpose: The number and proportion of natural killer (NK) cells has not been shown to directly correlate with NK cell activity. It has been suggested that the expression patterns of NK cell surface antigens may influence their activity, but there is no quantitative assessment of cell surface antigen expression patterns in healthy individuals. The purpose of this study was to identify expression patterns of NK cell surface antigens that correlate with NK cell activity and to quantitatively assess the correlation between antigen expression patterns and NK cell activity.

Methods: NK cell cytotoxicity assays and two-color flow cytometry were performed on peripheral blood lymphocytes from 18 healthy individuals. The correlation between coexpression patterns of NK cell surface antigens (CD16/CD56, CD16/CD57) and NK cell cytotoxicity was quantitatively evaluated.

Results: Pearson's correlation coefficients for CD16+CD56+ and CD16+CD57+ were 0.78 and 0.68, while CD16-CD56- and CD16-CD57- were -0.63 and -0.49, respectively. NK cell activity was positively correlated with CD16+CD56+ (p < 0.001) and CD16+CD57+ (p = 0.002) expression, but negatively correlated with CD16-CD56- (p = 0.005) and CD16-CD57- (p = 0.040) expression.

Conclusions: Both CD16/CD56 and CD16/CD57 expressions influenced NK cell activity, but coexpression patterns of CD16/CD56 tended to be more sensitive than those of CD16/CD57 for predicting NK cell activity.