Effect of azithromycin on natural killer cell function

► Azithromycin (AZM) shows anti-inflammatory activity aside from its antimicrobial effect. ► We examined the effect of AZM on natural killer (NK) cell function. ► AZM suppress CD69 expression and K562 cytotoxicity of IL-15-activated NK cells. ► AZM also inhibit IFN-gamma and TNF-alpha production of NK-92 and IL-15 activated NK cells. ► We demonstrate a new immunomodulatory effect of AZM to down-regulate NK response.