Increased number of circulating Leu 11+ (CD 16) large granular lymphocytes and decreased NK activity during human ageing.

摘要: The phenotype and functional activity of circulating T natural killer (NK) cells was investigated in a group selected normal elderly donors comparison with young individuals. Old subjects exhibit decline an impaired response to mitogens (Con A, PHA) associated relative increase reacting Leu 7 11a monoclonal antibodies, directed against large granular lymphocytes NK activity. rise observed the not concomitant cytolytic K 562 tumour cells, time course kinetics cytotoxic reaction similar that subjects. When greater than 95% pure population 11a+ from old individuals sorted by flow cytometry their examined, significant decrease cytotoxicity detected. target cell binding capacity effector morphologically evaluated at single level, did differ subjects, even though bound have higher lytic capacity. These data show occurs during human ageing, but suggest only subset is active order maintain young.