%0 Journal Article
%T Aging related changes of circadian rhythmicity of cytotoxic lymphocyte subpopulations
%A Gianluigi Mazzoccoli
%A Angelo De Cata
%A Antonio Greco
%A Marcello Damato
%A Nunzia Marzulli
%A Mariangela Dagostino
%A Stefano Carughi
%A Federico Perfetto
%A Roberto Tarquini
%J Journal of Circadian Rhythms
%D 2010
%I BioMed Central
%R 10.1186/1740-3391-8-6
%X Lymphocyte subpopulation analyses were performed and cortisol serum levels were measured on blood samples collected every four hours for 24 hours from fifteen healthy male young-middle aged subjects (age range 36-55 years) and fifteen healthy male old aged subjects (age range 67-79 years).In healthy young-middle aged subjects CD20 were higher and at 06:00 h CD8+ dim correlated positively with CD16+ and positively with ¦Ã¦ÄTCR+ cells, CD16 correlated positively with ¦Ã¦ÄTCR+ cells At 18:00 h CD8+ dim correlated positively with CD16+ and positively with ¦Ã¦ÄTCR+ cells, CD16+ correlated positively with ¦Ã¦ÄTCR+ cells and a clear circadian rhythm was validated for the time-qualified changes of CD3+, CD4+, CD20+, CD25+ and HLA-DR+ cells with acrophase during the night and for the time-qualified changes of CD8+, CD8+ bright, CD8+ dim, CD16+ and ¦Ã¦ÄTCR+ cells with acrophase during the day. In old aged subjects CD25, DR+ T cells and cortisol serum levels were higher, but there was no statistically significant correlation among lymphocyte subpopulations and a clear circadian rhythm was evidenced for time-qualified changes of CD3+ and CD25+ cells with acrophase during the night and for the time-qualified changes of CD8+ cells and cortisol with acrophase during the day.Our study has evidenced aging-related changes of correlation and circadian rhythmicity of variation of cytotoxic lymphocyte subpopulations that might play a role in the alteration of immune system function in the elderly.There are a number of reports in the scientific literature that put in evidence a circadian rhythm of variation of total lymphocytes in the peripheral blood, of antibodies and cell mediated immune responses [1,2] and an inverse relationship with plasma cortisol concentration [3]. Alteration of circadian rhythmicity has been evidenced in the elderly. A small fraction of peripheral T cells coexpress CD4 and low levels of CD8 (CD4+CD8dim) and can have cytotoxic activity. NK receptors are constitutively expr
%U http://www.jcircadianrhythms.com/content/8/1/6