Influence of menstrual cycle on NK activity

• Published in: Journal of reproductive immunology Vol. 50; no. 2; pp. 151 - 159
• Main Authors: Souza, S.S, Castro, F.A, Mendonça, H.C, Palma, P.V.B, Morais, F.R, Ferriani, R.A, Voltarelli, J.C
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01.05.2001; Elsevier Science
• Subjects: Adult; Aged; Biological and medical sciences; CD16 antigen; CD3 antigen; CD56 antigen; Cytotoxicity, Immunologic; Female; Flow cytometry; Follicular Phase - immunology; Fundamental and applied biological sciences. Psychology; Hormone metabolism and regulation; Humans; In Vitro Techniques; K562 Cells; Killer Cells, Natural - immunology; Luteal Phase - blood; Luteal Phase - immunology; Male; Mammalian female genital system; Menopause - immunology; Menstrual cycle; Menstrual Cycle - immunology; Middle Aged; Natural killer; Progesterone; Progesterone - blood; Sex Characteristics; Vertebrates: reproduction; Flow cytometry; Progesterone; Menstrual cycle; Natural killer; Natural killer cell; Human; Luteal phase; Female; Sex steroid hormone; Ovarian hormone; Follicular phase
• ISSN: 0165-0378; 1872-7603
• DOI: 10.1016/S0165-0378(00)00091-7

Natural killer (NK) cells are CD3 − CD56 + and/or CD16 + cytotoxic lymphocytes that mediate first-line defense against various types of target cells without prior immunization. To assess the effect of the menstrual cycle and gender on NK activity we evaluated 30 healthy women (mean age 28.1 years, range 21–39) in follicular and luteal phases, 29 postmenopausal women (mean age 58.8 years, range 42–72) and 48 healthy men (mean age 31.6 years, range 21–40). In a flow cytometric test of NK activity, peripheral blood mononuclear effector cells were mixed with K562 targets cells labeled with DiO (3,3′-dioctadecyloxacarbocyanine perchlorate) at effector:target cell ratios of 40, 20, 10 and 5:1. Dead cells were stained with propidium iodide and results were expressed as lytic units per 10 7 cells. In addition, progesterone levels were determined in the luteal phase of the menstrual cycle of healthy women by a chemiluminescence assay. Our results showed that (1) NK cytotoxicity was higher in the follicular than in the luteal phase of the menstrual cycle ( P<0.0001); (2) postmenopausal women and men showed NK activity similar to women in the folicular phase but higher than women in the luteal phase of the menstrual cycle ( P<0.05); and (3) there was no correlation between NK activity and levels of progesterone. The data suggest that progesterone does not influence NK activity directly and that other factors may explain the reduction of NK activity in the luteal phase of the menstrual cycle.