NATURAL KILLER CELL ACTIVITY AND ANTIBODY‐DEPENDENT CELLULAR CYTOTOXICITY IN NEWBORN INFANTS

Abstract

The ability of lymphocytes from the peripheral blood of preterm and term infants and adult women and men to mediate natural killing (NK) and K cell activity (antibody-dependent cellular cytotoxicity) was analyzed in 4 h 51Cr-release assays. K 562 cells were targets for NK activity. K cell activity was assayed on antibody-coated rat thymocytes. Lymphocytes from adult male donors were significantly more cytotoxic to K 562 cells than were lymphocytes from adult female donors. Lymphocytes from both preterm and term infants had significantly lower NK and K cell activity than lymphocytes from adult donors. During the 1st month of life no increase in NK activity or K cell activity occurred in 7 infants who were re-examined. Apparently, neither NK nor K cell activities are fully developed during the 1st month of life.