title: Natural cytotoxic reactivity of human lymphocyte subpopulations.
abstract: The spontaneous cytotoxicity of human peripheral blood lymphocyte preparations from normal donors for K562 target cells was examined. Effector cells were separated into SRBC rosette forming cell (RFC) and non-rosette forming cell (non-RFC) fractions using optimal and suboptimal rosetting procedures. RFC and non-RFC fractions both had high cytotoxic activity irrespective of the rosetting procedure. Owing to the larger size of the RFC fraction, it contained a higher proportion of the total activity in the preparation. Nylon fibre column adherent and non-adherent fractions also both produced cytotoxicity. Nylon fibre non-adherent cells separated by SRBC separation gave a RFC fraction with low activity and a non-RFC fraction with high activity. Separation of nylon fibre adherent cells gave RFC and non-RFC fractions with high cytotoxic activity. Therefore cytotoxic cells did not form a discrete subpopulation and either occur in several lymphocyte subsets or show a variable capacity to form SRBC rosettes and adhere to nylon fibre.
mesh_terms: D002448:Cell Adhesion; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007951:Leukemia, Myeloid / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*; D012397:Rosette Formation