[Natural killer lymphocytes. Their role in pathology].
Natural killer lymphocytes can spontaneously kill in vitro a variety of malignant cultured cells. NK cells are present in all normal individuals, and in some species (human, rats) present peculiar morphological features (large granular lymphocytes). They are usually lacking conventional T or B markers, but it appears likely that most NK cells actually are poorly mature cells belonging to the T cell lineage. The physiological control of NK activity is complex. A major role seems to be devoted to the production of interferon. The physiological roles of NK cells are still unknown: they might participate in the control of cell differentiation, in peculiar of hematopoietic precursors and thymocytes; they probably play a role as defense mechanisms during the first days of viral infections; they might be involved in bone-marrow allograft rejection and in acute graft-versus-host disease. However, their actual role in anti-tumor surveillance remains controversial, especially in humans. Nevertheless, NK cells might play some role in the surveillance against leukemias and lymphomas. NK cell defects could participate in the increased occurrence of lymphoproliferative disorders observed in immuno-suppressed patients.
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D000818:Animals; D016026:Bone Marrow Transplantation; D006086:Graft vs Host Disease / Q000276:immunology; D006801:Humans; D007157:Immunologic Surveillance; D007165:Immunosuppression Therapy / Q000009:adverse effects; D007694:Killer Cells, Natural / Q000502:physiology*; D008232:Lymphoproliferative Disorders / Q000276:immunology; D051379:Mice; D009369:Neoplasms / Q000276:immunology; D012306:Risk; D014181:Transplantation Immunology; D014777:Virus Diseases / Q000276:immunology
Les lymphocytes tueurs naturels. Leur rôle en pathologie.