RESUMO
Human natural killer (NK) cells comprise 2 main subsets, CD56(bright) and CD56(dim) cells, that differ in function, phenotype, and tissue localization. To further dissect the heterogeneity of CD56(dim) cells, we have performed transcriptome analysis and functional ex vivo characterization of human NK-cell subsets according to the expression of markers related to differentiation, migration or competence. Here, we show for the first time that the ability to respond to cytokines or to activating receptors is mutually exclusive in almost all NK cells with the exception of CD56(dim) CD62L(+) cells. Indeed, only these cells combine the ability to produce interferon-gamma after cytokines and proliferate in vivo during viral infection with the capacity to kill and produce cytokines upon engagement of activating receptors. Therefore, CD56(dim) CD62L(+) cells represent a unique subset of polyfunctional NK cells. Ex vivo analysis of their function, phenotype, telomere length, frequencies during ageing as well as transfer experiments of NK-cell subsets into immunodeficient mice suggest that CD56(dim) CD62L(+) cells represent an intermediate stage of NK-cell maturation, which after restimulation can accomplish multiple tasks and further develop into terminally differentiated effectors.
Assuntos
Antígeno CD56/metabolismo , Células Matadoras Naturais/metabolismo , Selectina L/metabolismo , Leucócitos Mononucleares/metabolismo , Subpopulações de Linfócitos/imunologia , Animais , Biomarcadores/metabolismo , Western Blotting , Proliferação de Células , Células Cultivadas , Citocinas/metabolismo , Citotoxicidade Imunológica/imunologia , Citometria de Fluxo , Perfilação da Expressão Gênica , Humanos , Interferon gama/metabolismo , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/transplante , Ativação Linfocitária , Subpopulações de Linfócitos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Camundongos SCID , Análise de Sequência com Séries de Oligonucleotídeos , Receptores de Quimiocinas/metabolismo , Telômero/fisiologia , Irradiação Corporal TotalRESUMO
The basic helix-loop-helix transcriptional repressor twist1, as an antagonist of nuclear factor kappaB (NF-kappaB)-dependent cytokine expression, is involved in the regulation of inflammation-induced immunopathology. We show that twist1 is expressed by activated T helper (Th) 1 effector memory (EM) cells. Induction of twist1 in Th cells depended on NF-kappaB, nuclear factor of activated T cells (NFAT), and interleukin (IL)-12 signaling via signal transducer and activator of transcription (STAT) 4. Expression of twist1 was transient after T cell receptor engagement, and increased upon repeated stimulation of Th1 cells. Imprinting for enhanced twist1 expression was characteristic of repeatedly restimulated EM Th cells, and thus of the pathogenic memory Th cells characteristic of chronic inflammation. Th lymphocytes from the inflamed joint or gut tissue of patients with rheumatic diseases, Crohn's disease or ulcerative colitis expressed high levels of twist1. Expression of twist1 in Th1 lymphocytes limited the expression of the cytokines interferon-gamma, IL-2, and tumor necrosis factor-alpha, and ameliorated Th1-mediated immunopathology in delayed-type hypersensitivity and antigen-induced arthritis.