Invariant NKT and NKT-like lymphocytes: two different T cell subsets that are differentially affected by ageing.
The expression on T lymphocytes of surface receptors that are characteristically expressed on NK cells has led to the definition of a T cell subset that has been termed Natural Killer T (NKT) cells. Thus NKT cells constitute a minor lymphocyte population that exhibits features of both T cells and NK cells. However, the term 'NKT cell' has been applied variably to cells that express a restricted T-cell receptor (TCR) that recognizes glycolipids (alpha-GalCer) presented by the MHC-like molecule CD1d and that express CD161, as well as populations of conventional CD8 T cells that show up-regulated expression of NK-cell markers. The CD1d restricted T cells have a semi-invariant TCR using the Valpha24Jalpha18 genes in humans (Valpha24Jalpha18 in mice) and are denominated invariant NKT (iNKT) cells. On the other hand mainstream T cells that express NK associated receptors (NKR) show a highly specialized effector memory phenotype and are frequently referred as NKT-like cells. These T lymphocyte subsets are differentially affected by ageing. Whereas human peripheral blood iNKT cells decrease with age, there is an increase in the percentage of peripheral blood NKT-like T lymphocytes.
Peralbo
Esther
E
Department of Immunology, Faculty of Medicine, Reina Sofia University Hospital, University of Córdoba, 14004 Cordoba, Spain.
Alonso
Corona
C
Solana
Rafael
R
D000375:Aging / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D018949:Antigens, CD1 / Q000378:metabolism; D055610:Antigens, CD1d; D006801:Humans; D007694:Killer Cells, Natural / Q000145:classification / Q000166:cytology / Q000276:immunology*; D051379:Mice; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000378:metabolism; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000145:classification / Q000166:cytology / Q000276:immunology*
D015703:Antigens, CD; D018949:Antigens, CD1; D055610:Antigens, CD1d; C526877:CD1D protein, human; D011948:Receptors, Antigen, T-Cell; D011971:Receptors, Immunologic