Variation of human natural killer cell phenotypes with age: Identification of a unique KLRG1-negative subset

• Published in: Human immunology 2010-07, Vol.71 (7), p.676-681
• Main Authors: Hayhoe, Richard P.G, Henson, Sian M, Akbar, Arne N, Palmer, Donald B
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Aging; Aging - immunology; Allergy and Immunology; Antigens, CD - metabolism; Antigens, Differentiation, T-Lymphocyte - metabolism; CD3 Complex - metabolism; CD56 Antigen - metabolism; Cell Count; Humans; Immunophenotyping; Immunosenescence; Interferon-gamma - metabolism; Interleukin-15 - pharmacology; Killer Cells, Natural - cytology; Killer Cells, Natural - drug effects; Killer Cells, Natural - metabolism; Lectins, C-Type - metabolism; Leukocytes, Mononuclear - cytology; Leukocytes, Mononuclear - drug effects; Lymphocyte Subsets - cytology; Lymphocyte Subsets - drug effects; Lymphocyte Subsets - metabolism; Lysosomal-Associated Membrane Protein 1 - metabolism; Middle Aged; Natural killer cells; Trans-Activators - metabolism; Young Adult
• ISSN: 0198-8859; 1879-1166
• DOI: 10.1016/j.humimm.2010.03.014

Abstract Human natural killer (NK) cells subsets are phenotypically characterized by their lack of CD3 and low/high expression of CD56. This study revealed an age-associated increase in the ratio of CD3− CD56dim to CD3− CD56bright NK cells, whereas distinct expression patterns of CD2, CD16, CD57, and the C-type lectin family members killer cell lectin–like receptor −D1 (CD94) and −G1 (KLRG1), were noted on both these NK and the CD3+ CD56+ T cell subsets; moreover, CD94 and KLRG1 expression were significantly reduced with age. Although the proportion of CD3− CD56bright NK cells vs CD3− CD56dim cells decreased with age, the percentage of CD3− CD56bright cells expressing IFN-γ after activation significantly increased, potentially representing compensatory augmentation of cytokine production to maintain the important immunoregulatory role of these cells in older individuals. Collectively, these results highlight new evidence for a continuum of change during immunologic aging and present unique data for variation of NK cell subsets with human aging.