title: Age-associated changes in interferon-gamma and interleukin-4 secretion by purified human CD4+ and CD8+ T cells.
abstract: Aging is associated with a decline in immune function. Interferon-gamma (IFN-gamma) and interleukin-4 (IL-4), two important immune deviation-related cytokines, are mainly produced by type 1 and type 2 T cells, respectively. To investigate the age-associated changes in the secretion of these two cytokines, 20 elderly and 20 young subjects fulfilling the SENIEUR protocol were enrolled. The ratios of CD4+ to CD8+ T cells were not different between the two age groups. The CD4+ and CD8+ T cells were purified by a magnetic cell sorting system, and then activated by concurrent anti-CD3 and anti-CD28 stimulation. The released cytokines were determined by ELISA. Both the CD4+ and the CD8+ T cells of the elderly individuals secreted a significantly larger amount of IFN-gamma after activation. Profound IL-4 production by CD8+ T cells was observed in the older subjects compared with that of the young subjects. These data suggested that age-associated decrease in immunity may be related to an imbalance in the secretion of immune deviation cytokines. The number of IL-4-secreting CD8+ T cells (T cytotoxic 2) rose significantly in the older individuals. Our design also provided a useful way to differentiate the T cell subsets secreting the same cytokine, such as IFN-gamma-producing T helper 1 and T cytotoxic 1 cells.
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan, ROC.
authors.forename: C J
authors.initials: CJ
authors.lastname: Yen
authors.forename: S L
authors.initials: SL
authors.lastname: Lin
authors.forename: K T
authors.initials: KT
authors.lastname: Huang
authors.forename: R H
authors.initials: RH
authors.lastname: Lin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000276:immunology*; D016516:CD4-CD8 Ratio; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis / Q000378:metabolism*; D015847:Interleukin-4 / Q000096:biosynthesis / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male
chemical_list: D015847:Interleukin-4; D007371:Interferon-gamma