Increased cytokine production in mononuclear cells of healthy elderly people

TLDR

Cytokine production during aging, except IL‑2, has been largely overlooked in humans. The study measured in vitro production of IL‑6, TNF‑α, IFN‑γ, and IL‑1β by peripheral mononuclear cells from healthy young and aged adults. Stimulation of mononuclear cells from healthy elderly individuals led to significant increases in IL‑6, TNF‑α, and IL‑1β production, while IFN‑γ levels and cell proliferation remained unchanged, indicating preserved cytokine machinery that may contribute to age‑related inflammatory conditions such as atherosclerosis, osteoporosis, fibrosis, and dementia.

Abstract

Abstract The production of cytokines during aging, except interleukin (IL)‐2, has been neglected in humans. We measured the in vitro production of IL‐6, tumor necrosis factor (TNF)‐α, interferon (IFN)‐γ and IL‐1β by peripheral mononuclear cells from selected healthy young (mean age 26.8 years) and aged (mean age 80.2 years) subjects. Significant increases of IL‐6, TNF‐α and IL‐1bT levels were found in mitogen‐stimulated cultures from aged donors, occurring at 24 to 72 h after stimulation. No significant differences were observed for IFN‐γ production. Proliferative capability of cells stimulated with PHA was not impaired in aged subjects. Since the amounts of all cytokines studied were similar in unstimulated cultures from young and aged subjects, and also serum levels of TNF‐a did not differ, these data indicate that the cellular machinery for the production of these cytokines is well preserved in aging, and also that cells from old people are able to up‐regulate their production in response to appropriate stimuli. The increases in cytokine synthesis were not dependent on changes in the number of monocytes, nor were they related to the significant rise of CD45RO + , and the concomitant decrease of CD45RA + occurring in both CD4 + and CD8 + lymphocytes from aged subjects. The increased production of pro‐inflammatory cytokines by stimulated mononuclear cells of healthy aged subjects may be relevant to several aspects of age‐associated pathological events, including atherosclerosis, osteoporosis, fibrosis and dementia.