Decreased TNF-alpha synthesis by macrophages restricts cutaneous immunosurveillance by memory CD4(+) T cells during aging

Research output: Contribution to journalArticle

Authors

  • E Agius
  • KE Lacy
  • M Vukmanovic-Stejic
  • AL Jagger
  • AP Papageorgiou
  • S Hall
  • JR Reed
  • J Fuentes-Duculan
  • M Salmon
  • LS Taams
  • J Krueger
  • J Greenwood
  • N Klein
  • MHA Rustin
  • AN Akbar

Colleges, School and Institutes

Abstract

Immunity declines during aging, however the mechanisms involved in this decline are not known. In this study, we show that cutaneous delayed type hypersensitivity (DTH) responses to recall antigens are significantly decreased in older individuals. However, this is not related to CC chemokine receptor 4, cutaneous lymphocyte-associated antigen, or CD11a expression by CD4(+) T cells or their physical capacity for migration. Instead, there is defective activation of dermal blood vessels in older subject that results from decreased TNF-alpha secretion by macrophages. This prevents memory T cell entry into the skin after antigen challenge. However, isolated cutaneous macrophages from these subjects can be induced to secrete TNF-alpha after stimulation with Toll-like receptor (TLR) 1/2 or TLR 4 ligands in vitro, indicating that the defect is reversible. The decreased conditioning of tissue microenvironments by macrophage-derived cytokines may therefore lead to defective immunosurveillance by memory T cells. This may be a predisposing factor for the development of malignancy and infection in the skin during aging.

Details

Original languageEnglish
Pages (from-to)1929-1940
Number of pages12
JournalThe Journal of Experimental Medicine
Volume206
Issue number9
Publication statusPublished - 1 Aug 2009