Aging of the innate immune system.
The innate immune system is composed of a network of cells including neutrophils, NK and NKT cells, monocytes/macrophages, and dendritic cells that mediate the earliest interactions with pathogens. Age-associated defects are observed in the activation of all of these cell types, linked to compromised signal transduction pathways including the Toll-like Receptors. However, aging is also characterized by a constitutive pro-inflammatory environment (inflamm-aging) with persistent low-grade innate immune activation that may augment tissue damage caused by infections in elderly individuals. Thus, immunosenescence in the innate immune system appears to reflect dysregulation, rather than exclusively impaired function.
Shaw
Albert C
AC
Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, 300 Cedar St. Box 208022, New Haven, CT 06520, USA. albert.shaw@yale.edu
Joshi
Samit
S
Greenwood
Hannah
H
Panda
Alexander
A
Lord
Janet M
JM
D016922:Cellular Senescence / Q000276:immunology*; D006801:Humans; D007107:Immune System / Q000502:physiology*; D007113:Immunity, Innate