Macrophage hypo-responsiveness to interferon-γ in aged mice is associated with impaired signaling through Jak-STAT

Analysis of interaction of cloned human and/or sheep fetal hemoglobin γ-chain and LPS in augmenting induction of inflammatory cytokine production in vivo and in vitro

“…Thus, although at the cellular level, the T cell arm of the immune response may be a primary focus for age-related changes [16][17][18][19], the ultimate altered resistance to, e.g., infectious disease may represent a reflection of a direct and/or indirect effect of aging on macrophages and other cells of the innate immune system [20][21][22][23][24][25][26][27][28].…”

The aging innate immune system

“…Exposure of macrophages from both age groups to IL-2, however, failed to yield an age-dependent difference with respect to TNF-a and IL-6 production, which was markedly attenuated relative to LPS stimulation. Additional evidence reveals that peritoneal macrophages from aged mice have a decreased response following IFN-g exposure, implicating impaired signaling through the Jak-STAT pathway of signal activation [24].…”

Ageing and the immune system: focus on macrophages

“…Studies in rats have demonstrated a 75% decrease in the ability of macrophages from old rats to produce superoxide anion following incubation with IFN-γ [80]. Yoon et al reported reduced STAT-1α phosphorylation in response to IFN-γ in macrophages from old mice compared to young mice [81], indicating that ageing alters intracellular signalling in macrophages.…”