Cytokines play a key role in the immune system. When pathogen infection occurs, macrophages undergo phagocytosis first, accompanied with inflammatory cytokines secretion. FAM19A4 is a novel cytokine identified by the strategy of immunogenomics. It is a classical secreted protein, low expressed in most normal tissues, but is up-regulated in inflammatory stimulated monocytes-macrophages. FAM19A4 can enhance phagocytosis of murine macrophages against zymosan both in vitro and in vivo by noticeably increasing the phosphorylation of Akt, but reduce TNF-α secretion in zymosan-challenged macrophages by impacting activation of p38 and ERK1/2 in NF-κB pathway, due to the degradation of p65 both in nucleus and cytoplasm. These findings provide a novel cytokine FAM19A4 expressed by stimulated macrophages, which can promote phagocytosis of macrophages by activating Akt, but impact TNF-α increasing with challenge by inhibiting NF-κB pathway.
- Copyright © 2013 by The American Association of Immunologists, Inc.