Re examination of the rainbow trout (Oncorhynchus mykiss) immune response to flagellin: Yersinia ruckeri flagellin is a potent activator of acute phase proteins, anti microbial peptides and pro inflammatory cytokines in vitro.
Flagellin is the principal component of bacterial flagellum and a major target of the host immune system. To provide new insights into the role of flagellin in fish immune responses to flagellated microorganisms, a recombinant flagellin from Yersinia ruckeri (rYRF) was produced and its bioactivity investigated in the trout macrophage cell line RTS 11 and head kidney cells. rYRF is a potent activator of pro inflammatory cytokines, acute phase proteins, antimicrobial peptides and subunits of the IL 12 cytokine family. This and the synergy seen with IFN g to enhance further expression of specific IL 12 and TNF a isoforms may suggest that flagellin could be a useful immune stimulant or adjuvant for use in aquaculture. Gene paralogues were often differentially modulated, highlighting the need to study all of the paralogues of immune genes in fish to gain a full understanding of the effects of PAMPs or other stimulants, and the potential immune responses elicited.
Developmental and comparative immunology