Trypanosoma carassii hsp70 increases expression of inflammatory cytokines and chemokines in macrophages of the goldfish (Carassius auratus L.)

We report on the cloning and characterization of Trypanosoma carassii 70 KDa heat shock protein (hsp70). T. carassii hsp70 was secreted/excreted into culture medium in vitro and was recognized by sera from infected fish. Recombinant hsp70 (rhsp70) activated goldfish macrophages and stimulated the production of pro-inflammatory cytokines including interferon gamma (IFNγ), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, (IL)-12 and chemokines CCL-1 and CXCL-8 (IL-8). T. carassii hsp70-induced cytokine expression was abrogated by pronase treatment of macrophages confirming the existence of receptor(s) on goldfish macrophage surface that recognize parasite molecule. Parasite hsp70 also up-regulated the expression inducible nitric oxide synthase (iNOS) isoforms A and B and induced a strong nitric oxide response of goldfish macrophages.