Regulation of recombinant Trichinella spiralis 53-kDa protein (rTsP53) on alternatively activated macrophages via STAT6 but not IL-4Rα in vitro

• RTsP53 has regulatory effects on murine peritoneal macrophages in vitro.
• RTsP53 can inhibit inflammatory factors on macrophages by inducing macrophages to alternative activation.
• The effect of rTsP53 on macrophages is dependent on STAT6 not IL-4Rα.

Classically activated macrophages (M1) or alternatively activated macrophages (M2) have different functions during helminth infections including Trichinella spiralis (T. spiralis). The excretory/secretory antigens (ESA) of T. spiralis can inhibit macrophage pro-inflammatory cytokines production. However, the specific molecules of ESA that regulate macrophages have not been identified. We previously reported that recombinant T. spiralis derived molecule 53-kDa protein (rTsP53) had protected mice from colitis. Furthermore, in the present study in vitro, we investigated rTsP53 showed anti-inflammatory function by inducing peritoneal macrophages to M2 with expressing M2 molecules of mannose receptor (MR), a novel mammalian lectin (Ym1), arginase-1 (Arg1), and interleukin (IL)-10. Next, we found the effect of rTsP53 on M2 independently of IL-4Rα. But rTsP53 can act dependently on signal transducers and activators of transcription 6 (STAT6). These results further imply that rTsP53 has potential as prospective immuno-therapeutics for inflammatory disorders.