Recombinant Miro domain-containing protein of Haemonchus contortus (rMiro-1) activates goat peripheral blood mononuclear cells in vitro

•First molecular and functional characterization of a parasitic nematode Miro-1.•Western blot results showed that rMiro-1 was recognized by the sera of goats experimentally infected with H. contortus.•IFA results indicated that rMiro-1 could bind to the goat PBMCs in vitro.•Treatment of goat PBMCs with various concentrations of rMiro-1 significantly induced the cytokine secretion and nitric oxide (NO) production, enhanced cell proliferation and migration, and strengthened phagocytosis of monocytes•rMiro-1 might have stimulatory potential on goat PBMCs in vitro.

In our previous proteomics study, we identified Miro domain-containing protein (Miro-1), an excretory and secretory product of the pole worm, Haemonchus contortus, binds to goat peripheral blood mononuclear cells (PBMCs) in vivo. However, our understanding of the role of Miro-1and its potential immune impact on goat PBMCs is limited. The aim of the present study was to evaluate the effects of Miro-1 on functions of goat PBMCs in vitro. Recombinant protein (rMiro-1) was expressed in a prokaryote and incubated with goat PBMCs. Western blot analysis showed that rMiro-1 is successfully recognized by goat sera infected with H. contortus. Immunofluorescence analysis using rat antibodies against rMiro-1 indicated that this protein binds to goat PBMCs in vitro.Treatment of goat PBMCs/monocytes with various concentrations of rMiro-1 resulted in the upregulation of IL-2, IL-4, and IL-17, which in turn promoted cell proliferation, migration, the release of NO in PBMCs, and enhancement of phagocytosis of monocytes. These findings suggested that rMiro-1 stimulates PBMCs activity.