Nippostrongylus brasiliensis and Heligmosomoides polygyrus exert anti-inflammatory effects through distinct immunomodulatory mechanisms in murine macrophages in vitro.

Abstract

Hookworm infections affect hundreds of millions of people worldwide and rank among the most significant neglected tropical diseases in terms of morbidity. Due to the inverse correlation between hookworm infection and the incidence of immune-mediated inflammatory diseases, considerable research has focused on understanding how parasitic helminths modulate host inflammation. Heligmosomoides polygyrus and Nippostrongylus brasiliensis are two hookworm-like rodent models widely used to investigate fundamental aspects of immune regulation. However, no comparative study has yet analysed the distinct immunological pathways activated by these helminths in their hosts. In this study, we compared cytokine profiles and M1/M2 macrophage polarization markers induced by H. polygyrus and N. brasiliensis, alongside proteomic pathways involved in their activation, using the RAW 264.7 murine macrophage cell line. H. polygyrus downregulated proinflammatory cytokines such as TNF-α and MCP-1, whereas N. brasiliensis did not affect TNF-α expression. Both parasites upregulated Th2 and regulatory cytokines, including IL-4 and TGF-β. Furthermore, H. polygyrus predominantly polarized macrophages toward an M2 phenotype, while N. brasiliensis maintained a balanced M1/M2 profile. Proteomic analysis revealed that N. brasiliensis and H. polygyrus exert their anti-inflammatory effects through distinct mechanisms, with N. brasiliensis acting via peripheral pathways and H. polygyrus via central regulatory mechanisms.