Glycan-mediated interactions of infectious hypodermal and hematopoietic necrosis virus (IHHNV) with host tissues in...

Infectious hypodermal and hematopoietic necrosis virus (IHHNV) poses a significant threat to global shrimp aquaculture, causing substantial economic losses due to Runt Deformity Syndrome (RDS) in susceptible species, particularly Penaeus vannamei. Despite its widespread impact, the molecular mechanisms underlying IHHNV's tissue tropism and host entry remain poorly understood. This study investigated the role of host glycans in mediating IHHNV attachment and infection, focusing on the interaction between virus-like particles (VLPs) of IHHNV and glycan profiles in P. vannamei tissues. Using recombinant IHHN-VLPs, we demonstrated preferential binding to muscle and gill tissues, with significantly higher affinity compared to the hepatopancreas. Lectin-based assays and mass spectrometry revealed that these tissues were enriched in oligomannosylated N-glycans substituted or not with fucose, terminal N-acetylglucosamine (GlcNAc) and sulfate groups as well as complex O-glycans showing very unusual structural features such as substituted fucose residues and terminal N-acetylgalactosamine residues. Inhibition assays on ELISA, Western blot and histochemistry on shrimp's tissues modified with lectins (ConA, WGA, AAL) and glycosidases (PNGase-F, mannosidase, fucosidase) demonstrated that identified mannosylated and fucosylated glycans were essential for IHHNV recognition. These findings highlight the importance of glycan-mediated interactions in IHHNV infection, suggesting that high-mannose N-glycans and fucosylated O-glycans serve as primary attachment factors. The conservation of these glycan motifs across crustacean species implies their potential as broad-spectrum viral targets. This study not only advances our understanding of IHHNV pathogenesis but also opens avenues for developing glycan-based antiviral strategies, such as competitive inhibitors or targeted glycosidase treatments, to mitigate viral outbreaks in shrimp aquaculture.