Fucosyltransferase 2 is involved in immune-related functions in Penaeus vannamei by modulating antimicrobial peptides’ expression

In mammals fucosyltransferase 2 (FUT2) plays an important regulatory role in inflammation, bacterial or viral infection, and tumor metastasis. However, the specific role of FUT2 in invertebrate immunity has not been reported. Here, the FUT2 homolog of Penaeus vannamei (designated as PvFUT2) was cloned and found to have a full-length cDNA of 1104 bp with an open reading frame (ORF) encoding 316 amino acids. PvFUT2 is constitutively expressed in all shrimp tissues tested with the highest found in intestines. Moreover, PvFUT2 was induced in the main immune organs (hemocytes and hepatopancreas) of shrimp by Gram-positive (Vibrio parahaemolyticus), Gram-negative (Streptococcus iniae) bacteria and virus (White Spot Syndrome Virus), indicating the involvement of PvFUT2 in shrimp antimicrobial response. Intriguingly, PvFUT2 knockdown with or without pathogen challenge reduced the expression of Pvβ-catenin and antimicrobial peptides genes, particularly anti lipopolysaccharide factor and lysozyme. Further analysis revealed that the knockdown of PvFUT2 increased Vibrio abundance in hemolymph and resulted in an increase in shrimp cumulative mortality rate. Thus, during pathogen challenge, the expression of PvFUT2 is induced to regulate β-catenin and subsequently antimicrobial peptides expression to augment shrimp antimicrobial immune response.