Identification of an anti-lipopolysaccharide factor AV-R isoform (LvALF AV-R) related to Vp_PirAB-like toxin resistance in Litopenaeus vannamei

• Published in: Fish & shellfish immunology Vol. 84; pp. 178 - 188
• Main Authors: Tinwongger, Sasiwipa, Thawonsuwan, Jumroensri, Kondo, Hidehiro, Hirono, Ikuo
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.01.2019
• Subjects: AHPND; Immune; Penaeid shrimp; Resistance; Vibrio parahaemolyticus; Resistance; Vibrio parahaemolyticus; AHPND; Penaeid shrimp; Immune
• ISSN: 1050-4648; 1095-9947
• DOI: 10.1016/j.fsi.2018.10.005

Acute hepatopancreatic necrosis disease (AHPND) is a shrimp farming disease, caused by the pathogenic Vibrio parahaemolyticus carrying a plasmid encoding Vp_PirAB-like toxins. Formalin-killed cells of V. parahaemolyticus AHPND-causing strain D6 (FKC-VpD6) were used to select Vp_PirAB-like toxin-resistant Litopenaeus vannamei by oral administration. Stomach and hepatopancreas tissues of shrimps that survived for one week were subjected to RNA sequencing. Differentially expressed genes (DEGs) between surviving shrimp, AHPND-infected shrimp, and normal shrimp were identified. The expressions of 10 DEGs were validated by qPCR. Only one gene (a gene homologous to L. vannamei anti-lipopolysaccharide factor AV-R isoform (LvALF AV-R)) was expressed significantly more strongly in the hepatopancreas of surviving shrimp than in the other groups. Significantly higher expression of LvALF AV-R was also observed in shrimp that survived two other trials of FKC-VpD6 selection. Recombinant ALF AV-R bound to LPS, PGN, Gram-negative bacteria, and some Gram-positive bacteria in ELISAs. ALF AV-R recombinant protein did not interact with native Vp_PirAB-like toxin in an ELISA or a Far-Western blot. For L. vannamei orally fed ALF AV-R protein for 3 days, the survival rate following challenge with VpD6-immersion was not significantly different from that of shrimp fed two control diets. These results suggest that LvALF AV-R expression was induced in the hepatopancreas of shrimp in response to the presence of Vp_PirAB-like toxin, although other factors might also be involved in the resistance mechanism. •Genes associated with Vp_PirAB-like toxin-resistant shrimp were identified by RNA-seq.•LvALF AV-R mRNA was significantly higher in the hepatopancreas of resistant shrimp.•VpAHPND-immersion and FKC of non-VpAHPND did not induced LvALF AV-R.•Recombinant ALF AV-R bound to bacterial proteins, but not Vp_PirAB-like toxin.•Shrimp fed ALF AV-R showed higher survival at 24 hpi with VpAHPND than PBS group.