Decapod iridescent virus 1 (DIV1) 168L can target cuticle protein 8 from Litopenaeus vannamei

Decapod iridescent virus 1 (DIV1) stands as a significant pathogen affecting crustaceans, posing a grave threat to the shrimp industries in aquaculture dependent nations. Within the Iridoviridae family, the conserved envelope protein DIV1-168L plays a pivotal role in virion entry. Nonetheless, the host factors that interact with 168L remain unidentified. To address this gap, we established a cDNA library derived from Litopenaeus vannamei gill tissue and conducted yeast two-hybrid screening to identify host factors that interact with 168L. Additionally, we performed co-immunoprecipitation assays to verify the interaction between cuticle protein 8 (CP8) and 168L. Expression pattern analysis revealed the presence of CP8 transcripts in the gill and epidermis. Furthermore, immunohistochemistry results demonstrated the expression of CP8 in gill cells and its localization in the gill filament epithelium. Fluorescence analysis indicated that full-length CP8 colocalized with 168L in the cytoplasm of Sf9 cells. Removal of the signal peptide from the N-terminal of CP8 eliminated its concentration in the cytoplasm. Additionally, CP8 expression was significantly inhibited during DIV1 infection. Therefore, our research contributes to a better understanding of the entry mechanism of iridovirids. The GenBank accession number for the DIV1 sequence is MF197913.1.