Establishment of a new intestinal cell line of the grouper (Cephalopholis sonnerati) and immune response to Vibrio harveyi infection.

Abstract

The tomato grouper (Cephalopholis sonnerati) is a commercially valuable species in mariculture, however, infections caused by Vibrio, particularly Vibrio harveyi (V. harveyi), present significant challenges to sustainable aquaculture. To elucidate the immune response to V. harveyi, a novel intestinal cell line of tomato grouper was established, designated TGGI (tomato grouper gastrointestinal), which was cultured in L-15 containing 20 % FBS at 28 °C for over one year and underwent 65 passages. The TGGI cell line shew typical epithelial-like morphology. The origin was confirmed by sequence of COI gene, and karyotype analysis revealed a diploid chromosome number of 2n = 48. TGGI was transfected with pEGFP-N3 plasmid, then emitted strong green fluorescent signals, suggesting potential utility as a tool of exogenous gene functional researches. Furthermore, transcriptomic analysis was performed on TGGI cell lines after infection with V. harveyi at different time points, the results revealed that the majority of differentially expressed genes (DEGs) were enriched in immune-related pathways, including the IL-17, NF-ĸB, Toll-like receptor signaling pathway. Indicating that TGGI cells can recognize pathogen-associated antigens and activate immune responses. In summary, a novel intestinal cell line of grouper, designated TGGI, was successfully established and was suitable for investigating bacterial immune responses. TGGI is expected to play a significant role in multiple fields, particularly by providing a powerful ex vivo tool for elucidating the immune response mechanisms underlying bacterial infection of the intestine.