LAUSR

Abstract Despite increased global interest in Chinook salmon aquaculture, little is known of their viral immune defenses. This study describes the establishment and characterization of a continuous cell line derived from Chinook salmon spleen, CHSS, and its use in innate immune studies. Optimal growth was seen at 14–18 °C when grown in Leibovitz's L‐15 media with 20% fetal bovine serum. DNA analyses confirmed that CHSS was Chinook salmon and genetically different from the only other available Chinook salmon cell line, CHSE‐214. Unlike CHSE‐214, CHSS could bind extracellular dsRNA, resulting in the rapid and robust expression of antiviral genes. Receptor/ligand blocking assays confirmed that class A scavenger receptors (SR‐A) facilitated dsRNA binding and subsequent gene expression. Although both cell lines expressed three SR‐A genes: SCARA3, SCARA4, and SCARA5, only CHSS appeared to have functional cell‐surface SR‐As for dsRNA. Collectively, CHSS is an excellent cell model to study dsRNA‐mediated innate immunity in Chinook salmon. HighlightsDevelopment of a novel Chinook salmon cell line, CHSS.CHSS can bind extracellular dsRNA, unlike CHSE‐214.Both CHSE‐214 and CHSS express scavenger receptors.CHSS can be used to study Chinook salmon antiviral responses in vitro.