First characterization of a teleost Epstein-Barr virus-induced gene 3 (EBI3) reveals a regulatory effect of EBI3 on the innate immune response of peripheral blood leukocytes.

Highlights: [•] CsEBI3 expression was detected in multiple tissues and induced by pathogen infection. [•] CsEBI3 was secreted by peripheral blood leukocytes (PBL) upon bacterial stimulation. [•] rCsEBI3 enhanced the immune response and bacterial resistance of PBL. [•] Antibody blocking of CsEBI3 on PBL reduced cell resistance to bacterial invasion. [•] The immunoregulatory function of rCsEBI3 depends on the FN3 domain of the protein. [Copyright &y& Elsevier]