Differential expression of two interferon-y genes in common carp (Cyprinus carpio L.)

Two interferon gamma (IFN-¿) genes are expressed in immune cells of teleost fish and are potentially implicated in B- and T-lymphocyte responses. IFN-¿-2 shows structural and functional characteristics to other vertebrate IFN-¿ genes and is associated with T-lymphocyte function. Expression profiling shows IFN-¿-2 upregulation in T-lymphocytes after phytohemagglutinin (PHA) stimulation in vitro. Unexpectedly, we found IFN-¿-1, which is structurally different from IFN-¿-2, to be expressed in lipopolysacharide (LPS)-stimulated IgM+ (B- lymphocyte enriched) fractions. Expression of T-box transcription factor T-bet, but not of GATA-binding protein 3 (GATA3), correlated with expression of both IFN-¿ genes. In-vivo parasite infection, but as predicted not zymosan-induced inflammation, resulted in concomitant upregulation of T-bet and IFN-¿-2. This corroborates a genuine T-lymphocyte associated role for IFN-¿-2.