Molecular cloning and expression of IRAK-4, IL-17 and I-κB genes in Haliotis rufescens challenged with Vibrio anguillarum

• Hr-IL17, Hr-IRAK4 and Hr-IκB revealed conservative motifs with homologous proteins.
• The candidate genes showed ubiquitous expression in the analyzed tissues.
• Transcriptional profiling post bacterial challenge in hemocytes showed up-regulation.
• Hr-IκB is modulated at different times by Hr-IL17 and Hr-IRAK4.

The candidate genes interleukin-1 receptor associated kinase 4 (IRAK-4), Interleukin 17 (IL-17) and Inhibitor of NF-κB (I-κB) were cloned and evaluated in Californian abalone (Haliotis rufescens) hemocytes in response to Vibrio anguillarum. Molecular characterization evidenced that HrI-κB has a full cDNA sequence of 3027 bp with an encoding region of 401 amino acids (aa), HrIRAK-4 comprised 1969 bp that encoded for 516 aa, and Hr-IL17 had a full sequence of 806 bp encoding for 165 aa. qPCR analysis showed the higher constitutive expression level of Hr-IL17 in hemocytes; meanwhile Hr-IκB and Hr-IRAK4 gene expression levels were higher in gills and mantle. The assessment of gene expression in hemocytes after infection with V. anguillarum evidences the immune responses of Hr-IκB, Hr-IRAK4, and Hr-IL17 and their relationships through the NF-κB signaling pathway.