A CXC chemokine gene, CXCL12, from rock bream, Oplegnathus fasciatus: Molecular characterization and transcriptional profile

• Published in: Fish & shellfish immunology Vol. 45; no. 2; pp. 560 - 566
• Main Authors: Thulasitha, William Shanthakumar, Umasuthan, Navaneethaiyer, Whang, Ilson, Lim, Bong-Soo, Jung, Hyung-Bok, Noh, Jae Koo, Lee, Jehee
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2015
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Brain - metabolism; Cells, Cultured; Chemokine CXCL12 - chemistry; Chemokine CXCL12 - genetics; Chemokine CXCL12 - immunology; Chemokine CXCL12 - metabolism; Chemokines; CXCL12; DNA Virus Infections - immunology; DNA Virus Infections - veterinary; Edwardsiella tarda; Enterobacteriaceae Infections - immunology; Enterobacteriaceae Infections - veterinary; Fish Diseases - immunology; Fish Proteins - chemistry; Fish Proteins - genetics; Fish Proteins - immunology; Fish Proteins - metabolism; Gills - metabolism; Head Kidney - immunology; Head Kidney - metabolism; Immune challenge; Intestines - metabolism; Iridoviridae; Kidney - metabolism; Leukocytes - immunology; Liver - metabolism; Models, Molecular; Molecular Sequence Data; mRNA expression; Muscles - metabolism; Oplegnathus fasciatus; Perciformes - genetics; Perciformes - immunology; Perciformes - metabolism; Spleen - immunology; Spleen - metabolism; Streptococcal Infections - immunology; Streptococcal Infections - veterinary; Streptococcus; Transcription, Genetic; CXCL12; Immune challenge; Chemokines; mRNA expression
• ISSN: 1050-4648; 1095-9947
• DOI: 10.1016/j.fsi.2015.05.002

Chemokines are small, structurally related chemotactic cytokines characterized by the presence of conserved cysteine residues. In the present study, we identified the cDNA of a CXC chemokine from Oplegnathus fasciatus, designated as OfCXCL12. An open reading frame of 297 bp encoded a 98 amino acid peptide with a putative signal peptide of 23 amino acids. The CXC family-specific small cytokine domain (SCY), which is highly conserved among vertebrates, was located between residues 29 and 87. The characteristic conserved cysteine residues in the CXC motif of OfCXCL12 were separated by tyrosine (Y). Similar to other vertebrate CXCL12 proteins, OfCXCL12 also lacked the ELR motif and hence belongs to ELR− subfamily. Phylogenetic analysis revealed two distinct clades, consisting of fish and tetrapod CXCL12 homologs. Constitutive expression with significantly higher levels of OfCXCL12 mRNA transcription was detected in immune-related organs, including the head kidney, spleen, and kidney. Infection with bacterial and viral agents led to significant upregulation of mRNA expression in both the head kidney and spleen, in a stimulant-specific manner. Stimulation of peripheral blood leukocytes by the mitogen concanavalin-A significantly induced OfCXCL12 transcription. Results from the present study suggest an important role for OfCXCL12 in immune defense against bacterial and viral infection in rock bream. •Homolog of CXCL12 was identified and cloned from Rock bream (OfCXCL12).•OfCXCL12 was ubiquitously expressed in examined tissues.•OfCXCL12 mRNA expression in immune tissues was significantly modulated by pathogenic invasion.•In vitro treatment of Concanavalin-A significantly induced the transcription of OfCXCL12.