title: Molecular cloning and comparative responses of Toll-like receptor 22 following ligands stimulation and parasitic infection in yellowtail (Seriola lalandi).
abstract: TLR22 is exclusively present in teleosts and amphibians and is expected to play the distinctive role in innate immunity. In this study, we cloned the full-length cDNA sequence of yellowtail (Seriola lalandi) TLR22 (SlTLR22). The complete cDNA sequence of SlTLR22 was 4208 bp and encodes a polypeptide of 961 amino acids. Analysis of the deduced amino acid sequence indicated that SlTLR22 has typical structural features of proteins belonging to the TLR family. These included 17 LRR domains (residues 91-633) and one C-terminal LRR domain (LRR-CT, residues 693-744) in the extracellular region, and a TIR domain (residues 800-943) in the cytoplasmic region. Comparison with homologous proteins showed that the deduced SlTLR22 has the highest sequence identity to turbot TLR22 (76%). Quantitative real-time PCR (qPCR) analysis demonstrated the constitutive expression of SlTLR22 mRNA in all examined tissues with higher levels in the head kidney, intestine, skin and spleen. Further, SlTLR22 expression was significantly up-regulated following TLR ligands injection with lipopolysaccharide (LPS), CpG ODN2006 and polyinosinic: polycytidylic acid (poly I:C) in spleen and liver. Amyloodinium ocellatum infection also induced a high expression of SlTLR22 in spleen, intestine, muscle, skin and gill, with maximum increases ranging from 1000 to 100 fold upon different ligands and organs. Finally, histological examination in gill tissue confirmed infection by the parasite and histopathological lesion was observed also in spleen and skin. These findings suggest a possible role of SlTLR22 in the immune responses to the infections of a broad range of pathogens that include DNA and RNA viruses and parasites.
authors.affiliation: Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Instituto Politécnico Nacional 195, Playa Palo de Santa Rita, La Paz, B.C.S. 23096, Mexico.
authors.forename: Martha
authors.initials: M
authors.lastname: Reyes-Becerril
authors.affiliation: Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Instituto Politécnico Nacional 195, Playa Palo de Santa Rita, La Paz, B.C.S. 23096, Mexico.
authors.forename: Felipe
authors.initials: F
authors.lastname: Ascencio-Valle
authors.affiliation: Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Instituto Politécnico Nacional 195, Playa Palo de Santa Rita, La Paz, B.C.S. 23096, Mexico.
authors.forename: Erika
authors.initials: E
authors.lastname: Alamillo
authors.affiliation: Laboratory of Genome Science, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-ku, Tokyo 108-8477, Japan.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Hirono
authors.affiliation: Laboratory of Genome Science, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-ku, Tokyo 108-8477, Japan.
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Kondo
authors.affiliation: Laboratory of Genome Science, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-ku, Tokyo 108-8477, Japan.
authors.forename: Walissara
authors.initials: W
authors.lastname: Jirapongpairoj
authors.affiliation: Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Instituto Politécnico Nacional 195, Playa Palo de Santa Rita, La Paz, B.C.S. 23096, Mexico. Electronic address: eangulo@cibnor.mx.
authors.forename: Carlos
authors.initials: C
authors.lastname: Angulo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004141:Dinoflagellida / Q000502:physiology; D005393:Fish Diseases / Q000276:immunology* / Q000382:microbiology / Q000469:parasitology / Q000821:virology; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D007113:Immunity, Innate; D008024:Ligands; D008070:Lipopolysaccharides / Q000494:pharmacology; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology; D009928:Organ Specificity; D010473:Perciformes; D010802:Phylogeny; D011070:Poly I-C / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment / Q000662:veterinary; D051193:Toll-Like Receptors / Q000235:genetics* / Q000378:metabolism
chemical_list: C513533:CpG ODN 2006; D029941:Fish Proteins; D008024:Ligands; D008070:Lipopolysaccharides; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D051193:Toll-Like Receptors; D011070:Poly I-C
keywords: Expression modulation; TLR22; Yellowtail Seriola lalandi