title: TLR21's agonists in combination with Aeromonas antigens synergistically up-regulate functional TLR21 and cytokine gene expression in yellowtail leucocytes.
abstract: The purpose of this study was to characterize the TLR21 gene from yellowtail (Seriola lalandi) and its functional activity using TLR agonist stimulation and Aeromonas antigens. The TLR21 nucleotide sequence from yellowtail was obtained using the whole-genome shotgun sequencing method and bioinformatics tools. Basal TLR21 gene expression was analyzed in several tissues. Subsequently, the gene expression of TLR21 and cytokines IL-1β and TNF-α was evaluated in TLR agonist (CpG-ODN2006, LPS, and Poly I:C) exposing head kidney leucocytes, which were then subjected to Aeromonas antigen stimulation. The yellowtail full-length cDNA sequence of SlTLR21 was 3615 bp (980 aa) showing a high degree of similarity with the counterparts of other fish species and sharing the common structural architecture of the TLR family, including LRR domains, one C-terminal LRR region, and a TIR domain. Gene expression studies revealed the constitutive expression of TLR21 mRNA in all the analyzed tissues; the highest levels were observed in spleen and head kidney where they play an important role in the fish immune system. Transcripts of TLR21 and the downstream IL-1β and TNF-α cytokine genes were most strongly up-regulated after exposure to the TLR agonists following Aeromonas antigen stimulation, suggesting they are involved in immune response. The results indicated that TLR agonists, in combination with Aeromonas antigens in head kidney leucocytes, synergistically enhance TLR21 and cytokines in yellowtail.
authors.affiliation: Grupo de Inmunología & Vacunología, 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: Grupo de Inmunología & Vacunología, 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: 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: Fish Innate Immune System Group, Department of Cell Biology and Histology, Faculty of Biology, Campus of International Excellence, Campus Mare Nostrum, University of Murcia, Murcia, Spain.
authors.forename: Maria Angeles
authors.initials: MA
authors.lastname: Esteban
authors.affiliation: Grupo de Inmunología & Vacunología, 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: Grupo de Inmunología & Vacunología, 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: D000333:Aeromonas / Q000276:immunology*; D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D003001:Cloning, Molecular; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D005399:Fishes / Q000276:immunology*; D016905:Gram-Negative Bacterial Infections / Q000276:immunology*; D060226:Head Kidney / Q000378:metabolism*; D007113:Immunity, Innate; D007962:Leukocytes / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology; D009838:Oligodeoxyribonucleotides / Q000276:immunology; D010802:Phylogeny; D011070:Poly I-C / Q000276:immunology; D017422:Sequence Analysis, DNA; D013154:Spleen / Q000378:metabolism*; D051193:Toll-Like Receptors / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D059467:Transcriptome
chemical_list: D000942:Antigens, Bacterial; D029941:Fish Proteins; D008070:Lipopolysaccharides; C000615642:ODN2006; D009838:Oligodeoxyribonucleotides; D051193:Toll-Like Receptors; D011070:Poly I-C
keywords: Aeromonas antigens; Agonist TLRs; Cytokine gene expression; Seriola lalandi; TLR21