title: Molecular cloning of Salmo salar Toll-like receptors (TLR1, TLR22, TLR5M and TLR5S) and expression analysis in SHK-1 cells during Piscirickettsia salmonis infection.
abstract: In fish, the innate immune system is the primary response against infection. Toll-like receptors (TLRs) recognize pathogens through pathogen-associated molecular patterns (PAMPs), and some target molecules of TLRs are homologous between fish and mammals. Piscirickettsia salmonis is one of the main pathogens affecting the salmon industry in Chile. Better knowledge of mechanisms underlying its invasive capacity and recognition of target cells is crucial for vaccine development. Therefore, Salmo salar L. TLR1, TLR22, membrane TLR5M and soluble TLR5S sequences were cloned, and expression kinetics were analysed by RT-qPCR in salmon head kidney cells (SHK-1) infected with three different P. salmonis preparations: alive, formaldehyde treated, extract. Clearly, all analysed TLRs were expressed and transcription level changes were revealed at 2 hpi, 12 or 16 hpi and 24 hpi depending on P. salmonis infection scheme. Increased IL1-beta expression confirmed TLR pathway response. Furthermore, significant expression modulations of several members of the TLR pathway in this in vitro model suggest that P. salmonis extract rather than formaldehyde-inactivated bacteria might strengthen the salmon immune system.
authors.affiliation: Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile.
authors.forename: C
authors.initials: C
authors.lastname: Salazar
authors.affiliation: Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile.|Centro FONDAP: Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile.
authors.forename: D
authors.initials: D
authors.lastname: Haussmann
authors.affiliation: Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile.
authors.forename: G
authors.initials: G
authors.lastname: Kausel
authors.affiliation: Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile.|Centro FONDAP: Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile.
authors.forename: J
authors.initials: J
authors.lastname: Figueroa
mesh_terms: D000818:Animals; D002460:Cell Line; D003001:Cloning, Molecular; D005393:Fish Diseases / Q000276:immunology*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D060226:Head Kidney / Q000166:cytology; D053522:Piscirickettsia; D044225:Piscirickettsiaceae Infections / Q000276:immunology / Q000662:veterinary*; D020317:Salmo salar / Q000235:genetics* / Q000276:immunology*; D051193:Toll-Like Receptors / Q000235:genetics*
chemical_list: D051193:Toll-Like Receptors
keywords: Piscirickettsia salmonis; Salmo salar L; Toll-like receptor; innate immune response; leucine-rich regions; pathogen-associated molecular patterns