Expression analysis of nine Toll-like receptors in yellow catfish (Pelteobagrus fulvidraco) responding to Aeromonas hydrophila challenge. Issue 63 (April 2017)

• Record Type: Journal Article
• Authors: Zhang, Xiao-Ting; Zhang, Gui-Rong; Shi, Ze-Chao; Yuan, Yu-Jie; Zheng, Huan; Lin, Li; Wei, Kai-Jian; Ji, Wei
• Is Part Of: Fish & shellfish immunology. Issue 63(2017)
• Page Start: 384
• Page End: 393
• Publication Date: 2017-04
• Subjects: Yellow catfish -- Aeromonas hydrophila -- Toll-like receptors -- Gene expression -- Intraperitoneal injection -- Innate immunity; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2017.02.021
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: Toll-like receptors (TLRs) are important components of pattern recognition receptors (PRRs), which play significant roles in innate immunity to defense against pathogen invasion. Many TLRs have been found in teleosts, but there are no reports about cloning and expression of TLR genes in yellow catfish ( Pelteobagrus fulvidraco ). In this study, we analyzed the sequence characters and the relative mRNA expression levels of nine TLRs (TLR1, TLR2, TLR3, TLR4-1, TLR5, TLR7, TLR8-2, TLR9 and TLR22) in different tissues of yellow catfish. The results showed that all nine TLR genes are highly expressed in head kidney, trunk kidney, spleen and liver, all of which are related to host immunity. Subsequently we used Aeromonas hydrophila as a stimulating agent to detect the expression profiles of these nine TLRs in the liver, spleen, trunk kidney and head kidney of yellow catfish at different time points after injection with killed Aeromonas hydrophila . All nine TLRs responded to A. hydrophila challenge with tissue-specific patterns in different immune tissues. The kinetics of up- or down-regulation of these nine TLRs exhibited a similar trend, rising to an elevated level at first and then falling to the basal level, but the peak value differed at different time points in different tissues. The expression levels of the TLR3, TLR4-1, TLR9 and TLR22 genes were significantly up-regulated after bacterial challenge in the liver, spleen, head kidney and trunk kidney. The relatively high expression of TLR genes in the immune tissues in response to the A. hydrophila challenge indicated that TLRs may play important roles in the innate immune response against gram-negative bacteria in yellow catfish. Highlights: Nine TLR genes were identified in yellow catfish. Deduced amino acid sequences of nine TLRs were analyzed. All the Nine TLRs were mainly expressed in the liver, spleen, head kidney and trunk kidney. All the Nine TLRs responded to A. hydrophila challenge with different expression patterns in immune-related tissues.