Functional characterization of four TIR domain-containing adaptors, MyD88, TRIF, MAL, and SARM in mandarin fish Siniperca chuatsi

• Published in: Developmental and comparative immunology 2021-09, Vol.122, p.104110-104110, Article 104110
• Main Authors: Wang, Kai Lun, Chen, Shan Nan, Li, Li, Huo, Hui Jun, Nie, Pin
• Format: Article
• Language: English
• Subjects: Adapters; Adaptor proteins; Adaptor Proteins, Vesicular Transport - genetics; Adaptor Proteins, Vesicular Transport - metabolism; Animals; Armadillo Domain Proteins - genetics; Armadillo Domain Proteins - metabolism; Cell Line; Cytoplasm; Domains; Fish; Fish Diseases - immunology; Fish Diseases - virology; Fluorescence; Fluorescence in situ hybridization; Fluorescence microscopy; Gene expression; Genes; Head Kidney - cytology; Head Kidney - immunology; HEK293 Cells; Homology; Humans; Immunoprecipitation; Interferon; Interferon Type I - genetics; Interferon Type I - immunology; Interleukin 1; Intestine; Kidneys; Lipopolysaccharides; Lipopolysaccharides - immunology; Lymphocytes; Lymphocytes - immunology; MAL; Mandarin fish; Membrane Glycoproteins - genetics; Membrane Glycoproteins - metabolism; Mucosa; MyD88; MyD88 protein; Myeloid Differentiation Factor 88 - genetics; Myeloid Differentiation Factor 88 - metabolism; NF-kappa B - metabolism; NF-κB protein; Overexpression; Perciformes - immunology; Perciformes - virology; Poly I-C - immunology; Polyinosinic:polycytidylic acid; Protein Domains; Receptors; Receptors, Interleukin-1 - genetics; Receptors, Interleukin-1 - metabolism; Regulatory mechanisms (biology); Rhabdoviridae - immunology; SARM; Signal transduction; Signal Transduction - physiology; Signaling; Siniperca chuatsi; Toll-like receptors; Transcriptional Activation; TRIF; Vertebrates; Virus Replication - immunology
• ISSN: 0145-305X; 1879-0089
• DOI: 10.1016/j.dci.2021.104110

Toll/interleukin-1 receptor (TIR) domain-containing adaptors, serve as pivotal signal transduction molecules in Toll-like receptor (TLR) signalling pathway to mediate downstream signalling cascades. In this study, four TIR-domain containing adaptors, MyD88, TRIF, MAL and SARM, were identified in mandarin fish Siniperca chuatsi, and they all contain TIR domains, of which MyD88 and SARM had high sequence homology with their vertebrate homologues. The expression analysis at mRNA level indicated that these genes were ubiquitously distributed in different tissues, being high in immune- and mucosa-related tissues such as head-kidney and intestine. The transcripts of these adaptor genes were up-regulated by poly(I:C) and LPS stimulation in isolated head-kidney lymphocytes (HKLs) of mandarin fish. Fluorescence microscopy revealed that all these molecules were localized in cytoplasm, and further investigations showed that the over-expression of MyD88, TRIF and MAL activated the NF-κB, ISRE or type Ι IFN promoters and inhibited SVCV replication, whereas their antiviral effects were significantly impaired when co-transfected with SARM. It was also confirmed by co-immunoprecipitation (Co-IP) that SARM interacts separately with MyD88, TRIF and MAL, and MAL interacts with MyD88. However, the regulatory mechanisms of these adaptors involved in signalling pathways of different TLRs should be of interest for further research. •Four TIR domain-containing adaptor genes were identified in mandarin fish.•These cytosolicly localized adaptors were constitutively expressed.•These adaptors responded to the stimulation of poly(I:C) and LPS in lymphocytes.•MyD88, TRIF, MAL induced significantly the activity of NF-κB and IFN promoters.•SARM interacted with other adaptors to inhibit the promoter activation.