Comparative study on pattern recognition receptors in non-teleost ray-finned fishes and their evolutionary significance in primitive vertebrates
Pattern recognition receptors (PRRs) play important roles in innate immunity system and trigger the specific pathogen recognition by detecting the pathogen-associated molecular patterns. The main four PRRs components including Toll-like receptors (TLRs), RIG-I-like receptors (RLRs), NOD-like receptors (NLRs) and C-type lectin receptors (CLRs) were surveyed in the five genomes of non-teleost ray-finned fishes (NTR) including bichir (Polypterus senegalus), American paddlefish (Polyodon spathula), alligator gar (Atractosteus spatula), spotted gar (Lepisosteus oculatus) and bowfin (Amia calva), representing all the four major basal groups of ray-finned fishes. The result indicates that all the four PRRs components have been well established in these NTR fishes. In the RLR-MAVS signal pathway, which detects intracellular RNA ligands to induce production of type I interferons (IFNs), the MAVS was lost in bichir particularly. Also, the essential genes of recognition of Lipopolysaccharide (LPS) commonly in mammals like MD2, LY96 and LBP could not be identified in NTR fishes. It is speculated that TLR4 in NTR fishes may act as a cooperator with other PRRs and has a different pathway of recognizing LPS compared with that in mammals. In addition, we provide a survey of NLR and CLR in NTR fishes. The CLRs results suggest that Group V receptors are absent in fishes and Group II and VI receptors are well established in the early vertebrate evolution. Our comprehensive research of PRRs involving NTR fishes provides a new insight into PRR evolution in primitive vertebrate.
Keywordspattern recognition receptors (PRR) Toll-like receptors (TLR) RIG-I-like receptors (RLR) C-type lectin receptors (CLR) NOD-like receptors (NLR) innate immunity
Unable to display preview. Download preview PDF.
This work was supported by the National Natural Science Foundation of China (31372190).
- Hall, T.A. (1999). Bioedit: A user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symp Series 41, 95–98.Google Scholar
- Oshiumi, H., Tsujita, T., Shida, K., Matsumoto, M., Ikeo, K., and Seya, T. (2003). Prediction of the prototype of the human toll-like receptor gene family from the pufferfish, Fugu rubripes, genome. Immunogenetics 54, 791–800.Google Scholar
- Reikine, S., Nguyen, J.B., and Modis, Y. (2014). Pattern recognition and signaling mechanisms of RIG-I and MDA5. Front Immunol 5.Google Scholar
- Sepulcre, M.P., Alcaraz-Perez, F., Lopez-Munoz, A., Roca, F.J., Meseguer, J., Cayuela, M.L., and Mulero, V. (2009). Evolution of lipopolysaccharide (LPS) recognition and signaling: Fish TLR4 does not recognize LPS and negatively regulates NF-kB activation. J Immunol 182, 1836–1845.CrossRefGoogle Scholar
- Tahoun, A., Jensen, K., Corripio-Miyar, Y., McAteer, S., Smith, D.G.E., McNeilly, T.N., Gally, D.L., and Glass, E.J. (2017). Host species adaptation of TLR5 signalling and flagellin recognition. Scientific Reports 7.Google Scholar
- Tsoi, S., Park, K.C., Kay, H.H., O’Brien, T.J., Podor, E., Sun, G., Douglas, S.E., Brown, L.L., and Johnson, S.C. (2006). Identification of a transcript encoding a soluble form of toll-like receptor 5 (TLR5) in atlantic salmon during Aeromonas salmonicida infection. Vet Immunol Immunopathol 109, 183–187.CrossRefGoogle Scholar
- Tsukada, H., Fukui, A., Tsujita, T., Matsumoto, M., Iida, T., and Seya, T. (2005). Fish soluble toll-like receptor 5 (TLR5s) is an acute-phase protein with integral flagellin-recognition activity. Int J Mol Med 15, 519–525.Google Scholar