Location: Warmwater Aquaculture Research UnitTitle: Channel catfish CD8a and CD8ß co-receptors characterization expression and polymorphism Author
Submitted to: Fish and Shellfish Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/16/2011
Publication Date: 3/1/2011
Publication URL: http://handle.nal.usda.gov/10113/55437
Citation: Quiniou, S., Sahoo, M., Edholm, E., Bengten, E., Wilson, M. 2011. Channel catfish CD8a and CD8ß co-receptors characterization expression and polymorphism. Fish and Shellfish Immunology. 30(3):894-901. Interpretive Summary: CD8 molecules are the cell surface markers of abT cytotoxic cells. CD8 cytotoxic cells kill/destroy virus-infected cells hence prevent pathogen multiplication and spreading. This paper reports the identification and characterization of both CD8a and CD8ß molecules in channel catfish. The identification of such important T cell markers will allow researchers to study the role of catfish CD8 positive cytotoxic T cells during viral infection. The ability to track or monitor CD8 positive cytotoxic cells will also be useful in vaccine design since the presence of these cells will indicate a cellular immune response has been initiated.
Technical Abstract: In this study we report the identification and characterization of channel catfish, Ictalurus punctatus CD8a and CD8ß genes. Both genes encode predicted proteins containing a leader, a immunoglobulin superfamily V domain, a stalk/hinge region, a transmembrane region and a positively charged cytoplasmic tail (CYT) containing the conserved teleost C-X-H motif. Catfish CD8a and CD8ß are encoded as single copy genes and as in other vertebrates exhibit a conserved head to tail synteny; the CD8ß gene is found 14.1 kb upstream of the CD8a gene. Both CD8a and CD8ß transcripts showed a low degree of polymorphism. Finally, as determined by q-PCR both CD8a and CD8ß are expressed in various catfish lymphoid tissues with the highest expression observed in thymus from 2 month old catfish-fry. In the future these results will provide us with the basis to evaluate the role of CD8+ CTL cells in response to immunization or infection in the catfish.