Molecular characterization of a T cell co-stimulatory receptor, CD28 of rock bream (Oplegnathus fasciatus): Transcriptional expression during bacterial and viral stimulation. Issue 66 (July 2017)

• Record Type: Journal Article
• Authors: Jeswin, Joseph; Jeong, Seon-Myeong; Jeong, Ji-Min; Bae, Jin-Sol; Kim, Mu-Chan; Kim, Do-Hyung; Park, Chan-Il
• Is Part Of: Fish & shellfish immunology. Issue 66(2017)
• Page Start: 354
• Page End: 359
• Publication Date: 2017-07
• Subjects: CD28 -- Rock bream -- RSIV -- T cell receptor -- Co-stimulatory receptor; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2017.05.013
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: CD28 is a co-stimulatory receptor that provides a critical second signal alongside T cell receptors for the activation of naive T cells. We characterized the CD28 gene of rock bream, which has a deduced amino acid sequence of 221 residues with an extracellular Ig-superfamily V domain, transmembrane region, and cytoplasmic tail. The conservation in domain structures and other motifs shows that it is highly likely that RbCD28 is a homologue of mammalian CD28 and may have related co-stimulatory functions. RbCD28 is constitutively expressed in most tissues that were analysed, with a relatively higher expression in teleost lymphoid organs, such as spleens, gills, trunk kidneys and skin. Unlike human CD28, RbCD28 is highly expressed in skin and gill-associated lymphoid organs. Although gills showed constitutive expression of RbCD28 in control animals, after a pathogen challenge, induction of CD28 was low, particularly in RSIV and E. tarda infection. Whereas induction of RbCD28 was observed in kidney during E. tarda and S. iniae infection, downregulation was observed during RSIV infection. In the case of the liver, E. tarda caused an initial upregulation of RbCD28. RbCD28 activation of T cells in the spleen was limited to S. iniae infection. Activation of RbCD28 observed in lymphoid organs during infection of various pathogens shows its key role as a co-stimulatory receptor of T cells. Highlights: CD28 a T cell costimulatory receptor is identified in Rock bream. Conservation in domain and motifs shows that RbCD28 is a homolog of mammalian CD28. It was highly expressed in various teleost lymphoid organs including gill and skin. E. tarda, S. iniae and RSIV infection caused differential expression of RbCD28 in lymphoid organs. Activation of RbCD28 in lymphoid organs during infection shows its key role as a costimulatory receptor of T cells.