Molecular characterization of CD4 homologue in Brown Trout (Salmo trutta)

• Main Author: Ashfaq, Hassan
• Other Authors: El-Matbouli, Mansour, Saalmüller, Armin, Soliman, Hatem
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2021
• Subjects: Atlantic salmon
• Online Access: https://phaidra.vetmeduni.ac.at/o:1049

Dissertation - Veterinärmedizinische Universität Wien - 2021 Zugriff auf den Volltext nur für Angehörige der Veterinärmedizinischen Universität Wien. Bitte einloggen! Dissertation - University of Veterinary Medicine Vienna - 2021 The full text is only available to university members. Please log in! Since the advent of new infectious diseases, which pose, a huge financial threat to the fish aquaculture industry, the research on fish health issues has been substantial during the last decade. The Immunological aspect is in particularly being considered as one of the vital derivatives in understanding the disease advancement. This study was designed to first characterize and then investigate the facilitating functions of brown trout T-cell marker; CD4, in protectiveness against the Viral Hemorrhagic Septicemia Virus (VHSV) after production of polyclonal antibodies to screen CD4+ cells in some of the cellular functional studies. Moreover, expression assays were also included to have a bigger picture of the immune response in brown trout against the virus. There were three genes CD4-1, CD4-2a, and CD4- 2b, cloned and characterized in brown Trout. The first cDNA of CD4-1 contained four immunoglobulin superfamily-like domains and was 1473 nucleotides long, with an open reading frame (ORF) encoding 490 amino acids. The CD4-2 gene appeared to be duplicated and the variants are named CD4-2a and CD4-2b that were 945 and 999 nucleotides long with 2 immunoglobulin superfamily-like domains and containing ORFs with 313 and 331 amino acids, respectively. All CD4 genes of brown trout demonstrated comparable characteristics with mammalian CD4: containing extracellular immunoglobulin-like domains as well as cytoplasmic domains (Lck), tyrosine-based activation motifs. In spite the sequence identities to mammals were low (13- 15%) they are homologous to mammalian CD4, this is also true for other published salmonids sequences. The translated brown trout CD4-1 protein sequence has a 95% and 89% identity with Atlantic salmon and ...