Affiliation: | aDivision of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea bDepartment of Surgery, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea cDepartment of Microbiology and Immunology, College of Medicine, Seoul National University, Seoul 110-799, Republic of Korea dCell Signaling Laboratory, Department of Pharmacology, Cancer Research Institute, Research Institute for Medical Sciences, College of Medicine, Chungnam National University, Taejeon 305-764, Republic of Korea eSchool of Bioscience and Biotechnology, Kangwon National University, Chucheon 200-701, Republic of Korea fSchool of Biological Sciences and Technology, Biotechnology Research Institute, Chonnam National University, Kwangju 500-757, Republic of Korea |
Abstract: | CD81, also known as TAPA-1 (target of antiproliferative antibody 1), is a member of the tetraspanin family of proteins and a component of the B cell co-receptor complex. Several studies have shown that CD81 plays significant roles in a variety of immune responses, including activation of B cells and T cells. In this study, we cloned pig Cd81 cDNA using RT-PCR coupled with rapid amplification of cDNA ends (RACE)-PCR and determined the complete cDNA sequence of pig Cd81. Pig Cd81 cDNA contains an open reading frame (711 bp) encoding 236 amino acids. The identity of pig CD81 with those of human, cattle, rat, and mouse are 90.30%, 92.26%, 86.22%, and 86.22%, respectively. Alignment of the CD81 amino acid sequence with those of mammalian species showed that the large extracellular loop (LEL) is the most divergent, whereas other domains are largely conserved. Pig Cd81 mRNA was detected by RT-PCR in a broad range of tissues, including lymphoid tissues as well as nonlymphoid tissues, indicated variety of cellular functions of CD81 in most pig tissues. Flow cytometry analyses demonstrated that human CD81 antibody recognizes a pig CD81 on the cell surface. Further, immunohistochemistry analysis using human CD81 antibody on pig spleen was revealed that CD81 expression is widely diffused in spleen tissue. Future study will be focused on defining the functional role of CD81 during the course of pig infectious diseases. |