Tuyển tập các báo cáo nghiên cứu khoa học quốc tế về bệnh thú y đề tài: Evaluation of expression patterns of feline | J. Vet. Sci. 2000 1 2 97-103 OURNAL OF Veterinary Science Evaluation of expression patterns of feline CD28 and CTLA-4 in feline immunodeficiency virus FIV -infected and FIV antigen-induced PBMC In-Soo Choi Han Sang Yoo Ellen W. Collisson1 Department of Infectious Diseases College of Veterinary Medicine and School of Agricultural Biotechnology Seoul National University Suwon 441-744 Korea Department of Veterinary Pathobiology College of Veterinary Medicine Texas A M University College Station Texas 778434467 It is known that CD28 a positive costimulatory receptor plays a very important role in inducing the optimal stimulation of T lymphocytes. CTLA-4 CD152 however acts as a negative regulator in T lymphocyte activation. The effect of an feline immunodeficiency virus FIV infection on the expression of feline CD28 and CTLA-4 was studied with FIV-infected and uninfected peripheral blood mononuclear cells PBMC using a competitive PCR assay. The nature of CD28 and CTLA-4 expression was also examined with fresh and antigen-stimulated PBMC. FIV infection induced a lower expression of CD28 but a higher expression of CTLA-4 in the infected PBMC than in the uninfected PBMC. Relatively high levels of CD28 expression were demonstrated in both the fresh and the antigen-stimulated PBMC. The expression level of CTLA-4 in the freshly isolated PBMC was rather low however FIV antigen stimulation induced a relatively high expression of CTLA-4 in feline PBMC. Key words CD28 CTLA-4 FIV infection PBMC competitive PCR. Introduction CD28 a T cell-specific glycoprotein is expressed as a homodimer in most T lymphocytes 2 31 . CD28 has also been identified as the major co-receptor for binding B7-1 15 . It is known that the interaction of CD28 with B7 ligands in humans and mice provides a costimulatory signal inducing T cell proliferation IL-2 production and cytotoxicity 3 14 24 27 . CD28 is expressed in approximately 95 of CD4 and 70 of CD8 human T cells 7 . Corresponding author Phone .
