Tuyển tập các báo cáo nghiên cứu khoa học quốc tế về bệnh thú y đề tài: Unique features of bovine lymphocytes exposed to a staphylococcal enterotoxin | J. Vet. Set. 2006 7 3 233-239 JOURNAL OF Veterinary Science Unique features of bovine lymphocytes exposed to a staphylococcal enterotoxin XT XX TV 1 1 XT X- XX 7 2 11 A XI 1 1 2 T 3 X X y XI 3 Yong Ho Park Sang Un Lee Witold A. Ferens Sparrow Samuels William c. Davis Lawrence K. Fox Jong Sam Ahn Keun Seok Seo2 Byoung Sun Chang1 5 Sun Young Hwang1 Gregory A. Bohach2 Department of Microbiology College of Veterinary Medicine Seoul National University Seoul 151-742 Korea 2Department of Microbiology Molecular Biology and Biochemistry University of Idaho Moscow Idaho 83844 USA 3Department of Veterinary Microbiology and Pathology Washington State University Pullman WA 99164 USA Department of Pathology and Microbiology University of Nebraska Medical Center Omaha NE 68198 USA 5Animal Health Research LG Life Sciences Ltd. Daejeon 305-380 Korea We previously demonstrated that stimulation of bovine peripheral blood mononuclear cells PBMCs with staphylococcal enterotoxin c SEC led to an inversion of the c 1 4 C 1 8 T cell ratio and generation of an atypical CD8 T cell subpopulation expressing CD26. In the present study we examined T cell apoptosis and proliferation profiles of PBMC subpopulations in cultures stimulated with SEC. Unlike when stimulated with concanavalin A nucleic acid synthesis in bovine PBMC cultures stimulated with SEC was low during the first four days but increased greatly on day 5. In contrast nucleic acid synthesis in human PBMC cultures stimulated with SEC increased continuously. To investigate the mechanism of delayed bovine T cell proliferation various cell phenotypes were monitored. The inversion of the bovine CD4 CD8 T cell ratio in PBMC cultures stimulated by SEC was associated with higher proliferation and lower apoptosis of CD8 T cells compared to Cl 4 T cells. The mRNA levels for interleukin IL -4 and IL-13 were sustained over 4 days but IL-12 inRNA levels dropped to background on day 2. These data suggest that SEC induces a prolonged .