Bautista E M, Molitor T W
Department of Clinical and Population Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, USA.
Viral Immunol. 1997;10(2):83-94. doi: 10.1089/vim.1997.10.83.
Cell-mediated immunity has been demonstrated to be a necessary component of immunity against viral infection. Methods to detect T-cell mediated immune responses to porcine reproductive and respiratory syndrome virus (PRRSV) infection were established both in vitro as lymphocyte proliferation and in vivo as delayed-type hypersensitivity response (DTH). Optimal conditions for detection of lymphocyte proliferation were determined by testing different antigen concentrations and various stimulation periods. The proliferation response to PRRSV was antigen-specific and dose-dependent. The kinetics of the T-cell proliferation response to PRRSV were analyzed after primary and secondary exposure to virus. Lymphocyte proliferation was first detected at four weeks post-infection (PI), peaked at 7 weeks PI, and declined after 11 weeks PI. The secondary response increased in magnitude. Experiments with blocking antibodies to porcine leukocyte antigens demonstrated that CD4+ T-cells were the major effector cells in the proliferation response. The in vivo response to PRRSV was shown by detection of a dose-dependent DTH reaction in infected pigs after intradermal challenge with UV-inactivated virus. These results demonstrate that pigs generate specific T-cell responses on PRRSV infection and provide a foundation for studying their role in protection.
细胞介导的免疫已被证明是抵抗病毒感染免疫的必要组成部分。检测猪繁殖与呼吸综合征病毒（PRRSV）感染的T细胞介导免疫反应的方法已在体外作为淋巴细胞增殖以及在体内作为迟发型超敏反应（DTH）得以确立。通过测试不同抗原浓度和不同刺激时间来确定检测淋巴细胞增殖的最佳条件。对PRRSV的增殖反应具有抗原特异性且呈剂量依赖性。在初次和二次接触病毒后分析了T细胞对PRRSV增殖反应的动力学。淋巴细胞增殖在感染后4周首次检测到，在感染后7周达到峰值，并在感染后11周后下降。二次反应的幅度增加。用针对猪白细胞抗原的阻断抗体进行的实验表明，CD4 + T细胞是增殖反应中的主要效应细胞。通过在用紫外线灭活病毒进行皮内攻击后检测感染猪中剂量依赖性的DTH反应来显示对PRRSV的体内反应。这些结果表明猪在PRRSV感染时产生特异性T细胞反应，并为研究它们在保护中的作用提供了基础。
