Begara I, Luján L, Collie D D, Miller H R, Watt N J
Department of Veterinary Clinical Studies, Royal (Dick) School of Veterinary Studies, University of Edinburgh Veterinary Field Station, Easter Bush, UK.
Vet Immunol Immunopathol. 1996 Dec;55(1-3):115-26. doi: 10.1016/s0165-2427(96)05623-1.
A model of experimental infection with EV1, a British isolate of maedi-visna virus (MVV), has been developed. Twelve male Texel sheep were allocated to three groups and inoculated by the respiratory route with different inocula. Six of the animals received 10(7.2) tissue culture infective dose (TCID50) of MVV EV1 strain. Two sheep were inoculated with the same dose of heat inactivated MVV EV1 strain. An additional group of four sheep was sham-inoculated with identically prepared virus-free culture media. Experimental infection was followed for 16 weeks. Prior to inoculation, routine haematology, bronchoalveolar lavage (BAL) and flow cytometric analysis of bronchoalveolar lavage fluid (BALF) lymphocytes were performed in all animals to provide baseline parameters. Flow cytometric analysis of BALF lymphocytes and differential BALF cell counts were performed. Precipitating antibodies to MVV developed in all MVV-inoculated animals during the first 4 weeks post-inoculation, while the rest remained seronegative to MVV. MVV-infected animals had significantly decreased (P < 0.05) percentages of macrophages and significantly increased (P < 0.05) percentages of lymphocytes in BALF 4 weeks post-inoculation. Phenotypic changes in BALF T lymphocytes from MVV-inoculated animals, compared with the other two groups, showed significantly decreased (P < 0.05) percentages of CD4+ and gamma delta + T lymphocytes, significantly increased (P < 0.05) percentages of CD8+ lymphocytes and significant inversion (P < 0.05) of the CD4+/CD8+ ratio at different sampling times, but between 2 and 12 weeks post-inoculation. These findings indicate that during experimental MVV-infection an early, short-term cellular reaction occurs in the lung, that is characterised by T lymphocyte phenotypic changes that are very similar, if not identical, to those observed in natural MVV infection.
已建立了一种用梅迪 - 维斯纳病毒（MVV）英国分离株EV1进行实验性感染的模型。将12只雄性特克塞尔羊分为三组，通过呼吸道接种不同的接种物。其中6只动物接种10(7.2) 组织培养感染剂量（TCID50）的MVV EV1株。2只羊接种相同剂量的热灭活MVV EV1株。另外一组4只羊用同样制备的无病毒培养基进行假接种。实验感染持续16周。在接种前，对所有动物进行常规血液学检查、支气管肺泡灌洗（BAL）以及支气管肺泡灌洗液（BALF）淋巴细胞的流式细胞术分析，以提供基线参数。进行了BALF淋巴细胞的流式细胞术分析和BALF细胞分类计数。接种MVV的所有动物在接种后第1个4周内产生了针对MVV的沉淀抗体，而其余动物对MVV仍呈血清阴性。接种MVV的动物在接种后4周时，BALF中巨噬细胞百分比显著降低（P < 0.０5），淋巴细胞百分比显著升高（P < 0.０5）。与其他两组相比，接种MVV动物的BALF T淋巴细胞表型变化显示，在接种后2至12周的不同采样时间，CD4 +和γδ + T淋巴细胞百分比显著降低（P < 0.０5），CD8 +淋巴细胞百分比显著升高（P < 0.０5），CD4 + / CD8 +比值显著倒置（P < 0.０5）。这些发现表明，在实验性MVV感染期间，肺中会发生早期、短期的细胞反应，其特征是T淋巴细胞表型变化，与自然MVV感染中观察到的变化非常相似（如果不是完全相同的话）。
