Buddle Bryce M, Wards Barry J, Aldwell Frank E, Collins Desmond M, de Lisle Geoffrey W
AgResearch, Wallaceville Animal Research Centre, P.O. Box 40063, Upper Hutt, New Zealand.
Vaccine. 2002 Jan 15;20(7-8):1126-33. doi: 10.1016/s0264-410x(01)00436-4.
Bacille Calmette-Guerin (BCG) is the world's most widely used vaccine, but there are concerns that it provides little protection against pulmonary tuberculosis of humans in countries that have a high prevalence of environmental mycobacteria. Experiments in cattle provide a model to investigate this situation and to develop an improved tuberculosis vaccine. In the third of a series of BCG vaccination trials, calves had high interferon-gamma (IFN-gamma) responses to purified protein derivative (PPD) from Mycobacterium avium prior to vaccination, indicating that infection with environmental mycobacteria had occurred. The calves vaccinated with BCG had minimal protection against an experimental intratracheal challenge with virulent Mycobacterium bovis. In comparison, calves vaccinated with either of two newly-derived attenuated M. bovis strains had significantly better but not complete protection against the development of tuberculous lesions compared to both BCG-vaccinated and non-vaccinated animals. Vaccination with the newly-derived attenuated M. bovis strains induced strong IFN-gamma and interleukin-2 (IL-2) responses to PPD from M. bovis at 2 weeks after vaccination, while BCG vaccination induced only a weak response at this time. In association with the previous two trials, the results suggest that sensitisation of the calves to environmental mycobacteria adversely affected subsequent protective efficacy of BCG. However, the results of vaccination with the other two attenuated M. bovis strains indicated that improved tuberculosis vaccines could be developed for such sensitised animals.
卡介苗（BCG）是世界上使用最广泛的疫苗，但在环境分枝杆菌高发的国家，人们担心它对人类肺结核的保护作用甚微。牛的实验为研究这种情况和开发改进的结核病疫苗提供了一个模型。在一系列卡介苗接种试验的第三次试验中，小牛在接种前对鸟分枝杆菌的纯化蛋白衍生物（PPD）有较高的干扰素-γ（IFN-γ）反应，表明已发生环境分枝杆菌感染。接种卡介苗的小牛对强毒牛分枝杆菌的实验性气管内攻击的保护作用极小。相比之下，与接种卡介苗和未接种疫苗的动物相比，接种两种新衍生的减毒牛分枝杆菌菌株之一的小牛对结核病变的发展有明显更好但不完全的保护作用。接种新衍生的减毒牛分枝杆菌菌株在接种后2周对牛分枝杆菌的PPD诱导了强烈的IFN-γ和白细胞介素-2（IL-2）反应，而此时卡介苗接种仅诱导了微弱的反应。结合前两次试验，结果表明小牛对环境分枝杆菌的致敏对卡介苗随后的保护效果产生了不利影响。然而，用其他两种减毒牛分枝杆菌菌株接种的结果表明，可以为这种致敏动物开发改进的结核病疫苗。
