Nakamura R M
Department of Bacteriology, National Institute of Health, Tokyo, Japan.
Kekkaku. 1993 May;68(5):361-5.
The protective immunity against virulent mycobacteria is induced by Mycobacterium bovis BCG in mice. It was found that a preceding infection with a strain of atypical mycobacteria, M. avium Mino, suppresses the BCG-induced protective immunity. In the present study, protective immunity was judged by the extended survival time after the challenge with virulent mycobacteria, M. bovis Ravenel. C57BL/10 mice receiving BCG vaccination with 10(7) live bacilli sc showed prolonged survival after 10(6) injection with M. bovis Ravenel iv. Infection of these mice with M. avium Mino, 10(6) iv, 2 weeks before BCG vaccination shortened the survival time significantly. This suppression of protective immunity was caused by CD8+ T cells. CD4+ T cells also had a weak suppressive effect on the protective immunity, but was not the main population of suppressor T cells. Thus, it was confirmed that atypical mycobacterial infection produces CD8+ suppressor T cells which inhibit both protective immunity and delayed-type hypersensitivity induced by BCG.
牛分枝杆菌卡介苗（Mycobacterium bovis BCG）可在小鼠体内诱导产生针对强毒力分枝杆菌的保护性免疫。研究发现，先前感染非典型分枝杆菌鸟型分枝杆菌美浓株（Mycobacterium avium Mino）会抑制卡介苗诱导的保护性免疫。在本研究中，通过强毒力分枝杆菌牛分枝杆菌拉韦内尔株（Mycobacterium bovis Ravenel）攻击后存活时间的延长来判断保护性免疫。接受10⁷ 活卡介苗皮下接种的C57BL/10小鼠在静脉注射10⁶ 牛分枝杆菌拉韦内尔株后存活时间延长。在卡介苗接种前2周静脉注射10⁶ 鸟型分枝杆菌美浓株感染这些小鼠，显著缩短了存活时间。这种保护性免疫的抑制是由CD8⁺ T细胞引起的。CD4⁺ T细胞对保护性免疫也有较弱的抑制作用，但不是抑制性T细胞的主要群体。因此，证实非典型分枝杆菌感染产生CD8⁺ 抑制性T细胞，其抑制卡介苗诱导的保护性免疫和迟发型超敏反应。
