Wang C C, Rook G A
Department of Bacteriology, UCL Medical School, London, UK.
Immunology. 1998 Mar;93(3):307-13. doi: 10.1046/j.1365-2567.1998.00432.x.
Allergic disorders are mediated by T lymphocytes secreting T helper 2 (Th2) cytokines, interleukin-4 (IL-4) and interleukin-5 (IL-5), resulting in high levels of serum immunoglobulin E (IgE) and recruitment of eosinophils. One of the treatment strategies is to downregulate the Th2 component by inducing a T helper 1 (Th1) response to the relevant allergen, because Th1 and Th2 cytokines are thought to be mutually antagonistic. In this study, we examined the effects of Mycobacterium vaccae, a potent inducer of Th1 immunity, on allergic responses in a murine model. A single injection of M. vaccae into ovalbumin (OVA)-preimmunized BALB/c mice suppressed serum IgE over a wide dose range (10(7), 10(8) or 10(9) M. vaccae). Further experiments, using 10(7) M. vaccae injected twice, showed that this treatment inhibited not only serum IgE, but also the potential for ovalbumin-induced IL-5 production by spleen cells. This non-specific ability of a mycobacterium to decrease Th2 activity, even when not presented together with the allergen, is in agreement with recent epidemiological studies on the impact of bacillus Calmette-Guérin (BCG) vaccination, and of other potent Th1 stimuli, on the incidence of atopy. The suppression of serum IgE and allergen-specific IL-5 synthesis by M. vaccae suggest that this organism is likely to have clinical application in the immunotherapy of allergy.
过敏性疾病由分泌辅助性T细胞2（Th2）细胞因子、白细胞介素-4（IL-4）和白细胞介素-5（IL-5）的T淋巴细胞介导，导致血清免疫球蛋白E（IgE）水平升高和嗜酸性粒细胞募集。治疗策略之一是通过诱导对相关过敏原的辅助性T细胞1（Th1）反应来下调Th2成分，因为Th1和Th2细胞因子被认为相互拮抗。在本研究中，我们检测了强效Th1免疫诱导剂母牛分枝杆菌对小鼠模型过敏反应的影响。向预先用卵清蛋白（OVA）免疫的BALB/c小鼠单次注射母牛分枝杆菌，在很宽的剂量范围内（10⁷、10⁸或10⁹个母牛分枝杆菌）均可抑制血清IgE。进一步实验表明，使用10⁷个母牛分枝杆菌注射两次，这种治疗不仅抑制血清IgE，还抑制脾细胞产生卵清蛋白诱导的IL-5的潜力。即使不与过敏原同时存在，分枝杆菌降低Th2活性的这种非特异性能力与最近关于卡介苗（BCG）接种以及其他强效Th1刺激对特应性疾病发病率影响的流行病学研究结果一致。母牛分枝杆菌对血清IgE和过敏原特异性IL-5合成的抑制表明，这种微生物可能在过敏免疫治疗中有临床应用价值。
