Hook S, Griffin F, Mackintosh C, Buchan G
Microbiology Department, University of Otago, Dunedin, New Zealand.
Immunology. 1996 Jun;88(2):269-74. doi: 10.1111/j.1365-2567.1996.tb00014.x.
This study examines the expression of mRNA for the Th2 cytokine, interleukin-4 (IL-4). Peripheral blood mononuclear cells from deer infected with Mycobacterium bovis or vaccinated with live or killed M. bovis bacillus Calmette-Guérin (BCG) were cultured with mycobacterial antigens. IL-4 mRNA production was assayed using the polymerase chain reaction. Elevated levels of IL-4 mRNA were detected in response to at least one antigen preparation in all animals infected with M. bovis as compared with none of the non-infected control animals. After a primary immunization, elevated levels of IL-4 mRNA were detected in only a proportion of vaccinated animals and this did not correlate with whether the vaccine was live BCG or killed BCG in oil. After boosting, all the animals vaccinated with killed BCG in oil exhibited elevated IL-4 mRNA production whereas none of the animals vaccinated with live BCG showed elevated levels. The data suggest that IL-4 is turned off during the immune response to live BCG, that boosting of low-dose live BCG vaccine may be required to 'imprint' this signal and that this may be important in the development of protective immunity to tuberculosis. Killed BCG in adjuvant is not protective and as with experimental infection with virulent M. bovis it failed to switch off the IL-4 response. IL-4 may be useful as a diagnostic tool and as an in vitro marker of vaccine efficacy.
本研究检测了Th2细胞因子白细胞介素-4（IL-4）的mRNA表达。用分枝杆菌抗原培养来自感染牛分枝杆菌或接种活卡介苗或灭活卡介苗（BCG）的鹿的外周血单个核细胞。使用聚合酶链反应检测IL-4 mRNA的产生。与未感染的对照动物相比，在所有感染牛分枝杆菌的动物中，至少对一种抗原制剂有反应时检测到IL-4 mRNA水平升高。初次免疫后，仅在一部分接种疫苗的动物中检测到IL-4 mRNA水平升高，这与疫苗是活卡介苗还是油剂灭活卡介苗无关。加强免疫后，所有接种油剂灭活卡介苗的动物IL-4 mRNA产生均升高，而接种活卡介苗的动物均未出现升高。数据表明，在对活卡介苗的免疫反应中IL-4被关闭，可能需要加强低剂量活卡介苗疫苗以“印记”该信号，这在结核病保护性免疫的发展中可能很重要。佐剂中的灭活卡介苗无保护作用，与强毒牛分枝杆菌的实验感染一样，它未能关闭IL-4反应。IL-4可能作为一种诊断工具以及疫苗效力的体外标志物。
