Marsden M J, Vaughan L M, Foster T J, Secombes C J
Department of Zoology, University of Aberdeen, United Kingdom.
Infect Immun. 1996 Sep;64(9):3863-9. doi: 10.1128/iai.64.9.3863-3869.1996.
We have previously described (L. M. Vaughan, P. R. Smith, and T. J. Foster, Infect. Immun. 61:2172-2181, 1993) the construction of a kanamycin-resistant aromatic-dependent mutant of Aeromonas salmonicida, the causative agent of furunculosis, and its use as a live vaccine. Here we describe the construction of an unmarked aroA deletion mutant and examine the nature and magnitude of immune responses in rainbow trout (Oncorhynchus mykiss) to this vaccine strain. Good proliferative and antibody responses were elicited by using a range of vaccine doses from 2 x 10(6) to 2 x 10(9) live bacteria per fish, and a clear vaccine dose effect was apparent. A significant positive effect of using live bacteria to prime for lymphocyte proliferation and antibody production was apparent. However, the problem of directly comparing the vaccine doses of live and killed bacterial preparations is discussed, since some replication of live bacteria in vivo is expected. Most importantly, the live vaccine preferentially stimulated enhanced T-cell responsiveness, as evidenced by significantly greater increases in T-cell proliferation than in B-cell proliferation, compared with responses by the respective cell populations from fish given a killed vaccine. The manner in which live vaccines elicit strong cell-mediated immune responses and the relevance to fish vaccine design are discussed.
我们之前已经描述过（L.M. 沃恩、P.R. 史密斯和T.J. 福斯特，《感染与免疫》61:2172 - 2181，1993）杀鲑气单胞菌（疖疮病的病原体）的卡那霉素抗性芳香族依赖型突变体的构建及其作为活疫苗的应用。在此我们描述无标记aroA缺失突变体的构建，并研究虹鳟（Oncorhynchus mykiss）对该疫苗株免疫反应的性质和强度。使用每尾鱼2×10⁶至2×10⁹个活细菌的一系列疫苗剂量可引发良好的增殖反应和抗体反应，且明显存在疫苗剂量效应。使用活细菌启动淋巴细胞增殖和抗体产生具有显著的积极效果。然而，由于预计活细菌在体内会有一定程度的复制，因此讨论了直接比较活细菌和灭活细菌制剂疫苗剂量的问题。最重要的是，与接种灭活疫苗的鱼的相应细胞群体的反应相比，活疫苗优先刺激增强的T细胞反应性，这表现为T细胞增殖的增加明显大于B细胞增殖。本文还讨论了活疫苗引发强烈细胞介导免疫反应的方式及其与鱼类疫苗设计的相关性。
