Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK, Canada S7N 5E3.
Vaccine. 2013 Feb 27;31(10):1406-12. doi: 10.1016/j.vaccine.2012.12.055. Epub 2013 Jan 20.
Mycoplasma bovis is one of the most significant contributors to the bovine respiratory syndrome (BRD) that causes major losses in feedlot and dairy farms. Current experimental vaccines against M. bovis are ineffective and in some cases seem to enhance disease. Experimental infection with M. bovis induces a predominantly Th2 response and high levels of IgG1, which is an inferior opsonin and hence lacks protective capacity. In an attempt to induce a balanced (Th1/Th2) immune response, we have used CpG ODN 2007 as an adjuvant in a trial involving vaccination of cattle with M. bovis total extracts and/or membrane fractions and subsequent intranasal inoculation with an infective dose of M. bovis prepared from two different clinical isolates. Significant IgG1 serum responses were observed against both, extracts and fractions while IgG2 responses were significant against the extracts only. Proliferation of peripheral blood mononuclear cells (PBMC) after incubation with M. bovis cells was only observed in post-challenge samples of cattle vaccinated with both extracts and fractions but not in samples of cattle immunized with the membrane fractions alone. All groups showed transient weight losses and increased temperatures however, there were no significant differences in clinical parameters and survival rates between the groups.
牛支原体是引起牛呼吸道综合征（BRD）的主要病原体之一，给牧场和奶牛场造成了重大损失。目前针对牛支原体的实验性疫苗效果不佳，在某些情况下似乎还会加重疾病。牛支原体的实验性感染会引起主要的 Th2 反应和高水平的 IgG1，而 IgG1 是一种较差的调理素，因此缺乏保护能力。为了诱导平衡（Th1/Th2）的免疫反应，我们使用 CpG ODN 2007 作为佐剂，在一项涉及用牛支原体总提取物和/或膜部分对牛进行疫苗接种，并随后用来自两种不同临床分离株的感染剂量进行鼻内接种的试验中进行了尝试。针对提取物和部分都观察到了显著的 IgG1 血清反应，而 IgG2 反应仅针对提取物显著。在用牛支原体细胞孵育后，仅在接种了两种提取物和部分的牛的挑战后样本中观察到外周血单核细胞（PBMC）的增殖，但在单独免疫膜部分的牛的样本中未观察到。所有组均表现出短暂的体重减轻和体温升高，但在临床参数和存活率方面，各组之间没有显著差异。
