Cherney T M, Schultz R D
Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706, USA.
Am J Vet Res. 1996 Jun;57(6):812-8.
To determine the bovine leukemia virus (BLV) antibody response and infectivity status in BLV-vaccinated cattle after challenge exposure with BLV-infected lymphocytes.
Steers were inoculated with vaccinia virus constructs expressing the gag, pol, and env genes of the BLV or the env gene only of the BLV genome, then challenge exposed with BLV-infected lymphocytes. The steers' BLV antibody and infectivity status was monitored.
Fifteen 8- to 9-month-old Holstein steers previously determined to be BLV antibody and BLV negative.
1 month after second after inoculation, steers were challenge exposed with 10(6) BLV-infected lymphocytes from a highly infective BLV-positive cow. Serum and blood lymphocytes were obtained regularly for 6 months. The agar gel immunodiffusion assay, ELISA, and serum neutralization assay were used to detect BLV antibody in serum of steers. The sheep infectivity and syncytium-forming assays were used to determine the viral status of the steers.
Differences were seen in antibody responses between the BLV-vaccinated and non-BLV-vaccinated control groups. All cattle were susceptible to infection when challenge exposed with BLV-infected lymphocytes.
Despite the enhanced immune response in the BLV-vaccinated cattle after challenge exposure, none of the BLV-vaccinated cattle was protected from BLV infection.
Vaccination is not an effective way to protect cattle from BLV infection.
确定经牛白血病病毒（BLV）疫苗接种的牛在接触感染BLV的淋巴细胞后其抗体反应和感染状态。
给公牛接种表达BLV的gag、pol和env基因或仅表达BLV基因组env基因的痘苗病毒构建体，然后用感染BLV的淋巴细胞进行攻击暴露。监测公牛的BLV抗体和感染状态。
15头8至9月龄的荷斯坦公牛，之前确定为BLV抗体和BLV阴性。
在第二次接种后1个月，用来自一头高传染性BLV阳性母牛的10(6)个感染BLV的淋巴细胞对公牛进行攻击暴露。定期采集血清和血液淋巴细胞，持续6个月。采用琼脂凝胶免疫扩散试验、ELISA和血清中和试验检测公牛血清中的BLV抗体。采用绵羊感染性试验和成细胞试验确定公牛的病毒状态。
接种BLV疫苗的组和未接种BLV疫苗的对照组之间在抗体反应上存在差异。当用感染BLV的淋巴细胞进行攻击暴露时，所有牛都易受感染。
尽管接种BLV疫苗的牛在攻击暴露后免疫反应增强，但没有一头接种BLV疫苗的牛能免受BLV感染。
接种疫苗不是保护牛免受BLV感染的有效方法。
