Nakatsuchi Ayumi, Bao Aronggaowa, Watanuki Sonoko, Matsuura Ryosuke, Borjigin Liushiqi, Bai Lanlan, Kuroda Maho, Matsumoto Yasunobu, Kohara Junko, Aida Yoko
Institute of Animal Health, JA Zen-Noh (National Federation of Agricultural Cooperative Associations), Sakura, Japan.
Laboratory of Global Infectious Diseases Control Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
Front Vet Sci. 2022 Nov 25;9:1038101. doi: 10.3389/fvets.2022.1038101. eCollection 2022.
Bovine leukemia virus (BLV) belongs to the family and is a causative agent for enzootic bovine leucosis, the most common neoplastic disease affecting cattle worldwide. BLV proviral load (PVL) is associated with disease progression and transmission risk but requires blood collection and quantitative PCR testing. Anti-BLV antibodies in whey have been used as a diagnostic tool for BLV infection; however, quantitative utilization has not been fully investigated. Furthermore, bovine leukocyte antigen ()- is a polymorphic gene associated with BLV infectivity and PVL, but its effect on anti-BLV antibody levels in whey from BLV infected dams is unknown. Therefore, we aimed to investigate whether it is possible to correctly predict PVL in the blood and milk based on the amount of anti-BLV antibodies in milk, and whether the alleles associate with the amount of anti-BLV antibodies in milk.
We examined whey from 442 dams from 11 different dairy farms located in 6 prefectures in Japan, including susceptible dams carrying at least one -3 or allele related with high PVL, resistant dams carrying at least one , , or allele related with low PVL, and neutral dams carrying other alleles.
First, our results provided compelling evidence that anti-BLV antibody levels in whey were positively correlated with the anti-BLV antibody levels in serum and with BLV PVL in blood and milk, indicating the possibility of estimating BLV PVL in blood and milk by measuring anti-BLV antibody levels in whey. Thus, our results showed that antibody titers in milk might be effective for estimating BLV transmission risk and disease progression in the field. Second, we demonstrated that anti-BLV antibody levels in whey from BLV resistant dams were significantly lower than those from susceptible and neutral dams.
This is the first report suggesting that the polymorphism affects anti-BLV antibody levels in whey from BLV-infected dams. Taken together, our results suggested that anti-BLV antibody levels in whey, measured by enzyme-linked immunosorbent assay, may be a useful marker to diagnose the risk of BLV infection and estimate PVL in blood and milk.
牛白血病病毒（BLV）属于 科，是引起地方流行性牛白血病的病原体，这是全球影响牛群的最常见肿瘤性疾病。BLV前病毒载量（PVL）与疾病进展和传播风险相关，但需要采集血液并进行定量PCR检测。乳清中的抗BLV抗体已被用作BLV感染的诊断工具；然而，其定量应用尚未得到充分研究。此外，牛白细胞抗原（）- 是一个与BLV感染性和PVL相关的多态性基因，但其对感染BLV的母畜乳清中抗BLV抗体水平的影响尚不清楚。因此，我们旨在研究是否有可能根据乳中抗BLV抗体的量正确预测血液和乳汁中的PVL，以及 等位基因是否与乳中抗BLV抗体的量相关。
我们检测了来自日本6个县11个不同奶牛场的442头母畜的乳清，包括携带至少一个与高PVL相关的 -3 或 等位基因的易感母畜、携带至少一个与低PVL相关的 、 或 等位基因的抗性母畜，以及携带其他等位基因的中性母畜。
首先，我们的结果提供了有力证据，表明乳清中的抗BLV抗体水平与血清中的抗BLV抗体水平以及血液和乳汁中的BLV PVL呈正相关，这表明通过测量乳清中的抗BLV抗体水平来估计血液和乳汁中的BLV PVL是可能的。因此，我们的结果表明，乳中的抗体滴度可能有助于估计田间BLV的传播风险和疾病进展。其次，我们证明了BLV抗性母畜乳清中的抗BLV抗体水平显著低于易感和中性母畜。
这是第一份表明 多态性影响感染BLV的母畜乳清中抗BLV抗体水平的报告。综上所述，我们的结果表明，通过酶联免疫吸附测定法测量的乳清中的抗BLV抗体水平可能是诊断BLV感染风险和估计血液和乳汁中PVL的有用标志物。
