Jacobs R M, Song Z, Poon H, Heeney J L, Taylor J A, Jefferson B, Vernau W, Valli V E
Department of Pathology, Ontario Veterinary College, University of Guelph.
Can J Vet Res. 1992 Oct;56(4):339-48.
Twenty-seven cattle with lymphoma and 46 cows from a known bovine leukemia virus (BLV)-infected herd were tested for anti-BLV antibody by the agar gel immunodiffusion (AGID) test and an enzyme-linked immunosorbent assay (ELISA). The polymerase chain reaction (PCR) and Southern hybridization were used to detect BLV provirus in the tumor DNA of the 27 cattle with lymphoma. The PCR was used to detect BLV provirus in the peripheral blood mononuclear cell DNA of the 46 normal known-exposed cattle. Two presumed false negative AGID test results compared to ELISA were found. Of ten cattle three years of age or less with "sporadic" forms of lymphoma, four had BLV provirus in tumor DNA, detectable by PCR. In two of these four, BLV provirus was clonally integrated based on digestion of tumor DNA with restriction enzymes followed by Southern hybridization. The BLV provirus was not detected by PCR in 5 of 17 cattle with "enzootic" lymphoma and two of these five were seronegative. Among normal BLV-exposed cows, 6.5% (3 of 46) were serologically positive and PCR negative; serologically negative and PCR positive cows occurred with the same frequency. Serological and PCR test results, when considered in all cattle (n = 73), had a concordance rate of 83.6%. Discordant test results occurred with approximately equal frequency between serologically positive and PCR negative (7 of 73, 9.6%) and serologically negative and PCR positive (5 of 73, 6.8%) groups. These data suggest that the role of BLV in some "sporadic" bovine lymphomas, previously unassociated with BLV, should be reexamined. The BLV provirus was not demonstrable in the tumor DNA from five adult cattle with lymphoma, suggesting that BLV may not be the etiological agent in all adult bovine lymphomas. The findings of persistently seronegative PCR positive and seropositive PCR negative cattle indicate that further work is needed to more fully understand the host-virus interaction. Present serological screening methods may not have sufficient sensitivity for determining BLV status in some circumstances.
对27头患有淋巴瘤的牛以及来自已知感染牛白血病病毒（BLV）牛群的46头母牛，采用琼脂凝胶免疫扩散试验（AGID）和酶联免疫吸附测定（ELISA）检测抗BLV抗体。利用聚合酶链反应（PCR）和Southern杂交技术，检测27头患有淋巴瘤的牛的肿瘤DNA中的BLV前病毒。用PCR检测46头已知暴露的正常牛外周血单个核细胞DNA中的BLV前病毒。发现与ELISA相比有两个AGID试验结果可能为假阴性。在10头3岁及以下患有“散发”型淋巴瘤的牛中，4头的肿瘤DNA中有可通过PCR检测到的BLV前病毒。在这4头中的2头中，基于用限制性内切酶消化肿瘤DNA后进行Southern杂交，发现BLV前病毒是克隆整合的。在17头患有“地方流行性”淋巴瘤的牛中，5头通过PCR未检测到BLV前病毒，其中2头血清学呈阴性。在正常暴露于BLV的母牛中，6.5%（46头中的3头）血清学呈阳性但PCR呈阴性；血清学呈阴性但PCR呈阳性的母牛出现频率相同。在所有牛（n = 73）中考虑血清学和PCR检测结果时，一致性率为83.6%。血清学呈阳性但PCR呈阴性（73头中的7头，9.6%）和血清学呈阴性但PCR呈阳性（73头中的5头，6.8%）组之间不一致的检测结果出现频率大致相等。这些数据表明，BLV在一些以前与BLV无关的 “散发” 型牛淋巴瘤中的作用应重新审视。在5头患有淋巴瘤的成年牛的肿瘤DNA中未检测到BLV前病毒，这表明BLV可能不是所有成年牛淋巴瘤的病原体。持续出现血清学阴性但PCR阳性和血清学阳性但PCR阴性的牛的结果表明，需要进一步开展工作以更全面地了解宿主 - 病毒相互作用。目前的血清学筛查方法在某些情况下可能没有足够的灵敏度来确定BLV状态。
