Complete bovine leukemia virus (BLV) provirus is conserved in BLV-infected cattle throughout the course of B-cell lymphosarcoma development
Complete bovine leukemia virus (BLV) provirus is conserved in BLV-infected cattle throughout the course of B-cell lymphosarcoma development
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DOI：
10.1128/jvi.72.9.7569-7576.1998
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发表时间：
1998-09-01
影响因子：
5.4
通讯作者：
Aida, Y
中科院分区：
文献类型：
--
作者：
Tajima, S;Ikawa, Y;Aida, Y
牛白血病病毒（BLV）与人t细胞白血病病毒1型和2型（HTLV-1和HTLV-2）同属癌病毒亚家族。有缺陷的HTLV-1前病毒基因组在半数以上的成人t细胞白血病患者中被发现。我们已经在不同阶段的淋巴瘤动物的外周血淋巴细胞和肿瘤组织中鉴定了整合BLV前病毒的基因组结构。与SacI的基因组南方杂交，产生BLV原病毒DNA的两个主要片段，在所有23头淋巴瘤期的牛和7头BLV感染但健康的牛中，只产生了与全尺寸原病毒相对应的条带。引物位于长末端重复序列的长PCR清楚地表明，在所有27头淋巴瘤牛和19头感染但健康的牛中几乎保留了完整的原病毒。然而，除了与全尺寸原病毒相对应的PCR产物外，27只淋巴瘤动物中只有一只动物产生了比完整病毒短的片段。此外，当我们使用跨越整个BLV基因组的各种引物进行常规PCR以检测甚至很小的缺陷时，在所有40头BLV感染牛中产生的PCR产物特异性地覆盖了整个BLV基因组。因此，在整个疾病过程中，似乎每只动物至少保持了一个全长BLV原病毒基因组的拷贝，此外，在BLV感染的牛中，或大或小的原病毒基因组缺失可能是非常罕见的事件。
Bovine leukemia virus (BLV) and human T-celi leukemia virus types 1 and 2 (HTLV-1 and HTLV-2) belong to the same subfamily of oncoviruses. Defective HTLV-1 proviral genomes have been found in more than half of all patients with adult T-cell leukemia examined. We have characterized the genomic structure of integrated BLV proviruses in peripheral blood lymphocytes and tumor tissue taken from animals with lymphomas at various stages. Genomic Southern hybridization with SacI, which generates two major fragments of BLV proviral DNA, yielded only bands that corresponded to a full-size provirus in all of 23 cattle at the lymphoma stage and in 7 BLV-infected but healthy cattle. Long PCR with primers located in long terminal repeats clearly demonstrated that almost the complete provirus was retained in all of 27 cattle with lymphomas and in 19 infected but healthy cattle. However, in addition to a PCR product that corresponded to a full-size provirus, a fragment shorter than that of the complete virus was produced in only one of the 27 animals with lymphomas. Moreover, when we performed conventional PCR with a variety of primers that spanned the entire BLV genome to detect even small defects, PCR products were produced that specifically covered the entire BLV genome in all of the 40 BLV-infected cattle tested. Therefore, it appears` that at least one copy of the full-length BLV proviral genome was maintained in each animal throughout the course of the disease and, in addition, that either large or small deletions of proviral genomes may be very rare events in BLV-infected cattle.