TRANSCRIPTIONAL ACTIVATION OF BOVINE LEUKEMIA-VIRUS IN BLOOD-CELLS FROM EXPERIMENTALLY INFECTED, ASYMPTOMATIC SHEEP WITH LATENT INFECTIONS
TRANSCRIPTIONAL ACTIVATION OF BOVINE LEUKEMIA-VIRUS IN BLOOD-CELLS FROM EXPERIMENTALLY INFECTED, ASYMPTOMATIC SHEEP WITH LATENT INFECTIONS
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DOI：
10.1128/jvi.63.5.2099-2107.1989
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发表时间：
1989-05-01
影响因子：
5.4
通讯作者：
RADKE, K
中科院分区：
文献类型：
--
作者：
LAGARIAS, DM;RADKE, K
牛白血病病毒（BLV）感染的特点是潜伏期长，之后一些人发展为B细胞肿瘤。BLV和相关病毒在初始感染和随后的肿瘤发生之间的潜伏期期间的行为知之甚少。我们用原位杂交技术检测了实验感染的无症状潜伏感染绵羊外周血单个核细胞中BLV的转录本。在尽可能快地从循环血液中分离的大多数外周血细胞中没有发现病毒RNA，但它存在于罕见的细胞中。BLV RNA转录物在血细胞置于培养物中后几小时内以双相方式增加。暴露于胎牛血清被确定为这种转录激活的主要原因，其发生在不到1/1，000的细胞中。已知多克隆激活免疫细胞的试剂在8小时内导致含有BLV RNA的细胞数量进一步增加。在某些情况下，单个细胞内的病毒转录本数量也增加。因此，BLV在血液中循环的大多数静息淋巴细胞中不能检测到表达，但其转录被胎牛血清的组分激活，并且可以被模拟免疫细胞激活的分子增强。这种激活可能发生在免疫应答期间的淋巴组织中，可能导致病毒调节蛋白的合成，这些蛋白被认为通过宿主细胞基因启动肿瘤发生。
Infection by bovine leukemia virus (BLV) is characterized by a long latency period, after which some individuals develop B-cell tumors. The behavior of BLV and related retorviruses during the latency period between initial infection and subsequent tumorigenesis is poorly understood. We used in situ hybridizatio to detect BLV transcripts in individual peripheral blood mononuclear cells from experimentally infected, asymptomatic sheep with latent infections. Viral RNA was not found in most peripheral blood cells that had been isolated as rapidly as possible from circulating blood, but it was present in rare cells. BLV RNA transcripts increased in a biphasic manner within a few hours after the blood cells were placed in culture. Exposure to fetal bovine serum was identified as the principal cause of this transcriptional activation, which occurred in fewer than 1 in 1,000 cells. Agents known to activate immune cells polyclonally caused a further increase in the number of cells containing BLV RNA within 8 h. In some cases, the numbers of viral transcripts within individual cells also increased. Thus, BLV is not detectably expressed in most resting lymphocytes circulating in the blood, but its transcription is activated by components of fetal bovine serum and can be augmented by molecules that mimic activation of immune cells. This activation, which might occur in lymphoid tissues during an immune response, may lead to the synthesis of viral regulatory proteins that are thought to initiate tumorigenesis through host cell genes.