Early detection of the lytic LMP-1 protein in EBV-infected B-cells suggests its presence in the virion.
Early detection of the lytic LMP-1 protein in EBV-infected B-cells suggests its presence in the virion.
复制标题
在 EBV 感染的 B 细胞中早期检测到裂解性 LMP-1 蛋白表明其存在于病毒颗粒中。
DOI：
10.1006/viro.1997.8638
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Martin,JM
中科院分区：
文献类型：
--
作者：
Erickson,KD;Martin,JM
Epstein-Barr 病毒 (EBV) 阳性 B958 细胞系表达由 BNLF-1 开放阅读框编码的两种相关膜蛋白。一种蛋白质 (LMP-1) 已被证明对于 EBV 的生长转化特性至关重要。第二种蛋白（裂解性 LMP-1）是 LMP-1 的氨基末端截短形式，其表达与 EBV 裂解周期的诱导相关。我们研究了 EBV 阴性 B 淋巴瘤细胞系 BJAB 感染后立即 LMP-1 全长和裂解形式的表达。在用来自未诱导的或十四烷酰佛波醇乙酸酯和丁酸钠诱导的 B958 细胞的病毒感染后的早期（添加病毒后几分钟内），仅裂解性 LMP-1 蛋白存在于 BJAB 细胞中。感染后 48 小时，裂解性 LMP-1 蛋白水平开始下降，而全长 LMP-1 水平在感染后 24 至 48 小时之间增加，然后保持恒定。受感染细胞中裂解性 LMP-1 蛋白的存在与蛋白合成和病毒内化无关。我们还发现，在感染 EBV HH514 株后（添加病毒后 3 小时内）的 BJAB 细胞中，早期存在裂解性 LMP-1 蛋白，并且用十四烷酰佛波醇乙酸酯和丁酸钠处理的 HH514 细胞表达高水平的裂解性 LMP-1 和全长 LMP-1 蛋白。裂解性 LMP-1 蛋白在纯化的病毒颗粒制剂中富集，免疫电镜分析表明 EBV 病毒颗粒可以用抗 LMP-1 抗血清特异性标记。总之，这些结果与裂解性 LMP-1 蛋白存在于 EBV 病毒颗粒中并在感染后被携带到 B 细胞中的模型一致，并表明该蛋白在早期感染事件和/或 EBV 裂解周期中的作用。
The Epstein–Barr virus (EBV)-positive B958 cell line expresses two related membrane proteins encoded by BNLF-1 open reading frames. One protein (LMP-1) has been shown to be essential for the growth transforming properties of EBV. The second protein (the lytic LMP-1) is an amino-terminally truncated form of LMP-1 whose expression is associated with induction of EBV's lytic cycle. We have investigated the expression of full-length and lytic forms of LMP-1 immediately after infection of the EBV-negative, B-lymphoma cell line BJAB. Only the lytic LMP-1 protein is present in BJAB cells early (within minutes following addition of virus) after infection with virus derived from either uninduced or tetradecanoyl phorbol acetate and sodium butyrate-induced B958 cells. Lytic LMP-1 protein levels begin to decline by 48 hr after infection, whereas levels of full-length LMP-1 increase between 24 and 48 hr after infection and then remain constant. The presence of the lytic LMP-1 protein in infected cells is independent of both protein synthesis and virus internalization. We also find the lytic LMP-1 protein in BJAB cells early after infection (within 3 hr of addition of virus) with the HH514 strain of EBV, and HH514 cells treated with tetradecanoyl phorbol acetate and sodium butyrate, express high levels of both the lytic LMP-1 and full-length LMP-1 proteins. The lytic LMP-1 protein is enriched in purified virion preparations, and immunoelectron microscopic analysis indicates that EBV virions can be specifically labeled with anti-LMP-1 antisera. Together, these results are consistent with a model in which the lytic LMP-1 protein is present in the EBV virion and is carried into the B-cell upon infection and suggest a role for this protein in early infection events and/or in EBV's lytic cycle.