Herpesvirus Telomerase RNA (vTR) with a Mutated Template Sequence Abrogates Herpesvirus-Induced Lymphomagenesis
Herpesvirus Telomerase RNA (vTR) with a Mutated Template Sequence Abrogates Herpesvirus-Induced Lymphomagenesis
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DOI：
10.1371/journal.ppat.1002333
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发表时间：
2011-10-01
期刊：
影响因子：
6.7
通讯作者：
Jarosinski, Keith W.
中科院分区：
文献类型：
--
作者：
Kaufer, Benedikt B.;Arndt, Sina;Jarosinski, Keith W.
端粒酶逆转录酶(TERT)和端粒酶RNA(TR)是端粒酶的活性成分。在复合体中，tr为端粒增加端粒重复序列提供模板，端粒是线性染色体末端的保护性结构。模板区域发生突变的人类转录因子在体外可以抑制癌细胞的增殖。在这份报告中，我们研究了病毒编码的tr(Vtr)模板突变在体内疱疹病毒诱导的肿瘤形成中的作用。为此，我们使用致癌的禽疱疹病毒马立克氏病病毒(MDV)作为淋巴肿大的自然病毒宿主模型。我们通过两步Red诱变获得了重组MDV，其中VTR模板序列从AATCCCAATC突变为ATATATATAT(VAU5)。含有模板突变的重组病毒在体外的复制动力学与亲本病毒和突变病毒相当。然而，VTR模板序列的突变完全消除了病毒在体内诱导的肿瘤形成，尽管病毒能够进行低水平的裂解复制。为了证实肿瘤的存在取决于端粒酶复合体中突变VTR的存在，在vAU5中引入了第二个突变，该突变针对的是P6.1茎环，这是VTR-TERT相互作用所必需的保守区域。端粒酶复合体中缺少VTR-AU5可恢复病毒诱导的淋巴瘤的形成。为了验证vAU5弱毒疫苗是否可以作为MDV的有效疫苗，我们进行了疫苗攻毒试验，结果表明，vAU5疫苗能完全保护雏鸡免受强毒的攻击。综上所述，我们的结果表明，1)VTR模板序列的突变可以完全消除病毒诱导的肿瘤形成，可能是通过抑制癌细胞的增殖，以及2)这一策略可以用于产生针对病毒诱导的淋巴瘤的新的候选疫苗。
Telomerase reverse transcriptase (TERT) and telomerase RNA (TR) represent the enzymatically active components of telomerase. In the complex, TR provides the template for the addition of telomeric repeats to telomeres, a protective structure at the end of linear chromosomes. Human TR with a mutation in the template region has been previously shown to inhibit proliferation of cancer cells in vitro. In this report, we examined the effects of a mutation in the template of a virus encoded TR (vTR) on herpesvirus-induced tumorigenesis in vivo. For this purpose, we used the oncogenic avian herpesvirus Marek's disease virus (MDV) as a natural virus-host model for lymphomagenesis. We generated recombinant MDV in which the vTR template sequence was mutated from AATCCCAATC to ATATATATAT (vAU5) by two-step Red-mediated mutagenesis. Recombinant viruses harboring the template mutation replicated with kinetics comparable to parental and revertant viruses in vitro. However, mutation of the vTR template sequence completely abrogated virus-induced tumor formation in vivo, although the virus was able to undergo low-level lytic replication. To confirm that the absence of tumors was dependent on the presence of mutant vTR in the telomerase complex, a second mutation was introduced in vAU5 that targeted the P6.1 stem loop, a conserved region essential for vTR-TERT interaction. Absence of vTR-AU5 from the telomerase complex restored virus-induced lymphoma formation. To test if the attenuated vAU5 could be used as an effective vaccine against MDV, we performed vaccination-challenge studies and determined that vaccination with vAU5 completely protected chickens from lethal challenge with highly virulent MDV. Taken together, our results demonstrate 1) that mutation of the vTR template sequence can completely abrogate virus-induced tumorigenesis, likely by the inhibition of cancer cell proliferation, and 2) that this strategy could be used to generate novel vaccine candidates against virus-induced lymphoma.