Golas Gavin, Park Byung S, Wong Scott W
Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, USA.
Biostatistics Shared Resource, Oregon Health & Science University, Knight Cancer Institute, Portland, Oregon, USA.
J Virol. 2025 Mar 18;99(3):e0192224. doi: 10.1128/jvi.01922-24. Epub 2025 Feb 25.
Rhesus macaque rhadinovirus (RRV) is a primate gamma-2 herpesvirus (rhadinovirus) closely related to Kaposi sarcoma-associated herpesvirus (KSHV), the human oncovirus that causes Kaposi sarcoma. Like other herpesviruses, KSHV and RRV encode numerous envelope glycoproteins involved in cell attachment, entry, as well as assembly and release of progeny virions from infected cells. Two glycoproteins postulated to form a complex and reported to be virus-neutralizing targets are glycoproteins M (gM) and N (gN). To investigate gM and gN in rhadinovirus infection, we utilized infectious and pathogenic bacterial artificial chromosomes (BAC). RRV BACmids with nonsense mutations introduced into gM or gN did not yield an infectious virus. However, when gM or gN of RRV were exchanged for gM or gN from KSHV, each of the KSHV-chimeric RRV BACmids restored virus replication and infectious spread. Interestingly, we also discovered that the substitution of KSHVgM into the RRV BACmid was associated with attenuation in viral spread, an effect that was not countered by a double-chimeric virus. In contrast, the substitution of RRV gN into a KSHV BACmid negatively affected the assembly of KSHV, independent of gM/gN complex formation. Therefore, here, we revealed that in KSHV and RRV, gM and gN are interchangeable, contribute to crucial functions for viral assembly and spread, and have evolved in a virus-specific manner. Although more research is needed to define the roles of gM and gN, our work establishes the first glycoprotein-chimeric viruses for KSHV and RRV, which can now be used to corroborate gM/gN as targets for a cancer vaccine.IMPORTANCEKaposi sarcoma (KS) is a human cancer caused by KSHV and is one of the most frequently occurring cancers in HIV/AIDS patients, as well as in regions where KSHV is endemic. In this report, we have constructed and authenticated the first KSHV glycoprotein-encoding chimeric viruses for evaluations in the RRV/rhesus macaque model and have also uncovered fundamental roles for the glycoproteins gM and gN. Our work is significant by successfully bridging the human-specific, species barrier that has previously restricted preclinical evaluations of the KSHV glycoproteins as vaccine targets . Although there is no KSHV-specific animal model that is widely used, these KSHV-chimeric viruses may be useful as tools to guide future vaccine design and strategy as vaccine candidates progress toward clinical trials.
恒河猴疱疹病毒（RRV）是一种灵长类γ-2疱疹病毒（嗜淋巴细胞疱疹病毒），与卡波西肉瘤相关疱疹病毒（KSHV）密切相关，KSHV是一种导致卡波西肉瘤的人类致癌病毒。与其他疱疹病毒一样，KSHV和RRV编码多种包膜糖蛋白，这些糖蛋白参与细胞附着、进入以及子代病毒粒子从感染细胞中的组装和释放。据推测，两种糖蛋白形成复合物并被报道为病毒中和靶点，即糖蛋白M（gM）和N（gN）。为了研究嗜淋巴细胞疱疹病毒感染中的gM和gN，我们利用了具有感染性和致病性的细菌人工染色体（BAC）。引入gM或gN无义突变的RRV BAC质粒不能产生感染性病毒。然而，当将RRV的gM或gN替换为KSHV的gM或gN时，每个KSHV嵌合RRV BAC质粒都恢复了病毒复制和感染性传播。有趣的是，我们还发现将KSHV gM替换到RRV BAC质粒中与病毒传播减弱有关，这种效应不会被双嵌合病毒抵消。相反，将RRV gN替换到KSHV BAC质粒中对KSHV的组装产生负面影响，这与gM/gN复合物的形成无关。因此，在这里，我们揭示了在KSHV和RRV中，gM和gN是可互换的，对病毒组装和传播的关键功能有贡献，并且是以病毒特异性方式进化的。尽管需要更多研究来确定gM和gN的作用，但我们的工作建立了首个针对KSHV和RRV的糖蛋白嵌合病毒，现在可用于证实gM/gN作为癌症疫苗的靶点。
重要性
卡波西肉瘤（KS）是一种由KSHV引起的人类癌症，是HIV/AIDS患者以及KSHV流行地区最常见的癌症之一。在本报告中，我们构建并验证了首个编码KSHV糖蛋白的嵌合病毒，用于在RRV/恒河猴模型中进行评估，并且还揭示了糖蛋白gM和gN的基本作用。我们的工作意义重大，成功跨越了以前限制将KSHV糖蛋白作为疫苗靶点进行临床前评估的人类特异性物种屏障。尽管没有广泛使用的KSHV特异性动物模型，但这些KSHV嵌合病毒可能作为工具，在候选疫苗向临床试验推进时指导未来的疫苗设计和策略。
