Second-Generation Live-Attenuated Candid#1 Vaccine Virus Resists Reversion and Protects against Lethal Junín Virus Infection in Guinea Pigs.
Second-Generation Live-Attenuated Candid#1 Vaccine Virus Resists Reversion and Protects against Lethal Junín Virus Infection in Guinea Pigs.
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第二代实时衰减坦率
DOI：
10.1128/jvi.00397-21
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发表时间：
2021
影响因子：
5.4
通讯作者：
Nunberg,JackH
中科院分区：
文献类型：
--
作者：
Gowen,BrianB;Hickerson,BradyT;York,Joanne;Westover,JonnaB;Sefing,EricJ;Bailey,KevinW;Wandersee,Luci;Nunberg,JackH
减毒活病毒疫苗在预防病毒性疾病方面非常有效，但存在残留毒力和致病性回复的内在风险。经典衍生的 Candid#1 病毒可保护阿根廷季节性野外工作人员免受胡宁病毒 (JUNV) 的人畜共患感染，但在美国未获批准，部分原因是减毒位点（GPC 包膜糖蛋白 GP2 亚基 427 位置上的苯丙氨酸至异亮氨酸取代）可能发生逆转。此前，我们证明了重组 Candid#1 (rCan) 在细胞培养物中的轻松逆转，并鉴定了减毒 I427 与 GPC 稳定信号肽 (SSP) 亚基中的二次 K33S 突变之间的上位相互作用，该突变对逆转施加了进化障碍。这种遗传障碍的严重性体现在我们屡次未能拯救假设的回复病毒。在这项研究中，我们证明 K33S rCan 在豚鼠中是安全的且减毒的，并且能够引发有效的病毒中和抗体。免疫动物得到充分保护，免受有毒 JUNV 的致命攻击。此外，我们在新生小鼠中采用了更宽松的感染模型来研究基因逆转。对回收病毒的RNA序列分析发现，在接种亲本rCan病毒的幼犬中存在回复病毒，而在接受K33S rCan病毒的小鼠中则没有发现回复病毒（P< 0.0001）。总而言之，我们的研究结果支持进一步开发 K33S rCan 作为安全的第二代 JUNV 疫苗。 重要性 我们最成功的疫苗包含弱化病毒株，可在免疫人群中引发有限的良性感染。胡宁病毒 (JUNV) 减毒活 Candid#1 毒株是为了保护阿根廷的现场工作人员免受啮齿动物传播的出血热而开发的，但在美国未获得许可，部分原因是基因毒力回复的可能性。病毒GPC包膜糖蛋白中的单个氨基酸变化导致减毒，单个核苷酸变化可能使致病病毒再生。在这里，我们利用 GPC 亚基之间独特的遗传相互作用来设计一种突变型 Candid#1 病毒，该病毒建立了逆转的进化障碍。突变病毒 (K33S rCan) 已完全减毒，可保护免疫豚鼠免受致命的 JUNV 感染。我们没有发现接种 K33S rCan 的小鼠出现逆转的情况。这项工作支持 K33S rCan 作为第二代 JUNV 疫苗的进一步开发。
Live-attenuated virus vaccines are highly effective in preventing viral disease but carry intrinsic risks of residual virulence and reversion to pathogenicity. The classically derived Candid#1 virus protects seasonal field workers in Argentina against zoonotic infection by Junín virus (JUNV) but is not approved in the United States, in part due to the potential for reversion at the attenuating locus, a phenylalanine-to-isoleucine substitution at position 427 in the GP2 subunit of the GPC envelope glycoprotein. Previously, we demonstrated facile reversion of recombinant Candid#1 (rCan) in cell culture and identified an epistatic interaction between the attenuating I427 and a secondary K33S mutation in the stable signal peptide (SSP) subunit of GPC that imposes an evolutionary barrier to reversion. The magnitude of this genetic barrier is manifest in our repeated failures to rescue the hypothetical revertant virus. In this study, we show that K33S rCan is safe and attenuated in guinea pigs and capable of eliciting potent virus-neutralizing antibodies. Immunized animals are fully protected against lethal challenge with virulent JUNV. In addition, we employed a more permissive model of infection in neonatal mice to investigate genetic reversion. RNA sequence analysis of the recovered virus identified revertant viruses in pups inoculated with the parental rCan virus and none in mice receiving K33S rCan (P< 0.0001). Taken together, our findings support the further development of K33S rCan as a safe second-generation JUNV vaccine.IMPORTANCEOur most successful vaccines comprise weakened strains of virus that initiate a limited and benign infection in immunized persons. The live-attenuated Candid#1 strain of Junín virus (JUNV) was developed to protect field workers in Argentina from rodent-borne hemorrhagic fever but is not licensed in the United States, in part due to the likelihood of genetic reversion to virulence. A single-amino-acid change in the GPC envelope glycoprotein of the virus is responsible for attenuation, and a single nucleotide change may regenerate the pathogenic virus. Here, we take advantage of a unique genetic interaction between GPC subunits to design a mutant Candid#1 virus that establishes an evolutionary barrier to reversion. The mutant virus (K33S rCan) is fully attenuated and protects immunized guinea pigs against lethal JUNV infection. We find no instances of reversion in mice inoculated with K33S rCan. This work supports the further development of K33S rCan as a second-generation JUNV vaccine.