A replication-defective tick-borne encephalitis virus generated by NS1 <i>trans</i>-complementation confers robust protective efficacy

Ji Zhang; Qiu-Yan Zhang; Zhe-Rui Zhang; Ya-Nan Zhang; Hong-Qing Zhang; Cheng-Lin Deng; Bo Zhang

doi:10.1016/j.virs.2026.07.010

August 2026

. doi: 10.1016/j.virs.2026.07.010

Citation: Ji Zhang, Qiu-Yan Zhang, Zhe-Rui Zhang, Ya-Nan Zhang, Hong-Qing Zhang, Cheng-Lin Deng, Bo Zhang. A replication-defective tick-borne encephalitis virus generated by NS1 trans-complementation confers robust protective efficacy .VIROLOGICA SINICA, 2026, 41(4) : 937-946. http://dx.doi.org/10.1016/j.virs.2026.07.010

通过NS1反式互补系统产生具有强保护效力的复制缺陷型蜱传脑炎病毒

中国科学院武汉病毒研究所

通讯作者： 邓成林, dengcl@wh.iov.cn; 张波, zhangbo@wh.iov.cn
收稿日期： 2026-01-04
录用日期： 2026-07-28

摘要

蜱传脑炎病毒（Tick-borne encephalitis virus，TBEV）对公共卫生构成严重威胁，在流行区可引起高发病率和高死亡率的神经系统疾病。因此，开发安全有效的TBEV疫苗策略一直是研究的重点。在此，利用我们已建立的成熟的NS1反式互补平台，使用稳定表达鄂木斯克出血热病毒（Omsk hemorrhagic fever virus，OHFV）NS1蛋白的BHK-21细胞系（命名为BHKNS1），成功构建了一株高滴度的复制缺陷型TBEV（TBEV-△NS1）。通过在BHKNS1细胞中连续传代，证实了TBEV-△NS1中NS1缺失得以稳定维持，在正常BHK-21细胞中未检测到复制型病毒。此外，TBEV-△NS1的安全性得到了全面验证，对ICR小鼠给予高剂量TBEV-△NS1未诱导任何临床症状。值得注意的是，TBEV-△NS1能够完全保护ICR小鼠免受致死性野生型（WT）TBEV的攻击，而未免疫的对照小鼠则表现出100%的死亡率、体重下降和病毒血症。这种保护效果与强大的体液和细胞免疫应答密切相关，单次免疫后即可诱导高滴度的TBEV特异性IgG、中和抗体以及分泌IFN-γ的CD8⁺阳性T细胞。综上，NS1反式互补策略为TBEV疫苗研发提供了可行路径。
- 蜱传脑炎病毒（TBEV）
- , NS1
- , 反式互补策略
- , 疫苗

A replication-defective tick-borne encephalitis virus generated by NS1 trans-complementation confers robust protective efficacy

State Key Laboratory of Virology and Biosafety, Wuhan Institute of Virology, Wuhan 430071, China

Corresponding author: Cheng-Lin Deng, dengcl@wh.iov.cn Bo Zhang, zhangbo@wh.iov.cn
Received Date: 04 January 2026
Accepted Date: 28 July 2026

Abstract

Tick-borne encephalitis virus (TBEV) poses a severe threat to public health, causing neurological disorders with high morbidity and mortality in endemic regions. Therefore, developing safe and effective strategies for TBEV vaccines has long been a focus of attention. Herein, leveraging our well-established NS1 trans-complementation platform, we successfully constructed a high-titer replication-defective TBEV (TBEV-△NS1) using the BHK-21 cell line stably expressing Omsk hemorrhagic fever virus (OHFV) NS1 (designated BHK_NS1). Retention of the NS1 deletion in TBEV-△NS1 was confirmed by continuous passaging in BHK_NS1 cells, as no replicative virus was detected in naive BHK-21 cells. The safety profile of TBEV-△NS1 was further validated, as administration of a high dose of TBEV-△NS1 to ICR mice did not induce any clinical symptoms. Notably, TBEV-△NS1 conferred complete protection against lethal wild-type (WT) TBEV challenge in ICR mice, whereas non-immunized control mice exhibited 100% mortality, significant weight loss, and viremia. This protective efficacy is tightly correlated with robust humoral and cellular immune responses, as demonstrated by the induction of high titers of TBEV-specific IgG, neutralizing antibodies, and IFN-γ-secreting CD8⁺ T cells following a single immunization. Collectively, our findings provide a proof-of-concept for the NS1 trans-complementation platform in TBEV vaccine development.
- Tick-borne encephalitis virus (TBEV)
- , NS1
- , Trans-complementation strategy
- , Vaccine

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