Key Laboratory of Genetic Evolution and Animal Models, Key Laboratory of Animal Models and Human Disease Mechanisms of Yunnan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650204, China; Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650204, China; Kunming National High-Level Biosafety Research Center for Non-Human Primates, Center for Biosafety Mega-Science, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650107, China.
Key Laboratory of Genetic Evolution and Animal Models, Key Laboratory of Animal Models and Human Disease Mechanisms of Yunnan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650204, China; Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650204, China; Kunming National High-Level Biosafety Research Center for Non-Human Primates, Center for Biosafety Mega-Science, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650107, China.
EBioMedicine. 2024 Sep;107:105281. doi: 10.1016/j.ebiom.2024.105281. Epub 2024 Aug 13.
Coronavirus disease 2019 (COVID-19) is an immune-related disorder caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The complete pathogenesis of the virus remains to be determined. Unraveling the molecular mechanisms governing SARS-CoV-2 interactions with host cells is crucial for the formulation of effective prophylactic measures and the advancement of COVID-19 therapeutics.
We analyzed human lung single-cell RNA sequencing dataset to discern the association of butyrophilin subfamily 3 member A2 (BTN3A2) expression with COVID-19. The BTN3A2 gene edited cell lines and transgenic mice were infected by live SARS-CoV-2 in a biosafety level 3 (BSL-3) laboratory. Immunoprecipitation, flow cytometry, biolayer interferometry and competition ELISA assays were performed in BTN3A2 gene edited cells. We performed quantitative real-time PCR, histological and/or immunohistochemical analyses for tissue samples from mice with or without SARS-CoV-2 infection.
The BTN3A2 mRNA level was correlated with COVID-19 severity. BTN3A2 expression was predominantly identified in epithelial cells, elevated in pathological epithelial cells from COVID-19 patients and co-occurred with ACE2 expression in the same lung cell subtypes. BTN3A2 targeted the early stage of the viral life cycle by inhibiting SARS-CoV-2 attachment through interactions with the receptor-binding domain (RBD) of the Spike protein and ACE2. BTN3A2 inhibited ACE2-mediated SARS-CoV-2 infection by reducing ACE2 in vitro and in vivo.
These results reveal a key role of BTN3A2 in the fight against COVID-19. Identifying potential monoclonal antibodies which mimic BTN3A2 may facilitate disruption of SARS-CoV-2 infection, providing a therapeutic avenue for COVID-19.
This study was supported by the National Natural Science Foundation of China (32070569, U1902215, and 32371017), the CAS "Light of West China" Program, and Yunnan Province (202305AH340006).
新型冠状病毒病 2019（COVID-19）是由严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）引起的免疫相关疾病。病毒的完整发病机制仍有待确定。阐明病毒与宿主细胞相互作用的分子机制对于制定有效的预防措施和推进 COVID-19 治疗至关重要。
我们分析了人类肺单细胞 RNA 测序数据集，以发现 BTN3A2 表达与 COVID-19 的关联。在生物安全 3 级（BSL-3）实验室中，使用活 SARS-CoV-2 感染 BTN3A2 基因编辑的细胞系和转基因小鼠。在 BTN3A2 基因编辑细胞中进行免疫沉淀、流式细胞术、生物层干涉和竞争 ELISA 测定。对感染或未感染 SARS-CoV-2 的小鼠的组织样本进行定量实时 PCR、组织学和/或免疫组织化学分析。
BTN3A2 mRNA 水平与 COVID-19 严重程度相关。BTN3A2 表达主要在上皮细胞中鉴定，在 COVID-19 患者的病理性上皮细胞中上调，并且与同一肺细胞亚型中的 ACE2 表达共发生。BTN3A2 通过与 Spike 蛋白的受体结合域（RBD）相互作用，抑制 SARS-CoV-2 附着，从而靶向病毒生命周期的早期阶段。BTN3A2 通过减少体外和体内的 ACE2 来抑制 ACE2 介导的 SARS-CoV-2 感染。
这些结果揭示了 BTN3A2 在对抗 COVID-19 中的关键作用。鉴定模仿 BTN3A2 的潜在单克隆抗体可能有助于破坏 SARS-CoV-2 感染，为 COVID-19 提供治疗途径。
本研究得到国家自然科学基金（32070569、U1902215 和 32371017）、中国科学院“西部之光”项目和云南省（202305AH340006）的支持。
