Xu Jiaxin, Liu Yuanni, Zhang Fan, Wang Xin, Huang Weijin, Wu Yulong, Li Boqing, Zhuang Jiapeng, Bing Yixing, Wang Youchun, Qiao Yuanyuan
Department of Pathogenic Biology, Binzhou Medical University, Yantai, China.
Department of Infectious Diseases and Clinical Laboratory, Yantai Qishan Hospital, Yantai, China.
Front Microbiol. 2022 Oct 20;13:1020545. doi: 10.3389/fmicb.2022.1020545. eCollection 2022.
Severe fever with thrombocytopenia syndrome bunyavirus (SFTSV) is a tick-borne virus that causes severe communicable fever with thrombocytopenia syndrome (SFTS) with an average case fatality rate of 10%. In the study, we aimed to identify the cross-neutralizing antibody (nAb) against different genotype strains from sera of SFTSV infected patients.
Firstly the genotype of SFTSV was identified by constructing a phylogenetic tree based on the M segments epidemic in the Jiaodong area of Shandong province, then different sera of subjects cross reactive with recombinant Gn (rGn-Fc) or recombinant Gc (rGc-Fc) of 0921 strain were examined. The levels of polyclonal nAbs from sera of 25 convalescents were measured by a pseudovirus-based neutralizing experiment.
We found local endemic strains were mainly C2 and C3 isolates of SFTSV. 14 of 15 sera from donors reacted with 0921 rGn-Fc, and 9 of 15 sera from donors reacted with 0921 rGc-Fc. Cross nAbs were produced by 10 of 25 sera from donors during the period of 2019-2021. Among these, five nAbs (A2, A4, A5, L9, and L10) neutralized the pseudoviruses of HB29, Gangwon, HN13, HN20, SPL030A, and SD4 strains.
Our data suggested that epidemic strains showed relatively stable heredity. Some blood sources from patients produced cross nAbs that could neutralize all of the strains examined. These findings highlight the important role played by humoral immunity in combatting SFTSV.
发热伴血小板减少综合征布尼亚病毒（SFTSV）是一种蜱传病毒，可引起发热伴血小板减少综合征（SFTS），平均病死率为10%。在本研究中，我们旨在从SFTSV感染患者血清中鉴定针对不同基因型毒株的交叉中和抗体（nAb）。
首先基于山东省胶东地区流行的M片段构建系统发育树来鉴定SFTSV的基因型，然后检测与0921株重组Gn（rGn-Fc）或重组Gc（rGc-Fc）发生交叉反应的不同受试者血清。通过基于假病毒的中和实验检测25名康复者血清中多克隆nAb的水平。
我们发现当地流行毒株主要是SFTSV的C2和C3分离株。15名供体的血清中有14份与0921 rGn-Fc反应，15名供体的血清中有9份与0921 rGc-Fc反应。2019年至2021年期间，25名供体的血清中有10份产生了交叉nAb。其中，五种nAb（A2、A4、A5、L9和L10）中和了HB29、江原道、HN13、HN20、SPL030A和SD4株的假病毒。
我们的数据表明流行毒株显示出相对稳定的遗传性。一些患者的血液样本产生了能够中和所有检测毒株的交叉nAb。这些发现突出了体液免疫在对抗SFTSV中的重要作用。
