SARS-CoV-2 Beta变异株和甲型流感病毒H3N2双价重组腺病毒载体疫苗可在小鼠诱导免疫保护

A Novel Bivalent Recombinant Adenovirus Vector Vaccine Induces Immune Protection in Mice Against SARS-CoV-2 Beta Variant and Influenza A Virus H3N2

评价一种SARS-CoV-2 Beta变异株和甲型流感病毒H3N2新型重组双价疫苗在小鼠模型中的免疫保护效果。本研究构建了表达SARS-CoV-2南非变异株(B.1.351)棘突蛋白1(S1)和H3N2柬埔寨分离株(A/Cambodia/e0826360/2020)血凝素(HA)的重组双价非复制Ad5载体疫苗,命名为HAdV5-S1-2A-HA,经单针肌肉注射免疫BALB/c雌鼠后,采用ELISA、血凝抑制实验、假病毒中和实验与Elispot实验进行体液与细胞免疫学检测,免后3~6周采用H3N2-X31病毒、H1N1-PR8与SARS-CoV-2(B.1.351)进行攻毒保护实验。HAdV5-S1-2A-HA免疫两周后,低剂量组(1×10^(8)vp/只)免疫小鼠后可检出HA特异体液免疫与S1特异的细胞免疫应答;而高剂量组(5×10^(9)vp/只)诱导小鼠产生了较强的双抗原(S1,HA)特异的体液和细胞免疫应答,并能完全保护小鼠对H3N2-X31攻击,降低SARS-CoV-2(B.1.351)感染后小鼠肺部病毒载量,延迟H1N1-PR8病毒感染后小鼠死亡发生。本研究制备的重组双价疫苗HAdV5-S1-2A-HA在小鼠体内诱导抗原特异的体液与细胞免疫应答。同时,它还可以在小鼠中诱导对SARS-CoV-2和H3N2感染的免疫保护,具有较好的研发与应用前景。

To evaluate the immunological protective effect of a novel recombinant bivalent vaccine against SARS-CoV-2 Beta variant and influenza A virus H3N2 in a mouse model.We construct an adenovirus 5(Ad5)-based bivalent vaccines designed to Spike 1(S1)from SARS-CoV-2(B.1.351)and hemagglutinin(HA)from the H3N2 Cambodia strain(A/Cambodia/e0826360/2020),which we named“HAdV5-S1-2A-HA”.ELISA,hemagglutination inhibition test,pseudovirus neutralization test and Elispot assay were used for detection of humoral and cellular immunological responses in BALB/c female mice after a single immunization by intramuscular injection.Then challenge protections against H3N2-X31,H1N1-PR8 and SARS-CoV-2(B.1.351)were performed in mice 3-6weeks post immunization.Two weeks after HAdV5-S1-2A-HA immunization,HA-specific humoral immunity and S1-specific cellular immune responses could be detected in the low-dose group(1×10^(8)vp/mouse),while the high-dose group(5×10^(9)vp/mouse)induced robust dual-antigen(S1,HA)-specific humoral and cellular immune responses,and could protect mice completely against H3N2-X31 challenge and extenuate SARS-CoV-2(B.1.351)infection based on reduction of the viral load in mouse lungs,delayed death occurs in immunized mice with high dose of HAdV5-S1-2A-HA after H1N1-PR8virus infection.The recombinant bivalent vaccine HAdV5-S1-2A-HA developed in this study induced antigenspecific humoral and cellular immune responses in mice.Furthermore it also induced immune protection against SARS-CoV-2 and H3N2 infection in mice,which has good application prospects for further research and development.