Due to the insufficient long-term protection and significant efficacy reduction to new variants of current COVID-19 vaccines,the epidemic prevention and control are still challenging.Here,we employ a capsid and antige...Due to the insufficient long-term protection and significant efficacy reduction to new variants of current COVID-19 vaccines,the epidemic prevention and control are still challenging.Here,we employ a capsid and antigen structure engineering(CASE)strategy to manufacture an adenoassociated viral serotype 6-based vaccine(S663V-RBD),which expresses trimeric receptor binding domain(RBD)of spike protein fused with a biological adjuvant RS09.Impressively,the engineered S663V-RBD could rapidly induce a satisfactory RBD-specific IgG titer within 2 weeks and maintain the titer for more than 4 months.Compared to the licensed BBIBP-CorV(Sinopharm,China),a single-dose S663V-RBD induced more endurable and robust immune responses in mice and elicited superior neutralizing antibodies against three typical SARS-CoV-2 pseudoviruses including wild type,C.37(Lambda)and B.1.617.2(Delta).More interestingly,the intramuscular injection of S663V-RBD could overcome pre-existing immunity against the capsid.Given its effectiveness,the CASE-based S663VRBD may provide a new solution for the current and next pandemic.展开更多
常用的基因治疗表达载体有病毒表达载体和质粒表达载体,这两类传统基因治疗载体含有大量病毒或细菌DNA序列,会引发人体较严重的免疫反应、细胞炎症、细胞毒性副作用、以及基因表达沉默化,是基因治疗应用于人类疾病治疗的一大障碍。项目...常用的基因治疗表达载体有病毒表达载体和质粒表达载体,这两类传统基因治疗载体含有大量病毒或细菌DNA序列,会引发人体较严重的免疫反应、细胞炎症、细胞毒性副作用、以及基因表达沉默化,是基因治疗应用于人类疾病治疗的一大障碍。项目构建了一种新型的、基于腺相关病毒(AAV)倒置末端重复序列(ITR)的基因表达单链微载体(AAV-ITR mini vector),并用GFP基因作为报告基因。通过热变性的方法制备单链DNA,然后将带有GFP的质粒、双链DNA载体、AAV-ITR基因表达微载体转入真核表达细胞,采用荧光显微镜观察和流式细胞仪检测等较为简单的方法来检测其表达效率。实验结果显示,AAV-ITR基因表达微载体在293T细胞中具有较高的转染、表达效率,并且具有类似AAV病毒载体的特性。该研究结果将有助于进一步研发类似于AAV病毒载体的安全、无免疫原性的人造基因治疗载体。展开更多
ADENO-ASSOCIATED virus (AAV) was a human parvovirus considered as a gene delivery vehiclefor human gene therapy. Recombinant AAV vector (rAAV) could mediate the foreign DNAintegration into chromosome and establish a s...ADENO-ASSOCIATED virus (AAV) was a human parvovirus considered as a gene delivery vehiclefor human gene therapy. Recombinant AAV vector (rAAV) could mediate the foreign DNAintegration into chromosome and establish a stable expression in the infected cells. As a viraltransduction vector, rAAV was superior to the traditional retrovirus vector for its high safety.no pathogenicity, and capacity of infecting postmitosis cells. The current strategy for produc-展开更多
AAV-ITR单链DNA微载体是一种基于腺相关病毒(AAV)倒置末端重复序列(ITR)的基因表达载体(AAV-ITR ss DNA mini vector)。前期研究已证明AAV-ITR单链DNA微载体在HEK 293T细胞中具有较高的转染、表达效率。本文中将相同拷贝数的AAV-ITR单链...AAV-ITR单链DNA微载体是一种基于腺相关病毒(AAV)倒置末端重复序列(ITR)的基因表达载体(AAV-ITR ss DNA mini vector)。前期研究已证明AAV-ITR单链DNA微载体在HEK 293T细胞中具有较高的转染、表达效率。本文中将相同拷贝数的AAV-ITR单链DNA微载体、3?-ITR末端错配的AAV-ITR单链DNA微载体(AAV-ITRmm ss DNA mutant vector)、AAV-ITR双链DNA和质粒分别用Turbo Fect转入小鼠骨骼肌中,比较检测AAV-ITR单链DNA微载体与其他基因表达载体在小鼠体内1周、1个月及3个月的表达效率。组织切片经荧光显微镜观察及荧光灰度值分析表明,相同分子摩尔数的AAV-ITR单链DNA微载体比AAV-ITR双链DNA和质粒在不同时期表达效率都要高且更稳定。提取注射3个月后的肌肉组织的DNA,用荧光定量PCR分析比较各载体的存留分子数。RT-PCR的结果显示AAV-ITR单链DNA微载体在注射3个月后的存留分子数较其他载体高。综合结果显示AAV-ITR单链DNA微载体在动物体内具有表达效率高和长久稳定的优势,有可能开发为基因治疗的一种高效、稳定的新型载体。展开更多
文摘空间矢量调制(Space Vector Modulation,SVM)方法在降低逆变器开关频率,提高直流母线电压利用率方面具有独特的优势。为深入探索SVM的本质特征,简化SVM的实现方法并为新型调制方法的产生提供启发,阐述了通过分析三相全桥电路开关脉冲本质特征而建立的一种活动面积矢量(Active Area Vector,AAV)的分析方法;建立了AAV与开关脉冲的对应关系,并推导了不同AAV之间的等价变换性质。将AAV分析方法应用于SVM中可有效改善传统SVM运算量大的问题。仿真和实验结果验证了AAV活动面积矢量分析方法的正确性及其应用于SVM中的可行性。
基金the National Natural Science Foundation of China,China(Grant Nos.81925036 and 81872814)the Key Research and Development Program of Science and Technology Department of Sichuan Province,China(Grant No.2020YFS0570)+1 种基金111 project,China(Grant No.B18035)the Fundamental Research Funds for the Central Universities,China。
文摘Due to the insufficient long-term protection and significant efficacy reduction to new variants of current COVID-19 vaccines,the epidemic prevention and control are still challenging.Here,we employ a capsid and antigen structure engineering(CASE)strategy to manufacture an adenoassociated viral serotype 6-based vaccine(S663V-RBD),which expresses trimeric receptor binding domain(RBD)of spike protein fused with a biological adjuvant RS09.Impressively,the engineered S663V-RBD could rapidly induce a satisfactory RBD-specific IgG titer within 2 weeks and maintain the titer for more than 4 months.Compared to the licensed BBIBP-CorV(Sinopharm,China),a single-dose S663V-RBD induced more endurable and robust immune responses in mice and elicited superior neutralizing antibodies against three typical SARS-CoV-2 pseudoviruses including wild type,C.37(Lambda)and B.1.617.2(Delta).More interestingly,the intramuscular injection of S663V-RBD could overcome pre-existing immunity against the capsid.Given its effectiveness,the CASE-based S663VRBD may provide a new solution for the current and next pandemic.
文摘常用的基因治疗表达载体有病毒表达载体和质粒表达载体,这两类传统基因治疗载体含有大量病毒或细菌DNA序列,会引发人体较严重的免疫反应、细胞炎症、细胞毒性副作用、以及基因表达沉默化,是基因治疗应用于人类疾病治疗的一大障碍。项目构建了一种新型的、基于腺相关病毒(AAV)倒置末端重复序列(ITR)的基因表达单链微载体(AAV-ITR mini vector),并用GFP基因作为报告基因。通过热变性的方法制备单链DNA,然后将带有GFP的质粒、双链DNA载体、AAV-ITR基因表达微载体转入真核表达细胞,采用荧光显微镜观察和流式细胞仪检测等较为简单的方法来检测其表达效率。实验结果显示,AAV-ITR基因表达微载体在293T细胞中具有较高的转染、表达效率,并且具有类似AAV病毒载体的特性。该研究结果将有助于进一步研发类似于AAV病毒载体的安全、无免疫原性的人造基因治疗载体。
文摘ADENO-ASSOCIATED virus (AAV) was a human parvovirus considered as a gene delivery vehiclefor human gene therapy. Recombinant AAV vector (rAAV) could mediate the foreign DNAintegration into chromosome and establish a stable expression in the infected cells. As a viraltransduction vector, rAAV was superior to the traditional retrovirus vector for its high safety.no pathogenicity, and capacity of infecting postmitosis cells. The current strategy for produc-
文摘AAV-ITR单链DNA微载体是一种基于腺相关病毒(AAV)倒置末端重复序列(ITR)的基因表达载体(AAV-ITR ss DNA mini vector)。前期研究已证明AAV-ITR单链DNA微载体在HEK 293T细胞中具有较高的转染、表达效率。本文中将相同拷贝数的AAV-ITR单链DNA微载体、3?-ITR末端错配的AAV-ITR单链DNA微载体(AAV-ITRmm ss DNA mutant vector)、AAV-ITR双链DNA和质粒分别用Turbo Fect转入小鼠骨骼肌中,比较检测AAV-ITR单链DNA微载体与其他基因表达载体在小鼠体内1周、1个月及3个月的表达效率。组织切片经荧光显微镜观察及荧光灰度值分析表明,相同分子摩尔数的AAV-ITR单链DNA微载体比AAV-ITR双链DNA和质粒在不同时期表达效率都要高且更稳定。提取注射3个月后的肌肉组织的DNA,用荧光定量PCR分析比较各载体的存留分子数。RT-PCR的结果显示AAV-ITR单链DNA微载体在注射3个月后的存留分子数较其他载体高。综合结果显示AAV-ITR单链DNA微载体在动物体内具有表达效率高和长久稳定的优势,有可能开发为基因治疗的一种高效、稳定的新型载体。
