Novel rabies virus vaccines that exploit innate immune signals

描述（由申请人提供）：世界上超过三分之二的人口生活在狂犬病流行的地区，导致全球每年有超过1500万人接受多剂量暴露后预防（PEP），超过7.5万人死亡。狂犬病病毒（RV）研究的一个主要目标是开发单剂量暴露后预防（PEP），以简化疫苗接种方案，降低与RV预防相关的成本，并挽救生命。基于复制缺陷的活病毒载体正在成为实现这一目标的有希望的疫苗。多种信号导致最佳的B细胞激活和功能。在这些信号中，BAFF和APRIL通过影响B细胞和T细胞功能架起了先天免疫和适应性免疫之间的桥梁。我们假设，表达BAFF或APRIL的复制缺陷型RV活疫苗将比亲本的RV活疫苗更有效地诱导快速和强大的RV特异性免疫和对致病性RV攻击的保护。本应用的主要目的是研究B细胞活化和RV特异性免疫，以及对表达BAFF或APRIL的复制缺陷型RV活疫苗引发的致病性RV攻击的保护，并证实免疫病理的缺失。第一个目标是构建、恢复和表征表达BAFF或APRIL的活基质(M)基因缺失的rv疫苗载体（rRV- M）。第二个目标是完成一项综合评估，在rv特异性B细胞激活、免疫、保护和安全性的背景下，从基于rv的活疫苗载体表达BAFF或APRIL的功能后果。定性和定量测量B细胞和抗体属性（B细胞活化、病毒中和活性、抗体亲和力和亚类谱），以及CD4 T细胞（细胞内细胞因子染色显示Th1/Th2偏倚），这是主要的抗病毒反应

DESCRIPTION (provided by applicant): Over two-thirds of the world's population live in regions where rabies is endemic, resulting in over 15 million people receiving multi-dose post-exposure prophylaxis (PEP) and over 75,000 deaths per year globally. A major goal in rabies virus (RV) research is to develop a single-dose post-exposure prophylaxis (PEP) that would simplify vaccination protocols, reduce costs associated with RV prevention, and save lives. Live replication-deficient RV-based vectors are emerging as promising vaccines to achieve this goal. Multiple signals lead to optimal B cell activation and functions. Among these signals, BAFF and APRIL bridge the gap between innate and adaptive immunity by influencing B and T cell functions. We hypothesize that live replication-deficient RV-based vaccines expressing BAFF or APRIL will induce rapid and robust RV-specific immunity and protection against pathogenic RV challenge more effectively than a parental live RV-based vaccine. The major goal of this application is to investigate B cell activation and RV-specific immunity and protection against pathogenic RV challenge elicited by live replication-deficient RV-based vaccines expressing BAFF or APRIL and to confirm the absence of immune pathology. The goal for the first Aim is to construct, recover and characterize live matrix (M) gene-deleted RV-based vaccine vectors (rRV- M) expressing BAFF or APRIL. The goal of the second Aim is to complete a comprehensive evaluation of the functional consequences of expressing BAFF or APRIL from live RV-based vaccine vectors in the context of RV-specific B cell activation, immunity, protection and safety. Qualitative and quantitative measures of B cell and antibody attributes (B cell activation, virus neutralization activity, antibody avidity and subclass profile), and CD4 T cells (Th1/Th2 bias by intracellular cytokine staining), which are the primary anti-viral responses critical for RV PEP, will be analyzed using a mouse model of RV immunogenicity and protection. The absence of autoimmunity, B cell lymphocytic disorders and extreme inflammatory responses will be monitored to help confirm the new vaccines remain safe. This exploratory grant will potentially identify a single-dose vaccine strategy that exploits the speed by which innate immunity promotes adaptive B cell responses, resulting in antibodies capable of rapidly neutralizing and preventing RV infections. Future goals include additional testing to identify the most effective vaccination strategy, safety, and toxicity in pre-clinical settings with the ultimat goal of reducing the cost of rabies prevention in humans and saving lives.