Next generation vaccines for bovine respiratory disease (BRD) complex utilizing virus vaccine vectors to target both bacterial and viral pathogens.

牛呼吸道疾病（BRD）是一种受环境压力、宿主免疫反应和多种病原体共同影响的复杂疾病。这种病在被封闭饲养的小牛中最为普遍，由于它与动物运动有关，因此被称为运输热。BRD的经济后果在世界范围内具有重大意义，例如，一项饲料场研究表明，六分之一以上的牛受到BRD的影响，死亡率超过2%，受BRD影响的牛的净收益减少50%。BRD是由易感牛的呼吸道病毒感染引起的，其中最流行的是牛疱疹病毒1 （BoHV-1）、牛呼吸道合胞病毒（BRSV）和副流感病毒3 （PI3）。继发感染细菌病原体，特别是溶血性曼海姆病和多杀性巴氏杆菌，随后导致临床疾病。莫尔顿研究所（MRI）和Ceva Sante Animale （Ceva）正在积极开发针对引起BRD的病原体的新疫苗。在Moredun，我们开发了疫苗载体，使用我们的四个疫苗载体平台从病毒病原体中递送抗原有效载荷。同时，Ceva已经确定了来自相同病毒病原体和2种细菌病原体的抗原，作为多价重组蛋白疫苗的潜在疫苗有效载荷。这些目前正在Moredun进行测试，特别是由合同研究组织（CRO）， Moredun科学有限公司进行测试。在本提案中，我们（从Ceva抗原中）选择了一种来自细菌的蛋白质和一种来自病毒的蛋白质来测试所有载体格式。这两种病毒都将被克隆到正在研究的每一种载体中，特别是复制缺陷型人类腺病毒5 （Ad5）、马氏腺病毒（MV）、阿尔celaphine herpesvirus 1 （AlHV-1）和Orf病毒。所有表达目标抗原（A来自病毒，B来自细菌，来自Ceva抗原）的疫苗载体将在进行动物试验之前进行体外测试，作为预筛选。如果像预期的那样，它们都能在体外表达蛋白质载荷，那么它们将在牛身上进行测试。我们将检测血清抗体反应、粘膜抗体反应和CD4 T辅助细胞反应的比较水平。结果将提供数据，以确定这些载体中的一个或多个在递送选定抗原方面是否优于其他载体。此外，我们将证明这些载体是否比佐剂中的重组蛋白和目前可用的商业疫苗诱导更强、更持久的免疫反应。如果任何一种病媒疫苗表现优异，这将推动开发更有效的BRD疫苗。这些载体系统允许在单一有效载荷中递送多种蛋白质，从而提供多价疫苗。如果发现新的、抗原性不同的细菌或病毒病原体菌株，它们还允许快速改变有效载荷。此外，这些载体不需要佐剂来递送，消除了费用并减少了强佐剂经常出现的注射反应。

Bovine respiratory disease (BRD) is a complex condition influenced by a combination of environmental stressors, host immune responses, and multiple pathogens. It is most prevalent in young cattle that are housed in close quarters and was called shipping fever due to its association with animal movements. The economic consequences of BRD are significant worldwide, for example, one feed lot study showing more than one in six cattle being affected by BRD and over 2% mortality, with a reduction in net return of 50% in affected cattle. BRD is initiated in susceptible cattle by respiratory virus infections, with bovine herpesvirus 1 (BoHV-1), bovine respiratory syncytial virus (BRSV) and parainfluenza virus 3 (PI3) being among the most prevalent. Secondary infections with bacterial pathogens, in particular Mannheimia haemolytica and Pasteurella multocida, follow leading to clinical disease.Moredun Research Institute (MRI) and Ceva Sante Animale (Ceva) have active programs developing new vaccines for the pathogens that cause BRD. At Moredun, we have developed vaccine vectors to deliver antigen payloads from the virus pathogens using four of our vaccine vector platforms. Concurrently, Ceva has identified antigens from the same viral pathogens as well as 2 bacterial pathogens as potential vaccine payloads for a multivalent recombinant protein vaccine. These are presently being tested at Moredun, specifically by the contract research organization (CRO), Moredun Scientific, Ltd. In this proposal, we have selected (from the Ceva antigens) one protein from bacteria and one protein from a virus to test in all of the vector formats. These will both be cloned into each of the vectors under study, specifically, replication defective human adenovirus 5 (Ad5), Maedi visna virus (MV), Alcelaphine herpesvirus 1 (AlHV-1), and Orf virus. All vaccine vectors made expressing the targeted antigens (A from a virus and B from a bacterium, from the Ceva antigens) will be tested in vitro as a pre-screen before conducting animal trials. If, as expected, all express the protein payload in vitro, they will be tested in cattle. We will assay for serum antibody responses, mucosal antibody responses, and the comparative levels of CD4 T helper cell responses. Results will provide data to determine if one or more of these vectors out-perform the others in the delivery of the selected antigens. Further, we will demonstrate whether these vectors induce stronger and more protracted immune responses than the recombinant proteins in adjuvant as well as presently available commercial vaccines. If any of the vectored vaccines are superior performers, this will advance the development of more effective BRD vaccines. These vector systems allow for delivery of multiple proteins in a single payload, providing multivalent vaccines. They also allow rapid change of the payload if new, antigenically divergent strains of either bacteria or virus pathogens are identified. Additionally, these vectors do not require adjuvants for delivery, removing that expense and reducing injection reactions often seen with strong adjuvants.