Defining clinically relevant viral epitopes with cow antibodies

疫苗是预防、控制或根除传染病的主要手段。 疾病。虽然许多疫苗已经成功开发并导致了 巨大的医疗和兽医效益，有一些病毒已经逃脱了 有效的疫苗研发。一般来说，具有多个毒株或高病毒株的病毒 突变率可以躲避中和抗体，因为它们的表面决定因素是 并导致针对一种毒株产生的中和抗体不能 结合和中和替代菌株。然而，某些罕见的表位是需要的 病毒感染，并在不同株系之间保守。有趣的是，中和抗体 针对这些稀有的表位，往往有很长的CDR H3区。在艾滋病毒的情况下，龙 CDR H3s可以穿透病毒的多糖保护膜，进入病毒表面的保守表位。 Gp120刺突蛋白。虽然人类抗体中的CDR H3长区域在 在曲目中，牛通常产生长(20-40个氨基酸)和超长(40-70个氨基酸) 氨基酸)CDR H3区具有独特的“柄”和“节”结构特征， 远离抗体表面的突起。因此，牛可能是一个很好的模型 生物体识别和定义这些新的和保守的中和表位 挑战病毒。事实上，在初步实验中，我们已经发现牛能制造 针对HIV gp120抗原的强大且广泛中和的抗体反应。在这里我们 建议使用独特的奶牛抗体库来定义新的保守中和 对人类和动物健康非常重要的两种病毒的表位：艾滋病毒和 BVDV。针对这两种病毒的有效疫苗一直是对 发展。我们将对动物进行免疫以对抗这些病毒，产生单克隆 中和病毒和相关毒株的抗体，并从分子上映射 使用诱变和结构生物学技术的抗原-抗体相互作用。 新的保守表位的定义可能导致基因工程表位特异性疫苗的产生。 因此，这项提议的结果可以使下一代 这两种病毒的疫苗，但在疫苗开发中也可能有广泛的用途 在未来对抗其他具有挑战性的病毒。

Vaccines are the primary means by which to prevent, control, or eradicate infectious diseases. While many vaccines have been successfully developed and have resulted in enormous medical and veterinary benefit, there are certain viruses that have eluded effective vaccine development. Generally, viruses with multiple strains or that have high mutation rates can evade neutralizing antibodies, as their surface determinants are variable and result in the inability of neutralizing antibodies raised against one strain to bind and neutralize alternative strains. Certain rare epitopes, however, are required for viral infection and are conserved across strains. Interestingly, neutralizing antibodies against these rare epitopes tend to have long CDR H3 regions. In the case of HIV, long CDR H3s can pierce the viral glycan shield and reach into the conserved epitope on the gp120 spike protein. While long CDR H3 regions in human antibodies are infrequent in the repertoire, cattle routinely produce long (20-40 amino acids) and ultralong (40-70 amino acids) CDR H3 regions that have unique “stalk” and “knob” structural features that protrude far from the antibody surface. Therefore, cattle may be an excellent model organism to identify and define new and conserved neutralizing epitopes in these challenging viruses. Indeed, in preliminary experiments we have found that cattle make a robust and broadly neutralizing antibody response to the HIV gp120 antigen. Here we propose to use the unique cow antibody repertoire to define new conserved neutralizing epitopes on two viruses of great importance to human and animal health, HIV and BVDV. Effective vaccines against both of these viruses have been a major challenge to develop. We will immunize animals against these viruses, generate monoclonal antibodies that neutralize the virus as well as related strains, and molecularly map the antigen-antibody interaction using mutagenesis and structural biology techniques. Definition of new conserved epitopes could lead to engineered epitope-specific vaccines. Thus, the outcomes of this proposal could enable generation of next-generation vaccines for these two viruses, but could also have broad utility in vaccine development against other challenging viruses in the future.