Rotavirus VP6 Specific Human IgA Antibodies

轮状病毒 VP6 特异性人类 IgA 抗体

• 批准号: 7897725
• 负责人: James E Crowe
• 金额: $ 19.38万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-22 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7897725
• 关键词: Animal Model; Antibodies; Antibody Formation; Antiviral Agents; Apical; Attenuated Live Virus Vaccine; Binding; Biological Assay; Bispecific Antibodies; Cells; Cellular biology; Child; Clinical Trials; Complex; Diarrhea; Disease; Endocytosis; Endosomes; Epithelial Cells; Genetic Transcription; Goals; Human; Human Cloning; Human Virus; IgA receptor; IgG1; Immune; Immune response; Immunity; Immunoglobulin A; Intestines; Knowledge; Length; Mediating; Methods; Physiological; Polymeric Immunoglobulin Receptors; Proteins; Recombinant Antibody; Recombinants; Recycling; Role; Rotavirus; Rotavirus Infections; Solid; Specific qualifier value; System; Technology; Testing; Transcript; Vaccines; Viral; Viral Antibodies; Viral Proteins; Virus; Virus Diseases; Work; human monoclonal antibodies; inhibiting antibody; inhibitor/antagonist; killings; meetings; novel; particle; pathogen; polarized cell; polymeric IgA; trafficking; transcytosis; variable region gene

DESCRIPTION (provided by applicant): Mechanisms of immunity to rotavirus, the major cause of dehydrating diarrhea in children, have proven elusive. Despite the fact the live attenuated vaccines induce protection against severe disease, we still don't understand fully how immunity to rotavirus works, or even have rock-solid correlates of immunity from clinical trials. Animal models have suggested a variety of contributing mechanisms. Conceptually, understanding intestinal immunity to rotavirus is very important, because rotavirus represents a prototypical viral infection of humans that is limited to the intestine. If we can understand mucosal immune mechanisms to rotavirus, we will understand a lot more about immunity in the gut that is relevant to a plethora of pathogens. We hypothesize that a dominant mechanism of rotavirus inhibition by the human immune response is rotavirus specific virus protein 6 (VP6) specific antibodies of the IgA isotype. We propose that polymeric VP6-specific IgA antibodies bind to double layered particles inside infected intestinal cells and inhibit viral transcription. This mechanism has never really been tested in clinical trials as a correlate or mechanism, because VP6-specific antibodies will not neutralize virus in a conventional inhibitory assay, and only IgA antibodies could mediate the effect during transcytosis in polarized cells. We have isolated a large panel of hundreds of human VP6-specific human monoclonal antibodies, and shown that the immunodominant antibody response of humans specifies a set of antibodies that bind to double layered particles at the point of five-fold symmetry, inhibiting egress of viral transcripts from the transcriptionally active particle. The goal of this application is to show 1) that polymeric IgA forms of these antibodies inhibit rotavirus in a physiological manner during basolateral to apical transcytosis, 2) that the apical recycling endosome is a critical part of the transycytotic mechanism related to inhibition, and 3) that we can develop an artificial bispecific antibody scFv construct that can deliver antiviral antibodies to the cell via the IgA receptor (pIgR) as a means of developing biologic inhibitors for use against any intracellular intestinal pathogen. The work in this application will study the role of a particular type of antibodies in the gut (IgA antibodies) on immunity to rotavirus, the most common cause of severe diarrhea in children. The work seeks to show that these special antibodies bind to "inside" parts of the virus when the virus and antibodies meet inside of infected cells in the gut. If we show that this method of killing virus does inhibit rotavirus, we will understand how rotavirus antibodies and vaccines work and we can use this knowledge to create vaccines that work in a similar manner against other pathogens.

描述(由申请人提供)：轮状病毒的免疫机制被证明是难以捉摸的，轮状病毒是儿童脱水腹泻的主要原因。尽管减毒活疫苗对严重疾病有保护作用，但我们仍然不完全了解轮状病毒的免疫是如何发挥作用的，甚至没有从临床试验中获得坚如磐石的免疫相关性。动物模型显示了多种致病机制。从概念上讲，了解对轮状病毒的肠道免疫是非常重要的，因为轮状病毒代表了一种仅限于肠道的人类典型病毒感染。如果我们能够了解轮状病毒的粘膜免疫机制，我们将更多地了解肠道中与过多病原体相关的免疫。我们假设，轮状病毒抑制人类免疫反应的主要机制是轮状病毒特异性病毒蛋白6(VP6)特异性抗体的IgA同型。我们认为，多聚体VP6特异性IgA抗体结合到受感染的肠道细胞内的双层颗粒上，并抑制病毒转录。这种机制从来没有真正在临床试验中作为一种相关性或机制进行测试，因为VP6特异性抗体不会在传统的抑制试验中中和病毒，而且只有IgA抗体可以在极化细胞的跨细胞作用中发挥作用。我们已经分离了一大批数百种人类VP6特异性的人类单抗，并表明人类的免疫主导抗体反应指定了一组抗体，这些抗体在五重对称点与双层颗粒结合，抑制病毒转录产物从转录活性颗粒中流出。本申请的目的是证明1)这些抗体的聚合IgA形式在顶端跨细胞溶解过程中以生理方式抑制轮状病毒，2)顶端循环内小体是与抑制相关的跨细胞机制的关键部分，以及3)我们可以开发一种人造双特异性抗体scFv结构，它可以通过IgA受体(PIgR)将抗病毒抗体输送到细胞内，作为一种开发用于对抗任何细胞内病原体的生物抑制剂的手段。这项应用中的工作将研究肠道中一种特殊类型的抗体(IgA抗体)对轮状病毒免疫的作用，轮状病毒是儿童严重腹泻的最常见原因。这项工作试图证明，当病毒和抗体在肠道中的受感染细胞内部相遇时，这些特殊的抗体会与病毒的“内部”部分结合。如果我们证明这种杀死病毒的方法确实抑制了轮状病毒，我们就会了解轮状病毒抗体和疫苗是如何工作的，我们可以利用这一知识来创造出以类似方式对抗其他病原体的疫苗。