Immunomodulation by exogenous streptococcal antibody

外源性链球菌抗体的免疫调节

基本信息

批准号：
7934216
负责人：
L. Jeannine Brady
金额：
$ 10万
依托单位：
UNIVERSITY OF FLORIDA
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-03-08 至 2011-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7934216
关键词：
Accounting Address Adherence Affinity Chromatography Animals Antibodies Antibody Formation Antibody Specificity Antigen Presentation Pathway Antigen-Antibody Complex Antigen-Presenting Cells Antigens Bacteria Bacterial Adhesins Binding Biological Biological Assay Biological Models Biostatistics Core Buffers Cell surface Cells Characteristics Complex Consult Core Facility Dendritic Cells Dental caries Development Digestion Enzyme-Linked Immunosorbent Assay Epitopes Excision Experimental Designs Fab Immunoglobulins Ficain Florida Funding Harvest Histocompatibility Antigens Class II Human Immune response Immunity Immunization Immunization Schedule Immunoassay Immunoglobulin A Immunoglobulin Class Switching Immunoglobulin G Immunoglobulins In Vitro Inbred BALB C Mice Individual Infection Inguinal lymph node group Interferon Type II Interleukin-10 Interleukin-12 Interleukin-2 Interleukin-4 Interleukin-5 Interleukin-6 Intubation Lead Life Light MALDI-TOF Mass Spectrometry Measures Mediating Methods Modeling Molecular Molecular Conformation Monoclonal Antibodies Mus N-chlorosuccinimide Papain Passive Immunization Pepsin A Peptide Hydrolases Peptides Predisposition Progress Reports Proteins Proteolysis Proteolytic Processing Protocols documentation Publications Reagent Recombinants Regulation Reporting Research Design Role Sampling Serum Source Specificity Spleen Stomach Streptococcus mutans Structure Surface Surface Plasmon Resonance System T-Cell Proliferation T-Lymphocyte T-Lymphocyte Epitopes Testing Therapeutic Thymidine Universities Vaccinated Vaccine Antigen Vaccine Design Variant Western Blotting Work antigen processing austin base chemokine clinically relevant cytokine dosage human salivary agglutinin immunogenicity immunoregulation improved in vivo insight interest intraperitoneal pathogen polyclonal antibody polypeptide protein structure reconstitution research study response tool uptake

项目摘要

DESCRIPTION (provided by applicant): During the previous funding cycle we identified five monoclonal antibodies (MAbs) against the P1 surface adhesin of Streptococcus mutans that redirect the humoral immune response in mice in terms of quantity, specificity and isotype of elicited antibodies when administered with the antigen as an immune complex. This strategy has implications for vaccine design in that protective immunity is not necessarily directed at immunodomiant epitopes of pathogens and could well be improved by shifting a response toward subdominant epitopes. Results varied depending on the anti-P1 MAb tested. Two MAbs resulted in formation of antibodies more inhibitory of S. mutans adherence in vitro and two others of less inhibitory antibodies. Epitopes recognized by a panel of anti-P1 MAbs were characterized and include complex discontinuous determinants. Polyclonal antibodies from immunized mice also recognize conformational epitopes, some of which appear more biologically relevant than others. Significant positive correlations were demonstrated between the ability of anti-P1 MAbs to inhibit S. mutans adherence and IgG2a and IgG2b isotypes suggesting the relevance of cytokines involved in class switching in the development of beneficial responses. This will be explored as part of the current proposal. Binding of an anti-P1 MAb to cell-associated P1 altered its susceptibility to numerous proteases in vitro indicating an influence on protein structure and suggesting exposure of cryptic epitopes and changes in antigen processing and presentation. Studies to address this potential mechanism of immunomodulation will also be undertaken. We will continue to characterize MAb-mediated changes in humoral immune responses in immunized mice to identify correlates of protection against S. mutans adherence in vitro and colonization and cariogenicity in vivo. Immunoassays of samples from immunized mice will utilize combinations of P1 segments, or deletion constructs, known to reconstitute or destroy conformational epitopes. The anti-P1 response against conformational determinants has not been studied to date in vaccinated animals or naturally sensitized humans. Immunomodulation by anti-P1 MAbs represents a strategy to significantly improve the humoral response against S. mutans and provides a tool to dissect beneficial and non-beneficial antibodies against this widely studied candidate vaccine antigen. The characterization of epitopes recognized by anti-P1 MAbs that improve or decrease the beneficial response will provide insight into the structure of P1 required to elicit optimal protective immunity and is expected to shed light on ways to modify the protein itself to improve its protective immunogenicity without the need to immunize with immune complexes. Beyond the impact of these studies on development of a therapeutic approach against human dental caries, the well-characterized P1 antigen and MAbs against it represent an excellent model system to understand the consequences and underlying molecular mechanisms of immunomodulation and would be of general interest for any active or passive immunization approach.

描述（由申请人提供）：在先前的资金周期中，我们确定了针对链球菌突变的P1表面粘附素的五种单克隆抗体（MAB），这些抗体的体液反应以数量，特异性和引起的抗体的抗体抗体为抗抗体时，将小鼠的体液免疫反应重定向。该策略对疫苗的设计具有影响，因为保护性免疫不一定针对病原体的免疫症状表位，并且可以通过将反应转换为亚较大表位来改善。结果取决于测试的抗P1 mAb。两个mAb导致形成抗体的体外抑制性链球菌的抑制作用，而另两种抑制性抗体较少的抗体。表征了由一组抗P1 mAb识别的表位，包括复杂的不连续决定因素。免疫小鼠的多克隆抗体也识别构象表位，其中一些表现比其他抗体更重要。抗P1 mAb抑制链球菌粘附性链球菌的能力与IgG2a和IgG2b同种型之间表明了显着的阳性相关性，这表明细胞因子在类别切换中与有益反应的发展相关。这将作为当前建议的一部分进行探讨。抗P1 mAb与细胞相关的P1的结合改变了其对众多蛋白酶在体外的敏感性，表明对蛋白质结构有影响，并表明暴露于隐性表位和抗原加工和表现的变化。还将进行解决这种免疫调节的潜在机制的研究。我们将继续表征免疫小鼠中MAB介导的体液免疫反应的变化，以鉴定在体外依从性诱变的保护链球菌的相关性，并在体内定植和殖民地性。免疫小鼠样品的免疫测定将利用P1段或缺失构建体的组合，已知可以重新构建或破坏构象表位。迄今为止，在接种疫苗的动物或自然敏化的人类中，尚未研究针对构象决定因素的抗P1反应。抗P1 mAB的免疫调节代表了一种显着改善对链球菌的体液反应的策略，并提供了一种针对这种广泛研究的候选疫苗抗原的有益和非脱皮抗体的工具。通过抗P1 mAB识别的表位以改善或减少有益反应的表位，将洞悉引起最佳保护性免疫所需的P1结构，并有望阐明修饰蛋白质本身以改善其保护性免疫原性的方法，而无需免疫复合物免疫复合物。除了这些研究对针对人类龋齿的治疗方法发展的影响之外，对其进行良好特征的P1抗原和MABS是一种出色的模型系统，可以理解免疫调节的后果和潜在的分子机制，并且对于任何主动或被动免疫方法都将具有广泛的利益。