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：
7336809
负责人：
L. Jeannine Brady
金额：
$ 34.11万
依托单位：
UNIVERSITY OF FLORIDA
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-04-15 至 2009-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7336809
关键词：
Accounting Address Adherence Affinity Chromatography Animals Antibodies Antibody Formation Antibody Specificity Antigen Presentation Pathway Antigen-Antibody Complex Antigen-Presenting Cells Antigens Appendix Bacteria Binding Biological Biological Assay Biological Models Biostatistics Core Buffers Cell surface Cells Characteristics Class Complex Condition Consult Core Facility Dendritic Cells Dental caries Development Digestion Endopeptidases 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-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 Personal Satisfaction Predisposition Progress Reports Proteins Proteolysis Proteolytic Processing Protocols documentation Publications Reagent Recombinants Regulation Reporting Research Design Role Sampling Serum Source Specificity Spleen Statistically Significant Stomach Streptococcus adhesin 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）：在上一个资助周期中，我们鉴定了五种针对变形链球菌 P1 表面粘附素的单克隆抗体 (MAb)，当施用抗原作为免疫复合物。该策略对疫苗设计具有影响，因为保护性免疫不一定针对病原体的免疫优势表位，并且可以通过将反应转向次优势表位来很好地改善。结果因所测试的抗 P1 MAb 的不同而异。两种 MAb 导致形成对体外变形链球菌粘附具有更强抑制作用的抗体，另两种则形成抑制性较小的抗体。对一组抗 P1 MAb 识别的表位进行了表征，其中包括复杂的不连续决定簇。来自免疫小鼠的多克隆抗体还可以识别构象表位，其中一些表位似乎比其他表位更具生物学相关性。抗 P1 MAb 抑制变形链球菌粘附的能力与 IgG2a 和 IgG2b 同种型之间存在显着的正相关性，这表明参与类别转换的细胞因子与有益反应发展的相关性。这将作为当前提案的一部分进行探讨。抗 P1 MAb 与细胞相关 P1 的结合改变了其对体外多种蛋白酶的敏感性，表明对蛋白质结构的影响，并表明隐藏表位的暴露以及抗原加工和呈递的变化。还将开展研究来解决这种潜在的免疫调节机制。我们将继续表征免疫小鼠中单克隆抗体介导的体液免疫反应变化，以确定体外抵抗变形链球菌粘附以及体内定植和致龋性的保护的相关性。来自免疫小鼠的样品的免疫测定将利用已知可重建或破坏构象表位的 P1 片段或缺失构建体的组合。迄今为止，尚未在接种疫苗的动物或自然致敏的人类中研究针对构象决定簇的抗 P1 反应。抗 P1 MAb 的免疫调节代表了一种显着改善针对变形链球菌的体液反应的策略，并提供了一种工具来剖析针对这种广泛研究的候选疫苗抗原的有益和非有益抗体。抗 P1 单克隆抗体识别的表位特征可改善或减少有益反应，这将有助于深入了解引发最佳保护性免疫所需的 P1 结构，并有望揭示修饰蛋白质本身以提高其保护性免疫原性的方法，而无需需要用免疫复合物进行免疫。除了这些研究对人类龋齿治疗方法开发的影响之外，充分表征的 P1 抗原和针对它的单克隆抗体代表了一个优秀的模型系统，可以理解免疫调节的后果和潜在的分子机制，并且将引起任何人的普遍兴趣。主动或被动免疫方法。