Synergistic combinations of chimeric anti-SEB: Engineering anti-toxins

嵌合抗SEB的协同组合：工程抗毒素

• 批准号: 7371194
• 负责人: Richard A Goldsby
• 金额: $ 21.91万
• 依托单位: AMHERST COLLEGE
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-01 至 2010-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7371194
• 关键词: Adverse effects; Antibodies; Antigen-Presenting Cells; Behavior; Binding; Binding Sites; Biological; Blocking Antibodies; Clinical; Collection; Derivation procedure; Disease; Engineering; Epitopes; Food Poisoning; Histocompatibility Antigens Class II; Human; Human Anti-Mouse Antibody; Hybridomas; IgG1; Immunoglobulin Constant Region; Immunoglobulin Variable Region; Incidence; Individual; Ingestion; Intoxication; Libraries; Life; Light; MHC Class II Genes; Monoclonal Antibodies; Mus; Numbers; Property; Prophylactic treatment; Range; Reaction; Screening procedure; Site; Staphylococcal Enterotoxin B; Superantigens; T-Cell Proliferation; T-Lymphocyte; Testing; Therapeutic; Toxic Shock Syndrome; Toxin; Work; chimeric antibody; clinical application; cytokine; design; expectation; experience; member; neutralizing antibody; prevent; progenitor; staphylococcal enterotoxin; tool

DESCRIPTION (provided by applicant): Synergistic combinations of chimeric anti-SEB: Engineering anti-toxins Staphylococcal enterotoxin B (SEB) is a superantigen that causes food poisoning and toxic shock syndrome. The biological activity of SEB arises from its ability to nonspecifically activate large numbers of T cells by simultaneously binding to the MHC-II on antigen presenting cells and TCRs of T cells belonging to a subset of V2 subfamilies. Antibodies can neutralize these toxins by blockading either of these sites. These studies arise from the hypothesis that combinations of antibodies targeting different and spatially separated neutralizing epitopes will act synergistically. The antibodies for this study will be obtained by screening a library of anti-SEB hybridomas generated from Balb/C mice immunized with native SEB. The screening strategy will identify two groups of neutralizing antibodies, one of which recognizes epitopes in the TCR- binding site of SEB and a second group that reacts with determinants in the MHC-II binding site of the toxin. Combinations of noncrossreactive members of each of these groups will be tested to determine which act synergistically. The VH and VL regions of each of the members of the most potent neutralizing combination will be cloned and grafted to sequences encoding the human IgG1CH (mouse VH ) and human Ig:CL (mouse VL ). The chimerized human-mouse antibodies which would be expected to produce much less HAMA reaction in clinical applications will be evaluated by comparing the neutralization activity of the chimeric set and its members with that of its mouse counterparts. The proposal has the following specific aims: 1. Generate neutralizing antibodies against the MHC binding site of SEB and derive neutralizing antibodies specific for the TCR beta binding site. 2. Identify neutralizing antibodies specific for different epitopes of SEB and determine if combinations of these antibodies synergistically inhibit SEB. 3: Graft the VH and VL domains of each member of the most potent sets of synergistically acting neutralizing antibodies onto human CH and CL frameworks. Combinations of antibodies that synergistically inhibit SEB may have two important practical advantages should they see application in a clinical setting. First, it should be less expensive because much smaller amounts would be needed than with single monoclonal antibodies. Second, the ability to achieve an equivalent therapeutic result with smaller amounts of antibody should decrease the incidence and intensity of side effects. Staphylococcal enterotoxin B (SEB) can cause food poisoning and toxic shock syndrome. Antibodies can neutralize SEB and this study is guided by the hypothesis that combinations of mouse monoclonal antibodies targeting different neutralizing sites will act synergistically. Chimeric human-mouse forms of the most effective combinations will be engineered to produce antibodies that will be better tolerated in humans.

描述（由申请方提供）：嵌合抗SE B的协同组合：工程抗毒素葡萄球菌肠毒素B（SE B）是一种引起食物中毒和中毒性休克综合征的超抗原。SEB的生物学活性源于其通过同时结合抗原呈递细胞上的MHC-II和属于V2亚家族亚组的T细胞的TCR而非特异性活化大量T细胞的能力。抗体可以通过阻断这两个位点中的任何一个来中和这些毒素。这些研究源于这样的假设，即靶向不同和空间上分离的中和表位的抗体组合将协同作用。本研究的抗体将通过筛选由天然SEB免疫的Balb/C小鼠产生的抗SEB杂交瘤文库来获得。筛选策略将鉴定两组中和抗体，其中一组识别SEB的TCR结合位点中的表位，第二组与毒素的MHC-II结合位点中的决定簇反应。将测试这些组中的每一个的非交叉反应性成员的组合，以确定哪一个协同作用。将最有效中和组合的每个成员的VH和VL区克隆并移植到编码人IgG 1 CH（小鼠VH）和人IG：CL（小鼠VL）的序列上。预期在临床应用中产生少得多的HAMA反应的嵌合的人-小鼠抗体将通过比较嵌合组及其成员与其小鼠对应物的中和活性来评估。该提案有以下具体目标：1.产生针对SEB的MHC结合位点的中和抗体，并衍生针对TCR β结合位点的特异性中和抗体。2.鉴定对SEB的不同表位特异的中和抗体，并确定这些抗体的组合是否协同抑制SEB。第三章：将最有效的协同作用中和抗体组的每个成员的VH和VL结构域移植到人CH和CL框架上。协同抑制SEB的抗体的组合可以具有两个重要的实际优点，如果它们在临床环境中应用的话。首先，它应该更便宜，因为需要的量比单克隆抗体少得多。第二，用较少量的抗体实现等效治疗结果的能力应降低副作用的发生率和强度。葡萄球菌肠毒素B（SE B）可引起食物中毒和中毒性休克综合征。抗体可以中和SEB，并且本研究由以下假设指导：靶向不同中和位点的小鼠单克隆抗体的组合将协同作用。最有效组合的嵌合人-小鼠形式将被工程化以产生在人类中更好耐受的抗体。