MHC tetramers for epitopes of B anthracis PA

描述（由申请人提供）：美国已承诺为大量人接种炭疽疫苗。然而，目前炭疽疫苗的局限性被广泛承认，并正在努力改进疫苗配方。我们将建立炭疽疫苗接种反应的生物标记和预测因子，长期临床目标是设计更安全和更有效的疫苗。为了实现这一目标，我们将开发新的人类II类MHC四聚体，其鉴定对炭疽杆菌保护性抗原（BAPA）特异的抗原特异性CD 4 + T细胞。炭疽疫苗接种后四聚体阳性T细胞的定量和表型将作为细胞免疫的指标进行评价。 具体目标是： 目标1.目的：根据HLA Ⅱ类抗原结合情况，确定炭疽芽孢杆菌保护性抗原（BAPA）的免疫优势表位，并为CD 4 T细胞所识别。 目标二。利用可溶性HLA-BAPA四聚体定量检测炭疽疫苗接种后CD 4 T细胞的免疫应答。 基于选择对应于T细胞识别一组限制性BAPA表位的肽，将产生并评价涵盖大多数流行的人II类单倍型的四聚体。本项目的MHC-肽结合试验、四聚体生产和检测方法以及表位扫描技术均经过验证，并且使用转基因鼠替代物对BAPA的T细胞应答的初步数据表明，接种疫苗后成功检测到应答抗原特异性群体。

DESCRIPTION (provided by applicant): A commitment has been made in the USA to vaccinate large numbers of persons against anthrax. However, limitations of the current anthrax vaccine are widely acknowledged, and efforts are underway to improve the vaccine formulation. We will create biological markers and predictors of the response to anthrax vaccination, with the long-term clinical goal of designing safer and more effective vaccines. To achieve this objective, we will develop novel human class II MHC tetramers which identify antigen-specific CD4+ T cells specific for bacillus anthrax Protective Antigen (BAPA). Quantitation and phenotyping of the tetramer-positive T cells following anthrax vaccination will be evaluated as an indicator of cellular immunity. The Specific Aims are: Aim 1. To identify immunodominant epitopes of bacillus anthrax Protective Antigen (BAPA) based on HLA class II binding and recognized by CD4 T cells which are capable of eliciting robust immunity. Aim 2. To use soluble HLA-BAPA tetramers to quantify the CD4 T cell response to anthrax vaccination. Tetramers will be produced and evaluated which encompass most of the prevalent human class II haplotypes, based on selection of peptides corresponding to T cell recognition of a restricted set of BAPA epitopes. MHC-peptide binding assays, tetramer production and testing methods, and epitope scanning technologies for this project are all validated, and preliminary data using transgenic murine surrogates for the T cell response to BAPA demonstrate successful detection of the responding antigen-specific population following vaccination.