IDENTIFICATION OF ORTHOPOXVIRUS-DERIVED CD8+ T CELL EPITOPES MACAQUES

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 痘苗病毒疫苗能诱导强烈的病毒特异性CD8阳性T细胞反应，在控制痘病毒感染中发挥重要作用。然而，对作为痘苗病毒特异性CD8阳性T细胞靶标的病毒蛋白知之甚少，在编码200多个开放阅读框架(ORF)的基因组中识别T细胞表位是一项特别具有挑战性的任务。作为鉴定免疫优势痘病毒蛋白的一种方法，我们使用了一种算法来预测能够与常见的猕猴MHC I类分子MAMU-A*01结合的牛痘多肽。我们从97个痘苗病毒ORF中合成了294个多肽，对这些多肽进行了筛选，以供免疫猕猴的T细胞识别，并鉴定了免疫原性牛痘蛋白。这些猕猴对多种正痘病毒抗原产生了较强的反应：接种疫苗的猕猴识别来自26个不同ORF的29个肽，其中4个肽可被所有3只猕猴识别，7个肽可被3只猕猴中的2只识别。有8个表位不包含典型的P3脯氨酸，表明该残基不是MAMU-A*01体内呈递所必需的。与其他正痘病毒序列的比较表明，这些表位高度保守，存在于牛痘、天花和猴痘中。这些结果表明，病毒特异性的CD8阳性T细胞反应广泛地针对多种痘苗病毒蛋白，并且这些T细胞表位的一部分在正痘病毒中高度保守。与艾滋病有关。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Vaccination with vaccinia virus induces a vigorous virus-specific CD8-positive T cell response that plays an important role in control of poxvirus infection. However, little is known about the specific viral proteins that are serve as targets of vaccinia-specific CD8-positive T cells, and identification of T cell epitopes in a genome that encodes over 200 open reading frames (ORFs) is a particularly challenging task. As one approach to the identification of immunodominant poxvirus proteins, we used an algorithm for the prediction of vaccinia peptides able to bind to the common macaque MHC class I molecule Mamu-A*01. We synthesized 294 peptides derived from 97 vaccinia ORFs, screened these peptides for recognition by T cells from vaccinated macaques and identified immunogenic vaccinia proteins. These macaques developed relatively strong responses against multiple orthopoxvirus antigens: vaccinated macaques recognized 29 peptides from 26 different ORFs with 4 peptides recognized by all 3 macaques and 7 peptides recognized by 2 of 3 macaques. Eight epitopes did not contain the canonical P3 proline, suggesting that this residue is not required for in vivo presentation by Mamu-A*01. Comparison with other orthopoxvirus sequences revealed that these epitopes were highly conserved and present in vaccinia, variola, and monkeypox. These results suggest that the virus-specific CD8-positive T cell response is broadly directed against multiple vaccinia proteins and that a subset of these T cell epitopes are highly conserved among orthopoxviruses. AIDS related.