IDENTIFICATION OF ORTHOPOXVIRUS-DERIVED CD8+ T CELL EPITOPES MACAQUES

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 用牛痘病毒接种疫苗诱导强烈的病毒特异性CD 8阳性T细胞应答，其在控制痘病毒感染中起重要作用。 然而，对于作为牛痘特异性CD 8阳性T细胞的靶标的特异性病毒蛋白知之甚少，并且在编码超过200个开放阅读框（ORF）的基因组中鉴定T细胞表位是一项特别具有挑战性的任务。 作为鉴定免疫显性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结合的牛痘肽。 我们合成了294肽衍生自97牛痘ORF，筛选这些肽的识别T细胞从接种疫苗的猕猴和鉴定免疫原性牛痘蛋白。 这些猕猴对多种正痘病毒抗原产生了相对较强的应答：接种疫苗的猕猴识别来自26个不同ORF的29种肽，其中4种肽被所有3只猕猴识别，7种肽被3只猕猴中的2只识别。8个表位不含典型的P3脯氨酸，表明该残基不是Mamu-A*01体内呈递所需的。与其他正痘病毒序列的比较表明，这些表位是高度保守的，存在于牛痘，天花，猴痘。 这些结果表明，病毒特异性CD 8阳性T细胞应答广泛针对多种牛痘蛋白，并且这些T细胞表位的子集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.