Boon Adrianus C M, de Mutsert Gerrie, van Baarle Debbie, Smith Derek J, Lapedes Alan S, Fouchier Ron A M, Sintnicolaas Kees, Osterhaus Albert D M E, Rimmelzwaan Guus F
Department of Virology and WHO National Influenza Center, Erasmus MC, Rotterdam, The Netherlands.
J Immunol. 2004 Feb 15;172(4):2453-60. doi: 10.4049/jimmunol.172.4.2453.
In the present study, the recognition of epitope variants of influenza A viruses by human CTL was investigated. To this end, human CD8(+) CTL clones, specific for natural variants of the HLA-B3501-restricted epitope in the nucleoprotein (NP(418-426)), were generated. As determined in (51)Cr release assays and by flow cytometry with HLA-B3501-peptide tetrameric complexes, CTL clones were found to be specific for epitopes within one subtype or cross-reactive with heterosubtypic variants of the epitope. Using eight natural variants of the epitope, positions in the 9-mer important for T cell recognition and involved in escape from CTL immunity were identified and visualized using multidimensional scaling. It was shown that positions 4 and 5 in the 9-mer epitope were important determinants of T cell specificity. The in vivo existence of CD8(+) cells cross-reactive with homo- and heterosubtypic variants of the epitope was further confirmed using polyclonal T cell populations obtained after stimulation of PBMC with different influenza A viruses. Based on the observed recognition patterns of the clonal and polyclonal T cell populations and serology, it is hypothesized that consecutive infections with influenza viruses containing different variants of the epitope select for cross-reactive T cells in vivo.
在本研究中，对人类细胞毒性T淋巴细胞（CTL）识别甲型流感病毒表位变体的情况进行了调查。为此，生成了针对核蛋白中HLA - B3501限制性表位（NP(418 - 426)）天然变体的人类CD8(+) CTL克隆。如通过（51）Cr释放试验以及使用HLA - B3501 - 肽四聚体复合物的流式细胞术所确定的，发现CTL克隆对一个亚型内的表位具有特异性，或者与该表位的异源亚型变体发生交叉反应。使用该表位的八个天然变体，利用多维标度法确定并可视化了9肽中对T细胞识别重要且参与逃避CTL免疫的位置。结果表明，9肽表位中的第4和第5位是T细胞特异性的重要决定因素。使用用不同甲型流感病毒刺激外周血单核细胞（PBMC）后获得的多克隆T细胞群体，进一步证实了与该表位的同源和异源亚型变体发生交叉反应的CD8(+)细胞在体内的存在。基于所观察到的克隆和多克隆T细胞群体的识别模式以及血清学，推测连续感染含有该表位不同变体的流感病毒会在体内选择出交叉反应性T细胞。
