Identification and structural definition of H5-specific CTL epitopes restricted by HLA-A*0201 derived from the H5N1 subtype of influenza A viruses
Identification and structural definition of H5-specific CTL epitopes restricted by HLA-A*0201 derived from the H5N1 subtype of influenza A viruses
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DOI：
10.1099/vir.0.016766-0
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发表时间：
2010-04-01
影响因子：
3.8
通讯作者：
Gao, George F.
中科院分区：
文献类型：
--
作者：
Sun, Yeping;Liu, Jun;Gao, George F.
甲型流感病毒的血凝素（HA）糖蛋白是启动抗感染体液免疫的主要抗原;然而，对HA的细胞免疫应答知之甚少。此外，HA衍生的细胞毒性T淋巴细胞（CTL）表位是相对罕见的，相比其他内部基因产物。在此，筛选HA血清型H5蛋白的CTL表位。通过使用计算机预测、体外重折叠和T2细胞结合测定，随后免疫HLA-A2.1/K-b转基因小鼠，显示HLA-A*0201限制性十聚体表位RI-10（H5 HA 205 -214，RLYQNPTTYI）引发稳健的CTL表位特异性应答。此外，RI-10及其变体KI-10（KLYQNPTTYI）也被证明能够在HLA-A*0201阳性患者的外周血单核细胞中诱导比甲型流感病毒显性CTL表位GL-9（GILGFVFTL）更高的CTL表位特异性应答，所述患者已经从H5 N1病毒感染中恢复。此外，RI-10 HLA-A*0201和KI-10 HLA-A*0201复合物的晶体结构分别在2.3和2.2 A分辨率下测定，显示出典型的HLA-A*0201限制性表位。RI-10和KI-10在两种复合物的晶体结构中的抗原呈递凹槽中的构象显示出显著差异，尽管它们的序列几乎相同。这些结果为发现诊断标志物和设计新型流感疫苗提供了启示。
The haemagglutinin (HA) glycoprotein of influenza A virus is a major antigen that initiates humoral immunity against infection; however, the cellular immune response against HA is poorly understood. Furthermore, HA-derived cytotoxic T-lymphocyte (CTL) epitopes are relatively rare in comparison to other internal gene products. Here, CTL epitopes of the HA serotype H5 protein were screened. By using in silico prediction, in vitro refolding and a T2 cell-binding assay, followed by immunization of HLA-A2.1/K-b transgenic mice, an HLA-A*0201-restricted decameric epitope, RI-10 (H5 HA205-214, RLYQNPTTYI), was shown to elicit a robust CTL epitope-specific response. In addition, RI-10 and its variant, KI-10 (KLYQNPTTYI), were also demonstrated to be able to induce a higher CTL epitope-specific response than the influenza A virus dominant CTL epitope GL-9 (GILGFVFTL) in peripheral blood mononuclear cells of HLA-A*0201-positive patients who had recovered from H5N1 virus infection. Furthermore, the crystal structures of RI-10 HLA-A*0201 and KI-10 HLA-A*0201 complexes were determined at 2.3 and 2.2 A resolution, respectively, showing typical HLA-A*0201-restricted epitopes. The conformations of RI-10 and KI-10 in the antigen-presenting grooves in crystal structures of the two complexes show significant differences, despite their nearly identical sequences. These results provide implications for the discovery of diagnostic markers and the design of novel influenza vaccines.