Peptide vaccine for killer T cell induction against hepatitis C virus

在丙型肝炎病毒（HCV）蛋白中已经确定了几个细胞毒性T淋巴细胞（CTL）表位。CTL可能在控制HCV感染中发挥重要作用。在这里，我们确定了一个高度保守的抗原位点，在HCV的核心识别的小鼠和人的CTL。脾细胞从小鼠免疫与重组痘苗病毒表达的HCV核心基因在体外再刺激与11肽的核心蛋白。来自H-2^d小鼠的CTL对单个16残基合成肽（HCV 129-144）应答。这种保守的表位由鼠I类主要组织相容性分子（H-2D ^d）呈递给通过使用表达D^d、L^d或K^d的转染子绘制的常规CD 4 ^-CD 8 ^+ CTL，但在H-2 ^b限制性CTL中未观察到。该表位定位于LMGYIPLVGA十肽，两个HCV阳性患者的CTL均能识别该16个氨基酸残基的肽段，而所有阴性供体的CTL均不能识别。两例HLA-A2阳性急性白血病患者的CTL ...更多信息 慢性丙型肝炎病毒识别由HLA-A2呈递的肽的9个残基片段（DLMGYIPLV），该片段含有HLA-A2结合基序，仅延伸出鼠表位1个残基。因此，这种保守的肽，与鼠CTL和人CTL与一个非常普遍的HLA I类分子，可能是一个有价值的组成部分的HCV疫苗对广泛的HCV分离株。这项研究表明，在人类研究之前，在小鼠中筛选CTL表位可能是有用的。在动物模型中的疫苗开发取决于识别人类T细胞所见表位的能力。在这项工作中，我们表明，在转基因小鼠表达人类HLA-A2.1的CTL反应前瞻性地预测相同的11个丙型肝炎病毒（HCV）结构蛋白衍生肽，表达HLA-A2.1结合的序列基序，这实际上是由人类A2. 1限制性CTL识别。CTL还识别内源性表达这些蛋白质的靶标。来自HCV感染患者的人CTL，通过使用相同的肽进行测试，揭示了几乎相同的反应库。高度保守的HCV核心肽是最具免疫原性的，并且可能是针对HLA-A2阳性患者中的广泛HCV分离株的疫苗的有价值的组分。这些结果表明，尽管存在物种差异，但T细胞库具有足够的可塑性，当相同的I类MHC分子呈递肽时，可以产生类似的反应。因此，HLA分子在确定哪些肽被CTL识别中起主要作用。这种转基因小鼠模型对于研究HLA限制性CTL决定簇和设计潜在的HCV疫苗具有重要意义。少

Several cytotoxic T-lymphocyte (CTL) epitopes have been defined in hepatitis C virus (HCV) proteins. CTL may play an important role in the control of infection by HCV.Here, we identify a highly conserved antigenic site in the HCV core recognized by both murine and human CTL.Spleen cells from mice immunized with a recombinant vaccinia virus expressing the HCV core gene were restimulated in vitro with 11 peptides from the core protein. CTL from H-2^d mice responded to a single 16-residue synthetic peptide (HCV 129-144). This conserved epitope was presented by a murine class I major histocompatibility molecule (H-2D^d) to conventional CD4^- CD8^+ CTL mapped by using transfectants expressing D^d, L^d, or K^d, but was not seen by CTL restricted by H-2^b. The murine epitope was mapped to the decapeptide LMGYIPLVGA.The same 16-residue peptide was recognized by CTL from two HCV-seropositive patients but not by CTL from any scronegative donors. CTL from two HLA-A2-positive patients with acute a … More nd chronic hepatitides C recognized a 9-residue fragment (DLMGYIPLV) of the peptide presented by HLA-A2 and containing an HLA-A2-binding motif, extending only 1 residue beyond the murine epitope. Therefore, this conserved peptide, seen with murine CTL and human CTL with a very prevalent HLA class I molecule, may be a valuable component of an HCV vaccine against a broad range of HCV isolates. This study demonstrates that the screening for CTL epitopes in mice prior to human study may be useful.Vaccine development in animal models depends on ability to recognize epitopes seen by human T cells. In this work, we show that CTL responses in transgenic mice expressing human HLA-A2.1 prospectively predict the same four of 11 hepatitis C virus (HCV) structural protein-derived peptides, expressing a sequence motif for HLA-A2.1 binding, that are actually recognized by human A2.1-restricted CTLs. The CTLs also recognized targets endogenously expressing these proteins. Human CTLs from HCV-infected patients, tested by using the same peptides, revealed a virtually identical response repertoire. A highly conserved HCV core peptide was the most immunogenic, and may-be a valuable component of a vaccine against a broad range of HCV isolates in HLA-A2-positive patients. These results suggest that, in spite of species differences, the T cell repertoire is plastic enough to allow a similar response when the same class I MHC molecule is presenting the peptide. Thus, the HLA molecule plays the primary role in determining which peptides are recognized by CTLs. This transgenic mouse model is important for the study of HLA-restricted CTL determinants and for an approach to design a potential HCV vaccine. Less