Lu Jun, Higashimoto Yuichiro, Appella Ettore, Celis Esteban
Department of Immunology and Cancer Center, Mayo College of Medicine, Mayo Clinic, Rochester, MN 55905, USA.
J Immunol. 2004 Apr 1;172(7):4575-82. doi: 10.4049/jimmunol.172.7.4575.
We describe in this study a strategy to produce synthetic vaccines based on a single polypeptide capable of eliciting strong immune responses to a combination CTL and Th epitopes with the purpose of treating malignancies or preventing infectious diseases. This strategy is based on the capacity of Trojan Ags to deliver exogenous Ags into the intracellular compartments, where processing into MHC-binding peptides takes place. Our previous work demonstrated that Trojan Ags containing a CTL epitope localized to intracellular compartments, where MHC class I-binding peptides were generated in a TAP-independent fashion by the action of various exopeptidases and the endopeptidase furin. In this study, we report that Trojan Ags containing several CTL epitopes joined via furin-sensitive linkers generated all of the corresponding MHC class I-binding peptides, which were recognized by CTL. However, Trojan Ags prepared with furin-resistant linkers failed to produce the MHC class I-binding peptides. We also present data indicating that Trojan Ags bearing both CTL and Th epitopes can generate the corresponding MHC class I- and II-binding peptides, which are capable of stimulating T cell responses. Most significantly, in vivo vaccination of mice with a single injection of multiepitope Trojan Ags resulted in strong CTL and Th responses that translated into significant antitumor responses in a model of malignant melanoma. The overall results indicate that Trojan Ags prepared with furin-sensitive linkers are ideal candidates for producing synthetic multiepitope vaccines for the induction of CTL and Th responses that could be used against a variety of diseases, including cancer.
我们在本研究中描述了一种生产合成疫苗的策略，该疫苗基于一种单一多肽，能够引发针对CTL和Th表位组合的强烈免疫反应，目的是治疗恶性肿瘤或预防传染病。该策略基于特洛伊抗原（Trojan Ags）将外源性抗原递送至细胞内区室的能力，在该区室内会加工成与MHC结合的肽段。我们之前的工作表明，含有CTL表位的特洛伊抗原定位于细胞内区室，在该区室内，通过各种外肽酶和内肽酶弗林蛋白酶（furin）的作用，以不依赖TAP的方式生成与MHC I类结合的肽段。在本研究中，我们报告称，含有多个通过弗林蛋白酶敏感连接子连接的CTL表位的特洛伊抗原产生了所有相应的与MHC I类结合的肽段，这些肽段可被CTL识别。然而，用弗林蛋白酶抗性连接子制备的特洛伊抗原未能产生与MHC I类结合的肽段。我们还提供数据表明，同时带有CTL和Th表位的特洛伊抗原能够产生相应的与MHC I类和II类结合的肽段，这些肽段能够刺激T细胞反应。最重要的是，在恶性黑色素瘤模型中，单次注射多表位特洛伊抗原对小鼠进行体内疫苗接种可导致强烈的CTL和Th反应，并转化为显著的抗肿瘤反应。总体结果表明，用弗林蛋白酶敏感连接子制备的特洛伊抗原是生产用于诱导CTL和Th反应的合成多表位疫苗的理想候选物，可用于对抗包括癌症在内的多种疾病。
