Alexander Jeff, Oseroff Carla, Dahlberg Carol, Qin Mingsheng, Ishioka Glenn, Beebe Melanie, Fikes John, Newman Mark, Chesnut Robert W, Morton Phillip A, Fok Kam, Appella Ettore, Sette Alessandro
Epimmune, San Diego, CA 92121, USA.
J Immunol. 2002 Jun 15;168(12):6189-98. doi: 10.4049/jimmunol.168.12.6189.
Proteins are generally regarded as ineffective immunogens for CTL responses. We synthesized a 100-mer decaepitope polypeptide and tested its capacity to induce multiple CD8(+) IFN-gamma and Th lymphocyte (HTL) responses in HLA transgenic mice. Following a single immunization in the absence of adjuvant, significant IFN-gamma in vitro recall responses were detected for all epitopes included in the construct (six A2.1-, three A11-restricted CTL epitopes, and one universal HTL epitope). Immunization with truncated forms of the decaepitope polypeptide was used to demonstrate that optimal immunogenicity was associated with a size of at least 30-40 residues (3-4 epitopes). Solubility analyses of the truncated constructs were used to identify a correlation between immunogenicity for IFN-gamma responses and the propensity of these constructs to form particulate aggregates. Although the decaepitope polypeptide and a pool of epitopes emulsified in IFA elicited similar levels of CD8(+) responses using fresh splenocytes, we found that the decaepitope polypeptide more effectively primed for in vitro recall CD8(+) T cell responses. Finally, immunogenicity comparisons were also made between the decaepitope polypeptide and a corresponding gene encoding the same polypeptide delivered by naked DNA immunization. Although naked DNA immunization induced somewhat greater direct ex vivo and in vitro recall responses 2 wk after a single immunization, only the polypeptide induced significant in vitro recall responses 6 wk following the priming immunization. These studies support further evaluation of multiepitope polypeptide vaccines for induction of CD8(+) IFN-gamma and HTL responses.
蛋白质通常被认为是诱导细胞毒性T淋巴细胞（CTL）反应的无效免疫原。我们合成了一种100聚体的十表位多肽，并测试了其在HLA转基因小鼠中诱导多种CD8(+)干扰素-γ和辅助性T淋巴细胞（HTL）反应的能力。在无佐剂的情况下进行单次免疫后，针对构建体中包含的所有表位（六个A2.1限制性、三个A11限制性CTL表位和一个通用HTL表位）检测到显著的体外干扰素-γ回忆反应。用十表位多肽的截短形式进行免疫，以证明最佳免疫原性与至少30 - 40个残基（3 - 4个表位）的大小相关。对截短构建体的溶解性分析用于确定干扰素-γ反应的免疫原性与这些构建体形成颗粒聚集体倾向之间的相关性。尽管十表位多肽和在弗氏不完全佐剂中乳化的表位池使用新鲜脾细胞引发了相似水平的CD8(+)反应，但我们发现十表位多肽在体外回忆CD8(+) T细胞反应的启动方面更有效。最后，还对十表位多肽与通过裸DNA免疫递送的编码相同多肽的相应基因进行了免疫原性比较。尽管裸DNA免疫在单次免疫后2周诱导了略高的直接体外和体外回忆反应，但只有多肽在初次免疫后6周诱导了显著的体外回忆反应。这些研究支持进一步评估多表位多肽疫苗诱导CD8(+)干扰素-γ和HTL反应的效果。
