Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, 986395 Nebraska Medical Center, Omaha, NE 68198-6395, United States.
Vaccine. 2011 Aug 11;29(35):5904-10. doi: 10.1016/j.vaccine.2011.06.070. Epub 2011 Jul 1.
Vaccines to large B cell lymphoma were made by the covalent attachment of an epitope from the gp70 glycoprotein (SSWDFITV) to the N-termini of the conformationally biased, response-selective C5a agonists EP54 (YSFKPMPLaR) and EP67 (YSFKDMP(MeL)aR). Syngeneic Balb/c mice were immunized with these EP54/EP67-containing vaccines and challenged with a lethal dose of the highly liver metastatic and gp70-expressing lymphoma cell line RAW117-H10 to evaluate the ability of these vaccines to induce protective immune outcomes. All mice immunized with SSWDFITVRRYSFKPMPLaR (Vaccine 2) and SSWDFITVRRYSFKDMP(MeL)aR (Vaccine 3) were protected to a lethal challenge of RAW117-H10 lymphoma (>170 days survival) and exhibited no lymphoma infiltration or solid tumor nodules in the liver relative to unvaccinated controls (<18 days survival). Vaccines 2 and 3 contained the protease-sensitive double-Arg (RR) linker sequence between the epitope and the EP54/EP67 moieties in order to provide a site for intracellular proteases to separate the epitope from the EP54/EP67 moieties once internalized by the APC and, consequently, enhance epitope presentation in the context of MHC I/II. These protected mice exhibited an immune outcome consistent with increased involvement of CD8(+) and/or CD4(+) T lymphocytes relative to controls and mice that did not survive or showed low survival rates as with Vaccines 1 and 4, which lacked the RR linker sequence. CD8(+) T lymphocytes activated in response to Vaccines 2 and 3 express cytotoxic specificity for gp70-expressing RAW117-H10 lymphoma cells, but not antigen-irrelevant MDA-MB231A human breast cancer cells. Results are discussed against the backdrop of the ability of EP54/EP67 to selectively target antigens to and activate C5a receptor-bearing antigen presenting cells and the prospects of using such vaccines therapeutically against lymphoma and other cancers.
针对大 B 细胞淋巴瘤的疫苗是通过将糖蛋白 gp70 上的表位（SSWDFITV）与构象偏倚、应答选择性 C5a 激动剂 EP54（YSFKPMPLaR）和 EP67（YSFKDMP（MeL）aR）的 N 端进行共价连接而制成的。将这些含有 EP54/EP67 的疫苗注射到同基因 Balb/c 小鼠体内，并对其进行致死剂量的具有高度肝转移和 gp70 表达的淋巴瘤细胞系 RAW117-H10 的攻击，以评估这些疫苗诱导保护性免疫应答的能力。所有用 SSWDFITVRRYSFKPMPLaR（疫苗 2）和 SSWDFITVRRYSFKDMP（MeL）aR（疫苗 3）免疫的小鼠都能抵抗 RAW117-H10 淋巴瘤的致死性攻击（>170 天存活），与未接种疫苗的对照组相比（<18 天存活），肝脏中没有淋巴瘤浸润或实体瘤结节。疫苗 2 和 3 在表位和 EP54/EP67 部分之间含有蛋白酶敏感的双 Arg（RR）连接序列，以便为细胞内蛋白酶提供一个位点，一旦 APC 内化了该连接序列，就可以将表位与 EP54/EP67 部分分离，从而增强 MHC I/II 背景下的表位呈递。这些受保护的小鼠表现出的免疫结果与对照小鼠和未存活或存活率低的小鼠（如缺乏 RR 连接序列的疫苗 1 和 4）相比，CD8(+)和/或 CD4(+)T 淋巴细胞的参与度增加。对疫苗 2 和 3 作出反应的 CD8(+)T 淋巴细胞对表达 gp70 的 RAW117-H10 淋巴瘤细胞具有细胞毒性特异性，但对与抗原无关的 MDA-MB231A 人乳腺癌细胞没有特异性。结果讨论了 EP54/EP67 选择性靶向抗原并激活 C5a 受体携带抗原呈递细胞的能力，以及使用此类疫苗治疗淋巴瘤和其他癌症的前景。
