Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, AP 70228, Cuidad Universitaria, México, Distrito Federal 04510, Mexico.
Vaccine. 2011 Jul 18;29(32):5313-21. doi: 10.1016/j.vaccine.2011.05.007. Epub 2011 May 19.
The extreme antigenic variability of human immunodeficiency virus (HIV) leads to immune escape of the virus, representing a major challenge in the design of effective vaccine. We have developed a novel concept for immunogen construction based on introduction of massive mutations within the epitopes targeting antigenically variable pathogens and diseases. Previously, we showed that these immunogens carrying large combinatorial libraries of mutated epitope variants, termed as variable epitope libraries (VELs), induce potent, broad and long lasting CD8+IFN-γ+ T-cell response. Moreover, we demonstrated that these T cells recognize more than 50% of heavily mutated variants (5 out of 10 amino acid positions were mutated in each epitope variant) of HIV-1 gp120 V3 loop-derived cytotoxic T lymphocyte epitope (RGPGRAFVTI) in mice. The constructed VELs had complexities of 10000 and 12500 individual members, generated as plasmid DNA or as M13 phage display combinatorial libraries, respectively, and with structural composition RGPGXAXXXX or XGXGXAXVXI, where X is any of 20 natural amino acids. Here, we demonstrated that sera from mice immunized with these VELs are capable of neutralizing 5 out of 10 viral isolates from Tier 2 reference panel of subtype B envelope clones, including HIV-1 isolates which are known to be resistant to neutralization by several potent monoclonal antibodies, described previously. These data indicate the feasibility of the application of immunogens based on VEL concept as an alternative approach for the development of molecular vaccines against antigenically variable pathogens.
人类免疫缺陷病毒（HIV）的极端抗原变异性导致病毒的免疫逃逸，这是设计有效疫苗的主要挑战。我们基于在针对抗原可变病原体和疾病的表位中引入大量突变的概念，开发了一种新型免疫原构建方法。以前，我们表明，这些携带大量突变表位变体组合文库的免疫原，称为可变表位文库（VEL），可诱导强烈、广泛和持久的 CD8+IFN-γ+T 细胞反应。此外，我们证明这些 T 细胞能够识别超过 50%的 HIV-1 gp120 V3 环衍生的细胞毒性 T 淋巴细胞表位（RGPGRAFVTI）的高度突变变体（每个表位变体中有 5 个氨基酸位置发生突变）在小鼠中。构建的 VEL 复杂度分别为 10000 和 12500 个成员，分别作为质粒 DNA 或 M13 噬菌体展示组合文库产生，结构组成分别为 RGPGXAXXXX 或 XGXGXAXVXI，其中 X 是 20 种天然氨基酸中的任意一种。在这里，我们证明用这些 VEL 免疫的小鼠的血清能够中和来自 B 亚型包膜克隆二级参考面板的 10 个病毒分离物中的 5 个，包括已知对几种先前描述的强效单克隆抗体具有抗性的 HIV-1 分离物。这些数据表明，基于 VEL 概念的免疫原作为针对抗原可变病原体的分子疫苗开发的替代方法具有可行性。
