Prudencio Carlos Roberto, Rodrigues Aline Aparecida Rezende, Cardoso Rone, Szabó Matias Pablo Juan, Goulart Luiz Ricardo
Laboratório de Nanobiotecnologia, Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil.
J Biomol Screen. 2011 Oct;16(9):1027-36. doi: 10.1177/1087057111414901. Epub 2011 Aug 15.
Identification of tick-protective antigens remains the limiting step in vaccine development. The authors have generated several B cell epitope candidates by fingerprinting Rhipicephalus (Boophilus) microplus proteins that were characterized through bioselection of random peptide phage display libraries against polyclonal antibodies antitick proteins. From 280 clones selected and sequenced, 107 distinct reactive clones were validated by dot-blot assays. Eight consensus motifs were generated, and the most frequent ones were PXXKXH, NXXKXXL, and HTS (68.2%, 65%, and 42%, respectively). The consensus sequences identified potential vaccine targets by alignment with the protein database of R. microplus, which may have putative roles in the host response. Sequences that did not align with known proteins but shared extensive homology among each other were classified as conformational epitopes. Sequence alignments also recognized multiple targets, and the most predominant proteins were identified. Finally, immunized mice sera recognized tick proteins, demonstrating that functional epitope profiles can be identified through selection of phage-displayed peptide libraries with hyperimmune sera and revealing that the epitope-displaying phages can be used as potential vaccine immunogens.
蜱保护性抗原的鉴定仍然是疫苗开发中的限制步骤。作者通过对微小扇头蜱（Boophilus microplus）蛋白质进行指纹识别，产生了几种B细胞表位候选物，这些候选物通过针对抗蜱蛋白多克隆抗体的随机肽噬菌体展示文库的生物筛选进行表征。从280个选择并测序的克隆中，通过斑点印迹分析验证了107个不同的反应性克隆。生成了八个共有基序，最常见的是PXXKXH、NXXKXXL和HTS（分别为68.2%、65%和42%）。通过与微小扇头蜱的蛋白质数据库比对，这些共有序列确定了潜在的疫苗靶点，这些靶点可能在宿主反应中具有假定作用。与已知蛋白质不比对但彼此之间具有广泛同源性的序列被分类为构象表位。序列比对还识别出多个靶点，并确定了最主要的蛋白质。最后，免疫小鼠血清识别蜱蛋白，表明通过用超免疫血清选择噬菌体展示肽文库可以鉴定功能性表位谱，并揭示展示表位的噬菌体可作为潜在的疫苗免疫原。
