Oliveira Eliandre de, Jiménez-Clavero Miguel Angel, Núñez José Ignacio, Sobrino Francisco, Andreu David
Department of Experimental and Health Sciences, Pompeu Fabra University, Dr. Aiguader 80, 08003 Barcelona, Spain.
Vaccine. 2005 Apr 8;23(20):2647-57. doi: 10.1016/j.vaccine.2004.10.041.
The design of vaccines for RNA viral diseases is complicated by the high genetic variability of the viruses, which favors the selection of escape mutants. A case in point is foot-and-mouth disease virus (FMDV), for which only limited protection has been observed in vaccination with single peptides. We have explored the potential of immunogens of higher sequence diversity, covering a broad range of field or culture-induced mutations at the immunodominant site A of FMDV, serotype C. Four mixotope-type peptide libraries, containing ca. 3 x 10(3) or ca. 3 x 10(5) peptides each, in either linear or cyclic form, and combining most significant mutations found or induced at site A have been synthesized and used to immunize guinea-pigs. Substantial levels of serum conversion have been observed for all four mixotope libraries, as well as for single peptides, linear or cyclic, corresponding to the consensus site A sequence. The specificity and neutralizing ability of the anti-mixotope and -peptide antibodies have been evaluated by direct ELISA and by plaque reduction and micro-neutralization assays, respectively. Challenge experiments with an infectious, guinea-pig-adapted FMDV strain, have shown higher protection rates in animals immunized with the cyclic versions, either in single sequence or in combinatorial mixotope form.
RNA病毒疾病疫苗的设计因病毒的高遗传变异性而变得复杂，这种高遗传变异性有利于逃逸突变体的选择。一个典型的例子是口蹄疫病毒（FMDV），在用单肽进行疫苗接种时，仅观察到有限的保护作用。我们探索了具有更高序列多样性的免疫原的潜力，这些免疫原涵盖了FMDV C型免疫显性位点A处广泛的田间或培养诱导突变。已经合成了四个混合同位素型肽库，每个库包含约3×10³或约3×10⁵个线性或环状形式的肽，并结合了在A位点发现或诱导的最显著突变，用于免疫豚鼠。对于所有四个混合同位素库以及与共有位点A序列相对应的线性或环状单肽，均观察到了相当水平的血清转化。分别通过直接ELISA以及蚀斑减少和微量中和试验评估了抗混合同位素和抗肽抗体的特异性和中和能力。用感染性、豚鼠适应的FMDV毒株进行的攻毒实验表明，用环状形式（单序列或组合混合同位素形式）免疫的动物具有更高的保护率。
