Meloen R H, Turkstra J A, Lankhof H, Puijk W C, Schaaper W M, Dijkstra G, Wensing C J, Oonk R B
Central Veterinary Institute (CDI-DLO), Lelystad, The Netherlands.
Vaccine. 1994 Jun;12(8):741-6. doi: 10.1016/0264-410x(94)90226-7.
Active immunization to immunomodulate regulatory processes suffers from the disadvantage that the antigen is usually 'self' and therefore poorly immunogenic. This has been well illustrated by the long-standing experience with immunocastration vaccines targeting GnRH, a ten amino acid peptide. Not all animals vaccinated with these vaccines are equally affected, even after multiple vaccinations. This is a severe handicap when immunocastration vaccines are applied to male piglets to circumvent surgical castration. Surgical castration is universally practised to prevent boar taint, produced in the testicles of mature boars. Alternative immunocastration is only acceptable if all animals are equally affected using a minimum of vaccinations. Vaccines based on the GnRH peptide itself cannot meet these goals. We showed that using a GnRH-like peptide, a 20 amino acid tandem repeat of the amino acid sequence of the GnRH peptide, these goals can be attained. Using the tandem GnRH peptide to vaccinate male piglets completely abolished the development and endocrinological functioning of the testicles, in contrast to monomer GnRH. These results show that superior antigens can be made for effective immunomodulation by appropriate alteration of the antigen.
通过主动免疫来调节免疫过程存在一个缺点，即抗原通常是“自身”的，因此免疫原性较差。针对促性腺激素释放激素（GnRH，一种十肽）的免疫去势疫苗的长期经验很好地说明了这一点。即使多次接种疫苗，并非所有接种这些疫苗的动物都会受到同等程度的影响。当将免疫去势疫苗应用于雄性仔猪以避免手术去势时，这是一个严重的障碍。手术去势普遍用于防止成熟公猪睾丸产生的公猪异味。只有在使用最少的疫苗接种就能使所有动物受到同等影响的情况下，替代免疫去势才是可接受的。基于GnRH肽本身的疫苗无法实现这些目标。我们表明，使用一种GnRH样肽，即GnRH肽氨基酸序列的20个氨基酸串联重复序列，可以实现这些目标。与单体GnRH相比，使用串联GnRH肽对雄性仔猪进行疫苗接种完全消除了睾丸的发育和内分泌功能。这些结果表明，通过对抗原进行适当改变，可以制备出用于有效免疫调节的优质抗原。
