Malaria Vaccines: Pfs28-rEPA/ALHYDROGEL

Pfs28已被证明可以诱导抗体，阻止蚊子体内寄生虫的发育。然而，这种蛋白的免疫原性很差。受增加Pfs25免疫原性的成功偶联策略的启发，我们也开发了Pfs28与rEPA偶联的工艺。评估了各种偶联化学和方法的最佳免疫原性和偶联过程的鲁棒性。研究了Pfs28-rEPA的生化特性，并对其偶联物进行了动物免疫原性评价。对结合疫苗诱导的免疫血清在蚊子体内阻断寄生虫发育的能力进行了测试。

Pfs28 has been shown to induce antibodies that can block parasite development in mosquitoes. However, the protein is poorly immunogenic. Inspired by success of the conjugation stratagy for increasing the immunogenicity of the Pfs25, we also developed a process to conjugate Pfs28 to rEPA. Various conjugation chemistries and methods were evaluated for the optimal immunogenicity and the robust conjugation processes. The biochemical properties of the Pfs28-rEPA were characterized and the conjugates were evaluated in animals for their immunogenicity. The immune sera induced by the conjugate vaccine were tested for their ability to block parasite development in mosquitoes. In parallel, we are also conjugating Pvs28, an ookinete surface protein in Plasmodium vivax parasite and encoded by an orthorlog gene of Pfs28, to rEPA. The Pvs28-rEPA will be combined with Pfs25-rEPA as a two-component vaccine to broaden the immune coverage and increase the vaccine efficacy.