GENETIC STUDIES OF ROTAVIRUS PATHOGENESIS AND DEVELOPMENT OF ROTAVIRUS VACCINES

此前，在涉及半同源基因的研究中 共生新生猪和强毒猪轮状病毒系统 强毒株(SB-1A)和人轮状病毒弱毒株(DS-1)以及 他们的重排，我们证明了：(I)第三(VP3)，第四 猪轮状病毒基因(VP4)、第九基因(VP7)或第十基因(NSP4) 在轮状病毒毒力中发挥重要的独立作用 仔猪感染；及(Ii)所有四种猪轮状病毒 毒力相关基因是引起腹泻所必需的 以及仔猪排出轮状病毒。这些观察结果 提出了一种潜在的削弱野生型病毒的新策略 具有重要流行病学意义的人类轮状病毒及其研究进展 应用于开发安全有效的疫苗。 使用这个策略，我们成功地产生了四个双打 基因替代人x牛轮状病毒重组体，每个 它处理了以下内容：(I)来自 人轮状病毒Wa(VP4：1A)；(Ii)编码VP7的基因 人轮状病毒D(VP7：1)、DS-1(VP7：2)、P(VP7：3)或ST3 (VP7：4)；及。(Iii)其余九个基因，包括 牛VP3编码基因和NSP4编码基因 轮状病毒英国。此外，我们还成功地生成了两个人类x 牛和两个人x恒河猴轮状病毒单基因替换 重组体，每个重组体都有来自 人轮状病毒Wa(VP4：1A)或DS-1(VP4：1B)和 来自牛轮状病毒UK或恒河猴的剩余基因 轮状病毒MMU18006。最近，罕见的VP7(G)血清型 导致人类感染的高发病例已在 世界各地，包括巴西的G5菌株和G9 以及印度的G10菌株。因为在未来有可能 这种G血清型可能需要包括在我们的疫苗中 因此，为了做好准备，我们生成了三个 恒河猴x人和三个牛x人轮状病毒重组体， 每一个都只有一个来自人类轮状病毒的基因编码 G5、G9或G10特异性，以及来自任何一种的剩余基因 恒河猴轮状病毒MMU18006或牛轮状病毒UK。这样的菌株 可能会被证明对发展一个最优的 有效的轮状病毒疫苗。

Previously, in studies involving a semi-homologous system of gnotobiotic newborn pigs and a virulent porcine rotavirus strain (SB-1A) and an avirulent human rotavirus strain (DS-1) and their reassortants, we demonstrated that: (i) the third (VP3), fourth (VP4), ninth (VP7), or tenth (NSP4) porcine rotavirus gene each play an important independent role in the virulence of rotavirus infection in piglets; and (ii) all four of the porcine rotavirus virulence-associated genes are required for the induction of diarrhea and the shedding of rotavirus by piglets. These observations suggested a potential new strategy for attenuation of wild-type human rotaviruses of major epidemiological importance and its application to the development of a safe and effective vaccine. Using this strategy, we were successful in generating four double gene substitution human x bovine rotavirus reassortants, each of which processed the following: (i) the VP4-encoding gene from human rotavirus Wa (VP4:1A); (ii) the VP7-encoding gene from human rotavirus D (VP7:1), DS-1 (VP7:2), P (VP7:3) or ST3 (VP7:4); and (iii) the remaining nine genes including the VP3-encoding gene and NSP4-encoding gene from bovine rotavirus UK. In addition, we successfully generated two human x bovine and two human x rhesus rotavirus single gene substitution reassortants, each of which had the VP4- encoding gene from human rotavirus Wa (VP4:1A) or DS-1 (VP4:1B) and the remaining genes from either bovine rotavirus UK or rhesus rotavirus MMU18006. Recently, unusual VP7 (G) serotypes causing a high incidence of human infection have been detected in various parts of the world including G5 strains in Brazil, and G9 and G10 strains in India. Because of the possibility in the future that such G serotypes might need to be included in our vaccine candidates and therefore to ?be prepared?, we generated three rhesus x human and three bovine x human rotavirus reassortants, each of which had only one gene from human rotavirus encoding G5, G9, or G10 specificity, and the remaining genes from either rhesus rotavirus MMU18006 or bovine rotavirus UK. Such strains may prove to be important for the development of an optimally effective rotavirus vaccine.