猪细小病毒生物学研究

题目：猪细小病毒生物学研究

Porcine parvovirus (PPV) is among the most important infectious agents causing infertility in pigs. Until recently, it was thought that the virus had low genetic variance, and that prevention of its harmful effect on pig fertility could be well-controlled by vaccination. However, at the beginning of the third millennium, field observations raised concerns about the effectiveness of the available vaccines against newly emerging strains. Subsequent investigations radically changed our view on the evolution and immunology of PPV, revealing that the virus is much more diverse than it was earlier anticipated, and that some of the “new” highly virulent isolates cannot be neutralized effectively by antisera raised against “old” PPV vaccine strains. These findings revitalized PPV research that led to significant advancements in the understanding of early and late viral processes during PPV infection. Our review summarizes the recent results of PPV research and aims to give a comprehensive update on the present understanding of PPV biology.

摘要：猪细小病毒(PPV)是引起猪繁殖问题的最重要传染因子之一。直到最近，人们还认为该病毒的遗传变异很小，可以通过接种疫苗很好地控制其对猪繁殖能力的影响。然而，实地观察引起了人们对现有疫苗对新出现毒株效力的关注。随后的调查从根本上改变了我们对PPV进化和免疫学的看法，揭示了该病毒比早期预期的更加多样化，并且一些“新的”高毒力分离株不能针对“旧的”PPV疫苗株的抗血清有效中和。这些发现重振了PPV的研究，导致对PPV感染早期和晚期病毒过程的理解取得了重大进展。本文综述了近年来PPV的研究成果，旨在对PPV生物学的认识进行全面的更新。

图1：猪细小病毒(PPV)感染的主要时间点及免疫应答。母源抗体被动保护仔猪(绿线)直到9-22周龄。在母源抗体耗尽后，先对动物进行接种，通过加强接种来保持长期免疫力。在妊娠第70天左右免疫力发育(绿线)之前，胚胎易受感染(红线)。宫内感染的后果取决于感染的时间。

注释：Gestation：妊娠

Passive immunity：被动免疫

Seronegativity：血清阴性

Initial vaccination：初始免疫

Booster vaccination：加强免疫

Conception：妊娠

Hatching：孵化

Placentation：胎盘形成

Ossification：成骨

Susceptible to PPV：PPV易感

Embryonic death and resorption：胚胎死亡和吸收

Fetal death and mummification：死胎和木乃伊化

Immunologic competency：免疫能力

Survival and seropositivity：存活和血清阳性

图2：PPV衣壳蛋白2(VP2)三聚体表面具有已知功能的氨基酸残基