Generation of a candidate live marker vaccine for equine arteritis virus by deletion of the major virus neutralization domain
Generation of a candidate live marker vaccine for equine arteritis virus by deletion of the major virus neutralization domain
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DOI：
10.1128/jvi.77.15.8470-8480.2003
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发表时间：
2003-08-01
影响因子：
5.4
通讯作者：
Rottier, PJM
中科院分区：
文献类型：
--
作者：
Castillo-Olivares, J;Wieringa, R;Rottier, PJM
马动脉炎病毒(Eav)是一种囊膜正链RNA病毒，属于新城疫病毒目(Arteriviridae)，可引起马类的呼吸道和生殖疾病。由感染引起的保护性病毒中和抗体(VNAb)主要针对病毒包膜糖蛋白G(L)膜近端区域的免疫优势区域，从而使最近建立了基于该特定区域的敏感多肽酶联免疫吸附试验(J.Nugent等人，J.Virol)。方法90：167-183,2000)。通过使用有感染性的cDNA，我们现在已经在无毒病毒的受控背景下产生了一个突变的EAV，这个免疫优势结构域从中被删除了。这种名为EAV-G(L)Delta的病毒在培养细胞中复制到正常滴度，尽管复制速度比野生型EAV慢，并导致了小马的无症状感染。所诱导的抗体在体外能有效地中和突变病毒，但对野生型EaV株反应较差。然而，当随后接种强毒Eav时，与未接种疫苗的对照组相比，免疫的动物对疾病完全保护；挑战病毒的复制短暂地发生在低水平但可检测到的水平。达到的保护水平表明，VNAb以外的免疫效应机制在预防感染方面发挥着重要作用。正如预期的那样，感染EAV-G(L)Delta在我们的G(L)-肽酶联免疫吸附试验中没有引起可测量的反应，而动物的攻击感染明显引起了可测量的反应。因此，EAV-G(L)Delta或类似的突变体是有吸引力的标记疫苗候选，使接种和野生型病毒感染的动物能够在血清学上区分开来。
Equine arteritis virus (EAV) is an enveloped plus-strand RNA virus of the family Arteriviridae (order Nidovirales) that causes respiratory and reproductive -disease in equids. Protective, virus-neutralizing antibodies (VNAb) elicited by infection are directed predominantly against an immunodominant region in the membraneproximal domain of the viral envelope glycoprotein G(L), allowing recently the establishment of a sensitive peptide enzyme-linked immunosorbent assay (ELISA) based on this particular domain (J. Nugent et al., J. Virol. Methods 90:167-183, 2000). By using an infectious cDNA we have now generated, in the controlled background of a nonvirulent virus, a mutant EAV from which this immunodominant domain was deleted. This virus, EAV-G(L)Delta, replicated to normal titers in culture cells, although at a slower rate than wild-type EAV, and caused an asymptomatic infection in ponies. The antibodies induced neutralized the mutant virus efficiently in vitro but reacted poorly to wild-type EAV strains. Nevertheless, when inoculated subsequently with virulent EAV, the immunized animals, in contrast to nonvaccinated controls, were fully protected against disease; replication of the challenge virus occurred briefly at low though detectable levels. The levels of protection achieved suggest that an immune effector mechanism other than VNAb plays an important role in protection against infection. As expected, infection with EAV-G(L)Delta did not induce a measurable response in our G(L)-peptide ELISA while the challenge infection of the animals clearly did. EAV-G(L)Delta or similar mutants are therefore attractive marker vaccine candidates, enabling serological discrimination between vaccinated and wild-type virus-infected animals.