PLoS One. 2013 Jun 25;8(6):e67137. doi: 10.1371/journal.pone.0067137. Print 2013.
West Nile Virus (WNV) arrived in North America in 1999 and is now endemic. Many families of birds, especially corvids, are highly susceptible to WNV and infection often results in fatality. Avian species susceptible to WNV infection also include endangered species, such as the Greater Sage-Grouse (Centrocercus uropbasianuts) and the Eastern Loggerhead Shrike (Lanius ludovicianus migrans). The virus has been shown to contribute towards the likelihood of their extinction. Although a clear and present threat, there exists no avian WNV vaccine available to combat this lethal menace. As a first step in establishing an avian model for testing candidate WNV vaccines, avian antibody based reagents were assessed for cross-reactivity with Japanese quail (Coturnix japonica) T cell markers CD4 and CD8; the most reactive were found to be the anti-duck CD8 antibody, clone Du-CD8-1, and the anti-chicken/turkey CD4 antibody, clone CT4. These reagents were then used to assess vaccine performance as well as to establish T cell populations in quail, with a novel population of CD4/CD8 double positive T cells being identified in Japanese quail. Concurrently, non-replicating recombinant adenoviruses, expressing either the WNV envelope or NS3 'genes' were constructed and assessed for effectiveness as avian vaccines. Japanese Quail were selected for testing the vaccines, as they provide an avian model that parallels the population diversity of bird species in the wild. Both the level of WNV specific antibodies and the number of T cells in vaccinated birds were increased compared to unvaccinated controls. The results indicate the vaccines to be effective in increasing both humoral and cellular immune responses. These recombinant vaccines therefore may find utility as tools to protect and maintain domestic and wild avian populations. Their implementation may also arrest the progression towards extinction of endangered avian species and reduce the viral reservoir that potentiates infection in humans.
西尼罗河病毒（WNV）于 1999 年抵达北美，现已成为地方病。许多鸟类家族，尤其是鸦科鸟类，对 WNV 高度易感，感染通常导致死亡。易感染 WNV 的鸟类物种还包括濒危物种，如大角羊（Centrocercus uropbasianuts）和东部 Loggerhead 画眉（Lanius ludovicianus migrans）。该病毒已被证明增加了它们灭绝的可能性。尽管这是一个明显且现实的威胁，但目前还没有针对这种致命威胁的鸟类 WNV 疫苗。作为建立禽类 WNV 候选疫苗测试模型的第一步，评估了基于禽类抗体的试剂与日本鹌鹑（Coturnix japonica）T 细胞标记物 CD4 和 CD8 的交叉反应性；最具反应性的是抗鸭 CD8 抗体克隆 Du-CD8-1 和抗鸡/火鸡 CD4 抗体克隆 CT4。然后，这些试剂被用于评估疫苗的性能，并在鹌鹑中建立 T 细胞群体，在日本鹌鹑中鉴定出一种新型的 CD4/CD8 双阳性 T 细胞群体。同时，构建并评估了表达 WNV 包膜或 NS3“基因”的非复制重组腺病毒作为禽类疫苗的有效性。选择日本鹌鹑进行疫苗测试，因为它们提供了一种与野生鸟类物种群体多样性相似的禽类模型。与未接种疫苗的对照组相比，接种疫苗的鸟类中的 WNV 特异性抗体水平和 T 细胞数量均增加。结果表明，这些疫苗可有效增强体液和细胞免疫反应。因此，这些重组疫苗可能可用作保护和维持家禽和野生禽类种群的工具。它们的实施也可能阻止濒危鸟类物种的灭绝进程，并减少感染人类的病毒库。
