Haig D, McInnes C, Deane D, Lear A, Myatt N, Reid H, Rothel J, Seow H F, Wood P, Lyttle D, Mercer A
Moredun Research Institute, Edinburgh, UK.
Vet Immunol Immunopathol. 1996 Nov;54(1-4):261-7. doi: 10.1016/s0165-2427(96)05687-5.
The epitheliotropic parapoxvirus, orf virus, can repeatedly infect sheep skin. A specific immune response is generated as reinfections induce smaller lesions with quicker resolution times than primary lesions. Cyclosporin-A treatment abrogates this partial immunity. Cytokine mRNAs detected in lesion biopsies include the transcripts for IL-1 beta, IL-3 GM-CSF, TNF-alpha and, less reproducibly, IFN-gamma. CD4+ T-cells predominate in afferent lymph draining the site of infection, and are the major source of GM-CSF and IFN-gamma. IL-1 beta and IL-8 are also detected. The orf virus genome contains a homologue of mammalian vascular endothelial growth factor that may enhance virulence and a vaccinia virus E3L-like gene which may inhibit the anti-viral effect of the interferons. A GM-CSF inhibitory activity has also been discovered and has been 'chased' into a 10 kb DNA segment of the orf virus genome. These studies indicate that orf virus may temporarily avoid host immunity by a combination of acute, rapid infection and replication in the epidermis and by producing virulence factors that inhibit protective proteins of the host immune and inflammatory response.
亲上皮性副痘病毒，即羊口疮病毒，可反复感染绵羊皮肤。再次感染时会产生特异性免疫反应，与原发性损伤相比，再次感染引起的损伤更小，愈合时间更快。环孢素A治疗可消除这种部分免疫。在损伤活检中检测到的细胞因子mRNA包括白细胞介素-1β、白细胞介素-3、粒细胞-巨噬细胞集落刺激因子、肿瘤坏死因子-α的转录本，以及重现性较差的干扰素-γ的转录本。在引流感染部位的输入淋巴中，CD4 + T细胞占主导地位，并且是粒细胞-巨噬细胞集落刺激因子和干扰素-γ的主要来源。还检测到白细胞介素-1β和白细胞介素-8。羊口疮病毒基因组包含一个可能增强毒力的哺乳动物血管内皮生长因子的同源物和一个可能抑制干扰素抗病毒作用的痘苗病毒E3L样基因。还发现了一种粒细胞-巨噬细胞集落刺激因子抑制活性，并已追踪到羊口疮病毒基因组的一个10 kb DNA片段中。这些研究表明，羊口疮病毒可能通过在表皮中急性、快速感染和复制以及产生抑制宿主免疫和炎症反应保护蛋白的毒力因子的组合来暂时逃避宿主免疫。
