Luff Jennifer A, Yuan Hang, Suter Maja M, Müller Eliane J, Schlegel Richard, Moore Peter F
Department of Veterinary Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
Vet Immunol Immunopathol. 2013 Jun 15;153(3-4):177-86. doi: 10.1016/j.vetimm.2013.02.001. Epub 2013 Mar 5.
Papillomaviruses (PV) are double stranded (ds) DNA viruses that infect epithelial cells within the skin or mucosa, most often causing benign neoplasms that spontaneously regress. The immune system plays a key role in the defense against PVs. Since these viruses infect keratinocytes, we wanted to investigate the role of the keratinocyte in initiating an immune response to canine papillomavirus-2 (CPV-2) in the dog. Keratinocytes express a variety of pattern recognition receptors (PRR) to distinguish different cutaneous pathogens and initiate an immune response. We examined the mRNA expression patterns for several recently described cytosolic nucleic acid sensing PRRs in canine monolayer keratinocyte cultures using quantitative reverse transcription-polymerase chain reaction. Unstimulated normal cells were found to express mRNA for melanoma differentiation associated gene 5 (MDA5), retinoic acid-inducible gene I (RIG-I), DNA-dependent activation of interferon regulatory factors, leucine rich repeat flightless interacting protein 1, and interferon inducible gene 16 (IFI16), as well as their adaptor molecules myeloid differentiation primary response gene 88, interferon-β promoter stimulator 1, and endoplasmic reticulum-resident transmembrane protein stimulator of interferon genes. When stimulated with synthetic dsDNA [poly(dA:dT)] or dsRNA [poly(I:C)], keratinocytes responded with increased mRNA expression levels for interleukin-6, tumor necrosis factor-α, interferon-β, RIG-I, IFI16, and MDA5. There was no detectable increase in mRNA expression, however, in keratinocytes infected with CPV-2. Furthermore, CPV-2-infected keratinocytes stimulated with poly(dA:dT) and poly(I:C) showed similar mRNA expression levels for these gene products when compared with expression levels in uninfected cells. These results suggest that although canine keratinocytes contain functional PRRs that can recognize and respond to dsDNA and dsRNA ligands, they do not appear to recognize or initiate a similar response to CPV-2.
乳头瘤病毒（PV）是双链（ds）DNA病毒，可感染皮肤或黏膜内的上皮细胞，最常见的是引起可自发消退的良性肿瘤。免疫系统在抵御PV中起关键作用。由于这些病毒感染角质形成细胞，我们想研究角质形成细胞在引发犬对犬乳头瘤病毒2型（CPV-2）的免疫反应中的作用。角质形成细胞表达多种模式识别受体（PRR）以区分不同的皮肤病原体并引发免疫反应。我们使用定量逆转录-聚合酶链反应检测了犬单层角质形成细胞培养物中几种最近描述的胞质核酸传感PRR的mRNA表达模式。发现未受刺激的正常细胞表达黑色素瘤分化相关基因5（MDA5）、视黄酸诱导基因I（RIG-I）、干扰素调节因子的DNA依赖性激活、富含亮氨酸重复序列的无翅相互作用蛋白1和干扰素诱导基因16（IFI16）的mRNA，以及它们的衔接分子髓样分化初级反应基因88、干扰素-β启动子刺激物1和内质网驻留跨膜蛋白干扰素基因刺激物。当用合成双链DNA[聚（dA:dT）]或双链RNA[聚（I:C）]刺激时，角质形成细胞中白细胞介素-6、肿瘤坏死因子-α、干扰素-β、RIG-I、IFI16和MDA5的mRNA表达水平升高。然而，感染CPV-2的角质形成细胞中mRNA表达没有可检测到的增加。此外，与未感染细胞中的表达水平相比，用聚（dA:dT）和聚（I:C）刺激的CPV-2感染的角质形成细胞对这些基因产物的mRNA表达水平相似。这些结果表明，尽管犬角质形成细胞含有可识别并响应双链DNA和双链RNA配体的功能性PRR，但它们似乎不能识别CPV-2或对其引发类似反应。
