Porcine circovirus type 3 (PCV3) infection induces porcine dermatitis and nephropathy syndrome, reproductive failure, and multisystemic inflammatory lesions in piglets and sows. To better understand the host responses to PCV3 infection, isobaric tags for relative and absolute quantification (iTRAQ) labeling combined with LC-MS/MS analysis was used for quantitative determination of differentially regulated cellular proteins in the lungs of specific-pathogen-free piglets after 4 weeks of PCV3 infection. Totally, 3429 proteins were detected in three independent mass spectrometry analyses, of which 242 differential cellular proteins were significantly regulated, consisting of 100 upregulated proteins and 142 downregulated proteins in PCV3-infected group relative to control group. Bioinformatics analysis revealed that these higher or lower abundant proteins involved primarily metabolic processes, innate immune response, MHC-I and MHC-II components, and phagosome pathways. Ten genes encoding differentially regulated proteins were selected for investigation via real-time RT-PCR. The expression levels of six representative proteins, OAS1, Mx1, ISG15, IFIT3, SOD2, and HSP60, were further confirmed by Western blotting and immunohistochemistry. This study attempted for the first time to investigate the protein profile of PCV3-infected piglets using iTRAQ technology; our findings provide valuable information to better understand the mechanisms underlying the host responses to PCV3 infection in piglets. SIGNIFICANCE: Our study identified differentially abundant proteins related to a variety of potential signaling pathways in the lungs of PCV3-infected piglets. These findings provide valuable information to better understand the mechanisms of host responses to PCV3 infection.

中文翻译：

---

基于ITRAQ的定量蛋白质组学揭示了感染猪圆环病毒3型的仔猪的第一个蛋白质组谱。

猪圆环病毒3型（PCV3）感染在猪和母猪中诱发猪皮炎和肾病综合征，生殖衰竭以及多系统性炎症。为了更好地了解宿主对PCV3感染的反应，将同相和绝对定量（iTRAQ）标记的同量异位标签与LC-MS / MS分析相结合，用于定量确定无特定病原体仔猪肺中差异调节的细胞蛋白。 PCV3感染4周。在三个独立的质谱分析中，总共检测到3429种蛋白质，其中PCV3感染组相对于对照组显着调节了242种差异细胞蛋白质，其中包括100种上调的蛋白质和142种下调的蛋白质。生物信息学分析表明，这些丰度较高或较低的蛋白质主要涉及代谢过程，先天免疫应答，MHC-I和MHC-II成分以及吞噬途径。通过实时RT-PCR选择了10个编码差异调节蛋白的基因进行研究。Western blotting和免疫组织化学进一步证实了OAS1，Mx1，ISG15，IFIT3，SOD2和HSP60这六种代表性蛋白的表达水平。这项研究首次尝试使用iTRAQ技术研究感染PCV3的仔猪的蛋白质谱。我们的发现提供了有价值的信息，可以更好地了解宿主对仔猪PCV3感染的宿主应答机制。意义：我们的研究确定了感染PCV3的仔猪肺中与多种潜在信号通路相关的差异丰富的蛋白质。这些发现提供了宝贵的信息，可以更好地理解宿主对PCV3感染的反应机制。