Chen Lan, Deng Li-Shuang, Xu Tong, Lai Si-Yuan, Ai Yan-Ru, Zhu Ling, Xu Zhi-Wen
College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.
Sichuan Key Laboratory of Animal Epidemic Disease and Human Health, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.
Front Microbiol. 2024 Jul 29;15:1443119. doi: 10.3389/fmicb.2024.1443119. eCollection 2024.
Porcine circovirus 4 (PCV4) was first identified in 2019, categorized within the genus in the family . To date, the virus has not been isolated from clinical samples. Meanwhile, many aspects of the biology and pathogenic mechanisms of PCV4 infection remain unknown. In this study, PCV4 was successfully rescued from an infectious clone. We utilized a PCV4 virus stock derived from this infectious clone to intranasally inoculate 4-week-old specific-pathogen-free piglets to evaluate PCV4 pathogenesis. The rescued PCV4 was capable of replicating in both PK-15 cells and piglets, with the virus detectable in nearly all collected samples from the challenge groups. Pathological lesions and PCV4-specific antigens were observed in various tissues and organs, including the lungs, kidneys, lymph nodes, spleen, and liver, in the inoculated piglets. Additionally, the levels of pro-inflammatory cytokines in the serum of the PCV4-inoculated group were significantly elevated compared to the control group, indicating that the induced inflammatory response may contribute to tissue damage associated with PCV4 infection. These findings offer new insights into the pathogenesis and inflammatory responses associated with PCV4-related diseases.
猪圆环病毒4型（PCV4）于2019年首次被鉴定出来，归类于圆环病毒科圆环病毒属。迄今为止，尚未从临床样本中分离出该病毒。与此同时，PCV4感染的生物学和致病机制的许多方面仍然未知。在本研究中，通过感染性克隆成功拯救出PCV4。我们利用源自该感染性克隆的PCV4病毒株对4周龄的无特定病原体仔猪进行鼻内接种，以评估PCV4的致病性。拯救出的PCV4能够在PK-15细胞和仔猪中复制，在攻毒组几乎所有采集的样本中都能检测到该病毒。在接种的仔猪的各种组织和器官中，包括肺、肾、淋巴结、脾脏和肝脏，观察到了病理损伤和PCV4特异性抗原。此外，与对照组相比，PCV4接种组血清中的促炎细胞因子水平显著升高，表明诱导的炎症反应可能导致与PCV4感染相关的组织损伤。这些发现为与PCV4相关疾病的发病机制和炎症反应提供了新的见解。
