Animal Health Biotechnology Group, Temasek Lifesciences Laboratory, The National University of Singapore, 1 Research Link, Singapore.
Virology. 2011 Feb 5;410(1):248-56. doi: 10.1016/j.virol.2010.11.009. Epub 2010 Dec 8.
The ORF3 protein of the pathogenic porcine circovirus 2 (PCV2) causes apoptosis of the virus-infected cells. In PCV2-infected piglets, ORF3 induces B and CD4 T lymphocyte depletion and lymphoid organ destruction and the ORF3-deficient PCV2 is attenuated in its pathogenicity (Virology, 383 (2009), 338). In addition to its role in causing the apoptosis of the immune cells, characteristic of the PCV2 infection associated disease conditions, the ORF3 also plays a role in the systemic dissemination of the PCV2 infection. Our experiments here show that ORF3 expedites the spread of the virus by inducing the early release of the virus from the infected cells. Further, in PCV2-infected mice, the ORF3-induced apoptosis also aids in recruiting macrophages to phagocytize the infected apoptotic cells leading to the systemic dissemination of the infection. The apoptotic activity of the ORF3 of PCV2 hence lends advantage to the spread of the virus.
致病性猪圆环病毒 2（PCV2）的 ORF3 蛋白导致病毒感染细胞凋亡。在 PCV2 感染的仔猪中，ORF3 诱导 B 和 CD4 T 淋巴细胞耗竭和淋巴器官破坏，并且 ORF3 缺失的 PCV2 在其致病性方面减弱（病毒学，383（2009），338）。除了在引起与 PCV2 感染相关的疾病状况的免疫细胞凋亡中发挥作用外，ORF3 还在 PCV2 感染的全身传播中发挥作用。我们在这里的实验表明，ORF3 通过诱导病毒从感染细胞中早期释放来加速病毒的传播。此外，在 PCV2 感染的小鼠中，ORF3 诱导的细胞凋亡还有助于招募巨噬细胞吞噬感染的凋亡细胞，从而导致感染的全身传播。因此，PCV2 的 ORF3 的凋亡活性有利于病毒的传播。
