Shahsavandi Shahla, Ebrahimi Mohammad Majid, Sadeghi Kaveh, Mahravani Homayoon
Razi Vaccine and Serum Research Institute, PO box 31975-148, Karaj, Iran,
In Vitro Cell Dev Biol Anim. 2014 Oct;50(9):858-64. doi: 10.1007/s11626-014-9783-9. Epub 2014 Jul 4.
Infectious bursal disease virus (IBDV) induces immunodeficiency in young chickens and apoptosis in chicken embryos. To understand the relation between the viral pathogenesis and the induction of cell death, chicken embryonic fibroblast (CEF) cells were infected with IBDV intermediate (im) and very virulent (vv) strains at different MOIs. The cell viability and DNA fragmentation were evaluated in infected cells. The cellular apoptotic pathway involve was investigated by determining the activities of caspase cascade. The imIBDV strain was replicated well in CEF cells and shown higher viral titers than vvIBDV. Apoptosis changes were observed only in vvIBDV-infected CEF cells at higher MOI 48 h post infection. Efflux of cytochrome c suggests that the intrinsic pathway of the apoptotic process induced by vvIBDV infection independently of virus replication. Prediction of caspase substrates cleavage sites revealed that different IBDV strains have conserved cleavage motif pattern for VP2 and VP5 viral proteins. These findings suggest the pathogenicity of IBDV strains might be involved in the induction of apoptosis in host cells.
传染性法氏囊病病毒（IBDV）可导致幼鸡免疫缺陷，并在鸡胚中诱导细胞凋亡。为了解病毒致病机制与细胞死亡诱导之间的关系，用不同感染复数（MOI）的IBDV中等毒力（im）株和超强毒力（vv）株感染鸡胚成纤维细胞（CEF）。对感染细胞的细胞活力和DNA片段化进行评估。通过测定半胱天冬酶级联反应的活性来研究细胞凋亡途径。imIBDV株在CEF细胞中复制良好，且病毒滴度高于vvIBDV。感染48小时后，仅在MOI较高的vvIBDV感染的CEF细胞中观察到凋亡变化。细胞色素c的外流表明，vvIBDV感染诱导的凋亡过程的内在途径独立于病毒复制。对半胱天冬酶底物切割位点的预测表明，不同的IBDV株对VP2和VP5病毒蛋白具有保守的切割基序模式。这些发现表明，IBDV株的致病性可能与宿主细胞凋亡的诱导有关。
