Khatri Mahesh, Sharma Jagdev M
Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108, USA.
Vet Immunol Immunopathol. 2007 May 15;117(1-2):106-15. doi: 10.1016/j.vetimm.2007.02.002. Epub 2007 Feb 16.
We serially passaged classical infectious bursal disease virus (cIBDV) and antigenic variant IBDV (vIBDV) in an avian macrophage cell line, NCSU cells, referred as mcIBDV and mvIBDV respectively and examined the in vitro and in vivo characteristics of the macrophage-adapted viruses. NCSU adapted viruses caused earlier destruction of NCSU cells than the unadapted viruses. Nitric oxide (NO) was detected earlier in cultures infected with mcIBDV and mvIBDV than in cultures infected with cIBDV and vIBDV. cIBDV and vIBDV were able to infect DF-1 cells, a chicken embryo fibroblast cell line, only after one replication cycle in NCSU cells. The genetic basis of altered tropism of progeny virus from NCSU cells infected cultures was not identified. No aa substitutions were observed in hypervariable region of VP2 of cIBDV and vIBDV passaged 1 time in NCSU cells whereas both mcIBDV and mvIBDV had multiple aa substitutions. To assess protective efficacy of mcIBDV and mvIBDV, embryonated chicken eggs were inoculated with mcIBDV and mvIBDV at embryonation day 18 (ED 18) and challenged with a virulent cIBDV at 3 weeks of age. mcIBDV and mvIBDV were immunogenic and generated antibody responses and provided 100% protection against cIBDV.
我们在一种禽类巨噬细胞系NCSU细胞中对经典传染性法氏囊病病毒（cIBDV）和抗原变异型传染性法氏囊病病毒（vIBDV）进行连续传代，分别称为mcIBDV和mvIBDV，并检测了巨噬细胞适应性病毒的体外和体内特性。与未适应的病毒相比，NCSU适应病毒导致NCSU细胞更早地被破坏。在感染mcIBDV和mvIBDV的培养物中，一氧化氮（NO）的检测时间早于感染cIBDV和vIBDV的培养物。cIBDV和vIBDV仅在NCSU细胞中经过一个复制周期后才能感染鸡胚成纤维细胞系DF-1细胞。未确定感染NCSU细胞的培养物中后代病毒嗜性改变的遗传基础。在NCSU细胞中传代1次的cIBDV和vIBDV的VP2高变区未观察到氨基酸替代，而mcIBDV和mvIBDV均有多个氨基酸替代。为了评估mcIBDV和mvIBDV的保护效力，在胚胎发育第18天（ED 18）用mcIBDV和mvIBDV接种鸡胚，并在3周龄时用强毒cIBDV进行攻毒。mcIBDV和mvIBDV具有免疫原性，能产生抗体反应，并提供100%针对cIBDV的保护。
