Scott A N, Connor T J, Creelan J L, McNulty M S, Todd D
Department of Veterinary Science, Queen's University of Belfast, Belfast, U.K.
Arch Virol. 1999;144(10):1961-75. doi: 10.1007/s007050050718.
The Cux-1 isolate of chicken anaemia virus (CAV), which had received 310 (P310) cell culture passages, was substantially less pathogenic than virus that had been passaged 13 times (P13). Molecularly cloned virus isolates, selected from the P310 and P13 virus populations using recombinant DNA cloning and transfection procedures, reacted differently with 4 CAV-specific monoclonal antibodies (MAbs), which had been raised to low-passage Cux-1 virus. In contrast to the strong immunofluorescence (IF) reactivities exhibited by all P13 cloned isolates tested, 80% and 57% of the P310 cloned isolates reacted weakly with MAbs 2A9 and 4H4, which are directed against conformational epitopes on the capsid protein, VP1. Sequence analysis of the VP1 coding regions possessed by ten P310 and two P13 cloned isolates showed that 6 amino acid changes within VP1 had been selected by multiple-cell culture passage. One of these at position 89 in VP1 appeared to be crucial for determining reactivity with MAb 2A9. Of nine P310 cloned isolates evaluated, 8 were substantially attenuated compared to the low-passage Cux-1 virus pool. It is concluded that the individual virus variants comprising the P310 virus pool differ with regards to their antigenicity and pathogenicity.
鸡贫血病毒（CAV）的Cux-1分离株经过310次（P310）细胞培养传代后，其致病性明显低于传代13次（P13）的病毒。使用重组DNA克隆和转染程序从P310和P13病毒群体中筛选出的分子克隆病毒分离株，与针对低传代Cux-1病毒产生的4种CAV特异性单克隆抗体（MAb）反应不同。与所有测试的P13克隆分离株表现出的强免疫荧光（IF）反应性相反，80%和57%的P310克隆分离株与针对衣壳蛋白VP1构象表位的单克隆抗体2A9和4H4反应较弱。对10个P310和2个P13克隆分离株的VP1编码区进行序列分析表明，VP1内的6个氨基酸变化是通过多次细胞培养传代选择出来的。其中VP1第89位的一个氨基酸变化似乎对决定与单克隆抗体2A9的反应性至关重要。在评估的9个P310克隆分离株中，与低传代Cux-1病毒库相比，8个分离株明显减毒。得出的结论是，构成P310病毒库的各个病毒变体在抗原性和致病性方面存在差异。
