摘要
目的:Palivizum ab(PZ)是目前唯一用于防治感染性疾病的单克隆抗体药物,主要用于预防高危患儿RSV感染。体外筛选获得的PZ逃逸株F基因发生众多突变,且在棉鼠体内完全抵抗大剂量PZ预防效应。本研究评估RSV PZ逃逸株在动物体内是否出现。方法:用环磷酰胺(CY)腹腔注射法制备免疫抑制棉鼠模型,鼻腔接种病毒前24h或后6周肌注15m g/kg PZ。感染后12周收集棉鼠肺脏,用逆转录PCR法扩增RSV F基因片断并克隆入质粒载体,测定克隆cDNA序列筛查F基因突变。结果:在5只接受PZ预防或治疗的棉鼠中,3只棉鼠肺内病毒为含有逃逸株和原型株的混合群体;来自上述3只棉鼠的F基因cDNA克隆中,超过50%显示与体外PZ逃逸株相同的F基因突变。从其中1只棉鼠肺脏中分离的病毒抵抗PZ中和效应。结论:RSV在环磷酰胺处理的棉鼠模型肺内复制时间明显延长,在PZ筛选压力存在情况下,PZ逃逸株可在体内产生,并可能导致PZ预防或治疗失效,提示今后有必要在PZ使用人群中长期监控逃逸株是否出现。
Objective： Palivizumab （PZ） is the only monoclonal antibody presently available for use in humans against an infectious disease. RSV selected in cell culture for growth in the presence of PZ develops F gene mutations and is resistant to PZ prophylaxis in cotton rats. Here, we evaluated the potential for PZ resistant RSV to arise in vivo. Methods： Cotton rats were immunosuppressed with cyclophosphamide （CY）, administered PZ, and inoculated intranasally with RSV. Lungs were harvested 12 weeks after RSV infection, RT-PCR amplified F gene fragments were cloned into plasmids, and the nucleotide sequences of the cloned cDNAs were determined. Results： Three of the five animals had mixed populations of lung viruses, and over 50% of the clones from the 3 animals revealed F gene mutations associated with resistance to PZ. A virus completely resistant to PZ neutralization was recovered from the lung homogenate of a rat that had received PZ. Conclusion： Prolonged pulmonary replication of RSV in the presence of PZ is followed by the appearance of viruses resistant to PZ. The potential for the development of resistance is a consideration as antibody is used prophylactically against RSV and as passively administered antibody is under development for other infections, including emerging viruses and agents of biodefense.
出处
《重庆医科大学学报》
CAS
CSCD
2006年第1期5-9,18,共6页
Journal of Chongqing Medical University
基金
美国国立卫生研究院NIHGrantR01AI46495
关键词
呼吸道合胞病毒
逃逸株
单克隆抗体
免疫抑制
动物模型
Respiratory syncytial virus
Escape mutant
Monoclonal antibody
Immunosuppression
Animal model
