Genetic mobility and instability of retroviral vector in vector producer cells for gene therapy

摘要: A primary biosafety issue of retroviral vector-mediated gene therapy is the genetic instability vectors. Reverse transcription vector RNA genome initiated by viral reverse transcriptase (RT) in a virion particle after infection target celi. During transcription, abnormal template switches between and occasionally copackaged helper virus can therefore enable to regain replication elements from revert replication-competent retrovirus (RCR). This research was undertaken study origins RT enzyme activities test hypothesis that are contributed both exogenous RT, which imported re-infection virions, endogenous provided Intracellular particles. Superinfection producer cells (VPC) increase number integrated vectors VPC, mainly caused decreased Env-receptor interference, consequence inactivation host DNA methylation at 5' LTR promoter region. Suppression expression also reduces production. chimeric combined with picomavirus IRES (internal ribosome entry site) sequence selection marker constructed eliminate methylated cell populations maintain active enhance interference. Packaging established this exhibit high titer production without detectable superinfection. In addition superinfection, significant (0.2% 7.8% activity), originates precursor protein PrlSO^®^"'*", were demonstrated intracellular retrotransposition VPC. Retrotransposed integrate into different chromosomal locations plasticity VPC as observed