Eble B E, Corash L
Department of Laboratory Medicine, University of California, San Francisco 94143-0100, USA.
Photochem Photobiol. 1998 Jun;67(6):700-13.
Photochemical inactivation (PCI) of virus and bacteria in platelet concentrates (PC) has been demonstrated using 8-methoxypsoralen (8-MOP) and long-wavelength UV light (UVA). To study inactivation of blood-borne virus, we have employed duck hepatitis B virus (DHBV), a model for human hepatitis B virus. A specific hepatocyte culture infectivity assay, with PCR detection, could measure 5-6 log10 virus kill. The DHBV inactivation in PC was dependent on UVA dose, was enhanced when plasma was reduced from 100% to 20% and was limited by 8-MOP solubility in the reduced-plasma medium. Optimum conditions for PCI were 100 micrograms/mL 8-MOP in 20% plasma and 80% synthetic platelet storage medium. A radiolabeling assay for 8-MOP photoadducts in hepatocytes seeded into PC confirmed that DHBV inactivation reflected DNA modification and indicated that adduct formation was insensitive to minor variations in conditions. Kinetic modeling indicated that optimum adduct formation was a compromise between 8-MOP dark binding and optical transmittance and that plasma proteins competed for 8-MOP binding. The PCI results in various media correlated with corresponding DNA modification densities and were compared to statistical models incorporating DHBV characteristics and predictions of 8-MOP crosslink formation between DNA strands. Behavior was consistent with one or a small number of lethal modifications per DNA strand, including monoadducts, but probably not crosslinks alone. A minor subpopulation of DHBV was found to be somewhat more difficult to inactivate, consistent with three-fold lower modification, due possibly to single-stranded DNA character or host repair of photoadducts.
使用8-甲氧基补骨脂素（8-MOP）和长波紫外线（UVA）已证明可对血小板浓缩物（PC）中的病毒和细菌进行光化学灭活（PCI）。为了研究血源病毒的灭活情况，我们采用了鸭乙型肝炎病毒（DHBV），它是人类乙型肝炎病毒的一种模型。一种特定的肝细胞培养感染性测定法，结合PCR检测，能够检测到5-6个对数级的病毒杀灭情况。PC中DHBV的灭活取决于UVA剂量，当血浆从100%降至20%时灭活作用增强，且受8-MOP在低血浆培养基中溶解度的限制。PCI的最佳条件是在20%血浆和80%合成血小板储存培养基中加入100微克/毫升的8-MOP。对接种到PC中的肝细胞进行的8-MOP光加合物放射性标记测定证实，DHBV的灭活反映了DNA修饰，并表明加合物形成对条件的微小变化不敏感。动力学模型表明，最佳加合物形成是8-MOP暗结合与光透射率之间的一种折衷，且血浆蛋白会竞争8-MOP的结合。在各种培养基中的PCI结果与相应的DNA修饰密度相关，并与纳入DHBV特征和DNA链间8-MOP交联形成预测的统计模型进行了比较。其行为与每条DNA链一个或少量致死性修饰一致，包括单加合物，但可能不只是交联。发现一小部分DHBV较难灭活，这与修饰降低三倍一致，可能是由于单链DNA特性或光加合物的宿主修复。
