Lyons Mark, Onion David, Green Nicky K, Aslan Kriss, Rajaratnam Ratna, Bazan-Peregrino Miriam, Phipps Sue, Hale Sarah, Mautner Vivien, Seymour Leonard W, Fisher Kerry D
Department of Clinical Pharmacology, University of Oxford, Radcliffe Infirmary, Woodstock Road, Oxford OX2 6HE, UK.
Mol Ther. 2006 Jul;14(1):118-28. doi: 10.1016/j.ymthe.2006.01.003. Epub 2006 Mar 31.
Intravenous delivery of adenovirus vectors requires that the virus is not inactivated in the bloodstream. Serum neutralizing activity is well documented, but we show here that type 5 adenovirus also interacts with human blood cells. Over 90% of a typical virus dose binds to human (but not murine) erythrocytes ex vivo, and samples from a patient administered adenovirus in a clinical trial showed that over 98% of viral DNA in the blood was cell associated. In contrast, nearly all viral genomes in the murine bloodstream are free in the plasma. Adenovirus bound to human blood cells fails to infect A549 lung carcinoma cells, although dilution to below 1.7 x 10(7) blood cells/ml relieves this inhibition. Addition of blood cells can prevent infection by adenovirus that has been prebound to A549 cells. Adenovirus also associates with human neutrophils and monocytes ex vivo, particularly in the presence of autologous plasma, giving dose-dependent transgene expression in CD14-positive monocytes. Finally, although plasma with a high neutralizing titer (defined on A549 cells) inhibits monocyte infection, weakly neutralizing plasma can actually enhance monocyte transduction. This may increase antigen presentation following intravenous injection, while blood cell binding may both decrease access of the virus to extravascular targets and inhibit infection of cells to which the virus does gain access.
腺病毒载体的静脉内递送要求病毒在血流中不被灭活。血清中和活性已有充分记录，但我们在此表明5型腺病毒也与人血细胞相互作用。在体外，典型病毒剂量的90%以上与人类（而非小鼠）红细胞结合，一项临床试验中接受腺病毒治疗的患者样本显示，血液中超过98%的病毒DNA与细胞相关。相比之下，小鼠血流中的几乎所有病毒基因组在血浆中都是游离的。与人类血细胞结合的腺病毒无法感染A549肺癌细胞，尽管稀释至低于1.7×10⁷个血细胞/毫升可缓解这种抑制作用。添加血细胞可阻止已预先结合到A549细胞上的腺病毒感染。腺病毒在体外也与人中性粒细胞和单核细胞结合，尤其是在存在自体血浆时，可在CD14阳性单核细胞中产生剂量依赖性的转基因表达。最后，尽管具有高中和效价（以A549细胞定义）的血浆会抑制单核细胞感染，但弱中和血浆实际上可增强单核细胞转导。这可能会增加静脉注射后的抗原呈递，而血细胞结合可能既会减少病毒进入血管外靶标的机会，又会抑制病毒确实进入的细胞的感染。
