Gahéry-Ségard H, Farace F, Godfrin D, Gaston J, Lengagne R, Tursz T, Boulanger P, Guillet J G
Laboratoire d'Immunologie des Pathologies Infectieuses et Tumorales, INSERM Unité 445, Institut Cochin de Génétique Moléculaire, Université R. Descartes, Hôpital Cochin, Paris, France.
J Virol. 1998 Mar;72(3):2388-97. doi: 10.1128/JVI.72.3.2388-2397.1998.
Replication-deficient adenovirus used in humans for gene therapy induces a strong immune response to the vector, resulting in transient recombinant protein expression and the blocking of gene transfer upon a second administration. Therefore, in this study we examined in detail the capsid-specific humoral immune response in sera of patients with lung cancer who had been given one dose of a replication-defective adenovirus. We analyzed the immune response to the three major components of the viral capsid, hexon (Hx), penton base (Pb), and fiber (Fi). A longitudinal study of the humoral response assayed on adenovirus particle-coated enzyme-linked immunosorbent assay plates showed that patients had preexisting immunity to adenovirus prior to the administration of adenovirus-beta-gal. The level of the response increased in three patients after adenovirus administration and remained at a maximum after three months. One patient had a strong immune response to adenovirus prior to treatment, and this response was unaffected by adenovirus administration. Sera collected from the patients were assayed for recognition of each individual viral capsid protein to determine more precisely the molecular basis of the humoral immune response. Clear differences existed in the humoral response to the three major components of the viral capsid in serum from humans. Sequential appearance of these antibodies was observed: anti-Fi antibodies appeared first, followed by anti-Pb antibodies and then by anti-Hx antibodies. Moreover, anti-Fi antibodies preferentially recognized the native trimeric form of Fi protein, suggesting that they recognized conformational epitopes. Our results showed that sera with no neutralizing activity contained only anti-Fi antibodies. In contrast, neutralizing activity was only obtained with sera containing anti-Fi and anti-Pb antibodies. More importantly, we showed that anti-native Fi and anti-Pb antibodies had a synergistic effect on neutralization. The application of these conclusions to human gene therapy with recombinant adenovirus should lead to the development of strategies to overcome the formation of such neutralization antibodies, which have been shown to limit the efficacy of gene transfer in humans.
用于人类基因治疗的复制缺陷型腺病毒会引发针对该载体的强烈免疫反应，导致重组蛋白短暂表达，并在再次给药时阻断基因转移。因此，在本研究中，我们详细检测了接受一剂复制缺陷型腺病毒的肺癌患者血清中衣壳特异性体液免疫反应。我们分析了对病毒衣壳三个主要成分六邻体（Hx）、五邻体基座（Pb）和纤维（Fi）的免疫反应。在腺病毒颗粒包被的酶联免疫吸附测定板上对体液反应进行的纵向研究表明，患者在给予腺病毒-β-半乳糖苷之前就已对腺病毒具有预先存在的免疫力。三名患者在给予腺病毒后反应水平升高，并在三个月后保持在最高水平。一名患者在治疗前对腺病毒有强烈免疫反应，且该反应不受腺病毒给药的影响。对患者采集的血清进行检测，以确定其对每种病毒衣壳蛋白的识别情况，从而更精确地确定体液免疫反应的分子基础。人类血清中对病毒衣壳三个主要成分的体液反应存在明显差异。观察到这些抗体的顺序出现：抗-Fi抗体最先出现，其次是抗-Pb抗体，然后是抗-Hx抗体。此外，抗-Fi抗体优先识别Fi蛋白的天然三聚体形式，表明它们识别构象表位。我们的结果表明，无中和活性的血清仅含有抗-Fi抗体。相比之下，只有含有抗-Fi和抗-Pb抗体的血清才具有中和活性。更重要的是，我们表明抗天然Fi和抗-Pb抗体在中和方面具有协同作用。将这些结论应用于重组腺病毒的人类基因治疗，应能推动制定策略来克服此类中和抗体的形成，因为此类抗体已被证明会限制人类基因转移的疗效。
