中国猕猴预存抗腺病毒中和抗体滴度对腺病毒体外感染单核细胞效率的影响

Monocytes Are More Susceptible in vitro in Rhesus Macaques of Chinese Origin to Recombinant Serotype 5 Adenovirus with Higher Preexisting Vector Specific Neutralizing Antibody Titer

为了探索通过血液系统利用重组腺病毒载体的方法,以中国猕猴为动物模型,以复制缺陷型人5型腺病毒(human adenovirus serotype 5,HAd 5)为载体携带报告基因在体外直接感染外周血单个核细胞(peripheral blood mononuclear cells,PBMC)。首先对HAd5在体外感染PBMC的条件进行优化,证实离心力可提高HAd5的感染效率;细胞分群结果表明HAd5特异感染PBMC中的CD14+单核细胞,仅感染小部分自然杀伤细胞,但几乎不感染T淋巴细胞和B淋巴细胞。首次发现:猕猴体内预先存在的抗HAd5中和抗体滴度越高,其单核细胞在体外对HAd5的易感性越强。这种现象将拓宽基于腺病毒载体的基因治疗和疫苗的临床应用范围,尤其是对预先存在腺病毒中和抗体的人群更具意义,为探索更方便有效的基因治疗和疫苗研究带来新的思考。

Human adenovirus serotype 5 （HAdS） infect dendritic cells with low efficiency which restricts the use of HAd5 as an antigen carrying vector in such cells. Aiming to find a novel strategy to detour the traditional method for more convenient clinical use, peripheral blood mononuclear cells isolated from Chinese rhesus macaques were chosen as the target cells for HAd5. In vitro infection protocol was optimized which indicated centrifugation at 1000g could ease the entry of adenovirus. By this protocol, CD14 positive monocytes were infected at high efficiencies （〉80%）, and about 10% of natural killer cells were infected; while T and B lymphocytes were rarely infected. Interestingly and importantly, it was the first time to report that in our in vitro study monocytes were more susceptible to HAd5-EGFP in macaques with higher preexisting vector specific neutralizing antibody titers. This phenomenon indicates an expansion of application of adenovirus based vectors for vaccine development and clinical use, especially for the population with preexisting neutralizing antibodies.