Voutetakis Antonis, Zheng Changyu, Mineshiba Fumi, Cotrim Ana P, Goldsmith Corinne M, Schmidt Michael, Afione Sandra, Roescher Nienke, Metzger Mark, Eckhaus Michael A, Chiorini John A, Dunbar Cynthia E, Donahue Robert E, Baum Bruce J
Gene Therapy and Therapeutics Branch, National Institute of Dental and Craniofacial Research, Department of Human Health Services, Bethesda, MD 20892, USA.
Hum Gene Ther. 2007 Feb;18(2):142-50. doi: 10.1089/hum.2006.154.
Salivary glands (SGs) are promising gene transfer targets with potential clinical applicability. Previous experiments in rodents using recombinant serotype 2 adeno-associated viral (rAAV2) vectors have demonstrated relatively stable transgene-encoded protein levels after SG gene transfer. In the present study, we examine direct SG administration of rAAV2 vectors encoding rhesus macaque erythropoietin (RhEPO) to the parotid glands of nonhuman primates using two different doses (n = 3 per group; 1 x 10(10) or 3 x 10(11) particles/gland, respectively). Gene transfer had no negative effects on general macaque physiology (e.g., weight, complete blood count, and serum chemistry). Macaques were euthanized 6 months after vector administration and complete necropsy and pathology assessments were performed, revealing no vector-related pathological lesions in any of the examined organs. In the high-dose group, RhEPO expression increased quickly (i.e., by week 1) and levels remained relatively stable both in serum and saliva until the end of the study. Serum-to-saliva ratios of RhEPO revealed secretion of the transgene product into the bloodstream, but not to the extent previously observed in mice. Furthermore, the kinetic results were not predicted by those observed in murine SGs. With respect to viral biodistribution, at necropsy vector was found overwhelmingly in the targeted parotid gland ( approximately 100 times more than levels in other tissues, most of which were similar to tissue levels in nontreated animals). We conclude that administration of modest doses of rAAV2 vectors to SGs for therapeutic purposes can be accomplished without significant or permanent injury to the targeted gland or to distant organs of nonhuman primates.
唾液腺（SGs）是具有潜在临床应用价值的理想基因转移靶点。先前在啮齿动物中使用重组2型腺相关病毒（rAAV2）载体进行的实验表明，唾液腺基因转移后转基因编码蛋白水平相对稳定。在本研究中，我们使用两种不同剂量（每组n = 3；分别为1×10¹⁰或3×10¹¹颗粒/腺体），将编码恒河猴促红细胞生成素（RhEPO）的rAAV2载体直接注入非人灵长类动物的腮腺。基因转移对猕猴的一般生理状况（如体重、全血细胞计数和血清化学指标）没有负面影响。在载体注射6个月后对猕猴实施安乐死，并进行完整的尸检和病理评估，结果显示在所检查的任何器官中均未发现与载体相关的病理损伤。在高剂量组中，RhEPO表达迅速增加（即第1周时），并且在血清和唾液中的水平在研究结束前一直保持相对稳定。RhEPO的血清与唾液比值表明转基因产物分泌到了血液中，但程度不及先前在小鼠中观察到的。此外，动力学结果无法通过在小鼠唾液腺中观察到的结果进行预测。关于病毒生物分布，在尸检时发现载体绝大多数存在于靶向的腮腺中（比其他组织中的水平高约100倍，其中大多数与未处理动物的组织水平相似）。我们得出结论，为了治疗目的向唾液腺施用适量的rAAV2载体可以在不对非人灵长类动物的靶向腺体或远处器官造成重大或永久性损伤的情况下实现。
