Smith Laura J, Schulman Lindsay A, Smith Samantha, Van Lieshout Laura, Barnes Carmen M, Behmoiras Liana, Scarpitti Meghan, Kivaa Monicah, Duong Khanh L, Benard Ludo O, Ellsworth Jeff L, Avila Nancy, Faulkner Deiby, Hayes April, Lotterhand Jason, Rivas Jose Israel, Sengooba Arnold V, Tzianabos Alec, Seymour Albert B, Francone Omar L
Homology Medicines, Inc., 1 Patriots Park, Bedford, MA 01730, USA.
Mol Ther Methods Clin Dev. 2022 Jun 30;26:224-238. doi: 10.1016/j.omtm.2022.06.013. eCollection 2022 Sep 8.
Adeno-associated viruses derived from human hematopoietic stem cells (AAVHSCs) are naturally occurring AAVs. Fifteen AAVHSCs have demonstrated broad biodistribution while displaying differences in transduction. We examine the structure-function relationships of these natural amino acid variations on cellular binding. We demonstrate that AAVHSC16 is the only AAVHSC that does not preferentially bind to terminal galactose. AAVHSC16 contains two unique amino acids, 501I and 706C, compared with other AAVHSCs. Through mutagenesis, we determined that residue 501 contributes to the lack of galactose binding. Structural analysis revealed that residue 501 is in proximity to the galactose binding pocket, hence confirming its functional role in galactose binding. Biodistribution analysis of AAVHSC16 indicated significantly less liver tropism in mice and non-human primates compared with other clade F members, likely associated with overall binding differences observed . AAVHSC16 maintained robust tropism to other key tissues in the peripheral and central nervous systems after intravenous injection, including to the brain, heart, and gastrocnemius. Importantly, AAVHSC16 did not induce elevated liver enzyme levels in non-human primates after intravenous injection at high doses. The unique glycan binding and tropism of AAVHSC16 makes this naturally occurring capsid an attractive candidate for therapies requiring less liver tropism while maintaining broad biodistribution.
源自人类造血干细胞的腺相关病毒（AAVHSCs）是天然存在的腺相关病毒。15种AAVHSCs已显示出广泛的生物分布，同时在转导方面存在差异。我们研究了这些天然氨基酸变异在细胞结合上的结构-功能关系。我们证明AAVHSC16是唯一不优先结合末端半乳糖的AAVHSC。与其他AAVHSCs相比，AAVHSC16包含两个独特的氨基酸，501I和706C。通过诱变，我们确定残基501导致了半乳糖结合的缺失。结构分析表明残基501靠近半乳糖结合口袋，从而证实了其在半乳糖结合中的功能作用。AAVHSC16的生物分布分析表明，与其他F分支成员相比，在小鼠和非人灵长类动物中其肝脏嗜性明显较低，这可能与观察到的整体结合差异有关。静脉注射后，AAVHSC16对周围和中枢神经系统的其他关键组织，包括大脑、心脏和腓肠肌，保持强大的嗜性。重要的是，高剂量静脉注射后，AAVHSC16在非人灵长类动物中未诱导肝酶水平升高。AAVHSC16独特的聚糖结合和嗜性使其成为一种有吸引力的衣壳候选物，适用于需要较低肝脏嗜性同时保持广泛生物分布的治疗。
