van Dijk R, Montenegro-Miranda PS, Riviere C, Schilderink R, ten Bloemendaal L, van Gorp J, Duijst S, de Waart DR, Beuers U, Haisma HJ, Bosma PJ. Polyinosinic acid blocks adeno-associated virus macrophage endocytosis in vitro and enhances adeno-associated virus liver-directed gene therapy in vivo.
Hum Gene Ther 2014;
24:807-13. [PMID:
24010701 DOI:
10.1089/hum.2013.086]
[Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Adeno-associated virus serotype 8 (AAV8) has been demonstrated to be effective for liver-directed gene therapy in humans. Although hepatocytes are the main target cell for AAV8, there is a loss of the viral vector because of uptake by macrophages and Kupffer cells. Reducing this loss would increase the efficacy of viral gene therapy and allow a dose reduction. The receptor mediating this uptake has not been identified; a potential candidate seems the macrophage scavenger receptor A (SR-A) that is involved in the endocytosis of, for instance, adenovirus. In this study we show that SR-A can mediate scAAV8 endocytosis and that blocking it with polyinosinic acid (poly[i]) reduces endocytosis significantly in vitro. Subsequently, we demonstrate that blocking this receptor improves scAAV-mediated liver-directed gene therapy in a model for inherited hyperbilirubinemia, the uridine diphospho-glucuronyl transferase 1A1-deficient Gunn rat. In male rats, preadministration of poly[i] increases the efficacy of a low dose (1×10¹¹ gc/kg) but not of a higher dose (3×10¹¹ gc/kg) scAAV8-LP1-UT1A1. Administration of poly[i] just before the vector significantly increases the correction of serum bilirubin in female rats. In these, the effect of poly[i] is seen by both doses but is more pronounced in the females receiving the low vector, where it also results in a significant increase of bilirubin glucuronides in bile. In conclusion, this study shows that SR-A mediates the endocytosis of AAV8 in vitro and in vivo and that blocking this receptor can improve the efficacy of AAV-mediated liver-directed gene therapy.
Collapse