Autophagy determines efficiency of liver-directed gene therapy with adeno-associated viral vectors.
Use of adeno-associated viral (AAV) vectors for liver-directed gene therapy has shown considerable success, particularly in patients with severe hemophilia B. However, the high vector doses required to reach therapeutic levels of transgene expression caused liver inflammation in some patients that selectively destroyed transduced hepatocytes. We hypothesized that such detrimental immune responses can be avoided by enhancing the efficacy of AAV vectors in hepatocytes. Because autophagy is a key liver response to environmental stresses, we characterized the impact of hepatic autophagy on AAV infection. We found that AAV induced mammalian target of rapamycin (mTOR)-dependent autophagy in human hepatocytes. This cell response was critically required for efficient transduction because under conditions of impaired autophagy (pharmacological inhibition, small interfering RNA knockdown of autophagic proteins, or suppression by food intake), recombinant AAV-mediated transgene expression was markedly reduced, both in vitro and in vivo. Taking advantage of this dependence, we employed pharmacological inducers of autophagy to increase the level of autophagy. This resulted in greatly improved transduction efficiency of AAV vectors in human and mouse hepatocytes independent of the transgene, driving promoter, or AAV serotype and was subsequently confirmed in vivo. Specifically, short-term treatment with a single dose of torin 1 significantly increased vector-mediated hepatic expression of erythropoietin in C57BL/6 mice. Similarly, coadministration of rapamycin with AAV vectors resulted in markedly enhanced expression of human acid-α-glucosidase in nonhuman primates.



We identified autophagy as a pivotal cell response determining the efficiency of AAVs intracellular processing in hepatocytes and thus the outcome of liver-directed gene therapy using AAV vectors and showed in a proof-of-principle study how this virus-host interaction can be employed to enhance efficacy of this vector system. (Hepatology 2017;66:252-265).
Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.|German Center for Infection Research (DZIF), Partner sites Bonn-Cologne and Hannover-Braunschweig, Germany.
Marianna
M
Hösel
Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.|German Center for Infection Research (DZIF), Partner sites Bonn-Cologne and Hannover-Braunschweig, Germany.
Anke
A
Huber
Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Cologne, Germany.
Susanne
S
Bohlen
INSERM, U1052, Cancer Research Center of Lyon (CRCL), University of Lyon, Lyon, France.
Julie
J
Lucifora
Genethon and INSERM U951, Evry, France.
Giuseppe
G
Ronzitti
Genethon and INSERM U951, Evry, France.
Francesco
F
Puzzo
Genethon and INSERM U951, Evry, France.
Florence
F
Boisgerault
University Medicine Leipzig, University Cancer Center Leipzig (UCCL), Leipzig, Germany.
Ulrich T
UT
Hacker
Laboratory of Experimental Medicine and Pediatrics (LEMP), University of Antwerp, Antwerp, Belgium.
Wilhelmus J
0000-0001-9474-6695
WJ
Kwanten
IFB Adiposity Diseases, University of Leipzig, Leipzig, Germany.
Nora
N
Klöting
Department of Medicine, University of Leipzig, Leipzig, Germany.
Matthias
M
Blüher
Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.|Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Cologne, Germany.
Alexander
A
Gluschko
Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.|Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Cologne, Germany.
Michael
M
Schramm
Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.|Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Cologne, Germany.
Olaf
O
Utermöhlen
Department of Molecular and Cellular Sport Medicine, German Sport University Cologne, Cologne, Germany.
Wilhelm
W
Bloch
Genethon and INSERM U951, Evry, France.|University Pierre and Marie Curie, Paris, France.
Federico
F
Mingozzi
Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Cologne, Germany.
Oleg
O
Krut
Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.|German Center for Infection Research (DZIF), Partner sites Bonn-Cologne and Hannover-Braunschweig, Germany.|Institute of Experimental Hematology, Hannover Medical School, Hannover, Germany.
Hildegard
H
Büning
D000818:Animals; D001343:Autophagy / Q000235:genetics*; D002478:Cells, Cultured; D000229:Dependovirus / Q000235:genetics*; D004195:Disease Models, Animal; D005260:Female; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D022781:Hepatocytes / Q000166:cytology*; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D011897:Random Allocation; D014161:Transduction, Genetic