title: Mir-142-3p target sequences reduce transgene-directed immunogenicity following intramuscular adeno-associated virus 1 vector-mediated gene delivery.
abstract: BACKGROUND
  Muscle represents an important tissue target for adeno-associated virus (AAV) vector-mediated gene transfer in muscular, metabolic or blood-related genetic disorders. However, several studies have demonstrated the appearance of immune responses against the transgene product after intramuscular AAV vector delivery that resulted in a limited efficacy of the treatment. Use of microRNAs that are specifically expressed in antigen-presenting cells (APCs) is a promising approach for avoiding those immune responses. Cellular mir-142-3p, which is APC-specific, is able to repress the translation of its target cellular transcripts by binding to a specific target sequences.
  
  
  METHODS
  In the present study, we explored the potential of mir-142-3p specific target sequences with respect to reducing or abolishing immune responses directed against ovalbumin (OVA), a highly immunogenic protein, expressed as transgene and delivered by AAV1 vector administered intramuscularly.
  
  
  RESULTS
  The occurrence of immune responses against OVA transgene following intramuscular delivery by AAV have been described previously and resulted in the loss of OVA protein expression. In the present study, we demonstrate that OVA protein expression was maintained when mir-142-3pT sequences were incorporated into the expression cassette. The sustained expression of OVA protein over time correlated with a reduced increase in anti-OVA antibody levels. Furthermore, no cellular infiltrates were observed in the muscle tissue when AAV1 vectors containing four or eight repeats of mir-142-3p target sequences after the OVA sequence were used.
  
  
  CONCLUSIONS
  The rising humoral and cellular immune responses against OVA protein after intramuscular delivery can be efficiently reduced by the use of mir-142-3p target sequences.
authors: Research and Development, uniQure BV, Amsterdam, The Netherlands. a.majowicz@uniqure.com
authors: Anna
authors: A
authors: Majowicz
authors: Piotr
authors: P
authors: Maczuga
authors: Karin L
authors: KL
authors: Kwikkers
authors: Sander
authors: S
authors: van der Marel
authors: Richard
authors: R
authors: van Logtenstein
authors: Harald
authors: H
authors: Petry
authors: Sander J
authors: SJ
authors: van Deventer
authors: Pavlina
authors: P
authors: Konstantinova
authors: Valerie
authors: V
authors: Ferreira
mesh_terms: D000818:Animals; D000229:Dependovirus / Q000235:genetics*; D018014:Gene Transfer Techniques; D057809:HEK293 Cells; D006801:Humans; D055261:Immunogenetic Phenomena / Q000187:drug effects*; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007273:Injections, Intramuscular; D008297:Male; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000008:administration & dosage / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D010047:Ovalbumin / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D007166:Immunosuppressive Agents; C555159:MIRN142 microRNA, human; D035683:MicroRNAs; D010047:Ovalbumin
keywords: adeno-associated virus (AAV); gene therapy; immune responses; microRNA; mir-142-3p; transgene