Gene and RNA Therapy Center (GRTC)

Molecular Therapies for Inherited Retinal Dystrophies and Optic Neuropathies

The eye bears a number of important advantages for the development, application and testing of innovative therapies. Consequently, ocular disease such as inherited retinal dystrophies and optic neuropathies are amongst the forerunners in molecular therapy development.
Beyond our contribution to in-house clinical translation programs in supplementation gene therapy for inherited retinal disorders (IRDs), we are exploring and developing innovative genome-editing approaches, which offer safer profile and overcome most of the current hurdles (e.g. use of multiple gRNAs, over activation of P53 pathways, chromosomal aberrations etc.). Specifically, we are applying Enhanced-Deletion RNA-guided endonuclease molecules coupled to single gRNAs to rescue aberrant splicing due to pathogenic (deep-) intronic variants in important IRD genes (ABCA4 and USH2A) as well as to selectively disrupt mutant RHO alleles linked to dominant inherited Retinitis Pigmentosa. Such editing approaches are preclinically validated in patient-derived cellular models. Moreover, we exploit antisense oligonucleotides as therapeutic agents to rescue certain splicing defects linked to IRDs and inherited optic neuropathies.

GRT projects

• CRISPR/Enhanced-Deletion Cas9-mediated allele-specific targeting of the rhodopsin gene: a novel mutation-independent approach to treat RHO-linked autosomal dominant Retinitis pigmentosa
• Rescuing deep intronic mutations in retinal disease genes (ABCA4, USH2A) by innovative EDCas9 Genome Editing
• Antisense oligonucleotide-mediated ablation of mutant rhodopsin
• Antisense oligonucleotide-mediated rescue of exonic splicing mutations in the human cone opsin genes 

 GRT expertise

• Genome editing mediated by CRISPR/Cas molecules
• Engineering of Cas molecules
• Antisense oligonucleotides

 Main GRT methods applied in the lab

• Lab-scale Lentivirus production
• Somatic reprogramming into iPSCs
• Differentiation of iPSCs (ie. Photoreceptor precursor cells)
• CRISPR/Cas-mediated knock in
• Antisense oligonucleotide (in vitro assays) 
• High-throughput sequencing (editing profiles)
• Establishment of reporter cell systems

Ongoing and requested funding

• DFG – Schwerpunktprogramm 2127
  CRISPR/Enhanced-Deletion Cas9-mediated allele-specific targeting of the rhodopsin gene: a novel mutation-independent approach to treat RHO-linked autosomal dominant
  Retinitis pigmentosa (Wi 1189/15-1)
  
  Selecting the right patients for gene-based therapies: Development and
  implementation of a pathogenicity scoring system combined with functional in
  vitro validation of gene variants and genotypes in patients with inherited retinal
  dystrophy as a criterion for the eligibility for therapeutic studies (KO 2176/3-2)
  
  
• Usher Syndrome Society
  Rescuing the common deep intronic USH2A variant c.7595-2144A>G by single gRNA Enhanced-Deletion Cas9 genome editing
   

Publications