Anti-AAV type 2, 3, 6 Polyclonal antibody

The gene therapy field has been galvanized by two technologies that have revolutionized treating genetic diseases: vectors based on adeno-associated viruses (AAVs), and clustered regularly interspaced short palindromic repeats (CRISPR)-Cas gene-editing tools. When combined into one platform, these safe and broadly tropic biotherapies can be engineered to target any region in the human genome to correct genetic flaws. Unfortunately, few investigations into the design compatibility of CRISPR components in AAV vectors exist. Using AAV-genome population sequencing (AAV-GPseq), we previously found that self-complementary AAV vector designs with strong DNA secondary structures can cause a high degree of truncation events, impacting production and vector efficacy. We hypothesized that the single-guide RNA (sgRNA) scaffold, which contains several loop regions, may also compromise vector integrity. We have therefore advanced the AAV-GPseq method to also interrogate single-strand AAV vectors to investigate whether vector genomes carrying Cas9-sgRNA cassettes can cause truncation events. We found that on their own, sgRNA sequences do not produce a high degree of truncation events. However, we demonstrate that vector genome designs that carry dual sgRNA expression cassettes in tail-to-tail configurations lead to truncations. In addition, we revealed that heterogeneity in inverted terminal repeat sequences in the form of regional deletions inherent to certain AAV vector plasmids can be interrogated.

Eosinophilic granulomatosis with polyangiitis (EGPA, formerly Churg-Strauss syndrome) is the least frequent antineutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV). Major advances of our knowledge on its pathophysiology have revealed features of both AAV and eosinophilic disorders. The development of targeted biotherapies for both diseases opened new possibilities for EGPA management. In this review, we highlight the rationale underlying the routine treatment strategy, which relies mainly on corticosteroids, with immunosuppressant adjunction for severe disease. However, novel therapies are still needed for refractory/relapsing disease and to alleviate the corticosteroid-dependence of asthma and chronic rhinosinusitis. At present, the most promising biotherapies target either eosinophil biology, like mepolizumab, an anti-interleukin-5, or the B-cell compartment, with rituximab. Recent clinical data on new treatment options are discussed and therapeutic strategies are proposed. (C) 2020 Elsevier Masson SAS. All rights reserved.