Periodic Reporting for period 4 - LeukoTheranostics (Harnessing Targeted Nanotheranostics to Reprogram Activated Leukocytes in Inflammatory Bowel Disease) Reporting period: 2020-05-01 to 2021-10-31 Summary of the context and overall objectives of the project Inflammatory bowel diseases (IBD) comprises a group of chronic inflammations of the gastro-intestinal tract. The two main types are Crohn's Disease and Ulcerative Colitis. While IBD has been extensively studied in the past decades and especially recently since emerging technologies enabled DNA sequencing of intestinal bacteria, the development of new treatments have been progressing slowly. Only recently, some more specific therapies like antibodies that target leukocytes’ trafficking (e.g. against α4β7 integrin) or against pro-inflammatory cytokines (e.g. anti- TNF-α) are being used. Because of the complexity of intestinal immunity, we believe that a tailor-made therapy is required. We are working on a project that targets lipid nanoparticles (LNPs) specifically to immune cells actively participating in the intestinal inflammation. We do this by coating the LNPs with a protein that contains part of MAdCAM-1, the natural ligand of α4β7 integrin. This ligand recognizes only the high-affinity conformation of α4β7 integrin, a conformation that enables immune cells to migrate to the gut. Using this system, we show that we can deliver therapeutic siRNAs specifically to these cells while leaving other cells untouched.The incidence of IBD in Europe is rising (> 1% of the EU suffer from IBD) and with it, its associated healthcare costs (~ 5 billion euro/year in 2013). Novel therapeutics like Humera and Entyvio are promising drugs but leave patients dependent on expensive monoclonal antibodies for a long period. We envision manipulating pro-inflammatory immune cells by silencing specific target genes and thereby we strive to restore the natural immunological balance.As a result of this project, we also developed a strategy to immobilize mAb on the surface of lipid nanoparticles and control the orientation of the mAb on the LNPs’ surface. Using this approach we should systemic, cell specific delivery of siRNAs to leukocytes subsets (Kedmi R. et al. Nature Nanotechnology 2018; Dammes N. et al., Nature Nanotechnology 2021). In addition, we utilize this approach to show the first, systemic, cell specific delivery of mRNA into leukocytes (Viega et al. Nature Communications 2018; Veiga N. et al Journal of controlled release 2019) and the first systemic, therapeutic genome editing in cancer (Rosenblum D. et al Science Adv. 2020). The main objective of this project is to deliver siRNA against a pro-inflammatory target (e.g. IFN-γ or TNF-α) in vivo in a colitis mouse model and achieve therapeutic efficacy. Furthermore, we are developing more accurate diagnostic and disease management tools by labeling the activated immune cells with Cu64 in out targeted LNPs to analyze the disease with PET/CT Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far The main results include the design, production and purification of a recombinant protein containing essential binding domains for Fc of any antibody from the same isotype, a kind of a universal linker (The ASSET platform) that could be used as a targeting strategy for any mAb or fusion protein to any cell surface receptor. This strategy opened new avenoues in in vivo cell specific delivery of RNA payloads including siRNAs, mRNA and combination of mRNA and sgRNA for in vivo selective high efficiency genome editing (publications include: Kedmi R. et al. Nature Nanotechnology 2018; Veiga N. et al. Nature Communications 2018; Veig N. et al Journal of Controlled Release 2019; Rosenblum D. et al. Science Adv. 2020). A specific strategy to target specific activation dependent conformation of α4β7 integrin was developed (Dammes N. et al Nature Communications 2021). We characterized and optimized the binding to immune cells in vitro and achieved in vivo gene silencing of a reporter gene in experimental colitis model. We also developed this strategy for highly selective molecular imaging using microPET/CT in colitis and identify a new class of immune cells that can be manipulated via siRNAs and imaged in the early onset of the colitis (Dammes N. et al. Nature Nanotechnology 2021). Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far) We have demonstrated the use of our ASSET strategy as a universal linker to target specific cell types with different payloads (siRNAs – as originally planned in 2014 grant proposal; mRNA (2018) and CRISPR/CAS9 (2020)) in different animal model beyond IBD (also cancer in several animal models). We progress the field of mRNA and genome editing showing the first in vivo, cell specific delivery of mRNA in animals (Viega N. et al. Nature Communications 2018) and the firast systemic cell specific therapeutic genome editing in cancer (Rosenblum D. et al. Science Adv. 2020). We exemplified the use of conformation sensitive approach in IBD in a theranostic strategy using a high end highly specific molecular imaging (microPET/CT) in IBD (Dammes N. et al. Nature Nanotechnology 2021). With this strategy we identify a new class of T cells that can be manipulated with siRNA against IFNg and influence the gut microenviroment in a chronic IBD mouse model (IL10KO model).In addition, we were able to identify the disease onset in IBD tracking these small subset of leukocytes using a specific targeting approach with 64Cu-labeled LNPs. This could be also used in disease management. These strategies have been validated with novel lipids we also developed and was licensed by BioNtech in Germany in 2018 and are now in clinical development. https://ramot.org/news/2018/ramot-and-biontech-sign-license-agreement-to-use-novel-set-of-lipids-for-improved-mrna-delivery nuphar-review-1024x828.jpg
