Biology subjects

Adjali, O.

Publications and source records attributed to Adjali, O..

4 recordsLinked to original sources

bioRxiv2024

Advancing Liver Gene Therapy: Enhanced Transduction with GalNAc-Bioconjugated rAAV Capsids

This study investigates novel approaches to improve targeted gene delivery to the liver, a crucial organ for metabolic processes that faces vulnerabilities from various pathologies. Adeno-associated virus (AAV)-based gene therapy has emerged as a promising approach for liver targeting, with numerous investigational avenues. However, administration of high doses of AAV vectors present safety concerns, often requiring the use of corticosteroids and immunosuppression to mitigate immune adverse events. To address this, substantial efforts are underway to engineer optimized capsids to enhance the efficiency and specificity of recombinant AAV (rAAV) targeting hepatocytes, aiming to reduce required dosages. In this study, we employed bioconjugation chemistry to target the Asialoglycoprotein receptor (ASGPR), a C-type lectin abundantly expressed at the surface of hepatocyte membranes. We demonstrated that covalently attaching carbohydrates derived from GalNAc (a known ASGPR ligand) to lysine amino-acids on the rAAV2 capsid significantly enhanced in vivo liver transduction efficiency in mice. These optimized vectors present a promising avenue for the treatment of a spectrum of liver diseases, providing an alternative solution within the framework of liver gene therapy.

bioengineering↗

bioRxiv2023

Prevalence study of cellular capsid-specific immune responses to AAV1, 2, 4, 5, 8, 9 and rh10 reveals particular features for AAV9

Recombinant adeno-associated virus (rAAV) vectors appear, more than ever, to be efficient viral vectors for in vivo gene transfer as illustrated by the approvals of 7 drugs across Europe and the USA. Nevertheless, pre-existing immunity to AAV capsid in humans remains one of the major limits for a successful clinical translation. Whereas pre-existing humoral response to AAV capsid is well documented, the prevalence of pre-existing capsid-specific T cell responses still needs to be studied and characterized. Here, we investigated the prevalence of AAV-specific circulating T cells towards AAV2, 4, 5, 8, 9 and rh10 in a large cohort of healthy donors using the standard IFN{gamma} ELISpot assay. We observed the highest prevalence of pre-existing cellular immunity to AAV9 serotype followed by AAV8, AAV4, AAV2, AAVrh10 and AAV5 independently of the donors serological status. An in-depth analysis of T cell responses towards the 2 most prevalent serotypes 8 and 9 shows that IFN{gamma} secretion is mainly mediated by CD8 T cells for both serotypes. A polyfunctional analysis reveals different cytokine profiles between AAV8 and AAV9. Surprisingly, no IL-2 secretion was mediated by anti-AAV9 immune cells suggesting that these cells may rather be exhausted or terminally differentiated than cytotoxic T cells. Altogether, these results suggest that pre-existing immunity to AAV may vary depending on the serotype and support the necessity of using multiparametric monitoring methods to better characterize anti-capsid cellular immunity and foresee its impact in rAAV-mediated clinical trials.

immunology↗

bioRxiv2023

Dystrophin deficiency impairs cell junction formation during embryonic myogenesis

Mutations in the DMD gene lead to Duchenne muscular dystrophy, a severe X-linked neuromuscular disorder that manifests itself as young boys acquire motor functions. DMD is typically diagnosed at 2 to 4 years of age, but the absence of dystrophin negatively impacts muscle structure and function before overt symptoms appear in patients, which poses a serious challenge in the optimization of standards of care. In this report, we investigated the early consequences of dystrophin deficiency during skeletal muscle development. We used single-cell transcriptome profiling to characterize the myogenic trajectory of human pluripotent stem cells and showed that DMD cells bifurcate to an alternative branch when they reach the somite stage. Here, dystrophin deficiency was linked to marked dysregulations of cell junction protein families involved in the cell state transitions characteristic of embryonic somitogenesis. Altogether, this work demonstrates that in vitro, dystrophin deficiency has deleterious effects on cell-cell communication during myogenic development, which should be considered in future therapeutic strategies for DMD.

pathology↗

bioRxiv2022

Mannose-coupled AAV2: a second generation AAV vector for increased retinal gene therapy efficiency

Inherited retinal diseases are a leading and untreatable cause of blindness and are therefore candidate diseases for gene therapy. Recombinant vectors derived from adeno-associated virus (rAAV) are currently the most promising vehicles for in vivo therapeutic gene delivery to the retina. However, there is a need for novel AAV-based vectors with greater efficacy for ophthalmic applications, as underscored by recent reports of dose-related inflammatory responses in clinical trials of rAAV-based ocular gene therapies. Improved therapeutic efficacy of vectors would allow for decreases in the dose delivered, with consequent reductions in immune reactions. Here, we describe the development of new rAAV vectors using bioconjugation chemistry to modify the rAAV capsid, thereby improving the therapeutic index. Covalent coupling of a mannose ligand, via the formation of a thiourea bond, to the amino groups of the rAAV capsid significantly increases vector transduction efficiency of both rat and nonhuman primate retinas. These optimized rAAV vectors have important implications for the treatment of a wide range of retinal diseases.

bioengineering↗