Mechanistic investigation of immunotoxicity associated with Adeno-associated virus vector-based gene therapy

Description

Adeno-associated virus (AAV) vector-based gene therapies have revolutionised medicine, offering life-changing efficacy for various diseases, including AAV2-based Luxturna for previous medically untreatable retinal dystrophy, AAV9-based Zolgensma for spinal muscular atrophy, and AA5-based Hemgenix for hemophilia. However, immune responses against the AAV capsid present significant challenge to the safety and efficacy of AAV gene therapy. Since humans are naturally exposed to wild-type AAV, an estimated 30–70% of individuals have pre-existing immunity, such as AAV-specific neutralizing antibodies, which can substantially reduce therapeutic efficacy. Additionally, severe adverse events including liver toxicity and thrombotic microangiopathy have been linked with AAV-specific B cell and T cell responses. Therefore, better understanding of AAV immunogenicity is crucial for reducing AAV immunogenicity and developing safer and more effective gene therapies.

This multidisciplinary project aims to develop a platform to identify neoantigens derived from AAV vectors that are presented by common HLA alleles, evaluate the immunogenicity of AAV HLA ligands, and mechanistic evaluation of AAV-responsive T-cell activation. In this project, we will characterise immunodominant T-cell epitopes (class I and class II) shared across different AAV serotypes AAV2, AAV5 and AAV9 complete capsid vectors using monocyte-derived dendritic cells (MDDCs) from a panel of healthy donors representing a broad range of alleles. Furthermore, comprehensive in vitro T-cell assays will be used to detect cross-reactive, memory T-cells responsive to AAV antigens using PBMCs from healthy donors and patients with AAV immunotoxicity. To better understand how AAV antigens stimulate T-cells, AAV-responsive T-cell clones will be generated using PBMCs from healthy donors and patients with immunotoxicity to characterise cellular phenotype, tissue homing receptors, and function (cytokine release, migration of clones towards chemokines, cytotoxicity). Across patient and healthy donor groups, cross-reactivity studies will also be performed to assess the specificity of T-cells to individual peptide epitopes.

This project will utilise our world-class facilities including proteomics and cell culturing of human primary cells. The student will be based in the immunopharmacology group led by Prof Naisbitt (X: @ImmunoPharm) and Dr Meng (X: @xl_meng) at the Pharmacology department, University of Liverpool. The student will receive training in a wide variety of techniques including proteomics, and advanced primary cell culturing. An industrial placement at AstraZeneca will also provide the student with opportunity to gain hands-on experience in immunotoxicity assessment within real-world drug development. Furthermore, this multi-disciplinary training will give the student a broad range of skills allowing a wide choice of career options, both within and outside of academia, after the PhD.

For informal enquiries about the project, please contact Dr Meng (xlmeng@Liverpool.ac.uk).