a-step-step-method-to-detect-neutralizing-antibodies-against-aav

A Step-By-Step Method to Detect Neutralizing Antibodies Against AAV using a Colorimetric Cell-Based Assay

Recombinant adeno-associated viruses (rAAV) have proven to be a safe and successful vector for transferring genetic material to treat various health ...

Baker Heart and Diabetes Institute

La Trobe University

Despite advances in treatment over the past decade, heart failure remains a significant public health burden and a leading cause of death in the developed world. Gene therapy provides a promising approach for preventing and reversing cardiac abnormalities, however, clinical application has shown limited success to date. A substantial effort is being invested into the development of recombinant adeno-associated viruses (AAVs) for cardiac gene therapy as AAV gene therapy offers a high safety profile and provides sustained and efficient transgene expression following a once-off administration. Due to the physiological, anatomical and genetic similarities between large animals and humans, preclinical studies using large animal models for AAV gene therapy are crucial stepping stones between the laboratory and the clinic. Many molecular targets selected to treat heart failure using AAV gene therapy have been chosen because of their potential to regulate and restore cardiac contractility. Other genes targeted with AAV are involved with regulating angiogenesis, beta-adrenergic sensitivity, inflammation, physiological signalling and metabolism. While significant progress continues to be made in the field of AAV cardiac gene therapy, challenges remain in overcoming host neutralising antibodies, improving AAV vector cardiac-transduction efficiency and selectivity, and optimising the dose, route and method of delivery.

Adeno-Associated Virus Gene Therapy: Translational Progress and Future Prospects in the Treatment of Heart Failure.

Open-access gene expression data sets provide a useful resource for identifying novel drug targets and biomarkers. The IGF1-PI3K pathway is a critical mediator of physiological cardiac enlargement/hypertrophy and protection. This study arose after mining a gene microarray data set from a previous study that compared heart tissue from cardiac-specific PI3K transgenic mouse models. The top-ranked candidate identified from the microarray data was clusterin. Clusterin has been proposed as a biomarker for multiple diseases including heart failure, and as a cancer drug target. Here, we show that clusterin gene expression is increased in hearts of transgenic mice with increased PI3K and decreased in mice with depressed cardiac PI3K. In vitro, clusterin secretion was elevated in media from neonatal rat ventricular myocytes treated with IGF1. Furthermore, by mining gene expression data from hearts during normal mouse postnatal growth, we also report an increase in clusterin expression with postnatal heart growth. Given we show that clusterin is regulated by the IGF1-PI3K pathway in the heart, and this pathway mediates physiological cardiac hypertrophy and cardioprotection, caution is required when considering clusterin as a biomarker for heart failure and as a cancer target. Mining pre-existing cardiac profiling data sets may be a useful approach to assess whether regulating new drug targets is likely to lead to cardiac damage/toxicity.

Clusterin is regulated by IGF1-PI3K signaling in the heart: implications for biomarker and drug target discovery, and cardiotoxicity.

Heart failure represents the end point of a variety of cardiovascular diseases. It is a growing health burden and a leading cause of death worldwide. To date, limited treatment options exist for the treatment of heart failure, but exercise has been well-established as one of the few safe and effective interventions, leading to improved outcomes in patients. However, a lack of patient adherence remains a significant barrier in the implementation of exercise-based therapy for the treatment of heart failure. The insulin-like growth factor 1 (IGF1)-phosphoinositide 3-kinase (PI3K) pathway has been recognized as perhaps the most critical pathway for mediating exercised-induced heart growth and protection. Here, we discuss how modulating activity of the IGF1-PI3K pathway may be a valuable approach for the development of therapies that mimic the protective effects of exercise on the heart. We outline some of the promising approaches being investigated that utilize PI3K-based therapy for the treatment of heart failure. We discuss the implications for cardiac pathology and cardiotoxicity that arise in a setting of reduced PI3K activity. Finally, we discuss the use of animal models of cardiac health and disease, and genetic mice with increased or decreased cardiac PI3K activity for the discovery of novel drug targets and biomarkers of cardiovascular disease.

Sebastian Bass-Stringer

Baker Heart and Diabetes Institute

A Step-By-Step Method to Detect Neutralizing Antibodies Against AAV using a Colorimetric Cell-Based Assay