Australian experts have tested new gene therapies in a whole human liver. 

Gene therapy is a revolutionary approach to treating serious genetic diseases that most commonly involves replacing or repairing a faulty gene. 

In a worldwide first-of-its-kind study, a team of scientists from Children’s Medical Research Institute tested novel gene therapies in a whole human liver, with the goal of developing more effective treatments for life-threatening inherited diseases. 

One of the biggest problems that researchers are facing on their journey to bringing gene therapies from the lab bench to the clinic, is the lack of access to effective preclinical models that can be used to develop and test the new therapies – such as laboratory tests that are biologically relevant and clinically predictive before a therapy can be trialled in patients. 

These models need to faithfully reproduce human physiological conditions and intricate tissue organisation, so they can accurately predict the outcome when the therapy is administered to a patient.

Last year, CMRI’s Translational Vectorology Research Unit collaborated on a study, with a team at Royal Prince Alfred Hospital, to establish a new method of keeping a human liver alive in a lab setting. 

Livers that were not suitable for human transplantation and would have previously been discarded or kept on ice for research, are now able to be preserved outside the body at human body temperature, enabling cutting-edge biomedical research.

This is called a normothermic liver perfusion system.

The most efficient delivery systems today are those based on a harmless virus named adeno-associated virus (AAV) that has a natural ability to carry genetic information into human cells.

The CMRI team has demonstrated the potential of using their new system to test AAV-based therapeutics prior to initiation of clinical studies. 

The use of the whole human liver is a revolutionary advance in the field of gene therapy as it allows researchers to accurately test how the new therapeutics would affect a major organ, the liver - something that could not be done before.

“This is very exciting for us because now, for the first time, we can assess the function of gene therapeutics directly in the clinical target organ itself – the human liver,” said Associate Professor Leszek Lisowski, the senior author on the publication.

“This is important because the current generation of viral vectors we use to deliver gene therapeutics to the liver are not good enough for the majority of clinical applications. At the moment we often have to use these therapies in high doses to overcome their functional inefficiencies and achieve clinical benefit. 

“Up to now the gene therapy delivery tools have been tested in animal models, which while invaluable to evaluate safety and targeting of other organs/tissues, do not adequately replicate the functionality of these delivery methods in the patient.

“Together, this work broadens the repertoire of preclinical models available for conducting liver-directed vector studies and allows us to minimise the use of animals.

“Ideally this will bring us closer to more efficient gene therapies for diseases that currently have limited, if any, treatments.”

Associate Professor Lisowski said that this new advanced model of human liver will not only be a gamechanger when performing functional evaluation of novel therapeutics, but it will also allow to more accurately estimate the effective dose of new therapeutics and identify potential toxic side effects. 

It will also be a powerful system for developing novel fit-for-purpose viral vectors that will form the basis of next-generation advanced therapies.

The full study is accessible here.