Assessment of pre-clinical liver models based on their ability to predict the liver-tropism of AAV vectors

Abstract

The liver is a prime target for in vivo gene therapies using recombinant adeno-associated viral vectors (rAAV). Multiple clinical trials have been undertaken for this target in the past 15 years, however we are still to see market approval of the first liver-targeted AAV-based gene therapy. Inefficient expression of the therapeutic transgene, vector-induced liver toxicity and capsid, and/or transgene-mediated immune responses reported at high vector doses are the main challenges to date. One of the contributing factors to the insufficient clinical outcomes, despite highly encouraging preclinical data, is the lack of robust, biologically- and clinically-predictive preclinical models. To this end, this study reports findings of a functional evaluation of six AAV vectors in twelve preclinical models of the human liver, with the aim to uncover which model is the most relevant for the selection of AAV capsid variant for safe and efficient transgene delivery to primary human hepatocytes. The results, generated by studies in models ranging from immortalized cells, iPSC-derived and primary hepatocytes, and primary human hepatic organoids to in vivo models, increased our understanding of the strengths and weaknesses of each system. This should allow the development of novel gene therapies targeting the human liver.

Progress in developing microphysiological systems for biological product assessment

“…In conclusion, the study demonstrated that while AAV5 displayed greater transduction efficiency in hLTEs than AAV3b, both groups exhibited compromised selfaggregation and diminished hepatocyte functionality, warranting further attention and investigation. Similarly, Westhaus and colleagues 70 conducted a functional evaluation of six AAV vectors in twelve in vitro models of the human liver including immortalized cells, iPSC-derived and primary hepatocytes, as well as primary human hepatic organoids, and in vivo models Fig. 2b.…”

“…52 B) Safety assessment: The safety of six AAV variants in preclinical models of the human liver was studied to uncover which combination of models is the most relevant for the identification of AAV capsid variant for safe and efficient transgene delivery to primary human hepatocytes. 70 C) Immune response: MPS that supports a triple culture of threedimensional (3D) colorectal tumor microtissues, 3D cardiac microtissues, and human-derived natural killer (NK) cells in the same microfluidic network to study the possible interactions among components. 71 leukocyte antigen (HLA) mediation for specific targeting of tumor cells.…”