Stable Gene Transfer by RNA Delivery - Abstract
Non-viral gene delivery is used in most biomedical laboratories for basic research and for many commercial
and medical applications. These include basic investigations into gene function, modification of cells for the
production of recombinant proteins, and generation of genetically modified human cells for cancer therapy (e.g.
chimeric antigen receptor transgenic T cells). However, the delivery of DNA by transfection for gene transfer is
limited by its extremely high toxicity to many cell types, such as hematopoietic stem cells and other blood cell
types (e.g. human T cells). Thus, gene delivery by DNA transfection is very inefficient except in a subset of cell
lines selected for transfectability (e.g. HEK293T cells). In contrast, delivery of in vitro transcribed mRNA results
in robust gene expression in a very high percentage of cells without toxicity, greatly out-performing DNA
delivery. Unfortunately, the transient nature of an mRNA limits the utility of this gene delivery method to
special, rare circumstances where a short duration of expression is acceptable. But in most gene therapy
settings, and in many experiments, permanent gene expression is desired. In this proposal from B-MoGen
Biotechnologies, Inc., we will establish the feasibiliy our entirely new gene delivery system in which an RNA
molecule is delivered to cells, that is then converted to a DNA copy in the cell, where it is efficiently integrated
into the genome and expressed. This novel system should combine the efficiency and non-toxicity of RNA
gene delivery with the permanence of DNA gene delivery. The applications of this technology for research are
many, including numerous settings where DNA transfection is sub-optimal. Moreover, this technology could
revolutionize therapeutic gene delivery to human cells including correction of genetic diseases in blood stem
cells, delivery of chimeric antigen receptor transgenes to T cells, and delivery of substrate DNA molecules for
homology dependent repair after targeted nuclease-mediated double-stranded DNA cutting. The technology is
based on a retrotransposon from mice, called the Intracisternal Type A Particle (IAP), which does not exist in
human cells. As such, it is an ideal RNA-based permanent gene delivery vehicle for human cells and could be
applied to tissues in situ.