Replic-ON project – Pioneering the investigation of self-amplifying messenger RNA electroporation for long-lasting ex vivo transfection of immune cells.

Recently, there has been growing interest in the use of self-amplifying mRNA (saRNA) in therapeutic vaccines for infectious diseases and cancer. SaRNA is a type of messenger RNA (mRNA) that contains the non-structural proteins (nsP1-4) of an alphavirus replicase that copies the original strand of mRNA upon delivery into the cell. The nsP1-4 replicon is followed by a subgenomic promoter and the sequence of a gene of interest, allowing the expression of proteins of interest in the host cell. The self-replicating property means that proteins of interest encoded in the transfected saRNA will be expressed for a longer period of time compared to conventional mRNA. However, since there is no integration into the genome of the host cell, insertional mutagenesis is prevented. Thus, saRNA-based strategies combine the best of stable viral- or non-viral-based and transient mRNA-based engineering strategies. SaRNA is usually delivered in vivo as "naked" saRNA with or without intradermal electroporation or formulated into nanoparticle vaccines, with which expression of the protein of interest may last for 28 days. However, the exploitation of this technology for ex vivo modification of T cells in a therapeutic product has never been explored thus far. The primary objective of the Replic-ON project is to explore saRNA transfection as an innovative technology for genetically engineering immune cells in the context of the development of cell-based therapies. If successful, this project will provide groundbreaking data for the further development of ex vivo saRNA transfection technology as an amenable approach for T-cell genetic engineering in larger fundamental research project applications. We expect that this project will be the cornerstone for the much-needed development of more efficient and long-lasting non-integrating cellular immunotherapies while straddling the boundary between short-lived conventional mRNA technologies and integrating technologies such as viral transduction. Finally, this pioneering research would consolidate our leadership on ex vivo saRNA-based cellular therapies within the research community.

Keywords:T CYTOTOXIC LYMPHOCYTE, RNA, GENETIC ENGINEERING, IMMUNOTHERAPY

Disciplines:Hematology, Applied immunology, Cancer therapy