The Emerging Role of In Vitro-Transcribed mRNA in Adoptive T Cell Immunotherapy

Abstract

Adoptive T cell therapy is a form of cellular therapy that utilizes human immune cells, often empowered by the expression of recombinant proteins, to attack selected targets present on tumor or infected cells. T cell-based immunotherapy has been progressing over the past several decades, and reached a milestone with the recent US Food and Drug Administration (FDA) approval of chimeric antigen receptor T cell therapy for relapsed and refractory leukemia and lymphoma. Although most studies have used viral vectors, a growing number of researchers have come to appreciate in vitro-transcribed (IVT) mRNA for the development, testing, and application of T cell-based immunotherapeutics. IVT mRNA offers inherent safety features, highly efficient recombinant protein translation, and the ability to control pharmacokinetic properties of the therapy. In this review, we discuss the history of IVT mRNA in adoptive T cell therapy, from tumor-infiltrating lymphocytes and T cell receptor-based therapies to chimeric antigen receptor therapy and gene-editing techniques, as well as prior and ongoing clinical trials. In 2006, Rabinovich et al. 11 were the first to transduce T cells with IVT mRNA encoding chimeric antigen receptors (CARs) directed against CD19 and demonstrated functionality of those T cells in vitro. By 2009, several studies reported using IVT mRNA to create

Intracellular Delivery of mRNA in Adherent and Suspension Cells by Vapor Nanobubble Photoporation

“…Indeed, transduction efficiencies typically range from a few percentages to over 80% in reported clinical trials [58][59][60]. As a consequence, mRNA-based cell therapies have come up as a safer and cheaper alternative to viral transductions [2]. In this work, we report for the first time on the use of VNB photoporation as a promising physical technique for gentle but efficient mRNA transfections.…”

“…In recent years, mRNA has gained immense interest as a novel class of nucleic acid therapeutics [1][2][3]. In contrast to DNA therapeutics, mRNA does not require nuclear entry to be functional, being translated instantly after reaching the cell cytoplasm and thus avoiding potential insertional mutagenesis.…”

“…Physical delivery methods have recently gained attention when it comes to in vitro and ex vivo cell modification, featuring a broad applicability on different cell types and cargos [17,25]. Electroporation, which makes use of strong electric fields to deliver nucleic acids to the cell interior, is currently the preeminent tool for mRNA transfections of hard-to-transfect immune cells [2,26]. It should be noted, however, that electroporation was amply shown to come with significant loss of cell viability, induction of unwanted phenotypic changes or loss of cell functionality [17,[27][28][29][30].…”

Targeted Cellular Micropharmacies: Cells Engineered for Localized Drug Delivery

“…This method allows for larger transgene constructs but is less efficient than viral transduction and causes significant cellular toxicities [95]. mRNA-mediated transgene delivery similarly allows for larger gene cassettes, but since expression is driven by the translation of exogenously delivered mRNA, the transgene is rapidly diluted and degraded as cells divide [96].…”

Nanomedicines to Deliver mRNA: State of the Art and Future Perspectives

“…Ravinovich et al [195] transfected for the first time T cells with IVT mRNA encoding CARs against CD19. Transient expression of T cells transduced by IVT mRNA offers safety features and highly efficient recombinant protein translation, but also results in the need for frequent injections of the CAR T cells [196]. Currently, several clinical trials with IVT mRNA CAR T cells for cancer treatment are ongoing.…”