Bio:

Courtney Vishy, MD, PhD is a Research Scientist at GenScript, where she works on mRNA and lipid nanoparticle (LNP)-based technologies for therapeutic development. She received her MD/PhD from the University of Washington, with a focus on translational and preclinical research. Her current work spans mRNA design, T cell biology, and LNP-mediated delivery, supporting the development and optimization of next-generation nucleic acid therapeutics. She is interested in advancing innovative platforms that bridge early research and clinical application.

Abstract:

Chimeric antigen receptor (CAR) T cell therapies have demonstrated transformative clinical success; however, current approaches relying on ex vivo engineering or viral vectors are limited by manufacturing complexity, cost, and safety concerns associated with genomic integration. mRNA-based CAR expression offers a transient, non-integrating alternative with improved safety and tunability, but achieving efficient in vivo delivery and sustained functional expression remains a key challenge.

Here, we present an integrated mRNA–lipid nanoparticle (LNP) platform for targeted, transient CAR expression in T cells. We developed a novel LNP formulation that enables enhanced and selective delivery of CAR mRNA to T cells without the need for antibody-mediated targeting, supporting a simplified and scalable strategy for in vivo cell engineering. CAR constructs targeting CD19 and BCMA were synthesized via in vitro transcription in both linear and circular RNA formats and evaluated in Jurkat and primary human T cells following LNP-mediated delivery. To optimize functional performance, we systematically evaluated modular CAR architectures, including variations in hinge and co-stimulatory domains, to understand their impact on CAR expression, tonic signaling, and T cell exhaustion. These studies identified key structural features that balance robust activation with controlled basal signaling, improving functional durability. Notably, circular RNA constructs demonstrated enhanced CAR expression and improved cytotoxic activity compared to linear mRNA. Together, this plug-and-play mRNA CAR platform enables tunable RNA design and delivery, advancing scalable, non-viral strategies for next-generation in vivo CAR-T therapies.

Abstract:

Antibody-oligonucleotide conjugates (AOCs) enable targeted gene silencing by combining antibody specificity with oligonucleotide therapeutics, increasing demand for robust scalable manufacturing. We developed site-specific cysteine conjugation strategies for antibody-siRNA across monoclonal, bispecific, and VHH formats. Optimized conditions favored DAR1, achieving ~75% conversion and >90% purity after ion exchange purification, with near-quantitative conversion for VHH conjugates. Analytical characterization (SDS-PAGE, CE-SDS, SEC, IEX, MS) confirmed product quality. DAR1 conjugates demonstrated improved in vitro knockdown and enhanced in vivo stability compared to higher DAR species.

These results establish a versatile conjugation platform and position DAR1 AOCs as a promising next-generation oligonucleotide therapeutic approach.