Selective targeting of cytotoxic effector CD8+ T cells via CX3CL1-conjugated mRNA lipid nanoparticles

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Presentation Time: 11:30 AM - 12:45 PM
Poster Board Number: B833
Abstract ID: 6007

Presenting Author:
Angela R Corrigan , PhD Candidate at Univ. of Pennsylvania Perelman Sch. of Med.

Abstract:

Targeted delivery of mRNA lipid nanoparticles (LNPs) to cytotoxic effector CD8+ T cells (T_eff) holds potential promise as a therapeutic tool for chronic infection, cancer, and autoimmunity. However, current LNP targeting strategies such as lipid modification or antibody conjugation do not yet provide sufficient T cell subset specificity to mitigate off-target effects. Here, we hypothesized that the interaction between CX3CR1, a chemokine receptor highly expressed on T_eff cells and its natural ligand CX3CL1 could be exploited for the selective uptake of mRNA LNPs by T_eff cells and subsequent reprogramming via expression of encoded protein. As a proof-of-concept, we found that CX3CL1-conjugated GFP-encoding mRNA LNPs readily (<16 hours) and selectively target primary human T_eff cells in a dose dependent manner ex vivo, with minimal uptake by naïve or central memory CD8+ T cells. The cytotoxicity of the T_eff cells was maintained after LNP uptake with no loss of perforin or granzyme B expression in GFP+ T_eff cells. Furthermore, this targeting approach was efficacious in vivo, with ~60% of murine CX3CR1+ T_eff cells expressing GFP 24 hours after intravenous administration of murine fractalkine-conjugated GFP mRNA LNPs. Collectively, these data show that CX3CL1-conjugation and, more broadly, natural ligand-conjugation of mRNA LNPs, is an effective and efficient method for targeted delivery of mRNA, enabling selective reprogramming of lymphocyte subsets ex vivo or in vivo.