Highly efficient CD4+ T cell targeting and genetic recombination using engineered CD4+ cell-homing mRNA-LNPs

Area of Science:

• Biotechnology
• Immunology
• Molecular Medicine

Background:

• Nucleoside-modified messenger RNA (mRNA) in lipid nanoparticles (LNPs) are key components of COVID-19 vaccines.
• mRNA therapeutics offer potential for modulating immune cells like T lymphocytes for various conditions.
• T cells present a significant challenge for exogenous mRNA transfection.

Purpose of the Study:

• To develop a method for specific targeting and mRNA delivery to CD4+ T cells.
• To establish a platform technology for mRNA-based immunotherapy and potential HIV cure.

Main Methods:

• Conjugation of CD4 antibody to LNPs for targeted delivery.
• Systemic injection of CD4-targeted, radiolabeled mRNA-LNPs in mice.
• Administration of CD4-targeted LNPs with Cre recombinase-encoding mRNA.
• T cell phenotyping to assess transfection uniformity.

Main Results:

• CD4-targeted mRNA-LNPs showed significantly higher accumulation in spleen T cells compared to non-targeted LNPs (approx. 30-fold increase).
• Specific, dose-dependent genetic recombination and reporter gene expression observed in CD4+ T cells in spleen (approx. 60%) and lymph nodes (approx. 40%).
• Uniform transfection across naive, central memory, and effector T cell subpopulations was confirmed.

Conclusions:

• CD4 antibody conjugation to LNPs enables efficient and specific mRNA targeting and transfection of T cells.
• This technology provides a promising platform for T cell-based immunotherapies and potential treatments for conditions like HIV.