An effective cell-penetrating antibody delivery platform

Area of Science:

• Biotechnology
• Molecular Biology
• Immunology

Background:

• Antibodies are crucial therapeutics but struggle to reach intracellular targets.
• Many diseases stem from intracellular molecules inaccessible to antibodies.
• Developing methods for intracellular antibody delivery is a significant challenge.

Purpose of the Study:

• To develop a method for enabling antibodies to penetrate cellular membranes.
• To demonstrate the efficacy of modified antibodies in targeting and modulating intracellular molecules.
• To establish a new platform for antibody-based intracellular research and therapeutics.

Main Methods:

• Covalent conjugation of phosphorothioated DNA oligonucleotides to antibodies.
• Assessment of antibody cellular internalization and membrane potential alteration.
• Evaluation of intracellular antibody clearance mechanisms (efflux, lysosomal degradation).
• In vitro testing in fibroblasts, tumor cells, and T cells.
• In vivo studies involving local and systemic administration in tumor models.

Main Results:

• Modified antibodies efficiently internalized into cells.
• Cellular uptake was partly mediated by membrane potential changes.
• Target-dependent retention of antibodies within cells was observed.
• Inhibition of intracellular targets (Myc, IRF4, SRC) and downstream gene expression.
• Demonstrated tumor cell apoptosis and growth inhibition in vivo.
• Successful detection and modulation of intracellular targets in various cell types and animal models.

Conclusions:

• Antibody-DNA oligonucleotide conjugation is a simple yet effective strategy for intracellular delivery.
• This approach overcomes the limitation of antibody impermeability to cell membranes.
• Enables antibody-based targeting of intracellular molecules for research, diagnostics, and therapeutics.
• Paves the way for a new era of intracellular antibody applications.