In vivo delivery of a fluorogenic antisense oligonucleotide into human leukocytes in a humanized mouse model system
Oligonucleotides have become essential tools in basic biomedical research and are currently used in a multitude of applications; however, their potential for highly specific oligonucleotide-based therapeutics has been limited by the lack of effective delivery vehicles.
Nathan B. Seidel,1Saurav S. Rout,1Beverly Z. Packard,2,3and Kerry J. Lavender1,3
1Department of Biochemistry, Microbiology and Immunology, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada; 2OncoImmunin, Inc.,
Gaithersburg, MD 20877, USA
Development of oligonucleotide-based therapeutics has been limited by the lack of effective in vivo delivery vehicles. We previously showed that the presence of an H-type excitonic dimer formed by the covalent binding of two fluorophores with significant transition dipoles on opposite ends of peptide or nucleic acid sequences of interest facilitated their delivery into live cells in vitro. Here, we evaluated delivery of a fluoro-genic anti-sense oligonucleotide (ASO) complementary to β-actin (ACTB) mRNA into human leukocytes in vivo using a humanized mouse model. We observed delivery of the ASO into human leukocytes at a median of ≥94% in blood, spleen, bone marrow, and liver with half-lives of at least 72 h. Additionally, we detected the ASO in a significant proportion of human leukocytes within difficult-to-penetrate tissues such as brain and gut. The ASO localized to the perinuclear space within target cells and mediated reductions in bone marrow ACTB transcripts after a single intravenous injection. The delivery system described herein is a technology platform with the capacity for highly efficient systemic delivery of therapeutic oligonucleotides that will facilitate development of a new class of drugs for treatment of HIV and other pathologic conditions.
