Targeted Delivery of CpG-Mir-146a Mimic Oligonucleotides As a Therapeutic Strategy to Reduce NF-Kb-Mediated Pathogenic Inflammation and Myeloid Leukemia Progression

NF-kB signaling plays central role in the regulation of immune cell activity. The microRNA-146a-5p (miR-146a) provides negative feedback inhibition of the NF-kB pathway to prevent either excessive immunity, such as cytokine release syndrome. Low expression of miR-146a is also implicated in certain types of leukemia, especially in del(5q)-syndrome myelodysplastic and acute myeloid leukemia (MDS/AML). While miR-146a is a potential therapeutic target, the lack of efficient miRNA delivery methods limits clinical translation. We previously developed a strategy for targeted delivery of oligonucleotide therapeutics, such as siRNA, into human and mouse myeloid cells and B cells, using partly or completely phophorothioated (PS) single-stranded oligodeoxynucleotides containing CpG motif (CpG ODN). Here, we demonstrate that similar strategy, using CpG ODN optimized for targeting human monocytes, can be employed for the delivery of functional miR-146a mimic. The CpG-miR146a mimic conjugate, but not unconjugated miR-146a, was quickly internalized by target human and mouse myeloid cells, such as dendritic cells, macrophages and leukemic cells. In vitro CpG-miR146a mimic reduced protein levels of downstream targets, Irak1 and Traf6, as well as the inhibition of DNA binding and transcriptional activity of NF-kB in myeloid cells. We further verified functional activity of CpG-miR146a mimic against several models of acute inflammation. The intravenous injections of this oligonucleotide reduced...
Source: Blood - Category: Hematology Authors: Tags: 802. Chemical Biology and Experimental Therapeutics: Poster II Source Type: research