Engineering Human Circulating Monocytes/Macrophages by Systemic Deliverable Gene Editing

Abstract

Delivery of plasmid DNA to transfect human primary macrophages is extremely difficult, especially for genetic engineering. Engineering macrophages is imperative for the treatment of many diseases including infectious diseases, cancer, neurological diseases, and aging. Unfortunately, plasmid does not cross the nuclear membranes of terminally differentiated macrophages to integrate the plasmid DNA (pDNA) into their genome. To address this issue, we have developed a core-shell nanoparticle (NP) using our newly created cationic lipid to deliver the anti-inflammatory cytokine IL-4 pDNA (IL-4pDNA-NPs). Human blood monocyte-derived macrophages (MDM) were effectively transfected with IL-4pDNA-NPs. IL-4pDNA-NPs were internalized in MDM within 30 minutes and delivered into the nucleus within 2 hours. Exogenous IL-4 expression was detected within 1 - 2 days and continued up to 30 days. Functional IL-4 expression led to M2 macrophage polarization in vitro and in an in vivo mouse model of inflammation. These data suggest that these NPs can protect pDNA from degradation by nucleases once inside the cell, and can transport pDNA into the nucleus to enhance gene delivery in macrophages in vitro and in vivo. In this research, we developed a new method to deliver plasmids into the nucleus of monocytes and macrophages for gene-editing. Introducing IL-4 pDNA into macrophages provides a new gene therapy solution for the treatment of various diseases.

Current Situation and Prospect of Adoptive Cellular Immunotherapy for Malignancies

“…109 Compared with immune cells such as T cells and NK cells, macrophages may infiltrate tumors in an immunosuppressive microenvironment more easily, providing more opportunities for tumor immunotherapy. 110 Unlike CAR-T cells, CAR-M cells have unique advantages. T cells cannot enter the tumor environment due to the physical barrier formed by the matrix surrounding tumor cells, whereas macrophages can visibly infiltrate the tumor environment.…”

“… 109 Compared with immune cells such as T cells and NK cells, macrophages may infiltrate tumors in an immunosuppressive microenvironment more easily, providing more opportunities for tumor immunotherapy. 110 …”