Critical contribution of macrophage scavenger receptor 1 to the uptake of nanostructured DNA by immune cells

Nanomedicine. 2021 Jun:34:102386. doi: 10.1016/j.nano.2021.102386. Epub 2021 Mar 24.

Abstract

Despite the efficient uptake of polypod-like nanostructured DNA, or polypodna, by macrophage-like RAW264.7 and other immune cells, the detailed mechanism has not been fully elucidated. Our previous study using HEK-Blue hTLR9 cells showed that transfection of macrophage scavenger receptor 1 (MSR1) increased the uptake of tetrapod-like structured DNA. Here, we investigated the involvement of MSR1 in the structure-dependent uptake of polypodna. Transfection of MSR1 to HEK-Blue hTLR9 cells pod number-dependently increased the uptake of polypodna, and its knockout in RAW264.7 cells reduced the uptake and subsequent cytokine release. To examine the binding of DNA with MSR1, biotinylated DNA added to RAW264.7 cells was cross-linked with cell surface proteins. Then, MSR1 cross-linked with polypodna, but not with single-stranded DNA. Similar results were obtained with murine primary immune cells. Taken together, MSR1 discriminates between simple and nanostructured DNAs and plays a dominant role in the efficient uptake of polypodna by immune cells.

Keywords: CRISPR/Cas9; DNA nanostructure; DNA uptake; Pull-down assay; Scavenger receptor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CRISPR-Cas Systems
  • DNA / chemistry
  • DNA / metabolism*
  • Dextran Sulfate / pharmacology
  • Female
  • Gene Knockdown Techniques
  • HEK293 Cells
  • Humans
  • Macrophages / drug effects
  • Macrophages / metabolism*
  • Mice
  • Mice, Inbred BALB C
  • Nanostructures*
  • RAW 264.7 Cells
  • Scavenger Receptors, Class A / genetics
  • Scavenger Receptors, Class A / metabolism*
  • Transfection

Substances

  • Msr1 protein, mouse
  • Scavenger Receptors, Class A
  • DNA
  • Dextran Sulfate