Multidimensional pooled shRNA screens in human THP-1 cells identify candidate modulators of macrophage polarization

PLoS One. 2017 Aug 24;12(8):e0183679. doi: 10.1371/journal.pone.0183679. eCollection 2017.

Abstract

Macrophages are key cell types of the innate immune system regulating host defense, inflammation, tissue homeostasis and cancer. Within this functional spectrum diverse and often opposing phenotypes are displayed which are dictated by environmental clues and depend on highly plastic transcriptional programs. Among these the 'classical' (M1) and 'alternative' (M2) macrophage polarization phenotypes are the best characterized. Understanding macrophage polarization in humans may reveal novel therapeutic intervention possibilities for chronic inflammation, wound healing and cancer. Systematic loss of function screening in human primary macrophages is limited due to lack of robust gene delivery methods and limited sample availability. To overcome these hurdles we developed cell-autonomous assays using the THP-1 cell line allowing genetic screens for human macrophage phenotypes. We screened 648 chromatin and signaling regulators with a pooled shRNA library for M1 and M2 polarization modulators. Validation experiments confirmed the primary screening results and identified OGT (O-linked N-acetylglucosamine (GlcNAc) transferase) as a novel mediator of M2 polarization in human macrophages. Our approach offers a possible avenue to utilize comprehensive genetic tools to identify novel candidate genes regulating macrophage polarization in humans.

Publication types

  • Validation Study

MeSH terms

  • Cell Line, Tumor
  • Cell Polarity / genetics*
  • Humans
  • Macrophages / cytology*
  • Models, Biological
  • RNA, Small Interfering / genetics*
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • RNA, Small Interfering

Grants and funding

Novartis provided support in the form of salaries for authors ES, IC, FN, AT, CA, GH, JSRH, TP, RG, CGK, MGL, BB, MF, KS, TB and BDF, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.