Surdziel et al. used the human monocytic THP-1 cell line for large-scale shRNA lentiviral library screening of the genes affecting human macrophage M1/M2 polarization, and identified known and novel regulators, including O-linked N-acetylglucosamine transferase, a mediator of M2 polarization and a suppressor of the M1 macrophage phenotype. These results were further validated by CRISPR knockout, small molecule inhibition, and transcriptional comparison of polarized human macrophage marker genes.
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.
Author Info: (1) Novartis Institutes for Biomedical Research, Basel, Switzerland. (2) Novartis Institutes for Biomedical Research, Basel, Switzerland. (3) Novartis Institutes for Biomedical Res
Author Info: (1) Novartis Institutes for Biomedical Research, Basel, Switzerland. (2) Novartis Institutes for Biomedical Research, Basel, Switzerland. (3) Novartis Institutes for Biomedical Research, Basel, Switzerland. (4) Novartis Institutes for Biomedical Research, Basel, Switzerland. (5) Novartis Institutes for Biomedical Research, Basel, Switzerland. (6) Novartis Institutes for Biomedical Research, Cambridge, United States of America. (7) Novartis Institutes for Biomedical Research, Cambridge, United States of America. (8) Novartis Institutes for Biomedical Research, Cambridge, United States of America. (9) Novartis Institutes for Biomedical Research, Basel, Switzerland. (10) Novartis Institutes for Biomedical Research, Basel, Switzerland. (11) Novartis Institutes for Biomedical Research, Basel, Switzerland. (12) Novartis Institutes for Biomedical Research, Basel, Switzerland. (13) Novartis Institutes for Biomedical Research, Basel, Switzerland. (14) Friedrich Miescher Institute for BioMedical Research, Basel, Switzerland. (15) Novartis Institutes for Biomedical Research, Basel, Switzerland. (16) Novartis Institutes for Biomedical Research, Basel, Switzerland. (17) Novartis Institutes for Biomedical Research, Basel, Switzerland.
