STAG2 deficiency induces interferon responses via cGAS-STING pathway and restricts virus infection

Abstract

Cohesin is a multi-subunit nuclear protein complex that coordinates sister chromatid separation during cell division. Highly frequent somatic mutations in genes encoding core cohesin subunits have been reported in multiple cancer types. Here, using a genome-wide CRISPR-Cas9 screening approach to identify host dependency factors and novel innate immune regulators of rotavirus (RV) infection, we demonstrate that the loss of STAG2, an important component of the cohesin complex, confers resistance to RV replication in cell culture and human intestinal enteroids. Mechanistically, STAG2 deficiency results in spontaneous genomic DNA damage and robust interferon (IFN) expression via the cGAS-STING cytosolic DNA-sensing pathway. The resultant activation of JAK-STAT signaling and IFN-stimulated gene (ISG) expression broadly protects against virus infections, including RVs. Our work highlights a previously undocumented role of the cohesin complex in regulating IFN homeostasis and identifies new therapeutic avenues for manipulating the innate immunity.

TMPRSS2 and TMPRSS4 mediate SARS-CoV-2 infection of human small intestinal enterocytes

“…Human rotavirus WI61 strain was propagated as described before ( 48 ). VSV-SARS-CoV-2-S-GFP and VSV-SARS-CoV-S-GFP were propagated in MA104 cells in T175 flasks and virus sequences can be found in Table S1.…”

“…For brightfield and epifluorescence, cultured cells or human enteroids were cultured in 24-well plates and images were taken by REVOLVE4 microscope (ECHO) with a 10X objective. For confocal microscopy, enteroids were seeded into 8-well Nunc chamber slides (Thermo Fisher), cultured under maintenance or differentiation conditioned, infected with SARS-CoV-2 chimera virus, and fixed with 4% paraformaldehyde as previously described ( 48 ). Samples were then stained with the following primary antibodies or fluorescent dyes: ACE2 (sc-390851 AF594, Santa Cruz), DAPI (P36962, Thermo Fisher), SARS-CoV-2 S (CR3022 human monoclonal antibody ( 51 )), Villin (sc-58897 AF488, Santa Cruz), and phalloidin (Alexa 647-conjugated, Thermo Fisher).…”

TMPRSS2 and TMPRSS4 promote SARS-CoV-2 infection of human small intestinal enterocytes

“…Plaque assays were performed in MA104 cells seeded in six-well plates using an adapted version of the rotavirus plaque assay protocol (23). Human rotavirus WI61 strain was propagated as described before (55). TCID 50 (median tissue culture infectious dose and FFU (focus-forming unit) assays were performed in MA104 cells seeded in flat-bottom 96-well plates using serial dilutions.…”

“…Colocalization signals were quantified by ImageJ plugins and geotests.net. For confocal microscopy, enteroids were seeded into eight-well Nunc chamber slides (Thermo Fisher Scientific), cultured under maintenance or differentiation conditions, infected with VSV-SARS-CoV-2, and fixed with 4% paraformaldehyde as previously described (55). Samples were then stained with the following primary antibodies or fluorescent dyes: ACE2 (sc-390851 AF594, Santa Cruz Biotechnology), 4′,…”

Regulation of cGAS‐Mediated Immune Responses and Immunotherapy

“…Ding et al used a genome‐wide clustered regularly interspaced short palindromic repeats CRISPR‐associated protein 9 (CRISPR‐Cas9) method to demonstrate the decline of stromal antigen 2 (STAG2), a constituent of the nuclear cohesin complex. Systematically, STAG2 deficiency triggered spontaneous genomic DNA damage, active IFN‐stimulated gene (ISG) expression, and Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling via stimulation of the cGAS‐STING signaling pathway, which protected against viral infections, including rotaviruses (RVs) 75…”