Project description:We show that Manganese (II) is a potent type I-IFN inducing agonist, stimulating cells into an anti-viral state in the absence of infection. Mechanically, Mn2+ treatment led to a profound cGAS-STING-dependent innate immune activation, conferring cells or mice viral resistance.
Project description:Epigenetic mechanism contributes to immune landscapes in cancer. Here we identify the SETDB1-TRIM28 complex as a critical suppressor of antitumor immunity. An epigenetic CRISPR-Cas9 screen of 1,218 chromatin regulators identified TRIM28 as a novel suppressor of PD-L1 expression. We revealed that expression of the SETDB1-TRIM28 complex negatively correlates with infiltration of effector CD8+ T cells. Inhibition of SETDB1-TRIM28 simultaneously upregulates PD-L1 and activates the cGAS-STING innate immune response to increase infiltration of CD8+ T cells. Mechanistically, SETDB1-TRIM28 inhibition leads to micronuclei formation in cytoplasm, a known activator of the cGAS-STING pathway. Thus, SETDB1-TRIM28 inhibition bridges the innate and adaptive immunity. Indeed, SETDB1 knockout enhances the antitumor effects of immune checkpoint blockade anti-PD-L1 in an ovarian cancer mouse model in a cGAS dependent manner. Our findings establish SETDB1-TRIM28 complex as a regulator of antitumor immunity and its loss activates cGAS-STING innate immunity to boost antitumor effects of immune checkpoint blockades.
Project description:Epigenetic mechanism contributes to immune landscapes in cancer. Here we identify the SETDB1-TRIM28 complex as a critical suppressor of antitumor immunity. An epigenetic CRISPR-Cas9 screen of 1,218 chromatin regulators identified TRIM28 as a novel suppressor of PD-L1 expression. We revealed that expression of the SETDB1-TRIM28 complex negatively correlates with infiltration of effector CD8+ T cells. Inhibition of SETDB1-TRIM28 simultaneously upregulates PD-L1 and activates the cGAS-STING innate immune response to increase infiltration of CD8+ T cells. Mechanistically, SETDB1-TRIM28 inhibition leads to micronuclei formation in cytoplasm, a known activator of the cGAS-STING pathway. Thus, SETDB1-TRIM28 inhibition bridges the innate and adaptive immunity. Indeed, SETDB1 knockout enhances the antitumor effects of immune checkpoint blockade anti-PD-L1 in an ovarian cancer mouse model in a cGAS dependent manner. Our findings establish SETDB1-TRIM28 complex as a regulator of antitumor immunity and its loss activates cGAS-STING innate immunity to boost antitumor effects of immune checkpoint blockades.
Project description:The cGAS-STING pathway, a central component of the innate immune system, senses cytosolic DNA and induces interferon-stimulated genes (ISGs) to mediate inflammation. Here we report the unexpected discovery that cGAS senses dysfunctional protein production. Purified ribosomes interact with and stimulate the catalytic activity of recombinant cGAS in vitro. Disruption of the ribosome-associated protein quality control pathway, which detects and resolves ribosome collisions, results in cGAS- and STING-dependent ISG expression, and causes the re-localization of cGAS from the nucleus to the cytosol. Indeed, cGAS preferentially binds collided ribosomes in vitro, and other orthogonal perturbations that lead to elevated levels of collided ribosomes cause re-localization of cGAS as well. Thus, the cGAS-STING pathway senses and responds to translation stress. These findings have implications for the inflammatory responses to viral infection and tumorigenesis, both of which substantially reprogram cellular protein synthesis.
Project description:The cGAS-STING signalling has been well recognized as the major pathway response to self and non-self DNA molecule in cytoplasm. Here, we measured the temporal transcriptome dynamic changes after cGAS-STING signalling activation based on cGAS specific agonist G3-YSD transfection
Project description:The cGAS-STING pathway, a central component of the innate immune system, senses cytosolic DNA and induces interferon-stimulated genes (ISGs) to mediate inflammation. Here we report the unexpected discovery that cGAS senses dysfunctional translation. Purified ribosomes interact with and stimulate recombinant cGAS catalytic activity in vitro. Disruption of the ribosome-associated protein quality control pathway, which detects and resolves ribosome collisions, results in cGAS- and STING-dependent ISG expression, and cause the re-localization of cGAS from the nucleus to the cytosol. Other orthogonal perturbations that lead to elevated levels of collided ribosomes cause re-localization of cGAS as well. Thus, the cGAS-STING pathway senses and responds to translation stress. These findings have implications for the inflammatory responses to viral infection and tumorigenesis, both of which substantially reprogram cellular protein synthesis.
Project description:Patients with anti-MPO vasculitis have increased serum levels of the signalling molecule cGAMP suggestive of ongoing DNA recognition by the cGAS/STING pathway. Consistent with this gene set enrichment analysis of peripheral blood mononuclear cell transcriptomes from patients with active anti-MPO vasculitis revealed up-regulation of type 1 interferon response genes compared to healthy controls.
Project description:The DNA exonuclease TREX1 degrades endogenous cytosolic DNA. Cytosolic DNA triggers the cGAS/STING pathway which increases type I interferon. To investigate the physiological significance of TREX1 loss on in vivo tumor growth, we implanted control and TREX1-deficient CT26 tumor cells into immunocompetent BALB/c hosts.Tumor cells were collected 7 days after tumors reached around 200mm3.
Project description:The cytosolic DNA sensor cyclic GMP-AMP (cGAMP) synthetase (cGAS) has emerged as a fundamental component fueling the anti-pathogen immunity. Because of its pivotal role in initiating innate immune response, the activity of cGAS must be tightly fine-tuned to maintain immune homeostasis in antiviral response. Here, we reported that neddylation modification was indispensable for appropriate cGAS-STING signaling activation. Blocking neddylation pathway using neddylation inhibitor MLN4924 substantially impaired the induction of type I interferon and proinflammatory cytokines, which was selectively dependent on Nedd8 E2 enzyme Ube2m. We further found that deficiency of the Nedd8 E3 ligase Rnf111 greatly attenuated DNA-triggered cGAS activation while not affecting cGAMP induced activation of STING, demonstrating that Rnf111 was the Nedd8 E3 ligase of cGAS. We further identified Lys231 and Lys421 as the key neddylation sites in human cGAS. Mechanistically, Rnf111 interacted with and polyneddylated cGAS, which in turn promoted its dimerization and enhanced the DNA-binding ability, leading to proper cGAS-STING pathway activation. In the same line, the Ube2m or Rnf111 deficiency mice exhibited severe defects in innate immune response and were susceptible to HSV-1 infection. Collectively, our study uncovered a vital role of the Ube2m-Rnf111 neddylation axis in promoting the activity of the cGAS-STING pathway and highlighted the importance of neddylation modification in antiviral defense.
Project description:Transcriptional analysis of 6-month-old primary nucleus pulposus (NP) and annulus fibrosus (AF) mouse disc tissues from wild-type (WT) and N153S mice, which harbor a mutation wich constiuitively activates Sting. Mouse details available here: https://www.jax.org/strain/033543 The cGAS-STING pathway promotes the senescence-associated secretory phenotype (SASP), which is associated with intervertebral disc degeneration, and has had implications in inflammatory musculoskeletal disorders. We examined the role of STING in the disc by examining the transcriptomic profiles of nucleus pulposus and annulus fibrosus cells in WT and N153S mice using microarray.