Project description:The body-brain axis is emerging as a principal conductor of organismal physiology. It senses and controls organ function, metabolism and nutritional state. Here, we show that a peripheral immune insult powerfully activates the body-brain axis to regulate immune responses. We demonstrate that pro- and anti-inflammatory cytokines communicate with distinct populations of vagal neurons to inform the brain of an emerging inflammatory response. In turn, the brain tightly modulates the course of the peripheral immune response. Genetic silencing of this body-to-brain circuit produced unregulated and out-of-control inflammatory responses. By contrast, activating, rather than silencing, this circuit affords exceptional neural control of immune responses. We used single-cell RNA sequencing, combined with functional imaging, to identify the circuit components of this neuro-immune axis, and showed that its selective manipulation can effectively suppress the pro-inflammatory response while enhancing an anti-inflammatory state. The brain-evoked transformation of the course of an immune response offers new possibilities in the modulation of a wide range of immune disorders, from autoimmune diseases to cytokine storm and shock.
Project description:This SuperSeries is composed of the following subset Series: GSE36241: Identification of a FOXO3/IRF7 circuit that limits inflammatory sequelae of antiviral responses (ChIP-Seq) GSE37051: Identification of a FOXO3/IRF7 circuit that limits inflammatory sequelae of antiviral responses (expression) Refer to individual Series
Project description:Inflammation is characterized by a biphasic cycle consisting initially of a pro-inflammatory phase which is subsequently resolved by anti-inflammatory processes. The coordination of these two disparate states needs to be highly controlled, suggesting that the regulation of the cytokines that drive these processes are intimately linked. Interleukin-1 beta (IL1B) is a master regulator of pro-inflammation and is encoded within the same topologically associated domain (TAD) as interleukin-37 (IL37). IL37 has recently emerged as a powerful anti-inflammatory cytokine which diametrically opposes the function of IL1B. Within this TAD, we identified a novel long non-coding RNA called AMANZI which negatively regulates IL1B expression and trained immunity through the induction of IL37 transcription. We found that the activation of IL37 occurs through the formation of a dynamic long-range chromatin contact that leads to the temporal delay of anti-inflammatory responses. The common variant rs16944 present in AMANZI augments this regulatory circuit, predisposing individuals to enhanced pro-inflammation or immunosuppression. Our work illuminates a chromatin-mediated biphasic circuit coordinating expression of IL1B and IL37, thereby regulating two functionally opposed states of inflammation from within a single TAD.
Project description:Innate immune cells including myeloid cells exhibit dynamic cellular switches during inflammatory and immune responses against infection. These processes are tightly regulated at different levels including the cis-regulatory elements of immune cells. However, it remains unclear how the dynamic states of cis-regulatory elements of innate immune cells are controlled during inflammatory responses. Here we found that histone methylation regulator PTIP orchestrates inflammatory responses of macrophages through regulating acetylation state of enhancers and promoters. Rapid elevated expression of PTIP is observed in primary human and mouse macrophages upon lipopolysaccharide (LPS) stimulation. Loss of PTIP represses transcription of pro-inflammatory genes, and activates expression of anti-inflammatory genes. Mechanistically, we found that, independent of its function in histone methylation, PTIP interacts with acetyltransferase p300 and deacetylase HDACs, and serves as a beacon to recruit them to specific sites of inflammatory genes respectively. PTIP deficiency alters H3K27 acetylation state of cis-regulatory elements of inflammatory genes. Moreover, PTIP and c-JUN shape a positive and feedforward regulatory circuit. In addition, PTIP deletion sustains immunosuppressive function of tumor-associated macrophages (TAMs) and promotes tumor growth. Overall, our findings uncover a critical role of PTIP in altering the acetylation state of cis-regulatory regions and fine-tuning the inflammatory responses of innate immune cells.
2022-12-30 | GSE163463 | GEO
Project description:Identification of a FOXO3/IRF7 circuit that limits inflammatory sequelae of antiviral responses
Project description:Innate immune cells including myeloid cells exhibit dynamic cellular switches during inflammatory and immune responses against infection. These processes are tightly regulated at different levels including the cis-regulatory elements of immune cells. However, it remains unclear how the dynamic states of cis-regulatory elements of innate immune cells are controlled during inflammatory responses. Here we found that histone methylation regulator PTIP orchestrates inflammatory responses of macrophages through regulating acetylation state of enhancers and promoters. Rapid elevated expression of PTIP is observed in primary human and mouse macrophages upon lipopolysaccharide (LPS) stimulation. Loss of PTIP represses transcription of pro-inflammatory genes, and activates expression of anti-inflammatory genes. Mechanistically, we found that, independent of its function in histone methylation, PTIP interacts with acetyltransferase p300 and deacetylase HDACs, and serves as a beacon to recruit them to specific sites of inflammatory genes respectively. PTIP deficiency alters H3K27 acetylation state of cis-regulatory elements of inflammatory genes. Moreover, PTIP and c-JUN shape a positive and feedforward regulatory circuit. In addition, PTIP deletion sustains immunosuppressive function of tumor-associated macrophages (TAMs) and promotes tumor growth. Overall, our findings uncover a critical role of PTIP in altering the acetylation state of cis-regulatory regions and fine-tuning the inflammatory responses of innate immune cells.
Project description:Innate immune cells including myeloid cells exhibit dynamic cellular switches during inflammatory and immune responses against infection. These processes are tightly regulated at different levels including the cis-regulatory elements of immune cells. However, it remains unclear how the dynamic states of cis-regulatory elements of innate immune cells are controlled during inflammatory responses. Here we found that histone methylation regulator PTIP orchestrates inflammatory responses of macrophages through regulating acetylation state of enhancers and promoters. Rapid elevated expression of PTIP is observed in primary human and mouse macrophages upon lipopolysaccharide (LPS) stimulation. Loss of PTIP represses transcription of pro-inflammatory genes, and activates expression of anti-inflammatory genes. Mechanistically, we found that, independent of its function in histone methylation, PTIP interacts with acetyltransferase p300 and deacetylase HDACs, and serves as a beacon to recruit them to specific sites of inflammatory genes respectively. PTIP deficiency alters H3K27 acetylation state of cis-regulatory elements of inflammatory genes. Moreover, PTIP and c-JUN shape a positive and feedforward regulatory circuit. In addition, PTIP deletion sustains immunosuppressive function of tumor-associated macrophages (TAMs) and promotes tumor growth. Overall, our findings uncover a critical role of PTIP in altering the acetylation state of cis-regulatory regions and fine-tuning the inflammatory responses of innate immune cells.
Project description:Inflammation is characterized by a biphasic cycle consisting initially of a pro-inflammatory phase which is subsequently resolved by anti-inflammatory processes. The coordination of these two disparate states needs to be highly controlled, suggesting that the regulation of the cytokines that drive these processes are intimately linked. Interleukin-1 beta (IL1B) is a master regulator of pro-inflammation and is encoded within the same topologically associated domain (TAD) as interleukin-37 (IL37). IL37 has recently emerged as a powerful anti-inflammatory cytokine which diametrically opposes the function of IL1B. Within this TAD, we identified a novel long non-coding RNA called AMANZI which negatively regulates IL1B expression and trained immunity through the induction of IL37 transcription. We found that the activation of IL37 occurs through the formation of a dynamic long-range chromatin contact that leads to the temporal delay of anti-inflammatory responses. The common variant rs16944 present in AMANZI augments this regulatory circuit, predisposing individuals to enhanced pro-inflammation or immunosuppression. Our work illuminates a chromatin-mediated biphasic circuit coordinating expression of IL1B and IL37, thereby regulating two functionally opposed states of inflammation from within a single TAD.
Project description:Microglia/macrophages (Mi/MΦ) can profoundly influence stroke outcomes by acquiring functionally dominant phenotypes (pro-inflammatory or anti-inflammatory; neurotoxic or neuroprotective). Identification of the molecular mechanisms that dictate the functional status of Mi/MΦ after brain ischemia/reperfusion may reveal novel therapeutic targets for stroke. We hypothesized that activation of TGFβ-activated kinase 1 (TAK1), a key MAP3K upstream of multiple inflammation-regulating pathways, drives Mi/MΦ towards a pro-inflammatory phenotype and potentiates ischemia/reperfusion brain injury. Young adult mice were subjected to 1 h of middle cerebral artery occlusion (MCAO) followed by reperfusion. TAK1 was targeted by tamoxifen-induced Mi/MΦ-specific knockout (mKO). Mi/MΦ functional status and brain inflammatory profiles were assessed 3 days after MCAO by RNA-seq of flow cytometry-sorted brain Mi/MΦ. The results showed that TAK1 promotes ischemia/reperfusion-induced inflammation, brain injury, and maladaptive behavior by enhancing pro-inflammatory and neurotoxic Mi/MΦ responses.