Uncoupling of IL-6 signaling and LC3-associated phagocytosis (LAP) drives immunoparalysis during sepsis
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PROVIDER: PRJNA728689 | ENA |
REPOSITORIES: ENA
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Project description:Immune deactivation of phagocytes is a central event in pathogenesis of sepsis that remains molecularly unexplored. In particular, how cytokine deregulation induced by sepsis compromises the microbicidal activity of phagocytes and results in secondary infections by opportunistic bacterial and fungal pathogens is incompletely understood. Herein, we identify a master regulatory role of cytokine signaling on LC3-associated phagocytosis (LAP), and reveal that uncoupling of these two processes during sepsis induces immunoparalysis in monocytes/macrophages.
2022-05-01 | GSE174183 | GEO
Project description:Targeting autophagy in cancer cells and in the tumor microenvironment are current goals of cancer therapy. However, components of canonical autophagy play roles in other biological processes, adding complexity to this goal. One such alternative function of autophagy proteins is LC3-associated phagocytosis (LAP), which functions in phagosome maturation and subsequent signaling events. Here we show that impairment of LAP in the myeloid compartment, rather than canonical autophagy, induces control of tumor growth by tumor-associated macrophages (TAM) upon phagocytosis of dying tumor cells. Single cell RNAseq analysis revealed that defects in LAP induce pro-inflammatory gene expression and trigger STING-mediated type I interferon responses in TAM. We found that the anti-tumor effects of LAP impairment require tumor-infiltrating T cells, dependent upon the STING and the type I interferon response. Therefore, autophagy proteins in the myeloid cells of the tumor microenvironment contribute to immune suppression of T lymphocytes by effecting LAP.
2018-09-15 | GSE118019 | GEO
Project description:Mycobacterium tuberculosis’success as a pathogen comes from itsability to evade degradation by macrophages. Normally macro-phages clear microorganisms that activate pathogen-recognitionreceptors (PRRs) through a lysosomal-trafficking pathway called“LC3-associated phagocytosis”(LAP). AlthoughM.tuberculosisac-tivates numerous PRRs, for reasons that are poorly understoodLAP does not substantially contribute toM.tuberculosiscontrol.LAP depends upon reactive oxygen species (ROS) generated byNADPH oxidase, butM.tuberculosisfails to generate a robustoxidative response. Here, we show that CpsA, a LytR-CpsA-Psr(LCP) domain-containing protein, is required forM.tuberculosisto evade killing by NADPH oxidase and LAP. Unlike phagosomescontaining wild-type bacilli, phagosomes containing theΔcpsAmutant recruited NADPH oxidase, produced ROS, associated withLC3, and matured into antibacterial lysosomes. Moreover, CpsAwas sufficient to impair NADPH oxidase recruitment to fungal par-ticles that are normally cleared by LAP. Intracellular survival of theΔcpsAmutant was largely restored in macrophages missing LAPcomponents (Nox2,Rubicon,Beclin,Atg5,Atg7,orAtg16L1) butnot in macrophages defective in a related, canonical autophagypathway (Atg14,Ulk1,orcGAS). TheΔcpsAmutant was highlyimpaired in vivo, and its growth was partially restored in micedeficient in NADPH oxidase,Atg5,orAtg7, demonstrating thatCpsA makes a significant contribution to the resistance ofM.tu-berculosisto NADPH oxidase and LC3 trafficking in vivo. Overall,our findings reveal an essential role of CpsA in innate immuneevasion and suggest that LCP proteins have functions beyond theirpreviously known role in cell-wall metabolism.
2019-12-13 | GSE141931 | GEO
Project description:Necrosis is commonly found in various solid tumors and predicts worse outcome. Chronic ischemia can initiate tumor necrosis, but how the damaged tissue further expands is unclear. Previous studies found that neutrophils associate with necrosis and could contribute to necrosis development in glioblastoma (GBM) by transferring myeloperoxidase (MPO)-containing granules into tumor cells and inducing tumor cell ferroptosis. How the neutrophilic granule transfer occurs is unknown. Here, through an unbiased small molecule screen, we found that statins can inhibit neutrophil-induced tumor cell death by blocking the neutrophilic content transfer into tumor cells. Surprisingly, we found that neutrophils are engulfed by tumor cells before they are fragmented and release the MPO-containing contents in tumor cells. This process involves LC3-associated phagocytosis (LAP) and can be blocked by inhibiting the Vps34-UVRAG-containing PI3K complex. Inhibition of MPO or depletion of Vps34 in an orthotopic xenograft GBM mouse model reduced necrosis formation and allowed tumor-bearing mice to survive longer. Therefore, this study revealed that the neutrophilic granule transfer involves LAP-mediated neutrophil internalization, which then triggers tumor ferroptotic cell death in glioblastoma. Blocking this process may improve prognosis of GBM.
2024-04-29 | GSE263766 | GEO
Project description:Phagocytic clearance of apoptotic germ cells by Sertoli cells is vital for germ cell development and differentiation. Using a tissue-specific miRNA transgenic mouse model, we show that interaction between miR-471-5p and autophagy member proteins regulates clearance of apoptotic germ cells via LC3-associated phagocytosis (LAP).
2017-11-01 | GSE99500 | GEO
Project description:Regulation of myeloid function by LC3-associated phagocytosis promotes tumor immune tolerance
| PRJNA484019 | ENA
Project description:Mycobacterium tuberculosis is protected from NADPH oxidase and LC3-associated phagocytosis by the LCP protein CpsA
| PRJNA595319 | ENA
Project description:Blood monocytes serve as the first line of host defense and are equipped to recognize and respond to infection by triggering an immune-inflammatory response. While most information on these cells comes from in vitro studies in humans or in vivo studies in mice, little is known about monocytes under human disease conditions. We investigated the role of monocytes during sepsis and its resolution in humans. A transcriptomal and functional analysis of blood monocytes from patients during gram negative sepsis and at recovery was performed. Monocytes from sepsis patients showed upregulation of a large number of pro-inflammatory genes and cytokines/chemokines, consistent with an ongoing systemic inflammation. However, these cells showed impairment to ex vivo endotoxin (LPS) challenge, displaying a quantitative decrease in the number of LPS-inducible genes. Moreover, they downregulated the expression of several pro-inflammatory cytokine/chemokine genes, activation marker genes and transcription factors associated with monocyte/macrophage activation, upon ex vivo LPS stimulation. Functionally, they downregulated expression of inflammatory cytokines/chemokines and antigen presentation-related molecules and functions. In contrast, genes and functions related to phagocytosis, anti-microbial activity and tissue remodeling where remained unaffected or even enhanced . Collectively, our observations suggest a genetic and functional re-programming of these cells during human sepsis progression. Understanding the molecular mechanisms which regulate this re-programming will allow to devise strategies which could modulate the response of these cells and hence, disease progression. Blood monocytes from gram-negative sepsis patients during sepsis (Sepsis) and following their recovery (Recovery/Basal) as well as healthy donor (control) were isolated. Thereafter, these cells were treated ex vivo with or without LPS for 3h and analysed for transcriptomic study.
2014-05-14 | E-GEOD-46955 | biostudies-arrayexpress
Project description:As the professional phagocyte in the central nervous system (CNS), microglia are the primary scavenger removing cell corpses. The failure of microglia in debris clearance influences the normal CNS function. Meanwhile, microglia undergo turnover during the whole lifespan. If dead microglia are not timely removed, accumulated corpses may influence the CNS function. The microglial corpse clearance is hereby crucial for CNS homeostasis. However, the underlying mechanism remains obscure. In this study, we investigated how microglial corpses are removed. We found that microglial corpses are mainly phagocytosed by astrocytes, mediated by C4b opsonization. Then engulfed microglial fragments are degraded in astrocytes via the RUBICON-dependent LC3-associated phagocytosis (LAP), a form of non-canonical autophagy. The interference of the C4b-mediated engulfment and its subsequent LAP disrupt the microglial debris removal and degradation, respectively. Together, we elucidated cellular and molecular mechanisms of microglial debris removal, extending the knowledge on how the CNS homeostasis is maintained.
2022-09-01 | GSE171321 | GEO
Project description: Not available
| S-EPMC6432721 | biostudies-literature