Similar Datasets
Project description:Tissue-resident macrophages have an embryonic origin, but are replenished under steady state conditions in some tissues by blood monocytes that can adopt genotypic and phenotypic features of the residents. However, little is known about the residency and functional properties of infiltrating macrophages after an inflammatory challenge. The meninges of the central nervous system (CNS) are populated by a dense network of specialized macrophages that act as resident immune sentinels. Here we show that following lymphocytic choriomeningitis virus infection resident meningeal macrophages become activated by innate inflammatory cytokines, acquire viral antigen, and interact directly with infiltrating cytotoxic T lymphocytes (CTL), which leads to their depletion. Concurrently, the meninges are heavily infiltrated by peripherally-derived inflammatory monocytes that engraft the meningeal niche and remain in situ for months after viral clearance. This engraftment leads to phenotypic and functional changes in the pool of resident meningeal macrophages that depends in part on IFNγ signaling. These changes include loss of bacterial and immunoregulatory sensors that impede subsequent CNS immune reactions. Collectively, these data indicate that peripheral monocytes can engraft the meninges after an inflammatory challenge, imprinting the compartment with long-term defects in immune function.
2019-03-06 | GSE108467 | GEO
Project description:Tissue-resident macrophages have an embryonic origin, but are replenished under steady state conditions in some tissues by blood monocytes that can adopt genotypic and phenotypic features of the residents. However, little is known about the residency and functional properties of infiltrating macrophages after an inflammatory challenge. The meninges of the central nervous system (CNS) are populated by a dense network of specialized macrophages that act as resident immune sentinels. Here we show that following lymphocytic choriomeningitis virus infection resident meningeal macrophages become activated by innate inflammatory cytokines, acquire viral antigen, and interact directly with infiltrating cytotoxic T lymphocytes (CTL), which leads to their depletion. Concurrently, the meninges are heavily infiltrated by peripherally-derived inflammatory monocytes that engraft the meningeal niche and remain in situ for months after viral clearance. This engraftment leads to phenotypic and functional changes in the pool of resident meningeal macrophages that depends in part on IFNγ signaling. These changes include loss of bacterial and immunoregulatory sensors that impede subsequent CNS immune reactions. Collectively, these data indicate that peripheral monocytes can engraft the meninges after an inflammatory challenge, imprinting the compartment with long-term defects in immune function.
2019-03-06 | GSE108647 | GEO
Project description:Infection drives long-term meningeal engraftment by inflammatory monocytes that impair central nervous system immunity
| PRJNA428167 | ENA
Project description:Infection drives long-term meningeal engraftment by inflammatory monocytes that impair central nervous system immunity [I]
| PRJNA427333 | ENA
Project description:Infection drives long-term meningeal engraftment by inflammatory monocytes that impair central nervous system immunity [II]
| PRJNA428169 | ENA
Project description:Tissue macrophages have an embryonic origin and can be replenished in some tissues under steady-state conditions by blood monocytes. However, little is known about the residency and properties of infiltrating monocytes after an inflammatory challenge. The meninges of the central nervous system (CNS) are populated by a dense network of macrophages that act as resident immune sentinels. Here we show that, following lymphocytic choriomeningitis virus infection, resident meningeal macrophages (MMs) acquired viral antigen and interacted directly with infiltrating cytotoxic T lymphocytes, which led to macrophage depletion. Concurrently, the meninges were infiltrated by inflammatory monocytes that engrafted the meningeal niche and remained in situ for months after viral clearance. This engraftment led to interferon-γ-dependent functional changes in the pool of MMs, including loss of bacterial and immunoregulatory sensors. Collectively, these data indicate that peripheral monocytes can engraft the meninges after an inflammatory challenge, imprinting the compartment with long-term defects in immune function.
| S-EPMC6481670 | biostudies-literature
Project description:Neuroimmune interactions are crucial for regulating immunity and inflammation. Recent studies have revealed that the central nervous system (CNS) senses peripheral inflammation and responds by releasing molecules that limit immune cell activation, thereby promoting tolerance and tissue integrity. However, the extent to which this is a bidirectional process, and whether peripheral immune cells also promote tolerance mechanisms in the CNS remains poorly defined. Here we report that helminth-induced type 2 inflammation promotes monocyte responses in the brain that are required to inhibit excessive microglial activation and host death. Mechanistically, infection-induced monocytes express YM1 that is sufficient to inhibit tumor necrosis factor production from activated microglia. Importantly, neuroprotective monocytes persist in the brain, and infected mice are protected from subsequent lipopolysaccharide-induced neuroinflammation months after infection-induced inflammation has resolved. These studies demonstrate that infiltrating monocytes promote CNS homeostasis in response to inflammation in the periphery and demonstrate that a peripheral infection can alter the immunologic landscape of the host brain.
| S-EPMC9478671 | biostudies-literature
Project description:The use of antiretroviral (ARV) drugs with central nervous system (CNS) penetration effectiveness (CPE) may be useful in the treatment of HIV-associated neurocognitive disorder (HAND) as well as targeting a CNS reservoir in strategies to achieve a functional cure for HIV. However, increased cognitive deficits are linked to at least one of these drugs (efavirenz). As mitochondrial dysfunction has been found with a number of ARVs, and as such can affect neuronal function, the objective of this study was to assess the effects of ARV with high CPE for toxicological profiles on presynaptic nerve terminal energy metabolism. This subcellular region is especially vulnerable in that a constant supply of ATP is required for the proper maintenance of neurotransmitter release and uptake supporting proper neuronal function. We evaluated the effects of acute treatment with ten different high CPE ARVs from five different drug classes on rat cortical and striatal nerve terminal bioenergetic function. While cortical nerve terminal bioenergetics were not altered, striatal nerve terminals exposed to efavirenz, nevirapine, abacavir, emtricitabine, zidovudine, darunavir, lopinavir, raltegravir, or maraviroc (but not indinavir) exhibit reduced mitochondrial spare respiratory capacity (SRC). Further examination of efavirenz and maraviroc revealed a concentration-dependent impairment of striatal nerve terminal maximal mitochondrial respiration and SRC as well as a reduction of intraterminal ATP levels. Depletion of ATP at the synapse may underlie its dysfunction and contribute to neuronal dysfunction in treated HIV infection.
| S-EPMC5726941 | biostudies-literature
Project description:The meninges forms a critical epithelial barrier, which protects the central nervous system (CNS), and therefore its prompt reconstruction after CNS injury is essential for reducing neuronal damage. Meningeal cells migrate into the lesion site after undergoing an epithelial-mesenchymal transition (EMT) and repair the impaired meninges. However, the molecular mechanisms of meningeal EMT remain largely undefined. Here we show that TGF-?1 and retinoic acid (RA) released from the meninges, together with oxygen tension, could constitute the mechanism for rapid meningeal reconstruction. AKAP12 is an effector of this mechanism, and its expression in meningeal cells is regulated by integrated upstream signals composed of TGF-?1, RA and oxygen tension. Functionally, AKAP12 modulates meningeal EMT by regulating the TGF-?1-non-Smad-SNAI1 signalling pathway. Collectively, TGF-?1, RA and oxygen tension can modulate the dynamic change in AKAP12 expression, causing prompt meningeal reconstruction after CNS injury by regulating the transition between the epithelial and mesenchymal states of meningeal cells.
| S-EPMC4348065 | biostudies-literature
Project description:Nervous system injury is a frequent result of cancer therapy involving cranial irradiation, leaving patients with marked memory and other neurobehavioral disabilities. Here, we report an unanticipated link between bone marrow and brain in the setting of radiation injury. Specifically, we demonstrate that bone marrow-derived monocytes and macrophages are essential for structural and functional repair mechanisms, including regeneration of cerebral white matter and improvement in neurocognitive function. Using a granulocyte-colony stimulating factor (G-CSF) receptor knockout mouse model in combination with bone marrow cell transplantation, MRI, and neurocognitive functional assessments, we demonstrate that bone marrow-derived G-CSF-responsive cells home to the injured brain and are critical for altering neural progenitor cells and brain repair. Additionally, compared with untreated animals, animals that received G-CSF following radiation injury exhibited enhanced functional brain repair. Together, these results demonstrate that, in addition to its known role in defense and debris removal, the hematopoietic system provides critical regenerative drive to the brain that can be modulated by clinically available agents.
| S-EPMC5749546 | biostudies-literature