scholarly journals Aging-induced type I interferon response at the choroid plexus negatively affects brain function

Science ◽  
2014 ◽  
Vol 346 (6205) ◽  
pp. 89-93 ◽  
Author(s):  
Kuti Baruch ◽  
Aleksandra Deczkowska ◽  
Eyal David ◽  
Joseph M. Castellano ◽  
Omer Miller ◽  
...  

Aging-associated cognitive decline is affected by factors produced inside and outside the brain. By using multiorgan genome-wide analysis of aged mice, we found that the choroid plexus, an interface between the brain and the circulation, shows a type I interferon (IFN-I)–dependent gene expression profile that was also found in aged human brains. In aged mice, this response was induced by brain-derived signals, present in the cerebrospinal fluid. Blocking IFN-I signaling within the aged brain partially restored cognitive function and hippocampal neurogenesis and reestablished IFN-II–dependent choroid plexus activity, which is lost in aging. Our data identify a chronic aging-induced IFN-I signature, often associated with antiviral response, at the brain’s choroid plexus and demonstrate its negative influence on brain function, thereby suggesting a target for ameliorating cognitive decline in aging.

mBio ◽  
2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Douglas R. Wilcox ◽  
Stephen S. Folmsbee ◽  
William J. Muller ◽  
Richard Longnecker

ABSTRACTNewborns are significantly more susceptible to severe viral encephalitis than adults, with differences in the host response to infection implicated as a major factor. However, the specific host signaling pathways responsible for differences in susceptibility and neurologic morbidity have remained unknown. In a murine model of HSV encephalitis, we demonstrated that the choroid plexus (CP) is susceptible to herpes simplex virus 1 (HSV-1) early in infection of the newborn but not the adult brain. We confirmed susceptibility of the CP to HSV infection in a human case of newborn HSV encephalitis. We investigated components of the type I interferon (IFN) response in the murine brain that might account for differences in cell susceptibility and found that newborns have a dampened interferon response and significantly lower basal levels of the alpha/beta interferon (IFN-α/β) receptor (IFNAR) than do adults. To test the contribution of IFNAR to restricting infection from the CP, we infected IFNAR knockout (KO) adult mice, which showed restored CP susceptibility to HSV-1 infection in the adult. Furthermore, reduced IFNAR levels did not account for differences we found in the basal levels of several other innate signaling proteins in the wild-type newborn and the adult, including protein kinase R (PKR), that suggested specific regulation of innate immunity in the developing brain. Viral targeting of the CP, a region of the brain that plays a critical role in neurodevelopment, provides a link between newborn susceptibility to HSV and long-term neurologic morbidity among survivors of newborn HSV encephalitis.IMPORTANCECompared to adults, newborns are significantly more susceptible to severe disease following HSV infection. Over half of newborn HSV infections result in disseminated disease or encephalitis, with long-term neurologic morbidity in 2/3 of encephalitis survivors. We investigated differences in host cell susceptibility between newborns and adults that contribute to severe central nervous system disease in the newborn. We found that, unlike the adult brain, the newborn choroid plexus (CP) was susceptible early in HSV-1 infection. We demonstrated that IFN-α/β receptor levels are lower in the newborn brain than in the adult brain and that deletion of this receptor restores susceptibility of the CP in the adult brain. The CP serves as a barrier between the blood and the cerebrospinal fluid and plays a role in proper neurodevelopment. Susceptibility of the newborn choroid plexus to HSV-1 has important implications in viral spread to the brain and, also, in the neurologic morbidity following HSV encephalitis.


2019 ◽  
Vol 10 ◽  
Author(s):  
Maja Studencka-Turski ◽  
Gonca Çetin ◽  
Heike Junker ◽  
Frédéric Ebstein ◽  
Elke Krüger

2016 ◽  
Vol 114 (1) ◽  
pp. E95-E104 ◽  
Author(s):  
Eugene Drokhlyansky ◽  
Didem Göz Aytürk ◽  
Timothy K. Soh ◽  
Ryan Chrenek ◽  
Elaine O’Loughlin ◽  
...  

The brain has a tightly regulated environment that protects neurons and limits inflammation, designated “immune privilege.” However, there is not an absolute lack of an immune response. We tested the ability of the brain to initiate an innate immune response to a virus, which was directly injected into the brain parenchyma, and to determine whether this response could limit viral spread. We injected vesicular stomatitis virus (VSV), a transsynaptic tracer, or naturally occurring VSV-derived defective interfering particles (DIPs), into the caudate–putamen (CP) and scored for an innate immune response and inhibition of virus spread. We found that the brain parenchyma has a functional type I interferon (IFN) response that can limit VSV spread at both the inoculation site and among synaptically connected neurons. Furthermore, we characterized the response of microglia to VSV infection and found that infected microglia produced type I IFN and uninfected microglia induced an innate immune response following virus injection.


2021 ◽  
Author(s):  
Leah C Dorman ◽  
Phi T Nguyen ◽  
Caroline C Escoubas ◽  
Ilia D Vainchtein ◽  
Yinghong Xiao ◽  
...  

Microglia, the innate immune cells of the brain, are exquisitely sensitive to dynamic changes in the brain environment. We used single cell RNA sequencing to define glial responses in the early postnatal somatosensory cortex after partial whisker lesion, revealing transcriptomic shifts in both astrocytes and microglia during the resulting topographic remapping. The most distinct change was the emergence of a type I interferon (IFN-I) responsive microglia population that was rare in the resting cortex but expanded 20-fold after whisker deprivation. The top gene candidate in this cluster, Ifitm3, marked a conserved but transient subset of microglia that were in the process of phagocytosing whole cells. IFITM3 protein identified this subset in vivo, where it was enriched in early microglial phagosomes. Loss of canonical IFN-I signaling in Ifnar1-/- animals resulted in abnormal 'bubble' microglia with deficient phagolysosomal processing. In a meta-analysis of transcriptomes, we identified the IFN-I signature in microglia across a range of pathologies. We identified phagocytic IFITM3+ microglia in two murine disease models: SARS-CoV-2 infection and Alzheimer's Disease. These data reveal the potential of transcriptional profiling after defined perturbation to elicit transient microglial states, and identify a novel role for IFN-I signaling in regulating microglial phagocytosis.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii109-ii109
Author(s):  
Brandon Wummer ◽  
Sadeem Qdaisat ◽  
Adam Grippin ◽  
Aida Karachi ◽  
Frances Weidert ◽  
...  

Abstract BACKGROUND Molecular drivers of cancer immunogenicity in brain tumors are still being unraveled. While BATF3 expression, STING, and interferon response factors (IRFs) are necessary for cancer immunogenicity, the presence of type I interferon (IFN-I) is contextual having been reported to elicit both anti-tumoral and pro-tumoral effects. A better understanding of IFN-I signaling mechanisms is necessary to elucidate drivers of brain cancer immunogenicity and resistance. OBJECTIVE We sought to assess the role of IFN-I signaling in brain tumor immunogenicity and response to immune checkpoint inhibitors (ICIs) in ICI sensitive brain tumor models (i.e. GL261). We then sought to develop strategies to reset IFN-I signaling in ICI resistant brain tumor models (i.e. KR158b). METHODS To reset IFN-I signaling in immunologically ‘cold’ tumors unresponsive to ICIs, we developed lipid-nanoparticles (NPs) to deliver mRNA payloads to the brain tumor microenvironment (TME). RESULTS In immune-sensitive GL261 tumors, we showed that early release of IFN-I unlocks cancer immunogenicity and ICI response. Blockade of IFN-I during tumorigenesis (within 24h, but not days later) increases tumorigenicity and abrogates ICI activity in sensitive tumors. In ICI resistant KR158b tumors, we show that systemic administration of tumor-derived RNA-NPs localize to myeloid cells within the TME for simultaneous activation of multiple innate pathways including BATF3 (necessary for effector DCs), IRF5 (necessary for M2 to M1 macrophage reprograming), and IRF7 (necessary for IFN-I production). These RNA-NPs induce near-immediate release of IFN-I (within hours), reprogram the brain TME in an IFNAR1 (IFN-I receptor) dependent manner, and elicit significant anti-KR158b efficacy as a monotherapy. Following IFNAR1 blockade, RNA-NP mediated anti-tumor efficacy was abrogated. We demonstrated safety of tumor-specific RNA-NPs (derived from KR158b) in acute/chronic GLP toxicity studies without normal-brain cross-reactivity, and confirmed feasibility/safety and immunologic activity in large-animal studies. FUTURE DIRECTIONS We have since received FDA-IND approval for first-in-human trials (IND#BB-19304) in glioblastoma patients.


2021 ◽  
Author(s):  
Nunya Chotiwan ◽  
Stefanie M.A. Willekens ◽  
Erin Schexnaydre ◽  
Max Hahn ◽  
Federico Morini ◽  
...  

Neurotropic virus infections cause tremendous disease burden. Methods visualizing infection in the whole brain remain unavailable which greatly impedes understanding of viral neurotropism and pathogenesis. We devised an approach to visualize the distribution of neurotropic virus infection in whole mouse brain ex vivo. Optical projection tomography (OPT) signal was coregistered with a unique magnetic resonance imaging (MRI) brain template, enabling precise anatomical mapping of viral distribution, and the effect of type I interferon on distribution of infection was analyzed. Guided by OPT-MR, we show that Langat virus specifically targets sensory brain systems and the lack of type I interferon response results in an anatomical shift in infection patterns in the brain. We confirm this regional tropism, observed with whole brain OPT-MRI, by confocal and electron microscopy to provide unprecedented insight into viral neurotropism. This approach can be applied to any fluorescently labeled target in the brain.


2018 ◽  
Author(s):  
Matthew Simon ◽  
Michael Van Meter ◽  
Julia Ablaeva ◽  
Zhonghe Ke ◽  
Raul S. Gonzalez ◽  
...  

SUMMARYMice deficient for SIRT6 exhibit a severely shortened lifespan, growth retardation, and highly elevated LINE1 (L1) activity. Here we report that SIRT6 deficient cells and tissues accumulate abundant cytoplasmic L1 cDNA which triggers massive type I interferon response via activation of cGAS. Remarkably, nucleoside reverse transcriptase inhibitors (NRTIs), which inhibit L1 retrotransposition, significantly improved health and lifespan of SIRT6 knockout mice and completely rescued type I interferon response. In tissue culture, inhibition of L1 with siRNA or NRTIs abrogated type I interferon response, in addition to a significant reduction of DNA damage markers. These results indicate that L1 activation contributes to the pathologies of SIRT6 knockout mice. Similarly, L1 transcription, cytoplasmic cDNA copy number and type I interferons were elevated in the wild type aged mice. As sterile inflammation is a hallmark of aging we propose that modulating L1 activity may be an important strategy for attenuating age-related pathologies.HighlightsSIRT6 KO mice accumulate L1 cDNA triggering type I interferon response via cGAS pathwayWild type aged mice accumulate L1 cDNA and display type I interferon responseReverse transcriptase inhibitors rescue type I interferon response and DNA damageReverse transcriptase inhibitors extend lifespan and improve health of SIRT6 KO mice


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