scholarly journals A virus hosted in malaria-infected blood protects against T cell-mediated inflammatory diseases by impairing DC function in a type I IFN-dependent manner

2019 ◽  
Author(s):  
Ali Hassan ◽  
Myriam F. Wlodarczyk ◽  
Mehdi Benamar ◽  
Emilie Bassot ◽  
Anna Salvioni ◽  
...  

AbstractCo-infections shape the host immune status, thereby influencing the development of inflammatory diseases, which can result in detrimental or beneficial effects. For example, co-infections with concurrent Plasmodium species can alter malaria clinical evolution and malaria infection itself has the ability to modulate autoimmune reactions but, in both cases, the underlying mechanisms remain ill-defined.Here, we demonstrate that the protective effects of certain rodent malaria strains on T cell-mediated inflammatory pathologies are due to an RNA virus co-hosted in malaria-parasitized blood. We show that live as well as extracts of blood parasitized by P. berghei K173 or P. yoelii 17X YM, confer full protection against Pb ANKA (PbA)-induced Experimental Cerebral Malaria (ECM) and MOG/CFA-induced experimental autoimmune encephalomyelitis (EAE), and that this is associated with a strong type I IFN signature. We detected the presence of a viral element, the RNA virus Lactate Dehydrogenase-elevating Virus (LDV), in the protective Plasmodium stabilates and we established that infection with LDV alone recapitulates the protective effects on ECM and EAE. In ECM, we further show that protection results from an IFN-I-mediated reduction in the abundance of splenic conventional dendritic cell and in their ability to produce the Th1-inducing IL-12p70, leading to a decrease in pathogenic CD4+ Th1 responses. In EAE, protection is achieved by IFN-I mediated blunting of IL-12 and IL-23, preventing the differentiation of IFN-γ-, IL-17- and GM-CSF-producing encephalitogenic CD4+ T cells.Thus, our results identify a virus that is co-hosted in several Plasmodium stabilates across the community and has major consequences on the host immune system. Moreover, our data emphasize the importance of considering concurrent infections for the understanding of autoimmunity and malaria-associated inflammatory complications.

mBio ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Ali Hassan ◽  
Myriam F. Wlodarczyk ◽  
Mehdi Benamar ◽  
Emilie Bassot ◽  
Anna Salvioni ◽  
...  

ABSTRACT Coinfections shape immunity and influence the development of inflammatory diseases, resulting in detrimental or beneficial outcome. Coinfections with concurrent Plasmodium species can alter malaria clinical evolution, and malaria infection itself can modulate autoimmune reactions. Yet, the underlying mechanisms remain ill defined. Here, we demonstrate that the protective effects of some rodent malaria strains on T cell-mediated inflammatory pathologies are due to an RNA virus cohosted in malaria-parasitized blood. We show that live and extracts of blood parasitized by Plasmodium berghei K173 or Plasmodium yoelii 17X YM, protect against P. berghei ANKA-induced experimental cerebral malaria (ECM) and myelin oligodendrocyte glycoprotein (MOG)/complete Freund’s adjuvant (CFA)-induced experimental autoimmune encephalomyelitis (EAE), and that protection is associated with a strong type I interferon (IFN-I) signature. We detected the presence of the RNA virus lactate dehydrogenase-elevating virus (LDV) in the protective Plasmodium stabilates and we established that LDV infection alone was necessary and sufficient to recapitulate the protective effects on ECM and EAE. In ECM, protection resulted from an IFN-I-mediated reduction in the abundance of splenic conventional dendritic cell and impairment of their ability to produce interleukin (IL)-12p70, leading to a decrease in pathogenic CD4+ Th1 responses. In EAE, LDV infection induced IFN-I-mediated abrogation of IL-23, thereby preventing the differentiation of granulocyte-macrophage colony-stimulating factor (GM-CSF)-producing encephalitogenic CD4+ T cells. Our work identifies a virus cohosted in several Plasmodium stabilates across the community and deciphers its major consequences on the host immune system. More generally, our data emphasize the importance of considering contemporaneous infections for the understanding of malaria-associated and autoimmune diseases. IMPORTANCE Any infection modifies the host immune status, potentially ameliorating or aggravating the pathophysiology of a simultaneous inflammatory condition. In the course of investigating how malaria infection modulates the severity of contemporaneous inflammatory diseases, we identified a nonpathogenic mouse virus in stabilates of two widely used rodent parasite lines: Plasmodium berghei K173 and Plasmodium yoelii 17X YM. We established that the protective effects of these Plasmodium lines on cerebral malaria and multiple sclerosis are exclusively due to this virus. The virus induces a massive type I interferon (IFN-I) response and causes quantitative and qualitative defects in the ability of dendritic cells to promote pathogenic T cell responses. Beyond revealing a possible confounding factor in rodent malaria models, our work uncovers some bases by which a seemingly innocuous viral (co)infection profoundly changes the immunopathophysiology of inflammatory diseases.


2021 ◽  
Vol 119 (1) ◽  
pp. e2111115119
Author(s):  
Zhongshun Liu ◽  
Congwei Jiang ◽  
Zhangmengxue Lei ◽  
Sihan Dong ◽  
Linlin Kuang ◽  
...  

Type I interferons (IFNs) are the first frontline of the host innate immune response against invading pathogens. Herein, we characterized an unknown protein encoded by phospholipase A2 inhibitor and LY6/PLAUR domain-containing (PINLYP) gene that interacted with TBK1 and induced type I IFN in a TBK1- and IRF3-dependent manner. Loss of PINLYP impaired the activation of IRF3 and production of IFN-β induced by DNA virus, RNA virus, and various Toll-like receptor ligands in multiple cell types. Because PINLYP deficiency in mice engendered an early embryonic lethality in mice, we generated a conditional mouse in which PINLYP was depleted in dendritic cells. Mice lacking PINLYP in dendritic cells were defective in type I IFN induction and more susceptible to lethal virus infection. Thus, PINLYP is a positive regulator of type I IFN innate immunity and important for effective host defense against viral infection.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Norzawani Buang ◽  
Lunnathaya Tapeng ◽  
Victor Gray ◽  
Alessandro Sardini ◽  
Chad Whilding ◽  
...  

AbstractThe majority of patients with systemic lupus erythematosus (SLE) have high expression of type I IFN-stimulated genes. Mitochondrial abnormalities have also been reported, but the contribution of type I IFN exposure to these changes is unknown. Here, we show downregulation of mitochondria-derived genes and mitochondria-associated metabolic pathways in IFN-High patients from transcriptomic analysis of CD4+ and CD8+ T cells. CD8+ T cells from these patients have enlarged mitochondria and lower spare respiratory capacity associated with increased cell death upon rechallenge with TCR stimulation. These mitochondrial abnormalities can be phenocopied by exposing CD8+ T cells from healthy volunteers to type I IFN and TCR stimulation. Mechanistically these ‘SLE-like’ conditions increase CD8+ T cell NAD+ consumption resulting in impaired mitochondrial respiration and reduced cell viability, both of which can be rectified by NAD+ supplementation. Our data suggest that type I IFN exposure contributes to SLE pathogenesis by promoting CD8+ T cell death via metabolic rewiring.


2014 ◽  
Vol 7 (5) ◽  
pp. 1151-1164 ◽  
Author(s):  
A Jayaraman ◽  
D J Jackson ◽  
S D Message ◽  
R M Pearson ◽  
J Aniscenko ◽  
...  

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi181-vi181
Author(s):  
Yuanfan Yang ◽  
Michael Brown ◽  
Kevin Stevenson ◽  
Giselle lopez ◽  
Reb Kornahrens ◽  
...  

Abstract Immunotherapy with polio:rhinovirus recombinant (PVSRIPO) has shown evidence of efficacy in a phase I clinical trial for recurrent GBM, resulting in durable radiographic responses and 21% long-term survival at 36 months. Ongoing research aims to enhance the clinical response rate by resolving the mechanisms of action and therapy resistance in vivo, thereby devising more effective therapies. Mouse glioma (CT2A) cells were intracranially implanted (day 0) in transgenic mice carrying poliovirus receptor CD155, and treated with intratumor PVSRIPO (5×105 pfu; day 6) to dissect early and late events following therapy. A blinded pathological review of 45 post-treatment tumors was performed. On day 8, a histological response, featured by tumor dissociation and shrinkage, with inflammation and microglia enrichment in the treated hemisphere, was common in PVSRIPO group (6/7) compared to controls (0/4). However, the response rate fell over time (7/12 on day 12; 1/7 on day 15) and the therapy was overcome by aggressive tumor regrowth. RNAseq was performed and Gene Set Enrichment Analysis of the tumor microenvironment revealed an acute type-I interferon (IFN)-related inflammation, correlating with the histological findings of profound proinflammatory engagement of microglia (Iba1+) widespread in the treated hemisphere. Microglia proliferation (Ki67+) was observed in the treated hemisphere, likely resulting from PVSRIPO infection, in CT2A and B16 intracranial models. This suggests an association of adaptive antitumor immunity—elicited by immediate intratumor type-I IFN-dominant inflammation—with tumor regression. Thus, buttressing type-I IFN directed antitumor CD8+T cell immunity, e.g. with blockade of the PD1:PD-L1 immune checkpoint, might contribute to tumor remission. Indeed, combination therapy with αPD-L1 antibody in the CT2A model showed longer median survival and higher long-term remission rate compared to monotherapy alone; CD8 T cell depletion can completely abrogate this efficacy with this therapy combination, confirming the role of anti-tumor immunity in this approach.


1994 ◽  
Vol 14 (8) ◽  
pp. 5099-5107 ◽  
Author(s):  
N Koyano-Nakagawa ◽  
J Nishida ◽  
D Baldwin ◽  
K Arai ◽  
T Yokota

The CT/GC-rich region (-76 to -47) is one transcriptional regulatory region of the interleukin-3 (IL-3) gene which confers basic transcriptional activity and responds to trans-activation by human T-cell leukemia virus type I-encoded Tax. We isolated three types of cDNAs encoding Cys2/His2-type zinc finger proteins that bind to this region. Two were identical to known transcription factors, EGR1 and EGR2, and the other clone, named DB1, encoded a novel protein of 516 amino acids with six zinc finger motifs. DB1 mRNA was present in human tissues, ubiquitously. Two constitutive transcripts of 4.0 and 4.8 kb in length were present in Jurkat cells. Electrophoretic mobility shift assay, with specific antibodies, showed that DB1 constitutively binds to this region whereas EGR1 binds in a T-cell activation-dependent manner. Overexpression of DB1 in Jurkat cells had no detectable effect on the transcription activity of the IL-3 promoter, in a transient-transfection assay. EGR1 and EGR2 increased IL-3 promoter activity when the transfected cells were stimulated with phorbol-12-myristate-13-acetate and A23187. When DB1 was cotransfected with a Tax expression vector, transcription activity of the IL-3 promoter induced by Tax was significantly increased, while EGR1 and EGR2 were without effect. These results suggest that EGR1 has a role in inducible transcription of the IL-3 gene, while DB1 sustains basal transcriptional activity and also cooperates with Tax to activate the IL-3 promoter.


2021 ◽  
Author(s):  
Qinjian Li ◽  
Fei Xie ◽  
Yang Yi ◽  
Pengxiang Zhao ◽  
Xin Zhang ◽  
...  

AbstractSince Ohsawa et al. reported a biological antioxidant function of hydrogen in 2007, researchers have now shown it to exert protective effects in a wide range of human and animal disease models. Clinical observations and scientific arguments suggest that a selective scavenging property of H2 cannot adequately explain the beneficial effects of hydrogen. However, there is no experiment challenging the original published data, which suggested that molecular hydrogen dissolved in solution reacts with hydroxyl radicals in cell-free systems. Here we report that a hydrogen-saturated solution (0.6 mM) did not significantly reduce hydroxyl radicals in the Fenton system using 1 mM H2O2. We replicated the same condition as Ohsawa’s study (i.e. 5 μM H2O2), and observed a decrease in •OH radicals in both the H2-rich and N2-rich solutions, which may be caused by a decreased dissolved oxygen concentration. Finally, we determined the effect of hydrogen on a high-valence iron enzyme, horseradish peroxidase (HRP), and found that hydrogen could directly increase HRP activity in a dose-dependent manner. Overall, these results indicate that although H2 and •OH can react, the reaction rate is too low to have physiological function. The target of hydrogen is more complex, and its interaction with enzymes or other macro-molecules deserve more attention and in-depth study.


2019 ◽  
Vol 39 (12) ◽  
Author(s):  
Fangyi Zhang ◽  
Xuefeng Lin ◽  
Xiaodong Yang ◽  
Guangjian Lu ◽  
Qunmei Zhang ◽  
...  

Abstract Increasing evidence has indicated that microRNAs (miRNAs) have essential roles in innate immune responses to various viral infections; however, the role of miRNAs in H1N1 influenza A virus (IAV) infection is still unclear. The present study aimed to elucidate the role and mechanism of miRNAs in IAV replication in vitro. Using a microarray assay, we analyzed the expression profiles of miRNAs in peripheral blood from IAV patients. It was found that miR-132-3p was significantly up-regulated in peripheral blood samples from IAV patients. It was also observed that IAV infection up-regulated the expression of miR-132-3p in a dose- and time-dependent manner. Subsequently, we investigated miR-132-3p function and found that up-regulation of miR-132-3p promoted IAV replication, whereas knockdown of miR-132-3p repressed replication. Meanwhile, overexpression of miR-132-3p could inhibit IAV triggered INF-α and INF-β production and IFN-stimulated gene (ISG) expression, including myxovirus protein A (MxA), 2′,5′-oligoadenylate synthetases (OAS), and double-stranded RNA-dependent protein kinase (PKR), while inhibition of miR-132-3p enhanced IAV triggered these effects. Of note, interferon regulatory factor 1 (IRF1), a well-known regulator of the type I IFN response, was identified as a direct target of miR-132-3p during HIN1 IAV infection. Furthermore, knockdown of IRF1 by si-IRF1 reversed the promoting effects of miR-132-3p inhibition on type I IFN response. Taken together, up-regulation of miR-132-3p promotes IAV replication by suppressing type I IFN response through its target gene IRF1, suggesting that miR-132-3p could represent a novel potential therapeutic target of IAV treatment.


2009 ◽  
Vol 182 (5) ◽  
pp. 2786-2794 ◽  
Author(s):  
Zhengguo Xiao ◽  
Kerry A. Casey ◽  
Stephen C. Jameson ◽  
Julie M. Curtsinger ◽  
Matthew F. Mescher

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