Malaria is a disease with diverse symptoms depending on host immune status and pathogenicity of Plasmodium parasites. The continuous parasite growth within a host suggests mechanisms of immune evasion and/or inhibition. To identify pathways commonly inhibited by malaria infection, we infected C67BL/6 mice with four Plasmodium yoelii strains causing different disease phenotypes and 24 progeny of a genetic cross. mRNAs from mouse spleens day 1 and/or day 4 post infection (p.i.) were hybridized to a mouse microarray to identify activated or inhibited pathways, upstream regulators, and linkages to parasite genetic loci. Strong interferon responses were observed after infection with N67 strain, whereas initial inhibition and later activation of hematopoiesis pathways were found after infection with 17XNL parasite. Inhibition of pathways such as Th1 activation, dendritic cell (DC) maturation, and NFAT immune regulation were observed in mice infected with all the parasite strains day 4 p.i., suggesting universally inhibited immune pathways. Treatment of infected mice with antibodies against T cell receptors OX40 or CD28 to activate malaria-inhibited pathways enhanced host survival. Controlled activation of these pathways may provide important strategies for better disease management and for developing an effective vaccine.
Detection of host pathways universally inhibited after Plasmodium yoelii infection for immune intervention.
Sex, Specimen part
View SamplesAn invading pathogen will trigger specific host responses, which can be explored to identify genes functioning in pathogen recognition and elimination. Here we performed trans-species expression quantitative trait locus (ts-eQTL) analysis using genotypes of the Plasmodium yoelii malaria parasite and phenotypes of mouse gene expression. We significantly (LOD score3.0) linked 1,054 host genes to many parasite genetic loci. Clustering genome-wide pattern of LOD scores (GPLSs), which produced results different from those of direct expression level clustering, grouped host genes functioning in related pathways together, allowing accurate functional prediction of unknown genes. As proof of principle, 14 of 15 randomly selected genes unknown, but predicted to function in type I interferon (IFN-I) responses, were experimentally verified using gene over expression, shRNA knockdown, viral infection, and/or infection of KO mice. This study demonstrates an effective strategy for studying gene function, establishes a functional gene database, and identifies regulators in IFN-I pathways.
Genome-wide Analysis of Host-Plasmodium yoelii Interactions Reveals Regulators of the Type I Interferon Response.
Specimen part
View SamplesGene expression kinetics for BM-DM from C57BL/6 mouse stimulated with four different TLR ligands poly(I:C), R848, LPS, Pam3CSK4 either singly or in paired combination, for 1 hour, 4 hour, or 8 hour.
Systematic Investigation of Multi-TLR Sensing Identifies Regulators of Sustained Gene Activation in Macrophages.
Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Systematic Investigation of Multi-TLR Sensing Identifies Regulators of Sustained Gene Activation in Macrophages.
Treatment
View SamplesGene expression kinetics for BM-DM from C57BL/6 mice challenged by poly(I:C) , R848, poly(I:C)+R848 examined at 6 time points including 0.5, 1, 2, 4, 8, 12 h.
Systematic Investigation of Multi-TLR Sensing Identifies Regulators of Sustained Gene Activation in Macrophages.
Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Glutamine supplementation suppresses herpes simplex virus reactivation.
Specimen part
View SamplesMycobacterium tuberculosis infection (Mtb) is the leading cause of death due to a single infectious agent and among the top ten causes of all human death worldwide1. CD4 T cells are essential for resistance to Mtb infection, and for decades it has been thought that IFN production is the primary mechanism of CD4 T cell-mediated protection2,3. However, IFN responses do not correlate with host protection, and several reports have demonstrated that additional anti-tuberculous CD4 T cell effector functions remain unaccounted for4-8. Here we show that the TNF superfamily molecule CD153 (TNFSF8) is required for IFN-independent control of pulmonary Mtb infection by CD4 T cells. In Mtb infected mice, CD153 expression is highest on Ag-specific Th1 cells in the lung tissue parenchyma, but its induction does not require Th1 polarization. CD153 deficient mice develop high pulmonary but not splenic bacterial loads and succumb early to Mtb infection. Reconstitution of T cell-deficient hosts with either CD153-/- or IFN-/- CD4 T cells fails to rescue mice from early mortality, but reconstitution with a mixture of CD153-/- and IFN-/- CD4 T cells provides similar protection as WT T cells. In Mtb infected non-human primates, CD153 expression is much higher on Ag-specific CD4 T cells in the airways compared to the blood, and the frequency of Mtb-specific CD153-expressing CD4 T cells inversely correlates with bacterial loads in granulomas. In Mtb infected humans, CD153 defines a subset of highly polyfunctional Mtb-specific CD4 T cells that are much more abundant in individuals with controlled latent Mtb infection compared to those with active TB. In all three species, Mtb-specific CD8 T cells did not upregulate CD153 following peptide stimulation. Thus, we have identified expression of CD153 by CD4 T cells as a major immune mechanism of host protection against pulmonary Mtb infection.
No associated publication
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View SamplesThe innate immune system is the organisms first line of defense against pathogens. Pattern recognition receptors (PRRs) are responsible for sensing the presence of pathogen-associated molecules. The prototypic PRRs, the membrane-bound receptors of the Toll-like receptor (TLR) family, recognize pathogen-associated molecular patterns (PAMPs) and initiate an innate immune response through signaling pathways that depend on the adaptor molecules MyD88 and TRIF. Deciphering the differences in the complex signaling events that lead to pathogen recognition and initiation of the correct response remains challenging. Here we report the discovery of temporal changes in the protein signaling components involved in innate immunity. Using an integrated strategy combining unbiased proteomics, transcriptomics and macrophage stimulations with three different PAMPs, we identified differences in signaling between individual TLRs and revealed specifics of pathway regulation at the protein level.
Proteome and Secretome Analysis Reveals Differential Post-transcriptional Regulation of Toll-like Receptor Responses.
Specimen part, Cell line
View SamplesIL-17 and TNF-alpha synergistically induce surface expression of IL-13Ra2 on primary lung fibroblasts, rendering them unresponsive to IL-13. Neutralizing antibodies to IL-13Ra2 restored IL-13-mediated signaling and transcriptome studies confirmed IL-13Ra2 is an IL-13 decoy receptor.
TNF-α/IL-17 synergy inhibits IL-13 bioactivity via IL-13Rα2 induction.
Specimen part, Cell line
View SamplesActivation of the TLR4 signaling pathway by LPS leads to induction of both inflammatory and interferon-stimulated genes, however, the mechanisms through which these coordinately activated transcriptional programs are balanced to promote an optimal innate immune response remain poorly understood. In a genome-wide siRNA screen of the LPS-induced TNF- response in macrophages, we identified the interferon-stimulated protein IFIT1 as a negative regulator of the inflammatory gene program. Transcriptional profiling further identified an unexpected positive regulatory role for IFIT1 in type I interferon expression, implicating IFIT1 as a reciprocal modulator of LPS-induced gene classes. We demonstrate that these effects of IFIT1 are mediated through modulation of a Sin3A-HDAC2 transcriptional regulatory complex at LPS-induced gene loci. Beyond the well-studied role of cytosolic IFIT1 in restricting viral replication, our data demonstrate an unappreciated function for nuclear IFIT1 in differential transcriptional regulation of separate branches of the LPS-induced gene program.
No associated publication
Treatment
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