27 research outputs found

    Trypanosoma cruzi Adjuvants Potentiate T Cell-Mediated Immunity Induced by a NY-ESO-1 Based Antitumor Vaccine

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    Immunological adjuvants that induce T cell-mediate immunity (TCMI) with the least side effects are needed for the development of human vaccines. Glycoinositolphospholipids (GIPL) and CpGs oligodeoxynucleotides (CpG ODNs) derived from the protozoa parasite Trypanosoma cruzi induce potent pro-inflammatory reaction through activation of Toll-Like Receptor (TLR)4 and TLR9, respectively. Here, using mouse models, we tested the T. cruzi derived TLR agonists as immunological adjuvants in an antitumor vaccine. For comparison, we used well-established TLR agonists, such as the bacterial derived monophosphoryl lipid A (MPL), lipopeptide (Pam3Cys), and CpG ODN. All tested TLR agonists were comparable to induce antibody responses, whereas significant differences were noticed in their ability to elicit CD4+ T and CD8+ T cell responses. In particular, both GIPLs (GTH, and GY) and CpG ODNs (B344, B297 and B128) derived from T. cruzi elicited interferon-gamma (IFN-Îł) production by CD4+ T cells. On the other hand, the parasite derived CpG ODNs, but not GIPLs, elicited a potent IFN-Îł response by CD8+ T lymphocytes. The side effects were also evaluated by local pain (hypernociception). The intensity of hypernociception induced by vaccination was alleviated by administration of an analgesic drug without affecting protective immunity. Finally, the level of protective immunity against the NY-ESO-1 expressing melanoma was associated with the magnitude of both CD4+ T and CD8+ T cell responses elicited by a specific immunological adjuvant

    Type I Interferon Induction by Neisseria gonorrhoeae: Dual Requirement of Cyclic GMP-AMP Synthase and Toll-like Receptor 4

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    Submitted by Nuzia Santos ([email protected]) on 2017-04-12T18:33:43Z No. of bitstreams: 1 ve_Andrade_Warrison_Type I Interferon_CPqRR_2016.pdf: 4696746 bytes, checksum: e38d65ae3a03ce767b88e6c42879aa73 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2017-04-12T18:42:07Z (GMT) No. of bitstreams: 1 ve_Andrade_Warrison_Type I Interferon_CPqRR_2016.pdf: 4696746 bytes, checksum: e38d65ae3a03ce767b88e6c42879aa73 (MD5)Made available in DSpace on 2017-04-12T18:42:07Z (GMT). No. of bitstreams: 1 ve_Andrade_Warrison_Type I Interferon_CPqRR_2016.pdf: 4696746 bytes, checksum: e38d65ae3a03ce767b88e6c42879aa73 (MD5) Previous issue date: 2016University of Massachusetts Medical School. Division of Infectious Diseases. Worcester, MA, USA/University of Massachusetts Medical School. Department of Medicine. Program in Innate Immunity. Worcester, MA, USAUniversity of Massachusetts Medical School. Division of Infectious Diseases. Worcester, MA, USAUniversity of Massachusetts Medical School. Proteomics and Mass Spectrometry Facility. Worcester, MA, USA/University of Massachusetts Medical School. Department of Biochemistry and Molecular Pharmacology. Worcester, MA, USAUniversity of Massachusetts Medical School. Proteomics and Mass Spectrometry Facility. Worcester, MA, USA/University of Massachusetts Medical School. Department of Biochemistry and Molecular Pharmacology. Worcester, MA, USAUniversity of Wisconsin-Madison. Department of Medical Microbiology and Immunology. Madison, WI, USAUniversitĂ€tsklinikum Bonn. Institute of Molecular Medicine. Bonn,GermanyUniversitĂ€tsklinikum Bonn. Institute of Molecular Medicine. Bonn,Germany Katherine A. Fitzgerald/University of Massachusetts Medical School. Division of Infectious Diseases. Worcester, MA, USA/University of Massachusetts Medical School. Department of Medicine. Program in Innate Immunity. Worcester, MA, USA/Norwegian University of Science and Technology. Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine. Trondheim, NorwayUniversity of Massachusetts Medical School. Division of Infectious Diseases. Worcester, MA, USA/University of Massachusetts Medical School. Department of Medicine. Program in Innate Immunity.University of Massachusetts Medical School. Division of Infectious Diseases. Worcester, MA, USA/ University of Massachusetts Medical School. Department of Medicine. Program in Innate Immunity/Fundação Oswaldo Cruz. Centro de Pesquisas RenĂ© Rachou. Belo Horizonte, MG, BrazilThe innate immune system is the first line of defense against Neisseria gonorrhoeae (GC). Exposure of cells to GC lipooligosaccharides induces a strong immune response, leading to type I interferon (IFN) production via TLR4/MD-2. In addition to living freely in the extracellular space, GC can invade the cytoplasm to evade detection and elimination. Double-stranded DNA introduced into the cytosol binds and activates the enzyme cyclic-GMP-AMP synthase (cGAS), which produces 2â€Č3â€Č-cGAMP and triggers STING/TBK-1/IRF3 activation, resulting in type I IFN expression. Here, we reveal a cytosolic response to GC DNA that also contributes to type I IFN induction. We demonstrate that complete IFN-ÎČ induction by live GC depends on both cGAS and TLR4. Type I IFN is detrimental to the host, and dysregulation of iron homeostasis genes may explain lower bacteria survival in cGAS−/− and TLR4−/− cells. Collectively, these observations reveal cooperation between TLRs and cGAS in immunity to GC infection

    Group B Streptococcus Degrades Cyclic-di-AMP to Modulate STING-Dependent Type I Interferon Production

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    Induction of type I interferon (IFN) in response to microbial pathogens depends on a conserved cGAS-STING signaling pathway. The presence of DNA in the cytoplasm activates cGAS, while STING is activated by cyclic dinucleotides (cdNs) produced by cGAS or from bacterial origins. Here, we show that Group B Streptococcus (GBS) induces IFN-beta production almost exclusively through cGAS-STING-dependent recognition of bacterial DNA. However, we find that GBS expresses an ectonucleotidase, CdnP, which hydrolyzes extracellular bacterial cyclic-di-AMP. Inactivation of CdnP leads to c-di-AMP accumulation outside the bacteria and increased IFN-beta production. Higher IFN-beta levels in vivo increase GBS killing by the host. The IFN-beta overproduction observed in the absence of CdnP is due to the cumulative effect of DNA sensing by cGAS and STING-dependent sensing of c-di-AMP. These findings describe the importance of a bacterial c-di-AMP ectonucleotidase and suggest a direct bacterial mechanism that dampens activation of the cGAS-STING axis

    The IRAK1/IRF5 axis initiates IL-12 response by dendritic cells and control of Toxoplasma gondii infection

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    Summary: Activation of endosomal Toll-like receptor (TLR) 7, TLR9, and TLR11/12 is a key event in the resistance against the parasite Toxoplasma gondii. Endosomal TLR engagement leads to expression of interleukin (IL)-12 via the myddosome, a protein complex containing MyD88 and IL-1 receptor-associated kinase (IRAK) 4 in addition to IRAK1 or IRAK2. In murine macrophages, IRAK2 is essential for IL-12 production via endosomal TLRs but, surprisingly, Irak2−/− mice are only slightly susceptible to T. gondii infection, similar to Irak1−/− mice. Here, we report that upon T. gondii infection IL-12 production by different cell populations requires either IRAK1 or IRAK2, with conventional dendritic cells (DCs) requiring IRAK1 and monocyte-derived DCs (MO-DCs) requiring IRAK2. In both populations, we identify interferon regulatory factor 5 as the main transcription factor driving the myddosome-dependent IL-12 production during T. gondii infection. Consistent with a redundant role of DCs and MO-DCs, mutations that affect IL-12 production in both cell populations show high susceptibility to infection in vivo

    Cyclic GMP-AMP Synthase Is the Cytosolic Sensor of Plasmodium falciparum Genomic DNA and Activates Type I IFN in Malaria

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    Innate immune receptors have a key role in the sensing of malaria and initiating immune responses. As a consequence of infection, systemic inflammation emerges and is directly related to signs and symptoms during acute disease. We have previously reported that plasmodial DNA is the primary driver of systemic inflammation in malaria, both within the phagolysosome and in the cytosol of effector cells. In this article, we demonstrate that Plasmodium falciparum genomic DNA delivered to the cytosol of human monocytes binds and activates cyclic GMP-AMP synthase (cGAS). Activated cGAS synthesizes 2\u273\u27-cGAMP, which we subsequently can detect using liquid chromatography-tandem mass spectrometry. 2\u273\u27-cGAMP acts as a second messenger for STING activation and triggers TBK1/IRF3 activation, resulting in type I IFN production in human cells. This induction of type I IFN was independent of IFI16. Access of DNA to the cytosolic compartment is mediated by hemozoin, because incubation of purified malaria pigment with DNase abrogated IFN-beta induction. Collectively, these observations implicate cGAS as an important cytosolic sensor of P. falciparum genomic DNA and reveal the role of the cGAS/STING pathway in the induction of type I IFN in response to malaria parasites

    Combined action of nucleic acid-sensing Toll-like receptors and TLR11/TLR12 heterodimers imparts resistance to Toxoplasma gondii in mice

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    Triple-defective (3d) mice carrying a mutation in UNC93B1, a chaperone for the endosomal nucleic acid-sensing (NAS) Toll-like receptors TLR3, TLR7, and TLR9, are highly susceptible to Toxoplasma gondii infection. However, none of the single or even the triple NAS-TLR-deficient animals recapitulated the 3d susceptible phenotype to experimental toxoplasmosis. Investigating this further, we found that while parasite RNA and DNA activate innate immune responses via TLR7 and TLR9, TLR11 and TLR12 working as heterodimers are required for sensing and responding to Toxoplasma profilin. Consequently, the triple TLR7/TLR9/TLR11-deficient mice are highly susceptible to T. gondii infection, recapitulating the phenotype of 3d mice. Humans lack functional TLR11 and TLR12 genes. Consistently, human cells produce high levels of proinflammatory cytokines in response to parasite-derived RNA and DNA, but not to Toxoplasma profilin, supporting a more critical role for NAS-TLRs in human toxoplasmosis

    Enhanced Activity of NLRP3 Inflammasome in the Lung of Patients with Anti-Synthetase Syndrome

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    Anti-synthetase syndrome (ASSD) is an autoimmune disorder characterized by inflammatory interstitial lung disease (ILD). The main objective of this work was to quantify the concentrations of cytokines and molecules associated with inflammasome activation in bronchoalveolar lavage (BAL) of patients with ASSD and a comparison group of systemic sclerosis (SSc) patients. Cytokines and lactate dehydrogenase (LDH) were determined using the concentrated BAL protein. The activity of caspase-1 and concentration of NLRP3 with the protein purified from the cell pellet in each group of patients. We found higher caspase-1 levels in ASSD vs. SSc, 1.25 RFU vs. 0.75 RFU p = 0.003, and LDH levels at 0.15 OD vs. 0.09 OD p < 0.001. A significant difference was observed in molecules associated with inflammasome activation, IL-18: 1.42 pg/mL vs. 0.87 pg/mL p = 0.02 and IFN-γ: 0.9 pg/mL vs. 0.86 pg/mL, p = 0.01. A positive correlation was found between caspase-1 and LDH in the patients with ASSD Rho 0.58 (p = 0.008) but not in the SSc group. In patients with ASSD, greater caspase-1 and higher LDH activity were observed in BAL, suggesting cell death due to pyroptosis and activation of the inflammasome pathway

    Enhanced Activity of NLRP3 Inflammasome in the Lung of Patients with Anti-Synthetase Syndrome

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    Anti-synthetase syndrome (ASSD) is an autoimmune disorder characterized by inflammatory interstitial lung disease (ILD). The main objective of this work was to quantify the concentrations of cytokines and molecules associated with inflammasome activation in bronchoalveolar lavage (BAL) of patients with ASSD and a comparison group of systemic sclerosis (SSc) patients. Cytokines and lactate dehydrogenase (LDH) were determined using the concentrated BAL protein. The activity of caspase-1 and concentration of NLRP3 with the protein purified from the cell pellet in each group of patients. We found higher caspase-1 levels in ASSD vs. SSc, 1.25 RFU vs. 0.75 RFU p = 0.003, and LDH levels at 0.15 OD vs. 0.09 OD p p = 0.02 and IFN-Îł: 0.9 pg/mL vs. 0.86 pg/mL, p = 0.01. A positive correlation was found between caspase-1 and LDH in the patients with ASSD Rho 0.58 (p = 0.008) but not in the SSc group. In patients with ASSD, greater caspase-1 and higher LDH activity were observed in BAL, suggesting cell death due to pyroptosis and activation of the inflammasome pathway

    Apoptosis-associated speck-like protein containing a caspase recruitment domain inflammasomes mediate IL-1beta response and host resistance to Trypanosoma cruzi infection

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    The innate immune response to Trypanosoma cruzi infection comprises several pattern recognition receptors (PRRs), including TLR-2, -4, -7, and -9, as well as the cytosolic receptor Nod1. However, there are additional PRRs that account for the host immune responses to T. cruzi. In this context, the nucleotide-binding oligomerization domain-like receptors (NLRs) that activate the inflammasomes are candidate receptors that deserve renewed investigation. Following pathogen infection, NLRs form large molecular platforms, termed inflammasomes, which activate caspase-1 and induce the production of active IL-1beta and IL-18. In this study, we evaluated the involvement of inflammasomes in T. cruzi infection and demonstrated that apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) inflammasomes, including NLR family, pyrin domain-containing 3 (NLRP3), but not NLR family, caspase recruitment domain-containing 4 or NLR family, pyrin domain-containing 6, are required for triggering the activation of caspase-1 and the secretion of IL-1beta. The mechanism by which T. cruzi mediates the activation of the ASC/NLRP3 pathway involves K(+) efflux, lysosomal acidification, reactive oxygen species generation, and lysosomal damage. We also demonstrate that despite normal IFN-gamma production in the heart, ASC(-)/(-) and caspase-1(-)/(-) infected mice exhibit a higher incidence of mortality, cardiac parasitism, and heart inflammation. These data suggest that ASC inflammasomes are critical determinants of host resistance to infection with T. cruzi
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