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Nemet I, Funabashi M, Li XS, Dwidar M, Sangwan N, Skye SM, Romano KA, Cajka T, Needham BD, Mazmanian SK, Hajjar AM, Rey FE, Fiehn O, Tang WHW, Fischbach MA, Hazen SL. Microbe-derived uremic solutes enhance thrombosis potential in the host. mBio 2023; 14:e0133123. [PMID: 37947418 PMCID: PMC10746243 DOI: 10.1128/mbio.01331-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 09/25/2023] [Indexed: 11/12/2023] Open
Abstract
p-Cresol sulfate (pCS) and indoxyl sulfate (IS), gut microbiome-derived metabolites, are traditionally associated with cardiovascular disease (CVD) risks in the setting of impaired kidney function. While pharmacologic provision of pCS or IS can promote pro-thrombotic phenotypes, neither the microbial enzymes involved nor direct gut microbial production have been linked to CVD. Untargeted metabolomics was performed on a discovery cohort (n = 1,149) with relatively preserved kidney function, followed by stable isotope-dilution mass spectrometry quantification of pCS and IS in an independent validation cohort (n = 3,954). Genetic engineering of human commensals to produce p-cresol and indole gain-of-function and loss-of-function mutants, followed by colonization of germ-free mice, and studies on host thrombosis were performed. Systemic pCS and IS levels were independently associated with all-cause mortality. Both in vitro and within colonized germ-free mice p-cresol productions were recapitulated by collaboration of two organisms: a Bacteroides strain that converts tyrosine to 4-hydroxyphenylacetate, and a Clostridium strain that decarboxylates 4-hydroxyphenylacetate to p-cresol. We then engineered a single organism, Bacteroides thetaiotaomicron, to produce p-cresol, indole, or both metabolites. Colonizing germ-free mice with engineered strains, we show the gut microbial genes for p-cresol (hpdBCA) and indole (tryptophanase) are sufficient to confer a pro-thrombotic phenotype in vivo. Moreover, human fecal metagenomics analyses show that abundances of hpdBCA and tryptophanase are associated with CVD. These studies show that pCS and IS, two abundant microbiome-derived metabolites, play a broader potential role in CVD than was previously known. They also suggest that therapeutic targeting of gut microbial p-cresol- and indole-producing pathways represent rational targets for CVD.IMPORTANCEAlterations in gut microbial composition and function have been linked to numerous diseases. Identifying microbial pathways responsible for producing molecules that adversely impact the host is an important first step in the development of therapeutic interventions. Here, we first use large-scale clinical observations to link blood levels of defined microbial products to cardiovascular disease risks. Notably, the previously identified uremic toxins p-cresol sulfate and indoxyl sulfate were shown to predict 5-year mortality risks. After identifying the microbes and microbial enzymes involved in the generation of these uremic toxins, we used bioengineering technologies coupled with colonization of germ-free mice to show that the gut microbial genes that generate p-cresol and indole are sufficient to confer p-cresol sulfate and indoxyl sulfate formation, and a pro-thrombotic phenotype in vivo. The findings and tools developed serve as a critical step in both the study and targeting of these gut microbial pathways in vivo.
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Affiliation(s)
- Ina Nemet
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland, Ohio, USA
- Center for Microbiome & Human Health, Cleveland Clinic, Cleveland, Ohio, USA
| | - Masanori Funabashi
- Department of Bioengineering, Stanford University, Stanford, California, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, California, USA
- ChEM-H Institute, Stanford University, Stanford, California, USA
| | - Xinmin S. Li
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland, Ohio, USA
- Center for Microbiome & Human Health, Cleveland Clinic, Cleveland, Ohio, USA
| | - Mohammed Dwidar
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland, Ohio, USA
- Center for Microbiome & Human Health, Cleveland Clinic, Cleveland, Ohio, USA
| | - Naseer Sangwan
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland, Ohio, USA
- Center for Microbiome & Human Health, Cleveland Clinic, Cleveland, Ohio, USA
| | - Sarah M. Skye
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland, Ohio, USA
- Center for Microbiome & Human Health, Cleveland Clinic, Cleveland, Ohio, USA
| | - Kymberleigh A. Romano
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland, Ohio, USA
- Center for Microbiome & Human Health, Cleveland Clinic, Cleveland, Ohio, USA
| | - Tomas Cajka
- West Coast Metabolomics Center, University of California, Davis, California, USA
| | - Brittany D. Needham
- Departments of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | - Sarkis K. Mazmanian
- Departments of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | - Adeline M. Hajjar
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland, Ohio, USA
- Center for Microbiome & Human Health, Cleveland Clinic, Cleveland, Ohio, USA
| | - Federico E. Rey
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Oliver Fiehn
- West Coast Metabolomics Center, University of California, Davis, California, USA
| | - W. H. Wilson Tang
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland, Ohio, USA
- Center for Microbiome & Human Health, Cleveland Clinic, Cleveland, Ohio, USA
- Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Michael A. Fischbach
- Department of Bioengineering, Stanford University, Stanford, California, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, California, USA
- ChEM-H Institute, Stanford University, Stanford, California, USA
- Chan Zuckerberg Biohub, San Francisco, California, USA
| | - Stanley L. Hazen
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland, Ohio, USA
- Center for Microbiome & Human Health, Cleveland Clinic, Cleveland, Ohio, USA
- Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio, USA
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2
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Dwidar M, Buffa JA, Wang Z, Santos A, Tittle AN, Fu X, Hajjar AM, DiDonato JA, Hazen SL. Assembling the anaerobic gamma-butyrobetaine to TMA metabolic pathway in Escherichia fergusonii and confirming its role in TMA production from dietary L-carnitine in murine models. mBio 2023; 14:e0093723. [PMID: 37737636 PMCID: PMC10653785 DOI: 10.1128/mbio.00937-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 08/02/2023] [Indexed: 09/23/2023] Open
Abstract
IMPORTANCE The key atherosclerotic TMAO originates from the initial gut microbial conversion of L-carnitine and other dietary compounds into TMA. Developing therapeutic strategies to block gut microbial TMA production needs a detailed understanding of the different production mechanisms and their relative contributions. Recently, we identified a two-step anaerobic pathway for TMA production from L-carnitine through initial conversion by some microbes into the intermediate γBB which is then metabolized by other microbes into TMA. Investigational studies of this pathway, however, are limited by the lack of single microbes harboring the whole pathway. Here, we engineered E. fergusonii strain to harbor the whole two-step pathway and optimized the expression through cloning a specific chaperone from the original host. Inoculating germ-free mice with this recombinant E. fergusonii is enough to raise serum TMAO to pathophysiological levels upon L-carnitine feeding. This engineered microbe will facilitate future studies investigating the contribution of this pathway to cardiovascular disease.
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Affiliation(s)
- Mohammed Dwidar
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, Ohio, USA
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Jennifer A. Buffa
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, Ohio, USA
| | - Zeneng Wang
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, Ohio, USA
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Akeem Santos
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, Ohio, USA
| | - Aaron N. Tittle
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, Ohio, USA
| | - Xiaoming Fu
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, Ohio, USA
| | - Adeline M. Hajjar
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, Ohio, USA
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Joseph A. DiDonato
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, Ohio, USA
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Stanley L. Hazen
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, Ohio, USA
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Cardiovascular Medicine, Heart, Vascular, and Thoracic Institute, Cleveland Clinic, Cleveland, Ohio, USA
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3
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López-Yglesias AH, Lu CC, Lai MA, Quarles EK, Zhao X, Hajjar AM, Smith KD. FlgM is required to evade NLRC4-mediated host protection against flagellated Salmonella. Infect Immun 2023; 91:e0025523. [PMID: 37638725 PMCID: PMC10501211 DOI: 10.1128/iai.00255-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 07/07/2023] [Indexed: 08/29/2023] Open
Abstract
Salmonella enterica serovar Typhimurium is a leading cause of gastroenteritis worldwide and a deadly pathogen in children, immunocompromised patients, and the elderly. Salmonella induces innate immune responses through the NLRC4 inflammasome, which has been demonstrated to have distinct roles during systemic and mucosal detections of flagellin and non-flagellin molecules. We hypothesized that NLRC4 recognition of Salmonella flagellin is the dominant protective pathway during infection. To test this hypothesis, we used wild-type, flagellin-deficient, and flagellin-overproducing Salmonella to establish the role of flagellin in mediating NLRC4-dependent host resistance during systemic and mucosal infections in mice. We observed that during the systemic phase of infection, Salmonella efficiently evades NLRC4-mediated innate immunity. During mucosal Salmonella infection, flagellin recognition by the NLRC4 inflammasome pathway is the dominant mediator of protective innate immunity. Deletion of flgM results in constitutive expression of flagellin and severely limits systemic and mucosal Salmonella infections in an NLRC4 inflammasome-dependent manner. These data establish that recognition of Salmonella's flagellin by the NLRC4 inflammasome during mucosal infection is the dominant innate protective pathway for host resistance against the enteric pathogen and that FlgM-mediated evasion of the NLRC4 inflammasome enhances virulence and intestinal tissue destruction.
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Affiliation(s)
| | - Chun-Chi Lu
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Marvin A. Lai
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Ellen K. Quarles
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Xiaodan Zhao
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Adeline M. Hajjar
- Department of Comparative Medicine, University of Washington, Seattle, Washington, USA
| | - Kelly D. Smith
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
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4
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Wang M, Osborn LJ, Jain S, Meng X, Weakley A, Yan J, Massey WJ, Varadharajan V, Horak A, Banerjee R, Allende DS, Chan ER, Hajjar AM, Wang Z, Dimas A, Zhao A, Nagashima K, Cheng AG, Higginbottom S, Hazen SL, Brown JM, Fischbach MA. Strain dropouts reveal interactions that govern the metabolic output of the gut microbiome. Cell 2023; 186:2839-2852.e21. [PMID: 37352836 PMCID: PMC10299816 DOI: 10.1016/j.cell.2023.05.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 04/10/2023] [Accepted: 05/26/2023] [Indexed: 06/25/2023]
Abstract
The gut microbiome is complex, raising questions about the role of individual strains in the community. Here, we address this question by constructing variants of a complex defined community in which we eliminate strains that occupy the bile acid 7α-dehydroxylation niche. Omitting Clostridium scindens (Cs) and Clostridium hylemonae (Ch) eliminates secondary bile acid production and reshapes the community in a highly specific manner: eight strains change in relative abundance by >100-fold. In single-strain dropout communities, Cs and Ch reach the same relative abundance and dehydroxylate bile acids to a similar extent. However, Clostridium sporogenes increases >1,000-fold in the ΔCs but not ΔCh dropout, reshaping the pool of microbiome-derived phenylalanine metabolites. Thus, strains that are functionally redundant within a niche can have widely varying impacts outside the niche, and a strain swap can ripple through the community in an unpredictable manner, resulting in a large impact on an unrelated community-level phenotype.
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Affiliation(s)
- Min Wang
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305, USA; ChEM-H Institute, Stanford University, Stanford, CA 94305, USA
| | - Lucas J Osborn
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44195, USA; Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Sunit Jain
- ChEM-H Institute, Stanford University, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Xiandong Meng
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305, USA; ChEM-H Institute, Stanford University, Stanford, CA 94305, USA
| | - Allison Weakley
- ChEM-H Institute, Stanford University, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Jia Yan
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - William J Massey
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44195, USA; Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Venkateshwari Varadharajan
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44195, USA; Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Anthony Horak
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44195, USA; Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Rakhee Banerjee
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44195, USA; Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Daniela S Allende
- Department of Anatomical Pathology, Cleveland Clinic, Cleveland, OH 44195, USA
| | - E Ricky Chan
- Institute for Computational Biology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Adeline M Hajjar
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44195, USA; Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Zeneng Wang
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44195, USA; Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Alejandra Dimas
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305, USA; ChEM-H Institute, Stanford University, Stanford, CA 94305, USA
| | - Aishan Zhao
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305, USA; ChEM-H Institute, Stanford University, Stanford, CA 94305, USA
| | - Kazuki Nagashima
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305, USA; ChEM-H Institute, Stanford University, Stanford, CA 94305, USA
| | - Alice G Cheng
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305, USA; ChEM-H Institute, Stanford University, Stanford, CA 94305, USA
| | - Steven Higginbottom
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305, USA; ChEM-H Institute, Stanford University, Stanford, CA 94305, USA
| | - Stanley L Hazen
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44195, USA; Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - J Mark Brown
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44195, USA; Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Michael A Fischbach
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305, USA; ChEM-H Institute, Stanford University, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
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5
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Zhu Y, Dwidar M, Nemet I, Buffa JA, Sangwan N, Li XS, Anderson JT, Romano KA, Fu X, Funabashi M, Wang Z, Keranahalli P, Battle S, Tittle AN, Hajjar AM, Gogonea V, Fischbach MA, DiDonato JA, Hazen SL. Two distinct gut microbial pathways contribute to meta-organismal production of phenylacetylglutamine with links to cardiovascular disease. Cell Host Microbe 2023; 31:18-32.e9. [PMID: 36549300 PMCID: PMC9839529 DOI: 10.1016/j.chom.2022.11.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 09/22/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022]
Abstract
Recent studies show gut microbiota-dependent metabolism of dietary phenylalanine into phenylacetic acid (PAA) is critical in phenylacetylglutamine (PAGln) production, a metabolite linked to atherosclerotic cardiovascular disease (ASCVD). Accordingly, microbial enzymes involved in this transformation are of interest. Using genetic manipulation in selected microbes and monocolonization experiments in gnotobiotic mice, we identify two distinct gut microbial pathways for PAA formation; one is catalyzed by phenylpyruvate:ferredoxin oxidoreductase (PPFOR) and the other by phenylpyruvate decarboxylase (PPDC). PPFOR and PPDC play key roles in gut bacterial PAA production via oxidative and non-oxidative phenylpyruvate decarboxylation, respectively. Metagenomic analyses revealed a significantly higher abundance of both pathways in gut microbiomes of ASCVD patients compared with controls. The present studies show a role for these two divergent microbial catalytic strategies in the meta-organismal production of PAGln. Given the numerous links between PAGln and ASCVD, these findings will assist future efforts to therapeutically target PAGln formation in vivo.
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Affiliation(s)
- Yijun Zhu
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH, USA
| | - Mohammed Dwidar
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH, USA
| | - Ina Nemet
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH, USA
| | - Jennifer A Buffa
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH, USA
| | - Naseer Sangwan
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH, USA
| | - Xinmin S Li
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH, USA
| | - James T Anderson
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH, USA
| | - Kymberleigh A Romano
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH, USA
| | - Xiaoming Fu
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH, USA
| | - Masanori Funabashi
- Department of Bioengineering and ChEM-H, Stanford University, Stanford, CA, USA
| | - Zeneng Wang
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH, USA
| | - Pooja Keranahalli
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Case Western Reserve University, College of Arts and Sciences, Cleveland, OH, USA
| | - Shawna Battle
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Aaron N Tittle
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH, USA
| | - Adeline M Hajjar
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH, USA
| | - Valentin Gogonea
- Department of Chemistry, Cleveland State University, Cleveland, OH, USA
| | - Michael A Fischbach
- Department of Bioengineering and ChEM-H, Stanford University, Stanford, CA, USA
| | - Joseph A DiDonato
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH, USA
| | - Stanley L Hazen
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH, USA; Department of Cardiovascular Medicine, Heart, Vascular and Thoracic Institute, Cleveland Clinic, Cleveland, OH, USA.
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6
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Kantrong N, Chang AM, Bamashmous S, Hajjar AM, Bucala RJ, Darveau RP. Macrophage migration inhibitory factor regulates specific innate immune sensor responses in gingival epithelial cells. J Periodontol 2022; 93:1940-1950. [PMID: 35100435 DOI: 10.1002/jper.21-0598] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/11/2022] [Accepted: 01/21/2022] [Indexed: 01/05/2023]
Abstract
BACKGROUND The gingival epithelium protects periodontal tissues and the alveolar bone by maintaining a steady state of regulated inflammatory surveillance, also known as healthy homeostasis. Accordingly, the repertoire of receptors present within the gingival epithelium showcases its ability to recognize microbial colonization and contribute to bacterial sensing. Macrophage migration inhibitory factor (MIF) is one of many cytokines that are expressed in this protective state and is involved in neutrophil regulation. However, its role in the maintenance of healthy gingival tissue has not been described. METHODS Gingival tissues from wild-type (WT) and Mif knock-out (KO) mice were stained for neutrophils and three key neutrophil chemoattractants: MIF, Gro-α/CXCL1, and Gro-β/CXCL2 in the junctional epithelium (JE). In addition, gene silencing studies were performed using gingival epithelial cells (GECs) to examine the role of MIF on transcription of key bacterial recognition receptors Toll-like receptors (TLR)-1, -2, -4, -6, -9 and interleukin-1 receptors (IL-1R1 and IL-1R2) in response to oral bacterial stimulation. RESULTS WT murine gingival tissues demonstrated high expression of MIF in the JE. In Mif KO mice, despite the significant reduction of Gro-α/CXCL1 and Gro-β/CXCL2, there was a slight increase in neutrophils. Gene silencing experiments showed that MIF down-regulated the mRNA expression of TLR4, IL-1R1, and IL-1R2 in GEC, in addition to decreasing secreted IL-8/CXCL8 in response to bacteria. CONCLUSIONS MIF regulates the expression of TLR4, IL-1Rs, and IL-8/CXCL8, components that are all involved in maintaining oral health. Our data demonstrate that MIF is a significant contributor to the maintenance of healthy oral homeostasis.
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Affiliation(s)
- Nutthapong Kantrong
- Department of Periodontics, University of Washington School of Dentistry, Seattle, Washington, USA.,Department of Oral Health Sciences, University of Washington School of Dentistry, Seattle, Washington, USA.,Oral Biology Research Unit, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - Ana M Chang
- Department of Periodontics, University of Washington School of Dentistry, Seattle, Washington, USA.,Department of Oral Health Sciences, University of Washington School of Dentistry, Seattle, Washington, USA
| | - Shatha Bamashmous
- Department of Periodontics, University of Washington School of Dentistry, Seattle, Washington, USA.,Department of Oral Health Sciences, University of Washington School of Dentistry, Seattle, Washington, USA.,Department of Periodontology, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Adeline M Hajjar
- Department of Comparative Medicine, University of Washington School of Medicine, Seattle, Washington, USA.,Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Richard J Bucala
- Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Richard P Darveau
- Department of Periodontics, University of Washington School of Dentistry, Seattle, Washington, USA.,Department of Oral Health Sciences, University of Washington School of Dentistry, Seattle, Washington, USA.,Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
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7
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Osborn LJ, Schultz K, Massey W, DeLucia B, Choucair I, Varadharajan V, Banerjee R, Fung K, Horak AJ, Orabi D, Nemet I, Nagy LE, Wang Z, Allende DS, Willard BB, Sangwan N, Hajjar AM, McDonald C, Ahern PP, Hazen SL, Brown JM, Claesen J. A gut microbial metabolite of dietary polyphenols reverses obesity-driven hepatic steatosis. Proc Natl Acad Sci U S A 2022; 119:e2202934119. [PMID: 36417437 PMCID: PMC9860326 DOI: 10.1073/pnas.2202934119] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 10/13/2022] [Indexed: 11/24/2022] Open
Abstract
The molecular mechanisms by which dietary fruits and vegetables confer cardiometabolic benefits remain poorly understood. Historically, these beneficial properties have been attributed to the antioxidant activity of flavonoids. Here, we reveal that the host metabolic benefits associated with flavonoid consumption hinge, in part, on gut microbial metabolism. Specifically, we show that a single gut microbial flavonoid catabolite, 4-hydroxyphenylacetic acid (4-HPAA), is sufficient to reduce diet-induced cardiometabolic disease (CMD) burden in mice. The addition of flavonoids to a high fat diet heightened the levels of 4-HPAA within the portal plasma and attenuated obesity, and continuous delivery of 4-HPAA was sufficient to reverse hepatic steatosis. The antisteatotic effect was shown to be associated with the activation of AMP-activated protein kinase α (AMPKα). In a large survey of healthy human gut metagenomes, just over one percent contained homologs of all four characterized bacterial genes required to catabolize flavonols into 4-HPAA. Our results demonstrate the gut microbial contribution to the metabolic benefits associated with flavonoid consumption and underscore the rarity of this process in human gut microbial communities.
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Affiliation(s)
- Lucas J. Osborn
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH44195
| | - Karlee Schultz
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- College of Arts and Sciences, John Carroll University, University Heights, OH44118
| | - William Massey
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH44195
| | - Beckey DeLucia
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
| | - Ibrahim Choucair
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
| | - Venkateshwari Varadharajan
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
| | - Rakhee Banerjee
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
| | - Kevin Fung
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
| | - Anthony J. Horak
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
| | - Danny Orabi
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH44195
- Department of General Surgery, Cleveland Clinic, Cleveland, OH44195
| | - Ina Nemet
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
| | - Laura E. Nagy
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH44195
- Department of Inflammation and Immunity, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
| | - Zeneng Wang
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
| | - Daniela S. Allende
- Robert J. Tomsich Pathology and Laboratory Medicine Institute of the Cleveland Clinic, Cleveland, OH44195
| | - Belinda B. Willard
- Mass Spectrometry Core, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
| | - Naseer Sangwan
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
| | - Adeline M. Hajjar
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
| | - Christine McDonald
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH44195
- Department of Inflammation and Immunity, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
| | - Philip P. Ahern
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH44195
| | - Stanley L. Hazen
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Department of Cardiovascular Medicine, Heart Vascular, and Thoracic Institute Cleveland Clinic, Cleveland, OH44195
| | - J. Mark Brown
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH44195
| | - Jan Claesen
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Center for Microbiome and Human Health, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH44195
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH44195
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8
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Zhu W, Romano KA, Li L, Buffa JA, Sangwan N, Prakash P, Tittle AN, Li XS, Fu X, Androjna C, DiDonato AJ, Brinson K, Trapp BD, Fischbach MA, Rey FE, Hajjar AM, DiDonato JA, Hazen SL. Gut microbes impact stroke severity via the trimethylamine N-oxide pathway. Cell Host Microbe 2021; 29:1199-1208.e5. [PMID: 34139173 DOI: 10.1016/j.chom.2021.05.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/12/2021] [Accepted: 05/11/2021] [Indexed: 12/12/2022]
Abstract
Clinical studies have demonstrated associations between circulating levels of the gut-microbiota-derived metabolite trimethylamine-N-oxide (TMAO) and stroke incident risk. However, a causal role of gut microbes in stroke has not yet been demonstrated. Herein we show that gut microbes, through dietary choline and TMAO generation, directly impact cerebral infarct size and adverse outcomes following stroke. Fecal microbial transplantation from low- versus high-TMAO-producing human subjects into germ-free mice shows that both TMAO generation and stroke severity are transmissible traits. Furthermore, employing multiple murine stroke models and transplantation of defined microbial communities with genetically engineered human commensals into germ-free mice, we demonstrate that the microbial cutC gene (an enzymatic source of choline-to-TMA transformation) is sufficient to transmit TMA/TMAO production, heighten cerebral infarct size, and lead to functional impairment. We thus reveal that gut microbiota in general, specifically the metaorganismal TMAO pathway, directly contributes to stroke severity.
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Affiliation(s)
- Weifei Zhu
- Department of Cardiovascular & Metabolic Sciences, Cleveland Clinic, Cleveland, OH 44195, USA.
| | - Kymberleigh A Romano
- Department of Cardiovascular & Metabolic Sciences, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Lin Li
- Department of Cardiovascular & Metabolic Sciences, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Jennifer A Buffa
- Department of Cardiovascular & Metabolic Sciences, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Naseer Sangwan
- Department of Cardiovascular & Metabolic Sciences, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Prem Prakash
- Department of Cardiovascular & Metabolic Sciences, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Aaron N Tittle
- Department of Cardiovascular & Metabolic Sciences, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Xinmin S Li
- Department of Cardiovascular & Metabolic Sciences, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Xiaoming Fu
- Department of Cardiovascular & Metabolic Sciences, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Charlie Androjna
- Department of Biomedical Engineering, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Anthony J DiDonato
- Department of Cardiovascular & Metabolic Sciences, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Kimberly Brinson
- Department of Cardiovascular & Metabolic Sciences, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Bruce D Trapp
- Department of Neurosciences, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Michael A Fischbach
- Department of Bioengineering and ChEM-H, Stanford University, Stanford, CA, USA
| | - Federico E Rey
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA
| | - Adeline M Hajjar
- Department of Cardiovascular & Metabolic Sciences, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Joseph A DiDonato
- Department of Cardiovascular & Metabolic Sciences, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Stanley L Hazen
- Department of Cardiovascular & Metabolic Sciences, Cleveland Clinic, Cleveland, OH 44195, USA; Cardiovascular Medicine, Heart, Vascular and Thoracic Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
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9
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Nair N, Guedes MS, Hajjar AM, Werts C, Gomes-Solecki M. Role of TLR4 in Persistent Leptospira interrogans Infection: A Comparative In Vivo Study in Mice. Front Immunol 2021; 11:572999. [PMID: 33519799 PMCID: PMC7843520 DOI: 10.3389/fimmu.2020.572999] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 11/30/2020] [Indexed: 12/13/2022] Open
Abstract
Toll-Like Receptor (TLR) 4, the LPS receptor, plays a central role in the control of leptospirosis and absence of TLR4 results in lethal infection in mice. Because human TLR4 does not sense the atypical leptospiral-LPS, we hypothesized that TLR4/MD-2 humanized transgenic mice (huTLR4) may be more susceptible to leptospirosis than wild-type mice, and thus may constitute a model of acute human leptospirosis. We infected huTLR4 mice, which express human TLR4 but not murine TLR4, with a high dose of L. interrogans serovar Copenhageni FioCruz (Leptospira) in comparison to C57BL/6J wild-type (WT) and, as a control, a congenic strain in which the tlr4 coding sequences are deleted (muTLR4Lps-del). We show that the huTLR4 gene is fully functional in the murine background. We found that dissemination of Leptospira in blood, shedding in urine, colonization of the kidney and overall kinetics of leptospirosis progression is equivalent between WT and huTLR4 C57BL/6J mice. Furthermore, inflammation of the kidney appeared to be subdued in huTLR4 compared to WT mice in that we observed less infiltrates of mononuclear lymphocytes, less innate immune markers and no relevant differences in fibrosis markers. Thus, huTLR4 mice showed less inflammation and kidney pathology, and are not more susceptible to leptospirosis than WT mice. This study is significant as it indicates that one intact TLR4 gene, be it mouse or human, is necessary to control acute leptospirosis.
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Affiliation(s)
- Nisha Nair
- Department of Microbiology, Immunology and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Mariana S. Guedes
- Department of Microbiology, Immunology and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Adeline M. Hajjar
- Department of Comparative Medicine, University of Washington, Seattle, WA, United States
| | - Catherine Werts
- Institut Pasteur, Biology and Genetics of the Bacterial Cell Wall Unit, Paris, France,CNRS, UMR 2001 Microbiologie intégrative et Moléculaire, Paris, France
| | - Maria Gomes-Solecki
- Department of Microbiology, Immunology and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN, United States,*Correspondence: Maria Gomes-Solecki,
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10
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Meeker SM, Mears KS, Sangwan N, Brittnacher MJ, Weiss EJ, Treuting PM, Tolley N, Pope CE, Hager KR, Vo AT, Paik J, Frevert CW, Hayden HS, Hoffman LR, Miller SI, Hajjar AM. CFTR dysregulation drives active selection of the gut microbiome. PLoS Pathog 2020; 16:e1008251. [PMID: 31961914 PMCID: PMC6994172 DOI: 10.1371/journal.ppat.1008251] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 01/31/2020] [Accepted: 12/05/2019] [Indexed: 12/30/2022] Open
Abstract
Patients with cystic fibrosis (CF) have altered fecal microbiomes compared to those of healthy controls. The magnitude of this dysbiosis correlates with measures of CF gastrointestinal (GI) disease, including GI inflammation and nutrient malabsorption. However, whether this dysbiosis is caused by mutations in the CFTR gene, the underlying defect in CF, or whether CF-associated dysbiosis augments GI disease was not clear. To test the relationships between CFTR dysfunction, microbes, and intestinal health, we established a germ-free (GF) CF mouse model and demonstrated that CFTR gene mutations are sufficient to alter the GI microbiome. Furthermore, flow cytometric analysis demonstrated that colonized CF mice have increased mesenteric lymph node and spleen TH17+ cells compared with non-CF mice, suggesting that CFTR defects alter adaptive immune responses. Our findings demonstrate that CFTR mutations modulate both the host adaptive immune response and the intestinal microbiome. It has been difficult to establish causal relationships between host genetics and the selection of the vast multitude of micro-organisms that live in and on us (i.e. the microbiota). Cystic fibrosis has been shown to be associated with changes in the fecal microbiome (the genetic constitution of the microbiota) although it was not evident whether mutation of CFTR, the gene mutated in CF, could drive this selection or whether the frequent use of antibiotics in this population was at fault. Here, by using a germfree (i.e. sterile, lacking all microbiota) mouse model of CF we clearly demonstrate that mutated CFTR alone can alter the microbiome. We also show an increase in an adaptive immune cell type (TH17 cells) in the mesenteric lymph nodes and spleens of CF mice compared to control mice. Our study provides new insights into the dominant role that CFTR plays in microbiome determination and suggests that therapies restoring CFTR function could also correct the microbial dysbiosis observed in CF.
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Affiliation(s)
- Stacey M. Meeker
- Department of Comparative Medicine, University of Washington, Seattle, WA, United States of America
| | - Kevin S. Mears
- Department of Comparative Medicine, University of Washington, Seattle, WA, United States of America
| | - Naseer Sangwan
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States of America
| | | | - Eli J. Weiss
- Department of Microbiology, University of Washington, Seattle, WA, United States of America
| | - Piper M. Treuting
- Department of Comparative Medicine, University of Washington, Seattle, WA, United States of America
| | - Nicholas Tolley
- Department of Comparative Medicine, University of Washington, Seattle, WA, United States of America
| | - Christopher E. Pope
- Department Pediatrics, University of Washington, Seattle, WA, United States of America
| | - Kyle R. Hager
- Department of Microbiology, University of Washington, Seattle, WA, United States of America
| | - Anh T. Vo
- Department of Microbiology, University of Washington, Seattle, WA, United States of America
| | - Jisun Paik
- Department of Comparative Medicine, University of Washington, Seattle, WA, United States of America
| | - Charles W. Frevert
- Department of Comparative Medicine, University of Washington, Seattle, WA, United States of America
| | - Hillary S. Hayden
- Department of Microbiology, University of Washington, Seattle, WA, United States of America
| | - Lucas R. Hoffman
- Department of Microbiology, University of Washington, Seattle, WA, United States of America
- Department Pediatrics, University of Washington, Seattle, WA, United States of America
| | - Samuel I. Miller
- Department of Microbiology, University of Washington, Seattle, WA, United States of America
- Departments of Medicine, Allergy and Infectious Disease, and Department of Genome Sciences, University of Washington, Seattle, WA, United States of America
| | - Adeline M. Hajjar
- Department of Comparative Medicine, University of Washington, Seattle, WA, United States of America
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States of America
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States of America
- * E-mail:
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11
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Robison A, Snyder DT, Christensen K, Kimmel E, Hajjar AM, Jutila MA, Hedges JF. Expression of human TLR4/myeloid differentiation factor 2 directs an early innate immune response associated with modest increases in bacterial burden during Coxiella burnetii infection. Innate Immun 2019; 25:401-411. [PMID: 31180798 PMCID: PMC6900644 DOI: 10.1177/1753425919855420] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 04/24/2019] [Accepted: 05/13/2019] [Indexed: 01/25/2023] Open
Abstract
Human TLR4 (hTLR4) and mouse TLR4 molecules respond differently to hypo-acylated LPS. The LPS of Coxiella burnetii is hypo-acylated and heavily glycosylated and causes a minimal response by human cells. Thus, we hypothesized that mice expressing hTLR4 molecules would be more susceptible to C. burnetii infection. Our results show that transgenic mice expressing hTLR4 and the human myeloid differentiation factor 2 (MD-2) adaptor protein (hTLR4/MD-2) respond similarly to wild type mice with respect to overall disease course. However, differences in bacterial burdens in tissues were noted, and lung pathology was increased in hTLR4/MD2 compared to wild type mice. Surprisingly, bone marrow chimera experiments indicated that hTLR4/MD-2 expression on non-hematopoietic cells, rather than the target cells for C. burnetii infection, accounted for increased bacterial burden. Early during infection, cytokines involved in myeloid cell recruitment were detected in the plasma of hTLR4/MD2 mice but not wild type mice. This restricted cytokine response was accompanied by neutrophil recruitment to the lung in hTLR4/MD2 mice. These data suggest that hTLR4/MD-2 alters early responses during C. burnetii infection. These early responses are precursors to later increased bacterial burdens and exacerbated pathology in the lung. Our data suggest an unexpected role for hTLR4/MD-2 in non-hematopoietic cells during C. burnetii infection.
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Affiliation(s)
- Amanda Robison
- Department of Microbiology and Immunology, Montana State University, USA
| | - Deann T Snyder
- Department of Microbiology and Immunology, Montana State University, USA
| | - Kelly Christensen
- Department of Microbiology and Immunology, Montana State University, USA
| | - Emily Kimmel
- Department of Microbiology and Immunology, Montana State University, USA
| | - Adeline M Hajjar
- Department of Comparative Medicine, School of Medicine, University of Washington, USA
| | - Mark A Jutila
- Department of Microbiology and Immunology, Montana State University, USA
| | - Jodi F Hedges
- Department of Microbiology and Immunology, Montana State University, USA
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12
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Chang AM, Liu Q, Hajjar AM, Greer A, McLean JS, Darveau RP. Toll-like receptor-2 and -4 responses regulate neutrophil infiltration into the junctional epithelium and significantly contribute to the composition of the oral microbiota. J Periodontol 2019; 90:1202-1212. [PMID: 31111967 DOI: 10.1002/jper.18-0719] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 01/27/2019] [Accepted: 02/20/2019] [Indexed: 12/15/2022]
Abstract
BACKGROUND Oral gingival tissue, especially the junctional epithelium (JE), is constantly exposed to sub-gingival plaque. A key component of gingival health is the regulation of the number of neutrophils that migrate into the gingival crevice to counteract its harmful effects. This report investigates the contribution of innate defense receptors, Toll-like receptor (TLR)2, TLR4, and both (TLR2/4) to the maintenance of neutrophil homeostasis in the JE. METHODS Bacterial composition was analyzed from whole oral swabs collected from 12- to 14-week-old TLR2, TLR4, TLR2/4 double knock-out (KO) mice using a MiSeq platform targeting the V3-V4 region of the 16S ribosomal RNA gene. Mandibles were histologically examined for quantification of neutrophils in the JE and bone loss. Lastly, total bacterial load was quantitated using quantitative real-time PCR. RESULTS Compared with wild-type, all TLR KO mice displayed significantly increased recruitment of neutrophils (P = 0.0079) into the JE. In addition, TLR4 and TLR2/4 KO mice demonstrated a significant increase in the number of bacteria (P = 0.0022 and P = 0.0152, respectively). Lastly, comparative compositional analyses of the oral microbiome revealed that each KO strain harbored unique microbial communities that are distinct from each other but maintained similar levels of alveolar bone. CONCLUSIONS Neutrophil migration into healthy mouse JE does not require TLR2 or TLR4. However, a significant increase in the number of neutrophils as well as a significant change in the oral microbial composition in both TLR2 and TLR4 KO mice demonstrate that these TLRs contribute to the homeostatic relationship between bacteria and the host in healthy mice periodontal tissue.
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Affiliation(s)
- Ana M Chang
- Department of Oral Health Sciences, University of Washington School of Dentistry, Seattle, WA
| | - Quanhui Liu
- Department of Periodontics, University of Washington School of Dentistry, Seattle, WA
| | - Adeline M Hajjar
- Department of Comparative Medicine, University of Washington School of Medicine, Seattle, WA
| | - Ara Greer
- Department of Oral Health Sciences, University of Washington School of Dentistry, Seattle, WA
| | - Jeffrey S McLean
- Department of Periodontics, University of Washington School of Dentistry, Seattle, WA
| | - Richard P Darveau
- Department of Periodontics, University of Washington School of Dentistry, Seattle, WA
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13
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Hedges JF, Robison A, Snyder DT, Hajjar AM, Jutila MA. Expression of human TLR4/MD-2 directs an early innate immune response associated with modest increase in bacterial burden during Coxiella burnetii infection. The Journal of Immunology 2019. [DOI: 10.4049/jimmunol.202.supp.127.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Human and mouse TLR4 molecules respond differently to hypo-acylated LPS. The LPS of Coxiella burnetii is hypo-acylated, heavily glycosylated and known to cause a minimal response by human cells. We hypothesized that mice expressing hTLR4 molecules would be more susceptible to C. burnetii infection. Our results suggested that transgenic mice expressing hTLR4 and the human MD-2 adaptor protein (hTLR4/MD-2) generally respond similarly to wild type mice, contrary to our hypothesis. Small differences in bacterial burdens in spleens and/or lungs of infected mice were noted and lung pathology was increased in hTLR4/MD2 compared to wild type mice. Surprisingly, bone marrow chimera experiments indicated that hTLR4/MD-2 expression on non-hematopoietic cells, rather than the target cells for C. burnetii infection, accounted for increased bacterial burden. Very early during infection, cytokines involved in myeloid cell recruitment were detected in the plasma of hTLR4/MD2 mice, but not in wild type mice. This restricted cytokine response was accompanied by early neutrophil recruitment to the lung in hTLR4/MD2 mice. These data suggest that hTLR4/MD-2 may alter early responses to C. burnetii infection. Our results suggest that during C. burnetii infection, the species of origin for TLR4 may be less important than with other pathogens with hypoacylated LPS.
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14
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Affiliation(s)
- Lucas R. Hoffman
- Department of Pediatrics
- Department of MicrobiologyUniversity of WashingtonSeattle, Washingtonand
| | - Adeline M. Hajjar
- Department of Comparative MedicineUniversity of WashingtonSeattle, Washington
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15
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Marshall JD, Heeke DS, Rao E, Maynard SK, Hornigold D, McCrae C, Fraser N, Tovchigrechko A, Yu L, Williams N, King S, Cooper ME, Hajjar AM, Woo JC. A Novel Class of Small Molecule Agonists with Preference for Human over Mouse TLR4 Activation. PLoS One 2016; 11:e0164632. [PMID: 27736941 PMCID: PMC5063506 DOI: 10.1371/journal.pone.0164632] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 09/28/2016] [Indexed: 01/09/2023] Open
Abstract
The best-characterized Toll-like receptor 4 (TLR4) ligands are lipopolysaccharide (LPS) and its chemically modified and detoxified variant, monophosphoryl lipid A (MPL). Although both molecules are active for human TLR4, they demonstrate a potency preference for mouse TLR4 based on data from transfected cell lines and primary cells of both species. After a high throughput screening process of small molecule libraries, we have discovered a new class of TLR4 agonist with a species preference profile differing from MPL. Products of the 4-component Ugi synthesis reaction were demonstrated to potently trigger human TLR4-transfected HEK cells but not mouse TLR4, although inclusion of the human MD2 with mTLR4 was able to partially recover activity. Co-expression of CD14 was not required for optimal activity of Ugi compounds on transfected cells, as it is for LPS. The species preference profile for the panel of Ugi compounds was found to be strongly active for human and cynomolgus monkey primary cells, with reduced but still substantial activity for most Ugi compounds on guinea pig cells. Mouse, rat, rabbit, ferret, and cotton rat cells displayed little or no activity when exposed to Ugi compounds. However, engineering the human versions of TLR4 and MD2 to be expressed in mTLR4/MD2 deficient mice allowed for robust activity by Ugi compounds both in vitro and in vivo. These findings extend the range of compounds available for development as agonists of TLR4 and identify novel molecules which reverse the TLR4 triggering preference of MPL for mouse TLR4 over human TLR4. Such compounds may be amenable to formulation as more potent human-specific TLR4L-based adjuvants than typical MPL-based adjuvants.
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Affiliation(s)
- Jason D. Marshall
- Vaccine Platform Group, MedImmune, Gaithersburg, Maryland, United States of America
- * E-mail:
| | - Darren S. Heeke
- Translational Biology Group, MedImmune, Mountain View, California, United States of America
| | - Eileen Rao
- Translational Biology Group, MedImmune, Mountain View, California, United States of America
| | - Sean K. Maynard
- Vaccine Platform Group, MedImmune, Gaithersburg, Maryland, United States of America
| | - David Hornigold
- Department of Cardiovascular and Metabolic Diseases, MedImmune, Cambridge, United Kingdom
| | - Christopher McCrae
- Translational Science, Respiratory, Inflammation and Autoimmunity Innovative Medicines, AstraZeneca R&D, Mölndal, Sweden
| | - Neil Fraser
- Biology Department, AstraZeneca R&D, Charnwood, United Kingdom
| | - Andrey Tovchigrechko
- Research Bioinformatics, MedImmune, Gaithersburg, Maryland, United States of America
| | - Li Yu
- Statistical Sciences, MedImmune, Gaithersburg, Maryland, United States of America
| | - Nicola Williams
- Biology Department, AstraZeneca R&D, Charnwood, United Kingdom
| | - Sarah King
- Medicinal Chemistry Department, AstraZeneca R&D, Charnwood, United Kingdom
| | - Martin E. Cooper
- Translational Science, Respiratory, Inflammation and Autoimmunity Innovative Medicines, AstraZeneca R&D, Mölndal, Sweden
| | - Adeline M. Hajjar
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
| | - Jennifer C. Woo
- Translational Biology Group, MedImmune, Mountain View, California, United States of America
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16
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Ernst RK, Hajjar AM, Tsai JH, Moskowitz SM, Wilson CB, Miller SI. Pseudomonas aeruginosa lipid A diversity and its recognition by Toll-like receptor 4. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/09680519030090060201] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Lipid A is the pro-inflammatory component of bacterial lipopolysaccharide, the major surface component of Gram-negative bacteria. Gram-negative bacteria alter the structure of lipid A in response to specific environmental conditions including those found upon colonization of a host. The opportunistic pathogen Pseudomonas aeruginosa synthesizes a unique hexa-acylated lipid A containing palmitate and aminoarabinose during adaptation to the cystic fibrosis airway. Different lipid A species are observed in P. aeruginosa isolated from non-cystic fibrosis associated infections. Here we report that P. aeruginosa isolates from the airway of a cystic fibrosis patient with severe pulmonary disease synthesized a novel hepta-acylated lipid A. Cystic fibrosis-specific P. aeruginosa lipid A modifications result in resistance to host antimicrobial peptides and increased recognition by human Toll-like receptor 4 (TLR4). Using P. aeruginosa lipid A with different levels of acylation, we identified a 222 amino acid region in the extracellular portion of human TLR4 that is required for the differential recognition of cystic fibrosis-specific lipid A. P. aeruginosa adaptation to the human airway may, therefore, play a fundamental role in the progressive lung damage associated with cystic fibrosis.
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Affiliation(s)
- Robert K. Ernst
- Department of Medicine, University of Washington, Seattle, Washington, USA,
| | - Adeline M. Hajjar
- Department of Immunology, University of Washington, Seattle, Washington, USA
| | - Jeff H. Tsai
- Department of Immunology, University of Washington, Seattle, Washington, USA
| | - Samuel M. Moskowitz
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Christopher B. Wilson
- Department of Immunology, University of Washington, Seattle, Washington, USA, Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Samuel I. Miller
- Department of Medicine, University of Washington, Seattle, Washington, USA, Department of Genome Sciences, University of Washington, Seattle, Washington, USA, Department of Microbiology, University of Washington, Seattle, Washington, USA
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17
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Robison A, Hedges JF, Kimmel E, Hajjar AM, Jutila MA. Expression of human hTLR4/MD2 in vivo in mice alters infection with C. burnetii. The Journal of Immunology 2016. [DOI: 10.4049/jimmunol.196.supp.66.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Human and mouse TLR4/MD2 molecules respond differently to specific types of LPS. Their response to normally acylated LPS is similar, but they respond differently to hypoacylated LPS found on specific gram-negative bacteria. The LPS of Coxiella burnetii is hypoacylated, heavily glycosylated and is known to cause a minimal response by human cells. We hypothesized that mice expressing human TLR4/MD2 (hTLR4/MD2) molecules would respond differently to C. burnetii infection compared to wild type mice. Mice expressing hTLR4/MD2 molecules had enhanced weight loss, and more bacteria in tissues than did wild-type mice. Bone marrow chimera experiments indicated that mice expressing hTLR4/MD2 on stromal/epithelia cells had more severe disease and enhanced bacterial replication compared to when mouse TLR4 was expressed on these cells. Surprisingly, hTLR4 expression on hematopoietic cells was of minimal consequence. These data suggest that species-specific TLR4/MD2 responses in stromal and epithelial compartments can alter the disease course. Studying C. burnetii infection in hTLR4/MD2-expressing mice will result in findings that are likely more readily applicable to human patients.
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18
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Paik J, Pershutkina O, Meeker S, Yi JJ, Dowling S, Hsu C, Hajjar AM, Maggio-Price L, Beck DAC. Potential for using a hermetically-sealed, positive-pressured isocage system for studies involving germ-free mice outside a flexible-film isolator. Gut Microbes 2015; 6:255-65. [PMID: 26177210 PMCID: PMC4615381 DOI: 10.1080/19490976.2015.1064576] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Germ-free mice are used to examine questions about the role of the gut microbiota in development of diseases. Generally these animals are maintained in semi-rigid or flexible-film isolators to ensure their continued sterility or, if colonized with specific microbiota, to ensure that no new species are introduced. Here, we describe the use of a caging system in which individual cages are hermetically sealed and have their own filtered positive airflow. This isopositive caging system requires less space and reduces animal housing costs. By using strict sterile techniques, we kept mice germ-free in this caging system for 12 weeks. We also used this caging system and approach to conduct studies evaluating a) the stability of the microbiome in germ-free mice receiving a fecal transplant and b) the stability of dietary-induced microbiota changes in fecal-transplanted mice. As has been shown in fecal transfer studies in isolators, we found that the transferred microbiota stabilizes as early as 2 weeks post transfer although recipient microbiota did not completely recapitulate those of the donors. Interestingly, we also noted some sex effects in these studies indicating that the sex of recipients or donors may play a role in colonization of microbiota. However, a larger study will be needed to determine what role, if any, sex plays in colonization of microbiota. Based on our studies, an isopositive caging system may be utilized to test multiple donor samples for their effects on phenotypes of mice in both normal and disease states even with limited available space for housing.
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Affiliation(s)
- Jisun Paik
- The Department of Comparative Medicine; University of Washington; Seattle, WA USA,Correspondence to: Jisun Paik;
| | - Olesya Pershutkina
- The Department of Comparative Medicine; University of Washington; Seattle, WA USA
| | - Stacey Meeker
- The Department of Comparative Medicine; University of Washington; Seattle, WA USA
| | - Jaehun J Yi
- The Department of Comparative Medicine; University of Washington; Seattle, WA USA
| | - Susan Dowling
- The Department of Comparative Medicine; University of Washington; Seattle, WA USA
| | - Charlie Hsu
- The Department of Comparative Medicine; University of Washington; Seattle, WA USA
| | - Adeline M Hajjar
- The Department of Comparative Medicine; University of Washington; Seattle, WA USA
| | - Lillian Maggio-Price
- The Department of Comparative Medicine; University of Washington; Seattle, WA USA
| | - David A C Beck
- Department of Chemical Engineering; University of Washington; Seattle, WA USA,eScience Institute; University of Washington; Seattle, WA USA
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19
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Maeshima N, Evans-Atkinson T, Hajjar AM, Fernandez RC. Bordetella pertussis Lipid A Recognition by Toll-like Receptor 4 and MD-2 Is Dependent on Distinct Charged and Uncharged Interfaces. J Biol Chem 2015; 290:13440-53. [PMID: 25837248 DOI: 10.1074/jbc.m115.653881] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2015] [Indexed: 12/22/2022] Open
Abstract
Lipid A in LPS activates innate immunity through the Toll-like receptor 4 (TLR4)-MD-2 complex on host cells. Variation in lipid A has significant consequences for TLR4 activation and thus may be a means by which Gram-negative bacteria modulate host immunity. However, although even minor changes in lipid A structure have been shown to affect downstream immune responses, the mechanism by which the TLR4-MD-2 receptor complex recognizes these changes is not well understood. We previously showed that strain BP338 of the human pathogen Bordetella pertussis, the causative agent of whooping cough, modifies its lipid A by the addition of glucosamine moieties that promote TLR4 activation in human, but not mouse, macrophages. Using site-directed mutagenesis and an NFκB reporter assay screen, we have identified several charged amino acid residues in TLR4 and MD-2 that are important for these species-specific responses; some of these are novel for responses to penta-acyl B. pertussis LPS, and their mutation does not affect the response to hexa-acylated Escherichia coli LPS or tetra-acylated lipid IVA. We additionally show evidence that suggests that recognition of penta-acylated B. pertussis lipid A is dependent on uncharged amino acids in TLR4 and MD-2 and that this is true for both human and mouse TLR4-MD-2 receptors. Taken together, we have demonstrated that the TLR4-MD-2 receptor complex recognizes variation in lipid A molecules using multiple sites for receptor-ligand interaction and propose that host-specific immunity to a particular Gram-negative bacterium is, at least in part, mediated by very subtle tuning of one of the earliest interactions at the host-pathogen interface.
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Affiliation(s)
- Nina Maeshima
- From the Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3 and
| | - Tara Evans-Atkinson
- From the Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3 and
| | - Adeline M Hajjar
- Department of Comparative Medicine, University of Washington, Seattle, Washington 98195
| | - Rachel C Fernandez
- From the Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3 and
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20
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Loomis WP, Johnson ML, Brasfield A, Blanc MP, Yi J, Miller SI, Cookson BT, Hajjar AM. Temporal and anatomical host resistance to chronic Salmonella infection is quantitatively dictated by Nramp1 and influenced by host genetic background. PLoS One 2014; 9:e111763. [PMID: 25350459 PMCID: PMC4211889 DOI: 10.1371/journal.pone.0111763] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 09/30/2014] [Indexed: 01/09/2023] Open
Abstract
The lysosomal membrane transporter, Nramp1, plays a key role in innate immunity and resistance to infection with intracellular pathogens such as non-typhoidal Salmonella (NTS). NTS-susceptible C57BL/6 (B6) mice, which express the mutant Nramp1D169 allele, are unable to control acute infection with Salmonella enterica serovar Typhimurium following intraperitoneal or oral inoculation. Introducing functional Nramp1G169 into the B6 host background, either by constructing a congenic strain carrying Nramp1G169 from resistant A/J mice (Nramp-Cg) or overexpressing Nramp1G169 from a transgene (Nramp-Tg), conferred equivalent protection against acute Salmonella infection. In contrast, the contributions of Nramp1 for controlling chronic infection are more complex, involving temporal and anatomical differences in Nramp1-dependent host responses. Nramp-Cg, Nramp-Tg and NTS-resistant 129×1/SvJ mice survived oral Salmonella infection equally well for the first 2–3 weeks, providing evidence that Nramp1 contributes to the initial control of NTS bacteremia preceding establishment of chronic Salmonella infection. By day 30, increased host Nramp1 expression (Tg>Cg) provided greater protection as indicated by decreased splenic bacterial colonization (Tg<Cg). However, despite controlling bacterial growth within MLN as effectively as 129×1/SvJ mice, Nramp-Cg and Nramp-Tg mice eventually succumbed to infection. These data indicate: 1) discrete, anatomically localized host resistance is conferred by Nramp1 expression in NTS-susceptible mice, 2) restriction of systemic bacterial growth in the spleens of NTS-susceptible mice is enhanced by Nramp1 expression and dose-dependent, and 3) host genes other than Nramp1 also contribute to the ability of NTS-resistant 129×1/SvJ mice to control bacterial replication during chronic infection.
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Affiliation(s)
- Wendy P. Loomis
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Matthew L. Johnson
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Alicia Brasfield
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
| | - Marie-Pierre Blanc
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Jaehun Yi
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
| | - Samuel I. Miller
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
- Departments of Medicine and Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Brad T. Cookson
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Adeline M. Hajjar
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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21
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West TE, Myers ND, Chantratita N, Chierakul W, Limmathurotsakul D, Wuthiekanun V, Miao EA, Hajjar AM, Peacock SJ, Liggitt HD, Skerrett SJ. NLRC4 and TLR5 each contribute to host defense in respiratory melioidosis. PLoS Negl Trop Dis 2014; 8:e3178. [PMID: 25232720 PMCID: PMC4169243 DOI: 10.1371/journal.pntd.0003178] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 08/09/2014] [Indexed: 02/02/2023] Open
Abstract
Burkholderia pseudomallei causes the tropical infection melioidosis. Pneumonia is a common manifestation of melioidosis and is associated with high mortality. Understanding the key elements of host defense is essential to developing new therapeutics for melioidosis. As a flagellated bacterium encoding type III secretion systems, B. pseudomallei may trigger numerous host pathogen recognition receptors. TLR5 is a flagellin sensor located on the plasma membrane. NLRC4, along with NAIP proteins, assembles a canonical caspase-1-dependent inflammasome in the cytoplasm that responds to flagellin (in mice) and type III secretion system components (in mice and humans). In a murine model of respiratory melioidosis, Tlr5 and Nlrc4 each contributed to survival. Mice deficient in both Tlr5 and Nlrc4 were not more susceptible than single knockout animals. Deficiency of Casp1/Casp11 resulted in impaired bacterial control in the lung and spleen; in the lung much of this effect was attributable to Nlrc4, despite relative preservation of pulmonary IL-1β production in Nlrc4−/− mice. Histologically, deficiency of Casp1/Casp11 imparted more severe pulmonary inflammation than deficiency of Nlrc4. The human NLRC4 region polymorphism rs6757121 was associated with survival in melioidosis patients with pulmonary involvement. Co-inheritance of rs6757121 and a functional TLR5 polymorphism had an additive effect on survival. Our results show that NLRC4 and TLR5, key components of two flagellin sensing pathways, each contribute to host defense in respiratory melioidosis. Melioidosis is an infection caused by Burkholderia pseudomallei, a bacterium that is found in tropical soil and water. Melioidosis can present in a variety of ways, but lung involvement is common and usually severe. The host response to infection governs outcome. In this study, we examined the role of two host sensors of bacterial components–TLR5 and NLRC4–to determine their necessity in respiratory melioidosis. Although both proteins are involved in detection of bacterial flagellin, in mice we defined specific and individual roles for TLR5 and NLRC4 in protecting against death from melioidosis. In humans with melioidosis involving the lung, genetic variation in these receptors also had independent associations with survival. These results underscore the importance of these elements of host defense in respiratory melioidosis and support further studies of the underlying mechanisms.
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Affiliation(s)
- T. Eoin West
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, United States of America
- International Respiratory and Severe Illness Center, University of Washington, Seattle, Washington, United States of America
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- * E-mail:
| | - Nicolle D. Myers
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Narisara Chantratita
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Wirongrong Chierakul
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Direk Limmathurotsakul
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Vanaporn Wuthiekanun
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Edward A. Miao
- Department of Microbiology and Immunology, Lineberger Comprehensive Cancer Center, and Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Adeline M. Hajjar
- Department of Comparative Medicine, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Sharon J. Peacock
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - H. Denny Liggitt
- Department of Comparative Medicine, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Shawn J. Skerrett
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, United States of America
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22
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Snyder JM, Treuting PM, Nagy L, Yam C, Yi J, Brasfield A, Nguyen LPA, Hajjar AM. Humanized TLR7/8 expression drives proliferative multisystemic histiocytosis in C57BL/6 mice. PLoS One 2014; 9:e107257. [PMID: 25229618 PMCID: PMC4168129 DOI: 10.1371/journal.pone.0107257] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 08/11/2014] [Indexed: 02/04/2023] Open
Abstract
A humanized TLR7/TLR8 transgenic mouse line was engineered for studies using TLR7/8 ligands as vaccine adjuvants. The mice developed a spontaneous immune-mediated phenotype prior to six months of age characterized by runting, lethargy, blepharitis, and corneal ulceration. Histological examination revealed a marked, multisystemic histiocytic infiltrate that effaced normal architecture. The histological changes were distinct from those previously reported in mouse models of systemic lupus erythematosus. When the mice were crossed with MyD88-/- mice, which prevented toll-like receptor signaling, the inflammatory phenotype resolved. Illness may be caused by constitutive activation of human TLR7 or TLR8 in the bacterial artificial chromosome positive mice as increased TLR7 and TLR8 expression or activation has previously been implicated in autoimmune disease.
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Affiliation(s)
- Jessica M. Snyder
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
- Comparative Pathology Program, University of Washington, Seattle, Washington, United States of America
| | - Piper M. Treuting
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
- Comparative Pathology Program, University of Washington, Seattle, Washington, United States of America
| | - Lee Nagy
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
| | - Cathy Yam
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
| | - Jaehun Yi
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
| | - Alicia Brasfield
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
| | - Lisa Phuong Anh Nguyen
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
| | - Adeline M. Hajjar
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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23
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Hajjar AM, Ernst RK, Fortuno ES, Brasfield AS, Yam CS, Newlon LA, Kollmann TR, Miller SI, Wilson CB. Humanized TLR4/MD-2 mice reveal LPS recognition differentially impacts susceptibility to Yersinia pestis and Salmonella enterica. PLoS Pathog 2012; 8:e1002963. [PMID: 23071439 PMCID: PMC3469661 DOI: 10.1371/journal.ppat.1002963] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Accepted: 08/23/2012] [Indexed: 02/02/2023] Open
Abstract
Although lipopolysaccharide (LPS) stimulation through the Toll-like receptor (TLR)-4/MD-2 receptor complex activates host defense against Gram-negative bacterial pathogens, how species-specific differences in LPS recognition impact host defense remains undefined. Herein, we establish how temperature dependent shifts in the lipid A of Yersinia pestis LPS that differentially impact recognition by mouse versus human TLR4/MD-2 dictate infection susceptibility. When grown at 37°C, Y. pestis LPS is hypo-acylated and less stimulatory to human compared with murine TLR4/MD-2. By contrast, when grown at reduced temperatures, Y. pestis LPS is more acylated, and stimulates cells equally via human and mouse TLR4/MD-2. To investigate how these temperature dependent shifts in LPS impact infection susceptibility, transgenic mice expressing human rather than mouse TLR4/MD-2 were generated. We found the increased susceptibility to Y. pestis for "humanized" TLR4/MD-2 mice directly paralleled blunted inflammatory cytokine production in response to stimulation with purified LPS. By contrast, for other Gram-negative pathogens with highly acylated lipid A including Salmonella enterica or Escherichia coli, infection susceptibility and the response after stimulation with LPS were indistinguishable between mice expressing human or mouse TLR4/MD-2. Thus, Y. pestis exploits temperature-dependent shifts in LPS acylation to selectively evade recognition by human TLR4/MD-2 uncovered with "humanized" TLR4/MD-2 transgenic mice.
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Affiliation(s)
- Adeline M Hajjar
- Department of Comparative Medicine, University of Washington, Seattle, Washington, USA.
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24
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Awoniyi M, Miller SI, Wilson CB, Hajjar AM, Smith KD. Homeostatic regulation of Salmonella-induced mucosal inflammation and injury by IL-23. PLoS One 2012; 7:e37311. [PMID: 22624013 PMCID: PMC3356277 DOI: 10.1371/journal.pone.0037311] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 04/19/2012] [Indexed: 12/14/2022] Open
Abstract
IL-12 and IL-23 regulate innate and adaptive immunity to microbial pathogens through influencing the expression of IFN-γ, IL-17, and IL-22. Herein we define the roles of IL-12 and IL-23 in regulating host resistance and intestinal inflammation during acute Salmonella infection. We find that IL-23 alone is dispensable for protection against systemic spread of bacteria, but synergizes with IL-12 for optimal protection. IL-12 promotes the production of IFN-γ by NK cells, which is required for resistance against Salmonella and also for induction of intestinal inflammation and epithelial injury. In contrast, IL-23 controls the severity of inflammation by inhibiting IL-12A expression, reducing IFN-γ and preventing excessive mucosal injury. Our studies demonstrate that IL-23 is a homeostatic regulator of IL-12-dependent, IFN-γ-mediated intestinal inflammation.
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Affiliation(s)
- Muyiwa Awoniyi
- Department of Pathology and Program in Molecular and Cellular Biology, University of Washington, Seattle, Washington, United States of America
| | - Samuel I. Miller
- Departments of Medicine, Genome Sciences and Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Christopher B. Wilson
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
| | - Adeline M. Hajjar
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
| | - Kelly D. Smith
- Department of Pathology and Program in Molecular and Cellular Biology, University of Washington, Seattle, Washington, United States of America
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25
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Corbett NP, Blimkie D, Ho KC, Cai B, Sutherland DP, Kallos A, Crabtree J, Rein-Weston A, Lavoie PM, Turvey SE, Hawkins NR, Self SG, Wilson CB, Hajjar AM, Fortuno ES, Kollmann TR. Ontogeny of Toll-like receptor mediated cytokine responses of human blood mononuclear cells. PLoS One 2010; 5:e15041. [PMID: 21152080 PMCID: PMC2994830 DOI: 10.1371/journal.pone.0015041] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Accepted: 10/14/2010] [Indexed: 01/21/2023] Open
Abstract
Newborns and young infants suffer increased infectious morbidity and mortality as compared to older children and adults. Morbidity and mortality due to infection are highest during the first weeks of life, decreasing over several years. Furthermore, most vaccines are not administered around birth, but over the first few years of life. A more complete understanding of the ontogeny of the immune system over the first years of life is thus urgently needed. Here, we applied the most comprehensive analysis focused on the innate immune response following TLR stimulation over the first 2 years of life in the largest such longitudinal cohort studied to-date (35 subjects). We found that innate TLR responses (i) known to support Th17 adaptive immune responses (IL-23, IL-6) peaked around birth and declined over the following 2 years only to increase again by adulthood; (ii) potentially supporting antiviral defense (IFN-α) reached adult level function by 1 year of age; (iii) known to support Th1 type immunity (IL-12p70, IFN-γ) slowly rose from a low at birth but remained far below adult responses even at 2 years of age; (iv) inducing IL-10 production steadily declined from a high around birth to adult levels by 1 or 2 years of age, and; (v) leading to production of TNF-α or IL-1β varied by stimuli. Our data contradict the notion of a linear progression from an ‘immature’ neonatal to a ‘mature’ adult pattern, but instead indicate the existence of qualitative and quantitative age-specific changes in innate immune reactivity in response to TLR stimulation.
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Affiliation(s)
- Nathan P. Corbett
- Division of Infectious and Immunological Diseases, Department of Pediatrics, University of British Columbia, Vancouver, Canada
| | - Darren Blimkie
- Division of Infectious and Immunological Diseases, Department of Pediatrics, University of British Columbia, Vancouver, Canada
| | - Kevin C. Ho
- Division of Infectious and Immunological Diseases, Department of Pediatrics, University of British Columbia, Vancouver, Canada
| | - Bing Cai
- Division of Infectious and Immunological Diseases, Department of Pediatrics, University of British Columbia, Vancouver, Canada
| | - Darren P. Sutherland
- Division of Infectious and Immunological Diseases, Department of Pediatrics, University of British Columbia, Vancouver, Canada
| | - Arlene Kallos
- Division of Infectious and Immunological Diseases, Department of Pediatrics, University of British Columbia, Vancouver, Canada
| | - Juliet Crabtree
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
| | - Annie Rein-Weston
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
| | - Pascal M. Lavoie
- Division of Infectious and Immunological Diseases, Department of Pediatrics, University of British Columbia, Vancouver, Canada
| | - Stuart E. Turvey
- Division of Infectious and Immunological Diseases, Department of Pediatrics, University of British Columbia, Vancouver, Canada
| | - Natalie R. Hawkins
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Steven G. Self
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | | | - Adeline M. Hajjar
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
| | - Edgardo S. Fortuno
- Division of Infectious and Immunological Diseases, Department of Pediatrics, University of British Columbia, Vancouver, Canada
- * E-mail: (TK)
| | - Tobias R. Kollmann
- Division of Infectious and Immunological Diseases, Department of Pediatrics, University of British Columbia, Vancouver, Canada
- * E-mail: (TK)
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Marr N, Novikov A, Hajjar AM, Caroff M, Fernandez RC. Variability in the lipooligosaccharide structure and endotoxicity among Bordetella pertussis strains. J Infect Dis 2010; 202:1897-906. [PMID: 21050116 DOI: 10.1086/657409] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Bordetella endotoxins show remarkable structural variability both among each other and in comparison to other gram-negative bacteria. Here we demonstrate that, in contrast to the common Bordetella pertussis laboratory strain and Tohama I derivative BP338, lipooligosaccharide from mouse challenge strain 18-323 is a poor inducer of inflammatory cytokines in human and murine macrophages, is greatly impaired in Toll-like receptor 4-mediated activation of nuclear factor-κB in transfected HEK-293 cells, and functions as a Toll-like receptor 4 antagonist. Comparison of lipid A and lipooligosaccharide structures of B. pertussis strains BP338 and 18-323 revealed that 18-323 (1) lacks the ability to modify its lipid A phosphate groups with glucosamine, (2) is distinct in its acylation at the C3' position of the lipid A diglucosamine backbone, and (3) expresses molecular lipooligosaccharide species that lack a terminal heptose. Our findings have important implications for interpreting previous studies of host defenses to B. pertussis infection in mice and in vitro.
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Affiliation(s)
- Nico Marr
- Department of Microbiology & Immunology, University of British Columbia, Vancouver, British Columbia, Canada
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Parra MC, Shaffer SA, Hajjar AM, Gallis BM, Hager A, Goodlett DR, Guina T, Miller S, Collins CM. Identification, cloning, expression, and purification of Francisella lpp3: an immunogenic lipoprotein. Microbiol Res 2009; 165:531-45. [PMID: 20006480 DOI: 10.1016/j.micres.2009.11.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Revised: 10/27/2009] [Accepted: 11/07/2009] [Indexed: 12/17/2022]
Abstract
The severe and fatal human disease, tularemia, results from infection with the Gram-negative pathogen Francisella tularensis. Identification of surface outer membrane proteins, specifically lipoproteins, has been of interest for vaccine development and understanding the initiation of disease. We sought to identify Francisella live vaccine strain lipoproteins that could be a component of a subunit vaccine and have adjuvant properties as TLR2 agonists. We have identified a membrane lipoprotein of Francisella LVS isolated by sarkosyl extraction and gel filtration chromatography that is recognized by sera from LVS-vaccinated individuals and tularemia patients, indicating its potential diagnostic value. Sequencing of the protein by mass spectrometry indicated that it encodes the FTL_0645 open reading frame of F. holarctica LVS, which is 100% identical/homologous to FTT1416c of F. tularensis Schu S4. The predicted 137 amino acid lipoprotein encoded by FTL_0645 ORF, was expressed in Escherichia coli, purified, and demonstrated to be a lipoprotein. This recombinant lipoprotein, named Flpp3, was able to activate TLR2 and induce an immunogenic response in mice, suggesting that the E. coli-expressed Flpp3 is palmitoylated and closely resembles the native protein in structure and immunogenicity. Taken together, these data suggest that Flpp3 could be a candidate for inclusion in a F. tularensis vaccine.
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Affiliation(s)
- Maria C Parra
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA; Department of Immunology, University of Washington, Seattle, WA 98195, USA.
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Kollmann TR, Crabtree J, Rein-Weston A, Blimkie D, Thommai F, Wang XY, Lavoie PM, Furlong J, Fortuno ES, Hajjar AM, Hawkins NR, Self SG, Wilson CB. Neonatal innate TLR-mediated responses are distinct from those of adults. J Immunol 2009; 183:7150-60. [PMID: 19917677 DOI: 10.4049/jimmunol.0901481] [Citation(s) in RCA: 344] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The human neonate and infant are unduly susceptible to infection with a wide variety of microbes. This susceptibility is thought to reflect differences from adults in innate and adaptive immunity, but the nature of these differences is incompletely characterized. The innate immune response directs the subsequent adaptive immune response after integrating information from TLRs and other environmental sensors. We set out to provide a comprehensive analysis defining differences in response to TLR ligation between human neonates and adults. In response to most TLR ligands, neonatal innate immune cells, including monocytes and conventional and plasmacytoid dendritic cells produced less IL-12p70 and IFN-alpha (and consequently induced less IFN-gamma), moderately less TNF-alpha, but as much or even more IL-1beta, IL-6, IL-23, and IL-10 than adult cells. At the single-cell level, neonatal innate cells generally were less capable of producing multiple cytokines simultaneously, i.e., were less polyfunctional. Overall, our data suggest a robust if not enhanced capacity of the neonate vs the adult white-blood cell TLR-mediated response to support Th17- and Th2-type immunity, which promotes defense against extracellular pathogens, but a reduced capacity to support Th1-type responses, which promote defense against intracellular pathogens.
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Affiliation(s)
- Tobias R Kollmann
- Division of Infectious and Immunological Diseases, Department of Pediatrics, University of British Columbia, CFRI, 950 West 28th Avenue, Vancouver, BC, V5Z4H4, Canada.
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Aldape MJ, Bryant AE, Katahira EJ, Hajjar AM, Finegold SM, Ma Y, Stevens DL. Innate immune recognition of, and response to, Clostridium sordellii. Anaerobe 2009; 16:125-30. [PMID: 19559804 DOI: 10.1016/j.anaerobe.2009.06.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2009] [Revised: 04/17/2009] [Accepted: 06/16/2009] [Indexed: 02/02/2023]
Abstract
Clostridium sordellii, an anaerobic pathogen, has recently been associated with rapidly fatal infections following medically induced abortions and injecting drug use. Patients with C. sordellii infection display few signs of inflammation such as fever, or redness and pain at the site of infection. We hypothesized that this could be due to reduced recognition of the organism by Toll-like receptors (TLRs) of the innate immune system. An ELAM-NF-kappaB luciferase reporter system in TLR-transfected HEK cells was used to measure TLR-dependent recognition of washed, heat-killed C. sordellii and other pathogenic clostridial species. Results demonstrated that all clostridia were well recognized by TLR2 alone and that responses were greatest when TLR2 was co-expressed with TLR6. Further, isolated human monocytes produced the pro-inflammatory cytokine TNFalpha and the immunoregulator IL-10 in response to C. sordellii. In addition, C. sordellii-stimulated monocytes produced 30% less TNFalpha following treatment with an anti-TLR2 blocking antibody. These data demonstrate that innate immune recognition of, and response to, cell-associated components of C. sordellii and other clostridial pathogens are mediated by TLR2 in combination with TLR6. We conclude that the characteristic absence of inflammatory signs and symptoms in C. sordellii infection is not related to inadequate immune detection of the organism, but rather is attributable to a species-specific immune system dysfunction that remains to be elucidated.
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Affiliation(s)
- M J Aldape
- Veterans Affairs Medical Center, Infectious Diseases Section, Boise, ID 83702, USA.
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Voronina VA, Takemaru KI, Treuting P, Love D, Grubb BR, Hajjar AM, Adams A, Li FQ, Moon RT. Inactivation of Chibby affects function of motile airway cilia. ACTA ACUST UNITED AC 2009; 185:225-33. [PMID: 19364920 PMCID: PMC2700371 DOI: 10.1083/jcb.200809144] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Chibby (Cby) is a conserved component of the Wnt–β-catenin pathway. Cby physically interacts with β-catenin to repress its activation of transcription. To elucidate the function of Cby in vertebrates, we generated Cby−/− mice and found that after 2–3 d of weight loss, the majority of mice die before or around weaning. All Cby−/− mice develop rhinitis and sinusitis. When challenged with Pseudomonas aeruginosa isolates, Cby−/− mice are unable to clear the bacteria from the nasal cavity. Notably, Cby−/− mice exhibit a complete absence of mucociliary transport caused by a marked paucity of motile cilia in the nasal epithelium. Moreover, ultrastructural experiments reveal impaired basal body docking to the apical surface of multiciliated cells. In support of these phenotypes, endogenous Cby protein is localized at the base of cilia. As the phenotypes of Cby−/− mice bear striking similarities to primary ciliary dyskinesia, Cby−/− mice may prove to be a useful model for this condition.
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Affiliation(s)
- Vera A Voronina
- Department of Pharmacology, Howard Hughes Medical Institute, USA
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31
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Lembo A, Pelletier M, Iyer R, Timko M, Dudda JC, West TE, Wilson CB, Hajjar AM, Skerrett SJ. Administration of a synthetic TLR4 agonist protects mice from pneumonic tularemia. J Immunol 2008; 180:7574-81. [PMID: 18490759 DOI: 10.4049/jimmunol.180.11.7574] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Francisella tularensis is a Gram-negative intracellular pathogen that causes the zoonosis tularemia. Because F. tularensis LPS causes weak TLR4 activation, we hypothesized that administration of a synthetic TLR4 agonist, aminoalkyl glucosaminide phosphate (AGP), would boost the innate immune system and compensate for reduced TLR4 stimulation. Intranasal administration of AGPs induced intrapulmonary production of proinflammatory cytokines and chemokines. Mice treated with AGPs before and after inhalation of Francisella novicida exhibited augmented cytokine and inflammatory responses to infection; reduced bacterial replication in lung, liver, and spleen; and increased survival, whereas all PBS-treated control mice died within 4 days of infection, all AGP-treated mice showed prolonged time-to-death, and 30-60% of AGP-treated mice survived. The protective effect of AGP was lost in mice lacking IFN-gamma. Long-term survivors developed specific Th1 splenocyte responses and specific Abs dominated by IgG2 isotypes. Survivors were fully protected from rechallenge with aerosolized F. novicida. Thus, preventive administration of AGP successfully modulated innate immune responses to aerosolized F. novicida, leading to protective immunity to pneumonic tularemia. This is the first report of the protective effect of a TLR ligand on resistance to F. novicida-induced pneumonic tularemia.
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Affiliation(s)
- Annalisa Lembo
- Department of Medicine, University of Washington, Seattle, WA 98104, USA
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Wurfel MM, Gordon AC, Holden TD, Radella F, Strout J, Kajikawa O, Ruzinski JT, Rona G, Black RA, Stratton S, Jarvik GP, Hajjar AM, Nickerson DA, Rieder M, Sevransky J, Maloney JP, Moss M, Martin G, Shanholtz C, Garcia JGN, Gao L, Brower R, Barnes KC, Walley KR, Russell JA, Martin TR. Toll-like receptor 1 polymorphisms affect innate immune responses and outcomes in sepsis. Am J Respir Crit Care Med 2008; 178:710-20. [PMID: 18635889 DOI: 10.1164/rccm.200803-462oc] [Citation(s) in RCA: 175] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
RATIONALE Polymorphisms affecting Toll-like receptor (TLR)-mediated responses could predispose to excessive inflammation during an infection and contribute to an increased risk for poor outcomes in patients with sepsis. OBJECTIVES To identify hypermorphic polymorphisms causing elevated TLR-mediated innate immune cytokine and chemokine responses and to test whether these polymorphisms are associated with increased susceptibility to death, organ dysfunction, and infections in patients with sepsis. METHODS We screened single-nucleotide polymorphisms (SNPs) in 43 TLR-related genes to identify variants affecting TLR-mediated inflammatory responses in blood from healthy volunteers ex vivo. The SNP associated most strongly with hypermorphic responses was tested for associations with death, organ dysfunction, and type of infection in two studies: a nested case-control study in a cohort of intensive care unit patients with sepsis, and a case-control study using patients with sepsis, patients with sepsis-related acute lung injury, and healthy control subjects. MEASUREMENTS AND MAIN RESULTS The SNP demonstrating the most hypermorphic effect was the G allele of TLR1(-7202A/G) (rs5743551), which associated with elevated TLR1-mediated cytokine production (P < 2 x 10(-20)). TLR1(-7202G) marked a coding SNP that causes higher TLR1-induced NF-kappaB activation and higher cell surface TLR1 expression. In the cohort of patients with sepsis TLR1(-7202G) predicted worse organ dysfunction and death (odds ratio, 1.82; 95% confidence interval, 1.07-3.09). In the case-control study TLR1(-7202G) was associated with sepsis-related acute lung injury (odds ratio, 3.40; 95% confidence interval, 1.59-7.27). TLR1(-7202G) also associated with a higher prevalence of gram-positive cultures in both clinical studies. CONCLUSIONS Hypermorphic genetic variation in TLR1 is associated with increased susceptibility to organ dysfunction, death, and gram-positive infection in sepsis.
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Affiliation(s)
- Mark M Wurfel
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Washington, Seattle, Washington, USA.
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Kanistanon D, Hajjar AM, Pelletier MR, Gallagher LA, Kalhorn T, Shaffer SA, Goodlett DR, Rohmer L, Brittnacher MJ, Skerrett SJ, Ernst RK. A Francisella mutant in lipid A carbohydrate modification elicits protective immunity. PLoS Pathog 2008; 4:e24. [PMID: 18266468 PMCID: PMC2233673 DOI: 10.1371/journal.ppat.0040024] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Accepted: 12/21/2007] [Indexed: 11/18/2022] Open
Abstract
Francisella tularensis (Ft) is a highly infectious Gram-negative bacterium and the causative agent of the human disease tularemia. Ft is designated a class A select agent by the Centers for Disease Control and Prevention. Human clinical isolates of Ft produce lipid A of similar structure to Ft subspecies novicida (Fn), a pathogen of mice. We identified three enzymes required for Fn lipid A carbohydrate modifications, specifically the presence of mannose (flmF1), galactosamine (flmF2), or both carbohydrates (flmK). Mutants lacking either galactosamine (flmF2) or galactosamine/mannose (flmK) addition to their lipid A were attenuated in mice by both pulmonary and subcutaneous routes of infection. In addition, aerosolization of the mutants (flmF2 and flmK) provided protection against challenge with wild-type (WT) Fn, whereas subcutaneous administration of only the flmK mutant provided protection from challenge with WT Fn. Furthermore, infection of an alveolar macrophage cell line by the flmK mutant induced higher levels of tumor necrosis factor-α (TNF-α) and macrophage inhibitory protein-2 (MIP-2) when compared to infection with WT Fn. Bone marrow–derived macrophages (BMMø) from Toll-like receptor 4 (TLR4) and TLR2/4 knockout mice infected with the flmK mutant also produced significantly higher amounts of interleukin-6 (IL-6) and MIP-2 than BMMø infected with WT Fn. However, production of IL-6 and MIP-2 was undetectable in BMMø from MyD88−/− mice infected with either strain. MyD88−/− mice were also susceptible to flmK mutant infection. We hypothesize that the ability of the flmK mutant to activate pro-inflammatory cytokine/chemokine production and innate immune responses mediated by the MyD88 signaling pathway may be responsible for its attenuation, leading to the induction of protective immunity by this mutant. Bacterial pathogens modify outer membrane components, such as lipid A or endotoxin, the lipid anchor of lipopolysaccharide, to enhance the ability to colonize, spread to different tissues, and/or avoid the host's immune defenses. Lipopolysaccharide also plays an essential role in maintaining membrane integrity and is a key factor in host innate immune recognition of Gram-negative bacterial infections. Francisella tularensis is the causative agent of the human disease tularemia and is classified as a category A select agent. Francisella novicida (Fn) is the murine counterpart of F. tularensis. The structure of Francisella spp. lipid A is unique in that it is modified by various carbohydrates that play a role in virulence and altered endotoxicity. In our study, we identified and defined the role of three genes involved in the carbohydrate modification of the base Fn lipid A structure. We showed that the lack of specific modification(s) of the Fn lipid A molecule lead to bacterial attenuation and activation of a protective immune response against a lethal wild-type infection. Therefore, alteration of Francisella lipid A structure may represent a pathogenesis strategy common to the Francisella species, and specific lipid A mutant strains may be candidates for inclusion in future vaccine studies.
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Affiliation(s)
- Duangjit Kanistanon
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Adeline M Hajjar
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
| | - Mark R Pelletier
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Larry A Gallagher
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Thomas Kalhorn
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, United States of America
| | - Scott A Shaffer
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, United States of America
| | - David R Goodlett
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, United States of America
| | - Laurence Rohmer
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Mitchell J Brittnacher
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Shawn J Skerrett
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Robert K Ernst
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- * To whom correspondence should be addressed. E-mail:
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West TE, Pelletier MR, Majure MC, Lembo A, Hajjar AM, Skerrett SJ. Inhalation of Francisella novicida Delta mglA causes replicative infection that elicits innate and adaptive responses but is not protective against invasive pneumonic tularemia. Microbes Infect 2008; 10:773-80. [PMID: 18539500 DOI: 10.1016/j.micinf.2008.04.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2007] [Revised: 03/25/2008] [Accepted: 04/14/2008] [Indexed: 12/29/2022]
Abstract
Francisella tularensis causes the zoonosis tularemia in humans, and inhaled F. tularensis ssp. novicida induces lethal murine tularemia. Transcription of virulence factors in F. novicida is regulated by macrophage growth locus A (mglA), a global regulator required for bacterial replication in macrophages in vitro. We examined the infectivity and immunogenicity of attenuated F. novicida Delta mglA in the lung in vivo. Aerosolized Delta mglA caused replicative pulmonary infection that peaked at 7 days and was cleared thereafter, without clinical evidence of disease. In contrast, inhalation of wild type F. novicida resulted in more rapid bacterial replication and dissemination leading to death within 96 h. Early containment of Delta mglA infection was partially dependent on myeloid differentiation factor 88 and interferon-gamma but did not require B or T cells. However, lymphocytes were necessary for subsequent bacterial clearance. Infection with Delta mglA elicited specific IgG1-predominant antibodies and variable interferon-gamma recall responses to wild type F. novicida. Inoculation of mice with aerosolized Delta mglA afforded no protection against a subsequent low-dose aerosol challenge with wild type F. novicida. These findings establish that inhalation of F. novicida Delta mglA results in replicative infection that elicits innate and adaptive immune responses but not protective immunity against invasive pneumonic tularemia.
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Affiliation(s)
- T Eoin West
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Harborview Medical Center, University of Washington, Box 359640, Seattle, WA 98104-2499, USA.
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Kollmann TR, Reikie B, Blimkie D, Way SS, Hajjar AM, Arispe K, Shaulov A, Wilson CB. Induction of protective immunity to Listeria monocytogenes in neonates. J Immunol 2007; 178:3695-701. [PMID: 17339467 PMCID: PMC2706399 DOI: 10.4049/jimmunol.178.6.3695] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Neonates suffer unduly from infections and also respond suboptimally to most commonly used vaccines. However, a CD8 T cell response can be elicited in neonates if the Ag is introduced into the cytoplasm of APCs. Listeria monocytogenes (Lm) targets the cytoplasm of APC and is a strong CD8 and CD4 Th1-promoting vaccine vehicle in adult mice. We hypothesized that an attenuated strain of Lm would be safe and induce long-lasting protective immunity, even in neonates. We found that neonatal mice immunized only once with the attenuated strain DeltaactA-Lm developed robust primary and secondary CD8 and CD4 Th1 responses and were fully protected from lethal challenge with virulent wild-type Lm without the need for a booster immunization. Furthermore, DeltaactA-Lm expressing a heterologous recombinant Ag induced a strong CD8 and Th1 memory response to that Ag. Based on these data, we propose that DeltaactA-Lm or derivatives thereof might serve as a vaccine vehicle for neonatal immunization.
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Affiliation(s)
- Tobias R Kollmann
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195, USA.
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Hajjar AM, Harvey MD, Shaffer SA, Goodlett DR, Sjöstedt A, Edebro H, Forsman M, Byström M, Pelletier M, Wilson CB, Miller SI, Skerrett SJ, Ernst RK. Lack of in vitro and in vivo recognition of Francisella tularensis subspecies lipopolysaccharide by Toll-like receptors. Infect Immun 2006; 74:6730-8. [PMID: 16982824 PMCID: PMC1698081 DOI: 10.1128/iai.00934-06] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Francisella tularensis is an intracellular gram-negative bacterium that is highly infectious and potentially lethal. Several subspecies exist of varying pathogenicity. Infection by only a few organisms is sufficient to cause disease depending on the model system. Lipopolysaccharide (LPS) of gram-negative bacteria is generally recognized by Toll-like receptor 4 (TLR4)/MD-2 and induces a strong proinflammatory response. Examination of human clinical F. tularensis isolates revealed that human virulent type A and type B strains produced lipid A of similar structure to the nonhuman model pathogen of mice, Francisella novicida. F. novicida LPS or lipid A is neither stimulatory nor an antagonist for human and murine cells through TLR4 or TLR2. It does not appear to interact with TLR4 or MD-2, as it is not an antagonist to other stimulatory LPS. Consistent with these observations, aerosolization of F. novicida LPS or whole bacteria induced no inflammatory response in mice. These results suggest that poor innate recognition of F. tularensis allows the bacterium to evade early recognition by the host innate immune system to promote its pathogenesis for mammals.
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Affiliation(s)
- Adeline M Hajjar
- Department of Medicine, University of Washington, Health Sciences Building, Box 357710, 1959 NE Pacific Street, Seattle, WA 98195, USA
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Skerrett SJ, Wilson CB, Liggitt HD, Hajjar AM. Redundant Toll-like receptor signaling in the pulmonary host response to Pseudomonas aeruginosa. Am J Physiol Lung Cell Mol Physiol 2006; 292:L312-22. [PMID: 16936244 DOI: 10.1152/ajplung.00250.2006] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Activation of pulmonary defenses against Pseudomonas aeruginosa requires myeloid differentiation factor 88 (MyD88), an adaptor for Toll-like receptor (TLR) signaling. To determine which TLRs mediate recognition of P. aeruginosa, we measured cytokine responses of bone marrow cells from wild-type mice and mice lacking TLR2 (TLR2(-/-)), TLR4 (TLR4(-/-)), TLR2 and TLR4 (TLR2/4(-/-)), or MyD88 (MyD88(-/-)) to wild-type P. aeruginosa and to fliC P. aeruginosa, which lacks the TLR5 ligand flagellin. Mice also were challenged with aerosolized bacteria to determine cytokine responses, lung inflammation, and bacterial clearance. TNF induction required MyD88 and was absent in TLR2/4(-/-) cells in response to fliC but not wild-type P. aeruginosa, whereas TLR2(-/-) cells exhibited augmented responses. In vivo, TLR4(-/-) mice responded to wild-type P. aeruginosa with reduced cytokine production and inflammation, but intact bacterial clearance, while TLR2(-/-) mice had partially impaired cytokine responses and delayed bacterial killing despite normal inflammation. When challenged with fliC, MyD88(-/-) mice failed to mount early cytokine and inflammatory responses or control bacterial replication, resulting in necrotizing lung injury and lethal disseminated infection. TLR4(-/-) and TLR2/4(-/-) mice responded to fliC infection with severely limited inflammatory and cytokine responses but intact bacterial clearance. TLR2(-/-) mice had partially reduced cytokine responses but augmented inflammation and preserved bacterial killing. These data indicate that TLR4- and flagellin-induced signals mediate most of the acute inflammatory response to Pseudomonas and that TLR2 has a counterregulatory role. However, MyD88-dependent pathways, in addition to those downstream of TLR2, TLR4, and TLR5, are required for pulmonary defense against P. aeruginosa.
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Affiliation(s)
- Shawn J Skerrett
- Division of Pulmonary and Critical Care Medicine, Harborview Medical Center, 325 Ninth Avenue, Box 359640, Seattle, WA 98104, USA.
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Hajjar AM, Harowicz H, Liggitt HD, Fink PJ, Wilson CB, Skerrett SJ. An essential role for non-bone marrow-derived cells in control of Pseudomonas aeruginosa pneumonia. Am J Respir Cell Mol Biol 2005; 33:470-5. [PMID: 16100080 PMCID: PMC2715354 DOI: 10.1165/rcmb.2005-0199oc] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
MyD88 is an adapter protein required for the induction of proinflammatory cytokines by most Toll-like receptors (TLR), and Pseudomonas aeruginosa expresses ligands for multiple TLRs. MyD88(-/-) (KO) mice are highly susceptible to aerosolized P. aeruginosa, failing to elicit an early inflammatory response and permitting a 3-log increase in bacterial CFU in the lungs by 24 h after infection. We hypothesized that alveolar macrophages are the first cells to recognize and kill aerosolized P. aeruginosa in an MyD88-dependent fashion due to their location within the airways. To determine which cells in the lungs mediate MyD88-dependent defenses against P. aeruginosa, we generated radiation bone marrow (BM) chimeras between MyD88KO and wild-type (WT) mice. MyD88KO mice transplanted with MyD88KO BM (MyD88KO-->MyD88KO mice) displayed uncontrolled bacterial replication, whereas all other chimeras controlled the infection by 24 h. However, at 4 h, both MyD88KO-->MyD88KO and WT-->MyD88KO mice permitted intrapulmonary bacterial replication, whereas MyD88KO-->WT and WT-->WT mice did not, indicating that the source of BM had little impact on the early control of infection. Similarly, the genotype of the recipient rather than that of the BM donor determined early neutrophil recruitment to the lungs. Whereas intrapulmonary TNF-alpha and IL-1beta production were associated with WT BM, levels of the CXC chemokines MIP-2 and KC as well as GM-CSF were associated with recipient genotype. We conclude that lung parenchymal and BM-derived cells collaborate in the MyD88-dependent response to P. aeruginosa infection in the lungs in mice.
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MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Adaptor Proteins, Signal Transducing/metabolism
- Animals
- Antigens, Differentiation/genetics
- Antigens, Differentiation/metabolism
- Bone Marrow Cells/immunology
- Bone Marrow Cells/metabolism
- Chemokines/metabolism
- Cytokines/metabolism
- Lung/microbiology
- Lung/pathology
- Macrophages, Alveolar/immunology
- Macrophages, Alveolar/metabolism
- Macrophages, Alveolar/microbiology
- Mice
- Mice, Knockout
- Myeloid Differentiation Factor 88
- Pneumonia, Bacterial/genetics
- Pneumonia, Bacterial/immunology
- Pneumonia, Bacterial/pathology
- Pseudomonas Infections/genetics
- Pseudomonas Infections/immunology
- Pseudomonas Infections/pathology
- Pseudomonas aeruginosa
- Radiation Chimera
- Receptors, Immunologic/genetics
- Receptors, Immunologic/metabolism
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Affiliation(s)
- Adeline M Hajjar
- Department of Immunology, University of Washington School of Medicine, Seattle, Washington 98195, USA.
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39
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Krishnegowda G, Hajjar AM, Zhu J, Douglass EJ, Uematsu S, Akira S, Woods AS, Gowda DC. Induction of proinflammatory responses in macrophages by the glycosylphosphatidylinositols of Plasmodium falciparum: cell signaling receptors, glycosylphosphatidylinositol (GPI) structural requirement, and regulation of GPI activity. J Biol Chem 2005; 280:8606-16. [PMID: 15623512 PMCID: PMC4984258 DOI: 10.1074/jbc.m413541200] [Citation(s) in RCA: 377] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The glycosylphosphatidylinositol (GPI) anchors of Plasmodium falciparum have been proposed to be the major factors that contribute to malaria pathogenesis through their ability to induce proinflammatory responses. In this study we identified the receptors for P. falciparum GPI-induced cell signaling that leads to proinflammatory responses and studied the GPI structure-activity relationship. The data show that GPI signaling is mediated mainly through recognition by TLR2 and to a lesser extent by TLR4. The activity of sn-2-lyso-GPIs is comparable with that of the intact GPIs, whereas the activity of Man(3)-GPIs is about 80% that of the intact GPIs. The GPIs with three (intact GPIs and Man(3)-GPIs) and two fatty acids (sn-2-lyso-GPIs) appear to differ considerably in the requirement of the auxiliary receptor, TLR1 or TLR6, for recognition by TLR2. The former are preferentially recognized by TLR2/TLR1, whereas the latter are favored by TLR2/TLR6. However, the signaling pathways initiated by all three GPI types are similar, involving the MyD88-dependent activation of extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38 and NF-kappaB-signaling pathways. The signaling molecules of these pathways differentially contribute to the production of various cytokines and nitric oxide (Zhu, J., Krishnegowda, G., and Gowda, D. C. (2004) J. Biol. Chem. 280, 8617-8627). Our data also show that GPIs are degraded by the macrophage surface phospholipases predominantly into inactive species, indicating that the host can regulate GPI activity at least in part by this mechanism. These results imply that macrophage surface phospholipases play important roles in the GPI-induced innate immune responses and malaria pathogenesis.
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Affiliation(s)
| | | | | | | | - Satoshi Uematsu
- Department of Host Defense, Research Institutes for Microbial Diseases, Osaka University, Japan
| | - Shizuo Akira
- Department of Host Defense, Research Institutes for Microbial Diseases, Osaka University, Japan
| | | | - D. Channe Gowda
- Address for correspondence to: Adeline Hajjar, Department of Immunology, Box 357650, University of Washington, Seattle, WA 98195, Phone: 206-221-2817; or D. Channe Gowda, Department of Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA, Phone: (717) 531-0992; Fax: (717) 531-7072;
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40
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Darveau RP, Pham TTT, Lemley K, Reife RA, Bainbridge BW, Coats SR, Howald WN, Way SS, Hajjar AM. Porphyromonas gingivalis lipopolysaccharide contains multiple lipid A species that functionally interact with both toll-like receptors 2 and 4. Infect Immun 2004; 72:5041-51. [PMID: 15321997 PMCID: PMC517442 DOI: 10.1128/iai.72.9.5041-5051.2004] [Citation(s) in RCA: 393] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2004] [Revised: 04/19/2004] [Accepted: 05/26/2004] [Indexed: 12/16/2022] Open
Abstract
The innate host response to lipopolysaccharide (LPS) obtained from Porphyromonas gingivalis is unusual in that different studies have reported that it can be an agonist for Toll-like receptor 2 (TLR2) as well as an antagonist or agonist for TLR4. In this report it is shown that P. gingivalis LPS is highly heterogeneous, containing more lipid A species than previously described. In addition, purification of LPS can preferentially fractionate these lipid A species. It is shown that an LPS preparation enriched for lipid A species at m/z 1,435 and 1,450 activates human and mouse TLR2, TLR2 plus TLR1, and TLR4 in transiently transfected HEK 293 cells coexpressing membrane-associated CD14. The HEK cell experiments further demonstrated that cofactor MD-2 was required for functional engagement of TLR4 but not of TLR2 nor TLR2 plus TLR1. In addition, serum-soluble CD14 effectively transferred P. gingivalis LPS to TLR2 plus TLR1, but poorly to TLR4. Importantly, bone marrow cells obtained from TLR2(-/-) and TLR4(-/-) mice also responded to P. gingivalis LPS in a manor consistent with the HEK results, demonstrating that P. gingivalis LPS can utilize both TLR2 and TLR4. No response was observed from bone marrow cells obtained from TLR2 and TLR4 double-knockout mice, demonstrating that P. gingivalis LPS activation occurred exclusively through either TLR2 or TLR4. Although the biological significance of the different lipid A species found in P. gingivalis LPS preparations is not currently understood, it is proposed that the presence of multiple lipid A species contributes to cell activation through both TLR2 and TLR4.
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Affiliation(s)
- Richard P Darveau
- Department of Periodontics, University of Washington, Health Sciences Center, Box 357444, Seattle, WA 98195, USA.
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41
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Ernst RK, Hajjar AM, Tsai JH, Moskowitz SM, Wilson CB, Miller SI. Pseudomonas aeruginosa lipid A diversity and its recognition by Toll-like receptor 4. ACTA ACUST UNITED AC 2004; 9:395-400. [PMID: 14733728 DOI: 10.1179/096805103225002764] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Lipid A is the pro-inflammatory component of bacterial lipopolysaccharide, the major surface component of Gram-negative bacteria. Gram-negative bacteria alter the structure of lipid A in response to specific environmental conditions including those found upon colonization of a host. The opportunistic pathogen Pseudomonas aeruginosa synthesizes a unique hexa-acylated lipid A containing palmitate and aminoarabinose during adaptation to the cystic fibrosis airway. Different lipid A species are observed in P. aeruginosa isolated from non-cystic fibrosis associated infections. Here we report that P. aeruginosa isolates from the airway of a cystic fibrosis patient with severe pulmonary disease synthesized a novel hepta-acylated lipid A. Cystic fibrosis-specific P. aeruginosa lipid A modifications result in resistance to host antimicrobial peptides and increased recognition by human Toll-like receptor 4 (TLR4). Using P. aeruginosa lipid A with different levels of acylation, we identified a 222 amino acid region in the extracellular portion of human TLR4 that is required for the differential recognition of cystic fibrosis-specific lipid A. P. aeruginosa adaptation to the human airway may, therefore, play a fundamental role in the progressive lung damage associated with cystic fibrosis.
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Affiliation(s)
- Robert K Ernst
- Department of Medicine, HSB K-155, Box 357710, University of Washington, Seattle, WA 98195, USA.
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42
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Skerrett SJ, Liggitt HD, Hajjar AM, Wilson CB. Cutting edge: myeloid differentiation factor 88 is essential for pulmonary host defense against Pseudomonas aeruginosa but not Staphylococcus aureus. J Immunol 2004; 172:3377-81. [PMID: 15004134 DOI: 10.4049/jimmunol.172.6.3377] [Citation(s) in RCA: 147] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Myeloid differentiation factor 88 (MyD88) is an adapter molecule required for signal transduction via Toll-like receptors (TLRs) and receptors of the IL-1 family. Consequently, MyD88-deficient mice are highly susceptible to bacterial infections, including systemic infection with Staphylococcus aureus. To determine the role of MyD88 in innate immunity to bacterial pneumonia, we exposed MyD88-deficient and wild-type mice to aerosolized Pseudomonas aeruginosa or S. aureus. As predicted, MyD88-deficient mice failed to mount an early cytokine or inflammatory response or to control bacterial replication after infection with P. aeruginosa, which resulted in necrotizing pneumonia and death. By contrast, MyD88-deficient mice controlled S. aureus infection despite blunted local cytokine and inflammatory responses. Thus, whereas MyD88-dependent signaling is integral to the initiation of cytokine and inflammatory responses to both pathogens following infection of the lower respiratory tract, MyD88 is essential for innate immunity to P. aeruginosa but not S. aureus.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Animals
- Antigens, Differentiation/genetics
- Antigens, Differentiation/physiology
- Cytokines/biosynthesis
- Genetic Predisposition to Disease
- Immunity, Innate/genetics
- Inflammation Mediators/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Myeloid Differentiation Factor 88
- Necrosis
- Neutrophil Infiltration/genetics
- Pneumonia, Bacterial/genetics
- Pneumonia, Bacterial/immunology
- Pneumonia, Bacterial/pathology
- Pseudomonas Infections/genetics
- Pseudomonas Infections/immunology
- Pseudomonas Infections/pathology
- Pseudomonas aeruginosa/immunology
- Receptors, Immunologic/deficiency
- Receptors, Immunologic/genetics
- Receptors, Immunologic/physiology
- Respiratory Mucosa/immunology
- Respiratory Mucosa/metabolism
- Respiratory Mucosa/pathology
- Signal Transduction/genetics
- Signal Transduction/immunology
- Species Specificity
- Staphylococcal Infections/genetics
- Staphylococcal Infections/immunology
- Staphylococcal Infections/pathology
- Staphylococcus aureus/immunology
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Affiliation(s)
- Shawn J Skerrett
- Department of Medicine, University of Washington, School of Medicine, Seattle, WA 98195, USA.
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43
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Abstract
Abstract
Neonates respond suboptimally to many vaccines. The reasons for this defect are unclear, but suboptimal antigen presentation by dendritic cells has been suggested as one possibility. In this report we describe an in vitro system that allows the generation of large numbers of resting murine neonatal dendritic cells facilitating their study. Using this system, we show a clear reduction in the ability of neonatal dendritic cells to present soluble ovalbumin, while the capacity to present ovalbumin peptide is intact. This suggests a specific defect in cross-presentation of exogenous antigen via the major histocompatibility complex (MHC) class I pathway. Deficient cross-presentation may contribute to the suboptimal CD8 T-cell response to vaccines in neonates. (Blood. 2004;103:4240-4242)
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Affiliation(s)
- Tobias R Kollmann
- Department of Immunology, Box 357650, University of Washington, Seattle, WA 98165, USA
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Skerrett SJ, Liggitt HD, Hajjar AM, Ernst RK, Miller SI, Wilson CB. Respiratory epithelial cells regulate lung inflammation in response to inhaled endotoxin. Am J Physiol Lung Cell Mol Physiol 2004; 287:L143-52. [PMID: 15047567 DOI: 10.1152/ajplung.00030.2004] [Citation(s) in RCA: 163] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To determine the role of respiratory epithelial cells in the inflammatory response to inhaled endotoxin, we selectively inhibited NF-kappa B activation in the respiratory epithelium using a mutant I kappa B-alpha construct that functioned as a dominant negative inhibitor of NF-kappa B translocation (dnI kappa B-alpha). We developed two lines of transgenic mice in which expression of dnI kappa B-alpha was targeted to the distal airway epithelium using the human surfactant apoprotein C promoter. Transgene expression was localized to the epithelium of the terminal bronchioles and alveoli. After inhalation of LPS, nuclear translocation of NF-kappa B was evident in bronchiolar epithelium of nontransgenic but not of transgenic mice. This defect was associated with impaired neutrophilic lung inflammation 4 h after LPS challenge and diminished levels of TNF-alpha, IL-1 beta, macrophage inflammatory protein-2, and KC in lung homogenates. Expression of TNF-alpha within bronchiolar epithelial cells and of VCAM-1 within peribronchiolar endothelial cells was reduced in transgenic animals. Thus targeted inhibition of NF-kappa B activation in distal airway epithelial cells impaired the inflammatory response to inhaled LPS. These data provide causal evidence that distal airway epithelial cells and the signals they transduce play a physiological role in lung inflammation in vivo.
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Affiliation(s)
- Shawn J Skerrett
- Department of Medicine, University of Washington School of Medicine, Seattle, 98104, USA.
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45
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Way SS, Thompson LJ, Lopes JE, Hajjar AM, Kollmann TR, Freitag NE, Wilson CB. Characterization of flagellin expression and its role in Listeria monocytogenes infection and immunity. Cell Microbiol 2004; 6:235-42. [PMID: 14764107 DOI: 10.1046/j.1462-5822.2004.00360.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Flagellin is the structural component of flagella produced by many pathogenic bacteria and is a potent proinflammatory molecule that mediates these effects through Toll-like receptor (TLR) 5. In Listeria monocytogenes (LM), flagellin expression is regulated by temperature and has been described as being shut off at 37 degrees C. In this study, we demonstrate that TLR5-mediated cell activation and flagellin expression is maintained at 37 degrees C in some laboratory-adapted strains and in approximately 20% of LM clinical isolates. To determine the role of flagellin in LM infection, a targeted mutation in the structural gene for flagellin (flaA) was generated in a parental LM strain that expressed flagellin under all conditions examined. In vitro studies demonstrated that this deltaflaA mutant was (i). non-motile; (ii). not able to activate TLR5-transfected HeLa cells; and (iii). induced tumour necrosis factor (TNF)-alpha production in approximately 50% fewer CD11b+ cells in splenocytes from normal mice compared with the parental strain. However, there was no significant alteration in virulence of the deltaflaA mutant after either intravenous or oral murine infection. Similarly, there was no difference in the generation of LM-specific CD8 or CD4 T cells after intravenous or oral infection. These data indicate that flagellin is not essential for LM pathogenesis or for the induction of LM-specific adaptive immune responses in normal mice.
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Affiliation(s)
- Sing Sing Way
- Department of Pediatrics, University of Washington School of Medicine, 1959 NE Pacific Street, Box 357650, H564, Seattle, WA 98195, USA
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Way SS, Kollmann TR, Hajjar AM, Wilson CB. Cutting edge: protective cell-mediated immunity to Listeria monocytogenes in the absence of myeloid differentiation factor 88. J Immunol 2003; 171:533-7. [PMID: 12847214 DOI: 10.4049/jimmunol.171.2.533] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
In addition to their role in triggering innate immune responses, Toll-like receptors are proposed to play a key role in linking the innate and adaptive arms of the immune response. The majority of cellular responses downstream of Toll-like receptors are mediated through the adapter molecule myeloid differentiation factor 88 (MyD88), and mice with a targeted deletion of MyD88 are highly susceptible to bacterial infections, including primary infection with Listeria monocytogenes (LM). In contrast, herein we demonstrate that MyD88-deficient mice have only a modest impairment in their LM-specific CD4 T cell response, and no impairment in their CD8 T cell response following infection with ActA-deficient LM. Furthermore, CD8 T cells from immunized MyD88-deficient mice protected naive recipient mice following adoptive splenocyte transfer, and immunized MyD88-deficient mice were protected from infection with wild-type LM. These results indicate that adaptive immune responses can be generated and provide protective immunity in the absence of MyD88.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Adoptive Transfer
- Animals
- Antigens, Differentiation/genetics
- Antigens, Differentiation/physiology
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/microbiology
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/microbiology
- Dose-Response Relationship, Immunologic
- Epitopes, T-Lymphocyte/immunology
- Genetic Predisposition to Disease
- Immunity, Cellular/genetics
- Immunity, Innate/genetics
- Listeria monocytogenes/genetics
- Listeria monocytogenes/immunology
- Listeriosis/genetics
- Listeriosis/immunology
- Listeriosis/microbiology
- Lymphocyte Activation/genetics
- Lymphocyte Activation/immunology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Myeloid Differentiation Factor 88
- Receptors, Immunologic/deficiency
- Receptors, Immunologic/genetics
- Receptors, Immunologic/physiology
- Spleen/cytology
- Spleen/immunology
- Spleen/transplantation
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Affiliation(s)
- Sing Sing Way
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195, USA
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47
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Abstract
Lipopolysaccharide (LPS) is the principal proinflammatory component of the Gram-negative bacterial envelope and is recognized by the Toll-like receptor 4 (TLR4)-MD-2 receptor complex. Bacteria can alter the acylation state of their LPS in response to environmental changes. One opportunistic bacterium, Pseudomonas aeruginosa, synthesizes more highly acylated (hexa-acylated) LPS structures during adaptation to the cystic fibrosis airway. Here we show that human, but not murine, TLR4-MD-2 recognizes this adaptation and transmits robust proinflammatory signals in response to hexa-acylated but not penta-acylated LPS from P. aeruginosa. Whereas responses to lipidIVA and taxol are dependent on murine MD-2, discrimination of P. aeruginosa LPS structures is mediated by an 82-amino-acid region of human TLR4 that is hypervariable across species. Thus, in contrast to mice, humans use TLR4 to recognize a molecular signature of bacterial-host adaptation to modulate the innate immune response.
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Affiliation(s)
- Adeline M Hajjar
- Department of Immunology, University of Washington, Seattle, WA 98195, USA
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48
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Hajjar AM, O'Mahony DS, Ozinsky A, Underhill DM, Aderem A, Klebanoff SJ, Wilson CB. Cutting edge: functional interactions between toll-like receptor (TLR) 2 and TLR1 or TLR6 in response to phenol-soluble modulin. J Immunol 2001; 166:15-9. [PMID: 11123271 DOI: 10.4049/jimmunol.166.1.15] [Citation(s) in RCA: 344] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Toll-like receptor (TLR) 2 and TLR4 play important roles in the early, innate immune response to microbial challenge. TLR2 is preferentially involved in the inflammatory response to lipoteichoic acid, lipopeptides, and glycans from a variety of microbes, whereas TLR4 is essential for a complete response to LPSs. We report here that TLR2 transduces the response to phenol-soluble modulin, a factor secreted by Staphylococcus epidermidis. The TLR2-mediated response to this modulin was enhanced by TLR6 but inhibited by TLR1, indicating a functional interaction between these receptors. We also demonstrate that a response to phenol-soluble modulin mediated by TLR2 and TLR6 was more refractory to inhibition by TLR1 than one mediated by TLR2 alone.
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Affiliation(s)
- A M Hajjar
- Department of Immunology, University of Washington, Seattle, WA 98195, USA
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49
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Ozinsky A, Underhill DM, Fontenot JD, Hajjar AM, Smith KD, Wilson CB, Schroeder L, Aderem A. The repertoire for pattern recognition of pathogens by the innate immune system is defined by cooperation between toll-like receptors. Proc Natl Acad Sci U S A 2000; 97:13766-71. [PMID: 11095740 PMCID: PMC17650 DOI: 10.1073/pnas.250476497] [Citation(s) in RCA: 1450] [Impact Index Per Article: 60.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Toll-like receptors (TLRs) have been shown to participate in the recognition of pathogens by the innate immune system, but it is not clear how a restricted family of receptors has the capacity to recognize the wide spectrum of TLR stimuli known to exist. We report here that two members of the TLR family, TLR2 and TLR6, together coordinate macrophage activation by Gram-positive bacteria and the yeast cell-wall particle, zymosan. TLR6 and TLR2 both are recruited to the macrophage phagosome, where they recognize peptidoglycan, a Gram-positive pathogen component. By contrast, TLR2 recognizes another component, bacterial lipopeptide, without TLR6. The requirement for TLR cooperation is supported by the finding that TLR2 needs a partner to activate tumor necrosis factor-alpha production in macrophages. Dimerization of the cytoplasmic domain of TLR2 does not induce tumor necrosis factor-alpha production in macrophages, whereas similar dimerization of the TLR4 cytoplasmic domain does. We show that the cytoplasmic domain of TLR2 can form functional pairs with TLR6 or TLR1, and this interaction leads to cytokine induction. Thus, the cytoplasmic tails of TLRs are not functionally equivalent, with certain TLRs requiring assembly into heteromeric complexes, whereas others are active as homomeric complexes. Finally, we show that TLR6, TLR2, and TLR1 are recruited to macrophage phagosomes that contain IgG-coated erythrocytes that do not display microbial components. The data suggest that TLRs sample the contents of the phagosome independent of the nature of the contents, and can establish a combinatorial repertoire to discriminate among the large number of pathogen-associated molecular patterns found in nature.
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Affiliation(s)
- A Ozinsky
- Department of Immunology, University of Washington, H-574 Health Sciences, Box 357650, Seattle, WA 98195, USA
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50
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Underhill DM, Ozinsky A, Hajjar AM, Stevens A, Wilson CB, Bassetti M, Aderem A. The Toll-like receptor 2 is recruited to macrophage phagosomes and discriminates between pathogens. Nature 1999; 401:811-5. [PMID: 10548109 DOI: 10.1038/44605] [Citation(s) in RCA: 1036] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Macrophages orchestrate innate immunity by phagocytosing pathogens and coordinating inflammatory responses. Effective defence requires the host to discriminate between different pathogens. The specificity of innate immune recognition in Drosophila is mediated by the Toll family of receptors; Toll mediates anti-fungal responses, whereas 18-wheeler mediates anti-bacterial defence. A large number of Toll homologues have been identified in mammals, and Toll-like receptor 4 is critical in responses to Gram-negative bacteria. Here we show that Toll-like receptor 2 is recruited specifically to macrophage phagosomes containing yeast, and that a point mutation in the receptor abrogates inflammatory responses to yeast and Gram-positive bacteria, but not to Gram-negative bacteria. Thus, during the phagocytosis of pathogens, two classes of innate immune receptors cooperate to mediate host defence: phagocytic receptors, such as the mannose receptor, signal particle internalization, and the Toll-like receptors sample the contents of the vacuole and trigger an inflammatory response appropriate to defence against the specific organism.
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Affiliation(s)
- D M Underhill
- Department of Immunology, University of Washington, Seattle 98195, USA
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