1
|
Smythies LE, Shen R, Bimczok D, Novak L, Clements RH, Eckhoff DE, Bouchard P, George MD, Hu WK, Dandekar S, Smith PD. Inflammation anergy in human intestinal macrophages is due to Smad-induced IkappaBalpha expression and NF-kappaB inactivation. J Biol Chem 2010; 285:19593-604. [PMID: 20388715 PMCID: PMC2885238 DOI: 10.1074/jbc.m109.069955] [Citation(s) in RCA: 148] [Impact Index Per Article: 10.6] [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: 09/25/2009] [Revised: 03/15/2010] [Indexed: 12/13/2022] Open
Abstract
Human intestinal macrophages contribute to tissue homeostasis in noninflamed mucosa through profound down-regulation of pro-inflammatory cytokine release. Here, we show that this down-regulation extends to Toll-like receptor (TLR)-induced cytokine release, as intestinal macrophages expressed TLR3-TLR9 but did not release cytokines in response to TLR-specific ligands. Likely contributing to this unique functional profile, intestinal macrophages expressed markedly down-regulated adapter proteins MyD88 and Toll interleukin receptor 1 domain-containing adapter-inducing interferon beta, which together mediate all TLR MyD88-dependent and -independent NF-kappaB signaling, did not phosphorylate NF-kappaB p65 or Smad-induced IkappaBalpha, and did not translocate NF-kappaB into the nucleus. Importantly, transforming growth factor-beta released from intestinal extracellular matrix (stroma) induced identical down-regulation in the NF-kappaB signaling and function of blood monocytes, the exclusive source of intestinal macrophages. Our findings implicate stromal transforming growth factor-beta-induced dysregulation of NF-kappaB proteins and Smad signaling in the differentiation of pro-inflammatory blood monocytes into noninflammatory intestinal macrophages.
Collapse
Affiliation(s)
| | - Ruizhong Shen
- From the Departments of Medicine (Gastroenterology) and
| | - Diane Bimczok
- From the Departments of Medicine (Gastroenterology) and
| | | | | | - Devin E. Eckhoff
- Transplantation, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | | | - Michael D. George
- the Department of Medical Microbiology, University of California School of Medicine, Davis, California 95616, and
| | - William K. Hu
- the Department of Medical Microbiology, University of California School of Medicine, Davis, California 95616, and
| | - Satya Dandekar
- the Department of Medical Microbiology, University of California School of Medicine, Davis, California 95616, and
| | - Phillip D. Smith
- From the Departments of Medicine (Gastroenterology) and
- the Veterans Affairs Medical Center, Birmingham, Alabama 35233
| |
Collapse
|
2
|
Svensson SL, Pasupuleti M, Walse B, Malmsten M, Mörgelin M, Sjögren C, Olin AI, Collin M, Schmidtchen A, Palmer R, Egesten A. Midkine and pleiotrophin have bactericidal properties: preserved antibacterial activity in a family of heparin-binding growth factors during evolution. J Biol Chem 2010; 285:16105-15. [PMID: 20308059 PMCID: PMC2871479 DOI: 10.1074/jbc.m109.081232] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Revised: 03/16/2010] [Indexed: 12/17/2022] Open
Abstract
Antibacterial peptides of the innate immune system combat pathogenic microbes, but often have additional roles in promoting inflammation and as growth factors during tissue repair. Midkine (MK) and pleiotrophin (PTN) are the only two members of a family of heparin-binding growth factors. They show restricted expression during embryogenesis and are up-regulated in neoplasia. In addition, MK shows constitutive and inflammation-dependent expression in some non-transformed tissues of the adult. In the present study, we show that both MK and PTN display strong antibacterial activity, present at physiological salt concentrations. Electron microscopy of bacteria and experiments using artificial lipid bilayers suggest that MK and PTN exert their antibacterial action via a membrane disruption mechanism. The predicted structure of PTN, employing the previously solved MK structure as a template, indicates that both molecules consist of two domains, each containing three antiparallel beta-sheets. The antibacterial activity was mapped to the unordered C-terminal tails of both molecules and the last beta-sheets of the N-terminals. Analysis of the highly conserved MK and PTN orthologues from the amphibian Xenopus laevis and the fish Danio rerio suggests that they also harbor antibacterial activity in the corresponding domains. In support of an evolutionary conserved function it was found that the more distant orthologue, insect Miple2 from Drosophila melanogaster, also displays strong antibacterial activity. Taken together, the findings suggest that MK and PTN, in addition to their earlier described activities, may have previously unrealized important roles as innate antibiotics.
Collapse
Affiliation(s)
| | | | - Björn Walse
- SARomics AB, P. O. Box 724, SE-220 07 Lund, Sweden
| | - Martin Malmsten
- the Department of Pharmacy, Uppsala University, SE-751 23 Uppsala, Sweden, and
| | - Matthias Mörgelin
- Infection Medicine, Department of Clinical Sciences Lund, Lund University, University Hospital, SE-221 85 Lund, Sweden
| | - Camilla Sjögren
- the Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
| | - Anders I. Olin
- From the Sections for Respiratory Medicine & Allergology
- Infection Medicine, Department of Clinical Sciences Lund, Lund University, University Hospital, SE-221 85 Lund, Sweden
| | - Mattias Collin
- Infection Medicine, Department of Clinical Sciences Lund, Lund University, University Hospital, SE-221 85 Lund, Sweden
| | | | - Ruth Palmer
- the Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
| | - Arne Egesten
- From the Sections for Respiratory Medicine & Allergology
| |
Collapse
|
3
|
de Zoete MR, Keestra AM, Wagenaar JA, van Putten JPM. Reconstitution of a functional Toll-like receptor 5 binding site in Campylobacter jejuni flagellin. J Biol Chem 2010; 285:12149-58. [PMID: 20164175 PMCID: PMC2852954 DOI: 10.1074/jbc.m109.070227] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Revised: 01/21/2010] [Indexed: 11/06/2022] Open
Abstract
Bacterial flagellin is important for intestinal immune homeostasis. Flagellins from most species activate Toll-like receptor 5 (TLR5). The principal bacterial food-borne pathogen Campylobacter jejuni escapes TLR5 recognition, probably due to an alternate flagellin subunit structure. We investigated the molecular basis of TLR5 evasion by aiming to reconstitute TLR5 stimulating activity in live C. jejuni. Both native glycosylated C. jejuni flagellins (FlaA and FlaB) and recombinant proteins purified from Escherichia coli failed to activate NF-kappaB in HEK293 cells expressing TLR5. Introduction of multiple defined regions from Salmonella flagellin into C. jejuni FlaA via a recombinatorial approach revealed three regions critical for the activation of human and mouse TLR5, including a beta-hairpin structure not previously implicated in TLR5 recognition. Surprisingly, this domain was not required for the activation of chicken TLR5, indicating a selective requirement for the beta-hairpin in the recognition of mammalian TLR5. Expression of the active chimeric protein in C. jejuni resulted in secreted glycosylated flagellin that induced a potent TLR5 response. Overall, our results reveal a novel structural requirement for TLR5 recognition of bacterial flagellin and exclude flagellin glycosylation as an additional mechanism of bacterial evasion of the TLR5 response.
Collapse
Affiliation(s)
- Marcel R. de Zoete
- From the Department of Infectious Diseases and Immunology, Utrecht University, P. O. Box 80.165, 3508 TD Utrecht, The Netherlands and
| | - A. Marijke Keestra
- From the Department of Infectious Diseases and Immunology, Utrecht University, P. O. Box 80.165, 3508 TD Utrecht, The Netherlands and
| | - Jaap A. Wagenaar
- From the Department of Infectious Diseases and Immunology, Utrecht University, P. O. Box 80.165, 3508 TD Utrecht, The Netherlands and
- the WHO Collaborating Centre for Campylobacter/OIE Reference Laboratory for Campylobacteriosis Utrecht/Lelystad, P.O. Box 65, 8200 AB Lelystad, The Netherlands Lelystad, The Netherlands
| | - Jos P. M. van Putten
- From the Department of Infectious Diseases and Immunology, Utrecht University, P. O. Box 80.165, 3508 TD Utrecht, The Netherlands and
- the WHO Collaborating Centre for Campylobacter/OIE Reference Laboratory for Campylobacteriosis Utrecht/Lelystad, P.O. Box 65, 8200 AB Lelystad, The Netherlands Lelystad, The Netherlands
| |
Collapse
|
4
|
Leffler J, Herbert AP, Norström E, Schmidt CQ, Barlow PN, Blom AM, Martin M. Annexin-II, DNA, and histones serve as factor H ligands on the surface of apoptotic cells. J Biol Chem 2010; 285:3766-3776. [PMID: 19951950 PMCID: PMC2823518 DOI: 10.1074/jbc.m109.045427] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [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: 07/16/2009] [Revised: 11/10/2009] [Indexed: 12/22/2022] Open
Abstract
Apoptotic cells are opsonized by complement components such as C1q and C3b, which increases their susceptibility to phagocytosis. Soluble complement inhibitors such as factor H (fH) also recognize apoptotic cells to minimize the pro-inflammatory effects of downstream complement activation. We used four radiolabeled protein constructs that span different regions of the 20 complement control protein (CCP) modules that make up fH and found that fragments comprising CCPs 6-8, CCPs 8-15, and CCPs 19-20 but not CCPs 1-4, bound to apoptotic Jurkat T cells. There are four possible ligand types on apoptotic cells that could recruit fH: proteins, carbohydrates, lipids, and DNA. We found that CCPs 6-8 of fH bind to annexin-II, a trypsin-insensitive protein that becomes exposed on surfaces of apoptotic cells. The second ligand of fH, which interacts with CCPs 6-8 and 19-20, is DNA. Confocal microscopy showed co-localization of fH with antibodies specific for DNA. fH also binds to histones devoid of DNA, and CCPs 1-4, 6-8, and 8-15 mediate this interaction. Treatment of apoptotic cells with neuraminidase, chondroitinase, heparitinase, and heparinase did not change fH binding. Treatment of apoptotic cells with phospholipase A(2) dramatically increased both binding of fH and cell-surface DNA. We also excluded the possibility that fH interacts with lysophospholipids using surface plasmon resonance and flow cytometry with lipid-coated beads. Identification of annexin-II as one of the fH ligands on apoptotic cells together with the fact that autoantibodies against annexin-II are found in systemic lupus erythematosus provides further insight into understanding the pathogenesis of this disease.
Collapse
Affiliation(s)
- Jonatan Leffler
- From the Department of Laboratory Medicine, Wallenberg Laboratory, University Hospital Malmö, Lund University, S-205 02 Malmö, Sweden and
| | - Andrew P Herbert
- the Edinburgh Biological NMR Unit, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, Scotland, United Kingdom
| | - Eva Norström
- From the Department of Laboratory Medicine, Wallenberg Laboratory, University Hospital Malmö, Lund University, S-205 02 Malmö, Sweden and
| | - Christoph Q Schmidt
- the Edinburgh Biological NMR Unit, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, Scotland, United Kingdom
| | - Paul N Barlow
- the Edinburgh Biological NMR Unit, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, Scotland, United Kingdom
| | - Anna M Blom
- From the Department of Laboratory Medicine, Wallenberg Laboratory, University Hospital Malmö, Lund University, S-205 02 Malmö, Sweden and.
| | - Myriam Martin
- From the Department of Laboratory Medicine, Wallenberg Laboratory, University Hospital Malmö, Lund University, S-205 02 Malmö, Sweden and
| |
Collapse
|
5
|
Iizasa E, Mitsutomi M, Nagano Y. Direct binding of a plant LysM receptor-like kinase, LysM RLK1/CERK1, to chitin in vitro. J Biol Chem 2010; 285:2996-3004. [PMID: 19951949 PMCID: PMC2823440 DOI: 10.1074/jbc.m109.027540] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 11/19/2009] [Indexed: 11/06/2022] Open
Abstract
Plants induce immune responses against fungal pathogens by recognition of chitin, which is a component of the fungal cell wall. Recent studies have revealed that LysM receptor-like kinase 1/chitin elicitor receptor kinase 1 (LysM RLK1/CERK1) is a critical component for the immune responses to chitin in Arabidopsis thaliana. However, the molecular mechanism of the chitin recognition by LysM RLK1 still remains unknown. Here, we present the first evidence for direct binding of LysM RLK1 to chitin. We expressed LysM RLK1 fused with yeast-enhanced green fluorescent protein (LysM RLK1-yEGFP) in yeast cells. Binding studies using the solubilized LysM RLK1-yEGFP and several insoluble polysaccharides having similar structures showed that LysM RLK1-yEGFP specifically binds to chitin. Subsequently, the fluorescence microscopic observation of the solubilized LysM RLK1-yEGFP binding to chitin beads revealed that the binding was saturable and had a high affinity, with a K(d) of approximately 82 nm. This binding was competed by the addition of soluble glycol chitin or high concentration of chitin oligosaccharides having 4-8 residues of N-acetyl glucosamine. However, the competition of these chitin oligosaccharides is weaker than that of glycol chitin. These data suggest that LysM RLK1 has a higher affinity for chitin having a longer residue of N-acetyl glucosamine. We also found that LysM RLK1-yEGFP was autophosphorylated in vitro and that chitin does not affect the phosphorylation of LysM RLK1-yEGFP. Our results provide a new dimension to chitin elicitor perception in plants.
Collapse
Affiliation(s)
- Ei'ichi Iizasa
- From the Analytical Research Center for Experimental Sciences and
- the United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan
| | - Masaru Mitsutomi
- the Department of Applied Biochemistry and Food Science, Saga University, 1 Honjo-machi, Saga 840-8502 and
- the United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan
| | - Yukio Nagano
- From the Analytical Research Center for Experimental Sciences and
- the United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan
| |
Collapse
|
6
|
Okemefuna AI, Stach L, Rana S, Ziai Buetas AJ, Gor J, Perkins SJ. C-reactive protein exists in an NaCl concentration-dependent pentamer-decamer equilibrium in physiological buffer. J Biol Chem 2010; 285:1041-52. [PMID: 19903811 PMCID: PMC2801231 DOI: 10.1074/jbc.m109.044495] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [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: 07/14/2009] [Revised: 10/28/2009] [Indexed: 11/06/2022] Open
Abstract
C-reactive protein (CRP) is an acute phase protein of the pentraxin family that binds ligands in a Ca(2+)-dependent manner, and activates complement. Knowledge of its oligomeric state in solution and at surfaces is essential for functional studies. Analytical ultracentrifugation showed that CRP in 2 mM Ca(2+) exhibits a rapid pentamer-decamer equilibrium. The proportion of decamer decreased with an increase in NaCl concentration. The sedimentation coefficients s(20,w)(0) of pentameric and decameric CRP were 6.4 S and in excess of 7.6 S, respectively. In the absence of Ca(2+), CRP partially dissociates into its protomers and the NaCl concentration dependence of the pentamer-decamer equilibrium is much reduced. By x-ray scattering, the radius of gyration R(G) values ranged from 3.7 nm for the pentamer to above 4.0 nm for the decamer. An averaged K(D) value of 21 microM in solution (140 mM NaCl, 2 mM Ca(2+)) was determined by x-ray scattering and modeling based on crystal structures for the pentamer and decamer. Surface plasmon resonance showed that CRP self-associates on a surface with immobilized CRP with a similar K(D) value of 23 microM (140 mM NaCl, 2 mM Ca(2+)), whereas CRP aggregates in low salt. It is concluded that CRP is reproducibly observed in a pentamer-decamer equilibrium in physiologically relevant concentrations both in solution and on surfaces. Both 2 mM Ca(2+) and 140 mM NaCl are essential for the integrity of CRP in functional studies and understanding the role of CRP in the acute phase response.
Collapse
Affiliation(s)
- Azubuike I. Okemefuna
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Lasse Stach
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Sudeep Rana
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Akim J. Ziai Buetas
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Jayesh Gor
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Stephen J. Perkins
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
| |
Collapse
|