1
|
de Brito BB, Lemos FFB, Carneiro CDM, Viana AS, Barreto NMPV, Assis GADS, Braga BDC, Santos MLC, Silva FAFD, Marques HS, Silva NOE, de Melo FF. Immune response to Helicobacter pylori infection and gastric cancer development. World J Meta-Anal 2021; 9:257-276. [DOI: 10.13105/wjma.v9.i3.257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/24/2021] [Accepted: 06/15/2021] [Indexed: 02/06/2023] Open
Abstract
Gastric adenocarcinoma is a global health concern, and Helicobacter pylori (H. pylori) infection is the main risk factor for its occurrence. Of note, the immune response against the pathogen seems to be a determining factor for gastric oncogenesis, and increasing evidence have emphasized several host and bacterium factors that probably influence in this setting. The development of an inflammatory process against H. pylori involves a wide range of mechanisms such as the activation of pattern recognition receptors and intracellular pathways resulting in the production of proinflammatory cytokines by gastric epithelial cells. This process culminates in the establishment of distinct immune response profiles that result from the cytokine-induced differentiation of T naïve cells into specific T helper cells. Cytokines released from each type of T helper cell orchestrate the immune system and interfere in the development of gastric cancer in idiosyncratic ways. Moreover, variants in genes such as single nucleotide polymorphisms have been associated with variable predispositions for the occurrence of gastric malignancy because they influence both the intensity of gene expression and the affinity of the resultant molecule with its receptor. In addition, various repercussions related to some H. pylori virulence factors seem to substantially influence the host immune response against the infection, and many of them have been associated with gastric tumorigenesis.
Collapse
Affiliation(s)
- Breno Bittencourt de Brito
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Fabian Fellipe Bueno Lemos
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Caroline da Mota Carneiro
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Andressa Santos Viana
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | | | | | - Barbara Dicarlo Costa Braga
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Maria Luísa Cordeiro Santos
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | | | - Hanna Santos Marques
- Campus Vitória da Conquista, Universidade Estadual do Sudoeste da Bahia, Vitória da Conquista 45031900, Bahia, Brazil
| | - Natália Oliveira e Silva
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Fabrício Freire de Melo
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| |
Collapse
|
2
|
Semper RP, Vieth M, Gerhard M, Mejías-Luque R. Helicobacter pylori Exploits the NLRC4 Inflammasome to Dampen Host Defenses. THE JOURNAL OF IMMUNOLOGY 2019; 203:2183-2193. [PMID: 31511355 DOI: 10.4049/jimmunol.1900351] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 08/07/2019] [Indexed: 02/06/2023]
Abstract
Helicobacter pylori colonizes the stomach of around 50% of humans. This chronic infection can lead to gastric pathologic conditions such as gastric ulcers and gastric adenocarcinomas. The strong inflammatory response elicited by H. pylori is characterized by the induction of the expression of several cytokines. Among those, IL-18 is found highly upregulated in infected individuals, and its expression correlates with the severity of gastric inflammation. IL-18 is produced as inactive proform and has to be cleaved by the multiprotein complex inflammasome to be active. In immune cells, the NLRC4 inflammasome, which is activated by flagellin or bacterial secretion systems, was shown to be dispensable for H. pylori-induced inflammasome activation. However, apart from immune cells, gastric epithelial cells can also produce IL-18. In this study, we analyzed the role of the NLRC4 inflammasome during H. pylori infection. Our results indicate that NLRC4 and a functional type IV secretion system are crucial for the production of IL-18 from human and murine gastric epithelial cells. In vivo, Nlrc4-/- mice failed to produce gastric IL-18 upon H. pylori infection. Compared with wild type mice, Nlrc4-/- mice controlled H. pylori better without showing strong inflammation. Moreover, H. pylori-induced IL-18 inhibits β-defensin 1 expression in a NF-κB-dependent manner, resulting in higher bacterial colonization. At the same time, inflammasome activation enhances neutrophil infiltration, resulting in inflammation. Thus, NLRC4 inflammasome activation and subsequent IL-18 production favors bacterial persistence by inhibiting antimicrobial peptide production and, at the same time, contributes to gastric inflammation.
Collapse
Affiliation(s)
- Raphaela P Semper
- Institut für Medizinische Mikrobiologie, Immunologie und Hygiene, Fakultät für Medizin, Technische Universität München, 81675 Munich, Germany; and
| | - Michael Vieth
- Institut für Pathologie, Klinikum Bayreuth, 95445 Bayreuth, Germany
| | - Markus Gerhard
- Institut für Medizinische Mikrobiologie, Immunologie und Hygiene, Fakultät für Medizin, Technische Universität München, 81675 Munich, Germany; and
| | - Raquel Mejías-Luque
- Institut für Medizinische Mikrobiologie, Immunologie und Hygiene, Fakultät für Medizin, Technische Universität München, 81675 Munich, Germany; and
| |
Collapse
|
3
|
Decreased IL-17RB expression impairs CD11b +CD11c - myeloid cell accumulation in gastric mucosa and host defense during the early-phase of Helicobacter pylori infection. Cell Death Dis 2019; 10:79. [PMID: 30692510 PMCID: PMC6349840 DOI: 10.1038/s41419-019-1312-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 12/21/2018] [Accepted: 01/04/2019] [Indexed: 12/26/2022]
Abstract
Interleukin-17 receptor B (IL-17RB), a member of the IL-17 receptor family activated by IL-17B/IL-17E, has been shown to be involved in inflammatory diseases. However, the regulation and function of IL-17RB in Helicobacter pylori (H. pylori) infection, especially in the early-phase is still unknown. Here, we found that gastric IL-17RB mRNA and protein were decreased in gastric mucosa of both patients and mice infected with H. pylori. In vitro experiments show that IL-17RB expression was down regulated via PI3K/AKT pathway on gastric epithelial cells (GECs) stimulated with H. pylori in a cagA-involved manner, while in vivo studies showed that the effect was partially dependent on cagA expression. IL-17E was also decreased during the early-phase of H. pylori infection, and provision of exogenous IL-17E resulted in increased CD11b+CD11c- myeloid cells accumulation and decreased bacteria colonization within the gastric mucosa. In the early-phase of H. pylori infection, IL-17E-IL-17RB promoted gastric epithelial cell-derived CXCL1/2/5/6 to attract CD11b+CD11c- myeloid cells, and also contributed to host defense by promoting the production of antibacterial protein Reg3a. This study defines a negative regulatory network involving IL-17E, GECs, IL-17RB, CD11b+CD11c- myeloid cells, and Reg3a in the early-phase of H. pylori infection, which results in an impaired host defense within the gastric microenvironment, suggesting IL-17RB as a potential early intervening target in H. pylori infection.
Collapse
|
4
|
Carbohydrate-Dependent and Antimicrobial Peptide Defence Mechanisms Against Helicobacter pylori Infections. Curr Top Microbiol Immunol 2019; 421:179-207. [PMID: 31123890 DOI: 10.1007/978-3-030-15138-6_8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The human stomach is a harsh and fluctuating environment for bacteria with hazards such as gastric acid and flow through of gastric contents into the intestine. H. pylori gains admission to a stable niche with nutrient access from exudates when attached to the epithelial cells under the mucus layer, whereof adherence to glycolipids and other factors provides stable and intimate attachment. To reach this niche, H. pylori must overcome mucosal defence mechanisms including the continuously secreted mucus layer, which provides several layers of defence: (1) mucins in the mucus layer can bind H. pylori and transport it away from the gastric niche with the gastric emptying, (2) mucins can inhibit H. pylori growth, both via glycans that can have antibiotic like function and via an aggregation-dependent mechanism, (3) antimicrobial peptides (AMPs) have antimicrobial activity and are retained in a strategic position in the mucus layer and (4) underneath the mucus layer, the membrane-bound mucins provide a second barrier, and can function as releasable decoys. Many of these functions are dependent on H. pylori interactions with host glycan structures, and both the host glycosylation and concentration of antimicrobial peptides change with infection and inflammation, making these interactions dynamic. Here, we review our current understanding of mucin glycan and antimicrobial peptide-dependent host defence mechanisms against H. pylori infection.
Collapse
|
5
|
Influence of Helicobacter pylori virulence factors CagA and VacA on pathogenesis of gastrointestinal disorders. Microb Pathog 2018; 117:43-48. [PMID: 29432909 DOI: 10.1016/j.micpath.2018.02.016] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 01/07/2018] [Accepted: 02/08/2018] [Indexed: 12/23/2022]
Abstract
Helicobacter Pylori (H. pylori) is a gram-negative bacteria infecting numerous people all over the world. It has been established that H. pylori play an important role in pathogenesis of gastritis, peptic ulcer and gastric cancer. Pathogenic features of this bacterium are mainly attributes to the existence of pathogenic islands (PAI) genes. The most known genes in these islands are cytotoxin-associated gene A (CagA) and vacuolating cytotoxin gene (VacA). Most studies demonstrated various frequency of CagA and VacA in patient with peptic ulcer or gastritis in different countries. This variation in CagA and VacA frequency may be due to the capability of this bacterium to be genetically versatile and can alter the expression of these genes with geographic diversity. Although H. pylori infection is not usually associated with any clinical symptoms, but sometimes leads to inflammation in gastrointestinal system and resulted in peptic ulcer and gastric cancer. In this regard, this review will illustrate the importance of Helicobacter pylori in pathogenesis of gastrointestinal disorders with focusing on CagA and VacA virulence factors.
Collapse
|
6
|
Donnarumma G, Paoletti I, Fusco A, Perfetto B, Buommino E, de Gregorio V, Baroni A. β-Defensins: Work in Progress. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 901:59-76. [DOI: 10.1007/5584_2015_5016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
7
|
Muhammad JS, Zaidi SF, Zhou Y, Sakurai H, Sugiyama T. Novel epidermal growth factor receptor pathway mediates release of human β-defensin 3 fromHelicobacter pylori-infected gastric epithelial cells. Pathog Dis 2016; 74:ftv128. [DOI: 10.1093/femspd/ftv128] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/26/2015] [Indexed: 12/11/2022] Open
|
8
|
|
9
|
Complexity of antimicrobial peptide regulation during pathogen-host interactions. Int J Antimicrob Agents 2014; 45:447-54. [PMID: 25532742 DOI: 10.1016/j.ijantimicag.2014.11.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 10/10/2014] [Accepted: 11/07/2014] [Indexed: 12/16/2022]
Abstract
Antimicrobial peptides (AMPs) are a key component of the immune system and are expressed by a large variety of organisms. AMPs are capable of eliminating a broad range of micro-organisms, illustrated by murine models where lack of AMP expression resulted in enhanced susceptibility to infection. Despite the importance of AMPs in immune defences, it is not clear whether a change in AMP expression is pathogen-specific or reflects a general response to groups of pathogens. Furthermore, it is unclear how the evoked change in AMP expression affects the host. To fully exploit the therapeutic potential of AMPs - by direct application of peptides or by using AMP-inducers - it is crucial to gain an insight into the complexity involved in pathogen-mediated regulation of AMP expression. This review summarises current knowledge on how AMP expression is affected by pathogens. In addition, the relevance and specificity of these changes in AMPs during infection will be discussed.
Collapse
|
10
|
Nuding S, Gersemann M, Hosaka Y, Konietzny S, Schaefer C, Beisner J, Schroeder BO, Ostaff MJ, Saigenji K, Ott G, Schaller M, Stange EF, Wehkamp J. Gastric antimicrobial peptides fail to eradicate Helicobacter pylori infection due to selective induction and resistance. PLoS One 2013; 8:e73867. [PMID: 24040100 PMCID: PMC3770654 DOI: 10.1371/journal.pone.0073867] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 07/31/2013] [Indexed: 12/16/2022] Open
Abstract
Background Although antimicrobial peptides protect mucus and mucosa from bacteria, Helicobacter pylori is able to colonize the gastric mucus. To clarify in which extend Helicobacter escapes the antimicrobial defense, we systematically assessed susceptibility and expression levels of different antimicrobial host factors in gastric mucosa with and without H. pylori infection. Materials and Methods We investigated the expression levels of HBD1 (gene name DEFB1), HBD2 (DEFB4A), HBD3 (DEFB103A), HBD4 (DEFB104A), LL37 (CAMP) and elafin (PI3) by real time PCR in gastric biopsy samples in a total of 20 controls versus 12 patients colonized with H. pylori. Immunostaining was performed for HBD2 and HBD3. We assessed antimicrobial susceptibility by flow cytometry, growth on blood agar, radial diffusion assay and electron microscopy. Results H. pylori infection was associated with increased gastric levels of the inducible defensin HBD2 and of the antiprotease elafin, whereas the expression levels of the constitutive defensin HBD1, inducible HBD3 and LL37 remained unchanged. HBD4 was not expressed in significant levels in gastric mucosa. H. pylori strains were resistant to the defensins HBD1 as well as to elafin, and strain specific minimally susceptible to HBD2, whereas HBD3 and LL37 killed all H. pylori strains effectively. We demonstrated the binding of HBD2 and LL37 on the surface of H. pylori cells. Comparing the antibacterial activity of extracts from H. pylori negative and positive biopsies, we found only a minimal killing against H. pylori that was not increased by the induction of HBD2 in H. pylori positive samples. Conclusion These data support the hypothesis that gastric H. pylori evades the host defense shield to allow colonization.
Collapse
Affiliation(s)
- Sabine Nuding
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology and University of Tübingen, Stuttgart, Germany
- * E-mail:
| | - Michael Gersemann
- Department of Internal Medicine I, Robert-Bosch Hospital, Stuttgart, Germany
| | - Yoshio Hosaka
- Department of Internal Medicine, Isuzu Hospital, Tokyo, Japan
| | - Sabrina Konietzny
- Department of Internal Medicine I, Robert-Bosch Hospital, Stuttgart, Germany
| | - Christian Schaefer
- Department of Internal Medicine I, Robert-Bosch Hospital, Stuttgart, Germany
| | - Julia Beisner
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology and University of Tübingen, Stuttgart, Germany
| | - Bjoern O. Schroeder
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology and University of Tübingen, Stuttgart, Germany
| | - Maureen J. Ostaff
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology and University of Tübingen, Stuttgart, Germany
| | - Katunori Saigenji
- Department of Gastroenterology, Kitasato University, Kanagawa, Japan
| | - German Ott
- Department of Clinical Pathology, Robert-Bosch Hospital, Stuttgart, Germany
| | - Martin Schaller
- Department of Dermatology, Eberhard Karls University, Tübingen, Tübingen, Germany
| | - Eduard F. Stange
- Department of Internal Medicine I, Robert-Bosch Hospital, Stuttgart, Germany
| | - Jan Wehkamp
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology and University of Tübingen, Stuttgart, Germany
- Department of Internal Medicine I, Robert-Bosch Hospital, Stuttgart, Germany
| |
Collapse
|
11
|
Patel SR, Smith K, Letley DP, Cook KW, Memon AA, Ingram RJM, Staples E, Backert S, Zaitoun AM, Atherton JC, Robinson K. Helicobacter pylori downregulates expression of human β-defensin 1 in the gastric mucosa in a type IV secretion-dependent fashion. Cell Microbiol 2013; 15:2080-92. [PMID: 23870035 PMCID: PMC4028989 DOI: 10.1111/cmi.12174] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 05/23/2013] [Accepted: 07/15/2013] [Indexed: 02/06/2023]
Abstract
Helicobacter pylori establishes a chronic lifelong infection in the human gastric mucosa, which may lead to peptic ulcer disease or gastric adenocarcinoma. The human beta-defensins (hβDs) are antimicrobial peptides, hβD1 being constitutively expressed in the human stomach. We hypothesized that H. pylori may persist, in part, by downregulating gastric hβD1 expression. We measured hβD1 and hβD2 expression in vivo in relation to the presence, density and severity of H. pylori infection, investigated differential effects of H. pylori virulence factors, and studied underlying signalling mechanisms in vitro. Significantly lower hβD1 and higher hβD2 mRNA and protein concentrations were present in gastric biopsies from infected patients. Those patients with higher-level bacterial colonization and inflammation had significantly lower hβD1 expression, but there were no differences in hβD2. H. pylori infection of human gastric epithelial cell lines also downregulated hβD1. Using wild-type strains and isogenic mutants, we showed that a functionalcag pathogenicity island-encoded type IV secretion system induced this downregulation. Treatment with chemical inhibitors or siRNA revealed that H. pylori usurped NF-κB signalling to modulate hβD1 expression. These data indicate that H. pylori downregulates hβD1 expression via NF-κB signalling, and suggest that this may promote bacterial survival and persistence in the gastric niche.
Collapse
Affiliation(s)
- S R Patel
- Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Nottingham, NG7 2RD, UK; Centre for Biomolecular Sciences, University of Nottingham, Nottingham, NG7 2RD, UK
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Bauer B, Wex T, Kuester D, Meyer T, Malfertheiner P. Differential expression of human beta defensin 2 and 3 in gastric mucosa of Helicobacter pylori-infected individuals. Helicobacter 2013; 18:6-12. [PMID: 23067102 DOI: 10.1111/hel.12000] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Antimicrobial peptides are key players of initial innate immune responses to human pathogens. Two major representatives, the human beta defensin 2 and 3 (hBD2 and hBD3), are both known to be regulated by, and to affect viability of, Helicobacter pylori. Previously, it was demonstrated in vitro that H. pylori actively abrogates hBD3 expression during prolonged infections. Here, we comprehensively assessed hBD2 and hBD3 expression ex vivo in the gastric mucosa of healthy individuals. MATERIALS AND METHODS Twenty volunteers (H. pylori positive and H. pylori negative: n = 10) were enrolled. Helicobacter pylori-positive subjects underwent eradication therapy and repeated the protocol. Expression of both defensins was assessed by quantitative RT-PCR and ELISA, and correlated with histopathologic degree of gastritis. RESULTS hBD2 and hBD3 were found to be ubiquitously expressed in all three groups. In general, hBD2 levels were elevated in relation to H. pylori infection (up to 40-fold). This upregulation correlated with degree of gastritis in corpus and antrum. In contrast, hBD3 protein levels were significantly decreased, while corresponding mRNA amounts remained unchanged. Eradication therapy led to normalization of mucosal hBD2 expression, while hBD3 expression demonstrated high interindividual variations among individuals. CONCLUSIONS Both defensins are ubiquitously but differentially expressed in gastric mucosa in relation to H. pylori infection. Ex vivo data support the notion that H. pylori infection is associated with reduced hBD3 expression in chronic active gastritis.
Collapse
Affiliation(s)
- Bianca Bauer
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Charitéplatz 1, 10117, Berlin, Germany
| | | | | | | | | |
Collapse
|
13
|
Bauer B, Pang E, Holland C, Kessler M, Bartfeld S, Meyer TF. The Helicobacter pylori virulence effector CagA abrogates human β-defensin 3 expression via inactivation of EGFR signaling. Cell Host Microbe 2012; 11:576-86. [PMID: 22704618 DOI: 10.1016/j.chom.2012.04.013] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Revised: 12/14/2011] [Accepted: 04/22/2012] [Indexed: 02/06/2023]
Abstract
Antimicrobial peptides are constituents of the first-line innate mucosal defense system that acts as a barrier to establishment of infection. The highly successful human gastric pathogen, Helicobacter pylori, is able to persistently colonize its host despite inducing expression of several antimicrobial peptides, including human β-defensin 3 (hBD3). We find that hBD3 is highly active against H. pylori in vitro and is rapidly induced during early infection via EGFR-dependent activation of MAP kinase and JAK/STAT signaling. However, during prolonged infection, hBD3 was subsequently downregulated by the H. pylori virulence determinant CagA. Upon translocation into host cells, CagA activated the cellular tyrosine phosphatase, SHP-2, terminating EGFR activation and downstream signaling and increasing bacterial viability. Chemical inhibition and knockdown of SHP-2 expression rescued hBD3 synthesis and bactericidal activity. Thus, we reveal how cagPAI-positive H. pylori strains use CagA to evade a key innate mucosal defense pathway to support the establishment of persistent infection.
Collapse
Affiliation(s)
- Bianca Bauer
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Charitéplatz 1, Berlin, Germany
| | | | | | | | | | | |
Collapse
|
14
|
Jiang Y, Yi X, Li M, Wang T, Qi T, She X. Antimicrobial activities of recombinant mouse β-defensin 3 and its synergy with antibiotics. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2012; 23:1723-1728. [PMID: 22528077 DOI: 10.1007/s10856-012-4645-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Accepted: 04/07/2012] [Indexed: 05/31/2023]
Abstract
Mammalian β-defensins are small cationic peptides of approximately 2-6 kDa that have been implicated in mediating innate immune defenses against microbial infection. This present study investigated the activity of mouse β-defensin 3 (MBD3) against bacterial and yeast drug-resistant strains in vitro, and whether this molecule acts in synergy with antibiotics. Minimum inhibitory concentrations (MICs) and minimum bactericidal/fungicidal concentrations (MBC/MFC) of recombinant MBD3 (rMBD3) were determined by microdilution assays against different strains of Staphylococcus aureus and Candida albicans. rMBD3 inhibited the growth of S. aureus (MIC, 25 μg/ml) and C. albicans (MIC, 25 μg/ml), and showed fungicidal activity against this yeast (MFC, 100 μg/ml). The influences of rMBD3 on S. aureus and C. albicans cells were examined using electron microscopy. Cells treated with rMBD3 showed morphological and structural changes, including delamination and perforation of the peripheral cell walls, porosity, and inanition of the cytoplasmic contents. Synergistic activities of rMBD3 with different antibiotics were assessed using checkerboard tests. Interestingly, the anti-methicillin-resistant S. aureus activity of rMBD3 in combination with ampicillin was synergistic; however, this was not the case against S. aureus (ATCC 25923). Combinations of rMBD3 with itraconazole, amphotericin or 5-fluorocytosine were synergistic against the two tested C. albicans strains. These results support the interest devoted to defensins as a novel class of antimicrobial agents, and highlight their abilities to potentiate the activities of conventional antibiotics.
Collapse
Affiliation(s)
- Yan Jiang
- Department of Microbiology, Guiyang Medical College, Guiyang, 550004, China.
| | | | | | | | | | | |
Collapse
|
15
|
Edwards LA, O'Neill C, Furman MA, Hicks S, Torrente F, Pérez-Machado M, Wellington EM, Phillips AD, Murch SH. Enterotoxin-producing staphylococci cause intestinal inflammation by a combination of direct epithelial cytopathy and superantigen-mediated T-cell activation. Inflamm Bowel Dis 2012; 18:624-40. [PMID: 21887731 DOI: 10.1002/ibd.21852] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 07/13/2011] [Indexed: 12/31/2022]
Abstract
BACKGROUND Enterotoxin-producing Staphylococcus aureus may cause severe inflammatory intestinal disease, particularly in infants or immunodeficient or elderly patients. They are also recognized to be associated with sudden infant death syndrome. Little is known, however, about mucosal responses to staphylococci. METHODS The mucosal lesion in three infants with staphylococcal enterocolitis was assessed by immunohistochemistry and electron microscopy. The organisms underwent extensive molecular analysis. Their toxins were assessed for capacity to induce T-cell activation and host mucosal responses examined by in vitro organ culture. Epithelial responses were studied by coculture with HEp-2 and Caco-2 cells. RESULTS Intestinal biopsies from the patients showed marked epithelial damage with mucosal inflammation. The three staphylococci, representing two distinct clones, were methicillin-sensitive, producing SEG/I enterotoxins and Rho-inactivating EDIN toxins. Their enterotoxins potently activated T cells, but only whole organisms could induce in vitro enteropathy, characterized by remarkable epithelial desquamation uninhibited by tacrolimus. EDIN-producing staphylococci, but not their supernatants, induced striking cytopathy in HEp-2 epithelial cells but not in Caco-2 cells. Although HEp-2 and Caco-2 cells produced similar IL-8, CCL20, and cathelicidin LL37 responses upon bacterial exposure, only Caco-2 cells expressed mRNA for the β-defensins HBD2 and HBD3, while HEp-2 cells were unable to do so. CONCLUSIONS Staphylococci induce enterocolitis by a combination of direct enterocyte cytopathy mediated by EDIN toxins, disrupting the epithelial barrier, and enterotoxin superantigen-induced mucosal T-cell activation. Gut epithelial production of β-defensins may contribute to host defense against invasive staphylococcal disease.
Collapse
Affiliation(s)
- Lindsey A Edwards
- Centre for Paediatric Gastroenterology Royal Free and University College Medical School, London, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Allison CC, Ferrero RL. Role of virulence factors and host cell signaling in the recognition of Helicobacter pylori and the generation of immune responses. Future Microbiol 2010; 5:1233-55. [PMID: 20722601 DOI: 10.2217/fmb.10.84] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Helicobacter pylori colonizes a large proportion of the world's population, with infection invariably leading to chronic, lifelong gastritis. While the infection often persists undiagnosed and without causing severe pathology, there are a number of host, bacterial and environmental factors that can influence whether infection provokes a mild inflammatory response or results in significant morbidity. Intriguingly, the most virulent H. pylori strains appear to deliberately induce the epithelial signaling cascades responsible for activating the innate immune system. While the reason for this remains unclear, the resulting adaptive immune responses are largely ineffective in clearing the bacterium once infection has become established and, as a result, inflammation likely causes more damage to the host itself.
Collapse
Affiliation(s)
- Cody C Allison
- Centre for Innate Immunity & Infectious Diseases, Monash Institute of Medical Research, Clayton, Australia.
| | | |
Collapse
|
17
|
Schwalfenberg GK. A review of the critical role of vitamin D in the functioning of the immune system and the clinical implications of vitamin D deficiency. Mol Nutr Food Res 2010; 55:96-108. [PMID: 20824663 DOI: 10.1002/mnfr.201000174] [Citation(s) in RCA: 230] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Revised: 07/07/2010] [Accepted: 07/09/2010] [Indexed: 12/14/2022]
Abstract
This review looks at the critical role of vitamin D in improving barrier function, production of antimicrobial peptides including cathelicidin and some defensins, and immune modulation. The function of vitamin D in the innate immune system and in the epithelial cells of the oral cavity, lung, gastrointestinal system, genito-urinary system, skin and surface of the eye is discussed. Clinical conditions are reviewed where vitamin D may play a role in the prevention of infections or where it may be used as primary or adjuvant treatment for viral, bacterial and fungal infections. Several conditions such as tuberculosis, psoriasis, eczema, Crohn's disease, chest infections, wound infections, influenza, urinary tract infections, eye infections and wound healing may benefit from adequate circulating 25(OH)D as substrate. Clinical diseases are presented in which optimization of 25(OH)D levels may benefit or cause harm according to present day knowledge. The safety of using larger doses of vitamin D in various clinical settings is discussed.
Collapse
|
18
|
Defensin-mRNA expression in the upper gastrointestinal tract is modulated in children with celiac disease and Helicobacter pylori-positive gastritis. J Pediatr Gastroenterol Nutr 2010; 50:596-600. [PMID: 20400909 DOI: 10.1097/mpg.0b013e3181cd26cd] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVES Defensins are expressed in epithelial cells as cationic peptides with antimicrobial properties. Because of their role as immunologically important effector molecules, their contribution in maintaining a stable microenvironment in the gastrointestinal tract has recently received much attention. The present study was designed to further characterize expression patterns of defensins in diseases of the upper gastrointestinal tract in children, particularly in Helicobacter pylori (Hp)-associated gastritis or celiac disease (CD). PATIENTS AND METHODS Semiquantitative real-time reverse transcriptase-polymerase chain reaction (PCR) was carried out with gene-specific primers for human beta-defensin 1 to 6 (hBD1 to 6) and human alpha-defensin 5 and 6 (hD5 and 6) in mucosal biopsies of children diagnosed as having CD (n = 11; 4.2-16.2 years) or Hp gastritis (n = 18; 3.2-16.7 years). Levels of expression were compared with those of healthy individuals (n = 21; 2.8-14.6 years). Expression levels in Hp-infected specimens were furthermore compared with those with histologic inflammation not associated with Hp infection (n = 30; 3.6-15.7 years). RESULTS Expression of hBD2 was upregulated in the antrum and corpus of patients with Hp gastritis, whereas inflammation without detection of Hp was not associated with any change in defensin gene expression. In patients with CD, expression of hBD2 was upregulated in the antrum, whereas hBD1 and 4 were downregulated in duodenal biopsies. CONCLUSIONS Different pathological conditions of the upper gastrointestinal tract lead to specific modulations of defensin gene expression in children. Especially the pathophysiological role of hBD2 in Hp infection and hBD1 and 4 in CD warrant further attention.
Collapse
|
19
|
Doss M, White MR, Tecle T, Hartshorn KL. Human defensins and LL-37 in mucosal immunity. J Leukoc Biol 2010; 87:79-92. [PMID: 19808939 PMCID: PMC7167086 DOI: 10.1189/jlb.0609382] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Revised: 09/14/2009] [Accepted: 09/15/2009] [Indexed: 12/14/2022] Open
Abstract
Defensins are widespread in nature and have activity against a broad range of pathogens. Defensins have direct antimicrobial effects and also modulate innate and adaptive immune responses. We consider the role of human defensins and the cathelicidin LL-37 in defense of respiratory, gastrointestinal, and genitourinary tracts and the oral cavity, skin, and eye. Human beta-defensins (hBDs) and human defensins 5 and 6 (HD5 and -6) are involved most obviously in mucosal responses, as they are produced principally by epithelial cells. Human alpha-defensins 1-4 (or HNPs 1-4) are produced principally by neutrophils recruited to the mucosa. Understanding the biology of defensins and LL-37 is the beginning to clarify the pathophysiology of mucosal inflammatory and infectious diseases (e.g., Crohn's disease, atopic dermatitis, lung or urinary infections). Challenges for these studies are the redundancy of innate defense mechanisms and the presence and interactions of many innate defense proteins in mucosal secretions.
Collapse
Affiliation(s)
- Mona Doss
- Boston University School of Medicine, Department of Medicine, Boston, Massachusetts, USA
| | - Mitchell R. White
- Boston University School of Medicine, Department of Medicine, Boston, Massachusetts, USA
| | - Tesfaldet Tecle
- Boston University School of Medicine, Department of Medicine, Boston, Massachusetts, USA
| | - Kevan L. Hartshorn
- Boston University School of Medicine, Department of Medicine, Boston, Massachusetts, USA
| |
Collapse
|
20
|
Grubman A, Kaparakis M, Viala J, Allison C, Badea L, Karrar A, Boneca IG, Le Bourhis L, Reeve S, Smith IA, Hartland EL, Philpott DJ, Ferrero RL. The innate immune molecule, NOD1, regulates direct killing of Helicobacter pylori by antimicrobial peptides. Cell Microbiol 2009; 12:626-39. [PMID: 20039881 DOI: 10.1111/j.1462-5822.2009.01421.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The cytosolic innate immune molecule, NOD1, recognizes peptidoglycan (PG) delivered to epithelial cells via the Helicobacter pylori cag pathogenicity island (cagPAI), and has been implicated in host defence against cagPAI(+)H. pylori bacteria. To further clarify the role of NOD1 in host defence, we investigated NOD1-dependent regulation of human beta-defensins (DEFBs) in two epithelial cell lines. Our findings identify that NOD1 activation, via either cagPAI(+) bacteria or internalized PG, was required for DEFB4 and DEFB103 expression in HEK293 cells. To investigate cell type-specific induction of DEFB4 and DEFB103, we generated stable NOD1'knockdown' (KD) and control AGS cells. Reporter gene assay and RT-PCR analyses revealed that only DEFB4 was induced in an NOD1-/cagPAI-dependent fashion in AGS cells. Moreover, culture supernatants from AGS control, but not AGS NOD1 KD cells, stimulated with cagPAI(+)H. pylori, significantly reduced H. pylori bacterial numbers. siRNA studies confirmed that human beta-defensin 2 (hBD-2), but not hBD-3, contributes to the antimicrobial activity of AGS cell supernatants against H. pylori. This study demonstrates, for the first time, the involvement of NOD1 and hBD-2 in direct killing of H. pylori bacteria by epithelial cells and confirms the importance of NOD1 in host defence mechanisms against cagPAI(+)H. pylori infection.
Collapse
Affiliation(s)
- Alexandra Grubman
- Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
The significance of E266K polymorphism in the NOD1 gene on Helicobacter Pylori infection: an effective force on pathogenesis? Clin Exp Med 2009; 10:107-12. [DOI: 10.1007/s10238-009-0077-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Accepted: 09/18/2009] [Indexed: 12/11/2022]
|
22
|
Alpha-defensin expression in the gastric tissue of children with Helicobacter pylori-associated chronic gastritis: an immunohistochemical study. J Pediatr Gastroenterol Nutr 2008; 46:474-7. [PMID: 18367969 DOI: 10.1097/mpg.0b013e31815a9923] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
In this study, we evaluated the expression of alpha-defensin and its correlation with histological criteria in children with and without Helicobacter pylori-associated gastritis. Forty-five children were included. Immunohistochemical staining was performed and the relationship between alpha-defensin immunoscoring and H. pylori status and histological criteria was evaluated. Expression of alpha-defensin was significantly higher in the H. pylori-positive group (P < 0.001) and it was significantly associated with higher grades of chronic inflammation and neutrophil density (P < 0.001 for both). Our data show that alpha-defensin expression is increased in H. pylori infection in childhood and is associated with inflammatory tissue damage.
Collapse
|
23
|
Aebischer T, Walduck A, Schroeder J, Wehrens A, Chijioke O, Schreiber S, Meyer TF. A vaccine against Helicobacter pylori: towards understanding the mechanism of protection. Int J Med Microbiol 2007; 298:161-8. [PMID: 17702653 DOI: 10.1016/j.ijmm.2007.07.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Helicobacter pylori infection remains a significant global public health problem. Vaccine development against this infection appears to be feasible but has not yet delivered its promise in clinical trials. Efforts to improve current vaccination strategies would greatly benefit from a better molecular understanding of the mechanism of protection. Here, we review recent developments in this field.
Collapse
Affiliation(s)
- Toni Aebischer
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Charité Platz 1, D-10117 Berlin, Germany
| | | | | | | | | | | | | |
Collapse
|
24
|
Robinson K, Argent RH, Atherton JC. The inflammatory and immune response to Helicobacter pylori infection. Best Pract Res Clin Gastroenterol 2007; 21:237-59. [PMID: 17382275 DOI: 10.1016/j.bpg.2007.01.001] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Lifelong Helicobacter pylori infection and its associated gastric inflammation underlie peptic ulceration and gastric carcinogenesis. The immune and inflammatory responses to H. pylori are doubly responsible: gastric inflammation is the main mediator of pathology, and the immune and inflammatory response is ineffective, allowing lifelong bacterial persistence. However, despite inducing gastric inflammation, most infections do not cause disease, and bacterial, host and environmental factors determine individual disease risk. Although H. pylori avoids many innate immune receptors, specific virulence factors (including those encoded on the cag pathogenicity island) stimulate innate immunity to increase gastric inflammation and increase disease risk. An acquired T helper 1 response upregulates local immune effectors. The extent to which environmental factors (including parasite infection), host factors and H. pylori itself influence T-helper differentiation and regulatory T-cell responses remains controversial. Finally, effective vaccines have still not been developed: a better understanding of the immune response to H. pylori may help.
Collapse
Affiliation(s)
- Karen Robinson
- Wolfson Digestive Diseases Centre, University of Nottingham, C Floor, South Block, Queen's Medical Centre Campus, Nottingham University Hospital NHS Trust, Nottingham NG7 2UH, UK.
| | | | | |
Collapse
|
25
|
Kawauchi K, Yagihashi A, Tsuji N, Uehara N, Furuya D, Kobayashi D, Watanabe N. Human β-defensin-3 induction in H pylori-infected gastric mucosal tissues. World J Gastroenterol 2006; 12:5793-7. [PMID: 17007044 PMCID: PMC4100659 DOI: 10.3748/wjg.v12.i36.5793] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To examine human β-defensin-3 (hBD-3) expression in inflamed gastric mucosal tissues or MKN45 gastric cancer cells with or without H pylori infection for better understanding the innate immune response to H pylori.
METHODS: We used reverse transcription-polymerase chain reactions and immunohistochemistry to examine hBD-3 expression in inflamed gastric mucosal tissues or MKN45 gastric cancer cells with or without H pylori. Effects of hBD-3 against H pylori were also evaluated.
RESULTS: The mean mRNA expression of hBD-3 in H pylori-positive specimens was significantly higher than that in H pylori-negative specimens (P = 0.0002, Mann-Whitney). In addition, unlike uninfected samples, 8 of 15 (53.33%) infected mucosal samples expressed hBD-3 protein. H pylori dose-dependently induced mRNA expression of hBD-3 in MKN45 cells, an effect inhibited by adding anti-toll-like receptor (TLR)-4 antibody. HBD-3 protein completely inhibited H pylori growth.
CONCLUSION: Our results suggest that like hBD-2, hBD-3 may be involved in the pathophysiology of H pylori-induced gastritis.
Collapse
Affiliation(s)
- K Kawauchi
- Department of Clinical Laboratory Medicine, Sapporo Medical University School of Medicine, South-1, West-16, Chuo-ku, Sapporo 060-8543, Japan
| | | | | | | | | | | | | |
Collapse
|
26
|
Liévin-Le Moal V, Servin AL. The front line of enteric host defense against unwelcome intrusion of harmful microorganisms: mucins, antimicrobial peptides, and microbiota. Clin Microbiol Rev 2006; 19:315-37. [PMID: 16614252 PMCID: PMC1471992 DOI: 10.1128/cmr.19.2.315-337.2006] [Citation(s) in RCA: 352] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The intestinal tract is a complex ecosystem that combines resident microbiota and the cells of various phenotypes with complex metabolic activities that line the epithelial wall. The intestinal cells that make up the epithelium provide physical and chemical barriers that protect the host against the unwanted intrusion of microorganisms that hijack the cellular molecules and signaling pathways of the host and become pathogenic. Some of the organisms making up the intestinal microbiota also have microbicidal effects that contribute to the barrier against enteric pathogens. This review describes the two cell lineages present in the intestinal epithelium: the goblet cells and the Paneth cells, both of which play a pivotal role in the first line of enteric defense by producing mucus and antimicrobial peptides, respectively. We also analyze recent insights into the intestinal microbiota and the mechanisms by which some resident species act as a barrier to enteric pathogens. Moreover, this review examines whether the cells producing mucins or antimicrobial peptides and the resident microbiota act in partnership and whether they function individually and/or synergistically to provide the host with an effective front line of defense against harmful enteric pathogens.
Collapse
Affiliation(s)
- Vanessa Liévin-Le Moal
- Unité 756 INSERM, Faculté de Pharmacie Paris XI, Signalisation et Physiopathologie des Cellules Epithéliales, Institut National de la Santé et de la Recherche Médicale, F-92296 Chātenay-Malabry, France
| | | |
Collapse
|
27
|
Hatzifoti C, Roussel Y, Harris AG, Wren BW, Morrow JW, Bajaj-Elliott M. Mucosal immunization with a urease B DNA vaccine induces innate and cellular immune responses against Helicobacter pylori. Helicobacter 2006; 11:113-22. [PMID: 16579841 DOI: 10.1111/j.1523-5378.2006.00385.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Helicobacter pylori is recognized as a major risk factor for recurrent gastroduodenal inflammatory diseases and gastric adenocarcinoma. The high prevalence of H. pylori infection worldwide, the risks of side-effects from antibiotic therapy, and increasing resistance to antibiotics are the main primers for the development of improved H. pylori vaccines. The antigenic potential of its urease enzyme, a critical virulence factor required for colonization of the gastric mucosa, has been demonstrated in animal and human studies. An important but controversial issue in H. pylori vaccine studies is the type of immune response required to control infection. A new approach in H. pylori vaccinology is the administration of DNA vaccines, which has included heat-shock protein and catalase DNA vaccines. MATERIALS AND METHODS The H. pylori urease subunit B construct or vector alone was administered to mice via the intranasal route. Spleens and stomachs were examined on day 0 and weeks 3, 6, and 12 after immunization. Proliferation of spleen cells was assessed using the carboxyfluorescein diacetate succinimidyl ester-based flow cytometry assay and cytokine secretion from cultured spleen cells was detected by ELISA, after stimulation with the urease subunit B recombinant antigen. Total RNA was isolated from stomach and spleen tissue and the expression of beta-defensin and cytokine genes was monitored by reverse transcription followed by polymerase chain reaction (RT-PCR). Immunized mice were challenged with H. pylori and bacterial DNA quantified by TaqMan PCR. RESULTS The urease B subunit DNA vaccine increased INF-gamma secretion and splenocyte proliferation without inducing adverse effects in the spleen. Increase in gastric beta-defensin 1 and marked induction in local IL-10 : IFN-gamma ratio up to 12 weeks post-immunization suggest a potential role for local innate immune responses in protection at the site of infection. Although significant bacterial reduction in the stomachs of urease B subunit DNA-immunized mice was observed, intermediate reduction was also noted in the vector group. Increased defensin expression and adjuvant effects of the cytosine preceding guanosine motifs may contribute to this phenomenon. Our data confirm that cytosine preceding guanosine motifs, even without coadministration with antigen, can reduce extracellular bacterial load. CONCLUSIONS In this study, a DNA construct encoding the urease B subunit was assessed for its immune profile and its ability to reduce bacterial colonization in the murine stomach. Our studies suggest that local innate immune responses may play a greater role than previously supposed in limiting H. pylori colonization in the gastric mucosa.
Collapse
Affiliation(s)
- Caterina Hatzifoti
- Department of Immunology, St. Bartholomew's and the Royal London School of Medicine and Dentistry, London, UK.
| | | | | | | | | | | |
Collapse
|
28
|
Boughan PK, Argent RH, Body-Malapel M, Park JH, Ewings KE, Bowie AG, Ong SJ, Cook SJ, Sorensen OE, Manzo BA, Inohara N, Klein NJ, Nuñez G, Atherton JC, Bajaj-Elliott M. Nucleotide-binding oligomerization domain-1 and epidermal growth factor receptor: critical regulators of beta-defensins during Helicobacter pylori infection. J Biol Chem 2006; 281:11637-48. [PMID: 16513653 DOI: 10.1074/jbc.m510275200] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Host-pathogen interactions that allow Helicobacter pylori to survive and persist in the stomach of susceptible individuals remain unclear. Human beta-defensins (hBDs), epithelial-derived antimicrobial peptides are critical components of host-defense at mucosal surfaces. The role of H. pylori-mediated NF-kappaB and epidermal growth factor receptor (EGFR) activation on beta-defensin expression was investigated. Transient transfection studies utilizing beta-defensin promoter constructs were conducted in gastric cells with contribution of individual signaling events evaluated by the addition of specific inhibitors, small interference nucleotide-binding oligomerization domain 1 (NOD1) RNA or plasmids encoding Vaccinia virus proteins that interrupt interleukin-1 and Toll-like receptor signaling. The role of individual MAPK pathways was further delineated in HEK-293 cells expressing conditional MAPK mutants. We found hBD2 expression exclusively dependent on the presence of the bacterial cag pathogenicity island, with NOD1 a critical host sensor. Impairment of murinebeta-defensin 4 (an orthologue of hBD2) expression in NOD1-deficient mice 7-days post-infection further confirmed the role of this cytoplasmic pattern-recognition receptor in eliciting host innate immunity. In contrast to hBD2, hBD3 expression was NOD1-independent but EGFR and ERK pathway-dependent. Importantly, Toll-like receptor signaling was not implicated in H. pylori-mediated hBD2 and hBD3 gene expression. The divergent signaling events governing hBD2 and hBD3 expression suggest temporal functional variation, such that hBD2 may contribute to antimicrobial barrier function during the inflammatory phase with hBD3 playing a greater role during the repair, wound healing phase of infection.
Collapse
Affiliation(s)
- Parjeet K Boughan
- Infectious Diseases and Microbiology Unit, Institute of Child Health, 30 Guildford St, London WC1N 1EH, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Zilbauer M, Dorrell N, Boughan PK, Harris A, Wren BW, Klein NJ, Bajaj-Elliott M. Intestinal innate immunity to Campylobacter jejuni results in induction of bactericidal human beta-defensins 2 and 3. Infect Immun 2005; 73:7281-9. [PMID: 16239524 PMCID: PMC1273837 DOI: 10.1128/iai.73.11.7281-7289.2005] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Campylobacter jejuni is the most prevalent cause of bacterial diarrhea worldwide. Despite the serious health problems caused by this bacterium, human innate immune responses to C. jejuni infection remain poorly defined. Human beta-defensins, a family of epithelial antimicrobial peptides, are a major component of host innate defense at the gastrointestinal mucosal surface. In this study, the effect of two different C. jejuni wild-type strains on human intestinal epithelial innate responses was investigated. Up-regulation of beta-defensin gene and peptide expression during infection was observed and recombinant beta-defensins were shown to have a direct bactericidal effect against C. jejuni through disruption of cell wall integrity. Further studies using an isogenic capsule-deficient mutant showed that, surprisingly, the absence of the bacterial polysaccharide capsule did not change the innate immune responses induced by C. jejuni or the ability of C. jejuni to survive exposure to recombinant beta-defensins. This study suggests a major role for this family of antimicrobial peptides in the innate immune defense against this human pathogen.
Collapse
Affiliation(s)
- Matthias Zilbauer
- Department of Infectious Diseases and Microbiology, Institute of Child Health, London WC1N 1EH, United Kingdom
| | | | | | | | | | | | | |
Collapse
|
30
|
Shen B, Porter EM, Reynoso E, Shen C, Ghosh D, Connor JT, Drazba J, Rho HK, Gramlich TL, Li R, Ormsby AH, Sy MS, Ganz T, Bevins CL. Human defensin 5 expression in intestinal metaplasia of the upper gastrointestinal tract. J Clin Pathol 2005; 58:687-94. [PMID: 15976333 PMCID: PMC1770712 DOI: 10.1136/jcp.2004.022426] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND Upper gastrointestinal tract intestinal metaplasia (IM) is termed Barrett's oesophagus (BO) or gastric intestinal metaplasia (GIM), depending on its location. BO and GIM are associated with chemical exposure resulting from gastro-oesophageal reflux and chronic Helicobacter pylori infection, respectively. Paneth cells (PCs), characterised by cytoplasmic eosinophilic granules, are found in a subset of IM at these sites, but histology may not accurately detect them. AIM To determine human defensin 5 (HD5; an antimicrobial peptide produced by PCs) expression in BO and GIM, and to investigate its association with H pylori infection. METHODS Endoscopic biopsies from 33 patients with BO and 51 with GIM, and control tissues, were examined by routine histology and for H pylori infection and HD5 mRNA and protein expression. RESULTS In normal tissues, HD5 expression was specific for PCs in the small intestine. Five patients with BE and 42 with GIM expressed HD5, but few HD5 expressing cells in IM had the characteristic histological features of PCs. Most HD5 positive specimens were H pylori infected and most HD5 negative specimens were not infected. CONCLUSIONS HD5 immunohistochemistry was often positive in IM when PCs were absent by conventional histology. Thus, HD5 immunohistochemistry may be superior to histology for identifying metaplastic PCs and distinguishing GIM from BO. The higher frequency of HD5 expression in GIM than in BO is associated with a higher frequency of H pylori infection, suggesting that in IM PCs may form part of the mucosal antibacterial response.
Collapse
Affiliation(s)
- B Shen
- Department of Gastroenterology and Hepatology, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Isomoto H, Mukae H, Ishimoto H, Nishi Y, Wen CY, Wada A, Ohnita K, Hirayama T, Nakazato M, Kohno S. High concentrations of human β-defensin 2 in gastric juice of patients with Helicobacter pylori infection. World J Gastroenterol 2005; 11:4782-7. [PMID: 16097044 PMCID: PMC4398722 DOI: 10.3748/wjg.v11.i31.4782] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: Human β-defensin (HBD)-1 and HBD-2 are endogenous antimicrobial peptides. Unlike HBD-1, the HBD-2 expression is augmented by Helicobacter pylori (H pylori). We sought to determine HBD-1 and HBD-2 concentrations in gastric juice during H pylori infection.
METHODS: HBD-1 and HBD-2 concentrations were measured by radioimmunoassay in plasma and gastric juice of 49 H pylori-infected and 33 uninfected subjects and before and after anti-H pylori treatment in 13 patients with H pylori-associated gastritis. Interleukin (IL)-1β and IL-8 concentrations in gastric juice were measured by enzyme-linked immunosorbent assay (ELISA). Histological grades of gastritis were determined using two biopsy specimens taken from the antrum and corpus. Reverse phase high performance liquid chromatography (RP-HPLC) was used to identify HBD-2.
RESULTS: HBD-2 concentrations in gastric juice, but not in plasma, were significantly higher in H pylori-positive than -negative subjects, albeit the post-treatment levels were unchanged. Immunoreactivity for HBD-2 was exclusively identified in H pylori-infected mucosa by RP-HPLC. HBD-2 concentrations in gastric juice correlated with histological degree of neutrophil and mononuclear cell infiltration in the corpus. IL-1β levels correlated with those of IL-8, but not HBD-2. Plasma and gastric juice HBD-1 concentrations were similar in H pylori-infected and uninfected subjects.
CONCLUSION: Our results place the β-defensins, especially HBD-2, in the front line of innate immune defence. Moreover, HBD-2 may be involved in the pathogenesis of H pylori-associated gastritis, possibly through its function as immune and inflammatory mediator.
Collapse
Affiliation(s)
- Hajime Isomoto
- Second Department of Internal Medicine, Nagasaki University School of Medicine, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Dommett R, Zilbauer M, George JT, Bajaj-Elliott M. Innate immune defence in the human gastrointestinal tract. Mol Immunol 2005; 42:903-12. [PMID: 15829280 DOI: 10.1016/j.molimm.2004.12.004] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The mucosal surface of the gastrointestinal tract represents a major entry point and ecological niche for many microbes. It forms an important immune barrier, absorbing nutrients, whilst preventing invasion by organisms. Of the extra-ordinarily diverse species that comprise the microbial world, relatively few organisms are able to succeed in breaching this barrier in an otherwise healthy host. The production and secretion of antimicrobial peptides (AMPs) from surface epithelia and circulating immune cells are likely to play a key role in host protection and homeostasis. A number of these peptides are constitutively produced providing resident protection, whereas others are induced during infection and inflammation. In addition to directly eradicating microorganisms, it is becoming increasingly apparent that AMPs are multi-functional with diverse immuno-modulatory properties. This review focuses on three families of AMPs, defensins, cathelicidins, and lysozyme, and discusses their role in mucosal defence.
Collapse
Affiliation(s)
- Rachel Dommett
- Infectious Diseases and Microbiology, Institute of Child Health, University of College London, 30 Guilford Street, London WC1N 1EH, UK
| | | | | | | |
Collapse
|
33
|
Nishi Y, Isomoto H, Mukae H, Ishimoto H, Wen CY, Wada A, Ohnita K, Mizuta Y, Murata I, Hirayama T, Nakazato M, Kohno S. Concentrations of α- and β-defensins in gastric juice of patients with various gastroduodenal diseases. World J Gastroenterol 2005; 11:99-103. [PMID: 15609405 PMCID: PMC4205393 DOI: 10.3748/wjg.v11.i1.99] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To determine the concentration of α- and β-defensins in gastric juice of patients with various gastroduodenal diseases.
METHODS: Concentrations of human neutrophil peptides (HNPs) 1-3, the major forms of α-defensins, and human β-defensin (HBD)-1 and HBD-2 were measured by radioimmunoassay in plasma and gastric juice of 84 subjects, consisting of 54 Helicobacter pylori-infected and 30 uninfected subjects. They included 33 patients with chronic gastritis (CG), 12 with gastric ulcer (GU), 11 with duodenal ulcer (DU), 11 with benign gastric polyp (BGP) and 16 with normal mucosa (N group) on upper endoscopy. Plasma pepsinogen I and II levels, biomarkers for gastric mucosal inflammation and atrophy, were also measured.
RESULTS: Gastric juice HNPs 1-3 levels in patients with CG, GU and BGP were significantly higher than those in patients with DU and N. Gastric juice HBD-2 concentrations in patients with CG and GU were significantly higher than those in the N group, but were significantly lower in DU patients than in GU patients. Gastric juice HBD-1 levels and plasma levels of these peptides were similar in the patient groups. Concentrations of gastric juice HNPs 1-3 and HBD-2 of in H pylori-infected patients were significantly different from those in uninfected subjects. HNPs 1-3 concentrations in gastric juice correlated negatively with plasma pepsinogen I levels and I/II ratios. HBD-2 levels in gastric juice correlated positively and negatively with plasma pepsinogen II concentrations and I/II ratios, respectively.
CONCLUSION: HNPs 1-3 and HBD-2 levels in gastric juice are diverse among various gastrointestinal diseases, reflecting the inflammatory and atrophic events of the background gastric mucosa affected by H pylori.
Collapse
Affiliation(s)
- Yoshito Nishi
- Second Department of Internal Medicine, Nagasaki University School of Medicine, Japan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|