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Williams SM, Chatterji D. Dps Functions as a Key Player in Bacterial Iron Homeostasis. ACS OMEGA 2023; 8:34299-34309. [PMID: 37779979 PMCID: PMC10536872 DOI: 10.1021/acsomega.3c03277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 08/24/2023] [Indexed: 10/03/2023]
Abstract
Iron plays a vital role in the maintenance of life, being central to various cellular processes, from respiration to gene regulation. It is essential for iron to be stored in a nontoxic and readily available form. DNA binding proteins under starvation (Dps) belong to the ferritin family of iron storage proteins and are adept at storing iron in their hollow protein shells. Existing solely in prokaryotes, these proteins have the additional functions of DNA binding and protection from oxidative stress. Iron storage proteins play a functional role in storage, release, and transfer of iron and therefore are central to the optimal functioning of iron homeostasis. Here we review the multifarious properties of Dps through relevant biochemical and structural studies with a focus on iron storage and ferroxidation. We also examine the role of Dps as a possible candidate as an iron donor to iron-sulfur (Fe-S) clusters, which are ubiquitous to many biological processes.
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Affiliation(s)
- Sunanda Margrett Williams
- Institute
of Structural and Molecular Biology, Birkbeck,
University of London, Malet Street, London WC1E
7HX, United Kingdom
| | - Dipankar Chatterji
- Molecular
Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
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2
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Fu HW, Lai YC. The Role of Helicobacter pylori Neutrophil-Activating Protein in the Pathogenesis of H. pylori and Beyond: From a Virulence Factor to Therapeutic Targets and Therapeutic Agents. Int J Mol Sci 2022; 24:ijms24010091. [PMID: 36613542 PMCID: PMC9820732 DOI: 10.3390/ijms24010091] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022] Open
Abstract
Helicobacter pylori neutrophil-activating protein (HP-NAP), a major virulence factor of H. pylori, plays a role in bacterial protection and host inflammation. HP-NAP activates a variety of innate immune cells, including neutrophils, monocytes, and mast cells, to induce their pro-oxidant and pro-inflammatory activities. This protein also induces T-helper type 1 (Th1) immune response and cytotoxic T lymphocyte (CTL) activity, supporting that HP-NAP is able to promote gastric inflammation by activation of adaptive immune responses. Thus, HP-NAP is a potential therapeutic target for the treatment of H. pylori-induced gastric inflammation. The inflammatory responses triggered by HP-NAP are mediated by a PTX-sensitive G protein-coupled receptor and Toll-like receptor 2. Drugs designed to block the interactions between HP-NAP and its receptors could alleviate the inflammation in gastric mucosa caused by H. pylori infection. In addition, HP-NAP acts as a promising therapeutic agent for vaccine development, allergy treatment, and cancer immunotherapy. The high antigenicity of HP-NAP makes this protein a component of vaccines against H. pylori infection. Due to its immunomodulatory activity to stimulate the Th1-inducing ability of dendritic cells, enhance Th1 immune response and CTL activity, and suppress Th2-mediated allergic responses, HP-NAP could also act as an adjuvant in vaccines, a drug candidate against allergic diseases, and an immunotherapeutic agent for cancer. This review highlights the role of HP-NAP in the pathogenesis of H. pylori and the potential for this protein to be a therapeutic target in the treatment of H. pylori infection and therapeutic agents against H. pylori-associated diseases, allergies, and cancer.
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Affiliation(s)
- Hua-Wen Fu
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan
- Correspondence: ; Tel.: +886-3-574-2485
| | - Yu-Chang Lai
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan
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3
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Deng R, Zheng H, Cai H, Li M, Shi Y, Ding S. Effects of helicobacter pylori on tumor microenvironment and immunotherapy responses. Front Immunol 2022; 13:923477. [PMID: 35967444 PMCID: PMC9371381 DOI: 10.3389/fimmu.2022.923477] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 07/04/2022] [Indexed: 12/13/2022] Open
Abstract
Helicobacter pylori is closely associated with gastric cancer. During persistent infection, Helicobacter pylori can form a microenvironment in gastric mucosa which facilitates the survival and colony formation of Helicobacter pylori. Tumor stromal cells are involved in this process, including tumor-associated macrophages, mesenchymal stem cells, cancer-associated fibroblasts, and myeloid-derived suppressor cells, and so on. The immune checkpoints are also regulated by Helicobacter pylori infection. Helicobacter pylori virulence factors can also act as immunogens or adjuvants to elicit or enhance immune responses, indicating their potential applications in vaccine development and tumor immunotherapy. This review highlights the effects of Helicobacter pylori on the immune microenvironment and its potential roles in tumor immunotherapy responses.
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Affiliation(s)
- Ruiyi Deng
- Peking University Third Hospital, Research Center of Clinical Epidemiology, Beijing, China
- Peking University Health Science Center, Peking University First Medical School, Beijing, China
| | - Huiling Zheng
- Peking University Third Hospital, Department of Gastroenterology, Beijing, China
| | - Hongzhen Cai
- Peking University Third Hospital, Research Center of Clinical Epidemiology, Beijing, China
- Peking University Health Science Center, Peking University First Medical School, Beijing, China
| | - Man Li
- Peking University Third Hospital, Research Center of Clinical Epidemiology, Beijing, China
- Peking University Health Science Center, Peking University Third Medical School, Beijing, China
| | - Yanyan Shi
- Peking University Third Hospital, Research Center of Clinical Epidemiology, Beijing, China
| | - Shigang Ding
- Peking University Third Hospital, Department of Gastroenterology, Beijing, China
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Codolo G, Coletta S, D’Elios MM, de Bernard M. HP-NAP of Helicobacter pylori: The Power of the Immunomodulation. Front Immunol 2022; 13:944139. [PMID: 35844568 PMCID: PMC9277015 DOI: 10.3389/fimmu.2022.944139] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 05/31/2022] [Indexed: 11/13/2022] Open
Abstract
The miniferritin HP-NAP of Helicobacter pylori was originally described as a neutrophil-activating protein because of the capacity to activate neutrophils to generate oxygen radicals and adhere to endothelia. Currently, the main feature for which HP-NAP is known is the ability to promote Th1 responses and revert the immune suppressive profile of macrophages. In this review, we discuss the immune modulating properties of the protein regarding the H. pylori infection and the evidence that support the potential clinical application of HP-NAP in allergy and cancer immunotherapy.
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Affiliation(s)
- Gaia Codolo
- Department of Biology, University of Padova, Padova, Italy
| | - Sara Coletta
- Department of Biology, University of Padova, Padova, Italy
| | - Mario Milco D’Elios
- Department of Experimental and Clinical Medicine, University of Firenze, Firenze, Italy
- *Correspondence: Marina de Bernard, ; Mario Milco D’Elios,
| | - Marina de Bernard
- Department of Biology, University of Padova, Padova, Italy
- *Correspondence: Marina de Bernard, ; Mario Milco D’Elios,
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5
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Williams SM, Chatterji D. An Overview of Dps: Dual Acting Nanovehicles in Prokaryotes with DNA Binding and Ferroxidation Properties. Subcell Biochem 2021; 96:177-216. [PMID: 33252729 DOI: 10.1007/978-3-030-58971-4_3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
DNA binding proteins under starvation (Dps) are proteins belonging to the ferritin family with the capacity for DNA binding, in addition to iron storage and ferroxidation. Present only in the prokaryotes, these multifaceted proteins have been assigned with a number of roles, from pathogenesis to nucleoid condensation and protection. They have a significant role in protecting the cells from free radical assaults, indirectly by sequestration of iron and by directly binding to the DNA. Due to their symmetry, stability and biomineralization capacity, these proteins have ever increasing potential applications in biotechnology and drug delivery. This chapter tries to bring together all these aspects of Dps in the view of current understanding and older perspectives by studies of our group as well as other experts in the field.
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Affiliation(s)
- Sunanda Margrett Williams
- Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London, WC1E 7HX, United Kingdom.
| | - Dipankar Chatterji
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India.
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Hong ZW, Yang YC, Pan T, Tzeng HF, Fu HW. Differential effects of DEAE negative mode chromatography and gel-filtration chromatography on the charge status of Helicobacter pylori neutrophil-activating protein. PLoS One 2017; 12:e0173632. [PMID: 28328957 PMCID: PMC5362085 DOI: 10.1371/journal.pone.0173632] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 02/22/2017] [Indexed: 01/19/2023] Open
Abstract
Helicobacter pylori neutrophil-activating protein (HP-NAP) is involved in H. pylori-associated gastric inflammation. HP-NAP is also a vaccine candidate, a possible drug target, and a potential diagnostic marker for H. pylori-associated diseases. Previously, we purified recombinant HP-NAP by one-step diethylaminoethyl (DEAE) negative mode chromatography by collecting the unbound fraction at pH 8.0 at 4°C. It remains unclear why HP-NAP does not bind to DEAE resins at the pH above its isoelectric point during the purification. To investigate how pH affects the surface net charge of HP-NAP and its binding to DEAE resins during the purification, recombinant HP-NAP expressed in Escherichia coli was subjected to DEAE negative mode chromatography at pH ranging from 7.0 to 9.0 at 25°C and the surface charge of purified HP-NAP was determined by capillary electrophoresis. A minimal amount of HP-NAP was detected in the elution fraction of DEAE Sepharose resin at pH 8.5, whereas recombinant HP-NAP was detected in the elution fraction of DEAE Sephadex resin only at pH 7.0 and 8.0. The purified recombinant HP-NAP obtained from the unbound fractions was not able to bind to DEAE resins at pH 7.0 to 9.0. In addition, the surface charge of the purified HP-NAP was neutral at pH 7.0 to 8.0 and was either neutral or slightly negative at pH 8.5 and 9.0. However, recombinant HP-NAP purified from gel-filtration chromatography was able to bind to DEAE Sepharose resin at pH 7.0 to 9.0 and DEAE Sephadex resin at pH 7.0. At pH 8.5 and 9.0, only the negatively charged species of HP-NAP were found. Thus, recombinant HP-NAP with different charge status can be differentially purified by DEAE negative mode chromatography and gel-filtration chromatography. Furthermore, the charge distribution on the surface of HP-NAP, the presence of impure proteins, and the overall net charge of the resins all affect the binding of HP-NAP to DEAE resins during the negative purification.
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Affiliation(s)
- Zhi-Wei Hong
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
| | - Yu-Chi Yang
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
| | - Timothy Pan
- Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
| | - Huey-Fen Tzeng
- Department of Applied Chemistry, National Chi Nan University, Puli, Nantou, Taiwan, Republic of China
- * E-mail: (HWF); (HFT)
| | - Hua-Wen Fu
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
- Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
- * E-mail: (HWF); (HFT)
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Kuo TY, Hong ZW, Tsai CC, Yang YC, Fu HW. One-step Negative Chromatographic Purification of Helicobacter pylori Neutrophil-activating Protein Overexpressed in Escherichia coli in Batch Mode. J Vis Exp 2016. [PMID: 27404433 DOI: 10.3791/54043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Helicobacter pylori neutrophil-activating protein (HP-NAP) is a major virulence factor of Helicobacter pylori (H. pylori). It plays a critical role in H. pylori-induced gastric inflammation by activating several innate leukocytes including neutrophils, monocytes, and mast cells. The immunogenic and immunomodulatory properties of HP-NAP make it a potential diagnostic and vaccine candidate for H. pylori and a new drug candidate for cancer therapy. In order to obtain substantial quantities of purified HP-NAP used for its clinical applications, an efficient method to purify this protein with high yield and purity needs to be established. In this protocol, we have described a method for one-step negative chromatographic purification of recombinant HP-NAP overexpressed in Escherichia coli (E. coli) by using diethylaminoethyl (DEAE) ion-exchange resins (e.g., Sephadex) in batch mode. Recombinant HP-NAP constitutes nearly 70% of the total protein in E. coli and is almost fully recovered in the soluble fraction upon cell lysis at pH 9.0. Under the optimal condition at pH 8.0, the majority of HP-NAP is recovered in the unbound fraction while the endogenous proteins from E. coli are efficiently removed by the resin. This purification method using negative mode batch chromatography with DEAE ion-exchange resins yields functional HP-NAP from E. coli in its native form with high yield and purity. The purified HP-NAP could be further utilized for the prevention, treatment, and prognosis of H. pylori-associated diseases as well as cancer therapy.
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Affiliation(s)
- Ting-Yu Kuo
- Institute of Molecular and Cellular Biology, National Tsing Hua University
| | - Zhi-Wei Hong
- Institute of Molecular and Cellular Biology, National Tsing Hua University
| | - Chung-Che Tsai
- Institute of Molecular and Cellular Biology, National Tsing Hua University
| | - Yu-Chi Yang
- Institute of Molecular and Cellular Biology, National Tsing Hua University
| | - Hua-Wen Fu
- Institute of Molecular and Cellular Biology, National Tsing Hua University; Department of Life Science, National Tsing Hua University;
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Shan W, Kung HF, Ge R. Comparison of Iron-Binding Ability Between Thr70-NapA and Ser70-NapA of Helicobacter pylori. Helicobacter 2016; 21:192-200. [PMID: 26347349 DOI: 10.1111/hel.12266] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND The neutrophil-activating protein (NapA) of Helicobacter pylori (H. pylori), with DNA-binding and iron seizing properties, is a fundamental virulence factor involved in H. pylori-related diseases. Compared with Ser70-NapA strain, Thr70-NapA strain is more intimately correlated with iron-deficiency anemia. METHODS To investigate whether two types of proteins differ in iron-binding ability, mutated Thr70-NapA and Ser70-NapA strains were established. Isothermal titration calorimetry (ITC) method was conducted to measure the binding between the NapA protein and Fe(2+) . The structural changes of NapA protein were also tested during iron interaction by fast protein liquid chromatography (FPLC) and circular dichroism (CD) methods. DNA-binding assay was performed for evaluate the affinity of both mutated and wild types of NapA with DNA. RESULTS Mutated Thr70-NapA had higher iron-binding ability than wild Ser70-NapA. The structural stability of Thr70-NapA was disrupted and became more active along with the rising concentration of Fe(2+) , whereas no similar association was observed between Ser70-NapA and Fe(2+) level. When the iron/protein molar ratio ranged from 10 to 20, both Ser70-NapA and Thr70-NapA displayed weaker DNA-binding ability. CONCLUSIONS Thr70-NapA has much stronger ability to sequester ferrous ion compared with Ser70-NapA in H. pylori. In addition, the DNA-binding property of NapA is dependent upon the Fe(2+) concentration.
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Affiliation(s)
- Weiran Shan
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, College of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Hsiang-Fu Kung
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - Ruiguang Ge
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, College of Life Sciences, Sun Yat-Sen University, Guangzhou, China
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Kao CY, Sheu BS, Wu JJ. Helicobacter pylori infection: An overview of bacterial virulence factors and pathogenesis. Biomed J 2016; 39:14-23. [PMID: 27105595 PMCID: PMC6138426 DOI: 10.1016/j.bj.2015.06.002] [Citation(s) in RCA: 263] [Impact Index Per Article: 32.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 06/08/2015] [Indexed: 12/16/2022] Open
Abstract
Helicobacter pylori pathogenesis and disease outcomes are mediated by a complex interplay between bacterial virulence factors, host, and environmental factors. After H. pylori enters the host stomach, four steps are critical for bacteria to establish successful colonization, persistent infection, and disease pathogenesis: (1) Survival in the acidic stomach; (2) movement toward epithelium cells by flagella-mediated motility; (3) attachment to host cells by adhesins/receptors interaction; (4) causing tissue damage by toxin release. Over the past 20 years, the understanding of H. pylori pathogenesis has been improved by studies focusing on the host and bacterial factors through epidemiology researches and molecular mechanism investigations. These include studies identifying the roles of novel virulence factors and their association with different disease outcomes, especially the bacterial adhesins, cag pathogenicity island, and vacuolating cytotoxin. Recently, the development of large-scale screening methods, including proteomic, and transcriptomic tools, has been used to determine the complex gene regulatory networks in H. pylori. In addition, a more available complete genomic database of H. pylori strains isolated from patients with different gastrointestinal diseases worldwide is helpful to characterize this bacterium. This review highlights the key findings of H. pylori virulence factors reported over the past 20 years.
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Affiliation(s)
- Cheng-Yen Kao
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Bor-Shyang Sheu
- Department of Internal Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jiunn-Jong Wu
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan; Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan, Taiwan; Department of Biotechnology and Laboratory Science in Medicine, School of Biomedical Science and Engineering, National Yang-Ming University, Taipei, Taiwan.
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Akazawa Y, Matsuda K, Isomoto H, Matsushima K, Kido Y, Urabe S, Yamaghchi N, Ohnita K, Takeshima F, Kondo H, Tsugawa H, Suzuki H, Moss J, Nakao K, Nakashima M. BH3-only protein Bim is associated with the degree of Helicobacter pylori-induced gastritis and is localized to the mitochondria of inflammatory cells in the gastric mucosa. Int J Med Microbiol 2015. [PMID: 26197709 DOI: 10.1016/j.ijmm.2015.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
BH3-only protein, Bim, is a pro-apoptotic protein that mediates mitochondria-dependent cell death. However, the role of Bim in Helicobacter pylori-associated gastritis remains unclear. This study aimed to assess the cellular localization of Bim and its possible role in H. pylori-induced gastritis. The study was conducted on biopsy specimens obtained from 80 patients who underwent upper gastrointestinal endoscopy (H. pylori-negative: n=30, positive: n=50). Association between Bim mRNA expression and severity of gastritis was evaluated and the localization of Bim was examined by immunofluorescence. Bim mRNA expression was positively correlated with the degree of gastritis, as defined by the Sydney system. Immunohistochemical analysis confirmed increased Bim expression in H. pylori-infected gastric mucosa compared with uninfected mucosa in both humans and mice. Bim localized in myeloperoxidase- and CD138-positive cells of H. pylori-infected lamina propria and submucosa of the gastric tract, indicating that this protein is predominantly expressed in neutrophils and plasma cells. In contrast, Bim did not localize in CD20-, CD3-, or CD68-positive cells. Bim was expressed in the mitochondria, where it was partially co-localized with activated Bax and cleaved-PARP. In conclusion, Bim is expressed in neutrophils and plasma cells in H. pylori-associated gastritis, where it may participate in the termination of inflammatory response by causing mitochondria-mediated apoptosis in specific leucocytes.
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Affiliation(s)
- Yuko Akazawa
- Department of Gastroenterology and Hepatology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki City, Nagasaki, 852-8501, Japan; Department of Tumor and Diagnostic Pathology, Atomic Bomb Disease Institute, 1-12-4 Sakamoto, Nagasaki City, Nagasaki, 852-8523, Japan.
| | - Katsuya Matsuda
- Department of Tumor and Diagnostic Pathology, Atomic Bomb Disease Institute, 1-12-4 Sakamoto, Nagasaki City, Nagasaki, 852-8523, Japan
| | - Hajime Isomoto
- Department of Gastroenterology and Hepatology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki City, Nagasaki, 852-8501, Japan
| | - Kayoko Matsushima
- Department of Gastroenterology and Hepatology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki City, Nagasaki, 852-8501, Japan
| | - Yoko Kido
- Department of Gastroenterology and Hepatology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki City, Nagasaki, 852-8501, Japan
| | - Shigetoshi Urabe
- Department of Gastroenterology and Hepatology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki City, Nagasaki, 852-8501, Japan
| | - Naoyuki Yamaghchi
- Department of Gastroenterology and Hepatology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki City, Nagasaki, 852-8501, Japan
| | - Ken Ohnita
- Department of Gastroenterology and Hepatology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki City, Nagasaki, 852-8501, Japan
| | - Fuminao Takeshima
- Department of Gastroenterology and Hepatology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki City, Nagasaki, 852-8501, Japan
| | - Hisayoshi Kondo
- Biostatistics Section, Division of Scientific Data Registry, Department of Radioisotope Medicine, Atomic Bomb Disease Institute, 1-12-4 Sakamoto, Nagasaki City, Nagasaki, 852-8523, Japan
| | - Hitoshi Tsugawa
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, 35 Shinano-cho, Shinjyuku-ku, Tokyo, 1600000, Japan
| | - Hidekazu Suzuki
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, 35 Shinano-cho, Shinjyuku-ku, Tokyo, 1600000, Japan
| | - Joel Moss
- Cardiovascular and Pulmonary Branch, NHLBI, National Institutes of Health, Bethesda, Maryland, United States
| | - Kazuhiko Nakao
- Department of Gastroenterology and Hepatology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki City, Nagasaki, 852-8501, Japan
| | - Masahiro Nakashima
- Department of Tumor and Diagnostic Pathology, Atomic Bomb Disease Institute, 1-12-4 Sakamoto, Nagasaki City, Nagasaki, 852-8523, Japan
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Yang YC, Kuo TY, Hong ZW, Chang HW, Chen CC, Tsai TL, Fu HW. High yield purification of Helicobacter pylori neutrophil-activating protein overexpressed in Escherichia coli. BMC Biotechnol 2015; 15:23. [PMID: 25880121 PMCID: PMC4425898 DOI: 10.1186/s12896-015-0136-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 03/18/2015] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Helicobacter pylori neutrophil-activating protein (HP-NAP) is involved in H. pylori-induced gastric inflammation. Due to its immunogenic and immunomodulatory properties, HP-NAP has been used for developing vaccines against H. pylori infection and new drugs for cancer therapy. RESULTS Here, we provide a simple process for high-yield production of HP-NAP by applying one-step negative chromatography to purify recombinant HP-NAP expressed in Escherichia coli (E. coli). In our E. coli expression system, recombinant HP-NAP constitutes nearly 70% of the total protein. Overexpressed recombinant HP-NAP is almost completely soluble upon cell lysis at pH 9.5. Under the optimal condition at pH 8.0, recombinant HP-NAP with purity higher than 95% can be obtained from E. coli by collecting the unbound fraction using diethylaminoethyl (DEAE) Sephadex resin in batch mode. The overall yield of HP-NAP from a 50-ml E. coli culture is ~19 mg. The purified HP-NAP folds into a multimer with a secondary structure of α-helix and is able to trigger the production of reactive oxygen species by neutrophils. CONCLUSIONS Purification of recombinant HP-NAP overexpressed in E. coli using DEAE Sephadex negative mode batch chromatography is an efficient method for high-yield production of highly pure HP-NAP in its native state. The purified HP-NAP is useful for various clinical applications including vaccine development, diagnosis, and new drug development.
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Affiliation(s)
- Yu-Chi Yang
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, 30013, Taiwan, Republic of China.
| | - Ting-Yu Kuo
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, 30013, Taiwan, Republic of China.
| | - Zhi-Wei Hong
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, 30013, Taiwan, Republic of China.
| | - Han-Wen Chang
- Department of Internal Medicine, Division of Hepatology and Gastroenterology, Mackay Memorial Hospital, Hsinchu, 30055, Taiwan, Republic of China.
| | - Chung-Chu Chen
- Department of Internal Medicine, Division of Hepatology and Gastroenterology, Mackay Memorial Hospital, Hsinchu, 30055, Taiwan, Republic of China.
| | - Te-Lung Tsai
- Department of Pathology and Laboratory Medicine, Mackay Memorial Hospital, Hsinchu, 30055, Taiwan, Republic of China.
| | - Hua-Wen Fu
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, 30013, Taiwan, Republic of China. .,Department of Life Science, National Tsing Hua University, Hsinchu, 30013, Taiwan, Republic of China.
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Almarza O, Núñez D, Toledo H. The DNA-binding protein HU has a regulatory role in the acid stress response mechanism in Helicobacter pylori. Helicobacter 2015; 20:29-40. [PMID: 25256909 DOI: 10.1111/hel.12171] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Bacterial genomes are compacted by association with histone-like proteins to form a complex known as bacterial chromatin. The histone-like protein HU is capable of binding and bending the DNA molecule, a function related to compaction, protection, and regulation of gene expression. In Helicobacter pylori, HU is the only histone-like protein described so far. Proteomic analysis from our laboratory showed that this protein is overexpressed under acidic stress. MATERIALS AND METHODS We used a purified recombinant wild-type protein and two mutant proteins with the amino acid substitutions K3A/S27D and K62R/V63N/P64A to characterize the function of the N-terminal domain and the flexible arm of HU. RESULTS In vitro assays for DNA protection, bending, and compaction were performed. We also designed a H. pylori hup::cat mutant strain to study the role of HU in the acid stress response. HUwt protein binds DNA and promotes its bending and compaction. Compared with the wild-type protein, both mutant proteins have less affinity for DNA and an impaired bending and compaction ability. By using qRT-PCR, we confirmed overexpression of two genes related to acid stress response (ureA and speA). Such overexpression was abolished in the hup::cat strain, which shows an acid-sensitive phenotype. CONCLUSIONS Altogether, we have shown that HUwt -DNA complex formation is favored under acidic pH and that the complex protects DNA from endonucleolytic cleavage and oxidative stress damage. We also showed that the amino-terminal domain of HU is relevant to DNA-protein complex formation and that the flexible arm of HU is involved in the bending and compaction activities of HU.
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Affiliation(s)
- Oscar Almarza
- Department of Molecular and Cellular Biology, Laboratory of Molecular Microbiology, ICBM, Faculty of Medicine, University of Chile, Avda. Independencia, 1027, Santiago, Chile
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Structures and metal-binding properties of Helicobacter pylori neutrophil-activating protein with a di-nuclear ferroxidase center. Biomolecules 2014; 4:600-15. [PMID: 24971723 PMCID: PMC4192664 DOI: 10.3390/biom4030600] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Revised: 06/03/2014] [Accepted: 06/04/2014] [Indexed: 01/24/2023] Open
Abstract
Helicobacter pylori causes severe diseases, such as chronic gastritis, peptic ulcers, and stomach cancers. H. pylori neutrophil-activating protein (HP-NAP) is an iron storage protein that forms a dodecameric shell, promotes the adhesion of neutrophils to endothelial cells, and induces the production of reactive oxygen radicals. HP-NAP belongs to the DNA-protecting proteins under starved conditions (Dps) family, which has significant structural similarities to the dodecameric ferritin family. The crystal structures of the apo form and metal-ion bound forms, such as iron, zinc, and cadmium, of HP-NAP have been determined. This review focused on the structures and metal-binding properties of HP-NAP. These metal ions bind at the di-nuclear ferroxidase center (FOC) by different coordinating patterns. In comparison with the apo structure, metal loading causes a series of conformational changes in conserved residues among HP-NAP and Dps proteins (Trp26, Asp52, and Glu56) at the FOC. HP-NAP forms a spherical dodecamer with 23 symmetry including two kinds of pores. Metal ions have been identified around one of the pores; therefore, the negatively-charged pore is suitable for the passage of metal ions.
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14
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Fu HW. Helicobacter pylori neutrophil-activating protein: From molecular pathogenesis to clinical applications. World J Gastroenterol 2014; 20:5294-5301. [PMID: 24833859 PMCID: PMC4017044 DOI: 10.3748/wjg.v20.i18.5294] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Revised: 12/02/2013] [Accepted: 01/06/2014] [Indexed: 02/06/2023] Open
Abstract
Helicobacter pylori (H. pylori) neutrophil-activating protein (HP-NAP) was originally identified as a virulence factor of H. pylori for its ability to activate neutrophils to generate respiratory burst by releasing reactive oxygen species. Later on, HP-NAP was also found to be involved in the protection of H. pylori from DNA damage, supporting the survival of H. pylori under oxidative stress. This protein is highly conserved and expressed by virtually all clinical isolates of H. pylori. The majority of patients infected with H. pylori produced antibodies specific for HP-NAP, suggesting its important role in immunity. In addition to acting as a pathogenic factor by activating the innate immunity through a wide range of human leukocytes, including neutrophils, monocytes, and mast cells, HP-NAP also mediates adaptive immunity through the induction of T helper cell type I responses. The pro-inflammatory and immunomodulatory properties of HP-NAP not only make it play an important role in disease pathogenesis but also make it a potential candidate for clinical use. Even though there is no convincing evidence to link HP-NAP to a disease outcome, recent findings supporting the pathogenic role of HP-NAP will be reviewed. In addition, the potential clinical applications of HP-NAP in vaccine development, clinical diagnosis, and drug development will be discussed.
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15
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Iankov ID, Federspiel MJ, Galanis E. Measles virus expressed Helicobacter pylori neutrophil-activating protein significantly enhances the immunogenicity of poor immunogens. Vaccine 2013; 31:4795-801. [PMID: 23948230 DOI: 10.1016/j.vaccine.2013.07.085] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 07/04/2013] [Accepted: 07/31/2013] [Indexed: 12/21/2022]
Abstract
Helicobacter pylori neutrophil-activating protein (NAP) is a toll-like receptor 2 (TLR2) agonist and potent immunomodulator inducing Th1-type immune response. Here we present data about characterization of the humoral immune response against NAP-tagged antigens, encoded by attenuated measles virus (MV) vector platform, in MV infection susceptible type I interferon receptor knockout and human CD46 transgenic (Ifnarko-CD46Ge) mice. Immunogenicity of MV expressing a full-length human immunoglobulin lambda light chain (MV-lambda) was compared to that of MV expressing lambda-NAP chimeric protein (MV-lambda-NAP). MV-lambda-NAP immunized Ifnarko-CD46Ge mice developed significantly higher (6-20-fold) anti-lambda ELISA titers as compared to the MV-lambda-immunized control animal group, indicating that covalently-linked NAP co-expression significantly enhanced lambda immunogenicity. In contrast, ELISA titers against MV antigens were not significantly different between the animals vaccinated with MV-lambda or MV-lambda-NAP. NAP-tagged antigen expression did not affect development of protective anti-measles immunity. Both MV-lambda and MV-lambda-NAP-immunized groups showed strong virus neutralization serum titers in plaque reduction microneutralization test. These results demonstrated that MV-encoded lambda-NAP is highly immunogenic as compared to the unmodified full-length lambda chain. Boost of immune response to poor immunogens using live vectors expressing NAP-tagged chimeric antigens is an attractive approach with potential application in immunoprophylaxis of infectious diseases and cancer immunotherapy.
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Affiliation(s)
- Ianko D Iankov
- Department of Molecular Medicine, Mayo Clinic, Rochester, MN 55905, USA.
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16
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An infection-enhanced oncolytic adenovirus secreting H. pylori neutrophil-activating protein with therapeutic effects on neuroendocrine tumors. Mol Ther 2013; 21:2008-18. [PMID: 23817216 PMCID: PMC3831034 DOI: 10.1038/mt.2013.153] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Accepted: 06/24/2013] [Indexed: 12/13/2022] Open
Abstract
Helicobacter pylori neutrophil-activating protein (HP-NAP) is a major virulence factor involved in H. pylori infection. HP-NAP can mediate antitumor effects by recruiting neutrophils and inducing Th1-type differentiation in the tumor microenvironment. It therefore holds strong potential as a therapeutic gene. Here, we armed a replication-selective, infection-enhanced adenovirus with secretory HP-NAP, Ad5PTDf35-[Δ24-sNAP], and evaluated its therapeutic efficacy against neuroendocrine tumors. We observed that it could specifically infect and eradicate a wide range of tumor cells lines from different origin in vitro. Insertion of secretory HP-NAP did not affect the stability or replicative capacity of the virus and infected tumor cells could efficiently secrete HP-NAP. Intratumoral administration of the virus in nude mice xenografted with neuroendocrine tumors improved median survival. Evidence of biological HP-NAP activity was observed 24 hours after treatment with neutrophil infiltration in tumors and an increase of proinflammatory cytokines such as tumor necrosis factor (TNF)-α and MIP2-α in the systemic circulation. Furthermore, evidence of Th1-type immune polarization was observed as a result of increase in IL-12/23 p40 cytokine concentrations 72 hours postvirus administration. Our observations suggest that HP-NAP can serve as a potent immunomodulator in promoting antitumor immune response in the tumor microenvironment and enhance the therapeutic effect of oncolytic adenovirus.
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17
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Shih KS, Lin CC, Hung HF, Yang YC, Wang CA, Jeng KC, Fu HW. One-step chromatographic purification of Helicobacter pylori neutrophil-activating protein expressed in Bacillus subtilis. PLoS One 2013; 8:e60786. [PMID: 23577158 PMCID: PMC3620106 DOI: 10.1371/journal.pone.0060786] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 03/02/2013] [Indexed: 12/12/2022] Open
Abstract
Helicobacter pylori neutrophil-activating protein (HP-NAP), a major virulence factor of Helicobacter pylori (H. pylori), is capable of activating human neutrophils to produce reactive oxygen species (ROS) and secrete inammatory mediators. HP-NAP is a vaccine candidate, a possible drug target, and a potential in vitro diagnostic marker for H. pylori infection. HP-NAP has also been shown to be a novel therapeutic agent for the treatment of allergic asthma and bladder cancer. Hence, an efficient way to obtain pure HP-NAP needs to be developed. In this study, one-step anion-exchange chromatography in negative mode was applied to purify the recombinant HP-NAP expressed in Bacillus subtilis (B. subtilis). This purification technique was based on the binding of host cell proteins and/or impurities other than HP-NAP to DEAE Sephadex resins. At pH 8.0, almost no other proteins except HP-NAP passed through the DEAE Sephadex column. More than 60% of the total HP-NAP with purity higher than 91% was recovered in the flow-through fraction from this single-step DEAE Sephadex chromatography. The purified recombinant HP-NAP was further demonstrated to be a multimeric protein with a secondary structure of α-helix and capable of activating human neutrophils to stimulate ROS production. Thus, this one-step negative chromatography using DEAE Sephadex resin can efficiently yield functional HP-NAP from B. subtilis in its native form with high purity. HP-NAP purified by this method could be further utilized for the development of new drugs, vaccines, and diagnostics for H. pylori infection.
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Affiliation(s)
- Kuo-Shun Shih
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
| | - Chih-Chang Lin
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
| | - Hsiao-Fang Hung
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
- Department of Medical Technology, Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli, Taiwan, Republic of China
| | - Yu-Chi Yang
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
| | - Chung-An Wang
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
| | - Kee-Ching Jeng
- Departments of Research, Taichung Veterans General Hospital, Taiwan, Republic of China
| | - Hua-Wen Fu
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
- Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
- * E-mail:
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18
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Iankov ID, Penheiter AR, Carlson SK, Galanis E. Development of monoclonal antibody-based immunoassays for detection of Helicobacter pylori neutrophil-activating protein. J Immunol Methods 2012; 384:1-9. [PMID: 22750540 DOI: 10.1016/j.jim.2012.06.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 06/19/2012] [Accepted: 06/20/2012] [Indexed: 12/15/2022]
Abstract
Neutrophil-activating protein (NAP) is a major virulence factor expressed by Helicobacter pylori isolates associated with severe chronic gastroduodenal inflammation and peptic ulcers. NAP is one of the main protective antigens and a target for vaccine development against Helicobacter infection. In addition, NAP is a potent immune stimulator with potential application as a general vaccine adjuvant and in treatment of allergic diseases and cancer immunotherapy. NAP-specific immunoassays are needed for both H. pylori diagnostics and characterization of NAP-based vaccines and immunomodulatory preparations. We generated a panel of NAP-specific monoclonal antibodies (MAbs) by immunization of BALB/c mice with synthetic NAP peptides. The antibody reactivity against recombinant or native NAP antigen was characterized by enzyme-linked immunosorbent assay (ELISA), immunoblotting and immunofluorescence. A sensitive capture ELISA was developed using MAbs 23C8 and 16F4 (directed against different NAP epitopes) for detection of native or measles virus (MV) vector-expressed recombinant NAP in a concentration range of 4 ng/ml to 2000 ng/ml. MAb 23C8 antigen-binding depends on Tyr101 in a variable amino acid sequence of the NAP molecule, indicating the existence of antigenic variants among H. pylori strains. MAb 16F4 reacted with NAP from different H. pylori strains and was a sensitive tool for detection of small amounts of isolated NAP antigen or whole bacteria by immunoblotting or immunofluorescence. In conclusion, MAb-based immunoassays are highly specific and sensitive for detection of native NAP antigen and recombinant NAP immunostimulatory transgenes expressed by replication competent virus vectors.
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Affiliation(s)
- Ianko D Iankov
- Department of Molecular Medicine, Mayo Clinic, Rochester, MN 55905, USA
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Choli-Papadopoulou T, Kottakis F, Papadopoulos G, Pendas S. Helicobacter pylori neutrophil activating protein as target for new drugs against H. pylori inflammation. World J Gastroenterol 2011; 17:2585-91. [PMID: 21677824 PMCID: PMC3110918 DOI: 10.3748/wjg.v17.i21.2585] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 02/15/2011] [Accepted: 02/22/2011] [Indexed: 02/06/2023] Open
Abstract
Helicobacter pylori (H. pylori) infection is among the most common human infections and the major risk factor for peptic ulcer disease and gastric cancer. Within this work we present the implication of C-terminal region of H. pylori neutrophil activating protein in the stimulation of neutrophil activation as well as the evidence that the C-terminal region of H. pylori activating protein is indispensable for neutrophil adhesion to endothelial cells, a step necessary to H. pylori inflammation. In addition we show that arabino galactan proteins derived from chios mastic gum, the natural resin of the plant Pistacia lentiscus var. Chia inhibit neutrophil activation in vitro.
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Iankov ID, Haralambieva IH, Galanis E. Immunogenicity of attenuated measles virus engineered to express Helicobacter pylori neutrophil-activating protein. Vaccine 2010; 29:1710-20. [PMID: 21182995 DOI: 10.1016/j.vaccine.2010.12.020] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 12/01/2010] [Accepted: 12/06/2010] [Indexed: 12/11/2022]
Abstract
Helicobacter pylori is a Gram-negative, spiral-shaped microorganism associated with acute and chronic gastritis, peptic ulcer, gastric cancer and gastric lymphomas in humans. H. pylori neutrophil-activating protein (NAP) is a major virulence factor playing a central role in pathogenesis of mucosal inflammation by immune cell attraction and Th1 cytokine response polarization. NAP is protective antigen and promising vaccine candidate against H. pylori infection. Here we present the development of measles virus (MV) vaccine strain encoding the NAP antigen. In order to facilitate the extracellular transport and detection, NAP was inserted in the human lambda immunoglobulin chain replacing a major part of the variable domain. We generated two MV vectors expressing secretory NAP forms: MV-lambda-NAP encoding the full-length constant lambda light chain domain and MV-s-NAP encoding only the N-terminus of the lambda light chain with the leader peptide. Immunization of MV permissive Ifnarko-CD46Ge transgenic mice by a single intraperitoneal injection of the NAP-expressing strains induced a robust, long-term humoral and cellular immune response against MV. Nine months post vaccination measles-neutralizing antibody titers were above the serum level considered protective for humans. Furthermore, all animals immunized with MV strains expressing the secretory NAP antigen developed strong humoral immunity against NAP, reaching titers >1:10,000 within 2-4 weeks. IFN-γ ELISpot assay confirmed that NAP-encoding MV vectors can also stimulate NAP-specific cell-mediated immunity. Our data demonstrate that MV is an excellent vector platform for expression of bacterial antigens and development of vaccines for H. pylori immunoprophylaxis in humans.
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Affiliation(s)
- Ianko D Iankov
- Department of Molecular Medicine, Mayo Clinic, Rochester, MN 55905, USA
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21
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The immune modulating activity of the Helicobacter pylori HP-NAP: Friend or foe? Toxicon 2010; 56:1186-92. [DOI: 10.1016/j.toxicon.2009.09.020] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Accepted: 09/30/2009] [Indexed: 12/20/2022]
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22
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Kottakis F, Befani C, Asiminas A, Kontou M, Koliakos G, Choli-Papadopoulou T. The C-terminal region of HPNAP activates neutrophils and promotes their adhesion to endothelial cells. Helicobacter 2009; 14:177-9. [PMID: 19702847 DOI: 10.1111/j.1523-5378.2009.00678.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Entire Helicobacter Pylori Neutrophil Activated Protein (HPNAP) and its truncated forms NH(2)-terminal region HPNAP(1-57) and C-terminal region HPNAP(58-144) after cloning into pET29c vector, purification and removal of LPS traces were subjected to human neutrophil activation. Our results revealed that the C-terminal region of HPNAP is indispensable for human neutrophil stimulation and their further adhesion to endothelial cells - a step necessary to H. pylori inflammation - in a ratio equal to that exhibited by the entire protein. In addition, experiments concerning the implication of Arabino-Galactan-Proteins (AGPs) derived from Chios Mastic Gum (CMG), the natural resin of the plant Pistacia lentiscus var. Chia revealed the inhibition of neutrophil activation and therefore their adhesion to endothelial cells, in vitro. Both, the involvement of HPNAP C-terminal region in stimulation-adhesion of neutrophils to endothelial cells as well as the inhibition of this process by AGPs have to be further investigated and may be exploited in a future anti-inflammatory therapy for H. pylori patients.
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Affiliation(s)
- Filippos Kottakis
- Laboratory of Biochemistry, School of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, Greece
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Wang CA, Liu YC, Du SY, Lin CW, Fu HW. Helicobacter pylori neutrophil-activating protein promotes myeloperoxidase release from human neutrophils. Biochem Biophys Res Commun 2008; 377:52-6. [PMID: 18823946 DOI: 10.1016/j.bbrc.2008.09.072] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Accepted: 09/12/2008] [Indexed: 12/14/2022]
Abstract
Helicobacter pylori infection induces acute and chronic inflammation and plays a key role in gastric mucosal diseases. H. pylori neutrophil-activating protein (HP-NAP), one of its virulence factors, induces not only chemotactic but also oxidative burst responses of neutrophils. Activated neutrophils use myeloperoxidase (MPO) to generate many cytotoxic oxidants, which might result in gastric mucosal injury. In this study, we evaluated whether HP-NAP could promote MPO release from human neutrophils. Recombinant HP-NAP expressed in Escherichia coli was purified by two sequential gel filtration chromatographies and then subjected to syringe filtration for endotoxin removal. The purified recombinant HP-NAP assembles into a multimer with a secondary structure of the typical alpha-helix. In addition to stimulating the production of reactive oxygen species, HP-NAP is able to induce the secretion of MPO in human neutrophils. The increased MPO release from neutrophils induced by HP-NAP may be related to the pathogenesis of H. pylori-associated gastritis.
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Affiliation(s)
- Chung-An Wang
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, ROC
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