1
|
Pudla M, Sanongkiet S, Ekchariyawat P, Luangjindarat C, Ponpuak M, Utaisincharoen P. TLR9 Negatively Regulates Intracellular Bacterial Killing by Pyroptosis in Burkholderia pseudomallei -Infected Mouse Macrophage Cell Line (Raw264.7). Microbiol Spectr 2022; 10:e0348822. [PMID: 36194127 PMCID: PMC9602866 DOI: 10.1128/spectrum.03488-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 09/15/2022] [Indexed: 01/04/2023] Open
Abstract
Melioidosis is a serious infectious disease caused by Burkholderia pseudomallei. This bacterium is able to survive and multiply inside the immune cells such as macrophages. It is well established that Toll-like receptors (TLRs), particularly surface TLRs such as TLR2, TLR4, and TLR5, play an essential role in defending against this bacterial infection. However, the involvement of endosomal TLRs in the infection has not been elucidated. In this study, we demonstrated that the number of intracellular bacteria is reduced in TLR9-depleted RAW264.7 cells infected with B. pseudomallei, suggesting that TLR9 is involved in intracellular bacterial killing in macrophages. As several reports have previously demonstrated that pyroptosis is essential for restricting intracellular bacterial killing, particularly in B. pseudomallei infection, we also observed an increased release of cytosolic enzyme lactate dehydrogenase (LDH) in TLR9-depleted cells infected with B. pseudomallei, suggesting TLR9 involvement in pyroptosis in this context. Consistently, the increases in caspase-11 and gasdermind D (GSDMD) activations, which are responsible for the LDH release, were also detected. Moreover, we demonstrated that the increases in pyroptosis and bacterial killing in B. pseudomallei-infected TLR9-depleted cells were due to the augmentation of the IFN-β, one of the key cytokines known to regulate caspase-11. Altogether, this finding showed that TLR9 suppresses macrophage killing of B. pseudomallei by regulating pyroptosis. This information provides a novel mechanism of TLR9 in the regulation of intracellular bacterial killing by macrophages, which could potentially be leveraged for therapeutic intervention. IMPORTANCE Surface TLRs have been well established to play an essential role in Burkholderia pseudomallei infection. However, the role of endosomal TLRs has not been elucidated. In the present study, we demonstrated that TLR9 plays a crucial role by negatively regulating cytokine production, particularly IFN-β, a vital cytokine to control pyroptosis via caspase-11 activation. By depletion of TLR9, the percentage of pyroptosis was significantly increased, leading to suppression of intracellular survival in B. pseudomallei-infected macrophages. These findings provide a new role of TLR9 in macrophages.
Collapse
Affiliation(s)
- Matsayapan Pudla
- Department of Oral Microbiology, Faculty of Dentistry, Mahidol University, Bangkok, Thailand
| | - Sucharat Sanongkiet
- Department of Chemistry, Faculty of Science, Silpakorn University, Nakhon Pathom, Thailand
| | - Peeraya Ekchariyawat
- Department of Microbiology, Faculty of Public Health, Mahidol University, Bangkok, Thailand
| | | | - Marisa Ponpuak
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | | |
Collapse
|
2
|
Mariappan V, Vellasamy KM, Barathan M, Girija ASS, Shankar EM, Vadivelu J. Hijacking of the Host's Immune Surveillance Radars by Burkholderia pseudomallei. Front Immunol 2021; 12:718719. [PMID: 34456925 PMCID: PMC8384953 DOI: 10.3389/fimmu.2021.718719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 07/12/2021] [Indexed: 11/20/2022] Open
Abstract
Burkholderia pseudomallei (B. pseudomallei) causes melioidosis, a potentially fatal disease for which no licensed vaccine is available thus far. The host-pathogen interactions in B. pseudomallei infection largely remain the tip of the iceberg. The pathological manifestations are protean ranging from acute to chronic involving one or more visceral organs leading to septic shock, especially in individuals with underlying conditions similar to COVID-19. Pathogenesis is attributed to the intracellular ability of the bacterium to ‘step into’ the host cell’s cytoplasm from the endocytotic vacuole, where it appears to polymerize actin filaments to spread across cells in the closer vicinity. B. pseudomallei effectively evades the host’s surveillance armory to remain latent for prolonged duration also causing relapses despite antimicrobial therapy. Therefore, eradication of intracellular B. pseudomallei is highly dependent on robust cellular immune responses. However, it remains ambiguous why certain individuals in endemic areas experience asymptomatic seroconversion, whereas others succumb to sepsis-associated sequelae. Here, we propose key insights on how the host’s surveillance radars get commandeered by B. pseudomallei.
Collapse
Affiliation(s)
- Vanitha Mariappan
- Center for Toxicology and Health Risk Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Kumutha Malar Vellasamy
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Muttiah Barathan
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - A S Smiline Girija
- Department of Microbiology, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences (SIMATS), Chennai, India
| | - Esaki M Shankar
- Infection Biology, Department of Life Sciences, Central University of Tamil Nadu, Thiruvarur, India
| | - Jamuna Vadivelu
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| |
Collapse
|
3
|
Burkholderia pseudomallei pathogenesis and survival in different niches. Biochem Soc Trans 2020; 48:569-579. [PMID: 32167134 DOI: 10.1042/bst20190836] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 01/16/2023]
Abstract
Burkholderia pseudomallei (Bp) is the causative agent of melioidosis, a disease of the tropics with high clinical mortality rates. To date, no vaccines are approved for melioidosis and current treatment relies on antibiotics. Conversely, common misdiagnosis and high pathogenicity of Bp hamper efforts to fight melioidosis. This bacterium can be isolated from a wide range of niches such as waterlogged fields, stagnant water bodies, salt water bodies and from human and animal clinical specimens. Although extensive studies have been undertaken to elucidate pathogenesis mechanisms of Bp, little is known about how a harmless soil bacterium adapts to different environmental conditions, in particular, the shift to a human host to become a highly virulent pathogen. The bacterium has a large genome encoding an armory of factors that assist the pathogen in surviving under stressful conditions and assuming its role as a deadly intracellular pathogen. This review presents an overview of what is currently known about how the pathogen adapts to different environments. With in-depth understanding of Bp adaptation and survival, more effective therapies for melioidosis can be developed by targeting related genes or proteins that play a major role in the bacteria's survival.
Collapse
|
4
|
Abstract
The causative agent of melioidosis, Burkholderia pseudomallei, a tier 1 select agent, is endemic in Southeast Asia and northern Australia, with increased incidence associated with high levels of rainfall. Increasing reports of this condition have occurred worldwide, with estimates of up to 165,000 cases and 89,000 deaths per year. The ecological niche of the organism has yet to be clearly defined, although the organism is associated with soil and water. The culture of appropriate clinical material remains the mainstay of laboratory diagnosis. Identification is best done by phenotypic methods, although mass spectrometric methods have been described. Serology has a limited diagnostic role. Direct molecular and antigen detection methods have limited availability and sensitivity. Clinical presentations of melioidosis range from acute bacteremic pneumonia to disseminated visceral abscesses and localized infections. Transmission is by direct inoculation, inhalation, or ingestion. Risk factors for melioidosis include male sex, diabetes mellitus, alcohol abuse, and immunosuppression. The organism is well adapted to intracellular survival, with numerous virulence mechanisms. Immunity likely requires innate and adaptive responses. The principles of management of this condition are drainage and debridement of infected material and appropriate antimicrobial therapy. Global mortality rates vary between 9% and 70%. Research into vaccine development is ongoing.
Collapse
Affiliation(s)
- I Gassiep
- Pathology Queensland, Townsville Hospital, Townsville, Queensland, Australia
- Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - M Armstrong
- Pathology Queensland, Townsville Hospital, Townsville, Queensland, Australia
| | - R Norton
- Pathology Queensland, Townsville Hospital, Townsville, Queensland, Australia
- Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
| |
Collapse
|
5
|
Birnie E, Claushuis TAM, Koh GCKW, Limmathurotsakul D, Day NPJ, Roelofs JJTH, Ware J, Hou B, de Vos AF, van der Poll T, van 't Veer C, Wiersinga WJ. Thrombocytopenia Impairs Host Defense Against Burkholderia pseudomallei (Melioidosis). J Infect Dis 2019; 219:648-659. [PMID: 30312422 PMCID: PMC6350952 DOI: 10.1093/infdis/jiy541] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 09/26/2018] [Indexed: 01/10/2023] Open
Abstract
Background Infection with the gram-negative bacillus Burkholderia pseudomallei (melioidosis) is an important cause of pneumosepsis in Southeast Asia and has a mortality of up to 40%. We aimed to assess the role of platelets in the host response against B. pseudomallei infection. Methods Association between platelet counts and mortality was determined in 1160 patients with culture-proven melioidosis. Mice treated with (low- or high-dose) platelet-depleting antibody were inoculated intranasally with B. pseudomallei and killed. Additional studies using functional glycoprotein Ibα-deficient mice were conducted. Results Thrombocytopenia was present in 31% of patients at admission and predicted mortality in melioidosis patients even after adjustment for confounders. In our murine-melioidosis model, platelet counts decreased, and mice treated with a platelet-depleting antibody showed enhanced mortality and higher bacterial loads compared to mice with normal platelet counts. Low platelet counts had a modest impact on early-pulmonary neutrophil influx. Reminiscent of their role in hemostasis, platelet depletion impaired vascular integrity, resulting in early lung bleeding. Glycoprotein Ibα-deficient mice had reduced platelet counts during B. pseudomallei infection together with an impaired local host defense in the lung. Conclusions Thrombocytopenia predicts mortality in melioidosis patients and, during experimental melioidosis, platelets play a protective role in both innate immunity and vascular integrity.
Collapse
Affiliation(s)
- Emma Birnie
- Center for Experimental and Molecular Medicine, Amsterdam University Medical Center (UMC), University of Amsterdam, The Netherlands
| | - Theodora A M Claushuis
- Center for Experimental and Molecular Medicine, Amsterdam University Medical Center (UMC), University of Amsterdam, The Netherlands
| | - Gavin C K W Koh
- Department of Medicine, University of Cambridge, United Kingdom
| | - Direk Limmathurotsakul
- Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, Thailand.,Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Center for Tropical Medicine and Global Health, University of Oxford, United Kingdom
| | - Nicholas P J Day
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Center for Tropical Medicine and Global Health, University of Oxford, United Kingdom
| | - Joris J T H Roelofs
- Department of Pathology, Amsterdam UMC, University of Amsterdam, The Netherlands
| | - Jerry Ware
- University of Arkansas for Medical Sciences, Little Rock
| | - Baidong Hou
- Key Laboratory of Infection and Immunity, Institute of Biophysics, Beijing, China
| | - Alex F de Vos
- Center for Experimental and Molecular Medicine, Amsterdam University Medical Center (UMC), University of Amsterdam, The Netherlands
| | - Tom van der Poll
- Center for Experimental and Molecular Medicine, Amsterdam University Medical Center (UMC), University of Amsterdam, The Netherlands.,Division of Infectious Diseases, Academic Medical Center, Amsterdam UMC, University of Amsterdam, The Netherlands
| | - Cornelis van 't Veer
- Center for Experimental and Molecular Medicine, Amsterdam University Medical Center (UMC), University of Amsterdam, The Netherlands
| | - W Joost Wiersinga
- Center for Experimental and Molecular Medicine, Amsterdam University Medical Center (UMC), University of Amsterdam, The Netherlands.,Division of Infectious Diseases, Academic Medical Center, Amsterdam UMC, University of Amsterdam, The Netherlands
| |
Collapse
|
6
|
Role of Toll-Like Receptor 5 (TLR5) in Experimental Melioidosis. Infect Immun 2019; 87:IAI.00409-18. [PMID: 31109950 DOI: 10.1128/iai.00409-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 04/26/2019] [Indexed: 12/26/2022] Open
Abstract
The Gram-negative intracellular pathogen Burkholderia pseudomallei is the causative agent of melioidosis, an important cause of sepsis in Southeast Asia. Recognition of pathogen-associated molecular patterns by Toll-like receptors (TLRs) is essential for an appropriate immune response during pathogen invasion. In patients with melioidosis, TLR5 is the most abundantly expressed TLR, and a hypofunctional TLR5 variant has been associated with improved survival. Here, we studied the functional role of TLR5 and its ligand flagellin in experimental melioidosis. First, we observed differential TLR5 expression in the pulmonary and hepatic compartments upon infection with B. pseudomallei Next, we found that B. pseudomallei-challenged TLR5-deficient (Tlr5-/- ) mice were more susceptible to infection than wild-type (WT) mice, as demonstrated by higher systemic bacterial loads, increased organ injury, and impaired survival. Lung bacterial loads were not different between the two groups. The phenotype was flagellin independent; no difference in in vivo virulence was observed for the flagellin-lacking mutant MM36 compared to the wild-type B. pseudomallei strain 1026b. Tlr5-/- mice showed a similar impaired antibacterial defense when infected with MM36 or 1026b. Ex vivo experiments showed that TLR5-deficient macrophages display markedly impaired phagocytosis of B. pseudomallei In conclusion, these data suggest that TLR5 deficiency has a detrimental flagellin-independent effect on the host response against pulmonary B. pseudomallei infection.
Collapse
|
7
|
Hu ZQ, Rao CL, Tang ML, zhang Y, Lu XX, Chen JG, Mao C, Deng L, Li Q, Mao XH. Rab32 GTPase, as a direct target of miR-30b/c, controls the intracellular survival of Burkholderia pseudomallei by regulating phagosome maturation. PLoS Pathog 2019; 15:e1007879. [PMID: 31199852 PMCID: PMC6594657 DOI: 10.1371/journal.ppat.1007879] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 06/26/2019] [Accepted: 05/30/2019] [Indexed: 02/06/2023] Open
Abstract
Burkholderia pseudomallei is a gram-negative, facultative intracellular bacterium, which causes a disease known as melioidosis. Professional phagocytes represent a crucial first line of innate defense against invading pathogens. Uptake of pathogens by these cells involves the formation of a phagosome that matures by fusing with early and late endocytic vesicles, resulting in killing of ingested microbes. Host Rab GTPases are central regulators of vesicular trafficking following pathogen phagocytosis. However, it is unclear how Rab GTPases interact with B. pseudomallei to regulate the transport and maturation of bacterial-containing phagosomes. Here, we showed that the host Rab32 plays an important role in mediating antimicrobial activity by promoting phagosome maturation at an early phase of infection with B. pseudomallei. And we demonstrated that the expression level of Rab32 is increased through the downregulation of the synthesis of miR-30b/30c in B. pseudomallei infected macrophages. Subsequently, we showed that B. pseudomallei resides temporarily in Rab32-positive compartments with late endocytic features. And Rab32 enhances phagosome acidification and promotes the fusion of B. pseudomallei-containing phagosomes with lysosomes to activate cathepsin D, resulting in restricted intracellular growth of B. pseudomallei. Additionally, Rab32 mediates phagosome maturation depending on its guanosine triphosphate/guanosine diphosphate (GTP/GDP) binding state. Finally, we report the previously unrecognized role of miR-30b/30c in regulating B. pseudomallei-containing phagosome maturation by targeting Rab32 in macrophages. Altogether, we provide a novel insight into the host immune-regulated cellular pathway against B. pseudomallei infection is partially dependent on Rab32 trafficking pathway, which regulates phagosome maturation and enhances the killing of this bacterium in macrophages.
Collapse
Affiliation(s)
- Zhi-qiang Hu
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory & Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Cheng-long Rao
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory & Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Meng-ling Tang
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory & Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Yu zhang
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory & Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Xiao-xue Lu
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory & Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Jian-gao Chen
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory & Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Chan Mao
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory & Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Ling Deng
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory & Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Qian Li
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory & Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Xu-hu Mao
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory & Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| |
Collapse
|
8
|
Lennings J, West TE, Schwarz S. The Burkholderia Type VI Secretion System 5: Composition, Regulation and Role in Virulence. Front Microbiol 2019; 9:3339. [PMID: 30687298 PMCID: PMC6335564 DOI: 10.3389/fmicb.2018.03339] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 12/24/2018] [Indexed: 12/19/2022] Open
Abstract
The soil saprophyte and Tier I select agent Burkholderia pseudomallei can cause rapidly fatal infections in humans and animals. The capability of switching to an intracellular life cycle during infection appears to be a decisive trait of B. pseudomallei for causing disease. B. pseudomallei harbors multiple type VI secretion systems (T6SSs) orthologs of which are present in the surrogate organism Burkholderia thailandensis. Upon host cell entry and vacuolar escape into the cytoplasm, B. pseudomallei and B. thailandensis manipulate host cells by utilizing the T6SS-5 (also termed T6SS1) to form multinucleated giant cells for intercellular spread. Disruption of the T6SS-5 in B. thailandensis causes a drastic attenuation of virulence in wildtype but not in mice lacking the central innate immune adapter protein MyD88. This result suggests that the T6SS-5 is deployed by the bacteria to overcome innate immune responses. However, important questions in this field remain unsolved including the mechanism underlying T6SS-5 activity and its physiological role during infection. In this review, we summarize the current knowledge on the components and regulation of the T6SS-5 as well as its role in virulence in mammalian hosts.
Collapse
Affiliation(s)
- Jan Lennings
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany
| | - T Eoin West
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Washington, Seattle, WA, United States
| | - Sandra Schwarz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany
| |
Collapse
|
9
|
Wang J, Sahoo M, Lantier L, Warawa J, Cordero H, Deobald K, Re F. Caspase-11-dependent pyroptosis of lung epithelial cells protects from melioidosis while caspase-1 mediates macrophage pyroptosis and production of IL-18. PLoS Pathog 2018; 14:e1007105. [PMID: 29791511 PMCID: PMC5988316 DOI: 10.1371/journal.ppat.1007105] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 06/05/2018] [Accepted: 05/15/2018] [Indexed: 11/18/2022] Open
Abstract
Infection with Burkholderia pseudomallei or B. thailandensis triggers activation of the NLRP3 and NLRC4 inflammasomes leading to release of IL-1β and IL-18 and death of infected macrophages by pyroptosis, respectively. The non-canonical inflammasome composed of caspase-11 is also activated by these bacteria and provides protection through induction of pyroptosis. The recent generation of bona fide caspase-1-deficient mice allowed us to reexamine in a mouse model of pneumonic melioidosis the role of caspase-1 independently of caspase-11 (that was also absent in previously generated Casp1-/- mice). Mice lacking either caspase-1 or caspase-11 were significantly more susceptible than wild type mice to intranasal infection with B. thailandensis. Absence of caspase-1 completely abolished production of IL-1β and IL-18 as well as pyroptosis of infected macrophages. In contrast, in mice lacking caspase-11 IL-1β and IL-18 were produced at normal level and macrophages pyroptosis was only marginally affected. Adoptive transfer of bone marrow indicated that caspase-11 exerted its protective action both in myeloid cells and in radio-resistant cell types. B. thailandensis was shown to readily infect mouse lung epithelial cells triggering pyroptosis in a caspase-11-dependent way in vitro and in vivo. Importantly, we show that lung epithelial cells do not express inflammasomes components or caspase-1 suggesting that this cell type relies exclusively on caspase-11 for undergoing cell death in response to bacterial infection. Finally, we show that IL-18’s protective action in melioidosis was completely dependent on its ability to induce IFNγ production. In turn, protection conferred by IFNγ against melioidosis was dependent on generation of ROS through the NADPH oxidase but independent of induction of caspase-11. Altogether, our results identify two non-redundant protective roles for caspase-1 and caspase-11 in melioidosis: Caspase-1 primarily controls pyroptosis of infected macrophages and production of IL-18. In contrast, caspase-11 mediates pyroptosis of infected lung epithelial cells. Burkholderia pseudomallei is a bacterium that infect macrophages and other cell types and causes a diseases called melioidosis. Inflammasomes are multiprotein complexes that control activation of the proteases caspase-1 and caspase-11 resulting in production of the inflammatory mediators IL-1β and IL-18 and death of infected cells. Mice deficient of caspase-1 or caspase-11 are more susceptible to infection with B. pseudomallei or the closely related B. thailandensis. Here we show that absence of caspase-1 completely abolished production of IL-1β and IL-18 as well as death of macrophages infected with B. thailandensis. In contrast, in the highly susceptible caspase-11-deficient mice, IL-1β and IL-18 production and macrophages death were not significantly affected. Rather, absence of caspase-11 abolished death of infected lung epithelial cells. Taken together, our results show that caspase-1 and caspase-11 have non-redundant protective roles in melioidosis: Caspase-1 primarily controls cell death of infected macrophages and production of IL-18. In contrast, caspase-11 mediates cell death of infected lung epithelial cells.
Collapse
Affiliation(s)
- Jinyong Wang
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America
| | - Manoranjan Sahoo
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America
| | - Louis Lantier
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America
| | - Jonathan Warawa
- Department of Microbiology and Immunology, University of Louisville, Louisville, Kentucky, United States of America
| | - Hector Cordero
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America
| | - Kelly Deobald
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America
| | - Fabio Re
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America
- * E-mail:
| |
Collapse
|
10
|
Abstract
Burkholderia pseudomallei is a Gram-negative environmental bacterium and the aetiological agent of melioidosis, a life-threatening infection that is estimated to account for ∼89,000 deaths per year worldwide. Diabetes mellitus is a major risk factor for melioidosis, and the global diabetes pandemic could increase the number of fatalities caused by melioidosis. Melioidosis is endemic across tropical areas, especially in southeast Asia and northern Australia. Disease manifestations can range from acute septicaemia to chronic infection, as the facultative intracellular lifestyle and virulence factors of B. pseudomallei promote survival and persistence of the pathogen within a broad range of cells, and the bacteria can manipulate the host's immune responses and signalling pathways to escape surveillance. The majority of patients present with sepsis, but specific clinical presentations and their severity vary depending on the route of bacterial entry (skin penetration, inhalation or ingestion), host immune function and bacterial strain and load. Diagnosis is based on clinical and epidemiological features as well as bacterial culture. Treatment requires long-term intravenous and oral antibiotic courses. Delays in treatment due to difficulties in clinical recognition and laboratory diagnosis often lead to poor outcomes and mortality can exceed 40% in some regions. Research into B. pseudomallei is increasing, owing to the biothreat potential of this pathogen and increasing awareness of the disease and its burden; however, better diagnostic tests are needed to improve early confirmation of diagnosis, which would enable better therapeutic efficacy and survival.
Collapse
Affiliation(s)
- W Joost Wiersinga
- Department of Medicine, Division of Infectious Diseases, Academic Medical Center, Meibergdreef 9, Rm. G2-132, 1105 AZ Amsterdam, The Netherlands
- Centre for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Harjeet S Virk
- Centre for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Alfredo G Torres
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Bart J Currie
- Menzies School of Health Research, Charles Darwin University and Royal Darwin Hospital, Darwin, Australia
| | - Sharon J Peacock
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
- Department of Medicine, University of Cambridge, Cambridge, UK
| | - David A B Dance
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
- Lao-Oxford-Mahosot Hospital Wellcome Trust Research Unit, Vientiane, Lao People's Democratic Republic
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Direk Limmathurotsakul
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
- Department of Tropical Hygiene and Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| |
Collapse
|
11
|
Kulsantiwong P, Pudla M, Srisaowakarn C, Boondit J, Utaisincharoen P. Pam2CSK4 and Pam3CSK4 induce iNOS expression via TBK1 and MyD88 molecules in mouse macrophage cell line RAW264.7. Inflamm Res 2017; 66:843-853. [PMID: 28593434 DOI: 10.1007/s00011-017-1063-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 04/27/2017] [Accepted: 06/02/2017] [Indexed: 12/25/2022] Open
Abstract
OBJECTIVE The aim of this study was to investigate the involvement of TLR adaptor molecules, such as TRIF, MyD88, and TBK1 in the induction of iNOS and nitric oxide (NO) production in Pam2CSK4 and Pam3CSK4-treated mouse macrophages. METHOD Mouse macrophage cell line (RAW264.7) was transfected with trif, myd88, and tbk1 siRNAs before stimulated with Pam2CSK4 and Pam3CSK4. The iNOS gene and protein expression were determined by RT-PCR and immunoblotting, respectively. The NO production was determined by Griess reaction assay. RESULTS The results showed that the induction of iNOS expression and NO production by Pam2CSK4 and Pam3CSK4 were diminished in tbk1 and myd88-depleted mouse macrophages but not trif-depleted cells. CONCLUSION These results suggested that the TBK1 and MyD88 molecules were essential for the induction of iNOS expression and NO production by both Pam2CSK4 and Pam3CSK4 via TLR2 signaling.
Collapse
Affiliation(s)
- Panthong Kulsantiwong
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Matsayapan Pudla
- Department of Oral Microbiology, Faculty of Dentistry, Mahidol University, Bangkok, Thailand
| | - Chanya Srisaowakarn
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Jitrada Boondit
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | | |
Collapse
|
12
|
Burkholderia pseudomallei Capsule Exacerbates Respiratory Melioidosis but Does Not Afford Protection against Antimicrobial Signaling or Bacterial Killing in Human Olfactory Ensheathing Cells. Infect Immun 2016; 84:1941-1956. [PMID: 27091931 DOI: 10.1128/iai.01546-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 04/03/2016] [Indexed: 02/03/2023] Open
Abstract
Melioidosis, caused by the bacterium Burkholderia pseudomallei, is an often severe infection that regularly involves respiratory disease following inhalation exposure. Intranasal (i.n.) inoculation of mice represents an experimental approach used to study the contributions of bacterial capsular polysaccharide I (CPS I) to virulence during acute disease. We used aerosol delivery of B. pseudomallei to establish respiratory infection in mice and studied CPS I in the context of innate immune responses. CPS I improved B. pseudomallei survival in vivo and triggered multiple cytokine responses, neutrophil infiltration, and acute inflammatory histopathology in the spleen, liver, nasal-associated lymphoid tissue, and olfactory mucosa (OM). To further explore the role of the OM response to B. pseudomallei infection, we infected human olfactory ensheathing cells (OECs) in vitro and measured bacterial invasion and the cytokine responses induced following infection. Human OECs killed >90% of the B. pseudomallei in a CPS I-independent manner and exhibited an antibacterial cytokine response comprising granulocyte colony-stimulating factor, tumor necrosis factor alpha, and several regulatory cytokines. In-depth genome-wide transcriptomic profiling of the OEC response by RNA-Seq revealed a network of signaling pathways activated in OECs following infection involving a novel group of 378 genes that encode biological pathways controlling cellular movement, inflammation, immunological disease, and molecular transport. This represents the first antimicrobial program to be described in human OECs and establishes the extensive transcriptional defense network accessible in these cells. Collectively, these findings show a role for CPS I in B. pseudomallei survival in vivo following inhalation infection and the antibacterial signaling network that exists in human OM and OECs.
Collapse
|
13
|
Achouiti A, de Vos AF, van ‘t Veer C, Florquin S, Tanck MW, Nawroth PP, Bierhaus A, van der Poll T, van Zoelen MAD. Receptor for Advanced Glycation End Products (RAGE) Serves a Protective Role during Klebsiella pneumoniae - Induced Pneumonia. PLoS One 2016; 11:e0141000. [PMID: 26824892 PMCID: PMC4732606 DOI: 10.1371/journal.pone.0141000] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Accepted: 10/02/2015] [Indexed: 01/01/2023] Open
Abstract
Klebsiella species is the second most commonly isolated gram-negative organism in sepsis and a frequent causative pathogen in pneumonia. The receptor for advanced glycation end products (RAGE) is expressed on different cell types and plays a key role in diverse inflammatory responses. We here aimed to investigate the role of RAGE in the host response to Klebsiella (K.) pneumoniae pneumonia and intransally inoculated rage gene deficient (RAGE-/-) and normal wild-type (Wt) mice with K. pneumoniae. Klebsiella pneumonia resulted in an increased pulmonary expression of RAGE. Furthermore, the high-affinity RAGE ligand high mobility group box-1 was upregulated during K. pneumoniae pneumonia. RAGE deficiency impaired host defense as reflected by a worsened survival, increased bacterial outgrowth and dissemination in RAGE-/- mice. RAGE-/- neutrophils showed a diminished phagocytosing capacity of live K. pneumoniae in vitro. Relative to Wt mice, RAGE-/- mice demonstrated similar lung inflammation, and slightly elevated—if any—cytokine and chemokine levels and unchanged hepatocellular injury. In addition, RAGE-/- mice displayed an unaltered response to intranasally instilled Klebsiella lipopolysaccharide (LPS) with respect to pulmonary cell recruitment and local release of cytokines and chemokines. These data suggest that (endogenous) RAGE protects against K. pneumoniae pneumonia. Also, they demonstrate that RAGE contributes to an effective antibacterial defense during K. pneumoniae pneumonia, at least partly via its participation in the phagocytic properties of professional granulocytes. Additionally, our results indicate that RAGE is not essential for the induction of a local and systemic inflammatory response to either intact Klebsiella or Klebsiella LPS.
Collapse
Affiliation(s)
- Ahmed Achouiti
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Alex F. de Vos
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Cornelis van ‘t Veer
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Sandrine Florquin
- Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Michael W. Tanck
- Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Peter P. Nawroth
- Department of Internal Medicine and Clinical Chemistry, University of Heidelberg, Heidelberg, Germany
| | - Angelika Bierhaus
- Department of Internal Medicine and Clinical Chemistry, University of Heidelberg, Heidelberg, Germany
| | - Tom van der Poll
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Marieke A. D. van Zoelen
- Laboratory of Biomedical Science, Feinstein Institute for Medical Research, North Shore Long Island University Hospital, Manhassat, New York, United States of America
- Division of Internal Medicine and Infectious Diseases, University Medical Center of Utrecht, Utrecht, the Netherlands
- Laboratory of Translational Immunology (LTI), University Medical Center of Utrecht, Utrecht, the Netherlands
- * E-mail:
| |
Collapse
|
14
|
Sahoo M, Lantier L, Re F. Role of Canonical and Non-canonical Inflammasomes During Burkholderia Infection. Curr Top Microbiol Immunol 2016; 397:199-214. [PMID: 27460811 DOI: 10.1007/978-3-319-41171-2_10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Burkholderia pseudomallei is a Gram-negative flagellate bacterium that causes melioidosis, a disease endemic to Southeast Asia and other tropical regions. Following infection of macrophages and other non-phagocytic cell types, B. pseudomallei or B. thailandensis (a related species that causes disease in mice but not humans) are able to escape the phagosome and replicate in the host cell cytoplasm. Resistance to infection with Burkholderia is dependent on the Nlrp3 and Nlrc4 inflammasomes and the non-canonical caspase-11 inflammasome. Nlrc4 mediates protection through induction of pyroptosis in the early phase of infection. As the infection progresses and as IL-18-dependent IFNγ production increases, caspase-11-dependent pyroptosis acquires a preponderant protective role. Production of IL-1β and IL-18 during infection is primarily mediated by Nlrp3. IL-18 is essential for survival because of its ability to induce IFNγ production, which in turn activates macrophage microbicidal functions and primes for caspase-11 expression. In contrast, during melioidosis, IL-1β has deleterious effects due to excessive recruitment of neutrophils to the lung and consequent tissue damage.
Collapse
Affiliation(s)
- Manoranjan Sahoo
- Department of Microbiology & Immunology, Rosalind Franklin University of Medicine and Science, 3333, Green Bay Road, North Chicago, IL, 60064, USA
| | - Louis Lantier
- Department of Microbiology & Immunology, Rosalind Franklin University of Medicine and Science, 3333, Green Bay Road, North Chicago, IL, 60064, USA
| | - Fabio Re
- Department of Microbiology & Immunology, Rosalind Franklin University of Medicine and Science, 3333, Green Bay Road, North Chicago, IL, 60064, USA.
| |
Collapse
|
15
|
Weehuizen TAF, Prior JL, van der Vaart TW, Ngugi SA, Nepogodiev SA, Field RA, Kager LM, van ‘t Veer C, de Vos AF, Wiersinga WJ. Differential Toll-Like Receptor-Signalling of Burkholderia pseudomallei Lipopolysaccharide in Murine and Human Models. PLoS One 2015; 10:e0145397. [PMID: 26689559 PMCID: PMC4687033 DOI: 10.1371/journal.pone.0145397] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 12/03/2015] [Indexed: 11/19/2022] Open
Abstract
The Gram-negative bacterium Burkholderia pseudomallei causes melioidosis and is a CDC category B bioterrorism agent. Toll-like receptor (TLR)-2 impairs host defense during pulmonary B.pseudomallei infection while TLR4 only has limited impact. We investigated the role of TLRs in B.pseudomallei-lipopolysaccharide (LPS) induced inflammation. Purified B.pseudomallei-LPS activated only TLR2-transfected-HEK-cells during short stimulation but both HEK-TLR2 and HEK-TLR4-cells after 24 h. In human blood, an additive effect of TLR2 on TLR4-mediated signalling induced by B.pseudomallei-LPS was observed. In contrast, murine peritoneal macrophages recognized B.pseudomallei-LPS solely through TLR4. Intranasal inoculation of B.pseudomallei-LPS showed that both TLR4-knockout(-/-) and TLR2x4-/-, but not TLR2-/- mice, displayed diminished cytokine responses and neutrophil influx compared to wild-type controls. These data suggest that B.pseudomallei-LPS signalling occurs solely through murine TLR4, while in human models TLR2 plays an additional role, highlighting important differences between specificity of human and murine models that may have important consequences for B.pseudomallei-LPS sensing by TLRs and subsequent susceptibility to melioidosis.
Collapse
Affiliation(s)
- Tassili A. F. Weehuizen
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
- * E-mail: (TAFW); (WJW)
| | - Joann L. Prior
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Thomas W. van der Vaart
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
| | - Sarah A. Ngugi
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | | | - Robert A. Field
- John Innes Centre, Norwich Research Park, Colney, United Kingdom
| | - Liesbeth M. Kager
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
| | - Cornelis van ‘t Veer
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
| | - Alex F. de Vos
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
| | - W. Joost Wiersinga
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
- Department of Internal Medicine, Division of Infectious Diseases, Academic Medical Center, Amsterdam, the Netherlands
- * E-mail: (TAFW); (WJW)
| |
Collapse
|
16
|
Baral P, Batra S, Zemans RL, Downey GP, Jeyaseelan S. Divergent functions of Toll-like receptors during bacterial lung infections. Am J Respir Crit Care Med 2015; 190:722-32. [PMID: 25033332 DOI: 10.1164/rccm.201406-1101pp] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Lower respiratory tract infections caused by bacteria are a major cause of death in humans irrespective of sex, race, or geography. Indeed, accumulated data indicate greater mortality and morbidity due to these infections than cancer, malaria, or HIV infection. Successful recognition of, followed by an appropriate response to, bacterial pathogens in the lungs is crucial for effective pulmonary host defense. Although the early recruitment and activation of neutrophils in the lungs is key in the response against invading microbial pathogens, other sentinels, such as alveolar macrophages, epithelial cells, dendritic cells, and CD4(+) T cells, also contribute to the elimination of the bacterial burden. Pattern recognition receptors, such as Toll-like receptors (TLRs) and nucleotide-binding oligomerization domain-like receptors, are important for recognizing and responding to microbes during pulmonary infections. However, bacterial pathogens have acquired crafty evasive strategies to circumvent the pattern recognition receptor response and thus establish infection. Increased understanding of the function of TLRs and evasive mechanisms used by pathogens during pulmonary infection will deepen our knowledge of immunopathogenesis and is crucial for developing effective therapeutic and/or prophylactic measures. This review summarizes current knowledge of the multiple roles of TLRs in bacterial lung infections and highlights the mechanisms used by pathogens to modulate or interfere with TLR signaling in the lungs.
Collapse
Affiliation(s)
- Pankaj Baral
- 1 Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
| | | | | | | | | |
Collapse
|
17
|
Cuenca AG, Joiner DN, Gentile LF, Cuenca AL, Wynn JL, Kelly-Scumpia KM, Scumpia PO, Behrns KE, Efron PA, Nacionales D, Lui C, Wallet SM, Reeves WH, Mathews CE, Moldawer LL. TRIF-dependent innate immune activation is critical for survival to neonatal gram-negative sepsis. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2015; 194:1169-77. [PMID: 25548220 PMCID: PMC4297742 DOI: 10.4049/jimmunol.1302676] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Current evidence suggests that neonatal immunity is functionally distinct from adults. Although TLR signaling through the adaptor protein, MyD88, has been shown to be critical for survival to sepsis in adults, little is known about the role of MyD88 or TRIF in neonatal sepsis. We demonstrate that TRIF(-/-) but not MyD88(-/-) neonates are highly susceptible to Escherichia coli peritonitis and bacteremia. This was associated with decreased innate immune recruitment and function. Importantly, we found that the reverse was true in adults that MyD88(-/-) but not TRIF(-/-) or wild-type adults are susceptible to E. coli peritonitis and bacteremia. In addition, we demonstrate that TRIF but not MyD88 signaling is critical for the TLR4 protective adjuvant effect we have previously demonstrated. These data suggest a differential requirement for the survival of neonates versus adults to Gram-negative infection, and that modulation of TRIF in neonates can be used to augment survival to neonatal sepsis.
Collapse
Affiliation(s)
- Alex G Cuenca
- Department of Surgery, University of Florida College of Medicine and Dentistry, Gainesville, FL 32610
| | - Dallas N Joiner
- Department of Surgery, University of Florida College of Medicine and Dentistry, Gainesville, FL 32610
| | - Lori F Gentile
- Department of Surgery, University of Florida College of Medicine and Dentistry, Gainesville, FL 32610
| | - Angela L Cuenca
- Department of Surgery, University of Florida College of Medicine and Dentistry, Gainesville, FL 32610
| | - James L Wynn
- Division of Neonatology, Department of Pediatrics Vanderbilt University, Nashville, TN 37232
| | - Kindra M Kelly-Scumpia
- Department of Surgery, University of Florida College of Medicine and Dentistry, Gainesville, FL 32610
| | - Philip O Scumpia
- Department of Surgery, University of Florida College of Medicine and Dentistry, Gainesville, FL 32610
| | - Kevin E Behrns
- Department of Surgery, University of Florida College of Medicine and Dentistry, Gainesville, FL 32610
| | - Philip A Efron
- Department of Surgery, University of Florida College of Medicine and Dentistry, Gainesville, FL 32610
| | - Dina Nacionales
- Department of Surgery, University of Florida College of Medicine and Dentistry, Gainesville, FL 32610
| | - Chao Lui
- Department of Pathology, University of Florida College of Medicine and Dentistry, Gainesville, FL 32610
| | - Shannon M Wallet
- University of Florida College of Medicine and Dentistry, Gainesville, FL 32610; and
| | - Westley H Reeves
- Department of Medicine, University of Florida College of Medicine and Dentistry, Gainesville, FL 32610
| | - Clayton E Mathews
- Department of Pathology, University of Florida College of Medicine and Dentistry, Gainesville, FL 32610
| | - Lyle L Moldawer
- Department of Surgery, University of Florida College of Medicine and Dentistry, Gainesville, FL 32610;
| |
Collapse
|
18
|
Abstract
OBJECTIVES Streptococcus pneumoniae is the most common causative organism in community-acquired pneumonia responsible for millions of deaths every year. DNAX-activating protein of 12 kDa is an adaptor molecule for different myeloid expressed receptors involved in innate immunity. DESIGN Animal study. SETTING University research laboratory. SUBJECTS DNAX-activating protein of 12 kDa-deficient (dap12) and wild-type mice. INTERVENTIONS Mice were intranasally infected with S. pneumoniae. In addition, ex vivo responsiveness of alveolar macrophages was examined. MEASUREMENTS AND MAIN RESULTS dap12 alveolar macrophages released more tumor necrosis factor-α upon stimulation with S. pneumoniae and displayed increased phagocytosis of this pathogen compared with wild-type cells. After infection with S. pneumoniae via the airways, dap12 mice demonstrated reduced bacterial outgrowth in the lungs together with delayed dissemination to distant body sites relative to wild-type mice. This favorable response in dap12 mice was accompanied by reduced lung inflammation and an improved survival. CONCLUSIONS These data suggest that DNAX-activating protein of 12 kDa impairs host defense during pneumococcal pneumonia at the primary site of infection at least in part by inhibiting phagocytosis by alveolar macrophages.
Collapse
|
19
|
Alam S, Amemiya K, Bernhards RC, Ulrich RG, Waag DM, Saikh KU. Characterization of cellular immune response and innate immune signaling in human and nonhuman primate primary mononuclear cells exposed to Burkholderia mallei. Microb Pathog 2014; 78:20-8. [PMID: 25450887 DOI: 10.1016/j.micpath.2014.11.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 11/14/2014] [Accepted: 11/18/2014] [Indexed: 10/24/2022]
Abstract
Burkholderia pseudomallei infection causes melioidosis and is often characterized by severe sepsis. Although rare in humans, Burkholderia mallei has caused infections in laboratory workers, and the early innate cellular response to B. mallei in human and nonhuman primates has not been characterized. In this study, we examined the primary cellular immune response to B. mallei in PBMC cultures of non-human primates (NHPs), Chlorocebus aethiops (African Green Monkeys), Macaca fascicularis (Cynomolgus macaque), and Macaca mulatta (Rhesus macaque) and humans. Our results demonstrated that B. mallei elicited strong primary pro-inflammatory cytokines (IFN-γ, TNF-α, IL-1β, and IL-6) equivalent to the levels of B. pseudomallei in primary PBMC cultures of NHPs and humans. When we examined IL-1β and other cytokine responses by comparison to Escherichia coli LPS, African Green Monkeys appears to be most responsive to B. mallei than Cynomolgus or Rhesus. Characterization of the immune signaling mechanism for cellular response was conducted by using a ligand induced cell-based reporter assay, and our results demonstrated that MyD88 mediated signaling contributed to the B. mallei and B. pseudomallei induced pro-inflammatory responses. Notably, the induced reporter activity with B. mallei, B. pseudomallei, or purified LPS from these pathogens was inhibited and cytokine production was attenuated by a MyD88 inhibitor. Together, these results show that in the scenario of severe hyper-inflammatory responses to B. mallei infection, MyD88 targeted therapeutic intervention may be a successful strategy for therapy.
Collapse
Affiliation(s)
- Shahabuddin Alam
- Department of Immunology, Army Medical Research Institute of Infectious Diseases, Frederick, MD, USA
| | - Kei Amemiya
- Department of Bacteriology, Army Medical Research Institute of Infectious Diseases, Frederick, MD, USA
| | - Robert C Bernhards
- Department of Bacteriology, Army Medical Research Institute of Infectious Diseases, Frederick, MD, USA
| | - Robert G Ulrich
- Department of Immunology, Army Medical Research Institute of Infectious Diseases, Frederick, MD, USA
| | - David M Waag
- Department of Bacteriology, Army Medical Research Institute of Infectious Diseases, Frederick, MD, USA
| | - Kamal U Saikh
- Department of Immunology, Army Medical Research Institute of Infectious Diseases, Frederick, MD, USA.
| |
Collapse
|
20
|
Hematopoietic but not endothelial cell MyD88 contributes to host defense during gram-negative pneumonia derived sepsis. PLoS Pathog 2014; 10:e1004368. [PMID: 25254554 PMCID: PMC4177915 DOI: 10.1371/journal.ppat.1004368] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Accepted: 07/31/2014] [Indexed: 12/12/2022] Open
Abstract
Klebsiella pneumoniae is an important cause of sepsis. The common Toll-like receptor adapter myeloid differentiation primary response gene (MyD)88 is crucial for host defense against Klebsiella. Here we investigated the role of MyD88 in myeloid and endothelial cells during Klebsiella pneumosepsis. Mice deficient for MyD88 in myeloid (LysM-Myd88(-/-)) and myeloid plus endothelial (Tie2-Myd88(-/-)) cells showed enhanced lethality and bacterial growth. Tie2-Myd88(-/-) mice reconstituted with control bone marrow, representing mice with a selective MyD88 deficiency in endothelial cells, showed an unremarkable antibacterial defense. Myeloid or endothelial cell MyD88 deficiency did not impact on lung pathology or distant organ injury during late stage sepsis, while LysM-Myd88(-/-) mice demonstrated a strongly attenuated inflammatory response in the airways early after infection. These data suggest that myeloid but not endothelial MyD88 is important for host defense during gram-negative pneumonia derived sepsis.
Collapse
|
21
|
West TE, Myers ND, Chantratita N, Chierakul W, Limmathurotsakul D, Wuthiekanun V, Miao EA, Hajjar AM, Peacock SJ, Liggitt HD, Skerrett SJ. NLRC4 and TLR5 each contribute to host defense in respiratory melioidosis. PLoS Negl Trop Dis 2014; 8:e3178. [PMID: 25232720 PMCID: PMC4169243 DOI: 10.1371/journal.pntd.0003178] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 08/09/2014] [Indexed: 02/02/2023] Open
Abstract
Burkholderia pseudomallei causes the tropical infection melioidosis. Pneumonia is a common manifestation of melioidosis and is associated with high mortality. Understanding the key elements of host defense is essential to developing new therapeutics for melioidosis. As a flagellated bacterium encoding type III secretion systems, B. pseudomallei may trigger numerous host pathogen recognition receptors. TLR5 is a flagellin sensor located on the plasma membrane. NLRC4, along with NAIP proteins, assembles a canonical caspase-1-dependent inflammasome in the cytoplasm that responds to flagellin (in mice) and type III secretion system components (in mice and humans). In a murine model of respiratory melioidosis, Tlr5 and Nlrc4 each contributed to survival. Mice deficient in both Tlr5 and Nlrc4 were not more susceptible than single knockout animals. Deficiency of Casp1/Casp11 resulted in impaired bacterial control in the lung and spleen; in the lung much of this effect was attributable to Nlrc4, despite relative preservation of pulmonary IL-1β production in Nlrc4−/− mice. Histologically, deficiency of Casp1/Casp11 imparted more severe pulmonary inflammation than deficiency of Nlrc4. The human NLRC4 region polymorphism rs6757121 was associated with survival in melioidosis patients with pulmonary involvement. Co-inheritance of rs6757121 and a functional TLR5 polymorphism had an additive effect on survival. Our results show that NLRC4 and TLR5, key components of two flagellin sensing pathways, each contribute to host defense in respiratory melioidosis. Melioidosis is an infection caused by Burkholderia pseudomallei, a bacterium that is found in tropical soil and water. Melioidosis can present in a variety of ways, but lung involvement is common and usually severe. The host response to infection governs outcome. In this study, we examined the role of two host sensors of bacterial components–TLR5 and NLRC4–to determine their necessity in respiratory melioidosis. Although both proteins are involved in detection of bacterial flagellin, in mice we defined specific and individual roles for TLR5 and NLRC4 in protecting against death from melioidosis. In humans with melioidosis involving the lung, genetic variation in these receptors also had independent associations with survival. These results underscore the importance of these elements of host defense in respiratory melioidosis and support further studies of the underlying mechanisms.
Collapse
Affiliation(s)
- T. Eoin West
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, United States of America
- International Respiratory and Severe Illness Center, University of Washington, Seattle, Washington, United States of America
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- * E-mail:
| | - Nicolle D. Myers
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Narisara Chantratita
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Wirongrong Chierakul
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Direk Limmathurotsakul
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Vanaporn Wuthiekanun
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Edward A. Miao
- Department of Microbiology and Immunology, Lineberger Comprehensive Cancer Center, and Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Adeline M. Hajjar
- Department of Comparative Medicine, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Sharon J. Peacock
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - H. Denny Liggitt
- Department of Comparative Medicine, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Shawn J. Skerrett
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, United States of America
| |
Collapse
|
22
|
de Jong HK, Koh GC, Achouiti A, van der Meer AJ, Bulder I, Stephan F, Roelofs JJ, Day NP, Peacock SJ, Zeerleder S, Wiersinga WJ. Neutrophil extracellular traps in the host defense against sepsis induced by Burkholderia pseudomallei (melioidosis). Intensive Care Med Exp 2014. [PMID: 26215706 PMCID: PMC4678137 DOI: 10.1186/s40635-014-0021-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Background Neutrophil extracellular traps (NETs) are a central player in the host response to bacteria: neutrophils release extracellular DNA (nucleosomes) and neutrophil elastase to entrap and kill bacteria. We studied the role of NETs in Burkholderia pseudomallei infection (melioidosis), an important cause of Gram-negative sepsis in Southeast Asia. Methods In a prospective observational study, circulating nucleosomes and neutrophil elastase were assayed in 44 patients with Gram-negative sepsis caused by B. pseudomallei (melioidosis) and 82 controls. Functional assays included human neutrophil stimulation and killing assays and a murine model of B. pseudomallei infection in which NET function was compromised using DNase. Specified pathogen-free 8- to 12-week-old C57BL/6 mice were sacrificed post-infection to assess bacterial loads, inflammation, and pathology. Results Nucleosome and neutrophil elastase levels were markedly elevated in patients compared to controls. NETs killed B. pseudomallei effectively, and neutrophils stimulated with B. pseudomallei showed increased elastase and DNA release in a time- and dose-dependent matter. In mice, NET disruption with intravenous DNase administration resulted in decreased nucleosome levels. Although DNase treatment of mice resulted in diminished liver inflammation, no differences were observed in bacterial dissemination or systemic inflammation. Conclusion B. pseudomallei is a potent inducer of NETosis which was reflected by greatly increased levels of NET-related components in melioidosis patients. Although NETs exhibited antibacterial activity against B. pseudomallei, NET formation did not protect against bacterial dissemination and inflammation during B. pseudomallei-induced sepsis. Electronic supplementary material The online version of this article (doi:10.1186/s40635-014-0021-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Hanna K de Jong
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Meibergdreef 9, Room G2-132, Amsterdam, 1105 AZ, The Netherlands,
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
CpG oligodeoxynucleotide protect neonatal piglets from challenge with the enterotoxigenic E. coli. Vet Immunol Immunopathol 2014; 161:66-76. [PMID: 25081388 DOI: 10.1016/j.vetimm.2014.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 07/02/2014] [Accepted: 07/06/2014] [Indexed: 11/23/2022]
Abstract
CpG motifs activates mammalian lymphocytes and macrophages to produce cytokines and polyclonal Ig. These include IFN-γ, IL-12, TNF-a, which are important in the control of bacterial infection. But thus far, the innate immunostimulatory effects of CpG ODN against pathogen have been established mainly in mouse, monkey, sheep, chicken, but not in neonatal piglets. The purpose of this study is to determine the potential protection of CpG ODN against enterotoxigenic Escherichia coli (ETEC) (with which neonatal piglets were susceptible to infection in our lab) in neonatal piglets. Here, we show intranasal (IN)-mucosal and intramuscularly (IM) systemic administration of CpG ODN could enhance innate cellular (cytokine) immunity in the sera and intestine mucosa post challenge, and thereafter the development of antigen-specific antibodies in piglets. IN and IM immunizations of neonatal piglets without antigen both reduced the ETEC excretion and alleviated diarrhoea symptoms upon challenge, and IN route had better protection effects than IM route. Protection in this study was linked to induction of a Th1 response which induced by CpG ODN. Co-delivery with Emulsigen (EM), could improve protection mediated by CpG ODN. These observations indicate that IN administration of 100 μg/kg CpG ODN with 20% EM codelivery may represent a valuable strategy for induction of innate immunity against ETEC infection in neonatal piglets.
Collapse
|
24
|
Kager LM, van der Poll T, Wiersinga WJ. The coagulation system in melioidosis: from pathogenesis to new treatment strategies. Expert Rev Anti Infect Ther 2014; 12:993-1002. [PMID: 24962103 DOI: 10.1586/14787210.2014.928198] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Melioidosis, caused by the Gram-negative bacterium Burkholderia pseudomallei, is a dreadful disease common in South-East Asia and Northern Australia and is characterized by chronic suppurative lesions and pneumonia. Melioidosis may evolve into severe sepsis with multi-organ failure with high mortalities, despite proper antibiotic therapy. Besides activation of a strong pro-inflammatory host response, the coagulation system plays an important role during melioidosis, which is thought to be host-protective. In particular, a procoagulant state together with downregulation of anticoagulant pathways and activation of fibrinolysis are present, all closely interrelated with parameters of inflammation. This review presents an overview of recent studies in which the role of coagulation, anti-coagulation and fibrinolysis during melioidosis was investigated both in patients and in experimental settings.
Collapse
Affiliation(s)
- Liesbeth Martine Kager
- Academic Medical Center, Center for Experimental and Molecular Medicine (CEMM), University of Amsterdam, Meibergdreef 9, Room G2-130,1105 AZ, Amsterdam, The Netherlands
| | | | | |
Collapse
|
25
|
Mansur A, von Gruben L, Popov AF, Steinau M, Bergmann I, Ross D, Ghadimi M, Beissbarth T, Bauer M, Hinz J. The regulatory toll-like receptor 4 genetic polymorphism rs11536889 is associated with renal, coagulation and hepatic organ failure in sepsis patients. J Transl Med 2014; 12:177. [PMID: 24950711 PMCID: PMC4085654 DOI: 10.1186/1479-5876-12-177] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 06/18/2014] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Toll-like receptor 4 (TLR4), a lipopolysaccharide (LPS) receptor complex signal-transducing molecule, plays a crucial role in sensing LPS from gram-negative bacteria. TLR4 signaling pathway activation by LPS plays a major role in sepsis pathogenesis. A single nucleotide polymorphism, rs11536889, in the 3'-untranslated region of the TLR4 gene is thought to affect TLR4 translation. This study aimed to investigate whether organ failure in sepsis patients is related to the TLR4 rs11536889 genotype. METHODS Adult Caucasian patients with sepsis from the intensive care unit of a university medical center were followed up for 90 days, and organ failure was recorded as the primary outcome variable. Blood samples were collected at enrollment for TLR4 rs11536889 genotyping. Sepsis-related organ failure assessment (SOFA) scores were quantified at sepsis onset and throughout the observational period to monitor organ failure. RESULTS A total of 210 critically ill patients with sepsis were enrolled into this study. Wild-type GG was compared to GC/CC. During their stay in the intensive care unit, GG patients presented significantly higher SOFA scores than did C allele carriers (7.9 ± 4.5 and 6.8 ± 4.2, respectively; p = 0.0005). Analysis of organ-specific SOFA sub-scores revealed significant differences in three organ systems: renal, coagulation and hepatic (p = 0.0005, p = 0.0245 and p < 0.0001, respectively). Additionally, the rs11536889 polymorphism was associated with a higher incidence of gram-negative infections. CONCLUSIONS These results offer the first evidence that TLR4 rs11536889 is a useful marker of organ failure in patients with sepsis.
Collapse
Affiliation(s)
- Ashham Mansur
- Department of Anesthesiology, University Medical Center, Georg August University, D-37075 Goettingen, Germany.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Wikraiphat C, Pudla M, Baral P, Kitthawee S, Utaisincharoen P. Activation of NADPH oxidase is essential, but not sufficient, in controlling intracellular multiplication of Burkholderia pseudomallei in primary human monocytes. Pathog Dis 2014; 71:69-72. [PMID: 24376210 DOI: 10.1111/2049-632x.12122] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Accepted: 12/15/2013] [Indexed: 12/22/2022] Open
Abstract
Burkholderia pseudomallei is a Gram-negative intracellular bacterium and the causative agent of melioidosis. Innate immune mechanisms against this pathogen, which might contribute to outcomes of melioidosis, are little known. We demonstrated here that B. pseudomallei could activate NADPH oxidase in primary human monocytes as judged by production of reactive oxygen species (ROS) and p40(phox) phosphorylation after infection. However, as similar to other intracellular bacteria, this bacterium was able to resist and multiply inside monocytes despite being able to activate NADPH oxidase. In the presence of NADPH oxidase inhibitor, diphenyleneiodonium or apocynin, intracellular multiplication of B. pseudomallei was significantly increased, suggesting that NADPH oxidase-mediated ROS production is essential in suppressing intracellular multiplication of B. pseudomallei. Additionally, interferon-γ (IFN-γ)-mediated intracellular killing of B. pseudomallei requires NADPH oxidase activity, even though ROS level was not detected at higher levels in IFN-γ-treated infected monocytes. Altogether, these results imply that the activation of NADPH plays an essential role in suppressing intracellular multiplication of B. pseudomallei in human monocytes, although this enzyme is not sufficient to stop intracellular multiplication.
Collapse
Affiliation(s)
- Chanthiwa Wikraiphat
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | | | | | | | | |
Collapse
|
27
|
Glibenclamide reduces pro-inflammatory cytokine production by neutrophils of diabetes patients in response to bacterial infection. Sci Rep 2013; 3:3363. [PMID: 24285369 PMCID: PMC3842541 DOI: 10.1038/srep03363] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 11/12/2013] [Indexed: 12/31/2022] Open
Abstract
Type 2 diabetes mellitus is a major risk factor for melioidosis, which is caused by Burkholderia pseudomallei. Our previous study has shown that polymorphonuclear neutrophils (PMNs) from diabetic subjects exhibited decreased functions in response to B. pseudomallei. Here we investigated the mechanisms regulating cytokine secretion of PMNs from diabetic patients which might contribute to patient susceptibility to bacterial infections. Purified PMNs from diabetic patients who had been treated with glibenclamide (an ATP-sensitive potassium channel blocker for anti-diabetes therapy), showed reduction of interleukin (IL)-1β and IL-8 secretion when exposed to B. pseudomallei. Additionally, reduction of these pro-inflammatory cytokines occurred when PMNs from diabetic patients were treated in vitro with glibenclamide. These findings suggest that glibenclamide might be responsible for the increased susceptibility of diabetic patients, with poor glycemic control, to bacterial infections as a result of its effect on reducing IL-1β production by PMNs.
Collapse
|
28
|
Sterile-α- and armadillo motif-containing protein inhibits the TRIF-dependent downregulation of signal regulatory protein α to interfere with intracellular bacterial elimination in Burkholderia pseudomallei-infected mouse macrophages. Infect Immun 2013; 81:3463-71. [PMID: 23836818 DOI: 10.1128/iai.00519-13] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Burkholderia pseudomallei, the causative agent of melioidosis, evades macrophage killing by suppressing the TRIF-dependent pathway, leading to inhibition of inducible nitric oxide synthase (iNOS) expression. We previously demonstrated that virulent wild-type B. pseudomallei inhibits the TRIF-dependent pathway by upregulating sterile-α- and armadillo motif-containing protein (SARM) and by inhibiting downregulation of signal regulatory protein α (SIRPα); both molecules are negative regulators of Toll-like receptor signaling. In contrast, the less virulent lipopolysaccharide (LPS) mutant of B. pseudomallei is unable to exhibit these features and is susceptible to macrophage killing. However, the functional relationship of these two negative regulators in the evasion of macrophage defense has not been elucidated. We demonstrated here that SIRPα downregulation was observed after inhibition of SARM expression by small interfering RNA in wild-type-infected macrophages, indicating that SIRPα downregulation is regulated by SARM. Furthermore, this downregulation requires activation of the TRIF signaling pathway, as we observed abrogation of SIRPα downregulation as well as restricted bacterial growth in LPS mutant-infected TRIF-depleted macrophages. Although inhibition of SARM expression is correlated to SIRPα downregulation and iNOS upregulation in gamma interferon-activated wild-type-infected macrophages, these phenomena appear to bypass the TRIF-dependent pathway. Similar to live bacteria, the wild-type LPS is able to upregulate SARM and to prevent SIRPα downregulation, implying that the LPS of B. pseudomallei may play a crucial role in regulating the expression of these two negative regulators. Altogether, our findings show a previously unrecognized role of B. pseudomallei-induced SARM in inhibiting SIRPα downregulation-mediated iNOS upregulation, facilitating the ability of the bacterium to multiply in macrophages.
Collapse
|
29
|
Deng M, Scott MJ, Loughran P, Gibson G, Sodhi C, Watkins S, Hackam D, Billiar TR. Lipopolysaccharide clearance, bacterial clearance, and systemic inflammatory responses are regulated by cell type-specific functions of TLR4 during sepsis. THE JOURNAL OF IMMUNOLOGY 2013; 190:5152-60. [PMID: 23562812 DOI: 10.4049/jimmunol.1300496] [Citation(s) in RCA: 144] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The morbidity associated with bacterial sepsis is the result of host immune responses to pathogens, which are dependent on pathogen recognition by pattern recognition receptors, such as TLR4. TLR4 is expressed on a range of cell types, yet the mechanisms by which cell-specific functions of TLR4 lead to an integrated sepsis response are poorly understood. To address this, we generated mice in which TLR4 was specifically deleted from myeloid cells (LysMTLR4KO) or hepatocytes (HCTLR4KO) and then determined survival, bacterial counts, host inflammatory responses, and organ injury in a model of cecal ligation and puncture (CLP), with or without antibiotics. LysM-TLR4 was required for phagocytosis and efficient bacterial clearance in the absence of antibiotics. Survival, the magnitude of the systemic and local inflammatory responses, and liver damage were associated with bacterial levels. HCTLR4 was required for efficient LPS clearance from the circulation, and deletion of HCTLR4 was associated with enhanced macrophage phagocytosis, lower bacterial levels, and improved survival in CLP without antibiotics. Antibiotic administration during CLP revealed an important role for hepatocyte LPS clearance in limiting sepsis-induced inflammation and organ injury. Our work defines cell type-selective roles for TLR4 in coordinating complex immune responses to bacterial sepsis and suggests that future strategies for modulating microbial molecule recognition should account for varying roles of pattern recognition receptors in multiple cell populations.
Collapse
Affiliation(s)
- Meihong Deng
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Silva EB, Dow SW. Development of Burkholderia mallei and pseudomallei vaccines. Front Cell Infect Microbiol 2013; 3:10. [PMID: 23508691 PMCID: PMC3598006 DOI: 10.3389/fcimb.2013.00010] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 02/20/2013] [Indexed: 12/16/2022] Open
Abstract
Burkholderia mallei and Burkholderia pseudomallei are Gram-negative bacteria that cause glanders and melioidosis, respectively. Inhalational infection with either organism can result in severe and rapidly fatal pneumonia. Inoculation by the oral and cutaneous routes can also produce infection. Chronic infection may develop after recovery from acute infection with both agents, and control of infection with antibiotics requires prolonged treatment. Symptoms for both meliodosis and glanders are non-specific, making diagnosis difficult. B. pseudomallei can be located in the environment, but in the host, B. mallei and B. psedomallei are intracellular organisms, and infection results in similar immune responses to both agents. Effective early innate immune responses are critical to controlling the early phase of the infection. Innate immune signaling molecules such as TLR, NOD, MyD88, and pro-inflammatory cytokines such as IFN-γ and TNF-α play key roles in regulating control of infection. Neutrophils and monocytes are critical cells in the early infection for both microorganisms. Both monocytes and macrophages are necessary for limiting dissemination of B. pseudomallei. In contrast, the role of adaptive immune responses in controlling Burkholderia infection is less well understood. However, T cell responses are critical for vaccine protection from Burkholderia infection. At present, effective vaccines for prevention of glanders or meliodosis have not been developed, although recently development of Burkholderia vaccines has received renewed attention. This review will summarize current and past approaches to develop B. mallei and B. pseudomalllei vaccines, with emphasis on immune mechanisms of protection and the challenges facing the field. At present, immunization with live attenuated bacteria provides the most effective and durable immunity, and it is important therefore to understand the immune correlates of protection induced by live attenuated vaccines. Subunit vaccines have typically provided less robust immunity, but are safer to administer to a wider variety of people, including immune compromised individuals because they do not reactivate or cause disease. The challenges facing B. mallei and B. pseudomalllei vaccine development include identification of broadly protective antigens, design of efficient vaccine delivery and adjuvant systems, and a better understanding of the correlates of protection from both acute and chronic infection.
Collapse
Affiliation(s)
- Ediane B Silva
- Department of Microbiology, Immunology, and Pathology, Regional Center of Excellence in Emerging Diseases and Bioterrorism, Colorado State University Ft. Collins, CO, USA
| | | |
Collapse
|
31
|
von Bernuth H, Picard C, Puel A, Casanova JL. Experimental and natural infections in MyD88- and IRAK-4-deficient mice and humans. Eur J Immunol 2013; 42:3126-35. [PMID: 23255009 PMCID: PMC3752658 DOI: 10.1002/eji.201242683] [Citation(s) in RCA: 131] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 08/11/2012] [Accepted: 10/25/2012] [Indexed: 01/15/2023]
Abstract
Most Toll-like-receptors (TLRs) and interleukin-1 receptors (IL-1Rs) signal via myeloid differentiation primary response 88 (MyD88) and interleukin-1 receptor-associated kinase 4 (IRAK-4). The combined roles of these two receptor families in the course of experimental infections have been assessed in MyD88- and IRAK-4-deficient mice for almost fifteen years. These animals have been shown to be susceptible to 46 pathogens: 27 bacteria, eight viruses, seven parasites, and four fungi. Humans with inborn MyD88 or IRAK-4 deficiency were first identified in 2003. They suffer from naturally occurring life-threatening infections caused by a small number of bacterial species, although the incidence and severity of these infections decrease with age. Mouse TLR- and IL-1R-dependent immunity mediated by MyD88 and IRAK-4 seems to be vital to combat a wide array of experimentally administered pathogens at most ages. By contrast, human TLR- and IL-1R-dependent immunity mediated by MyD88 and IRAK-4 seems to be effective in the natural setting against only a few bacteria and is most important in infancy and early childhood. The roles of TLRs and IL-1Rs in protective immunity deduced from studies in mutant mice subjected to experimental infections should therefore be reconsidered in the light of findings for natural infections in humans carrying mutations as discussed in this review.
Collapse
Affiliation(s)
- Horst von Bernuth
- Pediatric Pneumology and Immunology, Charité Hospital - Humboldt University, Berlin, Germany.
| | | | | | | |
Collapse
|
32
|
Tan ZY, Khah AKL, Sim SH, Novem V, Liu Y, Tan GYG. Synthetic TLR4 agonist as a potential immunotherapy for melioidosis. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/oji.2013.31001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
33
|
Lu R, Popov V, Patel J, Eaves-Pyles T. Burkholderia mallei and Burkholderia pseudomallei stimulate differential inflammatory responses from human alveolar type II cells (ATII) and macrophages. Front Cell Infect Microbiol 2012; 2:165. [PMID: 23293773 PMCID: PMC3531596 DOI: 10.3389/fcimb.2012.00165] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 12/07/2012] [Indexed: 01/11/2023] Open
Abstract
Alveolar type II pneumocytes (ATII) and alveolar macrophages (AM) play a crucial role in the lung's innate immune response. Burkholderia pseudomallei (BP) and Burkholderia mallei (BM) are facultative Gram-negative bacilli that cause melioidosis and glanders, respectively. The inhalation of these pathogens can cause lethal disease and death in humans. We sought to compare the pathogenesis of and host responses to BP and BM through contact with human primary ATII cells and monocytes-derived macrophages (MDM). We hypothesized that because BP and BM induce different disease outcomes, each pathogen would induce distinct, unique host immune responses from resident pulmonary cells. Our findings showed that BP adhered readily to ATII cells compared to BM. BP, but not BM, was rapidly internalized by macrophages where it replicated to high numbers. Further, BP-induced significantly higher levels of pro-inflammatory cytokine secretion from ATII cells (IL-6, IL-8) and macrophages (IL-6, TNFα) at 6 h post-infection compared to BM (p < 0.05). Interestingly, BM-induced the anti-inflammatory cytokine, IL-10, in ATII cells and macrophages at 6 h post-infection, with delayed induction of inflammatory cytokines at 24 h post-infection. Because BP is flagellated and produces LPS, we confirmed that it stimulated both Toll-like receptor (TLR) 4 and TLR5 via NF-κb activation while the non-flagellated BM stimulated only TLR4. These data show the differences in BP and BM pathogenicity in the lung when infecting human ATII cells and macrophages and demonstrate the ability of these pathogens to elicit distinct immune responses from resident lung cells which may open new targets for therapeutic intervention to fight against these pathogens.
Collapse
Affiliation(s)
- Richard Lu
- Department of Microbiology and Immunology, University of Texas Medical Branch Galveston, TX, USA
| | | | | | | |
Collapse
|
34
|
Achouiti A, Vogl T, Urban CF, Röhm M, Hommes TJ, van Zoelen MAD, Florquin S, Roth J, van 't Veer C, de Vos AF, van der Poll T. Myeloid-related protein-14 contributes to protective immunity in gram-negative pneumonia derived sepsis. PLoS Pathog 2012; 8:e1002987. [PMID: 23133376 PMCID: PMC3486918 DOI: 10.1371/journal.ppat.1002987] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 09/09/2012] [Indexed: 12/30/2022] Open
Abstract
Klebsiella (K.) pneumoniae is a common cause of pneumonia-derived sepsis. Myeloid related protein 8 (MRP8, S100A8) and MRP14 (S100A9) are the most abundant cytoplasmic proteins in neutrophils. They can form MRP8/14 heterodimers that are released upon cell stress stimuli. MRP8/14 reportedly exerts antimicrobial activity, but in acute fulminant sepsis models MRP8/14 has been found to contribute to organ damage and death. We here determined the role of MRP8/14 in K. pneumoniae sepsis originating from the lungs, using an established model characterized by gradual growth of bacteria with subsequent dissemination. Infection resulted in gradually increasing MRP8/14 levels in lungs and plasma. Mrp14 deficient (mrp14−/−) mice, unable to form MRP8/14 heterodimers, showed enhanced bacterial dissemination accompanied by increased organ damage and a reduced survival. Mrp14−/− macrophages were reduced in their capacity to phagocytose Klebsiella. In addition, recombinant MRP8/14 heterodimers, but not MRP8 or MRP14 alone, prevented growth of Klebsiella in vitro through chelation of divalent cations. Neutrophil extracellular traps (NETs) prepared from wildtype but not from mrp14−/− neutrophils inhibited Klebsiella growth; in accordance, the capacity of human NETs to kill Klebsiella was strongly impaired by an anti-MRP14 antibody or the addition of zinc. These results identify MRP8/14 as key player in protective innate immunity during Klebsiella pneumonia. Neutrophils are phagocytes that are well known for their capacity to engulf and kill microbial pathogens. It has become increasingly clear that neutrophils also kill or inhibit growth extracellularly by releasing neutrophil extracellular traps (NETs), chromatin fibers decorated with neutrophil derived proteins. MRP8/14 has been identified as one of the major antimicrobial proteins herein. Previous investigations have shown that endogenously released MRP8/14 is also sensed by the host as a danger signal and able to potentiate the harmful systemic inflammatory response syndrome. Indeed, in the setting of fulminant systemic inflammation, such as induced by endotoxin or Escherichia coli administration, MRP8/14 contributed to organ injury and mortality. The clinical scenario of sepsis however, involves an initial infection at the primary site followed by bacterial spreading to other organs. In the present setting of pneumonia-derived sepsis using the common human respiratory and sepsis pathogen Klebsiella pneumoniae MRP8/14 clearly served a beneficial role in antimicrobial defense. We here provide a likely mechanism by showing that MRP8/14 plays a role in phagocytosis and that its presence is critical in both murine and human NETs to inhibit bacterial growth.
Collapse
Affiliation(s)
- Ahmed Achouiti
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Ooi SK, Lim TY, Lee SH, Nathan S. Burkholderia pseudomallei kills Caenorhabditis elegans through virulence mechanisms distinct from intestinal lumen colonization. Virulence 2012; 3:485-96. [PMID: 23076282 PMCID: PMC3524147 DOI: 10.4161/viru.21808] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The nematode Caenorhabditis elegans is hypersusceptible to Burkholderia pseudomallei infection. However, the virulence mechanisms underlying rapid lethality of C. elegans upon B. pseudomallei infection remain poorly defined. To probe the host-pathogen interaction, we constructed GFP-tagged B. pseudomallei and followed bacterial accumulation within the C. elegans intestinal lumen. Contrary to slow-killing by most bacterial pathogens, B. pseudomallei caused fairly limited intestinal lumen colonization throughout the period of observation. Using grinder-defective mutant worms that allow the entry of intact bacteria also did not result in full intestinal lumen colonization. In addition, we observed a significant decline in C. elegans defecation and pharyngeal pumping rates upon B. pseudomallei infection. The decline in defecation rates ruled out the contribution of defecation to the limited B. pseudomallei colonization. We also demonstrated that the limited intestinal lumen colonization was not attributed to slowed host feeding as bacterial loads did not change significantly when feeding was stimulated by exogenous serotonin. Both these observations confirm that B. pseudomallei is a poor colonizer of the C. elegans intestine. To explore the possibility of toxin-mediated killing, we examined the transcription of the C. elegans ABC transporter gene, pgp-5, upon B. pseudomallei infection of the ppgp-5::gfp reporter strain. Expression of pgp-5 was highly induced, notably in the pharynx and intestine, compared with Escherichia coli-fed worms, suggesting that the host actively thwarted the pathogenic assaults during infection. Collectively, our findings propose that B. pseudomallei specifically and continuously secretes toxins to overcome C. elegans immune responses.
Collapse
Affiliation(s)
- Soon-Keat Ooi
- School of Biosciences and Biotechnology; Faculty of Science and Technology; Universiti Kebangsaan Malaysia; Bangi, Selangor, Malaysia
| | - Tian-Yeh Lim
- School of Biosciences and Biotechnology; Faculty of Science and Technology; Universiti Kebangsaan Malaysia; Bangi, Selangor, Malaysia
| | - Song-Hua Lee
- School of Biosciences and Biotechnology; Faculty of Science and Technology; Universiti Kebangsaan Malaysia; Bangi, Selangor, Malaysia
| | - Sheila Nathan
- School of Biosciences and Biotechnology; Faculty of Science and Technology; Universiti Kebangsaan Malaysia; Bangi, Selangor, Malaysia
- Malaysia Genome Institute; Kajang, Selangor, Malaysia
| |
Collapse
|
36
|
Hoogerwerf JJ, van der Windt GJW, Blok DC, Hoogendijk AJ, De Vos AF, van 't Veer C, Florquin S, Kobayashi KS, Flavell RA, van der Poll T. Interleukin-1 receptor-associated kinase M-deficient mice demonstrate an improved host defense during Gram-negative pneumonia. Mol Med 2012; 18:1067-75. [PMID: 22729155 DOI: 10.2119/molmed.2011.00450] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2011] [Accepted: 06/18/2012] [Indexed: 11/06/2022] Open
Abstract
Pneumonia is a common cause of morbidity and mortality and the most frequent source of sepsis. Bacteria that try to invade normally sterile body sites are recognized by innate immune cells through pattern recognition receptors, among which toll-like receptors (TLRs) feature prominently. Interleukin-1 receptor (IL-1R)-associated kinase (IRAK)-M is a proximal inhibitor of TLR signaling expressed by epithelial cells and macrophages in the lung. To determine the role of IRAK-M in host defense against bacterial pneumonia, IRAK-M-deficient (IRAK-M(-/-)) and normal wild-type (WT) mice were infected intranasally with Klebsiella pneumoniae. IRAK-M mRNA was upregulated in lungs of WT mice with Klebsiella pneumonia, and the absence of IRAK-M resulted in a strongly improved host defense as reflected by reduced bacterial growth in the lungs, diminished dissemination to distant body sites, less peripheral tissue injury and better survival rates. Although IRAK-M(-/-) alveolar macrophages displayed enhanced responsiveness toward intact K. pneumoniae and Klebsiella lipopolysaccharide (LPS) in vitro, IRAK-M(-/-) mice did not show increased cytokine or chemokine levels in their lungs after infection in vivo. The extent of lung inflammation was increased in IRAK-M(-/-) mice shortly after K. pneumoniae infection, as determined by semiquantitative scoring of specific components of the inflammatory response in lung tissue slides. These data indicate that IRAK-M impairs host defense during pneumonia caused by a common gram-negative respiratory pathogen.
Collapse
Affiliation(s)
- Jacobien J Hoogerwerf
- Center for Infection and Immunity Amsterdam, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Involvement of signal regulatory protein α, a negative regulator of Toll-like receptor signaling, in impairing the MyD88-independent pathway and intracellular killing of Burkholderia pseudomallei-infected mouse macrophages. Infect Immun 2012; 80:4223-31. [PMID: 22988019 DOI: 10.1128/iai.00718-12] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The facultative intracellular gram-negative bacterium Burkholderia pseudomallei is the causative agent of melioidosis and is known for its ability to evade the Toll-like receptor (TLR)-mediated innate immune response. Previously it has been demonstrated that this bacterium was able to suppress the MyD88-independent pathway and can survive macrophage intracellular killing. However, the underlying mechanisms responsible for the suppression of this pathway are not fully understood. In the present study, we showed that both living and heat-killed B. pseudomallei bacteria restrict the TLR signaling response, particularly macrophage inducible nitric oxide synthase (iNOS) expression, by preventing downregulation of constitutively expressed signal regulatory protein α (SIRPα) molecule, a known negative regulator of TLR signaling. In contrast, a lipopolysaccharide (LPS) mutant of B. pseudomallei, a less virulent strain, was able to downregulate SIRPα expression in mouse macrophages. However, depletion of constitutively expressed SIRPα was able to induce the gene expression downstream of TLR signaling pathways (particularly the MyD88-independent pathway), such as that of the iNOS gene, leading to enhanced macrophage intracellular killing of B. pseudomallei. Induction of gene expression was consistent with the enhanced degradation pattern of IκBα with SIRPα depletion. Additionally, the downregulation of SIRPα expression with upregulation of iNOS was observed when the macrophages were pretreated with gamma interferon (IFN-γ) prior to the infection, suggesting that the enhanced intracellular killing of bacteria by IFN-γ is associated with the decreased SIRPα expression. Altogether our findings demonstrate that B. pseudomallei evades macrophage intracellular killing by preventing the downregulation of SIRPα that results in the inhibition of gene expression downstream of the MyD88-independent pathway.
Collapse
|
38
|
Sotolongo J, Kanagavelu S, Hyun J, Ruiz J, Fukata M. TRIF mobilizes unique primary defense against Gram-negative bacteria in intestinal interface. Gut Microbes 2012; 3:437-41. [PMID: 22713267 PMCID: PMC3679230 DOI: 10.4161/gmic.20873] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The gastrointestinal tract is the largest mucosal surface in our body. It houses diverse microorganisms that collectively form the commensal microbial community. The security of this community is kept by host-microbial interactions and is violated by foreign pathogens that induce local as well as systemic pathology. In most cases, gastrointestinal infections are caused by Gram-negative enteropathogens, which trigger host immune responses through the TLR4 signaling pathways. Although TRIF is one of the major pathways downstream of TLR4, very little is known about how the TRIF pathway contributes to intestinal defense against pathogenic infection. Recently, we reported a unique role of TRIF signaling in host response to an enterophathogen Yersinia enterocolitica, which consisted of IFN-β induction from regional macrophages followed by activation of NK cells in the mesenteric lymph nodes. In this addendum, we show distinct roles for TRIF-dependent host response in intestinal vs. systemic infection with Gram-negative enterophathogens.
Collapse
|
39
|
Cationic liposomes extend the immunostimulatory effect of CpG oligodeoxynucleotide against Burkholderia pseudomallei infection in BALB/c mice. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 19:675-83. [PMID: 22441390 DOI: 10.1128/cvi.05545-11] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Melioidosis is a severe disease caused by the Gram-negative bacterium Burkholderia pseudomallei. Previously we showed that pretreatment of mice with CpG oligodeoxynucleotide (CpG ODN) 2 to 10 days prior to B. pseudomallei challenge conferred as high as 90% protection, but this window of protection was rather short. In the present study, we therefore aimed to prolong this protective window and to gain further insight into the mechanisms underlying the protection induced by CpG ODN against B. pseudomallei infection. It was found that the CpG ODN incorporated with cationic liposomes (DOTAP) but not zwitterionic liposomes (DOPC) provided complete protection against bacterial challenge. Although marked elevation of gamma interferon (IFN-γ) was found in the infected animals 2 days postinfection, it was significantly lowered by the DOTAP-plus-CpG ODN pretreatment. When appropriately activated, the phagocytic index and oxidative burst responses of neutrophils appeared not to be elevated. However, macrophages from stimulated mice showed higher levels of nitric oxide production and exhibited higher levels of antimicrobial activities, judging from lower numbers of viable intracellular bacteria. Taken together, our results demonstrate that DOTAP can enhance the protective window period of CpG ODN to at least 30 days and provide 100% protection against B. pseudomallei infection. The protective effect of DOTAP plus CpG ODN could provide an alternative approach to preventing this lethal infection, for which no vaccine is yet available.
Collapse
|
40
|
Abstract
Melioidosis, caused by the Gram-negative bacterium Burkholderia pseudomallei, is an important cause of community-acquired sepsis in Southeast Asia and northern Australia. An important controller of the immune system is the pleiotropic cytokine transforming growth factor β (TGF-β), of which Smad2 and Smad3 are the major signal transducers. In this study, we aimed to characterize TGF-β expression and function in experimental melioidosis. TGF-β expression was determined in 33 patients with culture-proven infection with B. pseudomallei and 30 healthy controls. We found that plasma TGF-β concentrations were strongly elevated during melioidosis. In line with this finding, TGF-β expression in C57BL/6 mice intranasally inoculated with B. pseudomallei was enhanced as well. To assess the role of TGF-β, we inhibited TGF-β using a selective murine TGF-β antibody. Treatment of mice with anti-TGF-β antibody resulted in decreased lung Smad2 phosphorylation. TGF-β blockade appeared to be protective: mice treated with anti-TGF-β antibody and subsequently infected with B. pseudomallei showed diminished bacterial loads. Moreover, less distant organ injury was observed in anti-TGF-β treated mice as shown by reduced blood urea nitrogen (BUN) and aspartate transaminase (AST) values. However, anti-TGF-β treatment did not have an effect on survival. In conclusion, TGF-β is upregulated during B. pseudomallei infection and plays a limited but proinflammatory role during experimental melioidosis.
Collapse
|
41
|
Luo HL, Wang DY, Wang HJ, Nie K, Huang WY. WITHDRAWN: MyD88 is required for the recruitment of eosinophils and neutrophils but dispensable for host protective immune responses during Fasciola hepatica infection. Immunobiology 2011:S0171-2985(11)00265-8. [PMID: 22226670 DOI: 10.1016/j.imbio.2011.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2011] [Revised: 12/07/2011] [Accepted: 12/11/2011] [Indexed: 11/15/2022]
Abstract
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
Collapse
Affiliation(s)
- H L Luo
- Lab of Infection & Immunology Research, College of Animal Science & Technology, Southwest University,Chongqing,China
| | | | | | | | | |
Collapse
|
42
|
MyD88-dependent recruitment of monocytes and dendritic cells required for protection from pulmonary Burkholderia mallei infection. Infect Immun 2011; 80:110-20. [PMID: 22025508 DOI: 10.1128/iai.05819-11] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The Gram-negative bacterium Burkholderia mallei causes rapidly fatal illness in equines and humans when contracted by inhalation and also has the potential to be used as a bioweapon. However, little is known regarding the early innate immune responses and signaling mechanisms required to generate protection from pneumonic B. mallei infection. We showed previously that monocyte chemoattractant protein 1 (MCP-1) was a critical chemokine required for protection from pneumonic B. mallei infection. We have now extended those studies to identify key Toll-like receptor (TLR) signaling pathways, effector cells, and cytokines required for protection from respiratory B. mallei infection. We found that MyD88-/- mice were highly susceptible to pulmonary challenge with B. mallei and had significantly short survival times, increased bacterial burdens, and severe organ pathology compared to wild-type mice. Notably, MyD88-/- mice had significantly fewer monocytes and dendritic cells (DCs) in lung tissues and airways than infected wild-type mice despite markedly higher bacterial burdens. The MyD88-/- mice were also completely unable to produce gamma interferon (IFN-γ) at any time points following infection. In wild-type mice, NK cells were the primary cells producing IFN-γ in the lungs following B. mallei infection, while DCs and monocytes were the primary cellular sources of interleukin-12 (IL-12) production. Treatment with recombinant IFN-γ (rIFN-γ) was able to significantly restore protective immunity in MyD88-/- mice. Thus, we conclude that the MyD88-dependent recruitment of inflammatory monocytes and DCs to the lungs and the local production of IL-12, followed by NK cell production of IFN-γ, are the key initial cellular responses required for early protection from B. mallei infection.
Collapse
|
43
|
Patel N, Conejero L, De Reynal M, Easton A, Bancroft GJ, Titball RW. Development of vaccines against burkholderia pseudomallei. Front Microbiol 2011; 2:198. [PMID: 21991263 PMCID: PMC3180847 DOI: 10.3389/fmicb.2011.00198] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Accepted: 09/06/2011] [Indexed: 12/20/2022] Open
Abstract
Burkholderia pseudomallei is a Gram-negative bacterium which is the causative agent of melioidosis, a disease which carries a high mortality and morbidity rate in endemic areas of South East Asia and Northern Australia. At present there is no available human vaccine that protects against B. pseudomallei, and with the current limitations of antibiotic treatment, the development of new preventative and therapeutic interventions is crucial. This review considers the multiple elements of melioidosis vaccine research including: (i) the immune responses required for protective immunity, (ii) animal models available for preclinical testing of potential candidates, (iii) the different experimental vaccine strategies which are being pursued, and (iv) the obstacles and opportunities for eventual registration of a licensed vaccine in humans.
Collapse
Affiliation(s)
- Natasha Patel
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine London, UK
| | | | | | | | | | | |
Collapse
|
44
|
van 't Veer C, van den Pangaart PS, Kruijswijk D, Florquin S, de Vos AF, van der Poll T. Delineation of the role of Toll-like receptor signaling during peritonitis by a gradually growing pathogenic Escherichia coli. J Biol Chem 2011; 286:36603-18. [PMID: 21690093 DOI: 10.1074/jbc.m110.189126] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
In a mouse model of Escherichia coli sepsis characterized by a primary peritoneal infection with 10(4) E. coli and a gradually growing bacterial load, we here show that the early cytokine response and antibacterial defense are dominated by TLR4 via a cooperative action of MyD88 and Trif. Although MyD88(-/-) mice succumbed earlier than WT mice in this E. coli peritonitis model, Trif(-/-) mice displayed a small but significant survival advantage. Despite a large early deficit in antimicrobial defense, TLR4(-/-) mice showed an unaltered survival with normal neutrophil attraction to the peritoneal cavity and normal or even elevated late cytokine release. TLR2 compensated for the lack of TLR4 because TLR2(-/-)/TLR4(-/-) mice did show decreased neutrophil attraction and increased mortality compared with WT mice. Nearly normal early peritoneal TNFα production and lack of early counterregulating systemic levels of the chemoattractant KC were associated with normal peritoneal neutrophil attraction in TLR4(-/-) mice. Late stage increased TNF, IL-1β, IFN-β, and typical IFN-γ production in TLR4(-/-) mice prompted us to evaluate expression of the negative feedback regulator SOCS-1. Lack of early hepatic SOCS-1 expression in TLR4(-/-) mice explained the late innate production of IFN-γ by the liver in TLR4(-/-) mice in this low dose E. coli peritonitis model. In contrast, early TLR4-induced IFN-γ production is described as a hallmark in high dose E. coli peritonitis models. The present study displays how the kinetics of pro- and anti-inflammatory mechanisms are regulated by TLRs during peritonitis by a gradually growing E. coli load and how these kinetics may affect outcome.
Collapse
Affiliation(s)
- Cornelis van 't Veer
- Center for Infection and Immunity Amsterdam, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands.
| | | | | | | | | | | |
Collapse
|
45
|
van der Windt GJW, Hoogendijk AJ, Schouten M, Hommes TJ, de Vos AF, Florquin S, van der Poll T. Osteopontin Impairs Host Defense During Pneumococcal Pneumonia. J Infect Dis 2011; 203:1850-8. [DOI: 10.1093/infdis/jir185] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
|
46
|
Conejero L, Patel N, de Reynal M, Oberdorf S, Prior J, Felgner PL, Titball RW, Salguero FJ, Bancroft GJ. Low-dose exposure of C57BL/6 mice to burkholderia pseudomallei mimics chronic human melioidosis. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:270-80. [PMID: 21703409 DOI: 10.1016/j.ajpath.2011.03.031] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Revised: 03/23/2011] [Accepted: 03/29/2011] [Indexed: 12/15/2022]
Abstract
Burkholderia pseudomallei is the etiological agent of human melioidosis, a disease with a broad spectrum of clinical manifestations ranging from fatal septicemia to chronic localized infection or asymptomatic latent infection. Most clinical and immunological studies to date have focused on the acute disease process; however, little is known about pathology and immune response in chronic melioidosis. Here, we have developed a murine model of chronic disease by challenging C57BL/6 mice intranasally with a low dose of B. pseudomallei and monitoring them up to 100 days postinfection. Bacterial burdens were heterogeneous in different animals at all time points, consistent with the spectrum of clinical severity observed in humans. Proinflammatory cytokines such as gamma interferon (IFN-γ), interleukin-6 (IL-6), monocyte chemotactic protein-1 (MCP-1), and tumor necrosis factor-α (TNF-α) were induced during chronic infection, and histopathological analysis showed features in common with human melioidosis. Interestingly, many of these features were similar to those induced by Mycobacterium tuberculosis in humans, such as development of a collagen cord that encapsulates the lesions, the presence of multinucleated giant cells, and granulomas with a caseous necrotic center, which may explain why chronic melioidosis is often misdiagnosed as tuberculosis. Our model now provides a relevant and practical tool to define the immunological features of chronic melioidosis and aid in the development of more effective treatment of this disease in humans.
Collapse
Affiliation(s)
- Laura Conejero
- Department of Immunology and Infection, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
MyD88 signaling is required for efficient innate and adaptive immune responses to Paracoccidioides brasiliensis infection. Infect Immun 2011; 79:2470-80. [PMID: 21422180 DOI: 10.1128/iai.00375-10] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The mechanisms that govern the initial interaction between Paracoccidioides brasiliensis, a primary dimorphic fungal pathogen, and cells of the innate immunity need to be clarified. Our previous studies showed that Toll-like receptor 2 (TLR2) and TLR4 regulate the initial interaction of fungal cells with macrophages and the pattern of adaptive immunity that further develops. The aim of the present investigation was to assess the role of MyD88, an adaptor molecule used by TLRs to activate genes of the inflammatory response in pulmonary paracoccidioidomycosis. Studies were performed with normal and MyD88(-/-) C57BL/6 mice intratracheally infected with P. brasiliensis yeast cells. MyD88(-/-) macrophages displayed impaired interaction with fungal yeast cells and produced low levels of IL-12, MCP-1, and nitric oxide, thus allowing increased fungal growth. Compared with wild-type (WT) mice, MyD88(-/-) mice developed a more severe infection of the lungs and had marked dissemination of fungal cells to the liver and spleen. MyD88(-/-) mice presented low levels of Th1, Th2, and Th17 cytokines, suppressed lymphoproliferation, and impaired influx of inflammatory cells to the lungs, and this group of cells comprised lower numbers of neutrophils, activated macrophages, and T cells. Nonorganized, coalescent granulomas, which contained high numbers of fungal cells, characterized the severe lesions of MyD88(-/-) mice; the lesions replaced extensive areas of several organs. Therefore, MyD88(-/-) mice were unable to control fungal growth and showed a significantly decreased survival time. In conclusion, our findings demonstrate that MyD88 signaling is important in the activation of fungicidal mechanisms and the induction of protective innate and adaptive immune responses against P. brasiliensis.
Collapse
|
48
|
Liu D, Yao S, Wise GE. MyD88 expression in the rat dental follicle: implications for osteoclastogenesis and tooth eruption. Eur J Oral Sci 2010; 118:333-41. [PMID: 20662905 DOI: 10.1111/j.1600-0722.2010.00751.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Myeloid differentiation factor 88 (MyD88) is a key adaptor molecule in the interleukin (IL)-1 and IL-18 toll-like receptor signaling pathways. Because MyD88 is present in dental follicle (DF) cells in vitro, the purpose of this study was to determine its chronological expression in vivo, as well as its possible role in osteoclastogenesis and tooth eruption. An oligo DNA microarray was used to determine expression of the Myd88 gene in vivo in the DFs from the first mandibular molars of postnatal rats from days 1 to 11. The results showed that MyD88 was expressed maximally on day 3. Using small interfering RNA (siRNA) to knock down MyD88 expression in the DF cells also reduced the expression of the nuclear factor-kappa B-1 (NFKB1) and monocyte chemoattractant protein 1 (MCP-1) genes. Interleukin-1alpha up-regulated the expression of NFKB1, MCP-1, and receptor activator of nuclear factor kappa B ligand (RANKL), but knockdown of MyD88 nullified this IL-1alpha effect. Conditioned medium from DF cells with MyD88 knocked down had reduced chemotactic activity for mononuclear cells and reduced osteoclastogenesis, as opposed to controls. In conclusion, the maximal expression of MyD88 in the DF of postnatal day 3 rats may contribute to the major burst of osteoclastogenesis needed for eruption by up-regulating MCP-1 and RANKL expression.
Collapse
Affiliation(s)
- Dawen Liu
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA
| | | | | |
Collapse
|
49
|
MyD88 signaling is indispensable for primary influenza A virus infection but dispensable for secondary infection. J Virol 2010; 84:12713-22. [PMID: 20943980 DOI: 10.1128/jvi.01675-10] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Recent studies have revealed that innate immunity is involved in the development of adaptive immune responses; however, its role in protection is not clear. In order to elucidate the exact role of Toll-like receptor (TLR) or RIG-I-like receptor (RLR) signaling on immunogenicity and protective efficacy against influenza A virus infection (A/PR/8/34 [PR8]; H1N1), we adapted several innate signal-deficient mice (e.g., TRIF(-/-), MyD88(-/-), MyD88(-/-) TRIF(-/-), TLR3(-/-) TLR7(-/-), and IPS-1(-/-)). In this study, we found that MyD88 signaling was required for recruitment of CD11b(+) granulocytes, production of early inflammatory cytokines, optimal proliferation of CD4 T cells, and production of Th1 cytokines by T cells. However, PR8 virus-specific IgG and IgA antibody levels in both systemic and mucosal compartments were normal in TLR- and RLR-deficient mice. To further assess the susceptibility of these mice to influenza virus infection, protective efficacy was determined after primary or secondary lethal challenge. We found that MyD88(-/-) and MyD88(-/-) TRIF(-/-) mice were more susceptible to primary influenza virus infection than the B6 mice but were fully protected against homologous (H1N1) and heterosubtypic (H5N2) secondary infection when primed with a nonlethal dose of PR8 virus. Taken together, these results show that MyD88 signaling plays an important role for resisting primary influenza virus infection but is dispensable for protection against a secondary lethal challenge.
Collapse
|
50
|
van der Windt GJW, Wiersinga WJ, Wieland CW, Tjia ICSI, Day NP, Peacock SJ, Florquin S, van der Poll T. Osteopontin impairs host defense during established gram-negative sepsis caused by Burkholderia pseudomallei (melioidosis). PLoS Negl Trop Dis 2010; 4. [PMID: 20824216 PMCID: PMC2930856 DOI: 10.1371/journal.pntd.0000806] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Accepted: 07/30/2010] [Indexed: 11/18/2022] Open
Abstract
Background Melioidosis, caused by infection with Burkholderia (B.) pseudomallei, is a severe illness that is endemic in Southeast Asia. Osteopontin (OPN) is a phosphorylated glycoprotein that is involved in several immune responses including induction of T-helper 1 cytokines and recruitment of inflammatory cells. Methodology and Principal Findings OPN levels were determined in plasma from 33 melioidosis patients and 31 healthy controls, and in wild-type (WT) mice intranasally infected with B. pseudomallei. OPN function was studied in experimental murine melioidosis using WT and OPN knockout (KO) mice. Plasma OPN levels were elevated in patients with severe melioidosis, even more so in patients who went on to die. In patients who recovered plasma OPN concentrations had decreased after treatment. In experimental melioidosis in mice plasma and pulmonary OPN levels were also increased. Whereas WT and OPN KO mice were indistinguishable during the first 24 hours after infection, after 72 hours OPN KO mice demonstrated reduced bacterial numbers in their lungs, diminished pulmonary tissue injury, especially due to less necrosis, and decreased neutrophil infiltration. Moreover, OPN KO mice displayed a delayed mortality as compared to WT mice. OPN deficiency did not influence the induction of proinflammatory cytokines. Conclusions These data suggest that sustained production of OPN impairs host defense during established septic melioidosis. Melioidosis is a severe tropical disease caused by infection with the bacterium Burkholderia (B.) pseudomallei. In northeast Thailand infection with this bacterium is the major cause of community-acquired septicemia with a mortality rate up to 40%. Extending the knowledge on the mechanisms of host defense against B. pseudomallei infection would be helpful to improve treatment of this severe illness. Osteopontin (OPN) is a cytokine that is involved in several immune responses that occur during bacterial infection. In this study, we investigated levels of OPN in patients with melioidosis, and studied the function of OPN during experimental melioidosis in mice. We found that OPN concentrations were elevated in patients with severe melioidosis, and that high OPN concentrations are associated with poor outcome in patients with melioidosis. In experimental melioidosis in mice plasma and lung OPN levels were also increased. Moreover, mice with melioidosis that were deficient for OPN demonstrated reduced bacterial numbers in their lungs, diminished pulmonary tissue injury, and decreased neutrophil infiltration into the lungs during established melioidosis. Moreover, these mice displayed a delayed mortality as compared to control mice. In conclusion, sustained production of OPN impairs host defense during melioidosis.
Collapse
Affiliation(s)
- Gerritje J. W. van der Windt
- Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, The Netherlands
- Center for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - W. Joost Wiersinga
- Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, The Netherlands
- Center for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Catharina W. Wieland
- Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, The Netherlands
- Center for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Ivo C. S. I. Tjia
- Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, The Netherlands
- Center for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Nicholas P. Day
- Mahidol University, Bangkok, Thailand
- Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, Oxford, United Kingdom
| | - Sharon J. Peacock
- Mahidol University, Bangkok, Thailand
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Sandrine Florquin
- Department of Pathology, Academic Medical Center, Amsterdam, The Netherlands
| | - Tom van der Poll
- Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, The Netherlands
- Center for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam, The Netherlands
- * E-mail:
| |
Collapse
|