1
|
Lu H. Inflammatory liver diseases and susceptibility to sepsis. Clin Sci (Lond) 2024; 138:435-487. [PMID: 38571396 DOI: 10.1042/cs20230522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 01/09/2024] [Accepted: 03/12/2024] [Indexed: 04/05/2024]
Abstract
Patients with inflammatory liver diseases, particularly alcohol-associated liver disease and metabolic dysfunction-associated fatty liver disease (MAFLD), have higher incidence of infections and mortality rate due to sepsis. The current focus in the development of drugs for MAFLD is the resolution of non-alcoholic steatohepatitis and prevention of progression to cirrhosis. In patients with cirrhosis or alcoholic hepatitis, sepsis is a major cause of death. As the metabolic center and a key immune tissue, liver is the guardian, modifier, and target of sepsis. Septic patients with liver dysfunction have the highest mortality rate compared with other organ dysfunctions. In addition to maintaining metabolic homeostasis, the liver produces and secretes hepatokines and acute phase proteins (APPs) essential in tissue protection, immunomodulation, and coagulation. Inflammatory liver diseases cause profound metabolic disorder and impairment of energy metabolism, liver regeneration, and production/secretion of APPs and hepatokines. Herein, the author reviews the roles of (1) disorders in the metabolism of glucose, fatty acids, ketone bodies, and amino acids as well as the clearance of ammonia and lactate in the pathogenesis of inflammatory liver diseases and sepsis; (2) cytokines/chemokines in inflammatory liver diseases and sepsis; (3) APPs and hepatokines in the protection against tissue injury and infections; and (4) major nuclear receptors/signaling pathways underlying the metabolic disorders and tissue injuries as well as the major drug targets for inflammatory liver diseases and sepsis. Approaches that focus on the liver dysfunction and regeneration will not only treat inflammatory liver diseases but also prevent the development of severe infections and sepsis.
Collapse
Affiliation(s)
- Hong Lu
- Department of Pharmacology, SUNY Upstate Medical University, Syracuse, NY 13210, U.S.A
| |
Collapse
|
2
|
Wu X, Yang L, Wu Y, Li H, Shao B. Spread of multidrug-resistant Pseudomonas aeruginosa in animal-derived foods in Beijing, China. Int J Food Microbiol 2023; 403:110296. [PMID: 37392610 DOI: 10.1016/j.ijfoodmicro.2023.110296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 06/04/2023] [Accepted: 06/16/2023] [Indexed: 07/03/2023]
Abstract
Pseudomonas aeruginosa is the most common bacterium occurred in nosocomial infections and is also an important indicator of food spoilage. The worldwide spread of multidrug resistant (MDR) P. aeruginosa is threatening public health. However, the prevalence and spread of MDR P. aeruginosa through the food chain is little referred under the One Health perspective. Here, we collected a total of 259 animal-derived foods (168 chicken and 91 pork) from 16 supermarkets and farmer's markets in six regions of Beijing, China. The prevalence of P. aeruginosa in chicken and pork was 42.1 %. The phenotypic antimicrobial susceptibility testing showed that 69.7 % of isolates were MDR, and isolates from Chaoyang district exhibited a higher resistance rate compared to that from Xicheng district (p < 0.05). P. aeruginosa isolates exhibited high levels of resistance against β-lactams (91.7 %), cephalosporins (29.4 %), and carbapenems (22.9 %). Interestingly, none of strains showed resistance to amikacin. Whole-genome sequencing showed that all isolates carried various kinds of antimicrobial resistance genes (ARGs) and virulence genes (VGs), especially for blaOXA genes and phz genes. Multilocus sequence typing (MLST) analysis indicated that ST111 (12.8 %) was the most predominant ST. Notably, the emergence of ST697 clones in food-borne P. aeruginosa was firstly reported. In addition, the toxin pyocyanin was detected in 79.8 % of P. aeruginosa strains. These findings help to decipher the prevalence and the strong toxigenic ability of MDR P. aeruginosa from animal-derived foods and highlight the effective supervision of animal-derived food hygiene should be strengthened to prevent the spread of ARGs in a One Health strategy.
Collapse
Affiliation(s)
- Xuan Wu
- School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, Beijing Center for Disease Prevention and Control, Beijing 100013, China
| | - Lu Yang
- Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, Beijing Center for Disease Prevention and Control, Beijing 100013, China; National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yige Wu
- Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, Beijing Center for Disease Prevention and Control, Beijing 100013, China; National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Hui Li
- Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, Beijing Center for Disease Prevention and Control, Beijing 100013, China.
| | - Bing Shao
- Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, Beijing Center for Disease Prevention and Control, Beijing 100013, China.
| |
Collapse
|
3
|
Significance of Pulmonary Endothelial Injury and the Role of Cyclooxygenase-2 and Prostanoid Signaling. BIOENGINEERING (BASEL, SWITZERLAND) 2023; 10:bioengineering10010117. [PMID: 36671689 PMCID: PMC9855370 DOI: 10.3390/bioengineering10010117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 01/11/2023] [Accepted: 01/13/2023] [Indexed: 01/19/2023]
Abstract
The endothelium plays a key role in the dynamic balance of hemodynamic, humoral and inflammatory processes in the human body. Its central importance and the resulting therapeutic concepts are the subject of ongoing research efforts and form the basis for the treatment of numerous diseases. The pulmonary endothelium is an essential component for the gas exchange in humans. Pulmonary endothelial dysfunction has serious consequences for the oxygenation and the gas exchange in humans with the potential of consecutive multiple organ failure. Therefore, in this review, the dysfunction of the pulmonary endothel due to viral, bacterial, and fungal infections, ventilator-related injury, and aspiration is presented in a medical context. Selected aspects of the interaction of endothelial cells with primarily alveolar macrophages are reviewed in more detail. Elucidation of underlying causes and mechanisms of damage and repair may lead to new therapeutic approaches. Specific emphasis is placed on the processes leading to the induction of cyclooxygenase-2 and downstream prostanoid-based signaling pathways associated with this enzyme.
Collapse
|
4
|
Wood SJ, Goldufsky JW, Seu MY, Dorafshar AH, Shafikhani SH. Pseudomonas aeruginosa Cytotoxins: Mechanisms of Cytotoxicity and Impact on Inflammatory Responses. Cells 2023; 12:cells12010195. [PMID: 36611990 PMCID: PMC9818787 DOI: 10.3390/cells12010195] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/01/2022] [Accepted: 12/01/2022] [Indexed: 01/05/2023] Open
Abstract
Pseudomonas aeruginosa is one of the most virulent opportunistic Gram-negative bacterial pathogens in humans. It causes many acute and chronic infections with morbidity and mortality rates as high as 40%. P. aeruginosa owes its pathogenic versatility to a large arsenal of cell-associated and secreted virulence factors which enable this pathogen to colonize various niches within hosts and protect it from host innate immune defenses. Induction of cytotoxicity in target host cells is a major virulence strategy for P. aeruginosa during the course of infection. P. aeruginosa has invested heavily in this strategy, as manifested by a plethora of cytotoxins that can induce various forms of cell death in target host cells. In this review, we provide an in-depth review of P. aeruginosa cytotoxins based on their mechanisms of cytotoxicity and the possible consequences of their cytotoxicity on host immune responses.
Collapse
Affiliation(s)
- Stephen J. Wood
- Department of Medicine, Division of Hematology, Oncology and Cell Therapy, Rush University Medical Center, Chicago, IL 60612, USA
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Rush University Medical Center, Chicago, IL 60612, USA
| | - Josef W. Goldufsky
- Department of Medicine, Division of Hematology, Oncology and Cell Therapy, Rush University Medical Center, Chicago, IL 60612, USA
| | - Michelle Y. Seu
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Rush University Medical Center, Chicago, IL 60612, USA
| | - Amir H. Dorafshar
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Rush University Medical Center, Chicago, IL 60612, USA
| | - Sasha H. Shafikhani
- Department of Medicine, Division of Hematology, Oncology and Cell Therapy, Rush University Medical Center, Chicago, IL 60612, USA
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL 60612, USA
- Cancer Center, Rush University Medical Center, Chicago, IL 60612, USA
- Correspondence:
| |
Collapse
|
5
|
Tang H, Yang D, Zhu L, Shi F, Ye G, Guo H, Deng H, Zhao L, Xu Z, Li Y. Paeonol Interferes With Quorum-Sensing in Pseudomonas aeruginosa and Modulates Inflammatory Responses In Vitro and In Vivo. Front Immunol 2022; 13:896874. [PMID: 35686124 PMCID: PMC9170885 DOI: 10.3389/fimmu.2022.896874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/19/2022] [Indexed: 11/19/2022] Open
Abstract
Developing quorum-sensing (QS) based anti-infection drugs is one of the most powerful strategies to combat multidrug-resistant bacteria. Paeonol has been proven to attenuate the QS-controlled virulence factors of P. aeruginosa by down-regulating the transcription of QS signal molecules. This research aimed to assess the anti-virulence activity and mechanism of paeonol against P. aeruginosa infection in vitro and in vivo. In this study, paeonol was found to reduce the adhesion and invasion of P.aeruginosa to macrophages and resist the cytotoxicity induced by P.aeruginosa. Paeonol reduced the expression of virulence factors of P.aeruginosa by inhibiting QS, thereby reducing the LDH release and damage of P.aeruginosa-infected macrophages. Paeonol can inhibit bacterial virulence and enhance the ability of macrophages to clear P.aeruginosa. In addition, paeonol exerts anti-inflammatory activity by reducing the expression of inflammatory cytokines and increasing the production of anti-inflammatory cytokines. Paeonol treatment significantly inhibited the activation of TLR4/MyD88/NF-κB signaling pathway and decreased the inflammation response of P. aeruginosa-infected macrophages. Paeonol also significantly reduced the ability of P.aeruginosa to infect mice and reduced the inflammatory response. These data suggest that paeonol can inhibit the virulence of P.aeruginosa and decrease the inflammation response in P.aeruginosa-infected macrophages and mice, which can decrease the damage induced by P.aeruginosa infection and enhance the ability of macrophages to clear bacteria. This study supports the further development of new potential anti-infective drugs based on inhibition of QS and virulence factors.
Collapse
Affiliation(s)
- Huaqiao Tang
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Dan Yang
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Ling Zhu
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Fei Shi
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Gang Ye
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Hongrui Guo
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Huidan Deng
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Ling Zhao
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Zhiwen Xu
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yinglun Li
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| |
Collapse
|
6
|
CrkII/Abl phosphorylation cascade is critical for NLRC4 inflammasome activity and is blocked by Pseudomonas aeruginosa ExoT. Nat Commun 2022; 13:1295. [PMID: 35277504 PMCID: PMC8917168 DOI: 10.1038/s41467-022-28967-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 02/22/2022] [Indexed: 11/17/2022] Open
Abstract
Type 3 Secretion System (T3SS) is a highly conserved virulence structure that plays an essential role in the pathogenesis of many Gram-negative pathogenic bacteria, including Pseudomonas aeruginosa. Exotoxin T (ExoT) is the only T3SS effector protein that is expressed in all T3SS-expressing P. aeruginosa strains. Here we show that T3SS recognition leads to a rapid phosphorylation cascade involving Abl / PKCδ / NLRC4, which results in NLRC4 inflammasome activation, culminating in inflammatory responses that limit P. aeruginosa infection in wounds. We further show that ExoT functions as the main anti-inflammatory agent for P. aeruginosa in that it blocks the phosphorylation cascade through Abl / PKCδ / NLRC4 by targeting CrkII, which we further demonstrate to be important for Abl transactivation and NLRC4 inflammasome activation in response to T3SS and P. aeruginosa infection. Pseudomonas aeruginosa secretes the toxin ExoT, which is important for pathogenesis. Here, the authors show that ExoT inhibits NLRC4-dependent inflammatory responses during wound infection.
Collapse
|
7
|
Vaccination of mice with hybrid protein containing Exotoxin S and PcrV with adjuvants alum and MPL protects Pseudomonas aeruginosa infections. Sci Rep 2022; 12:1325. [PMID: 35079054 PMCID: PMC8789797 DOI: 10.1038/s41598-022-05157-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 01/07/2022] [Indexed: 11/28/2022] Open
Abstract
Pseudomonas aeruginosa as a common pathogen causing urinary tract infections (UTIs) has been resistant to different antibiotics and developing an effective vaccine can be an alternative strategy. In the present study, the immunogenicity and protection efficacy of formulations composed of a hybrid protein composed of P. aeruginosa V-antigen (PcrV) and exoenzyme S (ExoS) with alum and MPL were evaluated. The hybrid protein could increase the specific systemic and mucosal immune responses, as well as cellular responses as compared with control groups. Combining of alum or MPL adjuvant with the hybrid protein significantly improved the levels of IgG1, serum IgA, mucosal IgG, and IL-17 as compared to the ExoS.PcrV alone. After bladder challenge with a P. aeruginosa strain, the bacterial loads of bladder and kidneys were significantly decreased in mice received ExoS.PcrV admixed with alum and ExoS.PcrV admixed with MPL than controls. The present study indicated that immunization of mice with a hybrid protein composed of ExoS and PcrV could induce multifactorial immune responses and opsonize the bacteria and decrease the viable bacterial cells. Because P. aeruginosa have caused therapeutic challenges worldwide, our study proposed ExoS.PcrV + alum and ExoS.PcrV + MPL as promising candidates for the prevention of infections caused by P. aeruginosa.
Collapse
|
8
|
Sharbatdaralaei H, Asadi Karam MR, Ahmadi K, Habibi M. Bioinformatics analyses for the designation of a hybrid protein against urinary tract infections caused by Pseudomonas aeruginosa and investigation of the presence of pre-existing antibodies in infected humans. J Biomol Struct Dyn 2021; 40:9081-9095. [PMID: 34014146 DOI: 10.1080/07391102.2021.1924264] [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] [Indexed: 02/08/2023]
Abstract
Pseudomonas aeruginosa is an important pathogen causing urinary tract infections (UTIs) and resistance to antibiotics has increased the need for a vaccine against this bacterium. P. aeruginosa V-antigen (PcrV), which is a component of the type III secretion system, delivers exoenzymes such as exoenzyme S (ExoS) into the host cells. In the present study, we aimed to design and express a hybrid protein composed of PcrV and ExoS from P. aeruginosa using bioinformatics. Finally, pre-existing antibodies were evaluated in sera collected from patients with UTI. The prediction results showed that the hybrid protein ExoS.PcrV had a C-score of -0.85 and Z-score of -5.55 versus C-score of -2.93 and Z-score of -2.65 for PcrV.ExoS. Based on BepiPred and ABCpred, 15 and 14 linear B-cell epitopes, as well as five conformational epitopes were identified in ExoS.PcrV. The interaction between the protein and immune receptor was validated in silico. Molecular docking indicated that the hybrid protein interacted strongly with Toll-like receptor 2. ExoS.PcrV was expressed in pET28a-BL21 and purified with a size of 57 kD by Nickel resins. The protein reacted with all sera collected from humans infected with P. aeruginosa following Western blot. The infected patients produced significantly higher IgG levels against the protein compared to the control as indicated by ELISA. The protein ExoS.PcrV was determined as a promising candidate against UTI caused by P. aeruginosa and the presence of pre-existing antibodies indicated the advantage of the hybrid protein. Evaluation of the efficacy of hybrid protein is ongoing in mice model. Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
| | | | - Khadijeh Ahmadi
- Infectious and Tropical Diseases Research Center, Hormozgan Health Institute, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
| | - Mehri Habibi
- Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran
| |
Collapse
|
9
|
Pseudomonas aeruginosa: An Audacious Pathogen with an Adaptable Arsenal of Virulence Factors. Int J Mol Sci 2021; 22:ijms22063128. [PMID: 33803907 PMCID: PMC8003266 DOI: 10.3390/ijms22063128] [Citation(s) in RCA: 194] [Impact Index Per Article: 64.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/16/2021] [Accepted: 03/16/2021] [Indexed: 12/13/2022] Open
Abstract
Pseudomonas aeruginosa is a dominant pathogen in people with cystic fibrosis (CF) contributing to morbidity and mortality. Its tremendous ability to adapt greatly facilitates its capacity to cause chronic infections. The adaptability and flexibility of the pathogen are afforded by the extensive number of virulence factors it has at its disposal, providing P. aeruginosa with the facility to tailor its response against the different stressors in the environment. A deep understanding of these virulence mechanisms is crucial for the design of therapeutic strategies and vaccines against this multi-resistant pathogen. Therefore, this review describes the main virulence factors of P. aeruginosa and the adaptations it undergoes to persist in hostile environments such as the CF respiratory tract. The very large P. aeruginosa genome (5 to 7 MB) contributes considerably to its adaptive capacity; consequently, genomic studies have provided significant insights into elucidating P. aeruginosa evolution and its interactions with the host throughout the course of infection.
Collapse
|
10
|
Lucas R, Hadizamani Y, Gonzales J, Gorshkov B, Bodmer T, Berthiaume Y, Moehrlen U, Lode H, Huwer H, Hudel M, Mraheil MA, Toque HAF, Chakraborty T, Hamacher J. Impact of Bacterial Toxins in the Lungs. Toxins (Basel) 2020; 12:toxins12040223. [PMID: 32252376 PMCID: PMC7232160 DOI: 10.3390/toxins12040223] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
Bacterial toxins play a key role in the pathogenesis of lung disease. Based on their structural and functional properties, they employ various strategies to modulate lung barrier function and to impair host defense in order to promote infection. Although in general, these toxins target common cellular signaling pathways and host compartments, toxin- and cell-specific effects have also been reported. Toxins can affect resident pulmonary cells involved in alveolar fluid clearance (AFC) and barrier function through impairing vectorial Na+ transport and through cytoskeletal collapse, as such, destroying cell-cell adhesions. The resulting loss of alveolar-capillary barrier integrity and fluid clearance capacity will induce capillary leak and foster edema formation, which will in turn impair gas exchange and endanger the survival of the host. Toxins modulate or neutralize protective host cell mechanisms of both the innate and adaptive immunity response during chronic infection. In particular, toxins can either recruit or kill central players of the lung's innate immune responses to pathogenic attacks, i.e., alveolar macrophages (AMs) and neutrophils. Pulmonary disorders resulting from these toxin actions include, e.g., acute lung injury (ALI), the acute respiratory syndrome (ARDS), and severe pneumonia. When acute infection converts to persistence, i.e., colonization and chronic infection, lung diseases, such as bronchitis, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) can arise. The aim of this review is to discuss the impact of bacterial toxins in the lungs and the resulting outcomes for pathogenesis, their roles in promoting bacterial dissemination, and bacterial survival in disease progression.
Collapse
Affiliation(s)
- Rudolf Lucas
- Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Department of Medicine and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Correspondence: (R.L.); (J.H.); Tel.: +41-31-300-35-00 (J.H.)
| | - Yalda Hadizamani
- Lungen-und Atmungsstiftung, Bern, 3012 Bern, Switzerland;
- Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, 3012 Bern, Switzerland
| | - Joyce Gonzales
- Department of Medicine and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Boris Gorshkov
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Thomas Bodmer
- Labormedizinisches Zentrum Dr. Risch, Waldeggstr. 37 CH-3097 Liebefeld, Switzerland;
| | - Yves Berthiaume
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada;
| | - Ueli Moehrlen
- Pediatric Surgery, University Children’s Hospital, Zürich, Steinwiesstrasse 75, CH-8032 Zürch, Switzerland;
| | - Hartmut Lode
- Insitut für klinische Pharmakologie, Charité, Universitätsklinikum Berlin, Reichsstrasse 2, D-14052 Berlin, Germany;
| | - Hanno Huwer
- Department of Cardiothoracic Surgery, Voelklingen Heart Center, 66333 Voelklingen/Saar, Germany;
| | - Martina Hudel
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Mobarak Abu Mraheil
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Haroldo Alfredo Flores Toque
- Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Trinad Chakraborty
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Jürg Hamacher
- Lungen-und Atmungsstiftung, Bern, 3012 Bern, Switzerland;
- Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, 3012 Bern, Switzerland
- Medical Clinic V-Pneumology, Allergology, Intensive Care Medicine and Environmental Medicine, Faculty of Medicine, Saarland University, University Medical Centre of the Saarland, D-66421 Homburg, Germany
- Institute for Clinical & Experimental Surgery, Faculty of Medicine, Saarland University, D-66421 Homburg, Germany
- Correspondence: (R.L.); (J.H.); Tel.: +41-31-300-35-00 (J.H.)
| |
Collapse
|
11
|
Arora S, Ahmad S, Irshad R, Goyal Y, Rafat S, Siddiqui N, Dev K, Husain M, Ali S, Mohan A, Syed MA. TLRs in pulmonary diseases. Life Sci 2019; 233:116671. [PMID: 31336122 PMCID: PMC7094289 DOI: 10.1016/j.lfs.2019.116671] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/16/2019] [Accepted: 07/19/2019] [Indexed: 12/21/2022]
Abstract
Toll-like receptors (TLRs) comprise a clan of proteins involved in identification and triggering a suitable response against pathogenic attacks. As lung is steadily exposed to multiple infectious agents, antigens and host-derived danger signals, the inhabiting stromal and myeloid cells of the lung express an aggregate of TLRs which perceive the endogenously derived damage-associated molecular patterns (DAMPs) along with pathogen associated molecular patterns (PAMPs) and trigger the TLR-associated signalling events involved in host defence. Thus, they form an imperative component of host defence activation in case of microbial infections as well as non-infectious pulmonary disorders such as interstitial lung disease, acute lung injury and airways disease, such as COPD and asthma. They also play an equally important role in lung cancer. Targeting the TLR signalling network would pave ways to the design of more reliable and effective vaccines against infectious agents and control deadly infections, desensitize allergens and reduce inflammation. Moreover, TLR agonists may act as adjuvants by increasing the efficiency of cancer vaccines, thereby contributing their role in treatment of lung cancer too. Overall, TLRs present a compelling and expeditiously bolstered area of research and addressing their signalling events would be of significant use in pulmonary diseases.
Collapse
Affiliation(s)
- Shweta Arora
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
| | - Shaniya Ahmad
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
| | - Rasha Irshad
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
| | - Yamini Goyal
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
| | - Sahar Rafat
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
| | - Neha Siddiqui
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
| | - Kapil Dev
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
| | - Mohammad Husain
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
| | - Shakir Ali
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, India.
| | - Anant Mohan
- Department of Pulmonary Medicine, AIIMS, New Delhi, India.
| | - Mansoor Ali Syed
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
| |
Collapse
|
12
|
Torrens G, Barceló IM, Pérez-Gallego M, Escobar-Salom M, Tur-Gracia S, Munar-Bestard M, González-Nicolau MDM, Cabrera-Venegas YJ, Rigo-Rumbos EN, Cabot G, López-Causapé C, Rojo-Molinero E, Oliver A, Juan C. Profiling the susceptibility of Pseudomonas aeruginosa strains from acute and chronic infections to cell-wall-targeting immune proteins. Sci Rep 2019; 9:3575. [PMID: 30837659 PMCID: PMC6401076 DOI: 10.1038/s41598-019-40440-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 02/06/2019] [Indexed: 02/06/2023] Open
Abstract
In the current scenario of high antibiotic resistance, the search for therapeutic options against Pseudomonas aeruginosa must be approached from different perspectives: cell-wall biology as source of bacterial weak points and our immune system as source of weapons. Our recent study suggests that once the permeability barrier has been overcome, the activity of our cell-wall-targeting immune proteins is notably enhanced, more in mutants with impaired peptidoglycan recycling. The present work aims at analyzing the activity of these proteins [lysozyme and Peptidoglycan-Recognition-Proteins (PGLYRPs)], alone or with a permeabilizer (subinhibitory colistin) in clinical strains, along with other features related to the cell-wall. We compared the most relevant and complementary scenarios: acute (bacteremia) and chronic infections [early/late isolates from lungs of cystic fibrosis (CF) patients]. Although a low activity of lysozyme/PGLYRPs per se (except punctual highly susceptible strains) was found, the colistin addition significantly increased their activity regardless of the strains’ colistin resistance levels. Our results show increased susceptibility in late CF isolates, suggesting that CF adaptation renders P. aeruginosa more vulnerable to proteins targeting the cell-wall. Thus, our work suggests that attacking some P. aeruginosa cell-wall biology-related elements to increase the activity of our innate weapons could be a promising therapeutic strategy.
Collapse
Affiliation(s)
- Gabriel Torrens
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitari Son Espases-Institut de Investigació Sanitària de Balears (IdISBa), Palma, Spain
| | - Isabel M Barceló
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitari Son Espases-Institut de Investigació Sanitària de Balears (IdISBa), Palma, Spain
| | - Marcelo Pérez-Gallego
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitari Son Espases-Institut de Investigació Sanitària de Balears (IdISBa), Palma, Spain
| | - Maria Escobar-Salom
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitari Son Espases-Institut de Investigació Sanitària de Balears (IdISBa), Palma, Spain
| | - Sara Tur-Gracia
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitari Son Espases-Institut de Investigació Sanitària de Balears (IdISBa), Palma, Spain
| | - Marta Munar-Bestard
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitari Son Espases-Institut de Investigació Sanitària de Balears (IdISBa), Palma, Spain
| | - María Del Mar González-Nicolau
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitari Son Espases-Institut de Investigació Sanitària de Balears (IdISBa), Palma, Spain
| | - Yoandy José Cabrera-Venegas
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitari Son Espases-Institut de Investigació Sanitària de Balears (IdISBa), Palma, Spain
| | - Estefany Nayarith Rigo-Rumbos
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitari Son Espases-Institut de Investigació Sanitària de Balears (IdISBa), Palma, Spain
| | - Gabriel Cabot
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitari Son Espases-Institut de Investigació Sanitària de Balears (IdISBa), Palma, Spain
| | - Carla López-Causapé
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitari Son Espases-Institut de Investigació Sanitària de Balears (IdISBa), Palma, Spain
| | - Estrella Rojo-Molinero
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitari Son Espases-Institut de Investigació Sanitària de Balears (IdISBa), Palma, Spain
| | - Antonio Oliver
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitari Son Espases-Institut de Investigació Sanitària de Balears (IdISBa), Palma, Spain
| | - Carlos Juan
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitari Son Espases-Institut de Investigació Sanitària de Balears (IdISBa), Palma, Spain.
| |
Collapse
|
13
|
Banerjee M, Moulick S, Bhattacharya KK, Parai D, Chattopadhyay S, Mukherjee SK. Attenuation of Pseudomonas aeruginosa quorum sensing, virulence and biofilm formation by extracts of Andrographis paniculata. Microb Pathog 2017; 113:85-93. [PMID: 29042302 DOI: 10.1016/j.micpath.2017.10.023] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 08/19/2017] [Accepted: 10/13/2017] [Indexed: 02/08/2023]
Abstract
Quorum-sensing (QS) is known to play an essential role in regulation of virulence factors and toxins during Pseudomonas aeruginosa infection which may frequently cause antibiotic resistance and hostile outcomes of inflammatory injury. Therefore, it is an urgent need to search for a novel agent with low risk of resistance development that can target QS and inflammatory damage prevention as well. Andrographis paniculata, a herbaceous plant under the family Acanthaceae, native to Asian countries and also cultivated in Scandinavia and some parts of Europe, has a strong traditional usage with its known antibacterial, anti-inflammatory, antipyretic, antiviral and antioxidant properties. In this study, three different solvent extracts (viz., chloroform, methanol and aqueous) of A. paniculata were examined for their anti-QS and anti-inflammatory activities. Study was carried out to assess the effect on some selected QS-regulatory genes at transcriptional level using Real Time-PCR. In addition, ability to attenuate MAPK pathways upon P. aeruginosa infection was performed to check its potential anti-inflammatory activity. Chloroform and methanol extracts showed significant reduction (p < 0.05) of the QS-controlled extracellular virulence factors in P. aeruginosa including the expression of pyocyanin, elastase, total protease, rhamnolipid and hemolysin without affecting bacterial viability. They also significantly (p < 0.05) reduced swarming motility and biofilm formation of P. aeruginosa. The chloroform extract, which was found to be more effective, decreased expression of lasI, lasR, rhlI and rhlR by 61%, 75%, 41%, and 44%, respectively. Moreover, chloroform extract decreased activation of p-p38 and p-ERK1/2 expression levels in MAPK signal pathways in P. aeruginosa infected macrophage cells. As the present study demonstrates that A. paniculata extracts inhibit QS in P. aeruginosa and exhibit anti-inflammatory activities, therefore it represents itself as a prospective therapeutic agent against P. aeruginosa infection.
Collapse
Affiliation(s)
- Malabika Banerjee
- Department of Microbiology, University of Kalyani, Kalyani 741235, WB, India; TCG Life Sciences Ltd., Bengal Intelligent Park, Tower-B, Block-EP & GP, Sector-5, Salt Lake, Kolkata 700091, India
| | - Soumitra Moulick
- TCG Life Sciences Ltd., Bengal Intelligent Park, Tower-B, Block-EP & GP, Sector-5, Salt Lake, Kolkata 700091, India
| | - Kunal Kumar Bhattacharya
- TCG Life Sciences Ltd., Bengal Intelligent Park, Tower-B, Block-EP & GP, Sector-5, Salt Lake, Kolkata 700091, India
| | - Debaprasad Parai
- Department of Microbiology, University of Kalyani, Kalyani 741235, WB, India
| | - Subrata Chattopadhyay
- TCG Life Sciences Ltd., Bengal Intelligent Park, Tower-B, Block-EP & GP, Sector-5, Salt Lake, Kolkata 700091, India
| | | |
Collapse
|
14
|
Li R, Fang L, Tan S, Yu M, Li X, He S, Wei Y, Li G, Jiang J, Wu M. Type I CRISPR-Cas targets endogenous genes and regulates virulence to evade mammalian host immunity. Cell Res 2016; 26:1273-1287. [PMID: 27857054 DOI: 10.1038/cr.2016.135] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 07/29/2016] [Accepted: 08/29/2016] [Indexed: 02/05/2023] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated (Cas) systems in bacteria and archaea provide adaptive immunity against invading foreign nucleic acids. Previous studies suggest that certain bacteria employ their Type II CRISPR-Cas systems to target their own genes, thus evading host immunity. However, whether other CRISPR-Cas systems have similar functions during bacterial invasion of host cells remains unknown. Here we identify a novel role for Type I CRISPR-Cas systems in evading host defenses in Pseudomonas aeruginosa strain UCBPP-PA14. The Type I CRISPR-Cas system of PA14 targets the mRNA of the bacterial quorum-sensing regulator LasR to dampen the recognition by toll-like receptor 4, thus diminishing the pro-inflammatory responses of the host in cell and mouse models. Mechanistically, this nuclease-mediated RNA degradation requires a "5'-GGN-3'" recognition motif in the target mRNA, and HD and DExD/H domains in Cas3 of the Type I CRISPR-Cas system. As LasR and Type I CRISPR-Cas systems are ubiquitously present in bacteria, our findings elucidate an important common mechanism underlying bacterial virulence.
Collapse
Affiliation(s)
- Rongpeng Li
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203-9061, USA
| | - Lizhu Fang
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203-9061, USA
| | - Shirui Tan
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203-9061, USA
| | - Min Yu
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203-9061, USA.,State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan 610041, China
| | - Xuefeng Li
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203-9061, USA.,State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan 610041, China
| | - Sisi He
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203-9061, USA.,State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan 610041, China
| | - Yuquan Wei
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan 610041, China
| | - Guoping Li
- Inflammations & Allergic Diseases Research Unit, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646004, China
| | - Jianxin Jiang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing 400042, China
| | - Min Wu
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203-9061, USA.,State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan 610041, China
| |
Collapse
|
15
|
c- Src and its role in cystic fibrosis. Eur J Cell Biol 2016; 95:401-413. [DOI: 10.1016/j.ejcb.2016.08.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 08/08/2016] [Accepted: 08/10/2016] [Indexed: 12/15/2022] Open
|
16
|
Ralhan A, Laval J, Lelis F, Ballbach M, Grund C, Hector A, Hartl D. Current Concepts and Controversies in Innate Immunity of Cystic Fibrosis Lung Disease. J Innate Immun 2016; 8:531-540. [PMID: 27362371 PMCID: PMC6738757 DOI: 10.1159/000446840] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 05/17/2016] [Accepted: 05/17/2016] [Indexed: 12/11/2022] Open
Abstract
Cystic fibrosis (CF) lung disease is characterized by chronic infection and inflammation. The inflammatory response in CF is dominated by the activation of the innate immune system. Bacteria and fungi represent the key pathogens chronically colonizing the CF airways. In response, innate immune pattern recognition receptors, expressed by airway epithelial and myeloid cells, sense the microbial threat and release chemoattractants to recruit large numbers of neutrophils into CF airways. However, neutrophils fail to efficiently clear the invading pathogens, but instead release harmful proteases and oxidants and finally cause tissue injury. Here, we summarize and discuss current concepts and controversies in the field of innate immunity in CF lung disease, facing the ongoing questions of whether inflammation is good or bad in CF and how innate immune mechanisms could be harnessed therapeutically.
Collapse
Affiliation(s)
- Anjali Ralhan
- Department of Pediatrics I, University of Tübingen, Tübingen, Germany
| | - Julie Laval
- Department of Pediatrics I, University of Tübingen, Tübingen, Germany
| | - Felipe Lelis
- Department of Pediatrics I, University of Tübingen, Tübingen, Germany
| | - Marlene Ballbach
- Department of Pediatrics I, University of Tübingen, Tübingen, Germany
| | - Charlotte Grund
- Department of Pediatrics I, University of Tübingen, Tübingen, Germany
| | - Andreas Hector
- Department of Pediatrics I, University of Tübingen, Tübingen, Germany
| | - Dominik Hartl
- Department of Pediatrics I, University of Tübingen, Tübingen, Germany
- Immunology, Inflammation and Infectious Diseases (I3) Discovery and Translational Area, Roche Pharma Research and Early Development (pRED), Roche Innovation Center Basel, Basel, Switzerland
| |
Collapse
|
17
|
Luo J, Kong JL, Dong BY, Huang H, Wang K, Wu LH, Hou CC, Liang Y, Li B, Chen YQ. Baicalein attenuates the quorum sensing-controlled virulence factors of Pseudomonas aeruginosa and relieves the inflammatory response in P. aeruginosa-infected macrophages by downregulating the MAPK and NFκB signal-transduction pathways. DRUG DESIGN DEVELOPMENT AND THERAPY 2016; 10:183-203. [PMID: 26792984 PMCID: PMC4708194 DOI: 10.2147/dddt.s97221] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Burgeoning antibiotic resistance and unfavorable outcomes of inflammatory injury after Pseudomonas aeruginosa infection have necessitated the development of novel agents that not only target quorum sensing (QS) but also combat inflammatory injury with the least risk of resistance. This study aimed to assess the anti-QS and anti-inflammatory activities of baicalein, a traditional herbal medicine that is widely used in the People’s Republic of China, against P. aeruginosa infection. We found that subminimum inhibitory concentrations of baicalein efficiently interfered with the QS-signaling pathway of P. aeruginosa via downregulation of the transcription of QS-regulated genes and the translation of QS-signaling molecules. This interference resulted in the global attenuation of QS-controlled virulence factors, such as motility and biofilm formation, and the secretion into the culture supernatant of extracellular virulence factors, including pyocyanin, LasA protease, LasB elastase, and rhamnolipids. Moreover, we examined the anti-inflammatory activity of baicalein and its mode of action via a P. aeruginosa-infected macrophage model to address its therapeutic effect. Baicalein reduced the P. aeruginosa-induced secretion of the inflammatory cytokines IL-1β, IL-6, IL-8, and TNFα. In addition, baicalein suppressed P. aeruginosa-induced activation of the MAPK and NFκB signal-transduction pathways in cocultured macrophages; this may be the mechanism by which baicalein inhibits the production of proinflammatory cytokines. Therefore, our study demonstrates that baicalein represents a potential treatment for P. aeruginosa infection because it clearly exhibits both antibacterial and anti-inflammatory activities.
Collapse
Affiliation(s)
- Jing Luo
- Department of Respiratory Disease, First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| | - Jin-Liang Kong
- Department of Respiratory Disease, First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| | - Bi-Ying Dong
- Department of Respiratory Disease, First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| | - Hong Huang
- Department of Respiratory Disease, First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| | - Ke Wang
- Department of Respiratory Disease, First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| | - Li-Hong Wu
- Department of Respiratory Disease, First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| | - Chang-Chun Hou
- Department of Respiratory Disease, First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| | - Yue Liang
- Department of Respiratory Disease, First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| | - Bing Li
- Department of Respiratory Disease, First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| | - Yi-Qiang Chen
- Department of Respiratory Disease, First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| |
Collapse
|
18
|
Lagae S, Dumont A, Vanrompay D. Examination of the in vivo immune response elicited by Chlamydia psittaci in chickens. Vet Immunol Immunopathol 2015; 170:54-64. [PMID: 26848049 DOI: 10.1016/j.vetimm.2015.09.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Revised: 09/07/2015] [Accepted: 09/18/2015] [Indexed: 02/05/2023]
Abstract
It has since long been reported that Chlamydia psittaci is endemic in the poultry industry in Belgium as well as in other European Countries. This can lead to major economic losses because of a lowered egg production, higher mortality and carcass condemnation. Nowadays, expensive antibiotic treatments are necessary to reduce mortality rate but this can lead to antibiotic resistance. Moreover, C. psittaci can easily be transmitted from birds to humans through the inhalation of pathogen-containing aerosols derived from feces and eye and nostril secretions. Therefore, the need for an efficient vaccine against C. psittaci is augmenting. However, more research is needed to develop such a vaccine. Knowledge on the immune mechanisms of C. psittaci infections is crucial to understand the pathogenesis of, and immunity to this zoonotic pathogen and to act as a basis for vaccination studies. This study has investigated the in vivo immune response evoked by C. psittaci in his natural host, the chicken. Excretion of C. psittaci, chlamydial antibody detection in sera, blood immune cells and the mRNA expression levels of different cytokines, chemokines and one Toll-like receptor were investigated in different organs (conchae, lungs, airsacs, harderian gland, bursa fabricius and spleen) at different time points post infection (6 h, 24 h, 48 h, 4 d, 6d, 8 d, 10 d, 14 d and 21 d). A higher frequency of cytotoxic CD8(+) T cells and monocytes/macrophages expressing the MHC II molecule were observed in the infected group. Several cytokines and chemokines are significantly upregulated during infection but remarkably also significantly downregulated, especially at late time points. Furthermore, the only Toll-like receptor investigated, TLR4, was also significant upregulated in several organs. This study can contribute on the elucidation on how C. psittaci interact with his host, leading to the developing of targets for effective vaccination and therapeutic strategies for infection.
Collapse
|
19
|
The Poly-γ-d-Glutamic Acid Capsule Surrogate of the Bacillus anthracis Capsule Is a Novel Toll-Like Receptor 2 Agonist. Infect Immun 2015. [PMID: 26195551 DOI: 10.1128/iai.00888-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Bacillus anthracis is a pathogenic Gram-positive bacterium that causes a highly lethal infectious disease, anthrax. The poly-γ-d-glutamic acid (PGA) capsule is one of the major virulence factors of B. anthracis, along with exotoxins. PGA enables B. anthracis to escape phagocytosis and immune surveillance. Our previous study showed that PGA activates the human macrophage cell line THP-1 and human dendritic cells, resulting in the production of the proinflammatory cytokine interleukin-1β (IL-1β) (M. H. Cho et al., Infect Immun 78:387-392, 2010, http://dx.doi.org/10.1128/IAI.00956-09). Here, we investigated PGA-induced cytokine responses and related signaling pathways in mouse bone marrow-derived macrophages (BMDMs) using Bacillus licheniformis PGA as a surrogate for B. anthracis PGA. Upon exposure to PGA, BMDMs produced proinflammatory mediators, including tumor necrosis factor alpha (TNF-α), IL-6, IL-12p40, and monocyte chemoattractant protein 1 (MCP-1), in a concentration-dependent manner. PGA stimulated Toll-like receptor 2 (TLR2) but not TLR4 in Chinese hamster ovary cells expressing either TLR2 or TLR4. The ability of PGA to induce TNF-α and IL-6 was retained in TLR4(-/-) but not TLR2(-/-) BMDMs. Blocking experiments with specific neutralizing antibodies for TLR1, TLR6, and CD14 showed that TLR6 and CD14 also were necessary for PGA-induced inflammatory responses. Furthermore, PGA enhanced activation of mitogen-activated protein (MAP) kinases and nuclear factor-kappa B (NF-κB), which are responsible for expression of proinflammatory cytokines. Additionally, PGA-induced TNF-α production was abrogated not only in MyD88(-/-) BMDMs but also in BMDMs pretreated with inhibitors of MAP kinases and NF-κB. These results suggest that immune responses induced by PGA occur via TLR2, TLR6, CD14, and MyD88 through activation of MAP kinase and NF-κB pathways.
Collapse
|
20
|
Ezzat Alnakip M, Quintela-Baluja M, Böhme K, Fernández-No I, Caamaño-Antelo S, Calo-Mata P, Barros-Velázquez J. The Immunology of Mammary Gland of Dairy Ruminants between Healthy and Inflammatory Conditions. J Vet Med 2014; 2014:659801. [PMID: 26464939 PMCID: PMC4590879 DOI: 10.1155/2014/659801] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 09/24/2014] [Indexed: 01/01/2023] Open
Abstract
The health of dairy animals, particularly the milk-producing mammary glands, is essential to the dairy industry because of the crucial hygienic and economic aspects of ensuring production of high quality milk. Due to its high prevalence, mastitis is considered the most important threat to dairy industry, due to its impacts on animal health and milk production and thus on economic benefits. The MG is protected by several defence mechanisms that prevent microbial penetration and surveillance. However, several factors can attenuate the host immune response (IR), and the possession of various virulence and resistance factors by different mastitis-causing microorganisms greatly limits immune defences and promotes establishment of intramammary infections (IMIs). A comprehensive understanding of MG immunity in both healthy and inflammatory conditions will be an important key to understand the nature of IMIs caused by specific pathogens and greatly contributes to the development of effective control methods and appropriate detection techniques. Consequently, this review aims to provide a detailed overview of antimicrobial defences in the MG under healthy and inflammatory conditions. In this sense, we will focus on pathogen-dependent variations in IRs mounted by the host during IMI and discuss the potential ramifications of these variations.
Collapse
Affiliation(s)
- Mohamed Ezzat Alnakip
- Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences/College of Biotechnology, University of Santiago de Compostela, Campus Lugo, Rúa Carballo Calero, 27002 Lugo, Spain
- Food Control Department, Dairy Division, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Al Sharkia 44519, Egypt
| | - Marcos Quintela-Baluja
- Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences/College of Biotechnology, University of Santiago de Compostela, Campus Lugo, Rúa Carballo Calero, 27002 Lugo, Spain
| | - Karola Böhme
- Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences/College of Biotechnology, University of Santiago de Compostela, Campus Lugo, Rúa Carballo Calero, 27002 Lugo, Spain
| | - Inmaculada Fernández-No
- Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences/College of Biotechnology, University of Santiago de Compostela, Campus Lugo, Rúa Carballo Calero, 27002 Lugo, Spain
| | - Sonia Caamaño-Antelo
- Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences/College of Biotechnology, University of Santiago de Compostela, Campus Lugo, Rúa Carballo Calero, 27002 Lugo, Spain
| | - Pillar Calo-Mata
- Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences/College of Biotechnology, University of Santiago de Compostela, Campus Lugo, Rúa Carballo Calero, 27002 Lugo, Spain
| | - Jorge Barros-Velázquez
- Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences/College of Biotechnology, University of Santiago de Compostela, Campus Lugo, Rúa Carballo Calero, 27002 Lugo, Spain
| |
Collapse
|
21
|
Bednarska K, Kielbik M, Sulowska Z, Dziadek J, Klink M. Cholesterol oxidase binds TLR2 and modulates functional responses of human macrophages. Mediators Inflamm 2014; 2014:498395. [PMID: 25120288 PMCID: PMC4121183 DOI: 10.1155/2014/498395] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 06/18/2014] [Accepted: 06/20/2014] [Indexed: 01/07/2023] Open
Abstract
Cholesterol oxidase (ChoD) is considered to be an important virulence factor for Mycobacterium tuberculosis (Mtb), but its influence on macrophage activity is unknown. Here we used Nocardia erythropolis ChoD, which is very similar to the Mtb enzyme (70% identity at the amino-acid level), to evaluate the impact of bacterial ChoD on the activity of THP-1-derived macrophages in vitro. We found that ChoD decreased the surface expression of Toll-like receptor type 2 (TLR2) and complement receptor 3 (CR3) on these macrophages. Flow cytometry and confocal microscopy showed that ChoD competed with lipoteichoic acid for ligand binding sites on TLR2 but not on CR3, suggesting that ChoD signaling is mediated via TLR2. Binding of ChoD to the membrane of macrophages had diverse effects on the activity of macrophages, activating p38 mitogen activated kinase and stimulating production of a large amount of interleukin-10. Moreover, ChoD primed macrophages to enhance the production of reactive oxygen species in response to the phorbol myristate acetate, which was reduced by "switching off" TLR-derived signaling through interleukin-1 receptor-associated kinases 1 and 4 inhibition. Our study revealed that ChoD interacts directly with macrophages via TLR2 and influences the biological activity of macrophages during the development of the initial response to infection.
Collapse
Affiliation(s)
- Katarzyna Bednarska
- Institute of Medical Biology, Polish Academy of Sciences, Lodowa 106, 93-232 Lodz, Poland
| | - Michal Kielbik
- Institute of Medical Biology, Polish Academy of Sciences, Lodowa 106, 93-232 Lodz, Poland
| | - Zofia Sulowska
- Institute of Medical Biology, Polish Academy of Sciences, Lodowa 106, 93-232 Lodz, Poland
| | - Jaroslaw Dziadek
- Institute of Medical Biology, Polish Academy of Sciences, Lodowa 106, 93-232 Lodz, Poland
| | - Magdalena Klink
- Institute of Medical Biology, Polish Academy of Sciences, Lodowa 106, 93-232 Lodz, Poland
| |
Collapse
|
22
|
Sallenave JM. Phagocytic and signaling innate immune receptors: are they dysregulated in cystic fibrosis in the fight against Pseudomonas aeruginosa? Int J Biochem Cell Biol 2014; 52:103-7. [PMID: 24508137 DOI: 10.1016/j.biocel.2014.01.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 01/12/2014] [Accepted: 01/17/2014] [Indexed: 12/17/2022]
Abstract
Cystic fibrosis (CF) is a genetic disease that affects mainly the lung and the digestive system, causing progressive disability and organ failure. The most prevalent CFTR mutation dF508 (which constitutes 70% of all mutations) results in an incorrect targeting of the CFTR molecule to the membrane. It is now a well-accepted concept that mucosal innate immune responses are dysregulated in cystic fibrosis through a cycle of infectious and inflammatory episodes. However, although much work has focused on the late consequences of chronic lung inflammation in CF, very little is known on the early events leading to infection and colonization, such as that of Pseudomonas aeruginosa (P.a). We review here the involvement of a range of innate phagocytic/signaling receptors in the control of this pathogen (mannose receptor, complement receptor-3, Toll-like receptors, etc.) and evaluate the possibility that the activity of some of these receptors may be dysregulated in cystic fibrosis, potentially explaining the florid infections encountered in this disease.
Collapse
Affiliation(s)
- Jean-Michel Sallenave
- Institut Pasteur, Unité de Défense Innée et Inflammation, Paris, France; INSERM UMR1152 'Physiopathologie et épidémiologie des maladies respiratoires', France; University Paris Diderot, Sorbonne Paris Cité, Paris, France.
| |
Collapse
|
23
|
Roy S, Karmakar M, Pearlman E. CD14 mediates Toll-like receptor 4 (TLR4) endocytosis and spleen tyrosine kinase (Syk) and interferon regulatory transcription factor 3 (IRF3) activation in epithelial cells and impairs neutrophil infiltration and Pseudomonas aeruginosa killing in vivo. J Biol Chem 2013; 289:1174-82. [PMID: 24275652 DOI: 10.1074/jbc.m113.523167] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the current study, we examined the role of CD14 in regulating LPS activation of corneal epithelial cells and Pseudomonas aeruginosa corneal infection. Our findings demonstrate that LPS induces Toll-like receptor 4 (TLR4) internalization in corneal epithelial cells and that blocking with anti-CD14 selectively inhibits TLR4 endocytosis, spleen tyrosine kinase (Syk) and IRF3 phosphorylation, and production of CCL5/RANTES and IFN-β, but not IL-8. Using a murine model of P. aeruginosa corneal infection, we show that although infected CD14(-/-) corneas produce less CCL5, they exhibit significantly increased CXC chemokine production, neutrophil recruitment to the corneal stroma, and bacterial clearance than C57BL/6 mice. We conclude that CD14 has a critical role in mediating TLR4 signaling through IRF3 in resident corneal epithelial cells and macrophages and thereby modulates TLR4 cell surface activation of the MyD88/NF-κB/AP-1 pathway and production of CXC chemokines and neutrophil infiltration to infected tissues.
Collapse
Affiliation(s)
- Sanhita Roy
- From the Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio 44095
| | | | | |
Collapse
|
24
|
Andonova M, Urumova V. Immune surveillance mechanisms of the skin against the stealth infection strategy of Pseudomonas aeruginosa—Review. Comp Immunol Microbiol Infect Dis 2013; 36:433-48. [DOI: 10.1016/j.cimid.2013.03.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 01/21/2013] [Accepted: 03/30/2013] [Indexed: 01/01/2023]
|
25
|
Evolution of Pseudomonas aeruginosa virulence as a result of phage predation. Appl Environ Microbiol 2013; 79:6110-6. [PMID: 23892756 DOI: 10.1128/aem.01421-13] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The rapid increase in the emergence of antibiotic-resistant bacteria has attracted attention to bacteriophages for treating and preventing bacterial infections. Bacteriophages can drive the diversification of Pseudomonas aeruginosa, giving rise to phage-resistant variants with different phenotypes from their ancestral hosts. In this study, we sought to investigate the effect of phage resistance on cytotoxicity of host populations toward cultured mammalian cells. The library of phage-resistant P. aeruginosa PAO1 variants used was developed previously via experimental evolution of an isogenic host population using phages PP7 and E79. Our results presented herein indicate that the phage-resistant variants developed in a heterogeneous phage environment exhibit a greater ability to impede metabolic action of cultured human keratinocytes and have a greater tendency to cause membrane damage even though they cannot invade the cells in large numbers. They also show a heightened resistance to phagocytosis by model murine macrophages. Furthermore, all isolates produced higher levels of at least one of the secreted virulence factors, namely, total proteases, elastase, phospholipase C, and hemolysins. Reverse transcription-quantitative PCR (RT-qPCR) revealed upregulation in the transcription of a number of genes associated with virulence of P. aeruginosa for the phage-resistant variants. The results of this study indicate a significant change in the in vitro virulence of P. aeruginosa following phage predation and highlight the need for caution in the selection and design of phages and phage cocktails for therapeutic use.
Collapse
|
26
|
Galle M, Carpentier I, Beyaert R. Structure and function of the Type III secretion system of Pseudomonas aeruginosa. Curr Protein Pept Sci 2012; 13:831-42. [PMID: 23305368 PMCID: PMC3706959 DOI: 10.2174/138920312804871210] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 07/19/2012] [Accepted: 07/25/2012] [Indexed: 02/08/2023]
Abstract
Pseudomonas aeruginosa is a dangerous pathogen particularly because it harbors multiple virulence factors. It causes several types of infection, including dermatitis, endocarditis, and infections of the urinary tract, eye, ear, bone, joints and, of particular interest, the respiratory tract. Patients with cystic fibrosis, who are extremely susceptible to Pseudomonas infections, have a bad prognosis and high mortality. An important virulence factor of P. aeruginosa, shared with many other gram-negative bacteria, is the type III secretion system, a hollow molecular needle that transfers effector toxins directly from the bacterium into the host cell cytosol. This complex macromolecular machine works in a highly regulated manner and can manipulate the host cell in many different ways. Here we review the current knowledge of the structure of the P. aeruginosa T3SS, as well as its function and recognition by the immune system. Furthermore, we describe recent progress in the development and use of therapeutic agents targeting the T3SS.
Collapse
Affiliation(s)
- Marlies Galle
- Department of Biomedical Molecular Biology, Ghent University, Technologiepark 927, B-9052 Ghent, Belgium; the
- Department for Molecular Biomedical Research, Unit of Molecular Signal Transduction in Inflammation, VIB, Technologiepark 927, B-9052 Ghent, Belgium
| | - Isabelle Carpentier
- Department of Biomedical Molecular Biology, Ghent University, Technologiepark 927, B-9052 Ghent, Belgium; the
- Department for Molecular Biomedical Research, Unit of Molecular Signal Transduction in Inflammation, VIB, Technologiepark 927, B-9052 Ghent, Belgium
| | - Rudi Beyaert
- Department of Biomedical Molecular Biology, Ghent University, Technologiepark 927, B-9052 Ghent, Belgium; the
- Department for Molecular Biomedical Research, Unit of Molecular Signal Transduction in Inflammation, VIB, Technologiepark 927, B-9052 Ghent, Belgium
| |
Collapse
|
27
|
McIsaac SM, Stadnyk AW, Lin TJ. Toll-like receptors in the host defense against Pseudomonas aeruginosa respiratory infection and cystic fibrosis. J Leukoc Biol 2012; 92:977-85. [PMID: 22892106 DOI: 10.1189/jlb.0811410] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
TLRs function in innate immunity by detecting conserved structures present in bacteria, viruses, and fungi. Although TLRs do not necessarily distinguish pathogenic organisms from commensals, in the context of compromised innate immunity and combined with pathogens' effector molecules, TLRs drive the host response to the organism. This review will discuss the evidence and role(s) of TLRs in the response to the opportunistic bacterial pathogen, Pseudomonas aeruginosa, as it relates to respiratory infection and CF, in which innate immune mechanisms are indeed compromised. Outer membrane lipoproteins, LPS, flagellin, and nucleic acids all serve as ligands for TLR2, -4, -5, and -9, respectively. These TLRs and their respective downstream effector molecules have proven critical to the host response to P. aeruginosa, although the protective effects of TLRs may be impaired and in some cases, enhanced in the CF patient, contributing to the particular susceptibility of individuals with this disease to P. aeruginosa infection.
Collapse
Affiliation(s)
- Shayla M McIsaac
- Department of Microbiology, Dalhousie University, Halifax, Nova Scotia, Canada
| | | | | |
Collapse
|
28
|
Chakraborty DC, Mukherjee G, Banerjee P, Banerjee KK, Biswas T. Hemolysin induces Toll-like receptor (TLR)-independent apoptosis and multiple TLR-associated parallel activation of macrophages. J Biol Chem 2011; 286:34542-51. [PMID: 21846723 DOI: 10.1074/jbc.m111.241851] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Vibrio cholerae hemolysin (HlyA) displays bipartite property while supervising macrophages (MΦ). The pore-forming toxin causes profound apoptosis within 3 h of exposure and in parallel supports activation of the defying MΦ. HlyA-induced apoptosis of MΦ remains steady for 24 h, is Toll-like receptor (TLR)-independent, and is driven by caspase-9 and caspase-7, thus involving the mitochondrial or intrinsic pathway. Cell activation is carried forward by time dependent up-regulation of varying TLRs. The promiscuous TLR association of HlyA prompted investigation, which revealed the β-prism lectin domain of HlyA simulated TLR4 up-regulation by jacalin, a plant lectin homologue besides expressing CD86 and type I cytokines TNF-α and IL-12. However, HlyA cytolytic protein domain up-regulated TLR2, which controlled CD40 for continuity of cell activation. Expression of TOLLIP before TLR2 and TLR6 abrogated TLR4, CD40, and CD86. We show that the transient expression of TOLLIP leading to curbing of activation-associated capabilities is a plausible feedback mechanism of MΦ to deploy TLR2 and prolong activation involving CD40 to encounter the HlyA cytolysin domain.
Collapse
Affiliation(s)
- Deep Chandan Chakraborty
- Division of Immunology, National Institute of Cholera and Enteric Diseases, Kolkata 700 010, India
| | | | | | | | | |
Collapse
|
29
|
Dampening Host Sensing and Avoiding Recognition in Pseudomonas aeruginosa Pneumonia. J Biomed Biotechnol 2011; 2011:852513. [PMID: 21785567 PMCID: PMC3139209 DOI: 10.1155/2011/852513] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 05/09/2011] [Indexed: 01/01/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen and causes a wide range of acute and chronic infections. P. aeruginosa infections are kept in check by an effective immune surveillance in the healthy host, while any imbalance or defect in the normal immune response can manifest in disease. Invasive acute infection in the immunocompromised patients is mediated by potent extracellular and cell bound bacterial virulence factors. Life-threatening chronic infection in cystic fibrosis patients is maintained by pathogenic variants that contribute to evade detection and clearance by the immune system. Here, we reviewed the molecular basis of receptor-mediated recognition of P. aeruginosa and their role in initiating inflammation and the colonization. In addition, the consequence of the P. aeruginosa genetic adaptation for the antibacterial defence and the maintaining of chronic infection are discussed.
Collapse
|
30
|
Lafferty EI, Qureshi ST, Schnare M. The role of toll-like receptors in acute and chronic lung inflammation. JOURNAL OF INFLAMMATION-LONDON 2010; 7:57. [PMID: 21108806 PMCID: PMC3003652 DOI: 10.1186/1476-9255-7-57] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Accepted: 11/25/2010] [Indexed: 12/13/2022]
Abstract
By virtue of its direct contact with the environment, the lung is constantly challenged by infectious and non-infectious stimuli that necessitate a robust yet highly controlled host response coordinated by the innate and adaptive arms of the immune system. Mammalian Toll-like receptors (TLRs) function as crucial sentinels of microbial and non-infectious antigens throughout the respiratory tract and mediate host innate immunity. Selective induction of inflammatory responses to harmful environmental exposures and tolerance to innocuous antigens are required to maintain tissue homeostasis and integrity. Conversely, dysregulated innate immune responses manifest as sustained and self-perpetuating tissue damage rather than controlled tissue repair. In this article we review aspects of Toll-like receptor function that are relevant to the development of acute lung injury and chronic obstructive lung diseases as well as resistance to frequently associated microbial infections.
Collapse
Affiliation(s)
- Erin I Lafferty
- Division of Experimental Medicine, McGill University, Montréal, Québec H3A 1A3, Canada.
| | | | | |
Collapse
|
31
|
Moro MR, Bonville CA, Suryadevara M, Cummings E, Faddoul D, Kobayaa H, Branigan PJ, Domachowske JB. Clinical features, adenovirus types, and local production of inflammatory mediators in adenovirus infections. Pediatr Infect Dis J 2009; 28:376-80. [PMID: 19319023 DOI: 10.1097/inf.0b013e31819075a6] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Adenovirus infection manifests in many ways, with respiratory and gastrointestinal symptoms predominating. METHODS We performed a retrospective chart review on children evaluated at our center who had a nasal wash culture positive for adenovirus. Archived nasal washes were retrieved. Polymerase chain reaction for 15 respiratory viruses was performed on these samples. Patients who were coinfected with another virus were excluded. Adenovirus typing was performed using polymerase chain reaction primers directed at the conserved hexon gene. Bead proteomics was used to measure concentrations of inflammatory mediators. RESULTS Seventy-eight patients were infected only with adenovirus. The clinical diagnosis was upper respiratory infection in 60%, pneumonia in 18%, febrile seizure in 8%, and bronchiolitis in 6%. Subgroup-C and B1 infections were most common. Seventy percent of patients with upper respiratory infection and all 5 patients with bronchiolitis had a subgroup-C infection; pneumonia was caused by subgroup-B1 and C viruses. Compared with asymptomatic control patients, adenovirus infected patients had higher nasal wash concentrations of interleukin (IL)-1alpha, IL-6, inducible protein-10, macrophage inflammatory protein-1alpha, tumor necrosis factor alpha, monokine induced by gamma interferon, and interferon-alpha (P < 0.05). In addition, we found that IL-8 and IL-1alpha (P < 0.05) were higher in the nasal washes obtained from hospitalized patients than in nonhospitalized patients. CONCLUSIONS Adenovirus infection causes an array of clinical disease and is associated with local production of several proinflammatory cytokines. The observation that nasal wash IL-8 and IL-1alpha concentrations were higher in patients requiring hospitalization suggests that these mediators contribute to disease severity.
Collapse
Affiliation(s)
- Maria R Moro
- Department of Pediatrics, SUNY Upstate Medical University, Syracuse, NY, USA
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Liang S, Hosur KB, Lu S, Nawar HF, Weber BR, Tapping RI, Connell TD, Hajishengallis G. Mapping of a microbial protein domain involved in binding and activation of the TLR2/TLR1 heterodimer. THE JOURNAL OF IMMUNOLOGY 2009; 182:2978-85. [PMID: 19234193 DOI: 10.4049/jimmunol.0803737] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The pentameric B subunit of type IIb Escherichia coli enterotoxin (LT-IIb-B(5)), a doughnut-shaped oligomeric protein from enterotoxigenic E. coli, activates the TLR2/TLR1 heterodimer (TLR2/1). We investigated the molecular basis of the LT-IIb-B(5) interaction with TLR2/1 to define the structure-function relationship of LT-IIb-B(5) and, moreover, to gain an insight into how TLR2/1 recognizes large, nonacylated protein ligands that cannot fit within its lipid-binding pockets, as previously shown for the Pam(3)CysSerLys(4) (Pam(3)CSK(4)) lipopeptide. We first identified four critical residues in the upper region of the LT-IIb-B(5) pore. Corresponding point mutants (M69E, A70D, L73E, S74D) were defective in binding TLR2 or TLR1 and could not activate APCs, despite retaining full ganglioside-binding capacity. Point mutations in the TLR2/1 dimer interface, as determined in the crystallographic structure of the TLR2/1-Pam(3)CSK(4) complex, resulted in diminished activation by both Pam(3)CSK(4) and LT-IIb-B(5). Docking analysis of the LT-IIb-B(5) interaction with this apparently predominant activation conformation of TLR2/1 revealed that LT-IIb-B(5) might primarily contact the convex surface of the TLR2 central domain. Although the TLR1/LT-IIb-B(5) interface is relatively smaller, the leucine-rich repeat motifs 9-12 in the central domain of TLR1 were found to be critical for cooperative TLR2-induced cell activation by LT-IIb-B(5). Moreover, the putative LT-IIb-B(5) binding site overlaps partially with that of Pam(3)CSK(4); consistent with this, Pam(3)CSK(4) suppressed TLR2 binding of LT-IIb-B(5), albeit not as potently as self-competitive inhibition. We identified the upper pore region of LT-IIb-B(5) as a TLR2/1 interactive domain, which contacts the heterodimeric receptor at a site that is distinct from, although it overlaps with, that of Pam(3)CSK(4).
Collapse
Affiliation(s)
- Shuang Liang
- Center for Oral Health and Systemic Disease, University of Louisville Health Sciences Center, Louisville, KY 40292, USA
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Xaplanteri P, Lagoumintzis G, Dimitracopoulos G, Paliogianni F. Synergistic regulation of Pseudomonas aeruginosa-induced cytokine production in human monocytes by mannose receptor and TLR2. Eur J Immunol 2009; 39:730-40. [PMID: 19197942 DOI: 10.1002/eji.200838872] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The immune response to pathogen is regulated by a combination of specific PRR, which are involved in pathogen recognition. Pseudomonas aeruginosa, a bacterium that causes life-threatening disease in immuno-compromised host, is recognized by distinct members of the TLR family. We have previously shown that viable P. aeruginosa bacteria are recognized by human monocytes mainly through TLR2. Using ligand-specific blocking antibodies, we herein show that the mannose receptor (MR), a phagocytic receptor for unopsonized P. aeruginosa bacteria, contributes equally to TLR2 in proinflammatory cytokine production by human monocytes in response to P. aeruginosa infection. Synergy of both receptors totally controls the immune response. Viable P. aeruginosa bacteria activate NF-kappaB and MAPK pathways and enhance TLR2-mediated signaling in MR-transfected human embryonic kidney 293 cells. Moreover, MR follows the same kinetics and colocalizes with TLR2 in the endosome during in vivo infection of human macrophages with P. aeruginosa. The studies provide the first demonstration of a significant role for MR, synergistic with TLR2, in activating a proinflammatory response to P. aeruginosa infection.
Collapse
Affiliation(s)
- Panagiota Xaplanteri
- Department of Microbiology, School of Medicine, University of Patras, Patras, Greece
| | | | | | | |
Collapse
|
34
|
Epelman S, Berenger B, Stack D, Neely GG, Ma LL, Mody CH. Microbial Products Activate Monocytic Cells through Detergent-Resistant Membrane Microdomains. Am J Respir Cell Mol Biol 2008; 39:657-65. [DOI: 10.1165/rcmb.2007-0390oc] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
35
|
Randhawa AK, Hawn TR. Toll-like receptors: their roles in bacterial recognition and respiratory infections. Expert Rev Anti Infect Ther 2008; 6:479-95. [PMID: 18662115 DOI: 10.1586/14787210.6.4.479] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Although respiratory infections cause significant morbidity and mortality throughout the world, the immunologic factors that mediate host susceptibility to these infections remain poorly understood. The lung contains a vast surface at the host-environment interface and acts as a crucial barrier to invading pathogens. The lung is equipped with specialized epithelial and hematopoietic cells, which express pattern recognition receptors that act as both sentinels and mediators of pulmonary innate immunity. Toll-like receptors (TLRs) mediate a particularly critical role in pathogen recognition and subsequent initiation of the host immune response. In this review, we will summarize current knowledge of TLRs and their bacterial ligands and explore their role in respiratory infections. Moreover, we will highlight recent advances in the role of TLRs in pulmonary infections from a human immunogenetics perspective.
Collapse
Affiliation(s)
- April Kaur Randhawa
- Department of Medicine/Division of Allergy & Infections Diseases, University of Washington School of Medicine, 1959 NE Pacific Street, Seattle, WA 98195, USA.
| | | |
Collapse
|
36
|
Blohmke CJ, Victor RE, Hirschfeld AF, Elias IM, Hancock DG, Lane CR, Davidson AGF, Wilcox PG, Smith KD, Overhage J, Hancock REW, Turvey SE. Innate immunity mediated by TLR5 as a novel antiinflammatory target for cystic fibrosis lung disease. THE JOURNAL OF IMMUNOLOGY 2008; 180:7764-73. [PMID: 18490781 DOI: 10.4049/jimmunol.180.11.7764] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Novel therapies to target lung inflammation are predicted to improve the lives of people with cystic fibrosis (CF) but specific antiinflammatory targets have not been identified. The goal of this study was to establish whether TLR5 signaling is the key molecular pathway mediating lung inflammation in CF, and to determine whether strategies to inhibit TLR5 can reduce the damaging inflammatory response. The innate immune responses were analyzed in both airway epithelial cells and primary PBMCs from CF patients and matched controls. Additionally, 151 clinical isolates of Pseudomonas aeruginosa from CF patients were assessed for motility and capacity to activate TLR5. Blood and airway cells from CF patients produced significantly more proinflammatory cytokine than did control cells following exposure to the CF pathogens P. aeruginosa and Burkholderia cepacia complex (p < 0.001). Stimulation with pure TLR ligands demonstrated that TLR signaling appears to mediate the excessive cytokine production occurring in CF. Using complementary approaches involving both neutralizing Ab targeting TLR5 and flagellin-deficient bacteria, we established that inhibition of TLR5 abolished the damaging inflammatory response generated by CF airway cells following exposure to P. aeruginosa (p < 0.01). The potential therapeutic value of TLR5 inhibition was further supported by our demonstration that 75% of clinical isolates of P. aeruginosa retained TLR5 activating capacity during chronic CF lung infection. These studies identify the innate immune receptor TLR5 as a novel antiinflammatory target for reducing damaging lung inflammation in CF.
Collapse
Affiliation(s)
- Christoph J Blohmke
- Department of Paediatrics, British Columbia Children's Hospital and Child and Family Research Institute, University of Brtish Columbia, Vancouver, Britsh Columbia, Canada
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Lagoumintzis G, Xaplanteri P, Dimitracopoulos G, Paliogianni F. TNF-alpha Induction byPseudomonas aeruginosaLipopolysaccharide or Slime-glycolipoprotein in Human Monocytes is Regulated at the Level of Mitogen-activated Protein Kinase Activity: A Distinct Role of Toll-like Receptor 2 and 4. Scand J Immunol 2008; 67:193-203. [DOI: 10.1111/j.1365-3083.2007.02053.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
|
38
|
Mukherjee G, Biswas A, Banerjee KK, Biswas T. Vibrio cholerae hemolysin is apoptogenic to peritoneal B-1a cells but its oligomer shepherd the cells for IgA response. Mol Immunol 2008; 45:266-70. [PMID: 17570527 DOI: 10.1016/j.molimm.2007.04.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2007] [Revised: 04/20/2007] [Accepted: 04/20/2007] [Indexed: 11/16/2022]
Abstract
Vibrio cholerae hemolysin (HlyA) can exist as a monomer with hemolytic activity and an oligomer that agglutinates erythrocytes. Biochemical differences accompanying the change in state of aggregation led us to weigh possible differences between the two forms from mucosal immunoregulation perspective. HlyA oligomer-treated murine B-1a cells up-regulated TLR2 and involved the signaling molecules MyD88, TRAF6 and NF-kappaB. The cells subsequently expressed IgM and IgA. HlyA monomer treatment although resulted in TLR2 up-regulation, could not induce these effects. Apoptosis was detected in majority of the monomer-treated cells that involved caspase-9 and caspase-3. This study shows for the first time that two forms of the same protein could drive the host immune cell to two different outcomes, one of death and the other towards activation.
Collapse
Affiliation(s)
- Gayatri Mukherjee
- Division of Immunology and Vaccine Development, National Institute of Cholera and Enteric Diseases, P-33, C.I.T. Road, Scheme XM, Kolkata-700 010, West Bengal, India
| | | | | | | |
Collapse
|
39
|
Galle M, Schotte P, Haegman M, Wullaert A, Yang HJ, Jin S, Beyaert R. The Pseudomonas aeruginosa Type III secretion system plays a dual role in the regulation of caspase-1 mediated IL-1beta maturation. J Cell Mol Med 2007; 12:1767-76. [PMID: 18081695 PMCID: PMC3918092 DOI: 10.1111/j.1582-4934.2007.00190.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic bacterial pathogen that forms a serious problem for immunocompromised patients and also the leading cause of mortality in cystic fibrosis. The overall importance of a functional Type III secretion system (T3SS) in P. aeru inosa virulence has been well established, but the underlying mechanisms are still unclear. Using in vitro infected macrophages as w as a murine model of acute lung infection, we show that the Caspase-1 mediated maturation and secretion of IL-1β needs a translocation competent T3SS and Flagellin, but not the Type III effector proteins ExoS, ExoT and ExoY. However, ExoS was found to negative regulate the P. aeruginosa induced IL-1β maturation by a mechanism that is dependent on its ADP ribosyltransferase activity. Moreov ExoS deficiency also switched the mode of macrophage death from apoptosis to pro-inflammatory pyroptosis. Altogether, these da demonstrate a dual role for the P. aeruginosa T3SS in the regulation of Caspase-1 mediated IL-1β production and provide new insigh into the mechanisms of immune evasion by this pathogen.
Collapse
Affiliation(s)
- M Galle
- Department of Molecular Biology, Ghent University, Ghent, Belgium
| | | | | | | | | | | | | |
Collapse
|
40
|
Abstract
Type III secretion systems (T3SSs) are complex bacterial structures that provide gram-negative pathogens with a unique virulence mechanism enabling them to inject bacterial effector proteins directly into the host cell cytoplasm, bypassing the extracellular milieu. Although the effector proteins vary among different T3SS pathogens, common pathogenic mechanisms emerge, including interference with the host cell cytoskeleton to promote attachment and invasion, interference with cellular trafficking processes, cytotoxicity and barrier dysfunction, and immune system subversion. The activity of the T3SSs correlates closely with infection progression and outcome, both in animal models and in human infection. Therefore, to facilitate patient care and improve outcomes, it is important to understand the T3SS-mediated virulence processes and to target T3SSs in therapeutic and prophylactic development efforts.
Collapse
|
41
|
Affiliation(s)
- Denis F Kinane
- Center for Oral Health and Systemic Disease, University of Louisville School of Dentistry, Louisville, KY, USA
| | | | | | | | | |
Collapse
|
42
|
Sajjan US, Hershenson MB, Forstner JF, LiPuma JJ. Burkholderia cenocepacia ET12 strain activates TNFR1 signalling in cystic fibrosis airway epithelial cells. Cell Microbiol 2007; 10:188-201. [PMID: 17697131 PMCID: PMC3226749 DOI: 10.1111/j.1462-5822.2007.01029.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Burkholderia cenocepacia is an important pulmonary pathogen in individuals with cystic fibrosis (CF). Infection is often associated with severe pulmonary inflammation, and some patients develop a fatal necrotizing pneumonia and sepsis ('cepacia syndrome'). The mechanisms by which this species causes severe pulmonary inflammation are poorly understood. Here, we demonstrate that B. cenocepacia BC7, a potentially virulent representative of the epidemic ET12 lineage, binds to tumour necrosis factor receptor 1 (TNFR1) and activates TNFR1-related signalling pathway similar to TNF-alpha, a natural ligand for TNFR1. This interaction participates in stimulating a robust IL-8 production from CF airway epithelial cells. In contrast, BC45, a less virulent ET12 representative, and ATCC 25416, an environmental B. cepacia strain, do not bind to TNFR1 and stimulate only minimal IL-8 production from CF cells. Further, TNFR1 expression is increased in CF airway epithelial cells compared with non-CF cells. We also show that B. cenocepacia ET12 strain colocaizes with TNFR1 in vitro and in the lungs of CF patients who died due to infection with B. cenocepacia, ET12 strain. Together, these results suggest that interaction of B. cenocepacia, ET12 strain with TNFR1 may contribute to robust inflammatory responses elicited by this organism.
Collapse
Affiliation(s)
- Umadevi S Sajjan
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA.
| | | | | | | |
Collapse
|
43
|
Willcox MDP. Pseudomonas aeruginosa infection and inflammation during contact lens wear: a review. Optom Vis Sci 2007; 84:273-8. [PMID: 17435510 DOI: 10.1097/opx.0b013e3180439c3e] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Infection and inflammation during contact lens wear is often associated with microbial contamination of lenses. Several different types of microbes that colonize lenses can lead to infection and inflammation, but the most common cause of infection (microbial keratitis; MK) remains the Gram-negative bacterium Pseudomonas aeruginosa. P. aeruginosa has a battery of cell-associated and extracellular virulence factors it can use to initiate and maintain infection. Its ability to produce proteases, to either invade or kill corneal cells, and to coordinate expression of virulence factors via quorum-sensing have been shown to be important during MK. Another important factor that contributes to the destruction of the cornea during MK is excessive activation of the host defense system. P. aeruginosa can activate several pathways of the immune system during MK, and activation often involves receptors on the corneal epithelial cells called toll-like receptors (TLRs). These TLRs recognize e.g., lipopolysaccharide or flagella from P. aeruginosa and activate the epithelial cells to produce inflammatory mediators such as cytokines and chemokines. These cytokines or chemokines recruit white blood cells, predominantly polymorphonuclear leukocytes, to the infection in order that they can phagocytose and kill the P. aeruginosa. However, continued recruitment and presence of these polymorphonuclear neutrophils and other white blood cells in the corneal tissue leads to destruction of corneal cells and tissue components. This can ultimately lead to scarring and vision loss.
Collapse
Affiliation(s)
- Mark D P Willcox
- Institute for Eye Research, Vision CRC and School of Optometry and Vision Science, University of New South Wales, Australia.
| |
Collapse
|
44
|
Power MR, Li B, Yamamoto M, Akira S, Lin TJ. A role of Toll-IL-1 receptor domain-containing adaptor-inducing IFN-beta in the host response to Pseudomonas aeruginosa lung infection in mice. THE JOURNAL OF IMMUNOLOGY 2007; 178:3170-6. [PMID: 17312165 DOI: 10.4049/jimmunol.178.5.3170] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Toll-IL-1R domain-containing adaptor-inducing IFN-beta (TRIF) is an adaptor molecule that mediates a distinct TLR signaling pathway. Roles of TRIF in the host defense have been primarily associated with virus infections owing to the induction of IFN-alphabeta. In this study, we investigated a role of TRIF in Pseudomonas aeruginosa infection. In vitro, TRIF-deficient mouse alveolar and peritoneal macrophages showed a complete inhibition of RANTES (CCL5) production, severely impaired TNF and KC (CXCL1) production, and reduced NF-kappaB activation in response to P. aeruginosa stimulation. In vivo, TRIF-deficient mice showed a complete inhibition of RANTES production, a severely impaired TNF and KC production, and an efficient MIP-2 and IL-1beta production in the lung following P. aeruginosa infection. This outcome was associated with a delayed recruitment of neutrophils into the airways. These results suggest that TRIF mediates a distinct cytokine/chemokine profile in response to P. aeruginosa infection. P. aeruginosa-induced RANTES production is completely dependent on TRIF pathway in mice. Importantly, TRIF deficiency leads to impaired clearance of P. aeruginosa from the lung during the initial 24-48 h of infection. Thus, TRIF represents a novel mechanism involved in the development of host response to P. aeruginosa infection.
Collapse
MESH Headings
- Adaptor Proteins, Vesicular Transport/deficiency
- Adaptor Proteins, Vesicular Transport/immunology
- Animals
- Cells, Cultured
- Cytokines/immunology
- Interferon-beta/immunology
- Macrophages, Alveolar/immunology
- Macrophages, Alveolar/microbiology
- Macrophages, Alveolar/pathology
- Macrophages, Peritoneal/immunology
- Macrophages, Peritoneal/microbiology
- Macrophages, Peritoneal/pathology
- Mice
- NF-kappa B/immunology
- Pneumonia, Bacterial/genetics
- Pneumonia, Bacterial/immunology
- Pneumonia, Bacterial/microbiology
- Pneumonia, Bacterial/pathology
- Pseudomonas Infections/genetics
- Pseudomonas Infections/immunology
- Pseudomonas Infections/pathology
- Pseudomonas aeruginosa/immunology
- Time Factors
Collapse
Affiliation(s)
- Melanie R Power
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | | | | | | | | |
Collapse
|
45
|
Abstract
Toll-like receptors (TLR), a family of evolutionarily conserved pathogen recognition receptors, play pivotal role as primary sensors of invading pathogens. TLR identify molecular motifs of infectious agents (pathogen associated molecular patterns) and elicit an effective defensive response against them. Mammalian TLR derive their name from the Drosophila Toll protein, with which they share sequence similarity. So far, expression of 10 TLR is known in humans. The adaptor proteins, myeloid differentiation factor 88 and Toll IL-1 receptor (TIR) domain containing adaptor inducing IFN-beta (TRIF) are the key players in the TLR signalling cascade leading to the activation of nuclear factor (NF)-kappaB and interferon regulatory factor-3, respectively. Targeted manipulation of the TLR signalling pathway has immense therapeutic potential and may eventually prove to be a boon in the development of innovative treatments for diverse disease conditions. There is accumulating evidence that TLR agonists have tremendous potential as novel therapeutic targets. In this review, we have discussed the immunobiology of TLR and emphasize significant advances made within the ever-expanding field of TLR that provide intriguing insights efficacious in unravelling the complexities associated with TLR.
Collapse
Affiliation(s)
- Saumya Pandey
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68178, USA
| | | |
Collapse
|
46
|
Skerrett SJ, Wilson CB, Liggitt HD, Hajjar AM. Redundant Toll-like receptor signaling in the pulmonary host response to Pseudomonas aeruginosa. Am J Physiol Lung Cell Mol Physiol 2006; 292:L312-22. [PMID: 16936244 DOI: 10.1152/ajplung.00250.2006] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Activation of pulmonary defenses against Pseudomonas aeruginosa requires myeloid differentiation factor 88 (MyD88), an adaptor for Toll-like receptor (TLR) signaling. To determine which TLRs mediate recognition of P. aeruginosa, we measured cytokine responses of bone marrow cells from wild-type mice and mice lacking TLR2 (TLR2(-/-)), TLR4 (TLR4(-/-)), TLR2 and TLR4 (TLR2/4(-/-)), or MyD88 (MyD88(-/-)) to wild-type P. aeruginosa and to fliC P. aeruginosa, which lacks the TLR5 ligand flagellin. Mice also were challenged with aerosolized bacteria to determine cytokine responses, lung inflammation, and bacterial clearance. TNF induction required MyD88 and was absent in TLR2/4(-/-) cells in response to fliC but not wild-type P. aeruginosa, whereas TLR2(-/-) cells exhibited augmented responses. In vivo, TLR4(-/-) mice responded to wild-type P. aeruginosa with reduced cytokine production and inflammation, but intact bacterial clearance, while TLR2(-/-) mice had partially impaired cytokine responses and delayed bacterial killing despite normal inflammation. When challenged with fliC, MyD88(-/-) mice failed to mount early cytokine and inflammatory responses or control bacterial replication, resulting in necrotizing lung injury and lethal disseminated infection. TLR4(-/-) and TLR2/4(-/-) mice responded to fliC infection with severely limited inflammatory and cytokine responses but intact bacterial clearance. TLR2(-/-) mice had partially reduced cytokine responses but augmented inflammation and preserved bacterial killing. These data indicate that TLR4- and flagellin-induced signals mediate most of the acute inflammatory response to Pseudomonas and that TLR2 has a counterregulatory role. However, MyD88-dependent pathways, in addition to those downstream of TLR2, TLR4, and TLR5, are required for pulmonary defense against P. aeruginosa.
Collapse
Affiliation(s)
- Shawn J Skerrett
- Division of Pulmonary and Critical Care Medicine, Harborview Medical Center, 325 Ninth Avenue, Box 359640, Seattle, WA 98104, USA.
| | | | | | | |
Collapse
|
47
|
Pecora ND, Gehring AJ, Canaday DH, Boom WH, Harding CV. Mycobacterium tuberculosis LprA is a lipoprotein agonist of TLR2 that regulates innate immunity and APC function. THE JOURNAL OF IMMUNOLOGY 2006; 177:422-9. [PMID: 16785538 DOI: 10.4049/jimmunol.177.1.422] [Citation(s) in RCA: 160] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
TLR2 recognizes components of Mycobacterium tuberculosis (Mtb) and initiates responses by APCs that influence both innate and adaptive immunity. Mtb lipoproteins are an important class of TLR2 ligand, but only two, LpqH and LprG, have been characterized to date. In this study, we characterize a third Mtb lipoprotein, LprA, and determine its effects on host macrophages and dendritic cells. LprA is a cell wall-associated lipoprotein with no homologs outside the slow-growing mycobacteria. Using Mycobacterium smegmatis as an expression host, we purified 6x His-tagged LprA both with and without its acyl modifications. Acylated LprA had agonist activity for both human and murine TLR2 and induced expression of TNF-alpha, IL-10, and IL-12. LprA also induced dendritic cell maturation as shown by increased expression of CD40, CD80, and class II MHC (MHC-II). In macrophages, prolonged (24 h) incubation with LprA decreased IFN-gamma-induced MHC-II Ag processing and presentation, consistent with an observed decrease in MHC-II expression (macrophage viability was not affected and apoptosis was not induced by LprA). Reduced MHC-II Ag presentation may represent a negative feedback mechanism for control of inflammation that may be subverted by Mtb for immune evasion. Thus, Mtb LprA is a TLR2 agonist that induces cytokine responses and regulates APC function.
Collapse
Affiliation(s)
- Nicole D Pecora
- Department of Pathology, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106-7288, USA
| | | | | | | | | |
Collapse
|
48
|
Hippenstiel S, Opitz B, Schmeck B, Suttorp N. Lung epithelium as a sentinel and effector system in pneumonia--molecular mechanisms of pathogen recognition and signal transduction. Respir Res 2006; 7:97. [PMID: 16827942 PMCID: PMC1533821 DOI: 10.1186/1465-9921-7-97] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2006] [Accepted: 07/08/2006] [Indexed: 12/22/2022] Open
Abstract
Pneumonia, a common disease caused by a great diversity of infectious agents is responsible for enormous morbidity and mortality worldwide. The bronchial and lung epithelium comprises a large surface between host and environment and is attacked as a primary target during lung infection. Besides acting as a mechanical barrier, recent evidence suggests that the lung epithelium functions as an important sentinel system against pathogens. Equipped with transmembranous and cytosolic pathogen-sensing pattern recognition receptors the epithelium detects invading pathogens. A complex signalling results in epithelial cell activation, which essentially participates in initiation and orchestration of the subsequent innate and adaptive immune response. In this review we summarize recent progress in research focussing on molecular mechanisms of pathogen detection, host cell signal transduction, and subsequent activation of lung epithelial cells by pathogens and their virulence factors and point to open questions. The analysis of lung epithelial function in the host response in pneumonia may pave the way to the development of innovative highly needed therapeutics in pneumonia in addition to antibiotics.
Collapse
Affiliation(s)
- Stefan Hippenstiel
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité – Universitätsmedizin Berlin, 13353 Berlin, Germany
| | - Bastian Opitz
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité – Universitätsmedizin Berlin, 13353 Berlin, Germany
| | - Bernd Schmeck
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité – Universitätsmedizin Berlin, 13353 Berlin, Germany
| | - Norbert Suttorp
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité – Universitätsmedizin Berlin, 13353 Berlin, Germany
| |
Collapse
|
49
|
Delgado MA, Poschet JF, Deretic V. Nonclassical pathway of Pseudomonas aeruginosa DNA-induced interleukin-8 secretion in cystic fibrosis airway epithelial cells. Infect Immun 2006; 74:2975-84. [PMID: 16622236 PMCID: PMC1459729 DOI: 10.1128/iai.74.5.2975-2984.2006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Pseudomonas aeruginosa is a critical colonizer of the respiratory tract in cystic fibrosis. The chronic infections with this microorganism contribute to excessive inflammation and progressive lung damage in cystic fibrosis patients. The full repertoire of Pseudomonas products that promote inflammation in the cystic fibrosis lung is not known. Here we show that P. aeruginosa DNA released from the bacterium, but not human DNA from epithelial cells or Escherichia coli DNA, displays proinflammatory properties and induces human respiratory epithelial cells to secrete interleukin-8 (IL-8), a key chemokine causing excessive neutrophil infiltration in the cystic fibrosis lung. IL-8 secretion was not due to an increase in NF-kappaB- or activator protein-1-dependent IL-8 promoter transcription, but instead depended on p38 and Erk mitogen-activated protein kinases. No secretion of IL-8 was observed using conventional Toll-like receptor 9 ligands (CpG oligonucleotides), although it could be demonstrated that parts of the Toll-like receptor 9-signaling pathway were functional, since class B and C CpG oligonucleotide ligands stimulated production of RANTES chemokine. The IL-8 secretion in response to P. aeruginosa DNA was decreased by treatments that inhibit acidification of intracellular organelles, using chloroquine, a pH-neutralizing compound, or bafilomycin A1, an inhibitor of vacuolar H+-ATPase. These data indicate that DNA released from P. aeruginosa during chronic infections may significantly contribute to the proinflammatory processes in cystic fibrosis. Our findings also show that treatments with drugs diminishing organellar acidification may reduce the inflammatory response in cystic fibrosis.
Collapse
Affiliation(s)
- Mónica A Delgado
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, 915 Camino de Salud NE, Albuquerque, NM 87131, USA
| | | | | |
Collapse
|
50
|
Abstract
Major allergens may have special aerobiological properties and allergenic structures. It would also be instructive to consider the properties of nonallergens and nonallergenic responses. In some cases, nonallergenic responses appear to result from a lack of antigenicity and in others from regulation. Proteolytic activity has been proposed as an adjuvant for allergenicity, but lipid binding is far more common and is found for more than 50% of the major allergens. Such structures can enhance allergenicity via Toll-like receptor (TLR) or CD1 pathways. TLR signaling can enhance both Th1 and Th2 responses and be induced by peptides as well as nonproteinaceous ligands.
Collapse
Affiliation(s)
- Wayne R Thomas
- Centre for Child Health Research, Telethon Institute for Child Health Research, The University of Western Australia, PO Box 855, West Perth, WA 6872, Australia.
| | | | | |
Collapse
|