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Martínez-Gómez LE, Martinez-Armenta C, Medina-Luna D, Ordoñez-Sánchez ML, Tusie-Luna T, Ortega-Peña S, Herrera-López B, Suarez-Ahedo C, Jimenez-Gutierrez GE, Hidalgo-Bravo A, Vázquez-Cárdenas P, Vidal-Vázquez RP, Ramírez-Hinojosa JP, Martinez Matsumoto PM, Vargas-Alarcón G, Posadas-Sánchez R, Fragoso JM, Martínez-Ruiz FDJ, Zayago-Angeles DM, Mata-Miranda MM, Vázquez-Zapién GJ, Martínez-Cuazitl A, Andrade-Alvarado J, Granados J, Ramos-Tavera L, Camacho-Rea MDC, Segura-Kato Y, Rodríguez-Pérez JM, Coronado-Zarco R, Franco-Cendejas R, López-Jácome LE, Magaña JJ, Vela-Amieva M, Pineda C, Martínez-Nava GA, López-Reyes A. Implication of myddosome complex genetic variants in outcome severity of COVID-19 patients. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2023; 56:939-950. [PMID: 37365052 PMCID: PMC10273757 DOI: 10.1016/j.jmii.2023.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 03/31/2023] [Accepted: 06/10/2023] [Indexed: 06/28/2023]
Abstract
BACKGROUND/PURPOSE(S) During a viral infection, the immune response is mediated by the toll-like receptors and myeloid differentiation Factor 88 (MyD88) that play an important role sensing infections such as SARS-CoV-2 which has claimed the lives of more than 6.8 million people around the world. METHODS We carried out a cross-sectional with a population of 618 SARS-CoV-2-positive unvaccinated subjects and further classified based on severity: 22% were mild, 34% were severe, 26% were critical, and 18% were deceased. Toll Like Receptor 7 (TLR7) single-nucleotide polymorphisms (rs3853839, rs179008, rs179009, and rs2302267) and MyD88 (rs7744) were genotyped using TaqMan OpenArray. The association of polymorphisms with disease outcomes was performed by logistic regression analysis adjusted by covariates. RESULTS A significant association of rs3853839 and rs7744 of the TLR7 and MyD88 genes, respectively, was found with COVID-19 severity. The G/G genotype of the rs3853839 TLR7 was associated with the critical outcome showing an Odd Ratio = 1.98 (95% IC = 1.04-3.77). The results highlighted an association of the G allele of MyD88 gene with severe, critical and deceased outcomes. Furthermore, in the dominant model (AG + GG vs. AA), we observed an Odd Ratio = 1.70 (95% CI = 1.02-2.86) with severe, Odd Ratio = 1.82 (95% CI = 1.04-3.21) with critical, and Odd Ratio = 2.44 (95% CI = 1.21-4.9) with deceased outcomes. CONCLUSION To our knowledge this work represents an innovative report that highlights the significant association of TLR7 and MyD88 gene polymorphisms with COVID-19 outcomes and the possible implication of the MyD88 variant with D-dimer and IFN-α concentrations.
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Affiliation(s)
- Laura E Martínez-Gómez
- Laboratorio de Gerociencias, Dirección General, Medicina de Rehabilitación, Laboratorio de Infectología, Departamento de Reconstrucción Articular, Laboratorio de Medicina Genómica, Laboratorio Facilitador. Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Secretaría de Salud, Ciudad de México, Mexico.
| | - Carlos Martinez-Armenta
- Graduate Program in Experimental Biology, Dirección de Ciencias Biológicas y de la Salud (DCBS), Universidad Autónoma Metropolitana Iztapalapa, Ciudad de México, Mexico.
| | - Daniel Medina-Luna
- Microbiology & Immunology Department, Dalhousie University, Halifax, B3H4R2, Nova Scotia, Canada.
| | - María Luisa Ordoñez-Sánchez
- Unidad de Biología Molecular y Medicina Genómica, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico.
| | - Tere Tusie-Luna
- Unidad de Biología Molecular y Medicina Genómica, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico; Instituto de Investigaciones Biomédicas Universidad Nacional Autónoma de México, Mexico City, Mexico.
| | - Silvestre Ortega-Peña
- Laboratorio de Gerociencias, Dirección General, Medicina de Rehabilitación, Laboratorio de Infectología, Departamento de Reconstrucción Articular, Laboratorio de Medicina Genómica, Laboratorio Facilitador. Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Secretaría de Salud, Ciudad de México, Mexico.
| | - Brígida Herrera-López
- Laboratorio de Gerociencias, Dirección General, Medicina de Rehabilitación, Laboratorio de Infectología, Departamento de Reconstrucción Articular, Laboratorio de Medicina Genómica, Laboratorio Facilitador. Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Secretaría de Salud, Ciudad de México, Mexico.
| | - Carlos Suarez-Ahedo
- Laboratorio de Gerociencias, Dirección General, Medicina de Rehabilitación, Laboratorio de Infectología, Departamento de Reconstrucción Articular, Laboratorio de Medicina Genómica, Laboratorio Facilitador. Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Secretaría de Salud, Ciudad de México, Mexico.
| | - Guadalupe Elizabeth Jimenez-Gutierrez
- Laboratorio de Gerociencias, Dirección General, Medicina de Rehabilitación, Laboratorio de Infectología, Departamento de Reconstrucción Articular, Laboratorio de Medicina Genómica, Laboratorio Facilitador. Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Secretaría de Salud, Ciudad de México, Mexico.
| | - Alberto Hidalgo-Bravo
- Laboratorio de Gerociencias, Dirección General, Medicina de Rehabilitación, Laboratorio de Infectología, Departamento de Reconstrucción Articular, Laboratorio de Medicina Genómica, Laboratorio Facilitador. Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Secretaría de Salud, Ciudad de México, Mexico.
| | - Paola Vázquez-Cárdenas
- Centro de Innovación Médica Aplicada, Hospital General Dr. Manuel Gea González, Ciudad de México, Mexico.
| | - Rosa P Vidal-Vázquez
- Centro de Innovación Médica Aplicada, Hospital General Dr. Manuel Gea González, Ciudad de México, Mexico.
| | - Juan P Ramírez-Hinojosa
- Centro de Innovación Médica Aplicada, Hospital General Dr. Manuel Gea González, Ciudad de México, Mexico.
| | | | - Gilberto Vargas-Alarcón
- Departamento de Biología Molecular y Endocrinología, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de México, Mexico.
| | - Rosalinda Posadas-Sánchez
- Departamento de Biología Molecular y Endocrinología, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de México, Mexico.
| | - José-Manuel Fragoso
- Departamento de Biología Molecular y Endocrinología, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de México, Mexico.
| | | | | | - Mónica Maribel Mata-Miranda
- Laboratorio de Biología Celular y Tisular, Laboratorio de Embriología, Escuela Médico Militar, Universidad del Ejército y Fuerza Aérea, Ciudad de México, Mexico.
| | - Gustavo Jesús Vázquez-Zapién
- Laboratorio de Biología Celular y Tisular, Laboratorio de Embriología, Escuela Médico Militar, Universidad del Ejército y Fuerza Aérea, Ciudad de México, Mexico.
| | - Adriana Martínez-Cuazitl
- Laboratorio de Biología Celular y Tisular, Laboratorio de Embriología, Escuela Médico Militar, Universidad del Ejército y Fuerza Aérea, Ciudad de México, Mexico.
| | - Javier Andrade-Alvarado
- Servicio de Cirugía General, Hospital Central Norte Petróleos Mexicanos (PEMEX), Estado de México, Mexico.
| | - Julio Granados
- Departamento de Inmunogenética, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Secretaría de Salud, Mexico City, Mexico.
| | - Luis Ramos-Tavera
- Departamento de Inmunogenética, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Secretaría de Salud, Mexico City, Mexico.
| | - María Del Carmen Camacho-Rea
- Departamento de Nutrición Animal, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Secretaría de Salud, Mexico City, Mexico
| | - Yayoi Segura-Kato
- Unidad de Biología Molecular y Medicina Genómica, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico.
| | - José Manuel Rodríguez-Pérez
- Departamento de Biología Molecular y Endocrinología, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de México, Mexico.
| | - Roberto Coronado-Zarco
- Laboratorio de Gerociencias, Dirección General, Medicina de Rehabilitación, Laboratorio de Infectología, Departamento de Reconstrucción Articular, Laboratorio de Medicina Genómica, Laboratorio Facilitador. Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Secretaría de Salud, Ciudad de México, Mexico.
| | - Rafael Franco-Cendejas
- Laboratorio de Gerociencias, Dirección General, Medicina de Rehabilitación, Laboratorio de Infectología, Departamento de Reconstrucción Articular, Laboratorio de Medicina Genómica, Laboratorio Facilitador. Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Secretaría de Salud, Ciudad de México, Mexico.
| | - Luis Esau López-Jácome
- Laboratorio de Gerociencias, Dirección General, Medicina de Rehabilitación, Laboratorio de Infectología, Departamento de Reconstrucción Articular, Laboratorio de Medicina Genómica, Laboratorio Facilitador. Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Secretaría de Salud, Ciudad de México, Mexico.
| | - Jonathan J Magaña
- Laboratorio de Gerociencias, Dirección General, Medicina de Rehabilitación, Laboratorio de Infectología, Departamento de Reconstrucción Articular, Laboratorio de Medicina Genómica, Laboratorio Facilitador. Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Secretaría de Salud, Ciudad de México, Mexico.
| | - Marcela Vela-Amieva
- Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaria de Salud, Ciudad de México, Mexico.
| | - Carlos Pineda
- Laboratorio de Gerociencias, Dirección General, Medicina de Rehabilitación, Laboratorio de Infectología, Departamento de Reconstrucción Articular, Laboratorio de Medicina Genómica, Laboratorio Facilitador. Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Secretaría de Salud, Ciudad de México, Mexico.
| | - Gabriela Angélica Martínez-Nava
- Laboratorio de Gerociencias, Dirección General, Medicina de Rehabilitación, Laboratorio de Infectología, Departamento de Reconstrucción Articular, Laboratorio de Medicina Genómica, Laboratorio Facilitador. Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Secretaría de Salud, Ciudad de México, Mexico.
| | - Alberto López-Reyes
- Laboratorio de Gerociencias, Dirección General, Medicina de Rehabilitación, Laboratorio de Infectología, Departamento de Reconstrucción Articular, Laboratorio de Medicina Genómica, Laboratorio Facilitador. Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Secretaría de Salud, Ciudad de México, Mexico.
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Chen P, Zhou Y, Li X, Yang J, Zheng Z, Zou Y, Li X, Liao J, Dai J, Xu Y, Yin L, Chen G, Gu J, Ouyang Q, Cho WJ, Tang Q, Liang G. Design, Synthesis, and Bioevaluation of Novel MyD88 Inhibitor c17 against Acute Lung Injury Derived from the Virtual Screen. J Med Chem 2023; 66:6938-6958. [PMID: 37130331 DOI: 10.1021/acs.jmedchem.3c00359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Myeloid differentiation primary response protein 88 (MyD88) is crucial to immune cascades mediated by Toll-like receptors (TLRs) and interleukin-1 receptors (IL-1Rs). MyD88 dysregulation has been linked to a wide variety of inflammatory diseases, making it a promising new target for anti-inflammatory and cancer therapy development. In this study, 46 compounds were designed and synthesized inspired by virtual screen hit. The anti-inflammatory activity of designed compounds was evaluated biologically, and c17 was discovered to have a high binding affinity with MyD88. It inhibited the interaction of TLR4 and MyD88 and suppressed the NF-κB pathway. In addition, c17 treatment led to the accumulation in the lungs of rats and attenuated LPS-induced ALI mice model. Furthermore, c17 showed negligible toxicity in vivo. Together, these findings suggest that c17 may serve as a potential therapeutical method for the treatment of ALI and as a lead structure for the continued development of MyD88 inhibitors.
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Affiliation(s)
- Pan Chen
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
- School of Pharmaceutical Sciences, Hangzhou Medical College, Hangzhou 310053, China
- College of Pharmacy, Chonnam National University, Gwangju 61186, Korea
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, China
| | - Ying Zhou
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, China
| | - Xiaobo Li
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, China
| | - Jun Yang
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, China
| | - Zhiwei Zheng
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
- College of Pharmacy, Chonnam National University, Gwangju 61186, Korea
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, China
| | - Yu Zou
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, China
| | - Xiang Li
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, China
| | - Jing Liao
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, China
| | - Jintian Dai
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, China
| | - Yuye Xu
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, China
| | - Lina Yin
- School of Pharmaceutical Sciences, Hangzhou Medical College, Hangzhou 310053, China
| | - Gaozhi Chen
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
| | - Jing Gu
- Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, Chongqing 400038, China
| | - Qin Ouyang
- Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, Chongqing 400038, China
| | - Won-Jea Cho
- College of Pharmacy, Chonnam National University, Gwangju 61186, Korea
| | - Qidong Tang
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, China
| | - Guang Liang
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
- School of Pharmaceutical Sciences, Hangzhou Medical College, Hangzhou 310053, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, China
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Strong toll-like receptor responses in cystic fibrosis patients are associated with higher lung function. J Cyst Fibros 2019; 19:608-613. [PMID: 31813753 DOI: 10.1016/j.jcf.2019.11.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 11/21/2019] [Accepted: 11/22/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Cystic fibrosis (CF) airways disease varies widely among patients with identical cystic fibrosis transmembrane conductance regulator (CFTR) genotypes. Robust airway inflammation is thought to be deleterious in CF; inter-individual variation in Toll-like receptor (TLR)-mediated innate immune inflammatory responses (TMIIR) might account for a portion of the phenotypic variation. We tested if TMIIR in people with CF are different than those of healthy controls, and whether higher TMIIR in people with CF are associated with reduced lung function. METHODS We cultured whole blood from clinically stable subjects with CF (n = 76) and healthy controls (n = 45) with TLR agonists, and measured cytokine production and expression of TLR-associated genes. We tested for differences in TLR-stimulated cytokine levels between subjects with CF and healthy subjects, and for associations between cytokine and gene expression levels with baseline lung function (forced expiratory volume in one second percent predicted (FEV1%)) and decline in FEV1% over time. RESULTS TMIIR in blood from subjects with CF were lower than in healthy controls. Expression of TLR regulators SARM1, TOLLIP, and AKT1 were downregulated in CF. In subjects with CF we found that lower TLR4-agonist-induced IL-8 was associated with lower FEV1% at enrollment (p<0.001) and with greater five year FEV1% decline (p<0.001). CONCLUSIONS TMIIR were lower in people with CF relative to healthy controls; however, unexpectedly, greater whole blood TMIIR were positively associated with lung function in people with CF. These findings suggest a complex interaction between inflammation and disease in people with CF.
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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: 62] [Impact Index Per Article: 12.4] [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.
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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.
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Macrophages, but not neutrophils, are critical for proliferation of Burkholderia cenocepacia and ensuing host-damaging inflammation. PLoS Pathog 2017. [PMID: 28651010 PMCID: PMC5501683 DOI: 10.1371/journal.ppat.1006437] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Bacteria of the Burkholderia cepacia complex (Bcc) can cause devastating pulmonary infections in cystic fibrosis (CF) patients, yet the precise mechanisms underlying inflammation, recurrent exacerbations and transition from chronic stages to acute infection and septicemia are not known. Bcc bacteria are generally believed to have a predominant extracellular biofilm life style in infected CF lungs, similar to Pseudomonas aeruginosa, but this has been challenged by clinical observations which show Bcc bacteria predominantly in macrophages. More recently, Bcc bacteria have emerged in nosocomial infections of patients hospitalized for reasons unrelated to CF. Research has abundantly shown that Bcc bacteria can survive and replicate in mammalian cells in vitro, yet the importance of an intracellular life style during infection in humans is unknown. Here we studied the contribution of innate immune cell types to fatal pro-inflammatory infection caused by B. cenocepacia using zebrafish larvae. In strong contrast to the usual protective role for macrophages against microbes, our results show that these phagocytes significantly worsen disease outcome. We provide new insight that macrophages are critical for multiplication of B. cenocepacia in the host and for development of a fatal, pro-inflammatory response that partially depends on Il1-signalling. In contrast, neutrophils did not significantly contribute to disease outcome. In subcutaneous infections that are dominated by neutrophil-driven phagocytosis, the absence of a functional NADPH oxidase complex resulted in a small but measurably higher increase in bacterial growth suggesting the oxidative burst helps limit bacterial multiplication; however, neutrophils were unable to clear the bacteria. We suggest that paradigm-changing approaches are needed for development of novel antimicrobials to efficiently disarm intracellular bacteria of this group of highly persistent, opportunistic pathogens.
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Immune Recognition of the Epidemic Cystic Fibrosis Pathogen Burkholderia dolosa. Infect Immun 2017; 85:IAI.00765-16. [PMID: 28348057 DOI: 10.1128/iai.00765-16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 03/20/2017] [Indexed: 12/31/2022] Open
Abstract
Burkholderia dolosa caused an outbreak in the cystic fibrosis (CF) clinic at Boston Children's Hospital from 1998 to 2005 and led to the infection of over 40 patients, many of whom died due to complications from infection by this organism. To assess whether B. dolosa significantly contributes to disease or is recognized by the host immune response, mice were infected with a sequenced outbreak B. dolosa strain, AU0158, and responses were compared to those to the well-studied CF pathogen Pseudomonas aeruginosa In parallel, mice were also infected with a polar flagellin mutant of B. dolosa to examine the role of flagella in B. dolosa lung colonization. The results showed a higher persistence in the host by B. dolosa strains, and yet, neutrophil recruitment and cytokine production were lower than those with P. aeruginosa The ability of host immune cells to recognize B. dolosa was then assessed, B. dolosa induced a robust cytokine response in cultured cells, and this effect was dependent on the flagella only when bacteria were dead. Together, these results suggest that B. dolosa can be recognized by host cells in vitro but may avoid or suppress the host immune response in vivo through unknown mechanisms. B. dolosa was then compared to other Burkholderia species and found to induce similar levels of cytokine production despite being internalized by macrophages more than Burkholderia cenocepacia strains. These data suggest that B. dolosa AU0158 may act differently with host cells and is recognized differently by immune systems than are other Burkholderia strains or species.
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Lewis ERG, Torres AG. The art of persistence-the secrets to Burkholderia chronic infections. Pathog Dis 2016; 74:ftw070. [PMID: 27440810 DOI: 10.1093/femspd/ftw070] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/14/2016] [Indexed: 12/11/2022] Open
Abstract
The Gram-negative proteobacteria genus Burkholderia encompasses multiple bacterial species that are pathogenic to humans and other vertebrates. Two pathogenic species of interest within this genus are Burkholderia pseudomallei (Bpm) and the B. cepacia complex (Bcc); the former is the causative agent of melioidosis in humans and other mammals, and the latter is associated with pneumonia in immunocompromised patients. One understudied and shared characteristic of these two pathogenic groups is their ability to persist and establish chronic infection within the host. In this review, we will explore the depth of knowledge about chronic infections caused by persistent Bpm and Bcc. We examine the host risk factors and immune responses associated with more severe chronic infections. We also discuss host adaptation and phenotypes associated with persistent Burkholderia species. Lastly, we survey how other intracellular bacteria associated with chronic infections are combatted and explore possible future applications to target Burkholderia Our goal is to highlight understudied areas that should be addressed for a more thorough understanding of chronic Burkholderia infections and how to combat them.
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Affiliation(s)
- Eric R G Lewis
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
| | - Alfredo G Torres
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA Department of Pathology, Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 7555-1070, USA
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Abstract
Burkholderia cepacia complex (Bcc) species are a group of Gram-negative opportunistic pathogens that infect the airways of cystic fibrosis patients, and occasionally they infect other immunocompromised patients. Bcc bacteria display high-level multidrug resistance and chronically persist in the infected host while eliciting robust inflammatory responses. Studies using macrophages, neutrophils, and dendritic cells, combined with advances in the genetic manipulation of these bacteria, have increased our understanding of the molecular mechanisms of virulence in these pathogens and the molecular details of cell-host responses triggering inflammation. This article discusses our current view of the intracellular survival of Burkholderia cenocepacia within macrophages.
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Affiliation(s)
- Miguel A. Valvano
- Centre for Infection and Immunity, Queen’s University Belfast, Belfast, BT9 7AE, UK
- Centre for Human Immunology, Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1, Canada
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Silva EB, Dow SW. Development of Burkholderia mallei and pseudomallei vaccines. Front Cell Infect Microbiol 2013; 3:10. [PMID: 23508691 PMCID: PMC3598006 DOI: 10.3389/fcimb.2013.00010] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 02/20/2013] [Indexed: 12/16/2022] Open
Abstract
Burkholderia mallei and Burkholderia pseudomallei are Gram-negative bacteria that cause glanders and melioidosis, respectively. Inhalational infection with either organism can result in severe and rapidly fatal pneumonia. Inoculation by the oral and cutaneous routes can also produce infection. Chronic infection may develop after recovery from acute infection with both agents, and control of infection with antibiotics requires prolonged treatment. Symptoms for both meliodosis and glanders are non-specific, making diagnosis difficult. B. pseudomallei can be located in the environment, but in the host, B. mallei and B. psedomallei are intracellular organisms, and infection results in similar immune responses to both agents. Effective early innate immune responses are critical to controlling the early phase of the infection. Innate immune signaling molecules such as TLR, NOD, MyD88, and pro-inflammatory cytokines such as IFN-γ and TNF-α play key roles in regulating control of infection. Neutrophils and monocytes are critical cells in the early infection for both microorganisms. Both monocytes and macrophages are necessary for limiting dissemination of B. pseudomallei. In contrast, the role of adaptive immune responses in controlling Burkholderia infection is less well understood. However, T cell responses are critical for vaccine protection from Burkholderia infection. At present, effective vaccines for prevention of glanders or meliodosis have not been developed, although recently development of Burkholderia vaccines has received renewed attention. This review will summarize current and past approaches to develop B. mallei and B. pseudomalllei vaccines, with emphasis on immune mechanisms of protection and the challenges facing the field. At present, immunization with live attenuated bacteria provides the most effective and durable immunity, and it is important therefore to understand the immune correlates of protection induced by live attenuated vaccines. Subunit vaccines have typically provided less robust immunity, but are safer to administer to a wider variety of people, including immune compromised individuals because they do not reactivate or cause disease. The challenges facing B. mallei and B. pseudomalllei vaccine development include identification of broadly protective antigens, design of efficient vaccine delivery and adjuvant systems, and a better understanding of the correlates of protection from both acute and chronic infection.
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Affiliation(s)
- Ediane B Silva
- Department of Microbiology, Immunology, and Pathology, Regional Center of Excellence in Emerging Diseases and Bioterrorism, Colorado State University Ft. Collins, CO, USA
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Saussereau E, Debarbieux L. Bacteriophages in the experimental treatment of Pseudomonas aeruginosa infections in mice. Adv Virus Res 2012; 83:123-41. [PMID: 22748810 DOI: 10.1016/b978-0-12-394438-2.00004-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The regular increase of drug-resistant pathogens has been a major force in the renewed interest in the use of bacteriophages as therapeutics. In addition to experience acquired in eastern Europe where bacteriophages have been used to treat bacterial infections in humans, in Western countries only experimental models have been developed until recently. The Gram-negative bacterium Pseudomonas aeruginosa is an opportunistic pathogen causing particularly severe infections in cystic fibrosis patients. Several experimental models in mice have yielded encouraging results for the use of bacteriophages to treat or prevent septicemia, skin and lungs infections caused by P. aeruginosa. Now, a phase II clinical trial conducted in the United Kingdom provides evidence for the efficacy of bacteriophage treatments in chronic otitis due to antibiotic-resistant P. aeruginosa strains. Together with experimental models, these results provide an incentive to develop more research and clinical studies to fully appreciate the benefits of the use of bacteriophages in medicine.
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Affiliation(s)
- Emilie Saussereau
- Institut Pasteur, Molecular Biology of the Gene in Extremophiles Unit, Department of Microbiology, Paris, France
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Rosales-Reyes R, Aubert DF, Tolman JS, Amer AO, Valvano MA. Burkholderia cenocepacia type VI secretion system mediates escape of type II secreted proteins into the cytoplasm of infected macrophages. PLoS One 2012; 7:e41726. [PMID: 22848580 PMCID: PMC3405007 DOI: 10.1371/journal.pone.0041726] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 06/27/2012] [Indexed: 11/18/2022] Open
Abstract
Burkholderia cenocepacia is an opportunistic pathogen that survives intracellularly in macrophages and causes serious respiratory infections in patients with cystic fibrosis. We have previously shown that bacterial survival occurs in bacteria-containing membrane vacuoles (BcCVs) resembling arrested autophagosomes. Intracellular bacteria stimulate IL-1β secretion in a caspase-1-dependent manner and induce dramatic changes to the actin cytoskeleton and the assembly of the NADPH oxidase complex onto the BcCV membrane. A Type 6 secretion system (T6SS) is required for these phenotypes but surprisingly it is not required for the maturation arrest of the BcCV. Here, we show that macrophages infected with B. cenocepacia employ the NLRP3 inflammasome to induce IL-1β secretion and pyroptosis. Moreover, IL-1β secretion by B. cenocepacia-infected macrophages is suppressed in deletion mutants unable to produce functional Type VI, Type IV, and Type 2 secretion systems (SS). We provide evidence that the T6SS mediates the disruption of the BcCV membrane, which allows the escape of proteins secreted by the T2SS into the macrophage cytoplasm. This was demonstrated by the activity of fusion derivatives of the T2SS-secreted metalloproteases ZmpA and ZmpB with adenylcyclase. Supporting this notion, ZmpA and ZmpB are required for efficient IL-1β secretion in a T6SS dependent manner. ZmpA and ZmpB are also required for the maturation arrest of the BcCVs and bacterial intra-macrophage survival in a T6SS-independent fashion. Our results uncover a novel mechanism for inflammasome activation that involves cooperation between two bacterial secretory pathways, and an unanticipated role for T2SS-secreted proteins in intracellular bacterial survival.
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Affiliation(s)
- Roberto Rosales-Reyes
- Centre for Human Immunology, Department of Microbiology and Immunology, The University of Western Ontario, London, Ontario, Canada
- Laboratorio de Infectología, Microbiología e Inmunología Clínicas, Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, México
| | - Daniel F. Aubert
- Centre for Human Immunology, Department of Microbiology and Immunology, The University of Western Ontario, London, Ontario, Canada
| | - Jennifer S. Tolman
- Centre for Human Immunology, Department of Microbiology and Immunology, The University of Western Ontario, London, Ontario, Canada
| | - Amal O. Amer
- Centre for Microbial Interface Biology, Department of Microbial Infection and Immunity and the Department of Internal Medicine, Ohio State University, Columbus, Ohio, United States of America
| | - Miguel A. Valvano
- Centre for Human Immunology, Department of Microbiology and Immunology, The University of Western Ontario, London, Ontario, Canada
- * E-mail:
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Famakin B, Mou Y, Spatz M, Lawal M, Hallenbeck J. Downstream Toll-like receptor signaling mediates adaptor-specific cytokine expression following focal cerebral ischemia. J Neuroinflammation 2012; 9:174. [PMID: 22799573 PMCID: PMC3419098 DOI: 10.1186/1742-2094-9-174] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 07/16/2012] [Indexed: 01/18/2023] Open
Abstract
Background Deletion of some Toll-like receptors (TLRs) affords protection against cerebral ischemia, but disruption of their known major downstream adaptors does not. To determine whether compensation in the production of downstream effectors by one pathway when the other is disrupted can explain these findings, we examined cytokine/chemokine expression and inflammatory infiltrates in wild-type (WT), MyD88−/− and TRIF-mutant mice following permanent middle cerebral artery occlusion (pMCAO). Methods Cytokine/chemokine expression was measured with a 25-plex bead array in the serum and brains of all three groups of mice at baseline (no surgery/naïve) and at 3 hours and 24 hours following pMCAO. Brain inflammatory and neutrophil infiltrates were examined 24 hours following pMCAO. Results IL-6, keratinocyte chemoattractant (KC), granulocyte colony-stimulating factor (G-CSF) and IL-10 were significantly decreased in MyD88−/− mice compared to WT mice following pMCAO. Significantly, decreased levels of the neutrophil chemoattractants KC and G-CSF corresponded with a trend toward fewer neutrophils in the brains of MyD88−/− mice. IP-10 was significantly decreased when either pathway was disrupted. MIP-1α was significantly decreased in TRIF-mutant mice, consistent with TRIF-dependent production. Finally, MyD88−/− mice showed elevations of a number of Th2 cytokines, such as IL-13, at baseline, which became significantly decreased following pMCAO. Conclusions Both MyD88 and TRIF mediate pathway-specific cytokine production following focal cerebral ischemia. Our results also suggest a compensatory Th2-type skew at baseline in MyD88−/− mice and a paradoxical switch to a Th1 phenotype following focal cerebral ischemia. Finally, the MyD88 pathway directs the expression of neutrophil chemoattractants following cerebral ischemia.
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Affiliation(s)
- Bolanle Famakin
- Stroke Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 10 Center Drive, Building 10, Room 5B06, MSC 1401, Bethesda, MD 20892-1401, USA.
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MyD88-dependent recruitment of monocytes and dendritic cells required for protection from pulmonary Burkholderia mallei infection. Infect Immun 2011; 80:110-20. [PMID: 22025508 DOI: 10.1128/iai.05819-11] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The Gram-negative bacterium Burkholderia mallei causes rapidly fatal illness in equines and humans when contracted by inhalation and also has the potential to be used as a bioweapon. However, little is known regarding the early innate immune responses and signaling mechanisms required to generate protection from pneumonic B. mallei infection. We showed previously that monocyte chemoattractant protein 1 (MCP-1) was a critical chemokine required for protection from pneumonic B. mallei infection. We have now extended those studies to identify key Toll-like receptor (TLR) signaling pathways, effector cells, and cytokines required for protection from respiratory B. mallei infection. We found that MyD88-/- mice were highly susceptible to pulmonary challenge with B. mallei and had significantly short survival times, increased bacterial burdens, and severe organ pathology compared to wild-type mice. Notably, MyD88-/- mice had significantly fewer monocytes and dendritic cells (DCs) in lung tissues and airways than infected wild-type mice despite markedly higher bacterial burdens. The MyD88-/- mice were also completely unable to produce gamma interferon (IFN-γ) at any time points following infection. In wild-type mice, NK cells were the primary cells producing IFN-γ in the lungs following B. mallei infection, while DCs and monocytes were the primary cellular sources of interleukin-12 (IL-12) production. Treatment with recombinant IFN-γ (rIFN-γ) was able to significantly restore protective immunity in MyD88-/- mice. Thus, we conclude that the MyD88-dependent recruitment of inflammatory monocytes and DCs to the lungs and the local production of IL-12, followed by NK cell production of IFN-γ, are the key initial cellular responses required for early protection from B. mallei infection.
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Jyot J, Balloy V, Jouvion G, Verma A, Touqui L, Huerre M, Chignard M, Ramphal R. Type II secretion system of Pseudomonas aeruginosa: in vivo evidence of a significant role in death due to lung infection. J Infect Dis 2011; 203:1369-77. [PMID: 21502078 DOI: 10.1093/infdis/jir045] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The role of toxins secreted by the type II secretion system (T2SS) of Pseudomonas aeruginosa during lung infection has been uncertain despite decades of research. METHODS Using a model of pneumonia in Toll-like receptor (TLR) 2,4(-/-) mice, we reexamined the role of the T2SS system. Flagellin-deficient mutants of P. aeruginosa, with mutations in the T2SS and/or T3SS, were used to infect mice. Mice were followed up for survival, with some killed at different intervals to study bacterial clearance, inflammatory responses, and lung pathology. RESULTS Strains carrying either secretion system were lethal for mice. Double mutants were avirulent. The T3SS(+) strains killed mice within a day, and the T2SS(+) strains killed them later. Mice infected with a strain that had only the T2SS were unable to eradicate the organism from the lungs, whereas those infected with a T2SS-T3SS double deletion were able to clear this mutant. Death caused by the T2SS(+) strain was accompanied by a >50-fold increase in bacterial counts and higher numbers of viable intracellular bacteria. CONCLUSIONS The T2SS of P. aeruginosa may play a role in death from pneumonia, but its action is delayed. These data suggest that antitoxin strategies against this organism will require measures against the toxins secreted by both T2SS and T3SS.
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Affiliation(s)
- Jeevan Jyot
- Department of Medicine, University of Florida, Gainesville, USA
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Cremer TJ, Shah P, Cormet-Boyaka E, Valvano MA, Butchar JP, Tridandapani S. Akt-mediated proinflammatory response of mononuclear phagocytes infected with Burkholderia cenocepacia occurs by a novel GSK3β-dependent, IκB kinase-independent mechanism. THE JOURNAL OF IMMUNOLOGY 2011; 187:635-43. [PMID: 21697459 DOI: 10.4049/jimmunol.1003034] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The environmental bacterium Burkholderia cenocepacia causes opportunistic lung infections in immunocompromised individuals, particularly in patients with cystic fibrosis. Infections in these patients are associated with exacerbated inflammation leading to rapid decay of lung function, and in some cases resulting in cepacia syndrome, which is characterized by a fatal acute necrotizing pneumonia and sepsis. B. cenocepacia can survive intracellularly in macrophages by altering the maturation of the phagosome, but very little is known on macrophage responses to the intracellular infection. In this study, we have examined the role of the PI3K/Akt signaling pathway in B. cenocepacia-infected monocytes and macrophages. We show that PI3K/Akt activity was required for NF-κB activity and the secretion of proinflammatory cytokines during infection with B. cenocepacia. In contrast to previous observations in epithelial cells infected with other Gram-negative bacteria, Akt did not enhance IκB kinase or NF-κB p65 phosphorylation, but rather inhibited GSK3β, a negative regulator of NF-κB transcriptional activity. This novel mechanism of modulation of NF-κB activity may provide a unique therapeutic target for controlling excessive inflammation upon B. cenocepacia infection.
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Affiliation(s)
- Thomas J Cremer
- Department of Internal Medicine, The Ohio State University Medical Center, Columbus, OH 43210, USA
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Morello E, Saussereau E, Maura D, Huerre M, Touqui L, Debarbieux L. Pulmonary bacteriophage therapy on Pseudomonas aeruginosa cystic fibrosis strains: first steps towards treatment and prevention. PLoS One 2011; 6:e16963. [PMID: 21347240 PMCID: PMC3039662 DOI: 10.1371/journal.pone.0016963] [Citation(s) in RCA: 178] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Accepted: 01/15/2011] [Indexed: 12/22/2022] Open
Abstract
Multidrug-resistant bacteria are the cause of an increasing number of deadly pulmonary infections. Because there is currently a paucity of novel antibiotics, phage therapy--the use of specific viruses that infect bacteria--is now more frequently being considered as a potential treatment for bacterial infections. Using a mouse lung-infection model caused by a multidrug resistant Pseudomonas aeruginosa mucoid strain isolated from a cystic fibrosis patient, we evaluated bacteriophage treatments. New bacteriophages were isolated from environmental samples and characterized. Bacteria and bacteriophages were applied intranasally to the immunocompetent mice. Survival was monitored and bronchoalveolar fluids were analysed. Quantification of bacteria, bacteriophages, pro-inflammatory and cytotoxicity markers, as well as histology and immunohistochemistry analyses were performed. A curative treatment (one single dose) administrated 2 h after the onset of the infection allowed over 95% survival. A four-day preventive treatment (one single dose) resulted in a 100% survival. All of the parameters measured correlated with the efficacy of both curative and preventive bacteriophage treatments. We also showed that in vitro optimization of a bacteriophage towards a clinical strain improved both its efficacy on in vivo treatments and its host range on a panel of 20 P. aeruginosa cystic fibrosis strains. This work provides an incentive to develop clinical studies on pulmonary bacteriophage therapy to combat multidrug-resistant lung infections.
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Affiliation(s)
- Eric Morello
- Molecular Biology of the Gene in Extremophiles
Unit, Department of Microbiology, Institut Pasteur, Paris, France
| | - Emilie Saussereau
- Molecular Biology of the Gene in Extremophiles
Unit, Department of Microbiology, Institut Pasteur, Paris, France
| | - Damien Maura
- Molecular Biology of the Gene in Extremophiles
Unit, Department of Microbiology, Institut Pasteur, Paris, France
| | - Michel Huerre
- Histotechnology and Pathology Unit, Department
of Infection and Epidemiology, Institut Pasteur, Paris, France
| | - Lhousseine Touqui
- Innate Host Defense and Inflammation Unit,
Department of Infection and Epidemiology, Institut Pasteur, Paris,
France
- INSERM, U874, Paris, France
| | - Laurent Debarbieux
- Molecular Biology of the Gene in Extremophiles
Unit, Department of Microbiology, Institut Pasteur, Paris, France
- * E-mail:
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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.
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Affiliation(s)
- Erin I Lafferty
- Division of Experimental Medicine, McGill University, Montréal, Québec H3A 1A3, Canada.
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MyD88 signaling is indispensable for primary influenza A virus infection but dispensable for secondary infection. J Virol 2010; 84:12713-22. [PMID: 20943980 DOI: 10.1128/jvi.01675-10] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Recent studies have revealed that innate immunity is involved in the development of adaptive immune responses; however, its role in protection is not clear. In order to elucidate the exact role of Toll-like receptor (TLR) or RIG-I-like receptor (RLR) signaling on immunogenicity and protective efficacy against influenza A virus infection (A/PR/8/34 [PR8]; H1N1), we adapted several innate signal-deficient mice (e.g., TRIF(-/-), MyD88(-/-), MyD88(-/-) TRIF(-/-), TLR3(-/-) TLR7(-/-), and IPS-1(-/-)). In this study, we found that MyD88 signaling was required for recruitment of CD11b(+) granulocytes, production of early inflammatory cytokines, optimal proliferation of CD4 T cells, and production of Th1 cytokines by T cells. However, PR8 virus-specific IgG and IgA antibody levels in both systemic and mucosal compartments were normal in TLR- and RLR-deficient mice. To further assess the susceptibility of these mice to influenza virus infection, protective efficacy was determined after primary or secondary lethal challenge. We found that MyD88(-/-) and MyD88(-/-) TRIF(-/-) mice were more susceptible to primary influenza virus infection than the B6 mice but were fully protected against homologous (H1N1) and heterosubtypic (H5N2) secondary infection when primed with a nonlethal dose of PR8 virus. Taken together, these results show that MyD88 signaling plays an important role for resisting primary influenza virus infection but is dispensable for protection against a secondary lethal challenge.
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Cunha LG, Assis MC, Machado GB, Assef AP, Marques EA, Leão RS, Saliba AM, Plotkowski MC. Potential mechanisms underlying the acute lung dysfunction and bacterial extrapulmonary dissemination during Burkholderia cenocepacia respiratory infection. Respir Res 2010; 11:4. [PMID: 20082687 PMCID: PMC2817657 DOI: 10.1186/1465-9921-11-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Accepted: 01/18/2010] [Indexed: 01/06/2023] Open
Abstract
Background Burkholderia cenocepacia, an opportunistic pathogen that causes lung infections in cystic fibrosis (CF) patients, is associated with rapid and usually fatal lung deterioration due to necrotizing pneumonia and sepsis, a condition known as cepacia syndrome. The key bacterial determinants associated with this poor clinical outcome in CF patients are not clear. In this study, the cytotoxicity and procoagulant activity of B. cenocepacia from the ET-12 lineage, that has been linked to the cepacia syndrome, and four clinical isolates recovered from CF patients with mild clinical courses were analysed in both in vitro and in vivo assays. Methods B. cenocepacia-infected BEAS-2B epithelial respiratory cells were used to investigate the bacterial cytotoxicity assessed by the flow cytometric detection of cell staining with propidium iodide. Bacteria-induced procoagulant activity in cell cultures was assessed by a colorimetric assay and by the flow cytometric detection of tissue factor (TF)-bearing microparticles in cell culture supernatants. Bronchoalveolar lavage fluids (BALF) from intratracheally infected mice were assessed for bacterial proinflammatory and procoagulant activities as well as for bacterial cytotoxicity, by the detection of released lactate dehydrogenase. Results ET-12 was significantly more cytotoxic to cell cultures but clinical isolates Cl-2, Cl-3 and Cl-4 exhibited also a cytotoxic profile. ET-12 and CI-2 were similarly able to generate a TF-dependent procoagulant environment in cell culture supernatant and to enhance the release of TF-bearing microparticles from infected cells. In the in vivo assay, all bacterial isolates disseminated from the mice lungs, but Cl-2 and Cl-4 exhibited the highest rates of recovery from mice livers. Interestingly, Cl-2 and Cl-4, together with ET-12, exhibited the highest cytotoxicity. All bacteria were similarly capable of generating a procoagulant and inflammatory environment in animal lungs. Conclusion B. cenocepacia were shown to exhibit cytotoxic and procoagulant activities potentially implicated in bacterial dissemination into the circulation and acute pulmonary decline detected in susceptible CF patients. Improved understanding of the mechanisms accounting for B. cenocepacia-induced clinical decline has the potential to indicate novel therapeutic strategies to be included in the care B. cenocepacia-infected patients.
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Affiliation(s)
- Luiz G Cunha
- Departamento de Microbiologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Brazil
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