Host cell kinases, α5 and β1 integrins, and Rac1 signalling on the microtubule cytoskeleton are important for non-typable Haemophilus influenzae invasion of respiratory epithelial cells

López−Gómez, Antonio; Cano, Victoria; Moranta, David; Morey, Pau; Portillo, Francisco García‐del; Bengoechea, José A.; Garmendia, Junkal

doi:10.1099/mic.0.059972-0

Cited by 32 publications

(58 citation statements)

References 83 publications

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“…NTHi liquid cultures were grown in sBHI. NTHi375 is a genome-sequenced clinical isolate previously used in host-pathogen interplay studies (13,14,30).…”

Section: Methodsmentioning

confidence: 99%

“…Carcinomic human alveolar basal epithelial cells (A549, ATCC CCL-185) were maintained and seeded in 24-well tissue culture plates as described previously (14). Adhesion and invasion assays were performed and processed as previously described (13,14). 33 or 41°C 24 h before and during NTHi infection.…”

Section: Methodsmentioning

confidence: 99%

“…Our current understanding of the molecular mechanisms involved in NTHi infection remains limited, but identical strains have been repeatedly isolated from the lungs of COPD patients in serial clinic visits, suggesting that NTHi presents features that promote chronic infection (7,8). NTHi is a facultative intracellular patho-gen (9)(10)(11)(12)(13)(14)(15)(16), and epithelial invasion may allow bacterial cells to temporarily evade the immune system and/or therapeutic interventions. Indeed, a correlation between the occurrence of intracellular NTHi and persistent infection has been proposed (17,18).…”

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confidence: 99%

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Genome Expression Profiling-Based Identification and Administration Efficacy of Host-Directed Antimicrobial Drugs against Respiratory Infection by Nontypeable Haemophilus influenzae

Euba

Moleres

Segura

et al. 2015

Antimicrob Agents Chemother

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Therapies that are safe, effective, and not vulnerable to developing resistance are highly desirable to counteract bacterial infections. Host-directed therapeutics is an antimicrobial approach alternative to conventional antibiotics based on perturbing host pathways subverted by pathogens during their life cycle by using host-directed drugs. In this study, we identified and evaluated the efficacy of a panel of host-directed drugs against respiratory infection by nontypeable Haemophilus influenzae (NTHi). NTHi is an opportunistic pathogen that is an important cause of exacerbation of chronic obstructive pulmonary disease (COPD). We screened for host genes differentially expressed upon infection by the clinical isolate NTHi375 by analyzing cell whole-genome expression profiling and identified a repertoire of host target candidates that were pharmacologically modulated. Based on the proposed relationship between NTHi intracellular location and persistence, we hypothesized that drugs perturbing host pathways used by NTHi to enter epithelial cells could have antimicrobial potential against NTHi infection. Interfering drugs were tested for their effects on bacterial and cellular viability, on NTHi-epithelial cell interplay, and on mouse pulmonary infection. Glucocorticoids and statins lacked in vitro and/or in vivo efficacy. Conversely, the sirtuin-1 activator resveratrol showed a bactericidal effect against NTHi, and the PDE4 inhibitor rolipram showed therapeutic efficacy by lowering NTHi375 counts intracellularly and in the lungs of infected mice. PDE4 inhibition is currently prescribed in COPD, and resveratrol is an attractive geroprotector for COPD treatment. Together, these results expand our knowledge of NTHi-triggered host subversion and frame the antimicrobial potential of rolipram and resveratrol against NTHi respiratory infection.

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“…NTHi liquid cultures were grown in sBHI. NTHi375 is a genome-sequenced clinical isolate previously used in host-pathogen interplay studies (13,14,30).…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

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Genome Expression Profiling-Based Identification and Administration Efficacy of Host-Directed Antimicrobial Drugs against Respiratory Infection by Nontypeable Haemophilus influenzae

Euba

Moleres

Segura

et al. 2015

Antimicrob Agents Chemother

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“…NTHI 375 is a child otitis media isolate recovered from an ear sample (47,48), whose interplay with the host was previously characterized (51,55,56). The MIC of AZM for NTHI 375 is 0.25 g/ml, and accordingly, it was classified as susceptible.…”

Section: Selection Of Two Nthi Clinical Isolates With Different Suscementioning

confidence: 99%

Relationship between Azithromycin Susceptibility and Administration Efficacy for Nontypeable Haemophilus influenzae Respiratory Infection

Euba

Moleres

Viadas

et al. 2015

Antimicrob Agents Chemother

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“…Internalization of NTHI is also promoted by macropi-nocytosis, ␤-glucan receptor (␤GR)-mediated endocytosis in macrophages, and platelet-activating factor receptor (PAFR)-mediated endocytosis in epithelial cells (13,19,24,25). The bacterial ligand for PAFR is phosphorylcholine (ChoP), and while strains with either ChoP-positive or ChoP-negative lipooligosaccharide (LOS) induce differential host cell signaling, it seems that all strains induce phosphatidylinositol-3-kinase (PI3K) signaling, phospholipase activity, and calcium release from intracellular stores (20,22,24,25,33). NTHI has consistently been found within vesicles positive for markers of endolysosomal trafficking (20,22).…”

mentioning

confidence: 99%

Internalization and Trafficking of Nontypeable Haemophilus influenzae in Human Respiratory Epithelial Cells and Roles of IgA1 Proteases for Optimal Invasion and Persistence

2014

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Nontypeable Haemophilus influenzae (NTHI) is a leading cause of opportunistic infections of the respiratory tract in children and adults. Although considered an extracellular pathogen, NTHI has been observed repeatedly within and between cells of the human respiratory tract, and these observations have been correlated to symptomatic infection. These findings are intriguing in light of the knowledge that NTHI persists in the respiratory tract despite antibiotic therapy and the development of bactericidal antibodies. We hypothesized that intracellular NTHI avoids, escapes, or neutralizes the endolysosomal pathway and persists within human respiratory epithelial cells and that human IgA1 proteases are required for optimal internalization and persistence of NTHI. Virtually all strains encode a human IgA1 protease gene, igaA, and we previously characterized a novel human IgA1 protease gene, igaB, that is associated with disease-causing strains and is homologous to the IgA1 protease that is unique to pathogenic Neisseria spp. Here, we show that NTHI invades human bronchial epithelial cells in vitro in a lipid raft-independent manner, is subsequently trafficked via the endolysosomal pathway, and is killed in lysosomes after variable durations of persistence. IgaA is required for optimal invasion. IgaB appears to play little or no role in adherence or invasion but is required for optimal intracellular persistence of NTHI. IgaB cleaves lysosome-associated membrane protein 1 (LAMP1) at pHs characteristic of the plasma membrane, early endosome, late endosome, and lysosome. However, neither IgA1 protease inhibits acidification of intracellular vesicles containing NTHI. NTHI IgA1 proteases play important but different roles in NTHI invasion and trafficking in respiratory epithelial cells. Nontypeable Haemophilus influenzae (NTHI) is a Gram-negative, human-exclusive commensal bacterium of the nasopharynx and is a leading cause of opportunistic infections in the upper and lower respiratory tracts, including otitis media, sinusitis, conjunctivitis, community-acquired pneumonia, and exacerbations of chronic obstructive pulmonary disease (COPD) and of cystic fibrosis (1, 2).When a new strain of NTHI is acquired, the outcome depends on a variety of dynamic host and bacterial factors. Colonization and the transition from commensal to opportunistic pathogen require NTHI to resist host innate immune defenses, including nutrient sequestration, mucociliary clearance, antimicrobial peptides, secretory IgA1, and phagocytosis by immune cells or by epithelial cells. Bacterial counterresistance mechanisms under investigation include adhesins, antimicrobial peptide degradation, IgA1 protease, biofilm production, modification of surface-exposed lipooligosaccharide moieties, production of outer membrane vesicles (OMVs), and others (3-12). Understanding these factors will help identify targets for therapeutic intervention, as NTHI infections induce acquired immunity consisting largely of strain-specific bactericidal antibodies that afford littl...

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Host cell kinases, α5 and β1 integrins, and Rac1 signalling on the microtubule cytoskeleton are important for non-typable Haemophilus influenzae invasion of respiratory epithelial cells

Cited by 32 publications

References 83 publications

Genome Expression Profiling-Based Identification and Administration Efficacy of Host-Directed Antimicrobial Drugs against Respiratory Infection by Nontypeable Haemophilus influenzae

Genome Expression Profiling-Based Identification and Administration Efficacy of Host-Directed Antimicrobial Drugs against Respiratory Infection by Nontypeable Haemophilus influenzae

Relationship between Azithromycin Susceptibility and Administration Efficacy for Nontypeable Haemophilus influenzae Respiratory Infection

Internalization and Trafficking of Nontypeable Haemophilus influenzae in Human Respiratory Epithelial Cells and Roles of IgA1 Proteases for Optimal Invasion and Persistence

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