scholarly journals Role of the Zinc Uptake ABC Transporter of Moraxella catarrhalis in Persistence in the Respiratory Tract

2013 ◽  
Vol 81 (9) ◽  
pp. 3406-3413 ◽  
Author(s):  
Timothy F. Murphy ◽  
Aimee L. Brauer ◽  
Charmaine Kirkham ◽  
Antoinette Johnson ◽  
Mary Koszelak-Rosenblum ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Respiratory Tract ◽  
Abc Transporter ◽  
Divalent Cations ◽  
Zinc Uptake ◽  
Wild Type ◽  
Human Respiratory Tract ◽  
Respiratory Epithelial Cells ◽  
Content Type ◽  
Respiratory Epithelial

ABSTRACTMoraxella catarrhalisis a human respiratory tract pathogen that causes otitis media in children and lower respiratory tract infections in adults with chronic obstructive pulmonary disease. We have identified and characterized a zinc uptake ABC transporter that is present in all strains ofM. catarrhalistested. A mutant in which theznugene cluster is knocked out shows markedly impaired growth compared to the wild type in medium that contains trace zinc; growth is restored to wild-type levels by supplementing medium with zinc but not with other divalent cations. Thermal-shift assays showed that the purified recombinant substrate binding protein ZnuA binds zinc but does not bind other divalent cations. Invasion assays with human respiratory epithelial cells demonstrated that the zinc ABC transporter ofM. catarrhalisis critical for invasion of respiratory epithelial cells, an observation that is especially relevant because an intracellular reservoir ofM. catarrhalisis present in the human respiratory tract and this reservoir is important for persistence. Theznuknockout mutant showed marked impairment in its capacity to persist in the respiratory tract compared to the wild type in a mouse pulmonary clearance model. We conclude that the zinc uptake ABC transporter mediates uptake of zinc in environments with very low zinc concentrations and is critical for full virulence ofM. catarrhalisin the respiratory tract in facilitating intracellular invasion of epithelial cells and persistence in the respiratory tract.

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

2013 ◽  
Vol 82 (1) ◽  
pp. 433-444 ◽  
Author(s):  
Cara F. Clementi ◽  
Anders P. Håkansson ◽  
Timothy F. Murphy
Keyword(s):  
Epithelial Cells ◽  
Respiratory Tract ◽  
Haemophilus Influenzae ◽  
Opportunistic Infections ◽  
Protease Gene ◽  
Respiratory Epithelial Cells ◽  
Content Type ◽  
Iga1 Protease ◽  
Human Respiratory Epithelial Cells ◽  
Respiratory Epithelial

ABSTRACTNontypeableHaemophilus 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 pathogenicNeisseriaspp. Here, we show that NTHI invades human bronchial epithelial cellsin vitroin 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.

scholarly journals Primary differentiated respiratory epithelial cells respond to apical measles virus infection by shedding multinucleated giant cells

2021 ◽  
Vol 118 (11) ◽  
pp. e2013264118
Author(s):  
Wen-Hsuan W. Lin ◽  
Annie J. Tsay ◽  
Erin N. Lalime ◽  
Andrew Pekosz ◽  
Diane E. Griffin
Keyword(s):  
Epithelial Cells ◽  
Respiratory Tract ◽  
Measles Virus ◽  
Giant Cells ◽  
Childhood Mortality ◽  
Apical Surface ◽  
Respiratory Epithelial Cells ◽  
Systemic Spread ◽  
Large Clusters ◽  
Respiratory Epithelial

Measles virus (MeV) is highly infectious by the respiratory route and remains an important cause of childhood mortality. However, the process by which MeV infection is efficiently established in the respiratory tract is controversial with suggestions that respiratory epithelial cells are not susceptible to infection from the apical mucosal surface. Therefore, it has been hypothesized that infection is initiated in lung macrophages or dendritic cells and that epithelial infection is subsequently established through the basolateral surface by infected lymphocytes. To better understand the process of respiratory tract initiation of MeV infection, primary differentiated respiratory epithelial cell cultures were established from rhesus macaque tracheal and nasal tissues. Infection of these cultures with MeV from the apical surface was more efficient than from the basolateral surface with shedding of viable MeV-producing multinucleated giant cell (MGC) syncytia from the surface. Despite presence of MGCs and infectious virus in supernatant fluids after apical infection, infected cells were not detected in the adherent epithelial sheet and transepithelial electrical resistance was maintained. After infection from the basolateral surface, epithelial damage and large clusters of MeV-positive cells were observed. Treatment with fusion inhibitory peptides showed that MeV production after apical infection was not dependent on infection of the basolateral surface. These results are consistent with the hypothesis that MeV infection is initiated by apical infection of respiratory epithelial cells with subsequent infection of lymphoid tissue and systemic spread.

scholarly journals Viral Coinfection Replaces Effects of Suilysin onStreptococcus suisAdherence to and Invasion of Respiratory Epithelial Cells Grown under Air-Liquid Interface Conditions

2019 ◽  
Vol 87 (8) ◽  
Author(s):  
Fandan Meng ◽  
Jie Tong ◽  
Désirée Vötsch ◽  
Ju-Yi Peng ◽  
Xuehui Cai ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Bacterial Infection ◽  
Liquid Interface ◽  
Influenza Viruses ◽  
Striking Difference ◽  
Respiratory Epithelial Cells ◽  
Content Type ◽  
Secondary Bacterial Infection ◽  
Respiratory Epithelial ◽  
Air Liquid Interface

ABSTRACTStreptococcus suisis an important zoonotic pathogen which can infect humans and pigs worldwide, posing a potential risk to global public health. Suilysin, a pore-forming cholesterol-dependent cytolysin, is considered to play an important role in the pathogenesis ofS. suisinfections. It is known that infection with influenza A viruses may favor susceptibility to secondary bacterial infection, resulting in more severe disease and increased mortality. However, the molecular mechanisms underlying these coinfections are incompletely understood. Applying highly differentiated primary porcine respiratory epithelial cells grown under air-liquid interface (ALI) conditions, we analyzed the contribution of swine influenza viruses (SIV) to the virulence ofS. suis, with a special focus on its cytolytic toxin, suilysin. We found that during secondary bacterial infection, suilysin ofS. suiscontributed to the damage of well-differentiated respiratory epithelial cells in the early stage of infection, whereas the cytotoxic effects induced by SIV became prominent at later stages of infection. Prior infection by SIV enhanced the adherence to and colonization of porcine airway epithelial cells by a wild-type (wt)S. suisstrain and a suilysin-negativeS. suismutant in a sialic acid-dependent manner. A striking difference was observed with respect to bacterial invasion. After bacterial monoinfection, only the wtS. suisstrain showed an invasive phenotype, whereas the mutant remained adherent. When the epithelial cells were preinfected with SIV, the suilysin-negative mutant also showed an invasion capacity. Therefore, we propose that coinfection with SIV may compensate for the lack of suilysin in the adherence and invasion process of suilysin-negativeS. suis.

scholarly journals All-trans retinoic acid mediates DUOX2 expression and function in respiratory tract epithelium

2010 ◽  
Vol 299 (2) ◽  
pp. L215-L221 ◽  
Author(s):  
Angela Lee Linderholm ◽  
June Onitsuka ◽  
Changhong Xu ◽  
Maggie Chiu ◽  
Wai-Ming Lee ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Epithelial Cells ◽  
Respiratory Tract ◽  
Fold Increase ◽  
Respiratory Epithelial Cells ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid ◽  
Mrna And Protein Expression ◽  
And Function ◽  
Respiratory Epithelial

DUOX1 and DUOX2 are members of the NADPH oxidase family that are specifically regulated to produce hydrogen peroxide in epithelia of the thyroid, gastrointestinal tract, and respiratory tract. The determinants of DUOX1 or DUOX2 expression in various tissues have not been established. Using respiratory tract epithelial cells as a model, we investigated changes in DUOX mRNA and protein expression during the first 10 days of differentiation. By comparing a respiratory tract cell line, HBE1, with primary tracheobronchial epithelial (TBE) cells, we determined that DUOX2 was significantly expressed only in cell conditions that included all- trans retinoic acid (ATRA). In HBE1 cells, DUOX2 mRNA increased 6-fold after ATRA treatment. Similarly, ATRA induced a 19-fold increase in DUOX2 mRNA expression in primary TBE cells with parallel increases in DUOX protein and DUOX-mediated H2O2 production as well. In addition, DUOX2 induction by rhinovirus required the presence of ATRA. ATRA had no effect on DUOX1 expression for all the conditions studied. Our data indicate that for respiratory epithelial cells, ATRA is important in the regulation of DUOX2 expression, function, and rhinovirus-mediated DUOX2 inducibility.

scholarly journals Expression of C-Reactive Protein in the Human Respiratory Tract

2001 ◽  
Vol 69 (3) ◽  
pp. 1747-1754 ◽  
Author(s):  
Jane M. Gould ◽  
Jeffrey N. Weiser
Keyword(s):  
Epithelial Cells ◽  
Respiratory Tract ◽  
Antimicrobial Effect ◽  
Acute Phase Reactant ◽  
C Reactive Protein ◽  
Human Respiratory Tract ◽  
Reactive Protein ◽  
Mucosal Surfaces ◽  
Human Sera ◽  
Respiratory Epithelial

ABSTRACT C-reactive protein (CRP) is a normal constituent of human sera synthesized by hepatocytes and induced by proinflammatory cytokines. The function of this acute-phase reactant includes activation of complement and enhancement of opsonophagocytosis. CRP binds to phosphorylcholine (ChoP), a constituent of eukaryotic membranes that is also found on the cell surface of major bacterial pathogens of the human respiratory tract, including Streptococcus pneumoniaeand Haemophilus influenzae. The presence of CRP on mucosal surfaces and role in innate immunity in the human respiratory tract where ChoP-containing organisms reside have not been previously studied. We have shown using a monoclonal antibody to CRP that CRP is present in inflamed (0.17 to 42 μg/ml) and uninflamed (<0.05 to 0.88 μg/ml) secretions from the human respiratory tract in sufficient quantities for an antimicrobial effect. In addition, the CRP gene was expressed in epithelial cells of the human respiratory tract using in situ hybridization on nasal polyps and reverse transcriptase PCR of pharyngeal cells in culture. The complement-dependent bactericidal activity of normal nasal airway surface fluid and sputum against ChoP-expressing H. influenzae was abolished when the secretions were pretreated to remove CRP. In summary, the results indicate that CRP is present in secretions of the human respiratory tract, that human respiratory epithelial cells are capable of CRP expression, and that this protein may contribute to bacterial clearance in the human respiratory tract.

scholarly journals The Vps/VacJ ABC Transporter Is Required for Intercellular Spread of Shigella flexneri

2013 ◽  
Vol 82 (2) ◽  
pp. 660-669 ◽  
Author(s):  
Chandra D. Carpenter ◽  
Benjamin J. Cooley ◽  
Brittany D. Needham ◽  
Carolyn R. Fisher ◽  
M. Stephen Trent ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Outer Membrane ◽  
Abc Transporter ◽  
Shigella Flexneri ◽  
Dual Function ◽  
Wild Type ◽  
Lipid Asymmetry ◽  
Content Type ◽  
Intercellular Spread ◽  
Phospholipid Profile

ABSTRACTThe Vps/VacJ ABC transporter system is proposed to function in maintaining the lipid asymmetry of the outer membrane. Mutations invpsorvacJinShigella flexneriresulted in increased sensitivity to lysis by the detergent sodium dodecyl sulfate (SDS), and thevpsCmutant showed minor differences in its phospholipid profile compared to the wild type.vpsCmutants were unable to form plaques in cultured epithelial cells, but this was not due to a failure to invade, to replicate intracellularly, or to polymerize actin via IcsA for movement within epithelial cells. The addition of the outer membrane phospholipase genepldAon a multicopy plasmid in avpsCorvacJmutant restored its resistance to SDS, suggesting a restoration of lipid asymmetry to the outer membrane. However, thepldAplasmid did not restore the mutant's ability to form plaques in tissue culture cells. Increased PldA levels also failed to restore the mutant's phospholipid profile to that of the wild type. We propose a dual function of the Vps/VacJ ABC transporter system inS. flexneriin both the maintenance of lipid asymmetry in the outer membrane and the intercellular spread of the bacteria between adjacent epithelial cells.

scholarly journals Pneumococcal Interactions with Epithelial Cells Are Crucial for Optimal Biofilm Formation and ColonizationIn VitroandIn Vivo

2012 ◽  
Vol 80 (8) ◽  
pp. 2744-2760 ◽  
Author(s):  
Laura R. Marks ◽  
G. Iyer Parameswaran ◽  
Anders P. Hakansson
Keyword(s):  
Epithelial Cells ◽  
Biofilm Formation ◽  
Invasive Disease ◽  
Respiratory Epithelial Cells ◽  
Symptomatic Infection ◽  
Content Type ◽  
Abiotic Surfaces ◽  
Horizontal Spread ◽  
Respiratory Epithelial

ABSTRACTThe human nasopharynx is the main reservoir forStreptococcus pneumoniae(the pneumococcus) and the source for both horizontal spread and transition to infection. Some clinical evidence indicates that nasopharyngeal carriage is harder to eradicate with antibiotics than is pneumococcal invasive disease, which may suggest that colonizing pneumococci exist in biofilm communities that are more resistant to antibiotics. While pneumococcal biofilms have been observed during symptomatic infection, their role in colonization and the role of host factors in this process have been less studied. Here, we show for the first time that pneumococci form highly structured biofilm communities during colonization of the murine nasopharynx that display increased antibiotic resistance. Furthermore, pneumococcal biofilms grown on respiratory epithelial cells exhibited phenotypes similar to those observed during colonizationin vivo, whereas abiotic surfaces produced less ordered and more antibiotic-sensitive biofilms. The importance of bacterial-epithelial cell interactions during biofilm formation was shown using both clinical strains with variable colonization efficacies and pneumococcal mutants with impaired colonization characteristicsin vivo. In both cases, the ability of strains to form biofilms on epithelial cells directly correlated with their ability to colonize the nasopharynxin vivo, with colonization-deficient strains forming less structured and more antibiotic-sensitive biofilms on epithelial cells, an association that was lost when grown on abiotic surfaces. Thus, these studies emphasize the importance of host-bacterial interactions in pneumococcal biofilm formation and provide the first experimental data to explain the high resistance of pneumococcal colonization to eradication by antibiotics.

scholarly journals Effect of Group A Streptococcal Cysteine Protease on Invasion of Epithelial Cells

1998 ◽  
Vol 66 (4) ◽  
pp. 1460-1466 ◽  
Author(s):  
Pei-Jane Tsai ◽  
Chih-Feng Kuo ◽  
Kuei-Yuan Lin ◽  
Yee-Shin Lin ◽  
Huan-Yao Lei ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cysteine Protease ◽  
Protease Activity ◽  
Extracellular Proteins ◽  
Wild Type ◽  
Respiratory Epithelial Cells ◽  
Group A ◽  
Human Respiratory Epithelial Cells ◽  
Respiratory Epithelial ◽  
Type Strains

ABSTRACT Cysteine protease of group A streptococci (GAS) is considered an important virulence factor. However, its role in invasiveness of GAS has not been investigated. We demonstrated in this study that two strains of protease-producing GAS had the ability to invade A-549 human respiratory epithelial cells. Isogenic protease mutants were constructed by using integrational plasmids to disrupt thespeB gene and confirmed by Southern hybridization and Western immunoblot analyses. No extracellular protease activity was produced by the mutants. The mutants had growth rates similar to those of the wild-type strains and produced normal levels of other extracellular proteins. When invading A-549 cells, the mutants had a two- to threefold decrease in activity compared to that of the wild-type strains. The invasion activity increased when the A-549 cells were incubated with purified cysteine protease and the mutant. However, blockage of the cysteine protease with a specific cysteine protease inhibitor, E-64, decreased the invasion activity of GAS. Intracellular growth of GAS was not found in A-549 cells. The presence or absence of protease activity did not affect the adhesive ability of GAS. These results suggested that streptococcal cysteine protease can enhance the invasion ability of GAS in human respiratory epithelial cells.

scholarly journals Modulation of Kingella kingae Adherence to Human Epithelial Cells by Type IV Pili, Capsule, and a Novel Trimeric Autotransporter

mBio ◽  
2012 ◽  
Vol 3 (5) ◽  
Author(s):  
Eric A. Porsch ◽  
Thomas E. Kehl-Fie ◽  
Joseph W. St. Geme
Keyword(s):  
Epithelial Cells ◽  
Young Children ◽  
Type Iv Pili ◽  
Upper Respiratory Tract ◽  
Respiratory Epithelial Cells ◽  
Kingella Kingae ◽  
Content Type ◽  
Type Iv ◽  
Human Epithelial Cells ◽  
Respiratory Epithelial

ABSTRACTKingella kingaeis an emerging bacterial pathogen that is being recognized increasingly as an important etiology of septic arthritis, osteomyelitis, and bacteremia, especially in young children. Colonization of the posterior pharynx is a key step in the pathogenesis ofK. kingaedisease. Previous work established that type IV pili are necessary forK. kingaeadherence to the respiratory epithelium. In this study, we set out to identify additional factors that influenceK. kingaeinteractions with human epithelial cells. We found that genetic disruption of the gene encoding a predicted trimeric autotransporter protein called Knh (KingellaNhhAhomolog) resulted in reduced adherence to human epithelial cells. In addition, we established thatK. kingaeelaborates a surface-associated polysaccharide capsule that requires a predicted ABC-type transporter export operon calledctrABCDfor surface presentation. Furthermore, we discovered that the presence of a surface capsule interferes with Knh-mediated adherence to human epithelial cells by nonpiliated organisms and that maximal adherence in the presence of a capsule requires the predicted type IV pilus retraction machinery, PilT/PilU. On the basis of the data presented here, we propose a novel adherence mechanism that allowsK. kingaeto adhere efficiently to human epithelial cells while remaining encapsulated and more resistant to immune clearance.IMPORTANCEKingella kingaeis a Gram-negative bacterium that is being recognized increasingly as a cause of joint and bone infections in young children. The pathogenesis of disease due toK. kingaebegins with bacterial colonization of the upper respiratory tract, and previous work established that surface hair-like fibers called type IV pili are necessary forK. kingaeadherence to respiratory epithelial cells. In this study, we set out to identify additional factors that influenceK. kingaeinteractions with respiratory epithelial cells. We discovered a novel surface protein called Knh that mediatesK. kingaeadherence and found that a surface-associated carbohydrate capsule interferes with the Knh-mediated adherence of organisms lacking pili. Further analysis revealed that pilus retraction is necessary for maximal Knh-mediated adherence in the presence of the capsule. Our results may lead to new strategies to prevent disease due toK. kingaeand potentially other pathogenic bacteria.

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