a review of an important human mucosal pathogen

Karalus, Richard J.; Campagnari, Anthony A.

doi:10.1016/s1286-4579(00)00314-2

Cited by 171 publications

(149 citation statements)

References 139 publications

Supporting

Mentioning

147

Contrasting

Unclassified

Order By: Relevance

“…Moraxella (Branhamella) catarrhalis is an important respiratory pathogen that frequently colonizes the upper respiratory tract (23)(24)(25), and accounts for one-third of all pediatric acute otitis media cases. However, this number will most likely rise because an increased nasopharyngeal colonization of M. catarrhalis has been suggested to follow in the wake of the use of a conjugated pneumococcal vaccine (26).…”

Section: H Ost Cells Express Various Pathogen Recognition Receptors (mentioning

confidence: 99%

Superantigen- and TLR-Dependent Activation of Tonsillar B Cells after Receptor-Mediated Endocytosis

Jendholm

Mörgelin

Vidakovics

et al. 2009

The Journal of Immunology

View full text Add to dashboard Cite

Classical B lymphocyte activation is dependent on BCR cross-linking in combination with physical interaction with Th cells. Other B cell molecules that contribute to the activation are complement, cytokine, and TLRs recognizing specific pathogen-associated molecular patterns. Moraxella (Branhamella) catarrhalis is a common Gram-negative respiratory pathogen that induces proliferation in human IgD-expressing B cells independently of T cell help. The activation is initiated by the B cell superantigen Moraxella IgD-binding protein (MID) through a nonimmune cross-linking of IgD. However, IgD cross-linking alone is not sufficient to induce proliferation. In this study, we characterized the significance of TLRs in superantigen-dependent B cell activation using whole bacteria or rMID in the presence or absence of TLR ligands. IgD cross-linking by MID sensitized B cells obtained from children with tonsillar hyperplasia for mainly TLR9, whereas TLRs 1, 2, 6, and 7 were less important. The Moraxella-induced activation was inhibited when a dominant-negative TLR9 ligand was added. Interestingly, BCR-mediated endocytosis of whole Moraxella and degradation of live bacteria in naive B cells were observed with fluorescence, confocal, and transmission electron microscopy. This unique observation proved the strong intracellular TLR9 response as well as highlighted the Ag-presenting function of B cells. In conclusion, our findings suggest an important role of TLRs in the adaptive immune response and reveal novel insights into the T cell-independent B cell activation induced by bacteria.

show abstract

Section: H Ost Cells Express Various Pathogen Recognition Receptors (mentioning

confidence: 99%

Superantigen- and TLR-Dependent Activation of Tonsillar B Cells after Receptor-Mediated Endocytosis

Jendholm

Mörgelin

Vidakovics

et al. 2009

The Journal of Immunology

View full text Add to dashboard Cite

show abstract

“…catarrhalis is an aerobic, gram-negative diplococcus that is an important respiratory tract pathogen in humans (15,26,34). M. catarrhalis annually causes 4 to 5 million of the total 25 million episodes of acute otitis media in the United States (27,33).…”

mentioning

confidence: 99%

Mining the Moraxella catarrhalis Genome: Identification of Potential Vaccine Antigens Expressed during Human Infection

Ruckdeschel¹,

Kirkham²,

Lesse

et al. 2008

Infect Immun

View full text Add to dashboard Cite

Moraxella catarrhalis is an important cause of respiratory infections in adults and otitis media in children.Developing an effective vaccine would reduce the morbidity, mortality, and costs associated with such infections. An unfinished genome sequence of a strain of M. catarrhalis available in the GenBank database was analyzed, and open reading frames predicted to encode potential vaccine candidates were identified. Three genes encoding proteins having molecular masses of approximately 22, 75, and 78 kDa (designated Msp [Moraxella surface proteins]) (msp22, msp75, and msp78, respectively) were determined to be conserved by competitive hybridization using a microarray, PCR, and sequencing of the genes in clinical isolates of M. catarrhalis. The genes were transcribed when M. catarrhalis was grown in vitro. These genes were amplified by PCR and cloned into Escherichia coli expression vectors. Recombinant proteins were generated and then studied using enzyme-linked immunosorbent assays with preacquisition and postclearance serum and sputum samples from 31 adults with chronic obstructive pulmonary disease (COPD) who acquired and cleared M. catarrhalis. New antibody responses to the three proteins were observed for a small proportion of the patients with COPD, indicating that these proteins were expressed during human infection. These studies indicate that the Msp22, Msp75, and Msp78 proteins, whose genes were discovered using genome mining, are highly conserved among strains, are expressed during human infection with M. catarrhalis, and represent potential vaccine antigens.

show abstract

“…At present, it is the third most frequent cause of otitis media and also a significant agent in sinusitis and lower respiratory tract infections in adults with pulmonary disease. M. catarrhalis is also one of the most common inhabitants of the pharynx of healthy children (1,2).…”

mentioning

confidence: 99%

Isolation and Characterization of a Novel IgD-Binding Protein fromMoraxella catarrhalis

Forsgren

Brant

Möllenkvist

et al. 2001

The Journal of Immunology

106

View full text Add to dashboard Cite

A novel surface protein of the bacterial species Moraxella catarrhalis that displays a high affinity for IgD (MID) was solubilized in Empigen and isolated by ion exchange chromatography and gel filtration. The apparent molecular mass of monomeric MID was estimated to ∼200 kDa by SDS-PAGE. The mid gene was cloned and expressed in Escherichia coli. The complete mid nucleotide gene sequence was determined, and the deduced amino acid sequence consists of 2123 residues. The sequence of MID has no similarity to other Ig-binding proteins and differs from all previously described outer membrane proteins of M. catarrhalis. MID was found to exhibit unique Ig-binding properties. Thus, in ELISA, dot blots, and Western blots, MID bound two purified IgD myeloma proteins, four IgD myeloma sera, and finally one IgD standard serum. No binding of MID was detected to IgG, IgM, IgA, or IgE myeloma proteins. MID also bound to the surface-expressed B cell receptor IgD, but not to other membrane molecules on human PBLs. This novel Ig-binding reagent promises to be of theoretical and practical interest in immunological research.

show abstract

a review of an important human mucosal pathogen

Cited by 171 publications

References 139 publications

Superantigen- and TLR-Dependent Activation of Tonsillar B Cells after Receptor-Mediated Endocytosis

Superantigen- and TLR-Dependent Activation of Tonsillar B Cells after Receptor-Mediated Endocytosis

Mining the Moraxella catarrhalis Genome: Identification of Potential Vaccine Antigens Expressed during Human Infection

Isolation and Characterization of a Novel IgD-Binding Protein fromMoraxella catarrhalis

Contact Info

Product

Resources

About