Attachment of Moraxella catarrhalis occurs to the positively charged domains of pharyngeal epithelial cells

Ahmed, Kamruddin; Nakagawa, Tomomi; Nakano, Yamaji; Martinez, Glenda; Ichinose, Akitoyo; Zheng, Can Hong; Akaki, Mayumi; Aikawa, Masamichi; Nagatake, Tsuyoshi

doi:10.1006/mpat.1999.0342

Cited by 19 publications

(13 citation statements)

References 18 publications

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“…A likely reason for the observed effects of amination of PEG-collagen stems from the fact that both mammalian and bacterial cells in most cases have a negative net charge (Ahmed et al, 2000). Consequently, they tend to adhere better to positively charged surfaces (Jacobson and Ryan, 1982).…”

Section: Resultsmentioning

confidence: 98%

Improving biomaterial properties of collagen films by chemical modification

Tiller

Bonner

Pan

et al. 2001

Biotech & Bioengineering

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Films of bovine collagen were chemically modified with the goal of improving their biomaterial properties. The modified films were investigated with respect to their affinity to fibroblast and endothelial cells, as well as their antibacterial properties tested by adhesion of Staphylococcus aureus. Modifications that only change the net charge of collagen, such as acetylation, succinylation, and treatment with glutaraldehyde (all increase the negative charge), and amination with ethylenediamine (EDA), N,N-dimethyl-EDA (DMEDA), or butylamine (all increase the positive charge), did not dramatically alter the mammalian cell attachment to the film. In contrast, derivatization of collagen using methoxypoly(ethylene glycol) (PEG) diminished the attachment of fibroblasts by 98 +/- 1% and of endothelial cells by more than 99% compared to unmodified collagen. Moreover, the rate of growth of fibroblasts dropped by 97 +/- 1% and that of endothelial cells by 88 +/- 3% as a result of PEGylation of collagen. Adhesion of S. aureus cells also plummeted by 93 +/- 2% as a result of this PEGylation. With these antifouling properties, PEG-collagen may be a promising coating material for coronary stents. Subsequent derivatization of PEG-collagen with EDA or DMEDA abolished its mammalian cell-repelling ability, whereas bacterial cell repulsion was partially retained: for example, DMEDA-modified PEG-collagen exhibits up to a 5-fold lower bacterial adhesion than collagen. It is worth noting that a material that allows mammalian cell attachment but reduces bacterial adhesion could be useful as an implant or coating.

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Section: Resultsmentioning

confidence: 98%

Improving biomaterial properties of collagen films by chemical modification

Tiller

Bonner

Pan

et al. 2001

Biotech & Bioengineering

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“…A recent study by Ahmed et al (6) investigated the influence of charge on adherence. Although bacteria and epithelial cells are both negatively charged, interaction between the negatively charged surface of M. catarrhalis cells and positively charged domains called microplicea on pharyngeal epithelial cells was found.…”

Section: Adherencementioning

confidence: 99%

Moraxella catarrhalis: from Emerging to Established Pathogen

et al. 2002

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SUMMARY Moraxella catarrhalis (formerly known as Branhamella catarrhalis) has emerged as a significant bacterial pathogen of humans over the past two decades. During this period, microbiological and molecular diagnostic techniques have been developed and improved for M. catarrhalis, allowing the adequate determination and taxonomic positioning of this pathogen. Over the same period, studies have revealed its involvement in respiratory (e.g., sinusitis, otitis media, bronchitis, and pneumonia) and ocular infections in children and in laryngitis, bronchitis, and pneumonia in adults. The development of (molecular) epidemiological tools has enabled the national and international distribution of M. catarrhalis strains to be established, and has allowed the monitoring of nosocomial infections and the dynamics of carriage. Indeed, such monitoring has revealed an increasing number of Β-lactamase-positive M. catarrhalis isolates (now well above 90%), underscoring the pathogenic potential of this organism. Although a number of putative M. catarrhalis virulence factors have been identified and described in detail, their relationship to actual bacterial adhesion, invasion, complement resistance, etc. (and ultimately their role in infection and immunity), has been established in a only few cases. In the past 10 years, various animal models for the study of M. catarrhalis pathogenicity have been described, although not all of these models are equally suitable for the study of human infection. Techniques involving the molecular manipulation of M. catarrhalis genes and antigens are also advancing our knowledge of the host response to and pathogenesis of this bacterial species in humans, as well as providing insights into possible vaccine candidates. This review aims to outline our current knowledge of M. catarrhalis, an organism that has evolved from an emerging to a well-established human pathogen.

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“…However, another possibility also exists. The epitope recognized by MAb 8E7 may not be directly involved in adherence; instead, the MAb's effect on bacterial attachment may be due to steric hindrance (34) or charge shift (1). Further study, possibly with a deletion of LOS from the outer membrane of M. catarrhalis by gene mutation, will be needed to evaluate if LOS itself is an adhesin and to determine what role it plays in bacterial adherence.…”

Section: Effect Of Mab 8e7 On Bacterial Clearance From Mouse Lungsmentioning

confidence: 99%

Functional Characteristics of a Protective Monoclonal Antibody against Serotype A and C Lipooligosaccharides from Moraxella catarrhalis

Chen

McMichael³

et al. 2001

Infect Immun

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A monoclonal antibody (MAb), designated MAb 8E7 (immunoglobulin G3), specific for Moraxella catarrhalis lipooligosaccharide (LOS) was evaluated for its functional activity in vitro and in a mouse model of colonization. Enzyme-linked immunosorbent assay (ELISA) demonstrated that the MAb 8E7 could be prepared to a high titer against LOS of the homologous strain 035E, and that it had bactericidal activity. MAb 8E7 reacted with M. catarrhalis serotype A and C LOSs but not serotype B LOS, as measured by ELISA and Western blotting. On the basis of published structures of LOSs, this suggests that the epitope recognized by MAb 8E7 is directed to a common sequence of either ␣-GlcNAc-(132)-␤-Glc-(13 at the branch substituting position 4 of the trisubstituted Glc residue or a terminal tetrasaccharide ␣-Gal-(134)-␤-Gal-(134)-␣-Glc-(132)-␤-Glc-(13 at the branch substituting position 6 of the trisubstituted Glc residue. In a whole-cell ELISA, MAb 8E7 reacted with 70% of the 30 wild-type strains and clinical isolates tested. Immuno-electron microscopy demonstrated that MAb 8E7 reacted with a cell surface-exposed epitope of LOS on strain O35E. MAb 8E7 inhibited the adherence of strain O35E to Chang conjunctival epithelial cells by 90%. Passive immunization with MAb 8E7 could significantly enhance the clearance of strain O35E from mouse lungs in an aerosol challenge mouse model. This enhanced bacterial clearance was inhibited when MAb 8E7 was absorbed by M. catarrhalis serotype A LOS, indicating that the M. catarrhalis LOS-directed antibody may play a major role in the enhancement of M. catarrhalis clearance from lungs. These data suggest that MAb 8E7, which recognizes surface-exposed LOS of M. catarrhalis, is a protective antibody against M. catarrhalis.Moraxella catarrhalis is an important and common cause of otitis media in children as well as bronchopulmonary infection in the elderly, especially those with underlying pulmonary disease or a compromised immune system (4, 5, 26). Sporadic cases of conjunctivitis, meningitis, endocarditis, ophthalmia neonatorum, keratitis, urethritis, peritonitis, and septicemia have also been reported to be due to M. catarrhalis (25). In addition, an extremely high carriage rate (56%) has been reported for healthy children (11,12,18). Although the pathogenesis of M. catarrhalis infection is not fully understood, it is generally agreed that it has several virulence factors involved in colonization and adherence that enable it to evade the normal host defense mechanisms and that allow it to cause disease.The lipooligosaccharide (LOS) from M. catarrhalis is a major component of the outer membrane and is a potential virulence factor (7, 13). LOS consists of an oligosaccharide and lipid A and is similar to the lipopolysaccharide (LPS) of gramnegative enteric pathogens, but it lacks the O-antigenic side chain of repeating units characteristic of classical LPS. LOS has been demonstrated to be an important virulence factor for such gram-negative bacteria as Neisseria meningitidis, Neisseria gonorrhoeae...

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Attachment of Moraxella catarrhalis occurs to the positively charged domains of pharyngeal epithelial cells

Cited by 19 publications

References 18 publications

Improving biomaterial properties of collagen films by chemical modification

Improving biomaterial properties of collagen films by chemical modification

Moraxella catarrhalis: from Emerging to Established Pathogen

Functional Characteristics of a Protective Monoclonal Antibody against Serotype A and C Lipooligosaccharides from Moraxella catarrhalis

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