The Moraxella catarrhalis porin-like outer membrane protein CD is an adhesin for human lung cells.
The outer membrane protein CD (OMPCD) of Moraxella catarrhalis is an outer membrane protein with several attributes of a potential vaccine antigen. We isolated four transposon mutants of strain O35E on the basis of their reduced binding to A549 human lung cells in microcolony formation assays, and we determined that they contain a transposon in ompCD. We also found that these transposon insertions had pleiotropic effects: mutants grew slower, became serum sensitive, bound approximately 10-fold less to A549 cells, and appeared transparent when grown on solid medium. We confirmed that these various phenotypes could be attributed solely to disruption of ompCD by constructing the isogenic strain O35E.CD1. O35E-ompCD was cloned, and recombinant Escherichia coli bacteria expressing the gene product exhibited a 10-fold increase in adherence to A549 cells. This is the first report of M. catarrhalis ompCD mutants, and our findings demonstrate that this gene product is an adhesin for human lung cells.
Holm
Melissa M
MM
Department of Microbiology and Immunology, Medical College of Ohio, Toledo, Ohio 43614-5806, USA.
Vanlerberg
Serena L
SL
Foley
Ian M
IM
Sledjeski
Darren D
DD
Lafontaine
Eric R
ER
D018829:Adhesins, Bacterial / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D001422:Bacterial Adhesion; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D003470:Culture Media; D004251:DNA Transposable Elements; D004847:Epithelial Cells / Q000382:microbiology; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D006801:Humans; D008168:Lung / Q000166:cytology / Q000382:microbiology*; D008969:Molecular Sequence Data; D001936:Moraxella catarrhalis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D016254:Mutagenesis, Insertional; D009154:Mutation
D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; C090131:CD protein, Branhamella; D003470:Culture Media; D004251:DNA Transposable Elements; C484698:outer membrane protein CD, Moraxella catarrhalis