A large, antigenically conserved protein on the surface of Moraxella catarrhalis is a target for protective antibodies.
A monoclonal antibody (MAb) to Moraxella catarrhalis O35E bound to a surface-exposed epitope of a proteinaceous antigen of this organism. The antigen, designated UspA, was present in every strain of the pathogen tested in a colony blot RIA. UspA had a molecular mass on SDS-PAGE that varied between 300 and 400 kDa, depending on the individual M. catarrhalis strain. Passive immunization of mice with the UspA-reactive Mab enhanced pulmonary clearance of M. catarrhalis. Use of this Mab to screen a M. catarrhalis genomic DNA library permitted identification of a recombinant bacteriophage expressing the M. catarrhalis UspA protein. The recombinant UspA protein was used in Western blot analysis with sera from patients with M. catarrhalis pneumonia. Convalescent-phase sera but not acute-phase sera from these patients contained antibodies to this M. catarrhalis surface protein, indicating that M. catarrhalis strains growing in vivo express this molecule.
Helminen
M E
ME
Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235-9048.
Maciver
I
I
Latimer
J L
JL
Klesney-Tait
J
J
Cope
L D
LD
Paris
M
M
McCracken
G H
GH
Hansen
E J
EJ
D000328:Adult; D000818:Animals; D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial / Q000032:analysis / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis / Q000276:immunology*; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000032:analysis; D005260:Female; D015698:Genomic Library; D006801:Humans; D008168:Lung / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D001936:Moraxella catarrhalis / Q000276:immunology*; D016870:Neisseriaceae Infections / Q000276:immunology; D018410:Pneumonia, Bacterial / Q000276:immunology; D011863:Radioimmunoassay; D011994:Recombinant Proteins / Q000032:analysis / Q000276:immunology
D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D000939:Epitopes; D011994:Recombinant Proteins; C089675:UspA protein, Moraxella catarrhalis