title: Human neutrophil response to recombinant neisserial Opa proteins.
abstract: Interactions of human neutrophils with recombinant Escherichia coli expressing gonococcal outer membrane Opa proteins were examined using chemiluminescent and biological assays. Seven opa loci from Neisseria gonorrhoeae MS11 4.8 were expressed as beta-lactamase-Opa fusion proteins that contained all but the mature N-terminal amino acid of the full-length Opa protein fused to three N-terminal amino acids derived from the mature beta-lactamase. The Opa fusion proteins were exported and assembled in the outer membrane of E. coli in a manner similar to that of Opa in N. gonorrhoeae, as evaluated by antibody binding and in situ proteolytic cleavage. All fusion proteins exhibited the characteristic heat-modifiable migration in SDS-polyacrylamide gel electrophoresis that typifies Opa proteins of neisseriae. Opa fusion proteins conferred on E. coli the ability to stimulate a chemiluminescent response from human neutrophils in the absence of antibody or complement. The nature of the response in terms of chemiluminescence, phagocytosis, and killing was in all cases analogous to that seen using N. gonorrhoeae expressing the equivalent Opa protein. Neither E. coli nor gonococci expressing OpaA elicited a response from neutrophils. Use of E. coli expressing Opa fusions should be useful in defining their biological activities and pathogenic roles.
authors.affiliation: Laboratory of Microbial Structure and Function, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana 59840.
authors.forename: R J
authors.initials: RJ
authors.lastname: Belland
authors.forename: T
authors.initials: T
authors.lastname: Chen
authors.forename: J
authors.initials: J
authors.lastname: Swanson
authors.forename: S H
authors.initials: SH
authors.lastname: Fischer
mesh_terms: D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D001483:Base Sequence; D004926:Escherichia coli; D006801:Humans; D008163:Luminescent Measurements; D008969:Molecular Sequence Data; D009344:Neisseria gonorrhoeae; D009504:Neutrophils / Q000276:immunology* / Q000378:metabolism; D010587:Phagocytosis; D011993:Recombinant Fusion Proteins / Q000276:immunology
chemical_list: D001425:Bacterial Outer Membrane Proteins; D011993:Recombinant Fusion Proteins