scholarly journals Immunoglobulin G antibodies directed against protein III block killing of serum-resistant Neisseria gonorrhoeae by immune serum.

1986 ◽  
Vol 164 (5) ◽  
pp. 1735-1748 ◽  
Author(s):  
P A Rice ◽  
H E Vayo ◽  
M R Tam ◽  
M S Blake
Keyword(s):  
Membrane Protein ◽  
Neisseria Gonorrhoeae ◽  
Human Serum ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Immune Serum ◽  
Igg Antibodies ◽  
Porin Protein ◽  
Blocking Activity ◽  
Normal Human

Neisseria gonorrhoeae that resist complement-dependent killing by normal human serum (NHS) are sometimes killed by immune convalescent serum from patients recovering from disseminated gonococcal infection (DGI). In these studies, killing by immune serum was prevented or blocked by IgG isolated from NHS. Purified human IgG antibodies directed against gonococcal protein III, an antigenically conserved outer membrane protein, contained most of the blocking activity in IgG. Antibodies specific for gonococcal porin (protein I), the major outer membrane protein, displayed no blocking function. In separate experiments, immune convalescent DGI serum which did not exhibit bactericidal activity was restored to killing by selective depletion of protein III antibodies by immunoabsorption. These studies indicate that protein III antibodies in normal and immune human serum play a role in serum resistance of N. gonorrhoeae.

scholarly journals Expression of AniA, the Major Anaerobically Induced Outer Membrane Protein of Neisseria gonorrhoeae, Provides Protection against Killing by Normal Human Sera

2000 ◽  
Vol 68 (7) ◽  
pp. 4368-4369 ◽  
Author(s):  
J. A. Cardinale ◽  
V. L. Clark
Keyword(s):  
Membrane Protein ◽  
Neisseria Gonorrhoeae ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Elevated Serum ◽  
Serum Resistance ◽  
Aerobic Conditions ◽  
Acetylneuraminic Acid ◽  
Human Sera ◽  
Normal Human

ABSTRACT Anaerobically grown Neisseria gonorrhoeae has previously been shown to have elevated serum resistance in the absence of exogenous CMP-N-acetylneuraminic acid or detectable sialylation. We hypothesized that the anaerobically induced gonococcal outer membrane protein AniA might have a role in this phenomenon, as it is the only known gonococcal protein that is absent under aerobic conditions. An N. gonorrhoeae F62 derivative, RUG7035, in which aniA is under control of the tacpromoter, was used to examine the effect of AniA expression on serum resistance. In this study, we found that expression of AniA enhanced the serum resistance of N. gonorrhoeae and may account for these earlier observations.

Acid stress upregulated outer membrane proteins in clinical isolates ofNeisseria gonorrhoeae, but not most commensalNeisseria

2001 ◽  
Vol 47 (9) ◽  
pp. 871-876 ◽  
Author(s):  
R K Pettit ◽  
T M Whelan ◽  
K S Woo
Keyword(s):  
Membrane Proteins ◽  
Membrane Protein ◽  
Neisseria Gonorrhoeae ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Outer Membrane Proteins ◽  
Acid Stress ◽  
Immune Serum ◽  
Gonococcal Infection ◽  
Membrane Components

Human immune serum recognition of outer membrane components from commensal and pathogenic Neisseria cultured under neutral and acidic conditions was investigated. Acid stress caused no detectable alterations in lipooligosaccharide migration and (or) staining, in outer membrane protein profiles, or in immune serum recognition of outer membrane components from Neisseria mucosa or Neisseria sicca. There was also no difference in the lipoologosaccharide electrophoretic pattern of acid- and neutral-grown Neisseria lactamica, but there were differences in outer membrane protein expression. The outer membrane protein alterations induced by acid stress in N. lactamica were not the same as those seen in isolates from patients with uncomplicated gonococcal infection, pelvic inflammatory disease, and disseminated gonococcal infection. Many differences were detected in the immune serum recognition of outer membrane components from acid- and neutral-cultured N. lactamica and from the clinical isolates of Neisseria gonorrhoeae, and these should be considered in vaccine design.Key words: Neisseria gonorrhoeae, commensal Neisseria, acid stress, outer membrane proteins.

scholarly journals Antigenic Structure of Outer Membrane Protein E ofMoraxella catarrhalis and Construction and Characterization of Mutants

2000 ◽  
Vol 68 (11) ◽  
pp. 6250-6256 ◽  
Author(s):  
Timothy F. Murphy ◽  
Aimee L. Brauer ◽  
Norine Yuskiw ◽  
Thomas J. Hiltke
Keyword(s):  
Monoclonal Antibodies ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Vaccine Antigen ◽  
Antigenic Structure ◽  
Effective Vaccine ◽  
Fusion Peptides ◽  
Bacterial Surface ◽  
Normal Human

ABSTRACT Outer membrane protein E (OMP E) is a 50-kDa protein ofMoraxella catarrhalis which possesses several characteristics indicating that the protein will be an effective vaccine antigen. To study the antigenic structure of OMP E, eight monoclonal antibodies were developed and characterized. Three of the antibodies recognized epitopes which are present on the bacterial surface. Fusion peptides corresponding to overlapping regions of OMP E were constructed, and immunoblot assays were performed to localize the areas of the molecule bound by the monoclonal antibodies. These studies identified a surface-exposed epitope in the region of amino acids 80 through 180. To further study the protein, two mutants which lack OMP E were constructed. In bactericidal assays, the mutants were more readily killed by normal human serum compared to the isogenic parent strains. These results indicate that OMP E is involved in the expression of serum resistance of M. catarrhalis.

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