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L M Wetzler

Publications and source records attributed to L M Wetzler.

7 recordsLinked to original sources
PubMed1992

Gonococcal porin vaccine evaluation: comparison of Por proteosomes, liposomes, and blebs isolated from rmp deletion mutants.

The gonococcal major outer membrane protein, Por (protein I), is a potential vaccine candidate. A large-scale animal trial compared the immunogenicity of Por inserted in liposomes (mimicking its in vivo structure) with previously used vaccines containing Por. Por was purified from Rmp (protein III)-negative gonococcal mutants and made into five different formulations: proteosomes, proteosomes absorbed to alum, liposomes, gonococcal membrane blebs, and gonococcal membrane blebs absorbed to alum. Por liposomes induced the greatest amount of Por antibodies; proteosomes and both preparations of blebs induced minimal amounts of Por antibodies. Proteosomes absorbed to alum induced slightly lower amounts of Por antibodies than did liposomes, especially when protein IA was used. Whole-organism absorption studies revealed that a significantly greater percentage of liposome-induced Por antibodies recognized exposed portions of the protein than did proteosome- or proteosome/alum-induced antibodies.

Adjuvants, Immunologic↗
PubMed1992

Gonococcal lipooligosaccharide sialylation prevents complement-dependent killing by immune sera.

Previous investigators have demonstrated that a sialic acid residue is added to the terminal galactose moiety of gonococcal lipooligosaccharide (LOS) when incubated with 5'-CMP-N-acetylneuraminic acid. When this in vitro sialylation occurs, gonococci become resistant to the bactericidal activity of normal human serum. This is believed to result because the added sialic acid residue blocks the binding of bactericidal anti-LOS antibodies present in normal human serum. We extend these studies by demonstrating that sialylated gonococci also become resistant to the bactericidal effect of immune sera containing antibodies that recognize exposed components of the outer membrane besides LOS. Prevention of antibody binding to the organism was not the cause, since the same percentage of bactericidal antibodies to the major outer membrane protein, Protein I, can be absorbed with sialylated organisms as with wild-type organisms. In addition, gonococcal sialylation prevents opsonophagocytosis by antigonococcal antisera. The negative effect of sialic acid on the complement pathway might be the reason for the findings in this study.

Antigens, Bacterial↗
PubMed1989

The construction and characterization of Neisseria gonorrhoeae lacking protein III in its outer membrane.

Protein III (PIII) is a highly conserved, antigenically stable gonococcal outer membrane protein that is closely associated with the major outer membrane protein, protein I (PI). We have previously reported the cloning of the PIII gene. This gene was inserted into the Eco RI site of the runaway plasmid pMOB45. The beta-lactamase (beta la) Bam HI restriction fragment from the gonococcal plasmid pFA3 was inserted at the Xba I site in the PIII gene. The plasmid construct was Hae III methylated and the PIII/beta la insert was excised with Eco RI and used to transform gonococcal strain F62. One beta la+, ampicillin-resistant transformant was isolated and designated 2D. A Western blot of 2D whole cell lysate was probed with affinity-purified polyclonal PIII antisera. No PIII reactivity was detected. Southern blot analysis was performed on F62 and 2D chromosomal DNA that were cut with Eco RI or Cla I. A PIII DNA probe hybridized with fragments 2.2 kb larger in strain 2D than strain F62. This corresponds to the size of the beta la insert. A beta la-specific probe hybridized with the same 2D restriction fragments as above, but did not react with any F62 fragments, confirming that homologous recombination had occurred. There were minimal phenotypic changes between 2D and its parent strain, F62. Chromosomal DNA from 2D was able to transform gonococcal strains F62, UU1, and Pgh 3-2, rendering these PIII-. 2D and other PIII- transformants can now be used to study the role of PIII in gonococcal physiology, metabolism, membrane structure, and pathogenesis. Moreover, we now have organisms from which we can purify gonococcal proteins without PIII contamination.

Ampicillin Resistance↗
PubMed1988

Characterization and specificity of antibodies to protein I of Neisseria gonorrhoeae produced by injection with various protein I-adjuvant preparations.

A major goal of gonococcal research is the development of a gonorrheal vaccine. A vaccine candidate is the major outer membrane protein (PI) of the gonococcus, which has limited antigenic variability. Two main subtypes, PIA and PIB, and nine main serotypes have been described. To avoid raising anti-protein III (PIII)-blocking antibodies and limit potential lipooligosaccharide toxicity, PI was chromatographically isolated with minimal PIII contamination (less than 1%) from Pgh 3-2 (PIB), a serum-sensitive gonococcal strain and UU1 (PIA), a serum-resistant gonococcal strain. Alum was used as an adjuvant and the antibodies raised in rabbits did not agglutinate the organisms, were not opsonic, and bactericidal titers were not increased. To present PI in a form mimicking its in vivo disposition, it was inserted into liposomes. The resulting antisera did agglutinate the organism and contained opsonic and bactericidal activity greater than the preimmune sera or alum-generated sera. The PIB liposome antisera also had higher ELISA titers to a synthetic peptide equivalent to an exposed portion of PIB and a higher percentage of antibodies absorbed by whole organisms than the PIB alum antisera. We speculate that when PI is presented in liposomes, the antibodies raised are mainly to surface-exposed epitopes of the protein as opposed to when PI is presented absorbed to alum, where the antibodies are produced mainly to buried epitopes.

Adjuvants, Immunologic↗