Biomedical subjects

G B Pier

Publications and source records attributed to G B Pier.

150 records · Page 9Linked to original sources

PubMedDate not supplied

Polysaccharide antigens of Pseudomonas aeruginosa.

Cell-surface polysaccharide antigens of Pseudomonas aeruginosa are important determinants of pathogenicity and represent target antigens for the development of vaccines. Two major and distinct cell-surface polysaccharides are expressed by different strains of P. aeruginosa: the serotype determinant located on the O polysaccharide side chain of the lipopolysaccharide and mucoid exopolysaccharide (MEP), an antigen usually made by isolates of P. aeruginosa from patients with cystic fibrosis. The serotype determinant has been isolated in a high-molecular-weight, non-toxic, immunogenic form known as high-molecular-weight polysaccharide. High-molecular-weight polysaccharide is safe and immunogenic in humans and elicits T cell immunity to P. aeruginosa infection in animals. Purified MEP antigen has been shown to be immunogenic in animals, and patients with cystic fibrosis colonized with mucoid P. aeruginosa respond to MEP with the production of high-titered serum antibody. In spite of brisk immune responses of patients with cystic fibrosis to MEP, they are unable to deal with the chronic respiratory colonization by mucoid P. aeruginosa. An association has been established between the presence of opsonic-killing antibody to MEP and the lack of colonization of older patients with cystic fibrosis with P. aeruginosa.

Antibodies, Bacterial↗

PubMedDate not supplied

Efficacy of cell wall Pseudomonas aeruginosa vaccines for protection against experimental pneumonia.

Three cell wall-derived Pseudomonas aeruginosa vaccines were evaluated for their capacity to provide protection from experimental pseudomonas pneumonia in guinea pigs. Two vaccines, Pseudogen, a heptavalent lipopolysaccharide vaccine, and PEV-01, a polyvalent glycine-EDTA cell wall extract, each produced hemagglutinating, opsonic, and serum bactericidal antibodies in guinea pigs. Significant protection from fatal hemorrhagic pneumonia was conferred by vaccination with these products. Purified, high-molecular weight polysaccharide vaccine was a less potent immunogen in guinea pigs and provided less protection from pneumonia. Protection from fatal pneumonia in vaccinees correlated with more rapid clearance of viable P. aeruginosa from lung tissue during the first 6 hr of infection. It appears that active immunization with certain cell wall-derived pseudomonas antigens can provide protection against experimental pseudomonas pneumonia.

Animals↗

PubMedDate not supplied

Immunochemistry of Pseudomonas aeruginosa lipopolysaccharides and high-molecular-weight polysaccharides.

A comparison was made of the immunochemical properties of high-molecular-weight polysaccharide (PS) and lipopolysaccharides (LPS) from Pseudomonas aeruginosa immunotype 1 and 2 (IT-1 and IT-2) strains. High-molecular-weight PS was found to be an immunogenic, nontoxic form of the LPS serotype determinant found on the O side chain of the LPS. PS and O side chains were serologically identical. Immunization of animals with either whole bacterial cells or purified PS or LPS resulted in comparable levels of antibody directed at PS or O side chains. Chemical analysis of PS and LPS indicated the presence of monosaccharides in PS preparations that are not present in LPS, while PS and LPS share other monosaccharides. PS also lacks core-type sugars found in LPS such as 2-keto-3-deoxyoctulosonic acid, heptose, and glucosamine. PS from IT-1 P. aeruginosa is immunogenic in humans, with essentially no toxicity noted.

Adult↗

PubMedDate not supplied

Immunologic basis for mouse protection provided by high-molecular-weight polysaccharide from immunotype 1 Pseudomonas aeruginosa.

Antibody responses were assayed in inbred strains of mice immunized with a high-molecular-weight polysaccharide (IT-1 PS) isolated from Fisher immunotype 1 Pseudomonas aeruginosa (P. aeruginosa 1). C3H/ANF mice generated the greatest antibody response after immunization with 1 microgram of antigen and could then survive challenge with 5 LD100 of P. aeruginosa 1 organisms. BALB/c mice produced lower levels of antibody and did so only after immunization with 50 micrograms of IT-1 PS. These mice could only withstand challenge with 1 LD100 of P. aeruginosa 1. The specificity of the antibody produced by these two strains differed. Antibody produced in C3H/ANF mice after primary immunization with either 1 microgram or 50 micrograms of IT-1 PS did not cross-react with other immunotypes of P. aeruginosa. Antibody produced in BALB/c mice after a primary immunization with 50 micrograms of IT-1 PS cross-reacted with polysaccharide isolated from Fisher immunotype 2 P. aeruginosa. These data indicate that, even within the same species, antibody responses to immunization with P. aeruginosa IT-1 PS may be qualitatively different. This kind of variation in immune response patterns will have to be considered in developing optimal regimens for immunization in human vaccine trials.

Animals↗

PubMedDate not supplied

Active and passive immunization strategies for Pseudomonas aeruginosa pneumonia.

The unusually high mortality associated with Pseudomonas aeruginosa pneumonia has provided an incentive for the development of immunologic strategies for preventing or treating this infection. A guinea pig model of experimental P. aeruginosa pneumonia was employed to determine prophylactic efficacy of active immunization with a detoxified lipopolysaccharide vaccine; efficacy of passive immune therapy utilizing a new hyperimmune immunoglobulin G preparation enriched for antibodies to P. aeruginosa immunotypes 1, 2, 4, and 6; and efficacy of active and passive immunization against the mucoid exopolysaccharide antigen associated with mucoid strains of P. aeruginosa. Each of these immunologic methods provided an element of protection against P. aeruginosa pneumonia.

Animals↗

PubMedDate not supplied

[The study of the reaction of terminated oligomerization in the synthesis of oligo-(beta1-6)-glucosamines].

The applicability of terminated oligomerization to the synthesis of oligo-(beta1-6)-glycosamines, fragments of the intercellular polysaccharide adhesin of staphylococci, was studied. The reactions of terminated oligomerization were carried out with mono-, di-, and trisaccharide monomers and N-protected aminopropanol; and spacered mono- and disaccharides as terminating molecules were also attempted. The primary formation of cyclic products of monomer intramolecular glycosylation was observed in almost all the reactions. Only the experiments with the monomer based on the disaccharide bromide under the conditions of the Helferich reaction led to reduced yields (30%) of the cyclic products. However, even in this case, the desired terminated oligosaccharides were generated in approximately 10% yield and mainly were the products of single glycosylation of the terminator by the monomer. These experiments allow the conclusion that, under the examined conditions, the reaction of terminated oligomerization could not result in the synthesis of oligoglucosamines with a high molecular mass.

Carbohydrate Sequence↗