Cloning and surface expression of Pseudomonas aeruginosa O antigen in Escherichia coli.
As a step toward developing recombinant oral vaccines, we have explored the feasibility of expression of O polysaccharide antigens from Pseudomonas aeruginosa by Escherichia coli. We cloned in E. coli HB101 a 26.2-kilobase DNA fragment from P. aeruginosa strain PA103 that specifies the production of the O polysaccharide of Fisher immunotype 2 (IT-2) strains. The recombinant organism incorporated the P. aeruginosa IT-2 O polysaccharide onto the core of the E. coli lipopolysaccharide (LPS). Transfer of the recombinant plasmid to three LPS-rough strains of P. aeruginosa resulted in synthesis of IT-2 O antigen, and two of these transconjugant strains also synthesized a second O polysaccharide, presumably representing expression of a repressed, or an incomplete, set of genes for an endogenous O polysaccharide. Rabbits injected with the purified recombinant LPS made antibody specific for P. aeruginosa IT-2 O side chains, as did mice fed the recombinant E. coli strain. Expression of P. aeruginosa O antigens by enteric bacteria makes it possible to study these recombinant strains as oral vaccines to prevent P. aeruginosa infections.
D000818:Animals; D000917:Antibody Formation; D003001:Cloning, Molecular / Q000379:methods; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000235:genetics*; D005260:Female; D007070:Immunoglobulin A / Q000096:biosynthesis; D007074:Immunoglobulin G / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D051379:Mice; D019081:O Antigens; D010957:Plasmids; D011135:Polysaccharides, Bacterial / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000235:genetics* / Q000276:immunology
D004269:DNA, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D008070:Lipopolysaccharides; D019081:O Antigens; D011135:Polysaccharides, Bacterial