Evaluation of lipopolysaccharide and capsular polysaccharide as subunit vaccines against experimental melioidosis.
Burkholderia pseudomallei is the causative agent of melioidosis, which is a major cause of morbidity and mortality in endemic regions. Currently there is no human vaccine against melioidosis. In this study, LPS or capsular polysaccharide was used to immunize BALB/c mice. The different polysaccharide antigens induced antibody responses. Mice vaccinated with LPS developed predominantly IgM and IgG3 responses. Contrastingly, mice vaccinated with capsular polysaccharide developed a predominantly IgG2b response. After immunization, mice were challenged by the intra-peritoneal route and an increased mean time to death was observed compared with unvaccinated controls. Immunization with LPS provided an optimal protective response. Mice challenged by the aerosol route showed a small increase in the mean time to death compared with the unvaccinated controls. The passive transfer of antigen from immunized into naive mice provided protection against a subsequent challenge. This study is the first time antigens protective by active immunization have been identified and suggests that polysaccharides have potential as vaccine candidates against melioidosis.
Nelson
Michelle
M
Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, UK.
Prior
Joann L
JL
Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, UK.
Lever
M Stephen
MS
Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, UK.
Jones
Helen E
HE
Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, UK.
Atkins
Timothy P
TP
Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, UK.
Titball
Richard W
RW
Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, UK.
D000336:Aerosols; D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D016667:Bacterial Capsules / Q000008:administration & dosage / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology*; D016957:Burkholderia pseudomallei / Q000276:immunology*; D017358:Cell Wall Skeleton / Q000008:administration & dosage / Q000276:immunology; D003311:Cord Factors / Q000008:administration & dosage / Q000276:immunology; D005260:Female; D007116:Immunization, Passive; D007074:Immunoglobulin G / Q000096:biosynthesis; D007274:Injections, Intraperitoneal; D008050:Lipid A / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000276:immunology; D008070:Lipopolysaccharides / Q000008:administration & dosage / Q000276:immunology*; D008554:Melioidosis / Q000276:immunology / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C; D013047:Specific Pathogen-Free Organisms; D022223:Vaccines, Subunit / Q000276:immunology
D000336:Aerosols; D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D017358:Cell Wall Skeleton; D003311:Cord Factors; D007074:Immunoglobulin G; D008050:Lipid A; D008070:Lipopolysaccharides; C075897:Ribi adjuvant; D022223:Vaccines, Subunit