Protection in a mouse peritonitis model mediated by iron-regulated outer-membrane protein of Salmonella typhi coupled to its Vi antigen.
Vi polysaccharide and iron-regulated outer-membrane proteins (IROMPs) were extracted and purified from the standard strain of Salmonella typhi, Ty2. These were then conjugated by chemical coupling using the carbodimide method. Vi-IROMP conjugate was tested for its ability to protect against colonization by S. typhi in different organs. Mice immunized with 2.5 microg Vi-IROMP conjugate showed the most protection, as the least bacterial colonization of spleen, liver and Peyer's patches was observed. Peritoneal macrophages obtained from conjugate-treated mice phagocytosed bacteria efficiently. Circulating antibodies and the delayed type hypersensitivity response elucidated by mouse foot-pad swelling was significantly higher in conjugate-treated animals. These results clearly demonstrate that an IROMP and polysaccharide conjugate of S. typhi prepared from the same strain has the potential to protect animals against challenge.
Chibber
Sanjay
S
Department of Microbiology, Panjab University, Chandigarh, India.
Bhardwaj
Sonia B
SB
Department of Microbiology, Panjab University, Chandigarh, India.
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D000942:Antigens, Bacterial / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification; D015169:Colony Count, Microbial; D004195:Disease Models, Animal; D006968:Hypersensitivity, Delayed; D033862:Iron-Binding Proteins; D008099:Liver / Q000382:microbiology; D017737:Macrophages, Peritoneal / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D033902:Periplasmic Binding Proteins; D010538:Peritonitis / Q000276:immunology* / Q000382:microbiology; D010581:Peyer's Patches / Q000382:microbiology; D010587:Phagocytosis / Q000276:immunology; D011135:Polysaccharides, Bacterial / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification; D022562:Salmonella Vaccines / Q000276:immunology*; D012485:Salmonella typhi / Q000276:immunology* / Q000472:pathogenicity; D013154:Spleen / Q000382:microbiology; D014435:Typhoid Fever / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D014611:Vaccination; D018074:Vaccines, Conjugate / Q000276:immunology
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D033862:Iron-Binding Proteins; D033902:Periplasmic Binding Proteins; D011135:Polysaccharides, Bacterial; D022562:Salmonella Vaccines; D018074:Vaccines, Conjugate