Immunological studies on soluble protective antigen (SPA) separated from culture supernatant fluids of Salmonella enteritidis.
Studies were carried out to analyze the antigenicity of Soluble Protective Antigen (SPA) separated from culture supernatant fluids of Salmonella enteritidis strain 2547. Mice injected with anti-SPA mouse serum were capable of tolerating a challenge dose of 100 LD50 S. enteritidis. After absorption of the anti-SPA mouse serum with lipopolysaccharide (LPS) prepared from strain 2547, no protective effect was observed. Ouchterlony immunodiffusion analysis showed that the P1 fraction obtained from Sephadex G-50 gel filtration of strain 2547 or 2822 LPS reacted with antiserum to SPA, but no reaction was observed with the P2 or P3 fraction. The LPS from strain 2547 gave 80% mouse protection against challenge with 100 LD50 of the homologous bacteria, while the P1 from strain 2547 LPS afforded 40% protective immunity. When P1, LPS and SPA were transferred into the footpad of SPA-immunized mice, a positive delayed footpad reaction was elicited. Similarly, macrophage migration inhibitory activity was observed when SPA-induced peritoneal exudate cells were cultured in medium containing P1, LPS and SPA. These results suggest that the antigenic determinant of SPA exists in the O-antigenic components of LPS.
Uchiya
K
K
Department of Microbiology, Faculty of Pharmacy, Meijo University Tenpaku-ku Nagoya, Japan.
Sugihara
H
H
D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology* / Q000302:isolation & purification; D003470:Culture Media / Q000032:analysis; D005260:Female; D051379:Mice; D008815:Mice, Inbred Strains; D012481:Salmonella Infections, Animal / Q000276:immunology / Q000517:prevention & control; D012477:Salmonella enteritidis / Q000276:immunology*; D012995:Solubility
D000942:Antigens, Bacterial; D003470:Culture Media