McArthur, JSchulze, KChin, JCurrie, B JSriprakash, K STalay, S RChhatwal, G SGuzmán, C AWalker, M J2004-05-032009-05-272004-05-032009-05-272004-05-03McArthur J, Schulze K, Chin J, Currie BJ, Sriprakash KS, Talay SR, Chhatwal GS, Guzmán CA, Walker MJ. Immune responses of a liposome/ISCOM vaccine adjuvant against streptococcal fibronectin binding protein 1 (Sfb1) in mice. Indian Journal of Medical Research. 2004 May; 119 Suppl(): 115-20http://imsear.searo.who.int/handle/123456789/20499BACKGROUND & OBJECTIVES: The fibronectin binding protein Sfb1 of Streptococcus pyogenes is a well characterised antigen which induces protection against lethal challenge with group A streptococcus (GAS) when adjuvanted with cholera toxin B-subunit (CTB). As an alternative to CTB adjuvanted intranasal immunisations we investigated the immune responses generated in mice using Sfb1 incorporated in to the skin and mucosal adjuvant SAMA4. METHODS: Mice (BALB/c) were vaccinated intradermally with 100 microl of either SAMA4 (adjuvant only group) or SAMA4/Sfb1 and were boosted 7 days later. Mice vaccinated with CTB based vaccines were immunised by intranasal inoculation with a mixture containing 30 microg Sfb1 and 10 microg CTB on days 1, 3, 5 and 15. At 14 days after the last booster immunisation the immune response was characterised and mice were challenged with 10(8) CFU of S. pyogenes. RESULTS: Mice vaccinated with SAMA4/Sfb1 elicited a Sfb1-specific IgG response in the sera that was significantly higher than that seen in control mice and mice immunised with the adjuvant only (P<0.05). No significant differences were seen for specific IgA antibodies in the sera in all groups examined. Compared with non-immunised and adjuvant only immunised controls, mice immunised with the Sfb1/SAMA4 vaccine exhibited a significant increase (P<0.05) in the number of Sfb1 reactive spleen cells in lymphoproliferation assays which were three fold higher than those seen for mice vaccinated with the Sfb1/CTB vaccine. Mice vaccinated with CTB/Sfb1 had the highest level of protection (80%) as where mice vaccinated with SAMA4 and SAMA4/Sfb1 displayed no protection (20% and 40%). INTERPRETATION & CONCLUSION: These data suggest that the SAMA4 adjuvant used in this study fails to elicit protective immunity in BALB/c mice when used to adjuvant the known protective antigen Sfb1.engAdhesins, Bacterial --immunologyAnimalsAntibody FormationBacterial Vaccines --immunologyEnzyme-Linked Immunosorbent AssayISCOMsLiposomesLymphocytes --immunologyMiceMice, Inbred BALB CStreptococcus pyogenes --immunologyJournal Article