Montanide ISA 71 VG is Advantageous to Freund's Adjuvant in Immunization Against S. aureus Infection of Mice

The enormous capacity of Staphylococcus aureus to acquire antibiotic resistance makes it a permanent task to search for and to develop new anti-infectives. One of the possible approaches is the early active immunization of risk patients and animal stocks to prevent S.aureus infections. Based on a S.aureus proteome screen with S.aureus-specific human antiserum, we have previously identified several anchorless cell wall proteins to be used as novel vaccine candidates. To develop an efficient anti-S.aureus vaccine, the supplemented adjuvants Montanide ISA 71 VG and ISA 206 were compared to Freund's adjuvant in terms of handling, induction of cytokine profile, triggering antigen-specific immunoglobulin production of different IgG subclasses and provision of increased survival rates in our S.aureus sepsis mouse model. Immunization with ISA 71 VG in comparison with Freund's adjuvant induced slightly delayed but comparably strong increase of antigen-specific antibody titres and conferred protective effect against S.aureus challenge. In contrast using ISA 206 as adjuvant, significantly lower IgG titres and consequently, no protective effect against S.aureus infection were observed. Handling and tolerability of the Montanide is superior to Freund's adjuvant. Montanide ISA 71 VG can serve as an effective adjuvant replacement for Freund's adjuvant in research with a prospective usage in animal and human vaccines against bacterial pathogens.