The immunodominant peptide from listeriolysin in Quil A liposomes vaccinates CD8+ cytolytic T cells and confers protection to infection.

Cytolytic T-cell vaccination with immunodominant MHC class I-restricted peptides contained within Quil A liposomes has been previously demonstrated. In recent years, Quil A has been under consideration for use as an adjuvant in humans. We assessed the possible use of peptide inoculation in the context of Quil A liposomes to be protective in a mouse model. Listeria monocytogenes was used as the challenge pathogen and the previously identified listeriolysin 91-99 peptide as the immunogen. The listeriolysin 91-99 Quil A liposome inoculum showed significant enhancement of survival after challenge with up to 10 times the L. monocytogenes LD50.