Synthetic Archaeosome Vaccines Containing Triglycosylarchaeols Can Provide Additive and Long-Lasting Immune Responses That Are Enhanced by Archaetidylserine
Figure 2
Antigen-specific CD8+ T cell activity in splenic cells of immunized mice as assayed by Elispot. Ratios of lipids in mol% for various compositions of archaeosomes were: di or triglycosylarchaeols/PGP (45/55), and gentiotriosyl-A/maltotriosyl-A/mannotriosyl-A/PGP (15/15/15/55), where “A” refers to archaeol. Trioses (1 : 1 : 1)/PGP refers to admixed triglycosyl-A/PGP vaccines, such that each contributed equal amounts of antigen. M. smithii represents OVA-loaded archaeosomes consisting of total polar lipids from M. smithii, as positive control. Mice were immunized subcutaneously at 0 and 3 weeks with OVA-loaded archaeosome adjuvants. Nonimmunized mice (naive) were included as negative controls. Spleens from duplicate mice were collected 5.5 weeks after first injection to determine the frequency (number of spots) of interferon-gamma (IFN-γ)-secreting splenic cells (spots) by enzyme-linked immunospot assay (Elispot). Omission of the major CD8 epitope of OVA (SIINFEKL) from the assay (no peptide control) was used to test for nonspecific responses. Means significantly different () were gentiotriosyl-A/PGP versus maltotriosyl-A/PGP (), mannotriosyl-A/PGP versus maltotriosyl-A/PGP (), and maltotriosyl-A/PGP versus PGP (). Those not significantly different were gentiotriosyl-A/PGP versus mannotriosyl-A/PGP (), gentiotriosyl-A/PGP versus gentiobiosyl-A/PGP (), mannotriosyl-A/PGP versus gentiobiosyl-A/PGP (), and gentiotriosyl-A/maltotriosyl-A/mannotriosyl-A/PGP versus M. smithii ().
