Fig. 9: Cellular responses towards SpA* and LukAB RARPR-33 in minipigs.
Minipig PBMCs were isolated pre- and post-immunization of animals immunized with 100 µg SpA* + 100 µg LukAB RARPR-33 adjuvanted with AS01B and frozen until use. To track vaccine-specific T cell responses, PBMCs were thawed, labelled with carboxifluorescein diacetate succinimidyl ester (CFSE) and ex vivo restimulated for 4 days in the presence of 8 µg/ml SpA* or LukAB RARPR-33. Subsequently, T-cell proliferation was tracked by CFSE dilution (A-C). The proliferation index represents the fold increase in CFSE dilution between stimulated and unstimulated cells of total T cells (CD3 + ) specific for A SpA*, B LukAB, C CD4 + T cells, CD8 + T cells, and CD4 + /CD8 + T cells specific for LukAB. D IFNγ and TNFα secreting cells from minipig PBMCs isolated after three immunizations with LukAB RARPR-33 + AS01B or AS01B alone was determined by ELISpot by direct ex vivo stimulation of the isolated fresh PBMCs with LukAB RARPR-33. Each point represents an individual animal and group mean ± SD is shown. AS01B Adjuvant System AS01B, IFN-γ interferon-gamma, LukAB leukocidin AB, SFU spot-forming units, SpA SpA Staphylococcal protein A, TNFα tumor necrosis factor alpha.
