Schematic representation of P. acnes- and PS-treatment protocols and gates strategy. F1 BALB/c x A/J mice were subcutaneously injected with P. acnes or PS once a week, during 3 weeks. Heat-coagulated hen’s egg white (HEW) was implanted concomitantly to the last P. acnes or PS dose in Protocol 1 (a) or 1 week after the third dose in Protocol 2 (b). For each protocol, the respective control group was treated with 350 μL of sterile commercial 0.9% saline, at the same conditions. Spleen cells were analyzed 14 days after HEW implantation. (c) Gates strategy used for flow cytometry analysis.