Fig. 4

Breakage of self-tolerance. IgG autoantibody responses measured by standard ELISA. a, b C57BL/6 mice (n = 10 per group) were immunized with a PD-L1 (a) or CTLA-4 (b) SpyCatcher-VLP vaccine (filled circles) or with a control vaccine (n = 3 per group) consisting of similar amounts of spy-antigen mixed with untagged AP205 VLPs (open squares). Both vaccines were formulated using aluminum hydroxide adjuvant (Statens Serum Institut, Copenhagen, Denmark). Mice were immunized with a dose of 5 µg antigen on days 0, 21 and 42 and serum was collected on day 56 after first immunization. Median endpoint titers were compared for the PD-L1 vaccination groups (P = 0.01) and the CTLA-4 vaccination groups (P = 0.01) using Mann–Whitney Rank Sum test. c, d BALB/c mice (n = 4) were immunized with an IL-5 SpyTag-VLP vaccine or a control vaccine (soluble IL-5 + untagged AP205 VLP) (n = 5) which were both formulated with aluminum hydroxide (Statens Serum Institut, Copenhagen, Denmark). Mice were immunized on days 0, 21 and 42 with antigen doses of 5, 2.5 and 2.5 µg, respectively, and serum was collected on days 56 (c) and 112 (d). Median endpoint titers for the two vaccination groups were compared using Mann–Whitney Rank Sum test; day 56 (P = 0.2) and day 122 (P = 0.2)