Fig. 2: Conjoined P30 can effectively supplant the endogenous helper epitope within highly immunogenic neoantigen vaccines.
a IFNγ ELISpot: mice (n = 3) were immunized with poly(I:C) alone, Odc1MHC I, Odc1MHC I mixed with the P30 helper epitope, Odc1MHC I conjoined to the P30 helper epitope, or the Odc129mer SLP. Seven days later, the splenocyte response to Odc1MHC I was evaluated. One-way ANOVA with post hoc Tukey’s test. b Subcutaneous SMA560 tumor growth in mice (n = 7) following therapeutic immunization on days 1 and 8 with poly(I:C) alone, Odc1MHC I mixed with P30, Odc1MHC I conjoined to P30 (Odc1MHC I-P30), or the Odc129mer SLP. c IFNγ ELISpot: splenocyte response to Odc1MHC I 7 days following immunization with the Odc1MHC I-P30 SLP in the context of CD40L-blocking antibody or isotype control (n = 3). Isotype vs. αCD40L, two-sample t test. d IFNγ ELISpot: splenocyte response to the wild-type 29mer peptide assessed 7 days following immunization with the Odc129mer or Odc1MHC I-P30 SLP. The contribution of MHC II to the Odc1 wild-type response determined by immunologically blocking MHC II prior to peptide restimulation (n = 3). Isotype vs. αMHC II, two-sample t test. e IFNγ ELISpot: splenocyte response to the Lama4 or Alg8 MHC I-restricted neoepitope 7 days following immunization with the corresponding SLP in the context of CD40L-blocking antibody or isotype control (n = 3). Isotype vs. αCD40L, two-sample t test. f IFNγ ELISpot: for each neoantigen, mice (n = 3) were immunized with poly(I:C) alone, the MHC I-restricted neoepitope alone, the MHC I-restricted neoepitope mixed with the P30 helper epitope, the MHC I-restricted neoepitope conjoined to the P30 helper epitope, or the efficacious SLP spanning the endogenous neoantigen sequence (native long). Seven days later, the splenocyte response to the corresponding MHC I-restricted neoepitope was evaluated. One-way ANOVA with post hoc Tukey’s test. For tumor growth data, error bars = mean ± s.e.m.; for ELISpot data, errors bars = mean ± s.d.
