Evaluation of immunogenicity of iHPs derived from MHC homozygous iPSCs. (A) Schematic diagram for the assessment of alloimmune response to iPSC-derived iHPs. (B) Titration of serum from MCMs infused with MHC-mismatched peripheral blood lymphocytes (positive control). Day-0 serum before lymphocyte infusion. Day-90 serial dilutions of serum collected 90 days after infusion. nMFI values and fluorescence-activated cell sorting plots are shown. (C) Titration graphs of serum samples from each group collected at different time points from animals that were infused with MHC homozygous iHPs that were not activated with IFN-γ. (D) Titration graphs of serum samples from each group collected at different time points from animals that were infused with MHC homozygous iHPs that were activated with IFN-γ and analyzed. Dot plots of 1/20 and 1/40 dilutions of serum collected at different times after iHP infusion from representative animals are shown. In panels C and D titration graphs, each dot represents a different animal from each group. The different days of the serum collection after the first iHP infusion are indicated by different colors (day 0-120).