Figure 7: Spi6 protects of CD8α DC from the kiss of death from GrB. In wild-type mice presentation of pMHC and costimulation by CD8α DC stimulate the expansion of cognate CTL. Cognate CD8α DCs are protected from killing by CTL GrB through inhibition by Spi6. In Spi6 KO mice, GrB is not inhibited and so the killing of CD8α DC impairs the expansion of CTL. This model is for both the recognition of CD8α DC by primary CTL and secondary (memory) CTL.