Figure 4.

Cytotoxic capacities of MiHA specific CD4 T-cells. Cell lysis calculated after measurement of target cell survival using flowcytometric cell counting after 24 h of incubation with the MiHA specific CD4 T-cells in an effector to target ratio of 10:1. Target cells were patient EBV-LCL and effector cells were MiHA specific CD4 T-cells. CD4 T-cells with irrelevant specificity were used as negative controls. EBV-LCL from patient A, B, C and D are represented by black, dark gray, light gray, and blocked bars, respectively. For all MiHA, individual MiHA specific CD4 T-cell clones were identified that exerted cytotoxic activity against EBV-LCL, resulting in 19–51% specific lysis, although not all differences of the mean lysis by MiHA specific CD4 T-cell clones with background lysis were statistically significant (Mann-Whitney U-test) due to low number of experiments.