Figure 5
Ionotropic glutamate receptor blockers NBQX and MK801 do not impact antigen-dependent CD8 + T cell mediated killing of murine lymphoma cells. (A, B) Impact of ionotropic glutamate receptor blockers MK801 (10 μM) and NBQX (30 μM) on the killing behavior of activated OT-I T cells using murine EL-4 lymphoma cells loaded with ovalbumin (OVA)- peptide257-264 (SIINFEKL; 1 nM) as target cells (effector-to-target cell ratio 1:1). The amount of ATP in the supernatant following cell lysis was assessed as a parameter of target cell viability. (A ) Supernatant ATP levels determined from 0, 50,000 and 100,000 EL-4 cells and activated OT-I T cells cultured separately for six hours demonstrate a linear dependence on the number of cultured cells (n = 3 mice, experiments performed in triplicates). (B ) In the absence of OVA-peptide257-264 loading of EL-4 cells (EL4), supernatant ATP levels upon co-culture with activated OT-I T cells (OT-I) were approximately the sum of those obtained by separate culture of both cell types (EL-4 + OT-I-OVA). OVA-peptide257-264 loading of EL-4 cells significantly reduced supernatant ATP levels upon co-culture with activated OT-I T cells (EL-4 + OT-I + OVA) for six hours. MK801 and NBQX had no impact on the killing efficacy (EL-4 + OT-I + OVA + MK801/NBQX; n = 3 mice, experiments performed in triplicates for all experimental groups).