FIG. 3.

Activation of anti-LCMV GP92-101, D95-specific CTL. (A) Agonism assay. ⁵¹Cr-labeled RMA were pulsed with increasing concentrations of D95 or N95 peptides (10⁻¹² to 10⁻⁷ M), and D95-specific CTL were added at an effector/target ratio of 10:1. After 4 h of incubation at 37°C, the ⁵¹Cr content of supernatants was determined. (B) Antagonism assay (cold target inhibition assay). ⁵¹Cr-labeled RMA were pulsed with a suboptimal concentration (33 pM) of the D95 peptide, and cold RMA were pulsed with increased concentrations (10⁻¹⁰ to 10⁻⁴ M) of N95 or NP396-404 for 1 h at 37°C. After three washes in culture medium to remove excess free peptides, ⁵¹Cr-labeled RMA and cold RMA were mixed at a 1:3 ratio. CTL were then added at a ratio of 10:1 with ⁵¹Cr-labeled RMA. After 4 h at 37°C, the supernatant was analyzed as described above.