Replication kinetics of T cell escape mutants. Frequencies of mutations in the TW10 epitope or CypA binding loop were determined by comparing the longitudinal sequences to the T/F sequences for CH58 (a), CH470 (b), and CH40 (c). The days post screening are indicated. The T242N escape mutation and compensatory amino acids were introduced into the CH58 (d), CH470 (e), and CH40 (f) T/F viral genomes. The replication kinetics of the mutants and their corresponding T/F viruses were determined by measuring p24 concentrations in the cell culture supernatants. The amino acids associated with T cell escape at the position 242 are indicated in red while the amino acids associated with compensation of the fitness loss at the positions 219 and 247 are indicated in blue. Each virus was cultured in triplicate. Mean values ± standard deviations are shown.