Fig. 5

Fitness cost of the K43R mutation. a Replication of CH0131 T/F virus, the K43R mutant and the N323tc mutant were determined by culturing each virus independently in primary CD4⁺ T cell. Relative fitness costs of the K43R mutant (b) and the N323tc mutant (d) were determined by measuring the proportions of both compared viruses in the same cell culture using the competitive PASS fitness assay. Fitness costs of the K43R mutant (c) and the N323tc mutant (e) were determined after three passages. All experiments were carried out in triplicate. Mean ± standard deviation is shown