Evidence of CD4+ T cell-mediated immune pressure on the Hepatitis C virus genome by Lucas, M, Deshpande, P, James, I, Rauch, A, Pfafferott, K, Gaylard, E, Merani, S, Plauzolles, A, Lucas, A, McDonnell, W, Kalams, S, Pilkinton, M, Chastain, C, Barnett, L, Prosser, A, Mallal, S, Fitzmaurice, K, Drummer, H, Ansari, M, Pedergnana, V, Barnes, E, John, M, Kelleher, D, Klenerman, P, Gaudieri, S