A cell topography-based mechanism for ligand discrimination by the T cell receptor by Fernandes, R, Ganzinger, K, Tzou, J, Jönsson, P, Lee, S, Palayret, M, Santos, A, Carr, A, Ponjavic, A, Chang, V, Macleod, C, Lagerholm, B, Lindsay, A, Dushek, O, Tilevik, A, Davis, S, Klenerman, D