CD4 and infection: The delayed replication kinetics in 3D collagen was reflected in a delayed increase in infected CD4 T cells (Fig. 1e, Fig. S1 Supplementary Fig. 2c), was associated with a moderate reduction in overall infection in most donors (Supplementary Fig. 2d), and resulted in markedly delayed CD4 T-cell depletion with less pronounced overall loss of CD4 T cells over the course of the experiment (Fig. 1f, Supplementary Fig. 2e).