Figure 2. Modulation of T Cell Activation by DNA-CARζ Length and Sequence.
(A) Thresholded images of phophoERK and DAPI staining of JRT3 cells responding to increasing 16-mer DNA ligand on SLBs (15 min). Scale bar, 100 μm. See also Figure S2.
(B) Dose-response curves for DNA ligands of varying hybridization lengths. The total ligand DNA length remained constant by adding non-hybridizing Ts. Mean ± SD (n = 3).
(C) Stepwise conversion of A/T to G/C base pairs increases the potency of the 11-mer DNA ligand for inducing phosphoERK signaling. Scale bar, 100 μm. Mean ± SD of each ligand density measured in triplicate from one representative experiment.
(D) Single ligand-receptor lifetimes by TIRF microscopy. An example distribution of lifetimes from one DNA ligand. The observed (τobs) and photobleach-corrected (τcorr) lifetimes are shown for the 11-mers (mean ± SEM from three separate experiments); for data of 13-mer and 16-mer and all histograms, see Figure S2.
