Figure 1. Limited dynamic range of T lymphocyte activation snapshots at the individual cell level.
Varied numbers (NTcell) of 5C.C7 TCR Transgenic Rag2−/− T cells were cultured in duplicate in 200 µl of complete medium with 5.105 I-Ek-expressing B10.A Cd3e−/−splenocytes pulsed with varied concentrations of K5 peptide ([Antigen]). (A and B) Cells were harvested at varied timepoints and analyzed by flow cytometry for phosphorylation of ERK, upregulation of IL-2Rα, production of IL-2 via a Miltenyi IL-2 secretion assay, or dilution of Cell Trace Violet (CTV) upon cell proliferation. These measurements demonstrate (A) the bimodality of T cell activation as well as (B) the limited dynamics range of response for varied doses of antigens. (C) Supernatants were also collected at 12 hr and [IL-2] was measured by ELISA.