Multidimensional analysis of naive CD4+ T cells. Magnetic cell sorting, 13-parameter flow cytometry, transcription factor profiling and cytokine bead arrays were 'combined' to determine the effect of stimulation on immunophenotyped naive CD4+ T cells(CD3+CD4+CD8-CD45RA+CD62L+ CD11adimCD27+CD28+). (a) Intracellular IL-2 and phosphorylated Erk1/2(Phospho-Erk1/2) were correlated with surface phenotype and activation markers CD69 and CD25. Numbers in quadrants indicate percentages of each population. (b) Cell cycle analysis of CD4+ T cells stimulated with CD3, CD3 plus CD28, or CD3 and LFA-1 ligand. Cells in the G0, G1, and S + G2/M phases of the cell cycle were determined by double staining for expression of Ki-67 and DNA content(propidium iodide; PI). Low Ki-67- were considered cells in G0; Ki-67+ signals with 2n DNA, cells in G1; and Ki-67+ signals with >2n DNA, cells in S or G2/M.

Perez, OD, Mitchell, D., Jager, G., South,S., Murriel, C., McBride, J., Herzenberg, LA., Kinoshita, S. and Nolan, GP. Leukocyte functional antigen 1 lowers T cell activation thresholds and signaling through cytohesin-1 and Jun-activating binding protein 1. Nature Immunology 2003 4:1083-92