by negative magnetic separation (EasySep Human Naive CD4 + T cell Enrichment Kit, Stem Cell Technologies). Cells were plated at a density of 100,000 per well in a 96-well round bottom plate and stimulated with anti-CD3/28 beads (Human T-Activator Dynabeads, Life Technologies) for 5 days. Where indicated, cultures were treated with 10 ng/ml IL-12 and/or 20 ng/ml IL-2 (both from Peprotech). Statistics. Data were analyzed using Prism statistical software. Statistical significance was assessed using the Mann-Whitney test. Paired data were analyzed using a 2-tailed paired Student's t test. A P value of less than 0.05 was considered significant.

No abstract