BioProject

Differentiation of naive CD8 T cells into cytotoxic effector cells requires three distinct signals- antigen (signal 1), costimulation -B7-1 (signal 2) and cytokine, either interleukin-12, interferon-a/b, or IL-21 (signal 3). More...

Differentiation of naive CD8 T cells into cytotoxic effector cells requires three distinct signals- antigen (signal 1), costimulation -B7-1 (signal 2) and cytokine, either interleukin-12, interferon-a/b, or IL-21 (signal 3). Interaction of naive CD8 T cells with antigen and B7-1 programs cell division and proliferation whereas the presence of cytokines- IL-12, IFNa/b or IL-21 promote survival, differentiation and memory establishment. In the absence of signal 3, the cells interacting with antigen/B7-1 undergo tolerance induction. Previous work had analyzed the regulation of mRNA expression changes induced by IL-12 and IFN-a and cells stimulated with antigen, B7-1 and cytokine by comparing mRNA expression levels in naïve CD8 T cells, cells stimulated with 2 signals (antigen and B7-1) (Agarwal, P.A., A. Raghavan, S.L. Nandiwada, J.M. Curtsinger, P.R. Bohjanen, D.L. Mueller and M.F. Mescher. Gene regulation and chromatin remodeling by IL-12 and Type I interferon in programming for CD8 T cell effector function and memory. J. Immunol. 183:1695-1704 (2009). PMCID: PMC2893405). That microarray data was deposited in the NCI GEO database and can be found at /geo/query/acc.cgi?acc_GSE15930. The objective of the current study was to carry out the same analysis to determine IL-21-dependent changes in mRNA expression in CD8 T cells responding to antigen and B7-1-dependent costimulation in the absence or presence of IL-21. Overall design: The programming for development of function and memory in presence of signal 3 occurs over three days of initial stimulation, and antigen, B7-1 and either IL-12, IFNa/b or IL-21 must be present for most of this period to achieve maximal responses. We analyzed gene expression at 48 and 72 hours in cells stimulated in vitro with antigen and B7-1 alone or along with IL-21. Less...