Effect of rapamycin and KU-0063794 on CTL gene expression

Comparison of transcriptional profile of CD8 cytotoxic T lymphocytes terated with the mTORC1 inhibitor rapamycin or the mTOR inhibitor KU-0063794 and comparison with proteomic analysis. Abstract: High resolution mass spectrometry maps the cytotoxic T lymphocyte (CTL) proteome and the impact of mammalian target of rapamycin complex 1 (mTORC1) on CTL. We show that the CTL proteome is dominated by metabolic regulators and granzymes and that mTORC1 selectively represses and promotes expression of a protein subset (~10%) including key CTL effector molecules and signaling proteins. mTORC1 also controlled flux through a subset of metabolic pathways rather than acting as an on/off switch for global CTL metabolism. Proteomic data highlighted the potential for mTORC1 negative control of phosphatidylinositol (3,4,5)-trisphosphate (PIP3) production in CTL. Further work revealed that mTORC1 represses PIP3 production and determines the mTORC2 requirement for activation of the serine/threonine kinase AKT. Unbiased proteomic analysis thus provides a comprehensive understanding of CTL identity and mTORC1 control of CTL function. Spleens from three biological replicates (control and drug treated samples were generated from the same spleens) from P14 TCR transgenic mice were harvested and activated with the antigenic peptide gp33-41 and IL-2/12 for 48h. After activation, cells were further clonally expanded in the presence of IL-2/12 for a further 96h prior to RNA extraction and hybridization to Affymetrix microarray.