TY - JOUR A1 - Kim, Mia A1 - Grimmig, Tanja A1 - Grimm, Martin A1 - Lazariotou, Maria A1 - Meier, Eva A1 - Rosenwald, Andreas A1 - Tsaur, Igor A1 - Blaheta, Roman A1 - Heemann, Uwe A1 - Germer, Christoph-Thomas A1 - Waaga-Gasser, Ana Maria A1 - Gasser, Martin T1 - Expression of Foxp3 in Colorectal Cancer but Not in Treg Cells Correlates with Disease Progression in Patients with Colorectal Cancer JF - PLoS ONE N2 - Background Measles virus (MV) causes T cell suppression by interference with phosphatidylinositol-3-kinase (PI3K) activation. We previously found that this interference affected the activity of splice regulatory proteins and a T cell inhibitory protein isoform was produced from an alternatively spliced pre-mRNA. Hypothesis Differentially regulated and alternatively splice variant transcripts accumulating in response to PI3K abrogation in T cells potentially encode proteins involved in T cell silencing. Methods To test this hypothesis at the cellular level, we performed a Human Exon 1.0 ST Array on RNAs isolated from T cells stimulated only or stimulated after PI3K inhibition. We developed a simple algorithm based on a splicing index to detect genes that undergo alternative splicing (AS) or are differentially regulated (RG) upon T cell suppression. Results Applying our algorithm to the data, 9% of the genes were assigned as AS, while only 3% were attributed to RG. Though there are overlaps, AS and RG genes differed with regard to functional regulation, and were found to be enriched in different functional groups. AS genes targeted extracellular matrix (ECM)-receptor interaction and focal adhesion pathways, while RG genes were mainly enriched in cytokine-receptor interaction and Jak-STAT. When combined, AS/RG dependent alterations targeted pathways essential for T cell receptor signaling, cytoskeletal dynamics and cell cycle entry. Conclusions PI3K abrogation interferes with key T cell activation processes through both differential expression and alternative splicing, which together actively contribute to T cell suppression. KW - T cells KW - gene regulation KW - alternative splicing KW - measles virus KW - T cell receptors KW - reverse transcriptase-polymerase chain reaction KW - TCR signaling cascade KW - cell cycle and cell division Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130340 VL - 8 IS - 1 ER -