Presentation on theme: "Using IPA to study immune cells CSC workshop on Pathway Analysis Espoo, November 12, 2007 Helena Ahlfors Turku Centre for Biotechnology."— Presentation transcript:
Using IPA to study immune cells CSC workshop on Pathway Analysis Espoo, November 12, 2007 Helena Ahlfors Turku Centre for Biotechnology
Lehtonen & Ahlfors et al. Journal of Leukocyte Biology, 2007
Aim of the study Identification of cell-type specific differences in gene expression profiles of monocytes, macrophages (Mf) and dendritic cells (DCs)
Experimental setting Monocyte Macrophage GM-CSF + IL-4 Dendritic cell Buffy coat Ficoll gradient Percoll gradient depletion of T and B cells Gene expression profiling with Affymetrix HG-U133A arrays
CD14 CD1b DC-SIGN =CD209 Monocyte 3d M 7d M 3d DC7d DC Known Mf and DC markers
Monocyte 0d3d 7d Dendritic cell Macrophage GM-CSF, IL-4 + GM-CSF Number of regulated genes Filtering criteria: not NC not AA SLR ≥ 1 reproducible differences
Genes regulated both at 3-d and 7-d time point * Mf vs DC *
TGF FZD WNT5A SOCS Fc R1A Fc R1A C3 TCF7L Mo M DC M DC 3d 7d Mo M DC M DC 3d 7d Mo M DC M DC 3d 7d Validation of the expression of a selected set of genes by quantitative RT-PCR
IPA / Canonical pathways Mf DC
Conclusions I GM-CSF and IL-4 regulate the expression of almost 900 genes during the differentiation of macrophages and DCs. Altogether 196 genes were differentially regulated in macrophages and DCs throughout the 7-day differentiation. Most of these genes code for factors involved in the signaling from cell surface to nucleus. Several novel genes with unknown molecular function were identified. These genes may cooperate with the previously known differentiation promoting factors and thus have an essential role in macrophage and DC differentiation process. Ingenuity Pathways Analysis revealed that canonical pathways of particular interest are differentially regulated in macrophages and DCs.
Kumar et al. Molecular Systems Biology, 2007, In press
Aim of the study Examine how the BCR-dependent intracellular signaling network adapts to targeted perturbations induced through siRNA-mediated depletion of select signaling intermediates.
BCR signaling network
Experimental setting mock CaMKIIPyk2PLCγPKCδ Transfecting the cells with siRNA oligos Stimulating the cells with anti- IgG for 30 min Gene expression profiling with Illumina mouse-6 beadchips B cell
Conclusions II The depletion of any given component from the BCR signaling network resulted in significant alterations in phophorylation profiles of the other intermediates. This effect was not localized but extended over to intermediates that were not within the canonical signaling pathways to which each of the depleted molecules belonged. The depletion of individual nodes also reflected alterations in signal processing with corresponding alterations in the cellular phenotypic response as several tens of genes were either strongly induced or downregulated. The most significant gene regulatory network identified by IPA was a Myc-centric network with a proposed function in cell cycle regulation.
Acknowledgements Turku Centre for Biotechnology Prof Riitta Lahesmaa National Public Health Institute Prof Ilkka Julkunen Anne Lehtonen Ville Veckman Minja Miettinen International Centre for Genetic Engineering and Biotechnology (ICGEB), Delhi, India Prof Kanury V.S. Rao Dhiraj Kumar Ravichandran Srikanth Finnish Microarray Centre Miina Miller Päivi Junni Tiia Heinonen National Graduate School of Informational and Structural Biology