A2.6 Cell-Specific Type I IFN Signatures in Autoimmunity and Viral Infection: What Makes the Difference?

Abstract

Background Gene expression profiling experiments using peripheral blood mononuclear cells (PBMCs) revealed a crucial role of type I interferon (IFN) in the pathogenesis of systemic lupus erythematosus (SLE). However, it is almost unknown how particular leukocyte subsets contribute to the overall type I IFN signature described for PBMCs. Furthermore, a detailed analysis of how IFN signatures differ in autoimmune disease from that observed after viral infection is missing so far. Therefore, we compared expression levels of 2442 IFN signature genes in peripheral CD4+ T helper cells and monocyte (Mo) subsets isolated from patients with SLE, healthy donors (ND) and ND vaccinated against yellow fever by global gene expression profiling. Materials and Methods Peripheral blood from 8 patients with SLE and 4 ND were recruited. Same ND were examined before and after immunisation by yellow fever vaccine. After sorting cells, isolated RNA were applied to Affymetrix Human Genome U133 Plus 2.0 Array. Data analysis was done using BioRetis database, Genesis Software and Ingenuity Pathway Analysis (IPA). Results 98/165/173 probe sets (CD4+ T cells/CD16- inflammatory Mo/CD16+ resident Mo, respectively, fold change >= 2,