TY  - JOUR
A1  - Vendelova, Emilia
A1  - Ashour, Diyaaeldin
A1  - Blank, Patrick
A1  - Erhard, Florian
A1  - Saliba, Antoine-Emmanuel
A1  - Kalinke, Ulrich
A1  - Lutz, Manfred B.
T1  - Tolerogenic transcriptional signatures of steady-state and pathogen-induced dendritic cells
JF  - Frontiers in Immunology
N2  - Dendritic cells (DCs) are key directors of tolerogenic and immunogenic immune responses. During the steady state, DCs maintain T cell tolerance to self-antigens by multiple mechanisms including inducing anergy, deletion, and Treg activity. All of these mechanisms help to prevent autoimmune diseases or other hyperreactivities. Different DC subsets contribute to pathogen recognition by expression of different subsets of pattern recognition receptors, including Toll-like receptors or C-type lectins. In addition to the triggering of immune responses in infected hosts, most pathogens have evolved mechanisms for evasion of targeted responses. One such strategy is characterized by adopting the host's T cell tolerance mechanisms. Understanding these tolerogenic mechanisms is of utmost importance for therapeutic approaches to treat immune pathologies, tumors and infections. Transcriptional profiling has developed into a potent tool for DC subset identification. Here, we review and compile pathogen-induced tolerogenic transcriptional signatures from mRNA profiling data of currently available bacterial- or helminth-induced transcriptional signatures. We compare them with signatures of tolerogenic steady-state DC subtypes to identify common and divergent strategies of pathogen induced immune evasion. Candidate molecules are discussed in detail. Our analysis provides further insights into tolerogenic DC signatures and their exploitation by different pathogens.
KW  - bacteria
KW  - helminths
KW  - immune evasion
KW  - mycobacteria
KW  - transcriptional profiling
KW  - tolerogenic dendritic cells
KW  - steady-state dendritic cells
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-175636
VL  - 9
IS  - 333
ER  - 
TY  - JOUR
A1  - Müller, Laura S. M.
A1  - Cosentino, Raúl O.
A1  - Förstner, Konrad U.
A1  - Guizetti, Julien
A1  - Wedel, Carolin
A1  - Kaplan, Noam
A1  - Janzen, Christian J.
A1  - Arampatzi, Panagiota
A1  - Vogel, Jörg
A1  - Steinbiss, Sascha
A1  - Otto, Thomas D.
A1  - Saliba, Antoine-Emmanuel
A1  - Sebra, Robert P.
A1  - Siegel, T. Nicolai
T1  - Genome organization and DNA accessibility control antigenic variation in trypanosomes
JF  - Nature
N2  - Many evolutionarily distant pathogenic organisms have evolved similar survival strategies to evade the immune responses of their hosts. These include antigenic variation, through which an infecting organism prevents clearance by periodically altering the identity of proteins that are visible to the immune system of the host1. Antigenic variation requires large reservoirs of immunologically diverse antigen genes, which are often generated through homologous recombination, as well as mechanisms to ensure the expression of one or very few antigens at any given time. Both homologous recombination and gene expression are affected by three-dimensional genome architecture and local DNA accessibility2,3. Factors that link three-dimensional genome architecture, local chromatin conformation and antigenic variation have, to our knowledge, not yet been identified in any organism. One of the major obstacles to studying the role of genome architecture in antigenic variation has been the highly repetitive nature and heterozygosity of antigen-gene arrays, which has precluded complete genome assembly in many pathogens. Here we report the de novo haplotype-specific assembly and scaffolding of the long antigen-gene arrays of the model protozoan parasite Trypanosoma brucei, using long-read sequencing technology and conserved features of chromosome folding4. Genome-wide chromosome conformation capture (Hi-C) reveals a distinct partitioning of the genome, with antigen-encoding subtelomeric regions that are folded into distinct, highly compact compartments. In addition, we performed a range of analyses—Hi-C, fluorescence in situ hybridization, assays for transposase-accessible chromatin using sequencing and single-cell RNA sequencing—that showed that deletion of the histone variants H3.V and H4.V increases antigen-gene clustering, DNA accessibility across sites of antigen expression and switching of the expressed antigen isoform, via homologous recombination. Our analyses identify histone variants as a molecular link between global genome architecture, local chromatin conformation and antigenic variation.
KW  - histone variants
KW  - genome architecture
KW  - single molecule real time (SMRT)
KW  - brucei genome
KW  - distance-dependent decay
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224265
VL  - 563
ER  -