A role of FCER1A and FCER2 polymorphisms in IgE regulation
ALLERGY
Authors: Sharma, V.; Michel, S.; Gaertner, V.; Franke, A.; Vogelberg, C.; von Berg, A.; Bufe, A.; Heinzmann, A.; Laub, O.; Rietschel, E.; Simma, B.; Frischer, T.; Genuneit, J.; Potaczek, D. P.; Kabesch, M.
Abstract
BackgroundBoth FCER2 and FCER1A encode subunits of IgE receptors. Variants in FCER1A were previously identified as major determinants of IgE levels in genome-wide association studies. MethodsHere we investigated in detail whether FCER2 polymorphisms affect IgE levels alone and/or by interaction with FCER1A polymorphisms. To cover the genetic information of FCER2, 21 single-nucleotide polymorphisms (SNPs) were genotyped by Illumina HumanHap300 BeadChip (5 SNPs) and the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS; 14 SNPs) in at least 1303 Caucasian children (651 asthmatics) (ISAAC II/ MAGICS population); genotypes of two SNPs were imputed. ResultsSNP rs3760687 showed the most consistent effect on total serum IgE levels (b [SE]=-0.38 [0.16]; P=0.016), while FCER2 polymorphisms in general were predominantly associated with mildly-to-moderately increased IgE levels (50th and 66th percentiles). Gene-by-gene interaction analysis suggests that FCER2 polymorphism rs3760687 influences IgE levels mainly in individuals not homozygous for the risk allele of FCER1A polymorphism rs2427837, which belongs to the major IgE-determining tagging bin in the population. ConclusionFCER2 polymorphism rs3760687 affects moderately elevated total serum IgE levels, especially in the absence of homozygosity for the risk allele of FCER1A SNP rs2427837.
Dexamethasone and Monophosphoryl lipid a induce a Distinctive Profile on Monocyte-Derived Dendritic cells through Transcriptional Modulation of genes associated With essential Processes of the immune response
FRONTIERS IN IMMUNOLOGY
Authors: Garcia-Gonzalez, Paulina A.; Schinnerling, Katina; Sepulveda-Gutierrez, Alejandro; Maggi, Jaxaira; Mehdi, Ahmed M.; Nel, Hendrik J.; Pesce, Barbara; Larrondo, Milton L.; Aravena, Octavio; Molina, Mar-A C.; Catalan, Diego; Thomas, Ranjeny; Verdugo, Ricardo A.; Aguillon, Juan C.
Abstract
There is growing interest in the use of tolerogenic dendritic cells (tolDCs) as a potential target for immunotherapy. However, the molecular bases that drive the differentiation of monocyte-derived DCs (moDCs) toward a tolerogenic state are still poorly understood. Here, we studied the transcriptional profile of moDCs from healthy subjects, modulated with dexamethasone (Dex) and activated with monophosphoryl lipid A (MPLA), referred to as Dex-modulated and MPLA-activated DCs (DM-DCs), as an approach to identify molecular regulators and pathways associated with the induction of tolerogenic properties in tolDCs. We found that DM-DCs exhibit a distinctive transcriptional profile compared to untreated (DCs) and MPLA-matured DCs. Differentially expressed genes downregulated by DM included MMP12, CD1c, IL-1B, and FCER1A involved in DC maturation/inflammation and genes upregulated by DM included JAG1, MERTK, IL-10, and IDO1 involved in tolerance. Genes related to chemotactic responses, cell-to-cell signaling and interaction, fatty acid oxidation, metal homeostasis, and free radical scavenging were strongly enriched, predicting the activation of alternative metabolic processes than those driven by counterpart DCs. Furthermore, we identified a set of genes that were regulated exclusively by the combined action of Dex and MPLA, which are mainly involved in the control of zinc homeostasis and reactive oxygen species production. These data further support the important role of metabolic processes on the control of the DC-driven regulatory immune response. Thus, Dex and MPLA treatments modify gene expression in moDCs by inducing a particular transcriptional profile characterized by the activation of tolerance-associated genes and suppression of the expression of inflammatory genes, conferring the potential to exert regulatory functions and immune response modulation.