Project description:The ability of dendritic cells (DC) to initiate immunity and induce antigen-specific tolerance makes DC ideal targets for pharmacological intervention into immune responses. NF-kB factors are a family of transcriptional regulators important for DC development and function. However, the identity of NF-kB target genes that are central to DC biology is largely unknown. In the present study inhibition of the NF-kB activation by the IkBa super repressor (IkBa-SR) and DNA microarray analysis were used to determine the repertoire of NF-kB responsive genes in DC. A number of immunomodulatory compounds have been suggested to target the NF-kB signalling pathway and/or NF-kB-mediated transcription of pro-inflammatory target genes. 1a,25-dihydroxyvitamin D3 (VD3) exerts its effects through the vitamin D3 receptor (VDR), a member of the nuclear hormone receptor superfamily. Microarray analysis was also selected as an approach of choice for the analysis of the effects of VD3 on the activation of DC, and to survey the involvement of VDR in repression of NF-kB regulated genes. These genes can be potentially useful targets for the development of more specific anti-inflammatory agents for clinical applications. Keywords: drug treatment, TNFa treatment, VD3 treatment DC were generated in vitro from bone marrow cells of VDRmut and VDRwt control mice as described previously (Hieronymus, T., T. C. Gust, R. D. Kirsch, T. Jorgas, G. Blendinger, M. Goncharenko, K. Supplitt, S. Rose-John, A. M. Muller, and M. Zenke. 2005. Progressive and controlled development of mouse dendritic cells from Flt3+CD11b+ progenitors in vitro. J Immunol 174:2552-2562). Immature DC were pre-treated with 1a,25-dihydroxyvitamin D3 (VD3), or left untreated. TNFa was added where appropriate, and cells incubated further for 4 h. Total RNA was amplified, labelled and hybridised to Affymetrix MOE430A arrays. TNFa up- and down-regulated genes, as well as genes affected by VD3 were analysed.
Project description:To investigate the expression of glycosyltransferases in dendritic cells and the changes in expression associated with maturation. RNA preparations from 5 different immature and mature dendritic cells subsets, with and without LPS from 2 different donors (20 different samples); (iDC, IL-10 iDC, Dexamethason iDC, Vitamin D3 iDC, im. macrophage), (mDC, IL-10 mDC, Dexamethason mDC, Vitamin D3 mDC, m. macrophage) were sent to both Microarray Core (E) and Core(C). The RNA was purified on an RNeasy Column, amplified, labeled, and hybridized to the Glycov3 microarrays.
Project description:The ability of dendritic cells (DC) to initiate immunity and induce antigen-specific tolerance makes DC ideal targets for pharmacological intervention into immune responses. NF-kB factors are a family of transcriptional regulators important for DC development and function. However, the identity of NF-kB target genes that are central to DC biology is largely unknown. In the present study inhibition of the NF-kB activation by the IkBa super repressor (IkBa-SR) and DNA microarray analysis were used to determine the repertoire of NF-kB responsive genes in DC. A number of immunomodulatory compounds have been suggested to target the NF-kB signalling pathway and/or NF-kB-mediated transcription of pro-inflammatory target genes. 1a,25-dihydroxyvitamin D3 (VD3) exerts its effects through the vitamin D3 receptor (VDR), a member of the nuclear hormone receptor superfamily. Microarray analysis was also selected as an approach of choice for the analysis of the effects of VD3 on the activation of DC, and to survey the involvement of VDR in repression of NF-kB regulated genes. These genes can be potentially useful targets for the development of more specific anti-inflammatory agents for clinical applications. Keywords: drug treatment, TNFa treatment, VD3 treatment
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
Project description:We performed single-cell RNA sequencing on bone marrow derived, cultured dendritic cells after CRISPR-knockout of Ndrg2, after vitamin D3 treatment or no treatment. In addition we performed single-cell RNA sequencing of wounds that had been treated with hydrogels seeded with Ndrg2-KO dendritic cells, control (untreated) dendritic cells or blank hydrogels.
Project description:Complex autoimmune diseases have proven difficult to dissect down to their causative genetic mechanisms. As a result, epidemiological data from different human association studies are often merged to arrive at a working hypothesis. In one of such examples, lack of sun exposure and consequent lower serum vitamin D3 levels has been proposed to increase risk of autoimmunity, attributing vitamin D3 an immune regulatory role. However, conclusive evidence demonstrating its efficacy in treating autoimmune diseases is missing. In this study, we have used a forward genetics approach to positionally identify polymorphic nucleotides controlling T cell-dependent inflammatory diseases using congenic mouse strains. Here, we identify the vitamin D3 receptor (Vdr) as a driver of inflammation. Congenic mice carrying a polymorphic Vdr allele overexpressed the receptor selectively in activated T cells, thereby escaping systemic calcaemic side effects that often constitute a confounding factor in the study of immunomodulation by vitamin D3. Mice overexpressing Vdr in T cells developed more severe collagen-induced arthritis (CIA) and exhibited an enhanced antigen-specific CD4+ T cell response. Deficiency of vitamin D3 completely protected mice from CIA by limiting the activation of antigen-specific T cell responses, and arthritis susceptibility was restored by re-administration of vitamin D3. We demonstrate that vitamin D3 signalling specifically through Vdr predominantly acts to enhance T cell proliferation, thereby contributing to inflammation. In conclusion, our results demonstrate that genetically determined expression of VDR codetermines the pro-inflammatory behaviour of activated T cells. Furthermore, our data suggest that the anti-inflammatory properties of vitamin D3 might be limited by high expression of VDR at the site of inflammation.
Project description:This experiment is designed to compare the effects of Vitamin D3 treatment of mouse bone marrow derived dendritic cells with control, untreated cells, and additional effects of maturation of either treated or control cells with LPS.
Project description:Translational research is commonly performed in the C57B6/J mouse strain, chosen for its genetic homogeneity and phenotypic uniformity. Here, we evaluate the suitability of the white-footed deer mouse (Peromyscus leucopus) as a model organism for aging research, offering a comparative analysis against C57B6/J and diversity outbred (DO) Mus musculus strains. Our study includes comparisons of body composition, skeletal muscle function, and cardiovascular parameters, shedding light on potential applications and limitations of P. leucopus in aging studies. Notably, P. leucopus exhibits distinct body composition characteristics, emphasizing reduced muscle force exertion and a unique metabolism, particularly in fat mass. Cardiovascular assessments showed changes in arterial stiffness, challenging conventional assumptions and highlighting the need for a nuanced interpretation of aging-related phenotypes. Our study also highlights inherent challenges associated with maintaining and phenotyping P. leucopus cohorts. Behavioral considerations, including anxiety-induced responses during handling and phenotyping assessment, pose obstacles in acquiring meaningful data. Moreover, the unique anatomy of P. leucopus necessitates careful adaptation of protocols designed for Mus musculus. While showcasing potential benefits, further extensive analyses across broader age ranges and larger cohorts are necessary to establish the reliability of P. leucopus as a robust and translatable model for aging studies.
Project description:The comparative analysis of the transcriptome of tolerogenic dendritic cells (tolDC) differentiated using different stimulus (either vitamin D3, dexamethasone or rapamycin) would allow to evidence potential common genes and pathways that could explain their potency as tolerance-inducing cells.
Project description:The active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), induces stable tolerogenesis in dendritic cells (DC). This process involves the Vitamin D receptor (VDR) which translocates to the nucleus, binds its cognate genomic sites and promotes epigenetic and transcriptional remodeling. In this study, we investigated the interplay between the vitamin D receptor (VDR) and transcription factors to induce DNA methylation changes, which might provide phenotypic stability to the tolerogenic phenotype of DCs.