Project description:The aim of this study was to quantify the impact of NOD genetic vatiation on thymic negative selection transcriptional programs. Pre-selected BDC2.5 TCR Tg DP thymocytes from non-selecting B6 and NOD.H2b backgrounds were purified (Dynal CD8 FlowComp), mixed in a 1:1 ratio and stimulated with BDC mimotope-loaded TCRa-/-/NOD splenocytes for indicated periods of time and double sorted by FACS as Thy1.2+Dump-CD4+CD8+; Dump includes CD19, Gr1, CD11b, CD11c, CD49b. Following cell sorting into trizol, RNA was purified, labeled and hybridized to Affymetrix arrays. experiment type: unstimulated versus stimulated BDC/B6.Rag-/- and BDC/NOD.H2b.Rag-/- DP thymocytes
Project description:This experiment compares the transciptional changes in antigen specific murine CD8 T cells (P14 T cells) after exposure in vivo to dendritic cells (DC) pulsed with low dose cognate peptide (1uM KAVYNFATC), high dose cognate peptide (100uM KAVYNFATC) or no antigen. Splenic dendritic cells were freshly isolated, peptide pulsed, washed and then adoptively transferred s.c. to the right footpad of C57BL/6 hosts. After 18h, freshly isolated P14 CD8 T cells were labelled with CMFDA and adoptively transferred iv. Two hours after T cell transfer, anti-L selectin antibody was given iv. At 12 and 24 hours, recipients were sacrificed and The right popliteal LN was harvested at 12 or 24h post T cell transfer and a single cell suspension was created and stained with PE CD4, B220 and CD19 (dump channel). Cells were then sorted on a FacsARIA for being non-doublets, CMFDA positive and dump channel negative.
Project description:This experiment compares the transciptional changes in antigen specific murine CD8 T cells (P14 T cells) after exposure in vivo to dendritic cells (DC) pulsed with low dose cognate peptide (1uM KAVYNFATC), high dose cognate peptide (100uM KAVYNFATC) or no antigen. Splenic dendritic cells were freshly isolated, peptide pulsed, washed and then adoptively transferred s.c. to the right footpad of C57BL/6 hosts. After 18h, freshly isolated P14 CD8 T cells were labelled with CMFDA and adoptively transferred iv. Two hours after T cell transfer, anti-L selectin antibody was given iv. At 12 and 24 hours, recipients were sacrificed and The right popliteal LN was harvested at 12 or 24h post T cell transfer and a single cell suspension was created and stained with PE CD4, B220 and CD19 (dump channel). Cells were then sorted on a FacsARIA for being non-doublets, CMFDA positive and dump channel negative. This experiment compares the transciptional changes in antigen specific murine CD8 T cells (P14 T cells) after exposure in vivo to dendritic cells (DC) pulsed with low dose cognate peptide (1uM KAVYNFATC), high dose cognate peptide (100uM KAVYNFATC) or no antigen. Splenic dendritic cells were freshly isolated, peptide pulsed, washed and then adoptively transferred s.c. to the right footpad of C57BL/6 hosts. After 18h, freshly isolated P14 CD8 T cells were labelled with CMFDA and adoptively transferred iv. Two hours after T cell transfer, anti-L selectin antibody was given iv. At 12 and 24 hours, recipients were sacrificed and The right popliteal LN was harvested at 12 or 24h post T cell transfer and a single cell suspension was created and stained with PE CD4, B220 and CD19 (dump channel). Cells were then sorted on a FacsARIA for being non-doublets, CMFDA positive and dump channel negative. The experiment was conducted for 39 samples out of which 35 passsed transcriptional quality control tests. The phenotypic distribution for the 35 samples includes: (1) high dose (100uM KAVYNFATC ) cognate peptide pulsed samples harvested at 12h post T cell transfer: 6 biological replicates (2) high dose (100uM KAVYNFATC ) cognate peptide pulsed samples harvested at 24h post T cell transfer: 7 biological replicates (3) low dose (1uM KAVYNFATC) cognate peptide pulsed samples harvested at 12h post T cell transfer: 6 biological replicates (4) low dose (1uM KAVYNFATC) cognate peptide pulsed samples harvested at 24h post T cell transfer: 9 biological replicates (5) no antigen pulsed samples harvested at 12h post T cell transfer: 3 biological replicates (6) no antigen pulsed samples harvested at 24h post T cell transfer: 4 biological replicates.
Project description:Uracil in DNA can be generated as a result of cytosine deamination or dUMP misincorporation. However, its distribution in the human genome is poorly understood, due to the lack of a sensitive detection method. Here we present “dU-seq”, a selective labeling and pull-down technology, to profile uracil in the human genome. dU-seq specifically labels uracil-containing DNA via an in vitro base excision repair reaction and identifies thousands of uracil peaks in the human genome.
Project description:Gene expression profiling of Bone Marrow FoxP3+ Treg cells. Glatman Zaretsky et al. revealed an unexpected role for Tregs in plasma cell biology. Here we determined the gene-expression profile of this new subset of FoxP3+ Treg cell, which express high levels of Treg effector molecules, similar to other non-lymphoid tissue Tregs. Gene-profiling of BM Tregs. Bone marrow Treg cells (30k) (gfp+CD25hiCD4+TCRβ+) (dump negative: CD19-CD8α-TCRγδ-CD11b-CD11c-NK1.1-Gr-1-Ter-119-) were triple-sorted from pools of two to three reporter mice (C57BL/6 Foxp3-IRES-gfp, 9 week-old males) into trizol per ImmGen SOP. RNA was amplified, labeled and hybridized to Affymetrix Mouse Gene 1.0 ST Arrays (Expression Analysis)
Project description:H2A.B is a unique histone H2A variant that shares only 40 ~ 50 % sequence identity with canonical H2A. It has only been identified in mammals and has quickly evolved with remarkable sequence diversity among different species. H2A.B is ubiquitously expressed in most cells and tissues. It is mainly deposited in gene body region. The localization of H2A.B is associated with methylated CpG islands in mouse ES cells. H2A.B facilitates transcription elongation to go through methylated CpG islands in the gene bodies. One typical example is that H2A.B regulates transcription elongation at imprinted loci. We found H2A.B enriched in some methylated loci. Using ChIP-seq and MeDIP-seq, we test the correlation of H2A.B and DNA methylation.
Project description:The use of DNA microarrays to identify nucleotide variation is almost 20 years old. A variety of improvements in probe design and experimental conditions have brought this technology to the point that single-nucleotide differences can be efficiently detected in unmixed samples, although developing reliable methods for detection of mixed sequences (e.g. heterozygotes) remains challenging. Surprisingly, a comprehensive study of the probe design parameters and experimental conditions that optimize discrimination of single nucleotide polymorphisms (SNPs) has yet to be reported, so the limits of this technology remain uncertain. By targeting 24,549 SNPs that differ between two Saccharomyces cerevisiae strains, we studied the effect of SNPs on hybridization efficiency to DNA microarray probes of different lengths under different hybridization conditions. We found that the critical parameter for optimization of sequence discrimination is the relationship between probe melting temperature (Tm) and the temperature at which the hybridization reaction is performed. This relationship can be exploited through the design of microarrays containing probes of equal Tm by varying the length of probes. We demonstrate that using such a microarray we detect >90% homozygous SNPs and >80% heterozygous SNPs using the SNPScanner algorithm. The optimized design and experimental parameters determined in this study should guide DNA microarray designs for applications that require sequence discrimination such as mutation detection, genotyping of unmixed and mixed samples and allele-specific gene expression. Moreover, designing microarray probes with optimized sensitivity to mismatches should increase the accuracy of standard microarray applications such as copy number variation detection and gene expression analysis. Keyword(s): MutationDetection_CGH
Project description:The continuing reports of plastic pollution in various ecosystems highlight the threat posed by the ever-increasing consumption of synthetic polymers. Therefore, Pseudomonas capeferrum TDA1, a strain recently isolated from a plastic dump site, was examined further regarding its ability to degrade polyurethane (PU) compounds. The previously reported degradation pathway for 2,4-toluene diamine (2,4-TDA), a precursor and degradation intermediate of PU, could be confirmed by RNA-seq in this organism. In addition, different cell fractions of cells grown on a PU oligomer were tested for extracellular hydrolytic activity using a standard assay. Strikingly, purified outer membrane vesicles (OMV) of P. capeferrum TDA1 grown on a PU oligomer showed higher esterase activity than cell pellets. Hydrolases in the OMV fraction possibly involved in extracellular PU degradation were identified by mass spectrometry. On this basis, we propose a model for extracellular degradation of polyester-based PUs by P. capeferrum TDA1 involving the role of OMVs in synthetic polymer degradation.
Project description:The developmentally regulated 26- to 32-nt siRNAs (scnRNAs) are loaded to the Argonaute protein Twi1p and display a strong bias for uracil at the 5' end. In this study, we used deep sequencing to analyze loaded and unloaded populations of scnRNAs. We show that the size of the scnRNA is determined during a pre-loading process, whereas their 5' uracil bias is attributed to both pre-loading and loading processes. We also demonstrate that scnRNAs have a strong bias for adenine at the third base from the 3' terminus, suggesting that most scnRNAs are direct Dicer products. Furthermore, we show that the thermodynamic asymmetry of the scnRNA duplex does not affect the guide and passenger strand decision. Finally, we show that scnRNAs frequently have templated uracil at the last base without a strong bias for adenine at the second base indicating non-sequential production of scnRNAs from substrates. These findings provide a biochemical basis for the varying attributes of scnRNAs, which should help improve our understanding of the production and turnover of scnRNAs in vivo.
Project description:We used ChIP-seq to examine the requirements for inheritance of H3K9me at endogenous and ectopic loci. H3K9me2 and H3K9me3 ChIP-seq in multiple S. pombe strains