Project description:gd T cells have an important yet incompletely defined role in inflammation associated with a variety of infectious and autoimmune conditions. To better understand the precise roles of gd T cells relative to ab T cells in a specific infection, we utilized Salmonella Enterica Serovar Typhimurium (S. typhimurium) infection in cattle as it is a leading cause of disease in cattle and closely approximates S. typhimurium-induced enterocolitis in humans. To best represent phenotype and gene expression changes occurring in the gut mucosa early in S. typhimurium infection, gd and ab T cells were collected directly from the mesenteric lymphatic ducts and analyzed by FACS or immediately sorted and processed for microarray analysis. Gene expression profiles were compared at intervals during infection within T cell subsets. The majority of gene expression changes in both subsets occurred 48 hours after infection. In response to S. typhimurium infection there was an increase in expression of several genes in gd T cells which were indicative of activation, proliferation and innate function, whereas in ab T cells gene expression changes suggested a lack of S. typhimurium-specific response. This work represents the first focus on gene expression trends in tissue-derived T lymphocytes in an in vivo model that is highly relevant to human S. typhimurium-induced enterocolitis. Experiment Overall Design: For one mock infection (calf 156) and two experimental S. typhimurium infections (calves 112 and 162), gd and ab lymphatic T cells were stained with GD3.8 directly conjugated to FITC, washed, and sorted on a Vantage SE cell sorter (BD Immunocytometry Systems) as previously described. Sorted gd and ab T cells were collected directly into TRIzol reagent (Invitrogen; calf 112) and lysed or suspended in Buffer RLT (Qiagen; calves 156 and 162) and lysed using Qiashredder columns, then frozen at -80oC. RNA was extracted following the manufacturerâs protocol for Trizol (Invitrogen) extraction, or RNeasy (Qiagen) column purification, assessed on a Bioanalyzer 2100 (Agilent Technologies), and amplified either using Affymetrix Two-cycle (calf 112) target labeling protocol with 100 ng total RNA or the One-cycle protocol (calves 156 and 162) with approximately 1.6 micrograms of total RNA as described in the GeneChip® Expression Analysis Technical Manual (June 2004). Hybridizations to Genechip® Bovine Genome Arrays (Affymetrix) were performed with 15 micrograms biotin labeled cRNA. Washing and staining was performed in the GeneChip® Fluidics Station 450 using the Midi_euk2v3 protocol. Chip scans were performed on the Affymetrix GeneChip® Scanner 3000. GeneChip® Operating Software (GCOS v.1.1, Affymetrix) was used for data collection. Experiment Overall Design: Table I represents annotated genes of potential interest that changed 2 fold or greater in expression between 0 and 48 hours post-Salmonella infection (calves 112 and 162) or mock-infection (calf 156) in T cell subsets.
Project description:Comparison of gd T cell clones with ab T cell clones that responded to the same antigen. Clones were identically stimulated with ConA/IL-2 and analyzed with two separate microarrays. Keywords: other
Project description:Comparison of gd T cell clones with ab T cell clones that responded to the same antigen. Clones were identically stimulated with ConA/IL-2 and analyzed with two separate microarrays. Keywords: other
Project description:We have begun to approach gd T cells more as prospective innate cells than as conventional T cells. Recent results indicated that purified gd T cells are primed directly in response to pathogen associated molecular patterns (PAMPs) to better respond to secondary signals and increase expression of chemokine and activation-related genes. In microarray and real time PCR analyses of RNA derived from bovine and human gd T cells, transcripts encoding Nod2 were repeatedly amplified. Nod2 is the intracellular receptor for muramyl dipeptide (MDP), a subunit of PGN, functions in regulating innate activities, and was thought to be expressed primarily in APCs. Given our repeated detection of Nod2 transcripts in gd T cells, the specific direct response of gd T cells to MDP was analyzed by microarray, real time PCR, proteome array and in a functional priming assay. The results indicate a subtle activation in response to MDP akin to priming, and suggest a unique mechanism for differential gene expression. Experiment Overall Design: PBLs from calf 129 were stained with GD3.8 directly conjugated to FITC, washed, and sorted on a Vantage SE cell sorter (BD Immunocytometry Systems) as previously described. PBLs from calves 150 and 151 were stained with GD3.8, and anti-Mouse IgG magnetic beads and sorted with MACS magnetic bead system (Miltenyi Biotec) as previously described to a purity of >98%. Sorted cells were rested overnight, stimulated for 4 hours then lysed in Buffer RLT and genomic DNA sheared using Qiashredder columns then frozen at -80oC. RNA was extracted following the manufacturerâs protocol for RNeasy (Qiagen) column purification, assessed on a Bioanalyzer 2100 (Agilent Technologies), and amplified using the Affymetrix One-cycle protocol with approximately 1.7micrograms of total RNA as described in the GeneChip® Expression Analysis Technical Manual (June 2004). Hybridizations to Genechip® Bovine Genome Arrays (Affymetrix) were performed with 15 mg biotin labeled cRNA. Washing and staining was performed in the GeneChip® Fluidics Station 450 using the Midi_euk2v3 protocol. Chip scans were performed on the Affymetrix GeneChip® Scanner 3000. GeneChip® Operating Software (GCOS v.1.1, Affymetrix) 19;20 was used for data collection.
Project description:With regulatory roles in development, cell proliferation and disease, micro-RNA (miRNA) biology is of great importance and a potential key to novel RNA-based therapeutic regimens. Biochemically based sequencing approaches have provided robust means of uncovering miRNA binding landscapes on transcriptomes of various species. However, a current limitation to the therapeutic potential of miRNA biology in cattle is the lack of validated miRNAs targets. Here, we use cross-linking immunoprecipitation (CLIP) of the Argonaute (AGO) proteins and unambiguous miRNA-target identification through RNA chimeras to define a regulatory map of miRNA interactions in the cow (Bos taurus). The resulting interactome is the deepest reported to date for any species, demonstrating that comprehensive maps can be empirically obtained. We observe that bovine miRNA targeting principles are consistent with those observed in other mammals. Motif and structural analyses define expanded pairing rules with most interactions combining seed-based pairing with distinct, miRNA-specific patterns of auxiliary pairing. Further, miRNA-target chimeras had predictive value in evaluating true regulatory sites of the miR-17 family. Finally, we define miRNA-specific targeting for >5000 mRNAs and determine gene ontologies (GO) for these targets. This confirmed repression of genes important for embryonic development and cell cycle progress by the let-7 family, and repression of those involved in cell cycle arrest by the miR-17 family, but it also suggested a number of unappreciated miRNA functions. Our results provide a significant resource for transcriptomic understanding of bovine miRNA regulation, and demonstrate the power of experimental methods for establishing comprehensive interaction maps.