Project description:"γc" cytokines are a family whose receptors share a “common gamma chain” signaling moiety, and play central roles in the differentiation, homeostasis and communications of all immunocyte lineages. As a resource to better understand their range and specificity of action, we profiled by RNAseq the immediate-early responses to the main γc cytokines, across all immunocyte lineages. The results show a different response landscape than expected: broader, with a strong Myc-controlled resetting of biosynthetic and metabolic pathways, a major downregulation component, and extensive overlap between cytokines (one cytokine doing in one cell what another does elsewhere). Various mechanisms appear involved: fast transcriptional activation, chromatin remodeling, and mRNA destabilization. Other surprises are uncovered: IL2 effects in mast cells, major shifts between follicular and marginal-zone B cells, paradoxical and cell-specific cross-talk between IFN and γc signaling, or an NK-T like program induced by IL21 in CD8+ T cells.
Project description:Analysis of how different gamma chain family cytokines influence CD8 T cell differentiation. Naïve CD8 T cells were isolated from the spleens OT-I Thy1.1 TCR Tg mice. Whole splenocytes from wild-type C57BL/6 mice were used as stimulator cells. Purified naïve wild-type OT-I (1×106/well) were stimulated with OVA peptide (SIINFEKL) pulsed (5 µg/ml) and irradiated (2,000 rads) syngeneic splenocytes (6×106/well) in 24-well plates. Forty-eight hours later, activated OT-I T cells were harvested and viable cells were enriched over a Ficoll-paque gradient and washed with cRPMI prior to being reseeded in cRPMI (5×105 cells/ml) and treated with the media supplemented with various γc cytokines (IL-2, IL-4, IL-7, IL-15 and IL-21). Experimental samples were treated with 100 ng/ml of their respective gamma chain cytokine and incubated at 37ºC for 24 hours. RNA was isolated using either the RNeasy Mini kit, or a combination of TRIzol reagent and the Direct-zol RNA miniprep kit, all following manufacturer protocols. Two biological replicates for mRNA analysis were prepped using the RNeasy kit. The third replicate was prepped using the Trizol/Direct-zol approach. The quality and quantity of RNA samples was further analyzed on the Bioanalyzer. Labeled target cDNA was prepared from total RNA samples using the Ambion MessageAmp Premier protocol (3’IVT assay). Each sample target was hybridized to a Mouse 430 2.0 GeneChip array. Image processing and expression analysis were performed using Affymetrix GeneChip Command Console (AGCC) v. 3.1.1 and Affymetrix Expression Console v.1.1 software, respectively. Data from all biological replicates and conditions was imported into the Affymetrix Expression Console and normalized (RMA). RNA processing and microarray hybridization were performed by the Oregon Health & Science University Gene Microarray Shared Resource core facility in Portland, Oregon.
Project description:Analysis of changes in gene expression after incubation of dendritic cells with immune complexes or medium. Since the dendritic cells are derived from three different mouse strains, either wild type, Fcγ receptor IIb KO (expresses only activating Fcγ receptors) or Fc receptor γ chain KO (expresses only inhibitory Fcγ receptor), the analysis gives important insight into the roles of the activating versus inhibiting Fcγ receptors on dendritic cells.
Project description:Intracerebral hemorrhage (ICH) induces alterations in the gut microbiota composition, significantly impacting neuroinflammation post-ICH. However, the impact of gut microbiota absence on neuroinflammation following ICH-induced brain injury remain unexplored. Here, we observed that the gut microbiota absence was associated with reduced neuroinflammation, alleviated neurological dysfunction, and mitigated gut barrier dysfunction post-ICH. In contrast, recolonization of microbiota from ICH-induced SPF mice by transplantation of fecal microbiota (FMT) exacerbated brain injury and gut impairment post-ICH. Additionally, microglia with transcriptional changes mediated the protective effects of gut microbiota absence on brain injury, with Apoe emerging as a hub gene. Subsequently, Apoe deficiency in peri-hematomal microglia was associated with improved brain injury. Finally, we revealed that gut microbiota influence brain injury and gut impairment via gut-derived short-chain fatty acids (SCFA).
Project description:An early settlement of a complex gut microbiota can protect against gastro-intestinal dysbiosis, but the effects of neonatal microbiota colonization and early life feeding of medium chain triglycerides on the maturation of the porcine gastric mucosa are largely unknown. The transcriptome of the oxyntic mucosa of 24 caesarian-derived pigs previously associated with microbiota of different complexity and fed a diet fortified or not with medium chain fatty acids was studied. Pigs received pasteurized sow colostrum at birth (d0), 2 mL of starter microbiota (10^7 CFU of each Lactob. Amylovorus (LAM), Clostr. glycolicum, and Parabacteroides spp.) on d1-d3 of age and either a placebo inoculant (simple association, SA) or an inoculant consisting of diluted feces of an adult sow (complex association, CA) on d3-d4 of age. Then half of pigs was fed a moist diet (CON) or, for the remaining half, CTRL fortified in medium chain triglycerides with 7% coconut oil ( MCT). Gastric samples were obtained at on euthanised pigs at 3 weeks of age.
