Project description:B10.BR mice were lethally irradiated and infused with 5000 FACS-sorted HSCs and 1000000 T cells from C57B/6J donors with 50000 FACS-purified wild-type pDCs or VIP-KO pDCs. On day 8 and day 15 after the bone marrow transplant, donor T cells were isolated and the RNA expression were detected.
Project description:Transcriptional profiling of M.tb H37Rv cells comparing control wild type H37Rv with H37Rv cells electroporated with constitutive expression plasmid pVV16 expressing ESAT-6 binding peptide SL3. The expression of SL3 makes H37Rv less virulent during ex vivo and BalB/c mice infections, sequesters ESAT-6 inside M.tb cells and cause severe defects in mycobacterial morphology. Goal was to determine the effects of SL3 expression on global H37Rv gene expression.
Project description:Type I interferons (IFN) are crucial mediators of human innate and adaptive immunity and are massively produced from plasmacytoid dendritic cells (pDC). IRF7 is a critical regulator of type I IFN production when pathogens are detected by TLR7/9 in pDC. However, hyperactivation of pDC can cause life-threatening autoimmune diseases. To avoid the deleterious effects of aberrant pDC activation, tight regulation of IRF7 is required. Nonetheless, the detailed mechanisms of how IRF7 transcription is regulated in pDC are still elusive. To this end, we identified the global gene expression changes after stimulation of human primary pDC with the TLR9 agonist CpGB. We identified that the transcription factor MYC is prominently upregulated upon CpGB engagement in pDC. Moreover, when we knocked down MYC in the pDC-like cell line GEN2.2, production of interferon-stimulated genes (ISGs) was dramatically increased and was further enhanced by CpGB. Interestingly, MYC is shown to be recruited to the IRF7 promoter region through interaction with NCOR2/HDAC3 for its repression, and HDAC3 inhibition enhanced IRF7 expression and IFNβ production. Interestingly, activation of TLR9-mediated NF-kB and MAPK and nuclear translocation of IRF7 were greatly enhanced by MYC depletion. Pharmaceutical inhibition of MYC recovered IRF7 expression, further confirming the negative role of MYC in the antiviral response by pDC. Furthermore, the inverse correlation of MYC and IRF7 was validated in psoriasis skin sample datasets. Therefore, our results identify the novel immunomodulatory role of MYC in human pDC and may add to our understanding of aberrant pDC function in autoimmune diseases.
Project description:Transcriptional profiling of M.tb H37Rv cells comparing control wild type H37Rv with H37Rv cells electroporated with constitutive expression plasmid pVV16 expressing ESAT-6 binding peptide SL3. The expression of SL3 makes H37Rv less virulent during ex vivo and BalB/c mice infections, sequesters ESAT-6 inside M.tb cells and cause severe defects in mycobacterial morphology. Goal was to determine the effects of SL3 expression on global H37Rv gene expression. Two color Experiment,Organism: Mycobacterium Tuberculosis, ilife Discoveries designed Custom Mycobacterium tuberculosis on 8x15k GE Microarray. Two-condition experiment, H37Rv vs. H37Rv/SL3. Biological replicates: 2 biological control H37RV replicates labelled with Cy3, 2 SL3 biological expressing replicates labelled with Cy5.
Project description:In our study, we investigated the effect of Vasoactive intestinal peptide (VIP) on murine intestinal stem cell (ISC) activity and differentiation in homeostatic conditions and following irradiation-induced injury. We utilized a model of murine intestinal organoids and observed that VIP promotes epithelial differentiation towards a secretory phenotype predominantly via the p38 MAPK pathway. Moreover, VIP prominently modulates epithelial proliferation as well as the number and proliferative activity of Lgr5-EGFP+ ISC under homeostatic conditions. Further analysis revealed that in vitro acute irradiation injury renders Lgr5-EGFP+ ISC even more susceptible to modulations by VIP, which results in the strong promotion of epithelial regeneration by VIP. Finally, these effects by VIP translate into an in vivo model of abdominal irradiation, where VIP was shown to prominently mitigate radiation-induced injury. Taken together, our findings indicate a prominent role of VIP in modulating ISC behavior in intestinal homeostasis and its potential to promote intestinal regeneration following acute irradiation injury.
Project description:Paracrine signals play pivotal roles in organ homeostasis. Mesenchymal stromal cells (MSCs) play a key role in regulating epithelium homeostasis in the intestine while their paracrine effects are poorly characterized. Here, we identified prostaglandin E2 (PGE2) secreted by cyclooxygenase (COX)-expressing MSCs as a vital factor to maintain the intestinal mucosal barrier. We found that MSCs-induced organoid swelling through paracrine effect in vitro, a process due to enhanced water adsorption and is mediated by the COX-PGE2-EP4 axis. To further explore the regulatory effect of this axis on the intestinal epithelial barrier in vivo, we established the conditional knockout mouse model to specifically delete COX in MSCs and found that PGE2 reduction downregulated the gene Muc2 and induced a gastric metaplasia-like phenotype. Moreover, PGE2 defects increased the susceptibility of intestinal epithelium to colitis. Our study uncovers the paracrine signaling of COX-expressing MSCs in intestinal mucosal barrier maintenance, providing a basis for understanding the role of mesenchymal cells in the psychophysiology function of the intestine.
Project description:CpG 1826 binds to Toll-like receptor (TLR)9, whereas influenza virus PR8 activates pDC via TLR7. Differential stimulation of pDCs is expected to result in unique activation mechanism(s) leading to a different phenotypically and functionally matured pDC; We used microarrays to detail the global programme of gene expression underlying the maturation process of pDC activated with CpG 1826 and influenza virus PR8. We identified a distinct expression profile of upregulated immunomediators. Experiment Overall Design: Sorted pDCs were cultured for 1h and 4hs in medium control or with 5 µg/ml CpG 1826 or 300 HAU/ml purified influenza A/PR/8 virus. The first experiment (e1) included pDC in media and stimulated with CpG for 4h. In two other independent experimental batches (e2 and e3), we obtained samples of sorted pDC cultured in medium alone (med), and with CpG or PR8 (flu) for 1h and 4h. RNA extraction was performed using the RNeasy Kit (Qiagen) and hybridization on Affymetrix microarrays was performed using standard protocols. We sought to obtain homogeneous populations of pDCs at different time points under defined activation conditions in order to decipher the temporal resolution of expression profiles during the process of their maturation.
Project description:CpG 1826 binds to Toll-like receptor (TLR)9, whereas influenza virus PR8 activates pDC via TLR7. Differential stimulation of pDCs is expected to result in unique activation mechanism(s) leading to a different phenotypically and functionally matured pDC We used microarrays to detail the global programme of gene expression underlying the maturation process of pDC activated with CpG 1826 and influenza virus PR8. We identified a distinct expression profile of upregulated immunomediators. Keywords: time course