Project description:Our data suggest that peptide-presenting DC receive signals from synapse-forming antigen specific CD4+ or CD8+ T cells that alter the DC expression profile. To further test this notion, we hock immunized T cell-engrafted mice with NP harboring CpG and coated with OVA (OVA / CpG NP) or the control antigen BSA (BSA / CpG NP) and isolated NP+ DC for RNAseq.
Project description:The interaction of natural killer (NK) cells with dendritic cells (DC) results in reciprocal cell activation through the interaction of membrane proteins and the release of soluble factors. Here we report that in NK-DC cocultures, among a set of 84 cytokines investigated, activin A was the second highest induced gene, with CXCL8 being the most upregulated one. Activin A is a member of the TGF-M-NM-2 superfamily and was previously shown to possess both pro- and antiinflammatory activities. In NK-DC cocultures, the induction of activin A required cell contact and was dependent on the presence of proinflammatory cytokines (i.e. IFN-M-NM-3, TNF-M-NM-1 and GM-CSF) as well as on NK cell-mediated DC killing. CD1+ DC were the main activin A producer cells among myeloid blood DC subsets. In NK-DC cocultures, inhibition of acitivn A by follistatin, a natural inhibitory protein, or by a specific blocking antibody, resulted in the upregulation of proinflammatory cytokine release (i.e. IL-6, IL-8, TNF-M-NM-1) by DC and in the increase of DC maturation. In conclusion, our study reports that activin A, produced during NK-DC interactions, represents a relevant negative feedback mechanism that might function to prevent excessive immune activation by DC. Human CD14 positive monocytes were differentiated to DC in vitro in the presence of IL-4 (20 ng/ml) and GM-CSF (50 ng/ml) for 6 days. Immature DC were then cocultured with allogeneic IL-15-activated NK cells (at 1:1 NK:DC ratio) for 0, 2 and 6 hrs. RNA was obtained from three independent coculture experiments. Equal amount of total RNA from each experiment was pooled prior to gene expression analysis. The gene expression of common cytokines was quantified using an RT2 Profiler PCR Array (Qiagen).
Project description:The interaction of natural killer (NK) cells with dendritic cells (DC) results in reciprocal cell activation through the interaction of membrane proteins and the release of soluble factors. Here we report that in NK-DC cocultures, among a set of 84 cytokines investigated, activin A was the second highest induced gene, with CXCL8 being the most upregulated one. Activin A is a member of the TGF-β superfamily and was previously shown to possess both pro- and antiinflammatory activities. In NK-DC cocultures, the induction of activin A required cell contact and was dependent on the presence of proinflammatory cytokines (i.e. IFN-γ, TNF-α and GM-CSF) as well as on NK cell-mediated DC killing. CD1+ DC were the main activin A producer cells among myeloid blood DC subsets. In NK-DC cocultures, inhibition of acitivn A by follistatin, a natural inhibitory protein, or by a specific blocking antibody, resulted in the upregulation of proinflammatory cytokine release (i.e. IL-6, IL-8, TNF-α) by DC and in the increase of DC maturation. In conclusion, our study reports that activin A, produced during NK-DC interactions, represents a relevant negative feedback mechanism that might function to prevent excessive immune activation by DC.
Project description:TDC are an hematopoietic cell subset identified and characterized by Mirela Kuka, Ivana Munitic and Jonathan D. Ashwell (Kuka et al., 2012, Nat Commun). TDC combine dendritic cell (DC) and conventional ab T cell markers and functional properties. Such duality might render TDC particularly responsive to infectious organisms, because they can bridge innate and adaptive traits. This novel cell subset substantially differs from other known innate T cells in many ways: they undergo an antigen-specific selection process indistinguishable from classical ab cells, they can proliferate in response to cognate antigens, and they lack markers of NKT or gd T cells. The expression data found in this dataset confirm that TDC have a genetic signature distinct from that of classical DC or of conventional T cells. This distinct genetic profile identifies them as a separate cell type and raises the possibility that TDC may have functions other than those of T and DC.
Project description:Microglia, the parenchymal brain macrophages of the central nervous system (CNS), have emerged as critical players in brain development and homeostasis. Immune functions of these cells, however, remain less well defined. We investigated contributions of microglia in a relapsing remitting (RR) multiple sclerosis paradigm, experimental autoimmune encephalitis (RR-EAE) in C57BL/6 / SJL F1 mice. Fate mapping-assisted translatome profiling during the RR disease course revealed the potential of microglia to interact with T cells through antigen presentation, co-stimulation, and co-inhibition. Abundant microglia - T cell aggregates, as observed by histology and flow cytometry, supported the notion of functional interactions of microglia and T cells during remission, with a bias towards T regulatory cells. Finally, microglia_x0002_restricted Ifng receptor and MHC mutagenesis significantly affected the functionality of the regulatory T cell compartment in the diseased CNS and remission. Collectively, our data establish critical non-redundant cognate and cytokine-mediated interactions of microglia with CD4+ T cells during autoimmune neuro-inflammation.
Project description:Analyze condensin binding by fluorescence recovery after photobleaching (FRAP) and chromatin immunoprecipitation followed by sequencing (ChIP-seq) in ATP hydrolysis mutant and in mutants that affect the level of histone H4K20 methylation and H4K16ac enrichment and depletion on the X chromosome. We have also performed Hi-C analysis to test how 3D DNA interactions mediated by condensin DC change in the catalytic and null mutant of dpy-21, a H4K20me2 demethylase that increase H4K20me1 on the X.
Project description:analyze condensin binding by fluorescence recovery after photobleaching (FRAP) and chromatin immunoprecipitation followed by sequencing (ChIP-seq) in ATP hydrolysis mutant and in mutants that affect the level of histone H4K20 methylation and H4K16ac enrichment and depletion on the X chromosome. We have also performed Hi-C analysis to test how 3D DNA interactions mediated by condensin DC change in the catalytic and null mutant of dpy-21, a H4K20me2 demethylase that increase H4K20me1 on the X.