Project description:Recent studies have suggested that formation of supramolecular activation cluster (SMAC), a large ‘immunological synapse’ composed of various signaling complexes, enhances CD4+ T cell activation. Critically, although the composition of SMAC is known, the proteins involved in SMAC formation have not been fully investigated. We identified that intraflagellar transport 20 (IFT20) play central roles in the effector functino of CD4+ T cells.
Project description:Human FOXP3+CD25+CD4+ regulatory T cells (Tregs) play a dominant role in the maintenance of immune homeostasis. Several genes are known to be important for murine Tregs, but for human Tregs the genes and underlying molecular networks controlling the suppressor function still largely remain unclear. We here performed a high-time-resolution dynamic analysis of the transcriptome during the very early phase of human Treg/ CD4+ T-effector cell activation. After constructing a correlation network specific for Tregs based on these dynamic data, we described a strategy to identify key genes by directly analyzing the constructed undirected correlation network. Six out of the top 10 ranked key hubs are known to be important for Treg function or involved in autoimmune diseases. Surprisingly, PLAU (the plasminogen activator urokinase) was among the 4 new key hubs. We here show that PLAU was critical for expression regulation of FOXP3, EOS and several other important Treg genes and the suppressor function of human Tregs. Moreover, we found Plau inhibits murine Treg development and but promotes the suppressive function. Further analysis unveils that PLAU is particularly important for memory Tregs and that PLAU mediates Treg suppressor function via STAT5 and ERK signaling pathways. Our study shows the potential for identifying novel key genes for complex dynamic biological processes using a network strategy based on high-time-resolution data, and highlights a critical role of PLAU in both human and murine Tregs. The construction of a dynamic correlation network of human Tregs provides a useful resource for the understanding of Treg function and human autoimmune diseases. The high-time-resolution time-series transcriptomic data during the very early phase of human Treg/Teff activation could be generally used for further mechanistic analysis of human Treg function. These data could be further used for biological network analysis, dynamic analysis, modeling by experimental researchers, bioinformaticians, computational biologists and systems biologists. We have measured the genome-wide expression of 38,500 genes (probes) by performing a high-time-resolution time-series analysis during the activation process of human regulatory T cells /CD4+ T-effector cells at 19 time points for the first 6h with an equal interval of 20 min. We have also overexpressed the GARP gene in human effector T cells and measured the genome-scale expression for the GARP-overexpressed cells and ThGFP cells at time point 0, 100 and 360min following activation. The stimulation source used in this work is a combination of anti-CD3/-CD28 Dynal beads with IL2 100U/ml.
Project description:Crohn’s disease (CD) is one of the major forms of inflammatory bowel disease (IBD), characterized by chronic inflammation of the gastrointestinal tract. CD is associated with aberrant Th1 and Th17 responses accompanied by high levels of IFN-g and IL-17, respectively. Protein kinase 2 (CK2) is a highly conserved serine-threonine kinase that is involved in several signal transduction pathways which regulate inflammatory responses. CK2 promotes Th17 cell differentiation and suppresses the generation of Foxp3+ regulatory T cells. The function of CK2 in CD4+ T-cells during the pathogenesis of CD is unknown. We utilized T-cell induced colitis model, transferring CD45RBhi naïve CD4+ T-cells from CK2afl/fl littermate control and CK2afl/fldLck-Cre mice into Rag1-/- mice. We demonstrate that CD4+ T-cells from CK2afl/fldLck-Cre mice fail to induce wasting disease and significant intestinal inflammation, which is associated with decreased IL-17A+, IFN-g+ and double positive IL-17A+ IFN-g+ CD4+ T-cells in the spleen and colon. Further, we determine that CK2a regulates CD4+ T-cell proliferation through a cell-intrinsic manner. CK2a is also important in controlling CD4+ T-cell responses by regulating NFAT2, which is vital for T-cell activation and proliferation. Thus, our data demonstrate that CK2a contributes to the pathogenesis of colitis by promoting CD4+ T-cell proliferation and Th1 and Th17 responses, and that targeting CK2 kinase activity may be a novel therapeutic treatment for CD patients.
Project description:Identifying BTLA interacting proteins in mouse CD4+ effector T cells expressing BTLA at endogenous levels and after stimulation with pervanadate.
Project description:Wodarz2007 - HIV/CD4 T-cell interaction
A deterministic model illustrating how
CD4 T-cells can influence HIV infection.
This model is described in the article:
Infection dynamics in
HIV-specific CD4 T cells: does a CD4 T cell boost benefit the
host or the virus?
Wodarz D, Hamer DH.
Math Biosci 2007 Sep; 209(1):
14-29
Abstract:
Recent experimental data have shown that HIV-specific CD4 T
cells provide a very important target for HIV replication. We
use mathematical models to explore the effect of specific CD4 T
cell infection on the dynamics of virus spread and immune
responses. Infected CD4 T cells can provide antigen for their
own stimulation. We show that such autocatalytic cell division
can significantly enhance virus spread, and can also provide an
additional reservoir for virus persistence during anti-viral
drug therapy. In addition, the initial number of HIV-specific
CD4 T cells is an important determinant of acute infection
dynamics. A high initial number of HIV-specific CD4 T cells can
lead to a sudden and fast drop of the population of
HIV-specific CD4 T cells which results quickly in their
extinction. On the other hand, a low initial number of
HIV-specific CD4 T cells can lead to a prolonged persistence of
HIV-specific CD4 T cell help at higher levels. The model
suggests that boosting the population of HIV-specific CD4 T
cells can increase the amount of virus-induced immune
impairment, lead to less efficient anti-viral effector
responses, and thus speed up disease progression, especially if
effector responses such as CTL have not been sufficiently
boosted at the same time.
This model is hosted on
BioModels Database
and identified by:
BIOMD0000000663.
To cite BioModels Database, please use:
Chelliah V et al. BioModels: ten-year
anniversary. Nucl. Acids Res. 2015, 43(Database
issue):D542-8.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
Project description:Tumours progress despite being infiltrated by effector T cells. Tumour necrosis is associated with poor survival in a variety of cancers. Here, we report that that necrosis causes release of an intracellular ion, potassium, into the extracellular fluid of human and mouse tumours. Surprisingly, elevated extracellular potassium ([K+]e) was sufficient to profoundly suppress mouse and human T cell anti-tumour function. Elevations in [K+]e acted to acutely impair T cell receptor (TCR) dependent Akt-mTOR phosphorylation and effector function. Potassium mediated suppression of Akt-mTOR signalling and T cell effector function required intact activity of PP2A, a serine/threonine phosphatase. The suppressive effect mediated by elevated [K+]e required a T cell-intrinsic increase in intracellular potassium ([K+]i) and was independent of changes in plasma membrane potential (Vm). Finally, ionic reprogramming of tumour-specific T cells via over-expression of the voltage-gated potassium channel Kv1.3 lowered [K+]i and improved effector functions in vitro and in vivo, with this gain of function being dependent on intact channel function. Consequently, Kv1.3 T cell expression enhanced tumour clearance and the survival of melanoma-bearing mice. These results uncover a previously undescribed ionic checkpoint against T cell function within tumours and identify new strategies for cancer immunotherapy. RNA expression was measured by RNA-Seq on day 5 of cultures, maintained in individual biologial triplicates which were stimulated with immobilized anti-CD3/28 antibodies or kept in complete media (no stim) - with equivalent conditions treated with isotonic media containing elevated potassium.
Project description:In response to acute infection CD8 T cells differentiate into effector cells capable of clearing the antigen. While the transcriptional and functional changes have previously been studied little is known of the epigenetic modifications that accompany this differentiation process. To gain insights into CD8 T cell effector differentiation and the role of epigenetics, we mapped DNA methylation by MeDIP-seq in naive CD8 T cells and day 8 effector CD8 T cells that are induced following an acute infection. We identified hundreds of thousands of differentially methylated regions (DMRs). Promoter DNA methylation inversely correlated with gene expression and DMRs were enriched for functional transcription factor binding sites. These data indicated that DNA methylation is dynamic during CD8 T cell differentiation and provide a map of possible regulatory regions important in this process. Examination of DNA methylation during CD8 T cell differentiation from naïve to day 8 effectors following acute infection