Project description:Comparison of the transcriptional profiles of FV env-specific CD4 TCRbeta transgenic cells primed by an Ad5 vector with those primed by FV and submitted in E-MEXP-2950
Project description:CD4 T cell help is critical for both the generation and maintenance of germinal centers, and T follicular helper (TFH) cells are the CD4 T cell subset required for this process. SAP (SH2D1A) expression in CD4 T cells is essential for germinal center development. However, SAP-deficient mice have only a moderate defect in TFH differentiation as defined by common TFH surface markers. CXCR5+ TFH cells are found within the germinal center as well as along the boundary regions of T/B cell zones. Here we show that germinal center associated T cells (GC TFH) can be identified by their co-expression of CXCR5 and the GL7 epitope, allowing for phenotypic and functional analysis of TFH and GC TFH populations. Here we show GC TFH are a functionally discrete subset of further polarized TFH cells, with enhanced B cell help capacity and a specialized ability to produce IL-4 in a TH2-independent manner. Strikingly, SAP-deficient mice have an absence of the GC TFH subset and SAP- TFH are defective in IL-4 and IL-21 production. We further demonstrate that SLAM (Slamf1, CD150), a surface receptor that utilizes SAP signaling, is specifically required for IL-4 production by GC TFH. GC TFH cells require IL-4 and IL-21 production for optimal help to B cells. These data illustrate complexities of SAP-dependent SLAM family receptor signaling, revealing a prominent role for SLAM receptor ligation in IL-4 production by germinal center CD4 T cells but not in TFH and GC TFH differentiation. Analysis of in vivo antigen-specific (LCMV-specific, SMARTA TCR transgenic) WT and Sh2d1a-/- follicular helper CD4 T cells (CXCR5high),versus non-follicular helper CD4 T cells (CXCR5low), eight days after viral infection.
Project description:ABA regulates in plants a wide range of developmental events, mediates responses to environmental stress and is necessary to proceed through seed maturation and to acquire desiccation tolerance and dormancy. Immuno-modulation is a suitable means to study ABA functions during seed maturation. Anti-ABA single chain antibody was expressed in pea seed driving LeB4-promoter (Saalbach et al., High-level expression of a single chain Fv fragment (scFv) antibody in transgenic pea seeds J. Plant Physiol. 2001 158: 529-533), which produced only a weak phenotype with slightly decreased seed weight, globulin/albumin and total nitrogen content (aABA line 16 cultivar Erbi). In another approach with a stronger, improved USP-promoter used to express the anti-ABA antibody in pea seeds a different phenotype emerged (aABA line 7, cultivar Eifel). In this line individual seed weight increased by 20 to 30% together with higher globulin and albumin content. To dissect the aABA phenotype at the molecular level, a search for genes with differential expression patterns in transgenic plant versus wild type seeds has been performed using 6k-oligo microarray analysis. cDNA probes were prepared from RNA isolated from embryo of developing seeds of wild type (12, 18, and 22 DAP) and transgenic aABA plants (12, 18, and 22 DAP), which correspond to the transition phase of seed development, and 6k-oligo microarray.
Project description:Using 5 differents approaches, including RNA sequencing, we demonstrated that macrophages that specifically infiltrate renal tumors, express the immunosuppressive transcription factor Foxp3. Examination of the Foxp3 mRNA expression in 3 different cell subsets (including CD4 T cells (CD4), type-1 macrophages (M1) and type-2 macrophages (M2))
Project description:White clover mosaic virus (WCMV) is a major pathogen of white clover (Trifolium repens L.), with significant effects on yield and persistence. Due to the absence of natural sources of WCMV resistance a transgenic strategy has been employed to produce plants constitutively expressing WCMV replicase gene derivatives, designed to inhibit the propagation of WCMV through an RNA silencing mechanism. A 12,000 feature oligonucleotide microarray has been used to identify global changes in host plant, in addition to virus genome-encoded gene expression associated with WCMV infection in non-transgenic and transgenic WCMV-resistant white clover. Pairwise comparison between the transcriptome of mock-inoculated non-transgenic and WCMV-inoculated transgenic plants provides clear evidence for substantial equivalence between these two genotype/treatments, and demonstrate the efficacy of the transgenic strategy. WCMV- inoculated non-transgenic plants exhibit elevated abundance of many virus-encoded, and host immune response-specific transcripts compared to the transgenic resistant plants or mock-inoculated non-transgenic plants. By contrast, relative to inoculated sensitive plants, the majority of significantly up-regulated genes in mock-inoculated non-transgenic plants or WCMV-inoculated transgenic plants are markers of healthy cellular function. These results, and the occurrence of levels of WCMV-encoded transcripts in inoculated transgenic plants equivalent to those in virus-free plants, confirm the validity of the transgenic RNA silencing approach.<br>
Project description:Foxp3+ regulatory T cells (Treg cells) maintain immunological tolerance and their deficiency results in fatal multi-organ autoimmunity. Although heightened T cell receptor (TCR) signaling is critical for the differentiation of Treg cells, the role of TCR signaling in Treg cell function remains largely unknown. Here we demonstrate inducible ablation of the TCR results in Treg cell dysfunction which cannot be attributed to impaired Foxp3 expression, decreased expression of Treg cell signature genes or altered ability to sense and consume interleukin 2. Rather, TCR signaling was required for maintaining the expression of a limited subset of genes comprising 25% of the activated Treg cell transcriptional signature. Our results reveal a critical role for the TCR in Treg cell suppressor capacity. Array expression of Foxp3-CreERT2 CalphaFL/WT mice
Project description:The aim of this experiment is to determine microRNAs that are diffferentially regulated in allergic airway inflammation. MicroRNA expression profile between untreated and doxycycline treated CC10-IL13 bitransgenic mice