Project description:CD40L and IL-21 are major contributors to the transcriptional emergency of PC identify genes in committed B cells. In order to decipher specific CD40L- and IL21-targeted genes, fresly purified human tonsil centroblasts (n=6) were cultured for 3 hours in presence or not of CD40L and IL-21 before transciptome analysis were performed.
Project description:Chronic Lymphocytic Leukemia (CLL) cells multiply in secondary lymphoid tissue but the mechanisms leading to their proliferation are still uncertain. In addition to BCR-triggered signals, other microenvironmental factors might well be involved. In proliferation centres, leukemic B cells are in close contact with CD4+CD40L+ T cells. Therefore, we here dissected the signals provided by autologous activated T cells (Tact) to CLL cells. Although the gene expression profile induced by Tact was highly similar to that induced by sole CD40 signaling, an obvious difference was that Tact induced proliferation of CLL cells. We determined that stimulation with only CD40L+IL-21 was sufficient to induce robust proliferation in CLL cells. We then defined an IL-21-induced gene signature in CLL, containing components of JAK-STAT and apoptosis pathways, and this signature could be detected in lymph node (LN) samples from patients. Finally, we could detect IL-21 RNA and protein in LN, and IL-21 production ex vivo by LN CD4+CXCR5+ follicular helper T cells. These results indicate that, in addition to BCR signaling, activated T cells might contribute to CLL cell proliferation via CD40 and IL-21. Targeting these signaling pathways might offer new venues for treatment of CLL.
Project description:Chronic Lymphocytic Leukemia (CLL) cells multiply in secondary lymphoid tissue but the mechanisms leading to their proliferation are still uncertain. In addition to BCR-triggered signals, other microenvironmental factors might well be involved. In proliferation centres, leukemic B cells are in close contact with CD4+CD40L+ T cells. Therefore, we here dissected the signals provided by autologous activated T cells (Tact) to CLL cells. Although the gene expression profile induced by Tact was highly similar to that induced by sole CD40 signaling, an obvious difference was that Tact induced proliferation of CLL cells. We determined that stimulation with only CD40L+IL-21 was sufficient to induce robust proliferation in CLL cells. We then defined an IL-21-induced gene signature in CLL, containing components of JAK-STAT and apoptosis pathways, and this signature could be detected in lymph node (LN) samples from patients. Finally, we could detect IL-21 RNA and protein in LN, and IL-21 production ex vivo by LN CD4+CXCR5+ follicular helper T cells. These results indicate that, in addition to BCR signaling, activated T cells might contribute to CLL cell proliferation via CD40 and IL-21. Targeting these signaling pathways might offer new venues for treatment of CLL. CLL cells were cultured under different conditions for 16 hours and then sorted to purity as CD20+ CD5+ cells.
Project description:IL-21 induces B cell activation, and differentiation into antibody-secreting plasmablasts in vitro. This process is abolished by loss-of function mutations in STAT3 We used microarrays to identify genes that are induced by IL-21 in a STAT3-dependent manner Sort-purified naïve B cells from four healthy donors and three patients with AD-HIES due to heterozygous STAT3 mutations were cultured for four days with CD40L in the presence or absence of IL-21 (50ng/ml). After four days, RNA was extracted from the harvested cells and the genetic profile was analysed by microarray.
Project description:Atherosclerosis, the underlying vascular cause of cardiovascular disease, has a strong inflammatory component. The co-stimulatory CD40-CD40 ligand (CD40L) signaling axis is a pivotal regulator of immune responses in atherosclerosis. However, therapeutic long-term inhibition of CD40L will severely compromise the immune system making it a non-viable treatment option. To circumvent this issue, cell-specific inhibition may present a better approach to target the CD40-CD40L axis. Therefore, we generated T cell and platelet-specific knockout mice for CD40L and apolipoprotein E, which were aged for 28 weeks to study their effects on immune status and atherosclerosis. Here, we show that T cell specific deficiency in CD40L signaling reduced plaque progression through hampered Th1 polarization as well as reduced antigen-dependent proliferation and oxLDL IgM production. DC-specific CD40 deficient mice displayed a similar phenotype. Platelet-specific CD40L deficiency, however, failed to decrease atherosclerosis, but ameliorated atherothrombosis. Together, our results illuminate the divergent cell-specific mechanisms of CD40-CD40L signaling in atherosclerosis, which may lead to advances in targeted therapies.
Project description:To assess the nature of CD8+CD40L+ memory Tcells, we compared the gene expression to CD8+CD40L- and CD4+ counterparts, and found similarities in expression of genes encoding cytokines PBMCs were isolated from five healthy donors. The cells were stimulated with PMA/Ionomycin for 6 h, and subsequently sorted into the CD4+CD45RA-CD40L+, CD8+CD45RA-CD40L-, CD8+CD45RA-CD40L+ populations by FACS-sort
Project description:To assess the nature of CD8+CD40L+ memory Tcells, we compared the gene expression to CD8+CD40L- and CD4+ counterparts, and found similarities in expression of genes encoding cytokines. PBMCs were isolated from five healthy donors. The cells were stimulated with PMA/Ionomycin for 6 h, and subsequently sorted into the CD4+CD45RA-CD40L+, CD8+CD45RA-CD40L-, CD8+CD45RA-CD40L+ populations by FACS-sort.
Project description:To investigate miRNA expression in human tonsil squamous cell carcinoma (SCC) compared to normal tonsil tissue. Two colour LNA Exiqon array. MicroRNAs were labeled at 3'-end with a P-CU-C3-Cy3 RNA linker. A mixture of 371 synthetic DNA reference oligonucleotides containing complementary sequences to all LNA probes was randomly labeled using the ULYSIS labeling kit.