Project description:Endobronchial ultrasound (EBUS) guided biopsy is becoming the mainstay for investigation of mediastinal lymphadenopathy to aid laboratory diagnosis of malignancy, sarcoidosis or tuberculosis. However, diagnostic uncertainty is still common in the distinction between culture negative tuberculosis and sarcoidosis or malignancy and reactive lymphadenitis. We sought to evaluate the role of genome-wide transcriptional profiling of EBUS guided lymph node samples to aid diagnostic processes in this setting.
Project description:The immune-suppressive features often possessed by invasive tumors hamper effective anti-tumor immunity. In this context, tumor-infiltrating regulatory T cells (Tregs) have been widely implied, principally as unwanted suppressors of anti-tumor immune responses. However, while many studies have focused on tumor-infiltrating Tregs, the function and signaling of Tregs in tumor-associated lymph nodes is largely unknown. In this study, we set out to clarify how immune signaling in lymph nodes is impacted by its contact to the tumour. Because muscle-invasive urothelial bladder cancer (MIBC) represent an immunogenic cancer were Tregs are accumulated and sentinel nodes (SNs) can be efficiently detected, we explored the protein expression of T-cells in SNs and non-SNs of MIBC patients. Proteomic analysis of Tregs and effector T-cells in SN and non-draining lymph nodes found SN-Tregs in MIBC patients to up-regulate growth and immune signaling pathways, the cytokine IL-16 being central in the signaling network. Experimental validation showed that in Tregs, tumoral factors increase IL-16 processing into bioactive forms and increase FOXP3 expression. In conclusion, altered IL-16 processing caused by tumour-released factors stimulate expansion of SN-Tregs in MIBC, creating an immunosuppressive environment and contributing to immune escape.
Project description:To characterize patterns of global transcriptional deregulation in primary colon carcinomas, we did gene expression profiling of 73 tumors [Unio Internationale Contra Cancrum stage II (n = 33) and stage III (n = 40)] using oligonucleotide microarrays. For 30 of the tumors, expression profiles were compared with those from matched normal mucosa samples. We identified a set of 1,950 genes with highly significant deregulation between tumors and mucosa samples (P < 1e-7). A significant proportion of these genes mapped to chromosome 20 (P = 0.01). Seventeen genes had a >5-fold average expression difference between normal colon mucosa and carcinomas, including up-regulation of MYC and of HMGA1, a putative oncogene. Furthermore, we identified 68 genes that were significantly differentially expressed between lymph node-negative and lymph node-positive tumors (P < 0.001), the functional annotation of which revealed a preponderance of genes that play a role in cellular immune response and surveillance. The microarray-derived gene expression levels of 20 deregulated genes were validated using quantitative real-time reverse transcription-PCR in >40 tumor and normal mucosa samples with good concor- dance between the techniques. Finally, we established a relationship between specific genomic imbalances, which were mapped for 32 of the analyzed colon tumors by comparative genomic hybridization, and alterations of global transcriptional activity. Previously, we had conducted a similar analysis of primary rectal carcinomas. The systematic comparison of colon and rectal carcinomas revealed a signif- icant overlap of genomic imbalances and transcriptional deregulation, including activation of the Wnt/B-catenin signaling cascade, suggesting similar pathogenic pathways. [Cancer Res 2007;67(1):41-56] Samples of tumor and/or mucosa from a total of 65 colon cancer patients, i.e. 103 arrays
Project description:Gene expression in the the pancreatic lymph node of 4, 12, and 30 week old Deaf1-knockout (KO) mice compared to BALB/c littermate controls. Gene expression was measured in the pancreatic lymph nodes of 4 wk old Deaf1 KO mice (2 replicates), 12 wk old Deaf1-KO mice (3 replicates), and 30 wk old Deaf1-KO mice (3 replicates).
Project description:High endothelial venules (HEVs) play a crucial role in adaptive immune responses in secondary lymphoid organs (SLOs). They are uniquely equipped with high levels of peripheral node addressins (PNAd), harboring carbohydrate structures that serve as L-Selectin ligands to efficiently facilitate lymphocyte homing. During inflammation, the HEV network expands in SLOs, increasing lymphocyte infiltration, but the underlying mechanisms maintaining HEVs remain underexplored. Here, we report that autophagy is essential for HEV function and expansion. Using mass spectrometry, and an inducible HEV tracer system in mice, we demonstrate that autophagy deficiency compromises LTR-signaling and the unfolded protein response in HEVs, leading to disrupted PNAd production, dedifferentiation, and reduced lymphocyte homing.Our work uncovers an unprecedented role of autophagy in safeguarding HEV identity and function during inflammation.