Project description:Sphingosine 1-phosphate (S1P), a lipid chemoattractant, guides immune cells from the low-S1P environment of tissues into the high-S1P environment of circulatory fluids. Most notably, S1P directs T cell exit from lymph nodes (LN), where T cells are initially activated to fight pathogens, into lymph, from which T cells flow into blood and ultimately reach inflamed tissues. T cells follow these gradients primarily using S1P receptor 1 (S1PR1). The drugs Gilenya and Siponimod, both FDA-approved for the autoimmune disease multiple sclerosis, target S1PR1. They blind self-reactive T cells to S1P gradients, block them from exiting LN, and thus prevent them from infiltrating the central nervous system. While recent work has revealed key aspects of how S1P gradients are established at steady-state, very little is known about S1P distribution in disease, and in turn how changing S1P gradients may affect the immune response. Here, we find that LN S1P increases during an immune response, which prolongs the time T cells spend in the LN before exiting into lymph. Inflammatory monocytes, which had not previously been implicated in shaping S1P gradients, are an important source of this S1P. Inflammatory monocytes must express the early activation marker CD69 to supply S1P to T cells; CD69 represses transcription of S1P receptor 5 (S1pr5), enabling monocytes to infiltrate the LN T zone and efficiently release S1P. Here we compared RNA sequencing of inflammatory monocytes WT or CD69-KO infiltrating the draining lymph node.$
Project description:In this study we focussed our investigations on ECM remodelling by FRCs during lymph node (LN) expansion, and the interconnection between the cellular and ECM components of the conduit network. We demonstrate a loss of ECM components of the conduit during acute LN expansion
Project description:Evolution of melanoma from a primary tumor to widespread metastasis is crucially dependent on lymphatic spread. The mechanisms regulating the initial step in metastatic dissemination via regional lymph nodes remain largely unknown. We have previously described a dysfunctional immune profile that precedes evidence of metastasis in the first node draining from the primary tumor, the sentinel lymph node (SLN). Herein, we explore the role of melanoma-derived extracellular vesicles (EVs) as mediators of this pre-metastatic niche through cargo-specific polarization of dendritic cells (DCs). Utilizing mass cytometry, pre-metastatic SLNs demonstrate compromised co-stimulatory CD80 expression compared to healthy lymph nodes. Similarly, DCs matured in vitro in the presence of melanoma EVs showed impaired co-stimulation and polarization towards a chronic inflammatory cytokine milieu. Profiling of melanoma EV cargo identified shared proteomic and RNA signatures including the signaling axis S100A8, S100A9 and cognate receptor TLR4. Mechanistically, S100A8 and S100A9 compromised DC maturation, a phenotype which was partially recovered following TLR4 blockade. Early evidence demonstrates similar EVs can be isolated from human afferent lymphatic fluid ex vivo. Taken together, we propose synergistic interactions among melanoma EV cargo are responsible for suppressing DC maturation, potentially explaining the survival of malignant melanocytes metastasizing into seemingly “normal” regional lymph nodes.
Project description:A classifier was build on 82 training samples to differentiate between lymph node negative (N0) and lymph node metastasis (N+) head and neck squamous-cell carcinomas (HNSCC). The 102 predictor genes that resulted from this classifier where then validated against a independent validation set.
Project description:To determine the different gene signatures between B lymphocytes from tumor draining lymph node (DLN) and normal lymph node (NLN), we have employed gene microarray as a discovery platform to identify gene signatures of tumor-educated B cells in DLN from tumor-bearing mice, taking NLN from normal mice as a control. We subcutaneously inoculated Balb/c mice with breast cancer cell line 4T1. Two weeks later, DLN was harvest and B cells were purified as descript in “treatment protocol”. From gene microarray, we found that B cells in DLN showed quite different transcript profiles from that in NLN.
Project description:This SuperSeries is composed of the following subset Series: GSE29152: Lymph node stromal cells: Control siRNA treated vs. Eif4g3 siRNA treated GSE29153: Differential gene expression in the Pancreatic lymph node of Deaf1 knockout mice vs. wild type littermate controls Refer to individual Series
Project description:Lymph node involvement is a major prognostic variable in breast cancer. Whether the molecular mechanisms that drive breast cancer cells to colonize lymph nodes are shared with their capacity to form distant metastases is yet to be established. In a transcriptomic survey aimed at identifying molecular factors associated with lymph node involvement of ductal breast cancer, we found that luminal differentiation, assessed by the expression of estrogen receptor (ER) and/or progesterone receptor (PR) and GATA3, was only infrequently lost in node-positive primary tumors and in matched lymph node metastases. The transcription factor GATA3 critically determines luminal lineage specification of mammary epithelium and is widely considered a tumor and metastasis suppressor in breast cancer. Strong expression of GATA3 and ER in a majority of primary node-positive ductal breast cancer was corroborated by quantitative RT-PCR and immunohistochemistry in the initial sample set, and by immunohistochemistry in an additional set from 167 patients diagnosed of node-negative and positive primary infiltrating ductal breast cancer, including 102 samples from loco-regional lymph node metastases matched to their primary tumors, as well as 37 distant metastases. These observations suggest that loss of luminal differentiation is not a major factor driving the ability of breast cancer cells to colonize regional lymph nodes. The transcriptomic study comprises 16 samples from Lymph node metastasis from infiltrating ductal breast carcinoma, 18 samples from Primary node-positive infiltrating ductal,7 samples from Primary node-negative infiltrating ductal and 3 samples from Unaffected lymph node were included. Their RNA was isolated and prepared for hybridization to human Affymetrix GeneChip arrays.
Project description: Lymph node involvement is a major prognostic variable in breast cancer. Whether the molecular mechanisms that drive breast cancer cells to colonize lymph nodes are shared with their capacity to form distant metastases is yet to be established. In a transcriptomic survey aimed at identifying molecular factors associated with lymph node involvement of ductal breast cancer, we found that luminal differentiation, assessed by the expression of estrogen receptor (ER) and/or progesterone receptor (PR) and GATA3, was only infrequently lost in node-positive primary tumors and in matched lymph node metastases. The transcription factor GATA3 critically determines luminal lineage specification of mammary epithelium and is widely considered a tumor and metastasis suppressor in breast cancer. Strong expression of GATA3 and ER in a majority of primary node-positive ductal breast cancer was corroborated by quantitative RT-PCR and immunohistochemistry in the initial sample set, and by immunohistochemistry in an additional set from 167 patients diagnosed of node-negative and –positive primary infiltrating ductal breast cancer, including 102 samples from loco-regional lymph node metastases matched to their primary tumors, as well as 37 distant metastases. These observations suggest that loss of luminal differentiation is not a major factor driving the ability of breast cancer cells to colonize regional lymph nodes.