The exit of antigen-presenting cells (APC) and lymphocytes from inflamed skin to afferent lymph is vital for the initiation and maintenance of dermal immune responses. How such exit is achieved and how cells transmigrate the distinct endothelium of lymphatic vessels is however unknown. Here we show that inflammatory cytokines trigger activation of dermal lymphatic endothelial cells (LEC) leading to expression of the key leukocyte adhesion receptors ICAM-1, VCAM-1 and E-selectin, as well as a discrete panel of chemokines and other potential regulators of leukocyte transmigration. Furthermore, we show that both ICAM-1 and VCAM-1 are induced in the dermal lymphatic vessels of mice exposed to skin contact hypersensitivity where they mediate lymph node trafficking of DC via afferent lymphatics. Lastly, we show that TNF_-stimulates both DC adhesion and transmigration of dermal LEC monolayers in vitro and that the process is efficiently inhibited by ICAM-1 and VCAM-1 adhesion-blocking mAbs. These results reveal a CAM-mediated mechanism for recruiting leukocytes to the lymph nodes in inflammation and highlight the process of lymphatic transmigration as a potential new target for anti-inflammatory therapy.
An inflammation-induced mechanism for leukocyte transmigration across lymphatic vessel endothelium.
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View SamplesInvasion of lymphatic vessels is a key step in the metastasis of primary tumour cells to draining lymph nodes. Recent evidence indicates that such metastasis can be facilitated by tumour lymphangiogenesis, although it remains unclear whether this is a consequence of increased lymphatic vessel numbers or alteration in the properties of the vessels themselves. Here we have addressed this important question by comparing the RNA profile of normal dermal lymphatic endothelial cells (LEC) with those isolated from tumours of murine T-241/VEGF-C metastatic fibrosarcoma. Our findings reveal significant changes in the expression of some 792 genes in tumour lymphatics ( 2 fold up/downregulation, p 0.05), involving particularly transcripts associated with junctional adhesion, immunomodulation, extracellular matrix and vessel growth/patterning, several of which we have confirmed by RT-PCR and/or immunohistochemistry. Interestingly, this altered phenotype could not be attributed solely to VEGF-C induced lymphoproliferation, as no similar change in gene expression was reported when human LEC were cultured with VEGF-C in vitro. Moreover, we show that a key protein upregulated in the mouse model, namely the tight junction protein Endothelial Cell Specific Adhesion Molecule (ESAM), is similarly upregulated in tumour lymphatic vessels from 2/2 patients with head and neck squamous cell carcinoma and 4/4 patients with aggressive bladder carcinoma. These findings demonstrate a previously unrecognized influence of tumour environment on lymphatic gene expression and identify candidate tumour specific vessel markers that may prove valuable for either prognosis or therapy.
A novel gene expression profile in lymphatics associated with tumor growth and nodal metastasis.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Functional screening implicates miR-371-3p and peroxiredoxin 6 in reversible tolerance to cancer drugs.
Specimen part, Cell line, Treatment
View SamplesAcquired resistance to cancer drug therapies almost always occurs in advanced-stage patients even following a significant response to treatment. In addition to mutational mechanisms, various non-mutational resistance mechanisms have now been recognized. We previously described a chromatin-mediated subpopulation of reversibly drug-tolerant persisters (DTPs) that is dynamically maintained within a wide variety of tumor cell populations. Here, we explored a potential role for microRNAs in such transient drug tolerance. Functional screening of 879 human microRNAs revealed miR-371-3p as a potent suppressor of drug tolerance. PRDX6 (peroxiredoxin 6) was identified as a key target of miR-371-3p in establishing drug tolerance by regulating PLA2/PKC activity and reactive oxygen species. PRDX6 expression is associated with poor prognosis in cancers of multiple tissue origins. These findings implicate miR-371-3p as a suppressor of PRDX6 and suggest that co-targeting of PRDX6 or modulating miR-371-3p expression together with targeted cancer therapies may delay or prevent acquired drug resistance.
Functional screening implicates miR-371-3p and peroxiredoxin 6 in reversible tolerance to cancer drugs.
Cell line, Treatment
View SamplesWe sequenced mRNA from 12 samples extracted from mouse amygdala tissue to generate the first amygdala-specific murine transcriptome for germ-free mice (GF), conventionally raised controls (CON) and germ-free mice that have been colonized with normal microbiota from postnatal day 21 (exGF). Overall design: Equal amounts of RNA from two to three animals were pooled to yield 4 samples per group (CON, GF, and exGF). Pairwise comparisons for CONvsGF, CONvsexGF, GFvsexGF were performed using DESeq2.
Microbes & neurodevelopment--Absence of microbiota during early life increases activity-related transcriptional pathways in the amygdala.
No sample metadata fields
View SamplesAcquired resistance to cancer drug therapies almost always occurs in advanced-stage patients even following a significant response to treatment. In addition to mutational mechanisms, various non-mutational resistance mechanisms have now been recognized. We previously described a chromatin-mediated subpopulation of reversibly drug-tolerant persisters (DTPs) that is dynamically maintained within a wide variety of tumor cell populations. Here, we explored a potential role for microRNAs in such transient drug tolerance. Functional screening of 879 human microRNAs revealed miR-371-3p as a potent suppressor of drug tolerance. PRDX6 (peroxiredoxin 6) was identified as a key target of miR-371-3p in establishing drug tolerance by regulating PLA2/PKC activity and reactive oxygen species. PRDX6 expression is associated with poor prognosis in cancers of multiple tissue origins. These findings implicate miR-371-3p as a suppressor of PRDX6 and suggest that co-targeting of PRDX6 or modulating miR-371-3p expression together with targeted cancer therapies may delay or prevent acquired drug resistance.
Functional screening implicates miR-371-3p and peroxiredoxin 6 in reversible tolerance to cancer drugs.
Specimen part, Cell line, Treatment
View SamplesNon-tumor-reactive T cells are characterized by the inabilitzy to lyse autologous tumor cells, low to intermediate avidity TCRs and lack of NY-ESO-1 peptide tetramer binding. However most strikingly, non-tumor-reactive T cells are characterized by a molecular program associated with division arrest anergy with elevated expression of the inhibitory molecule p27kip1. This is accompanied by elevated expression of inhibitory molecules and reduced levels of transcription factors involved in T cell activation. Frequency analysis of the inhibited T cell population using the established molecular fingerprint as a novel biomarker might be applied for cancer vaccine development and optimization.
Cancer vaccine enhanced, non-tumor-reactive CD8(+) T cells exhibit a distinct molecular program associated with "division arrest anergy".
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View SamplesBased on studies in knockout mice, several inhibitory factors such as TGF-beta, IL-10, or CTLA-4 have been implicated as gate keepers of adaptive immune responses. Lack of these inhibitory molecules leads to massive inflammatory responses mainly mediated by activated T cells. In humans, the integration of these inhibitory signals for keeping T cells at a resting state is less well understood. To elucidate this regulatory network we assessed early genome-wide transcriptional changes during serum deprivation in human mature CD4+ T cells. The most striking observation was a "TGF-beta loss signature" defined by downregulation of many known TGF-beta target genes. Moreover, numerous novel TGF-beta target genes were identified that are under the suppressive control of TGF-beta. Expression of these genes was upregulated once TGF-beta signaling was lost during serum deprivation and again suppressed upon TGF-beta reconstitution. Constitutive TGF-beta signaling was corroborated by demonstrating phosphorylated SMAD2/3 in resting human CD4+ T cells in situ, which were dephosphorylated during serum deprivation and re-phosphorylated by minute amounts of TGF-beta. Loss of TGF-beta signaling was particularly important for T cell proliferation induced by low-level T cell receptor and costimulatory signals. We suggest TGF-beta to be the most prominent factor actively keeping human CD4+ T cells at a resting state.
Human resting CD4+ T cells are constitutively inhibited by TGF beta under steady-state conditions.
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View SamplesIncreased antigen cross-presentation but impaired cross-priming after activation of PPAR is mediated by up-regulation of B7H1
Increased antigen cross-presentation but impaired cross-priming after activation of peroxisome proliferator-activated receptor gamma is mediated by up-regulation of B7H1.
Specimen part
View SamplesDespite advances in contemporary chemotherapeutic strategies, long term survival still remains elusive for patients with metastatic colorectal cancer. A better understanding of the molecular markers of drug sensitivity to match therapy with patient is needed to improve clinical outcomes. In this study, we used in vitro drug sensitivity data from the NCI-60 cell lines together with their Affymetrix microarray data to develop a gene expression signature to predict sensitivity to oxaliplatin. In order to validate our oxaliplatin sensitivity signature, Patient-Derived Colorectal Cancer Explants (PDCCEs) were developed in NOD-SCID mice from resected human colorectal tumors. Analysis of gene expression profiles found similarities between the PDCCEs and their parental human tumors, suggesting their utility to study drug sensitivity in vivo. The oxaliplatin sensitivity signature was then validated in vivo with response data from 14 PDCCEs treated with oxaliplatin and was found to have an accuracy of 92.9% (Sensitivity=87.5%; Specificity=100%). Our findings suggest that PDCCEs can be a novel source to study drug sensitivity in colorectal cancer. Furthermore, genomic-based analysis has the potential to be incorporated into future strategies to optimize individual therapy for patients with metastatic colorectal cancer.
Characterization of an oxaliplatin sensitivity predictor in a preclinical murine model of colorectal cancer.
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