Gene expression analysis of mouse lymphatic endothelial cells (LECs) from the subcapsular sinus (SS, afferent) and lymphatic sinus (LS, efferent)
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ABSTRACT: Afferent lymphatic vessels bring antigens and diverse populations of leukocytes to draining lymph nodes, but efferent lymphatics allow only lymphocytes to leave the nodes. Despite fundamental importance of afferent vs. efferent lymphatics in immune response and cancer spread, molecular characteristics of these different arms of the lymphatic vasculature are largely unknown. In this work we report marked transcriptional differences between afferent and efferent lymphatic endothelial cells. Mouse inguinal, axillary, and brachial lymphnodes were collected and cryomolds prepared for laser-capture microdissection. Frozen sections were stained with various cell marker antibodies and micro-dissection performed to collect lymphatic endothelial cells. Total RNA was extracted from the cells and used in microarray analysis. Alternatively, popliteal, caudal, lumbar, inguinal, mesenteric, renal, axillary, brachial, deep and superficial cervical LN were enzymatically digested, the cells stained, and FACs sorted before RNA isolation.
Project description:Afferent lymphatic vessels bring antigens and diverse populations of leukocytes to draining lymph nodes, but efferent lymphatics allow only lymphocytes to leave the nodes. Despite fundamental importance of afferent vs. efferent lymphatics in immune response and cancer spread, molecular characteristics of these different arms of the lymphatic vasculature are largely unknown. In this work we report marked transcriptional differences between afferent and efferent lymphatic endothelial cells.
Project description: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. Experiment Overall Design: Global gene expression profile of normal dermal lymphatic endothelial cells cultured in media alone (no TNF) compared to that of normal dermal lymphatic endothelial cells stimulated with TNFalpha, 1 ng/ml for 48h.Triplicate biological samples were analyzed from human lymphatic endothelial cells (3 x controls; 3 x TNF treated) and a single sample analyzed from mouse lymphatic endothelial cells (1 x controls; 1 x TNF treated).
Project description: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. Keywords: TNFalpha, Lymphatic endothelium, induction, Inflammation
Project description:The lymphatic vasculature is critical for lung function, but defects in lymphatic functionin the pathogenesis of lung disease is understudied. To further assess the contribution of lymphatics to the pathogenesis of lung emphysema we used a mouse model of cigarette smoke (CS)-induced emphysema, and analyzed lung lymphatics using immunohistochemistry, functional assays, and confocal microscopy. Additionally, we further harvested thoracic lymph from CS-exposed mice for proteomic analysis. In this presented section of our research, we highlight the label free quantitative DIA proteomics approaches used to profile the proteomic and peptidomics changes in the lymph from cigarette smoke (CS)-mice as compared with the lymph proteome from mice exposed to room air. Label free quantitative DIA proteomics analysis of lymph confirmed upregulation of coagulation and inflammatory pathways in the lymphatics of CS-exposed mice compared to control mice.
Project description:Sphingosine 1-phosphate (S1P) influences T cell migration into and out of secondary lymphoid organs; however, its mechanism of action remains uncertain. Our previous research shows that agonism of the S1P receptor S1P1 inhibits the egress of T lymphocytes from the peripheral tissues into afferent lymphatics. To better define the mechanism of inhibition, we developed an in vitro model to characterize T cell transendothelial migration across lymphatics. Two commercially available endothelial cell lines (MS-1 and SVEC4-10) were characterized by flow cytometry, real time RT-PCR, and Affymetrix Gene Array. These cell lines were grown to confluent monolayers in transwell systems, on either the upper or lower surface of the transwell insert. T cells were isolated from the spleens of (C57BL/6 x C3H/HeJ)F1, S1P1 KO, or S1P1 KO littermate controls, and either treated with the S1P receptor modulator FTY720 or left untreated. Cells were migrated to chemokines (CCL19 or CCL21) for 4 hours, and migration quantified. Flow cytometry, RT-PCR, and array results identified MS-1 as a blood vascular endothelial cell line, expressing high levels of CD31, CD34, and ICAM-1 as well as other endothelial cell markers; while SVEC4-10 closely resemble a lymphatic phenotype, expressing LYVE-1, VEGFR-3, and podoplanin. T cells efficiently migrate across MS-1, whether grown on the upper or lower surface; whereas migration across SVEC4-10 only occurs when cells are grown on the lower surface of the transwell (iSVEC), recapitulating basal (abluminal) to apical (luminal) migration that occurs in vivo. FTY720 inhibits T cell migration across iSVEC, but not across MS-1. Inhibition is due to drug effects only on T cells but not endothelial cells. S1P1 KO T cells treated with FTY720 are not inhibited in their migration across the iSVEC line, showing that S1P1 stimulation is required for migration inhibition. The in vitro model developed here is the first to use endothelial cell lines to analyze the regulation of T cell migration across lymphatic endothelium. The results show there is directional control of T cell migration across lymphatic cells, such that T cells only migrate from a basal to apical direction. Agonism of S1P1 specifically inhibits migration, while absence of the receptor does not. These findings have important implications for the use of S1P1 agonists in transplantation, as inhibition of cell entry into afferent lymphatics and lymph nodes could impede the development of graft rejection. We used microarrays to detail the global gene expression of these two cell lines in order to beter determine their phenotype as blood vascular or lymphatic endothelial cell line for use in our newly-developed in vitro model. Experiment Overall Design: MS-1 or SVEC4-10 endothelial cell lines were grown in culture flasks for 3-5 days in standard culture medium (see protocol below) until reaching confluence. Cells were then gently dissociated from flask and cells were placed in Trizol reagent for RNA isolation.
Project description:The goal and objective of this study was to identify the transcriptional profiles differentiating the artery, vein, and lymphatic lineages in the adult rat vasculature with particular emphasis on the unique elements of the collecting lymphatic vessel transcriptome. A 2 x 3 experimental design was utilized in which parallel arteries, veins, and lymphatics from two different tissue beds were examined. The rat thoracic duct was selected as a large, post-nodal collecting lymphatic vessel that exhibits excellent conduit-type behavior while the rat mesenteric lymphatic was selected as a smaller, pre-nodal collecting lymphatic vessel that exhibits excellent pump behavior (see Gashev AA, et al. Microcirculation. 2004 Sep;11(6):477-92. [PMID: 15371129]). The axillary artery and vein were selected for comparison to the thoracic duct due to their similar anatomical position distal to the common junction of the lymphatic and venous vascular trees and represent a large artery and large vein, respectively. The mesentery artery and vein were selected for comparison to the mesenteric lymphatic vessels due to their parallel position within the mesenteric vasculature and represent a small atery and small vein, respectively.
Project description:Many modern vaccines use defined adjuvants to stimulate the innate immune system and shape the adaptive immune response. The exact nature of these innate signals and whether immune differentiation can originate within the periphery is not known. In the present study we used an ovine lymphatic cannulation model to characterise the cellular and transcriptomic profile of the afferent lymph following injection of a liposomal vaccine formulation incorporating diphtheria toxoid and the innate stimulator poly (I:C) over a 78 h period. The response to this vaccine featured an early activation of broad proinflammatory pathways (e.g. TLR signalling and inflammasome pathways) and the transient recruitment of granulocytes into the lymph. At 24hrs a more monocytic cellular profile arose coinciding with a transition to a specific antiviral response characterised by the up-regulation of genes associated with the receptors typical for the viral mimic, poly (I:C) (e.g. TLR3, RIG-I and MDA5). At the latest time points the up-regulation of IL-17A and IL-17F suggested that Th17 cells may participate in the earliest adaptive response to this vaccine. Together these data provide the most comprehensive picture of the cellular and molecular mechanisms that link the periphery to the draining lymph node following vaccination and indicate that the immune response is capable of specialising within the periphery. This study employed an ovine model of pseudoafferent lymphatic cannulation (see de Veer et al. 2010, Vaccine) to characterise the innate immune response within the afferent lymph to vaccination with liposomes+poly (I:C)+ diptheria toxoid. The sheep used in this study had both their pre-femoral lymph nodes removed at 1 year of age. Approximately 1 year after the lymph node removal, a second surgery was performed to insert a 0.96_0.58mm heparin-coated polyvinyl chloride cannula into the pseudoafferent (previous efferent) lymphatic duct of both sides. At least seven days were allowed for healing to occur after surgery before vaccinations were administered and experimental lymph samples were collected. Handling of animals and experimental procedures were all approved by the Monash University Animal Ethics Committee in accordance with the relevant licensing agreement. Vaccinations were injected subcutaneously in the area drained by the prefemoral lymph node. Afferent lymphatic samples were collected prior to vaccination as a control (PRE) and at 4-6, 26-28, 51-53 and 76-78 hours post vaccination with liposomes+poly (I:C)+ diptheria toxoid. Lymphocytes were removed from the afferent lymph using immunomagnetic separation. Next-generation sequencing was performed on RNA derived from the remaining innate immune cells. Samples from three sheep were used at all time points except 4-6 and 26-28 hours, where only two samples yielded sufficient RNA for sequencing.
Project description:The goal and objective of this study was to identify the transcriptional profiles differentiating the artery, vein, and lymphatic lineages in the adult rat vasculature with particular emphasis on the unique elements of the collecting lymphatic vessel transcriptome. A 2 x 3 experimental design was utilized in which parallel arteries, veins, and lymphatics from two different tissue beds were examined. The rat thoracic duct was selected as a large, post-nodal collecting lymphatic vessel that exhibits excellent conduit-type behavior while the rat mesenteric lymphatic was selected as a smaller, pre-nodal collecting lymphatic vessel that exhibits excellent pump behavior (see Gashev AA, et al. Microcirculation. 2004 Sep;11(6):477-92. [PMID: 15371129]). The axillary artery and vein were selected for comparison to the thoracic duct due to their similar anatomical position distal to the common junction of the lymphatic and venous vascular trees and represent a large artery and large vein, respectively. The mesentery artery and vein were selected for comparison to the mesenteric lymphatic vessels due to their parallel position within the mesenteric vasculature and represent a small atery and small vein, respectively. A 2 x 3, reference-based, experimental design was utilized consisting of both large (thoracic) and small (mesenteric) arteries, veins, and collecting lymphatic vessels for a total of 6 sample groups with n=6 biological replicates present in each group. All vessels acquired from the same donor animal have the same numerical label and were handled in parallel through all experimental steps. Each vessel sample RNA sample was amplified, labeled with Cy5, and compared to the same Rat Universal Reference RNA sample (Stratagene, La Jolla, CA) that was amplified and labeled with Cy3 dye. No dye swaps were utilized.
Project description:Abatacept is a recombinant CTLA-4 moleculed fused to a mutated human IgG molecule, which is clinically used in rheumatoid arthritis by inhibiting CD28-costimulation. This study aimed to inverstigate the ability of abatacept -mediated costimulation blockade to induce antigen-specific tolerance during primary immune responses. This is important as some studies have suggested that costimulation blockade can lead to CD4+ T cell anergy which could be beneficial for early therapy of autoimmune diseases such as rheumatoid arthritis. In addition we also investigated the effect that abatacept has on CD11c+ antigen presenting cells. This is important as costimulation blocakde can affect the biderectional interaction between CD4+ T cells and CD11c+ cells influencing the immunological outcome. We used microarrays to identify if abatacept treatment leads to antigen specific anergy using transgenic animals and models of priming and oral tolerance that established a synchronised monoclonal response. In addition this magnified the effect on the CD11c+ antigen presenting cells. This study included 5 experimental groups. DO11.10 RAG2-/- mice have CD4+ T cells specific for the ovalbumin (OVA) peptide OVA323-339. These mice were immunised with CFA/OVA s.c. (primed group) or tolerised by feeding with OVA (50mg/kg) in the drinking water. CD4+ cells were isolated 10 days post immunisation from draining lymph nodes (LNs) of unimmunised (pooled LNs and Spleen), orally tolerised (mesenteric LNs), primed (axillary LNs), primed treated with control IgG (axillary LNs) and primed treated with abatacept (axillary LNs). For CD11c+ cells cells were isolated by pooled secondary lymphoid organs (LNs and spleen).