Project description:B cells, like T cells, can infiltrate sites of inflammation, but the processes and B cell subsets involved are poorly understood. Using human cells and in vitro assays, we find only a very small number of B cells will adhere to TNF-activated (but not to resting) human microvascular endothelial cells (ECs) under conditions of venular flow and do so by binding to ICAM-1 and VCAM-1. CXCL13 and to a lesser extent CXCL10 bound to the ECs can increase adhesion and induce transendothelial migration (TEM) of adherent naïve and memory B cells in 10-15 minutes through a process involving cell spreading, translocation of the microtubule organizing center (MTOC) into a trailing uropod and interacting with EC ALCAM. Engagement of the BCR by EC-bound anti-κ light chain antibody also increases adhesion and TEM of κ+ but not λ+ B cells. BCR-induced TEM takes 30-60 minutes, requires Syk activation, is initiated by B cell rounding up and translocation of the MTOC to the region of the B cell adjacent to the EC and also utilizes EC ALCAM for TEM. BCR engagement reduces the number of B cells responding to chemokines and preferentially stimulates TEM of CD27+ B cells that co-express IgD, with or without IgM, as well as CD43. RNA Seq analysis suggests peripheral blood CD19+CD27+CD43+IgD+ cells have increased expression of genes that support BCR activation as well as innate immune properties in comparison to total peripheral blood CD19+ cells.
Project description:Metastatic colonization involves cancer cell lodgment or adherence in the microvasculature and subsequent migration of those cells across the endothelium into a secondary organ site. To study this process further, we analyzed transendothelial migration of human PC-3 prostate cancer cells in vitro. We isolated a subpopulation of cells, TEM4-18, that crossed an endothelial barrier more efficiently, but surprisingly, were less invasive than parental PC-3 cells in other contexts in vitro. Importantly, TEM4-18 cells were more aggressive than PC-3 cells in a murine metastatic colonization model. Microarray and FACS analysis of these cells showed that the expression of many genes previously associated with leukocyte trafficking and cancer cell extravasation were either unchanged or down-regulated. TEM4-18 cells exhibited characteristic molecular markers of an epithelial-to-mesenchymal transition (EMT), including frank loss of E-cadherin expression and upregulation of the E-cadherin repressor ZEB1. Silencing ZEB1 in TEM4-18 cells resulted in increased E-cadherin and reduced transendothelial migration. TEM4-18 cells also express N-cadherin, which was found to be necessary, but not sufficient for increased transendothelial migration. Our results extend the role of EMT in metastasis to transendothelial migration and implicate ZEB1 and N-cadherin in this process in prostate cancer cells.
Project description:Metastatic colonization involves cancer cell lodgment or adherence in the microvasculature and subsequent migration of those cells across the endothelium into a secondary organ site. To study this process further, we analyzed transendothelial migration of human PC-3 prostate cancer cells in vitro. We isolated a subpopulation of cells, TEM4-18, that crossed an endothelial barrier more efficiently, but surprisingly, were less invasive than parental PC-3 cells in other contexts in vitro. Importantly, TEM4-18 cells were more aggressive than PC-3 cells in a murine metastatic colonization model. Microarray and FACS analysis of these cells showed that the expression of many genes previously associated with leukocyte trafficking and cancer cell extravasation were either unchanged or down-regulated. TEM4-18 cells exhibited characteristic molecular markers of an epithelial-to-mesenchymal transition (EMT), including frank loss of E-cadherin expression and upregulation of the E-cadherin repressor ZEB1. Silencing ZEB1 in TEM4-18 cells resulted in increased E-cadherin and reduced transendothelial migration. TEM4-18 cells also express N-cadherin, which was found to be necessary, but not sufficient for increased transendothelial migration. Our results extend the role of EMT in metastasis to transendothelial migration and implicate ZEB1 and N-cadherin in this process in prostate cancer cells. Experiment Overall Design: We wanted to compare the expression profiles of cells that had undergone transendothelial migration. The parental, and reference cell line, PC-3 was plated onto a confluent human microvascular endothelial cell line from the lung and allowed to migrate across this monolayer. A new cell line, TEM4-18, was isolated from this experiment. We also performed this experiment a second time to isolate a biological replicate of the TEM4-18 cell line, termed TEM2-5. All 3 cell lines, PC-3, TEM4-18, and TEM2-5 are analyzed as replicates in this experiment for a total of 6 samples in this microarray. Both TEM4-18 and TEM2-5 were then compared to PC-3 cells for changes in gene expression.
Project description:In autoimmune diseases, accumulation of activated leukocytes correlates with inflammation and disease progression, and therefore, disruption of leukocyte trafficking is an active area of research. The protein kinase Tpl2 (MAP3K8) regulates leukocyte inflammatory responses and is also being investigated for therapeutic inhibition during autoimmunity. Herein, we addressed the contribution of Tpl2 to the regulation of macrophage chemokine and chemokine receptor expression and subsequent migration in vivo using a mouse model of Tpl2 ablation. We found that gene expression of the chemokine ligands CCL2, CCL7, CXCL2, and CXCL3 as well as the chemokine receptors CCR1 and CCR5 were reduced in macrophages from the bone marrow and peritoneal cavities of tpl2-/- mice following stimulation with LPS. LPS stimulation repressed chemokine receptor expression of CCR1, CCR2 and CCR5. Notably, LPS-induced repression of CCR1 and CCR5 was significantly enhanced in Tpl2-deficient macrophages and was observed to be dependent upon Erk activation and independent of PI3K and mTOR signaling. Consistent with alterations in chemokine and chemokine receptor expression, tpl2-/- macrophages were defective in trafficking to the peritoneal cavity following thioglycollate-induced inflammation. Overall, this study demonstrates a Tpl2-dependent mechanism for macrophage expression of both chemokine receptors and their ligands and provides further insight into how Tpl2 inhibition may disrupt inflammatory networks in vivo. microarray was used to profile the genome-wide expression patterns in Tpl2 wild-type and deficient macrophage.
Project description:Metastatic colonization involves cancer cell lodgment or adherence in the microvasculature and subsequent migration of those cells across the endothelium into a secondary organ site. To study this process further, we analyzed both in vitro and in vivo migration of human PC-3 prostate cancer cells . We isolated 6 subpopulation of cells: TEM4-18 were isolated from in vitro transendothelial migration of PC-3 cells; GS672.Ug, GS683.LALN and JD1203.Lu are single passaged in vivo cell lines from TEM4-18; GS689.Li and GS694.LAd are twice passaged in vivo cell lines from PC-3 cells. All the subpopulations crossed an endothelial barrier more efficiently and more aggressive in a murine metastatic colonization model than parental PC-3 cells. Microarray and FACS analysis of these cells showed that the expression of many genes previously associated with leukocyte trafficking and cancer cell extravasation were either unchanged or down-regulated. These cells exhibited characteristic molecular markers of an epithelial-to-mesenchymal transition, including frank loss of E-cadherin expression and upregulation of the E-cadherin repressor ZEB1. We used microarray to detail the global programme of gene expression underlying cancer metastasis. We wanted to compare the expression profiles of cells that had undergone transendothelial migration in vitro or metastasis in vivo. TEM4-18 was generated from the parental PC-3 that was plated onto a confluent human microvascular endothelial cell line from the lung and allowed to migrate across this monolayer. GS672.Ug were isolated from urogenital after intravenous injection of PC-3 cells. GS683.LALN and JD1203.Lu were isolated from lung after intravenous injection of TEM-418 cells. JD549.Ki were isolated from kidney after intravenous injection PC-3 cells. GS689.Li and GS694.LAd were isolated from liver and left adrenal after intravenous injection of JD549.Ki. All the cell lines are analyzed once except duplicate for TEM4-18 in this experiment for a total of 7 samples in this microarray. All other five sublines were then compared to TEM4-18 cells for changes in gene expression.
Project description:In autoimmune diseases, accumulation of activated leukocytes correlates with inflammation and disease progression, and therefore, disruption of leukocyte trafficking is an active area of research. The protein kinase Tpl2 (MAP3K8) regulates leukocyte inflammatory responses and is also being investigated for therapeutic inhibition during autoimmunity. Herein, we addressed the contribution of Tpl2 to the regulation of macrophage chemokine and chemokine receptor expression and subsequent migration in vivo using a mouse model of Tpl2 ablation. We found that gene expression of the chemokine ligands CCL2, CCL7, CXCL2, and CXCL3 as well as the chemokine receptors CCR1 and CCR5 were reduced in macrophages from the bone marrow and peritoneal cavities of tpl2-/- mice following stimulation with LPS. LPS stimulation repressed chemokine receptor expression of CCR1, CCR2 and CCR5. Notably, LPS-induced repression of CCR1 and CCR5 was significantly enhanced in Tpl2-deficient macrophages and was observed to be dependent upon Erk activation and independent of PI3K and mTOR signaling. Consistent with alterations in chemokine and chemokine receptor expression, tpl2-/- macrophages were defective in trafficking to the peritoneal cavity following thioglycollate-induced inflammation. Overall, this study demonstrates a Tpl2-dependent mechanism for macrophage expression of both chemokine receptors and their ligands and provides further insight into how Tpl2 inhibition may disrupt inflammatory networks in vivo.
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:Metastatic colonization involves cancer cell lodgment or adherence in the microvasculature and subsequent migration of those cells across the endothelium into a secondary organ site. To study this process further, we analyzed both in vitro and in vivo migration of human PC-3 prostate cancer cells . We isolated 6 subpopulation of cells: TEM4-18 were isolated from in vitro transendothelial migration of PC-3 cells; GS672.Ug, GS683.LALN and JD1203.Lu are single passaged in vivo cell lines from TEM4-18; GS689.Li and GS694.LAd are twice passaged in vivo cell lines from PC-3 cells. All the subpopulations crossed an endothelial barrier more efficiently and more aggressive in a murine metastatic colonization model than parental PC-3 cells. Microarray and FACS analysis of these cells showed that the expression of many genes previously associated with leukocyte trafficking and cancer cell extravasation were either unchanged or down-regulated. These cells exhibited characteristic molecular markers of an epithelial-to-mesenchymal transition, including frank loss of E-cadherin expression and upregulation of the E-cadherin repressor ZEB1. We used microarray to detail the global programme of gene expression underlying cancer metastasis.
Project description:Antigen presenting dendritic cells (DCs) and monocytes capture and transport antigens from barrier tissues for presentation to antigen-specific T cells in the draining-lymph nodes (LNs). While DCs enter LNs through afferent lymphatics in a CCR7-dependent manner, how exactly antigen-carrying monocytes reach LNs is less clear since monocytes do not express CCR7 and can also enter LNs via the bloodstream. In steady state, and following injection of several PAMPs, scRNA-seq data on LN mononuclear phagocytes identified LN resident versus migratory type 1 and type 2 conventional (c)DCs despite downregulation of DC subset-defining transcripts, such as Xcr1, Clec9a, H2-Ab1, Sirpa, and Clec10a on migratory cDCs. Migratory cDCs gained expression of transcripts controlling cellular migration such as Ccr7, Ccl17, Ccl22, and Ccl5, while migratory monocytes expressed Ccr5 without Ccr7. Using two tracking methods and a gating strategy that clearly distinguishes migratory CD88hiCD26lo monocytes from CD88-CD26hi cDCs, we found that both captured antigens in the lung and migrated to lung-draining LNs. Using global and mixed-chimeric Ccl5-, Ccr2-, Ccr5-, Ccr7-, and Batf3-deficient mice, we found that CCR5+ monocytes follow CCL5-secreting migratory cDCs to reach the draining LN via lymphatic vessels. In a model of asthma, such recruited monocytes regulated the induction of type 2 immunity. Overall, our data suggest that CCL5-secreting migratory cDCs lay down the chemokine trail for CCR5+ antigen-presenting monocytes to reach draining lymph nodes and regulate adaptive immunity.