scholarly journals Lipid phosphate phosphatase 3 enables efficient thymic egress

2011 ◽  
Vol 208 (6) ◽  
pp. 1267-1278 ◽  
Author(s):  
Béatrice Bréart ◽  
Willy D. Ramos-Perez ◽  
Alejandra Mendoza ◽  
Abdelghaffar K. Salous ◽  
Michael Gobert ◽  
...  
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
Epithelial Cells ◽  
Inflammatory Responses ◽  
Conditional Deletion ◽  
Sphingosine 1 Phosphate ◽  
Lipid Phosphate ◽  
Lymphocyte Egress ◽  
Lines Of Evidence

The signaling lipid sphingosine-1-phosphate (S1P) stabilizes the vasculature, directs lymphocyte egress from lymphoid organs, and shapes inflammatory responses. However, little is known about how S1P distribution is controlled in vivo, and it is not clear how a ubiquitously made lipid functions as a signal that requires precise spatial and temporal control. We have found that lipid phosphate phosphatase 3 (LPP3) enables efficient export of mature T cells from the thymus into circulation, and several lines of evidence suggest that LPP3 promotes exit by destroying thymic S1P. Although five additional S1P-degrading enzymes are expressed in the thymus, they cannot compensate for the loss of LPP3. Moreover, conditional deletion of LPP3 in either epithelial cells or endothelial cells is sufficient to inhibit egress. These results suggest that S1P generation and destruction are tightly regulated and that LPP3 is essential to establish the balance.

scholarly journals Cell-surface residence of sphingosine 1-phosphate receptor 1 on lymphocytes determines lymphocyte egress kinetics

2010 ◽  
Vol 207 (7) ◽  
pp. 1475-1483 ◽  
Author(s):  
Shobha Thangada ◽  
Kamal M. Khanna ◽  
Victoria A. Blaho ◽  
Myat Lin Oo ◽  
Dong-Soon Im ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Surface ◽  
Agonist Stimulation ◽  
Primary Determinant ◽  
Sphingosine 1 Phosphate ◽  
Lymphocyte Egress ◽  
G Protein Coupled ◽  
Kinetics In Vivo ◽  
Knockin Mouse

The sphingosine 1-phosphate receptor 1 (S1P1) promotes lymphocyte egress from lymphoid organs. Previous work showed that agonist-induced internalization of this G protein–coupled receptor correlates with inhibition of lymphocyte egress and results in lymphopenia. However, it is unclear if S1P1 internalization is necessary for this effect. We characterize a knockin mouse (S1p1rS5A/S5A) in which the C-terminal serine-rich S1P1 motif, which is important for S1P1 internalization but dispensable for S1P1 signaling, is mutated. T cells expressing the mutant S1P1 showed delayed S1P1 internalization and defective desensitization after agonist stimulation. Mutant mice exhibited significantly delayed lymphopenia after S1P1 agonist administration or disruption of the vascular S1P gradient. Adoptive transfer experiments demonstrated that mutant S1P1 expression in lymphocytes, rather than endothelial cells, facilitated this delay in lymphopenia. Thus, cell-surface residency of S1P1 on T cells is a primary determinant of lymphocyte egress kinetics in vivo.

scholarly journals Enhancing the Nrf2 Antioxidant Signaling Provides Protection Against Trichloroethene-mediated Inflammation and Autoimmune Response

2020 ◽  
Vol 175 (1) ◽  
pp. 64-74 ◽  
Author(s):  
Nivedita Banerjee ◽  
Hui Wang ◽  
Gangduo Wang ◽  
M Firoze Khan
Keyword(s):  
Oxidative Stress ◽  
T Cells ◽  
Molecular Mechanisms ◽  
Inflammatory Responses ◽  
Autoimmune Response ◽  
Mediated Effects ◽  
Antioxidant Gene Expression ◽  
Responsive Element

Abstract Trichloroethene (trichloroethylene, TCE) and one of its reactive metabolites dichloroacetyl chloride (DCAC) are associated with the induction of autoimmunity in MRL+/+ mice. Although oxidative stress plays a major role in TCE-/DCAC-mediated autoimmunity, the underlying molecular mechanisms still need to be delineated. Nuclear factor (erythroid-derived 2)-like2 (Nrf2) is an oxidative stress-responsive transcription factor that binds to antioxidant responsive element (ARE) and provides protection by regulating cytoprotective and antioxidant gene expression. However, the potential of Nrf2 in the regulation of TCE-/DCAC-mediated autoimmunity is not known. This study thus focused on establishing the role of Nrf2 and consequent inflammatory responses in TCE-/DCAC-mediated autoimmunity. To achieve this, we pretreated Kupffer cells (KCs) or T cells with/without tert-butylhydroquinone (tBHQ) followed by treatment with DCAC. In both KCs and T cells, DCAC treatment significantly downregulated Nrf2 and HO-1 expression along with induction of Keap-1 and caspase-3, NF-κB (p65), TNF-α, and iNOS, whereas pretreatment of these cells with tBHQ attenuated these responses. The in vitro findings were further verified in vivo by treating female MRL+/+ mice with TCE along with/without sulforaphane. TCE exposure in mice also led to reduction in Nrf2 and HO-1 but increased phospho-NF-κB (p-p65) and iNOS along with increased anti-dsDNA antibodies. Interestingly, sulforaphane treatment led to amelioration of TCE-mediated effects, resulting in Nrf2 activation and reduction in inflammatory and autoimmune responses. Our results show that TCE/DCAC mediates an impairment in Nrf2 regulation. Attenuation of TCE-mediated autoimmunity via activation of Nrf2 supports that antioxidants sulforaphane/tBHQ could be potential therapeutic agents for autoimmune diseases.

scholarly journals Human Effector Memory CD4+ T Cells Directly Recognize Allogeneic Endothelial Cells In Vitro and In Vivo

2007 ◽  
Vol 179 (7) ◽  
pp. 4397-4404 ◽  
Author(s):  
Stephen L. Shiao ◽  
Nancy C. Kirkiles-Smith ◽  
Benjamin R. Shepherd ◽  
Jennifer M. McNiff ◽  
Edward J. Carr ◽  
...  
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
Cd4 T Cells ◽  
Effector Memory ◽  
Memory Cd4 T Cells

scholarly journals Peyer's Patch Dendritic Cells Process Viral Antigen from Apoptotic Epithelial Cells in the Intestine of Reovirus-infected Mice

2004 ◽  
Vol 200 (2) ◽  
pp. 235-245 ◽  
Author(s):  
Marina N. Fleeton ◽  
Nikhat Contractor ◽  
Francisco Leon ◽  
J. Denise Wetzel ◽  
Terence S. Dermody ◽  
...  
Keyword(s):  
T Cells ◽  
Epithelial Cells ◽  
Cd4 T Cells ◽  
Cell Protein ◽  
Peyer’S Patch ◽  
Peyer's Patch ◽  
Antigen Uptake ◽  
Cross Presentation

We explored the role of Peyer's patch (PP) dendritic cell (DC) populations in the induction of immune responses to reovirus strain type 1 Lang (T1L). Immunofluorescence staining revealed the presence of T1L structural (σ1) and nonstructural (σNS) proteins in PPs of T1L-infected mice. Cells in the follicle-associated epithelium contained both σ1 and σNS, indicating productive viral replication. In contrast, σ1, but not σNS, was detected in the subepithelial dome (SED) in association with CD11c+/CD8α−/CD11blo DCs, suggesting antigen uptake by these DCs in the absence of infection. Consistent with this possibility, PP DCs purified from infected mice contained σ1, but not σNS, and PP DCs from uninfected mice could not be productively infected in vitro. Furthermore, σ1 protein in the SED was associated with fragmented DNA by terminal deoxy-UTP nick-end labeling staining, activated caspase-3, and the epithelial cell protein cytokeratin, suggesting that DCs capture T1L antigen from infected apoptotic epithelial cells. Finally, PP DCs from infected mice activated T1L-primed CD4+ T cells in vitro. These studies show that CD8α−/CD11blo DCs in the PP SED process T1L antigen from infected apoptotic epithelial cells for presentation to CD4+ T cells, and therefore demonstrate the cross-presentation of virally infected cells by DCs in vivo during a natural viral infection.

scholarly journals Regulatory T Cells Protect Fine Particulate Matter-Induced Inflammatory Responses in Human Umbilical Vein Endothelial Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Wen-cai Zhang ◽  
Yan-ge Wang ◽  
Zheng-feng Zhu ◽  
Fang-qin Wu ◽  
Yu-dong Peng ◽  
...  
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
Particulate Matter ◽  
Inflammatory Cytokines ◽  
Fine Particles ◽  
Inflammatory Responses ◽  
Umbilical Vein ◽  
Fine Particulate Matter ◽  
Fine Particulate ◽  
Umbilical Vein Endothelial Cells

Objective. To investigate the role of CD4+CD25+T cells (Tregs) in protecting fine particulate matter (PM-) induced inflammatory responses, and its potential mechanisms.Methods. Human umbilical vein endothelial cells (HUVECs) were treated with graded concentrations (2, 5, 10, 20, and 40 µg/cm2) of suspension of fine particles for 24h. For coculture experiment, HUVECs were incubated alone, with CD4+CD25−T cells (Teff), or with Tregs in the presence of anti-CD3 monoclonal antibodies for 48 hours, and then were stimulated with or without suspension of fine particles for 24 hours. The expression of adhesion molecules and inflammatory cytokines was examined.Results. Adhesion molecules, including vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1), and inflammatory cytokines, such as interleukin (IL-) 6 and IL-8, were increased in a concentration-dependent manner. Moreover, the adhesion of human acute monocytic leukemia cells (THP-1) to endothelial cells was increased and NF-κB activity was upregulated in HUVECs after treatment with fine particles. However, after Tregs treatment, fine particles-induced inflammatory responses and NF-κB activation were significantly alleviated. Transwell experiments showed that Treg-mediated suppression of HUVECs inflammatory responses impaired by fine particles required cell contact and soluble factors.Conclusions. Tregs could attenuate fine particles-induced inflammatory responses and NF-κB activation in HUVECs.

The Rac activator Tiam1 controls efficient T-cell trafficking and route of transendothelial migration

Blood ◽  
2009 ◽  
Vol 113 (24) ◽  
pp. 6138-6147 ◽  
Author(s):  
Audrey Gérard ◽  
Rob A. van der Kammen ◽  
Hans Janssen ◽  
Saskia I. Ellenbroek ◽  
John G. Collard
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
T Cell ◽  
Transendothelial Migration ◽  
Contact Hypersensitivity ◽  
Cell Trafficking ◽  
T Cell Trafficking ◽  
Cell Arrest

Abstract Migration toward chemoattractants is a hallmark of T-cell trafficking and is essential to produce an efficient immune response. Here, we have analyzed the function of the Rac activator Tiam1 in the control of T-cell trafficking and transendothelial migration. We found that Tiam1 is required for chemokine- and S1P-induced Rac activation and subsequent cell migration. As a result, Tiam1-deficient T cells show reduced chemotaxis in vitro, and impaired homing, egress, and contact hypersensitivity in vivo. Analysis of the T-cell transendothelial migration cascade revealed that PKCζ/Tiam1/Rac signaling is dispensable for T-cell arrest but is essential for the stabilization of polarization and efficient crawling of T cells on endothelial cells. T cells that lack Tiam1 predominantly transmigrate through individual endothelial cells (transcellular migration) rather than at endothelial junctions (paracellular migration), suggesting that T cells are able to change their route of transendothelial migration according to their polarization status and crawling capacity.

scholarly journals A Tissue-Engineered Tracheobronchial In Vitro Co-Culture Model for Determining Epithelial Toxicological and Inflammatory Responses

Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 631
Author(s):  
Luis Soriano ◽  
Tehreem Khalid ◽  
Fergal J. O'Brien ◽  
Cian O'Leary ◽  
Sally-Ann Cryan
Keyword(s):  
Epithelial Cells ◽  
Inflammatory Responses ◽  
Bronchial Epithelial Cells ◽  
Lung Fibroblasts ◽  
Drug Induced ◽  
Bronchial Epithelial ◽  
Culture Model ◽  
Epithelial Cultures

Translation of novel inhalable therapies for respiratory diseases is hampered due to the lack of in vitro cell models that reflect the complexity of native tissue, resulting in many novel drugs and formulations failing to progress beyond preclinical assessments. The development of physiologically-representative tracheobronchial tissue analogues has the potential to improve the translation of new treatments by more accurately reflecting in vivo respiratory pharmacological and toxicological responses. Herein, advanced tissue-engineered collagen hyaluronic acid bilayered scaffolds (CHyA-B) previously developed within our group were used to evaluate bacterial and drug-induced toxicity and inflammation for the first time. Calu-3 bronchial epithelial cells and Wi38 lung fibroblasts were grown on either CHyA-B scaffolds (3D) or Transwell® inserts (2D) under air liquid interface (ALI) conditions. Toxicological and inflammatory responses from epithelial monocultures and co-cultures grown in 2D or 3D were compared, using lipopolysaccharide (LPS) and bleomycin challenges to induce bacterial and drug responses in vitro. The 3D in vitro model exhibited significant epithelial barrier formation that was maintained upon introduction of co-culture conditions. Barrier integrity showed differential recovery in CHyA-B and Transwell® epithelial cultures. Basolateral secretion of pro-inflammatory cytokines to bacterial challenge was found to be higher from cells grown in 3D compared to 2D. In addition, higher cytotoxicity and increased basolateral levels of cytokines were detected when epithelial cultures grown in 3D were challenged with bleomycin. CHyA-B scaffolds support the growth and differentiation of bronchial epithelial cells in a 3D co-culture model with different transepithelial resistance in comparison to the same co-cultures grown on Transwell® inserts. Epithelial cultures in an extracellular matrix like environment show distinct responses in cytokine release and metabolic activity compared to 2D polarised models, which better mimic in vivo response to toxic and inflammatory stimuli offering an innovative in vitro platform for respiratory drug development.

Abstract 116: Slit-Robo Signaling Regulates Lipopolysaccharide-induced Endothelial Inflammation and Expression of Slit/Robo is Dysregulated During Endotoxemia

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Helong Zhao ◽  
Appakkudal Anand ◽  
Ramesh Ganju
Keyword(s):  
Endothelial Cells ◽  
Cell Adhesion ◽  
Inflammatory Responses ◽  
Umbilical Vein ◽  
Model Studies ◽  
Endothelial Inflammation ◽  
Anti Inflammatory ◽  
Whole Heart

Abstract Introduction: Lipopolysaccharide (LPS) is one of the critical factors which induce endothelial inflammation during the pathogenesis of atherosclerosis, endocarditis and sepsis shock induced heart injury. The secretory Slit2 protein and its endothelial receptors Robo1 and Robo4 have been shown to regulate mobility and permeability of endothelial cells, which could be functional in regulating LPS induced endothelial inflammation. Hypothesis: We hypothesized that in addition to regulating permeability and migration of endothelial cells, Slit2-Robo1/4 signaling might regulate other LPS-induced endothelial inflammatory responses. Methods and Results: Using Human Umbilical Vein Endothelial Cells (HUVEC) culture, we observed that Slit2 treatment suppressed LPS-induced secretion of pro-inflammatory cytokines (including GM-CSF), cell adhesion molecule upregulation and monocyte (THP-1 cell) adhesion. With siRNA knock down techniques, we further confirmed that this anti-inflammatory effect is mediated by the interaction of Slit2 with its dominant receptor in endothelial cells, Robo4, though the much lesser expressed minor receptor Robo1 is pro-inflammatory. Our signaling studies showed that downstream of Robo4, Slit2 suppressed inflammatory gene expression by inhibiting the Pyk2 - NF-kB pathway following LPS-TLR4 interaction. In addition, Slit2 can induce a positive feedback to its expression and downregulate the pro-inflammatory Robo1 receptor via mediation of miR-218. Moreover, both in in vitro studies using HUVEC and in vivo mouse model studies indicated that LPS also causes endothelial inflammation by downregulating the anti-inflammatory Slit2 and Robo4 and upregulating the pro-inflammatory Robo1 during endotoxemia, especially in mouse arterial endothelial cells and whole heart. Conclusions: Slit2-Robo1/4 signaling is important in regulation of LPS induced endothelial inflammation, and LPS in turn causes inflammation by interfering with the expression of Slit2, Robo1 and Robo4. This implies that Slit2-Robo1/4 is a key regulator of endothelial inflammation and its dysregulation during endotoxemia is a novel mechanism for LPS induced cardiovascular pathogenesis.

Abstract 531: Tie-2/Cre--Mediated Conditional Deletion of Lipid Phosphate Phosphatase-3 Reveals Its Role in Endothelial Cell Apoptosis

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Ishita Chatterjee ◽  
Kishore K Wary
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Genome Wide Association Study ◽  
Vascular Endothelial Cell ◽  
Protein Levels ◽  
Conditional Deletion ◽  
Transmission Electron ◽  
Increased Risk

Rationale: A recent genome-wide association study (GWAS) has linked a frequently occurring variation in the LPP3 (also known as PPAP2b) loci to increased risk of coronary heart disease (CAD). However, the in vivo function of LPP3 in vascular endothelial cell is incompletely understood. Goal: To address the endothelial cell (EC) specific function of Lpp3 in mice. Results: Tie-2/Cre mediated Lpp3 deletion did not affect normal vasculogenesis in early embryonic development, in contrast, in late embryonic stages it led to impaired angiogenesis associated with hemorrhage, edema and late embryonic lethal phenotype. Immunohistochemical staining followed by microscopic analyses of mutant embryos revealed reduced fibronectin and VE-cadherin expression throughout different vascular bed, and increased apoptosis in CD31+ vascular structures. Transmission electron microscopy (TEM) showed the presence of apoptotic endothelial cells and disruption of adherens junctions in mutant embryos. LPP3-knockdown in vitro showed an increase in p53 and p21 protein levels, with concomitant decrease in cell proliferation. LPP3-knockdown also decreased transendothelial electrical resistance (TER), interestingly re-expression of ß-catenin cDNA into LPP3-depleted endothelial cells partially restored the effect of loss of LPP3. Conclusion: These results suggest the ability of LPP3 to regulate survival and apoptotic activities of endothelial cells during patho/physiological angiogenesis.

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