Staphylococcal SSL5 inhibits leukocyte activation by chemokines and anaphylatoxins

Blood ◽  
2009 ◽  
Vol 113 (2) ◽  
pp. 328-337 ◽  
Author(s):  
Jovanka Bestebroer ◽  
Kok P. M. van Kessel ◽  
Hafida Azouagh ◽  
Annemiek M. Walenkamp ◽  
Ingrid G. J. Boer ◽  
...  
Keyword(s):  
Chemokine Receptors ◽  
Actin Polymerization ◽  
Sialyl Lewis X ◽  
Leukocyte Activation ◽  
Sialyl Lewis ◽  
Anaphylatoxin Receptors ◽  
Protein Nature ◽  
G Protein Coupled ◽  
Antibody Competition ◽  
Antiinflammatory Compound

Abstract Staphylococcus aureus secretes several virulence factors modulating immune responses. Staphylococcal superantigen-like (SSL) proteins are a family of 14 exotoxins with homology to superantigens, but with generally unknown function. Recently, we showed that SSL5 binds to P-selectin glycoprotein ligand 1 dependently of sialyl Lewis X and inhibits P-selectin–dependent neutrophil rolling. Here, we show that SSL5 potently and specifically inhibits leukocyte activation by anaphylatoxins and all classes of chemokines. SSL5 inhibited calcium mobilization, actin polymerization, and chemotaxis induced by chemokines and anaphylatoxins but not by other chemoattractants. Antibody competition experiments showed that SSL5 targets several chemokine and anaphylatoxin receptors. In addition, transfection studies showed that SSL5 binds glycosylated N-termini of all G protein–coupled receptors (GPCRs) but only inhibits stimuli of protein nature that require the receptor N-terminus for activation. Furthermore, SSL5 increased binding of chemokines to cells independent of chemokine receptors through their common glycosaminoglycan-binding site. Importance of glycans was shown for both GPCR and chemokine binding. Thus, SSL5 is an important immunomodulatory protein of S aureus that targets several crucial, initial stages of leukocyte extravasation. It is therefore a potential new antiinflammatory compound for diseases associated with chemoattractants and their receptors and disorders characterized by excessive recruitment of leukocytes.

Persistent HIV Transcription Induces Sialyl-Lewis-X Glyco-Antigen Cell-Surface Expression

2020 ◽  
Author(s):  
Florent Colomb ◽  
Leila B. Giron ◽  
Leticia Kuri Cervantes ◽  
Tongcui Ma ◽  
Samson Adeniji ◽  
...  
Keyword(s):  
Cell Surface ◽  
Surface Expression ◽  
Sialyl Lewis X ◽  
Cell Surface Expression ◽  
Lewis X ◽  
Hiv Transcription ◽  
Sialyl Lewis

scholarly journals Sialyl Lewis X mimics derived from a pharmacophore search are selectin inhibitors with anti-inflammatory activity.

1994 ◽  
Vol 269 (31) ◽  
pp. 19663-19666
Author(s):  
B.N. Rao ◽  
M.B. Anderson ◽  
J.H. Musser ◽  
J.H. Gilbert ◽  
M.E. Schaefer ◽  
...  
Keyword(s):  
Inflammatory Activity ◽  
Sialyl Lewis X ◽  
Lewis X ◽  
Sialyl Lewis ◽  
Anti Inflammatory

scholarly journals Mycobacterium tuberculosis Infection Up-Regulates Sialyl Lewis X Expression in the Lung Epithelium

2021 ◽  
Vol 9 (1) ◽  
pp. 99
Author(s):  
Rita Matos ◽  
Kaori L. Fonseca ◽  
Stefan Mereiter ◽  
Ana Raquel Maceiras ◽  
Joana Gomes ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Biosynthetic Pathway ◽  
Molecular Mechanisms ◽  
Tuberculosis Infection ◽  
Host Susceptibility ◽  
Sialyl Lewis X ◽  
Lung Pathology ◽  
Lung Epithelium ◽  
Lewis X ◽  
Sialyl Lewis

Glycans display increasingly recognized roles in pathological contexts, however, their impact in the host-pathogen interplay in many infectious diseases remains largely unknown. This is the case for tuberculosis (TB), one of the ten most fatal diseases worldwide, caused by infection of the bacteria Mycobacterium tuberculosis. We have recently reported that perturbing the core-2 O-glycans biosynthetic pathway increases the host susceptibility to M. tuberculosis infection, by disrupting the neutrophil homeostasis and enhancing lung pathology. In the present study, we show an increased expression of the sialylated glycan structure Sialyl-Lewis X (SLeX) in the lung epithelium upon M. tuberculosis infection. This increase in SLeX glycan epitope is accompanied by an altered lung tissue transcriptomic signature, with up-regulation of genes codifying enzymes that are involved in the SLeX core-2 O-glycans biosynthetic pathway. This study provides novel insights into previously unappreciated molecular mechanisms involving glycosylation, which modulate the host response to M. tuberculosis infection, possibly contributing to shape TB disease outcome.

scholarly journals Ras-mediated activation of the TORC2–PKB pathway is critical for chemotaxis

2010 ◽  
Vol 190 (2) ◽  
pp. 233-245 ◽  
Author(s):  
Huaqing Cai ◽  
Satarupa Das ◽  
Yoichiro Kamimura ◽  
Yu Long ◽  
Carole A. Parent ◽  
...  
Keyword(s):  
Cell Migration ◽  
Actin Polymerization ◽  
Time Course ◽  
Specific Inhibitor ◽  
Ras Proteins ◽  
Extracellular Signaling ◽  
Upstream Regulator ◽  
Pkb Phosphorylation ◽  
G Protein Coupled

In chemotactic cells, G protein–coupled receptors activate Ras proteins, but it is unclear how Ras-associated pathways link extracellular signaling to cell migration. We show that, in Dictyostelium discoideum, activated forms of RasC prolong the time course of TORC2 (target of rapamycin [Tor] complex 2)-mediated activation of a myristoylated protein kinase B (PKB; PKBR1) and the phosphorylation of PKB substrates, independently of phosphatidylinositol-(3,4,5)-trisphosphate. Paralleling these changes, the kinetics of chemoattractant-induced adenylyl cyclase activation and actin polymerization are extended, pseudopodial activity is increased and mislocalized, and chemotaxis is impaired. The effects of activated RasC are suppressed by deletion of the TORC2 subunit PiaA. In vitro RasCQ62L-dependent PKB phosphorylation can be rapidly initiated by the addition of a PiaA-associated immunocomplex to membranes of TORC2-deficient cells and blocked by TOR-specific inhibitor PP242. Furthermore, TORC2 binds specifically to the activated form of RasC. These results demonstrate that RasC is an upstream regulator of TORC2 and that the TORC2–PKB signaling mediates effects of activated Ras proteins on the cytoskeleton and cell migration.

Sulfated Sialyl Lewis X, the Putative L-Selectin Ligand, Detected on Endothelial Cells of High Endothelial Venules by a Distinct Set of Anti-Sialyl Lewis X Antibodies

1997 ◽  
Vol 230 (3) ◽  
pp. 546-551 ◽  
Author(s):  
Chikako Mitsuoka ◽  
Naoko Kawakami-Kimura ◽  
Mikiko Kasugai-Sawada ◽  
Nozomu Hiraiwa ◽  
Ken'ichi Toda ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Sialyl Lewis X ◽  
Lewis X ◽  
High Endothelial Venules ◽  
Sialyl Lewis ◽  
Selectin Ligand

scholarly journals Thieno[2,3-b]Pyridine Derivative Targets Epithelial, Mesenchymal and Hybrid CD15s+ Breast Cancer Cells

Medicines ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 32
Author(s):  
Sandra Marijan ◽  
Angela Mastelić ◽  
Anita Markotić ◽  
Nikolina Režić-Mužinić ◽  
Nikolina Vučenović ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Triple Negative ◽  
Sialyl Lewis X ◽  
Hematogenous Metastasis ◽  
Pyridine Derivative ◽  
Sialyl Lewis ◽  
Cell Subpopulations ◽  
Critical Process

The adhesion of cancer cells to vascular endothelium is a critical process in hematogenous metastasis and might be similar to the recruitment of leukocytes at the site of inflammation. It is mediated by E-selectin and its ligands, of which the most stereospecific is a glycoconjugate sialyl Lewis x (CD15s), which may be expressed as an oligosaccharide branch of the CD44 glycoprotein, as well as a self-contained glycosphingolipid. It is also known that increased sialylation of glycoconjugates is a feature of malignant cells. The aim of the study was to analyse the effect of a novel thieno[2,3-b]pyridine, compound 1, in MDA-MB-231 triple-negative breast cancer cells (TNBCs) upon CD15s and CD44 expression in different cell subpopulations using flow cytometry. CD15s expression was compared between mesenchymal-like cancer stem cells (CSC, CD44+CD24−), epithelial cells without CD44 (CD44−CD24+ and CD44−CD24−), and CD44+CD24+ cells that exhibit mesenchymal and epithelial features. In addition, expression of CD44 in CD15s+CSC and CD15s−CSC was determined. Compound 1 significantly decreased the percentage of CD15s+CSC, CD15s+CD44+CD24+, and CD15s+CD44− subpopulations, as well as the expression of CD15s in CD44+CD24+ and CD44− cells, and therefore shows potential as a treatment for TNBC.

Sign in / Sign up

Export Citation Format

Share Document