Article Commentary: Fas and Cancer

2010 ◽  
Vol 3 ◽  
pp. CMENT.S3147
Author(s):  
Kamal-Eldin Ahmed Abou-Elhamd

Apoptosis is an active process of programmed cell death. Fas is a cell-surface protein which is expressed on activated lymphocytes and known as CD95, TNFRSF6 or APO-1. Fas-L is ligand of Fas and known as CD95 LG or TNFSF6. Apoptosis or cell death is a result of binding of Fas-L to Fas which is expressed on the surfaces of these cells. Cancer cells escape this binding by overexpression of Fas-L or down expression of Fas. Fas and Fas-L exist in membrane bound and soluble forms. The serum level of sFas and sFas-L can be evaluated by immunostaining, immunohistochemical methods, immunofluorescence, flow cytometry and Western blotting. Head and neck squamous cell carcinoma diagnosis, staging and prognosis can be evaluated early and accurately by sFas and sFas-L expression levels detection.

2018 ◽  
Author(s):  
Jack W.D. Blackburn ◽  
Darius H.C. Lau ◽  
Jessica Ellins ◽  
Angela Kipp ◽  
Emily N. Pawlak ◽  
...  

AbstractEfferocytosis – the phagocytic removal of apoptotic cells – is essential for the maintenance of homeostasis and prevention of the inflammatory and autoimmune diseases which can follow the lysis of uncleared apoptotic cells. CD93 is a transmembrane glycoprotein previously implicated in efferocytosis and angiogenesis, and upon mutation, results in the onset of efferocytosis-associated diseases such as atherosclerosis and rheumatoid arthritis. CD93 is produced as a cell surface protein which is shed as soluble CD93, but it is unknown how CD93 mediates efferocytosis or whether its efferocytic activity is mediated by the soluble or membrane-bound form. Herein, we demonstrate that the membrane bound form of CD93 has no phagocytic, efferocytic, or tethering activity, whereas soluble CD93 potently opsonizes apoptotic cells but not a broad range of Gram-Negative, Gram-Positive or fungal microorganisms. Using mass spectrometry, we identified the αxβ2 integrin as the receptor required for soluble CD93-mediated efferocytosis, and via deletion mutagenesis determined that soluble CD93 binds to apoptotic cells via its C-Type Lectin-Like domain, and to αxβ2 by its EGF-like repeats. This bridging of apoptotic cells to the αxβ2 integrin markedly enhanced efferocytosis by macrophages, and could be abrogated by knockdown of αxβ2 integrin. Combined, these data elucidate the mechanism by which CD93 regulates efferocytosis and identify a previously unreported opsonin-receptor system utilized by the immune system for the efferocytic clearance of apoptotic cells.


2018 ◽  
Vol 9 (14) ◽  
pp. 1857-1868 ◽  
Author(s):  
D. Duret ◽  
Z. Haftek-Terreau ◽  
M. Carretier ◽  
T. Berki ◽  
C. Ladavière ◽  
...  

Fluorescent RAFT polymer probes with an activated ester reactive end-group can be advantageously used to label native proteins.


Development ◽  
1987 ◽  
Vol 101 (2) ◽  
pp. 255-265 ◽  
Author(s):  
J.A. Anstrom ◽  
J.E. Chin ◽  
D.S. Leaf ◽  
A.L. Parks ◽  
R.A. Raff

In this report, we use a monoclonal antibody (B2C2) and antibodies against a fusion protein (Leaf et al. 1987) to characterize msp130, a cell surface protein specific to the primary mesenchyme cells of the sea urchin embryo. This protein first appears on the surface of these cells upon ingression into the blastocoel. Immunoelectronmicroscopy shows that msp130 is present in the trans side of the Golgi apparatus and on the extracellular surface of primary mesenchyme cells. Four precursor proteins to msp130 are identified and we show that B2C2 recognizes only the mature form of msp130. We demonstrate that msp130 contains N-linked carbohydrate groups and that the B2C2 epitope is sensitive to endoglycosidase F digestion. Evidence that msp130 is apparently a sulphated glycoprotein is presented. The recognition of the B2C2 epitope of msp130 is disrupted when embryos are cultured in sulphate-free sea water. In addition, two-dimensional immunoblots show that msp130 is an acidic protein that becomes substantially less acidic in the absence of sulphate. We also show that two other independently derived monoclonal antibodies, IG8 (McClay et al. 1983; McClay, Matranga & Wessel, 1985) and 1223 (Carson et al. 1985), recognize msp130, and suggest this protein to be a major cell surface antigen of primary mesenchyme cells.


2019 ◽  
Vol 445 (1) ◽  
pp. 16-28 ◽  
Author(s):  
Yanina-Yasmin Pesch ◽  
Ricarda Hesse ◽  
Tariq Ali ◽  
Matthias Behr

1997 ◽  
Vol 15 (11) ◽  
pp. 3355-3362 ◽  
Author(s):  
A Younes ◽  
U Consoli ◽  
V Snell ◽  
K Clodi ◽  
K O Kliche ◽  
...  

PURPOSE CD30 ligand (CD30L), which is expressed on resting B and activated T lymphocytes, can induce cell death in several CD30+ cell lines. Patients with CD30+ tumors (Hodgkin's disease and Ki-1+ non-Hodgkin's lymphoma) frequently have elevated soluble CD30 (sCD30) levels in their serum, which correlates with a poor prognosis. The role of sCD30 in protecting tumor cells from CD30L-mediated cell death and the pattern of CD30L expression on human peripheral-blood lymphocytes (PBLs) of normal donors and patients with CD30+ tumors are investigated. MATERIALS AND METHODS CD30L surface protein expression was determined by two-color flow cytometry on PBLs of patients with CD30+ tumors and normal individuals. CD30L levels were determined on subsets of PBLs before and after stimulation with phytohemagglutinin (PHA), anti-CD3 antibody, or CD40L. sCD30 was measured by enzyme-linked immunosorbent assay (ELISA). The apoptotic activity of membrane-bound CD30L was tested in a CD30+ cell line by the annexin V-binding method. RESULTS Unstimulated T lymphocytes of normal donors and patients with lymphoma rarely expressed CD30L surface protein, but were able to express it after stimulation with PHA or anti-CD3 antibody. Resting B cells of patients with CD30+ tumors had lower levels of detectable surface CD30L compared with normal donors (mean, 55% and 80.6%, respectively; P = .0008). Patients with high levels of serum sCD30 had lower detectable levels of CD30L on their PBLs (R2 = .72, P = .0008) and exogenous sCD30 blocked membrane-bound CD30L-mediated apoptosis in a CD30+ cell line. CONCLUSION In patients with CD30+ tumors, sCD30 can decrease the availability of CD30L on PBLs. Blocking the apoptosis-inducing activity of CD30L by its soluble receptor may explain how CD30+ tumors escape immunosurveillance and may be related to the reported poor prognosis of patients who have elevated sCD30 levels.


2018 ◽  
Vol 115 (46) ◽  
pp. E10988-E10997 ◽  
Author(s):  
Damaris Bausch-Fluck ◽  
Ulrich Goldmann ◽  
Sebastian Müller ◽  
Marc van Oostrum ◽  
Maik Müller ◽  
...  

Cell-surface proteins are of great biomedical importance, as demonstrated by the fact that 66% of approved human drugs listed in the DrugBank database target a cell-surface protein. Despite this biomedical relevance, there has been no comprehensive assessment of the human surfaceome, and only a fraction of the predicted 5,000 human transmembrane proteins have been shown to be located at the plasma membrane. To enable analysis of the human surfaceome, we developed the surfaceome predictor SURFY, based on machine learning. As a training set, we used experimentally verified high-confidence cell-surface proteins from the Cell Surface Protein Atlas (CSPA) and trained a random forest classifier on 131 features per protein and, specifically, per topological domain. SURFY was used to predict a human surfaceome of 2,886 proteins with an accuracy of 93.5%, which shows excellent overlap with known cell-surface protein classes (i.e., receptors). In deposited mRNA data, we found that between 543 and 1,100 surfaceome genes were expressed in cancer cell lines and maximally 1,700 surfaceome genes were expressed in embryonic stem cells and derivative lines. Thus, the surfaceome diversity depends on cell type and appears to be more dynamic than the nonsurface proteome. To make the predicted surfaceome readily accessible to the research community, we provide visualization tools for intuitive interrogation (wlab.ethz.ch/surfaceome). The in silico surfaceome enables the filtering of data generated by multiomics screens and supports the elucidation of the surfaceome nanoscale organization.


Sign in / Sign up

Export Citation Format

Share Document