Search results for "CD59"
showing 10 items of 12 documents
Glucose-induced loss of glycosyl-phosphatidylinositol-anchored membrane regulators of complement activation (CD59, CD55) by in vitro cultured human u…
2000
Aims/hypothesis. This study examines whether increased glucose concentrations are responsible for a decreased expression of membrane regulators of complement activation molecules. The effect of high glucose in determining an increase in membrane attack complex deposition on endothelial cells was also investigated. Methods. Endothelial cells were isolated from umbilical cord tissue, cultured in the presence of increased concentrations of glucose, and the expression of CD46, CD55, and CD59 was detected by ELISA (enzyme-linked immunosorbent assay) and by flow cytometry. Glucose-treated endothelial cells were also incubated with antiendothelial cell antibodies and fresh complement to assess the…
CD59 (homologous restriction factor 20), a plasma membrane protein that protects against complement C5b-9 attack, in human atherosclerotic lesions
1992
Blood cells express a cell membrane protein, termed homologous restriction factor 20 (HRF20) and identical to CD59, that can inhibit complement C5b-9 insertion into their membranes. In this report, we investigated by immunohistochemistry whether CD59 was present on cells in human atherosclerotic lesions since membranous C5b-9(m) has been found in lesions. Using a monoclonal anti-CD59 antibody, a cellular CD59 staining pattern was apparent in nearly all lesion specimens. CD59 stain co-localised with macrophage (CD14), T lymphocyte (CD7), endothelial cell (anti-factor VIII related antigen) and smooth muscle cell cytoskeletal-specific antigens (anti-alpha actin and muscle myosin). Endothelial …
Expression and regulation by interferon-γ of the membrane-bound complement regulators CD46 (MCP), CD55 (DAF) and CD59 in gastrointestinal tumours
1999
The membrane-bound complement inhibitors CD46 (membrane cofactor protein), CD55 (decay-accelerating factor) and CD59 (protectin) protect tumour cells against lysis by activated complement. In this study, a total of 14 (3 gastric, 3 colonic and 8 pancreatic) gastrointestinal tumour cell lines were examined for the expression of CD46, CD55 and CD59 with respect to the regulatory efficacy of interferon-gamma (IFN-gamma). The effects of IFN-gamma on mRNA and protein expression levels of CD46, CD55 and CD59 were evaluated by Northern blot hybridisation, RT-PCR, flow cytometry and immunostaining. In unstimulated cell lines, CD46 and CD59 transcripts were expressed at comparable levels, whereas th…
In vivo targeting of human neutralizing antibodies against CD55 and CD59 to lymphoma cells increases the antitumor activity of rituximab.
2007
AbstractAn in vivo model of human CD20+ B-lymphoma was established in severe combined immunodeficiency mice to test the ability of human neutralizing miniantibodies to CD55 and CD59 (MB55 and MB59) to enhance the therapeutic effect of rituximab. The miniantibodies contained single-chain fragment variables and the hinge-CH2-CH3 domains of human IgG1. LCL2 cells were selected for the in vivo study among six B-lymphoma cell lines for their high susceptibility to rituximab-dependent complement-mediated killing enhanced by MB55 and MB59. The cells injected i.p. primarily colonized the liver and spleen, leading to the death of the animals within 30 to 40 days. Thirty percent of mice receiving bio…
Influence of different complement sources in apoptosis of B-CLL cells with rituximab
2004
Abstract Introduction: Rituximab (Rtx) is an anti-CD20 monoclonal antibody that is clinically active in B-cell chronic lymphocytic leukemia (B-CLL). In vitro and in vivo data indicate that Rtx mediates its biologic effect through multiple mechanisms including apoptosis, complement dependent cytotoxicity (CDC), and antibody dependent cellular cytotoxicity (ADCC). Objetive: To study in vitro sensitivity to apoptosis by Rtx of isolated cells obtained from B-CLL patients Binet stage A, in the presence of complement from different sources and correlate with CD20 and CD59 molecules expression. Methods: PBMCs were isolated from peripheral blood samples by centrifugation on a Ficoll/Hypaque gradien…
Bispecific antibodies targeting tumor-associated antigens and neutralizing complement regulators increase the efficacy of antibody-based immunotherap…
2015
The efficacy of antibody-based immunotherapy is due to the activation of apoptosis, the engagement of antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity (CDC). We developed a novel strategy to enhance CDC using bispecific antibodies (bsAbs) that neutralize the C-regulators CD55 and CD59 to enhance C-mediated functions. Two bsAbs (MB20/55 and MB20/59) were designed to recognize CD20 on one side. The other side neutralizes CD55 or CD59. Analysis of CDC revealed that bsAbs could kill 4-25 times more cells than anti-CD20 recombinant antibody in cell lines or cells isolated from patients with chronic lymphocytic leukemia. The pharmacokinetics of the bsAbs was evaluate…
Paroxysmal nocturnal hemoglobinuria-like phenotype and thrombotic risk in several clinical disorders.
2021
Thrombotic risk in paroxysmal nocturnal hemoglobinuria-like (PNH-like) phenotype
2020
The complement system is an essential component of the innate immune defence that, if overly activated, may damage organs and tissues. For this reason, there is a fine complement regulatory system. The complement modulation system includes two proteins with important regulatory activity, CD55 or decay accelerating factor (DAF) and CD59 or membrane inhibitor of reactive lysis (MIRL). The paroxysmal nocturnal hemoglobinuria (PNH) is a clonal and non-neoplastic disease characterized by intravascular haemolysis, occurrence of thrombosis and bone marrow failure. In clinical practice, in opposition to PNH, a variety of pathological conditions have been observed with an acquired and non-genetic de…
Paroxysmal nocturnal haemoglobinuria: When delay in diagnosis and long therapy occurs
2017
Paroxysmal nocturnal hemoglobinuria (PNH) is a rare clonal disorder characterized by hemolytic anemia, bone marrow failure and thrombosis, caused by a somaticmutation in PIG-A gene that results in theabsence of CD55 and CD59, two important complement regulatory proteins. In thispaper, a case of PNH is retrospectively examined looking for clinical and laboratory features, and the entire course of the disease from the onset of the symptoms isdescribed, together with an adequate follow-up over a 7-years treatment period. Inthis case, the not specificity and the limited clinical relevance of the symptoms led to adelay in diagnosis. After thrombosis, Eculizumab therapy has been shown to be effec…