Search results for "CD55 Antigens"

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…

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…

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…

Protective role of the complement regulatory protein human CD-55 in cardiac xenograft: a descriptive study and a revision of the literature.

2002

The limited and inadequate availability of organs from human donors has resulted in the utilisation of xenografts as an alternative tool. Nevertheless, hyperacute rejection (HAR) following xenograft determines the loss of the transplanted organ. The “primum movens” is the activation of the complement pathway mediated by the binding of natural xenogenic antibodies to the endothelium of the graft, followed by the lysis of the endothelial cells with subsequent oedema, thrombosis and necrosis of the transplanted organ. In this work we describe morphological and biomolecular observations of isolated human-decay accelerating factor (h-DAF, CD55) transgenic pig hearts, after perfusion for four hou…

hDAF expression in hearts of transgenic pigs obtained by sperm-mediated gene transfer.

2000

TRANSPLANTATON has been the choice option to treat successfully an increasing number of acute and chronic human pathologies with declining morbidity and mortality. However, availability of organs from human donors is limited and dramatically inadequate with respect to patient requests. Xenotransplantation from large-sized mammals has thus been reconsidered as a tool to overcome the present unbalance between organ offers and requests. Pigs have been chosen because they can be easily and cheaply bred; they do not raise ethical questions—their use as alimentary resources is generally admitted; and they possess organs largely human compatible for size, anatomical organization, and physiology. N…

Efficiency of transgenesis using sperm-mediated gene transfer: generation of hDAF transgenic pigs.

2000

SINCE the beginning of this century, replacement of failing human organs with their animal counterparts has been an interesting topic of debate for writers and scientists. In the 1960s, prolonged survival after kidney transplantation from chimpanzee to human was obtained in the United States and Europe. Nevertheless, both the progressive improvement in surgical technique and in immunosuppressant therapy and the availability of cadaveric organs and living donation have reduced the interest in xenotransplantation. Because of the increasing requests for organs and the lack of donors to meet that need, xenotransplantation has become a reliable option again for temporary organ replacement (eg, o…

Virus-receptor interactions of coxsackie B viruses and their putative influence on cardiotropism

2003

Specific virus-receptor interactions are important determinants in the pathogenesis of viral infections, influencing the location and initiation of primary infection as well as the viral spread to other target organs in the postviremic phase. Coxsackieviruses of group B (CVB) specifically interact with at least two receptor proteins, the coxsackievirus-adenovirus receptor (CAR) and the decay-accelerating factor (DAF), and cause a broad spectrum of diseases, including acute and chronic myocarditis. In the human heart, CAR is predominantly expressed in intercalated discs, regions of utmost importance for the functional integrity of the heart. Since DAF is abundantly expressed in epithelial an…

Paroxysmal nocturnal hemoglobinuria-like phenotype and thrombotic risk in several clinical disorders.

2021

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…