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B P Morgan - One of the best experts on this subject based on the ideXlab platform.
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the complement inhibiting protein protectin CD59 Antigen is present and functionally active on glomerular epithelial cells
Clinical and Experimental Immunology, 2008Co-Authors: I A Rooney, A Davies, David J Griffiths, John D Williams, Malcolm Davies, Seppo Meri, P J Lachmann, B P MorganAbstract:Protectin (CD59 Antigen) is a 20-kD phosphatidyl-inositol-linked membrane protein that inhibits formation of the membrane attack complex (MAC) of complement on homologous cells. Although the Antigen has been identified in a number of human tissues, until recently a functional role had been demonstrated only in circulating cells. Using immunofluorescence techniques we have shown the presence of protectin on human glomerular epithelial cells (GEC) in culture and on GEC, tubular epithelial cells and endothelial cells in frozen sections of normal human renal cortex. In addition, we present evidence that this protein functions in protection of GEC from homologous complement: cultured cells incubated with the Fab2 fragment of a monoclonal anti-protein antibody were markedly more susceptible to killing by homologous serum than were cells in the absence of Fab2 anti-protectin. These findings suggest that this protein may be important in the maintenance of glomerular integrity in vivo, and may be of relevance in certain renal diseases.
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expression of the glycosylphosphatidylinositol linked complement inhibiting protein CD59 Antigen in insect cells using a baculovirus vector
Biochemical Journal, 1993Co-Authors: A Davies, B P MorganAbstract:CD59 Antigen (CD59) is a glycosylphosphatidylinositol (GPI)-linked membrane glycoprotein which protects human cells from complement-mediated lysis. Here we report the expression of functionally active CD59 in Spodoptera frugiperda insect cells using a baculovirus vector. Recombinant CD59 was expressed abundantly on the surface of the insect cells and protected the cells from lysis by human complement. The protein was released from the cell surface by treatment with phosphatidylinositol-specific phospholipase C, indicating that it was attached to the insect cell membrane via a GPI anchor. The cells also secreted CD59 into the culture medium. Recombinant CD59 was affinity-purified from spent culture medium and from detergent extract of transfected cells. Protein purified from both sources produced multiple bands on SDS/PAGE, all of a lower apparent molecular mass than the human erythrocyte protein. However, N-terminal protein sequencing and deglycosylation studies confirmed that signals for leader peptide cleavage and N-linked glycosylation had been recognized in the insect cells, suggesting that the differences in apparent molecular mass between the native and recombinant proteins were attributable to the extent of glycosylation. Protein derived from both sources was, in part, GPI-anchored as demonstrated by phase-partition studies and incorporation into cells membranes. Incorporated recombinant protein rendered erythrocytes resistant to complement lysis.
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characterization of the membrane attack complex inhibitory protein CD59 Antigen on human amniotic cells and in amniotic fluid
Immunology, 1992Co-Authors: I A Rooney, B P MorganAbstract:A functional complement system and the potential for its activation are present in human amniotic fluid. We have recently demonstrated that CD59 Antigen is present and functionally active on human amniotic epithelial cells (HAEC). We have now further examined the role of this protein on HAEC and have also demonstrated its presence in amniotic fluid (AF). CD59 Ag on HAEC is similar in size to the erythrocyte protein and is anchored via glycosyl phosphatidylinositol. The AF protein retained the capacity to incorporate into target cells and protect against lysis by complement. These data suggest that HAEC secrete into AF a form of CD59 Ag which retains inhibitory activity and which may be important in protection of the foetus from maternal complement in utero.
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isolation and characterization of the complement inhibiting protein CD59 Antigen from platelet membranes
Biochemical Journal, 1992Co-Authors: B P MorganAbstract:Several groups have recently described the isolation of a 20 kDa membrane-attack-complex (MAC)-inhibiting protein, termed 'CD59 Antigen', from human erythrocyte membranes. Antibodies raised against erythrocyte CD59 Antigen detect Antigen on the surface of many other cell types, and in some of these cells the Antigen has been shown to have a molecular mass similar to that of the erythrocyte protein and to confer resistance to lysis by the MAC. A platelet-membrane form of CD59 Antigen has been described and reported to be much larger than the erythrocyte protein. Here I report the isolation of CD59 Antigen from platelet membranes and its molecular and functional characterization. The platelet protein is not significantly larger than the erythrocyte form and possesses similar MAC-inhibiting activity. Platelet CD59 Antigen is anchored to the membrane via a glycosyl-phosphatidylinositol link, and consequently it is suggested that deficiency of this protein might be responsible for the increased thrombotic tendency observed in paroxysmal nocturnal haemoglobinuria.
I A Rooney - One of the best experts on this subject based on the ideXlab platform.
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the complement inhibiting protein protectin CD59 Antigen is present and functionally active on glomerular epithelial cells
Clinical and Experimental Immunology, 2008Co-Authors: I A Rooney, A Davies, David J Griffiths, John D Williams, Malcolm Davies, Seppo Meri, P J Lachmann, B P MorganAbstract:Protectin (CD59 Antigen) is a 20-kD phosphatidyl-inositol-linked membrane protein that inhibits formation of the membrane attack complex (MAC) of complement on homologous cells. Although the Antigen has been identified in a number of human tissues, until recently a functional role had been demonstrated only in circulating cells. Using immunofluorescence techniques we have shown the presence of protectin on human glomerular epithelial cells (GEC) in culture and on GEC, tubular epithelial cells and endothelial cells in frozen sections of normal human renal cortex. In addition, we present evidence that this protein functions in protection of GEC from homologous complement: cultured cells incubated with the Fab2 fragment of a monoclonal anti-protein antibody were markedly more susceptible to killing by homologous serum than were cells in the absence of Fab2 anti-protectin. These findings suggest that this protein may be important in the maintenance of glomerular integrity in vivo, and may be of relevance in certain renal diseases.
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characterization of the membrane attack complex inhibitory protein CD59 Antigen on human amniotic cells and in amniotic fluid
Immunology, 1992Co-Authors: I A Rooney, B P MorganAbstract:A functional complement system and the potential for its activation are present in human amniotic fluid. We have recently demonstrated that CD59 Antigen is present and functionally active on human amniotic epithelial cells (HAEC). We have now further examined the role of this protein on HAEC and have also demonstrated its presence in amniotic fluid (AF). CD59 Ag on HAEC is similar in size to the erythrocyte protein and is anchored via glycosyl phosphatidylinositol. The AF protein retained the capacity to incorporate into target cells and protect against lysis by complement. These data suggest that HAEC secrete into AF a form of CD59 Ag which retains inhibitory activity and which may be important in protection of the foetus from maternal complement in utero.
A Davies - One of the best experts on this subject based on the ideXlab platform.
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the complement inhibiting protein protectin CD59 Antigen is present and functionally active on glomerular epithelial cells
Clinical and Experimental Immunology, 2008Co-Authors: I A Rooney, A Davies, David J Griffiths, John D Williams, Malcolm Davies, Seppo Meri, P J Lachmann, B P MorganAbstract:Protectin (CD59 Antigen) is a 20-kD phosphatidyl-inositol-linked membrane protein that inhibits formation of the membrane attack complex (MAC) of complement on homologous cells. Although the Antigen has been identified in a number of human tissues, until recently a functional role had been demonstrated only in circulating cells. Using immunofluorescence techniques we have shown the presence of protectin on human glomerular epithelial cells (GEC) in culture and on GEC, tubular epithelial cells and endothelial cells in frozen sections of normal human renal cortex. In addition, we present evidence that this protein functions in protection of GEC from homologous complement: cultured cells incubated with the Fab2 fragment of a monoclonal anti-protein antibody were markedly more susceptible to killing by homologous serum than were cells in the absence of Fab2 anti-protectin. These findings suggest that this protein may be important in the maintenance of glomerular integrity in vivo, and may be of relevance in certain renal diseases.
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expression of the glycosylphosphatidylinositol linked complement inhibiting protein CD59 Antigen in insect cells using a baculovirus vector
Biochemical Journal, 1993Co-Authors: A Davies, B P MorganAbstract:CD59 Antigen (CD59) is a glycosylphosphatidylinositol (GPI)-linked membrane glycoprotein which protects human cells from complement-mediated lysis. Here we report the expression of functionally active CD59 in Spodoptera frugiperda insect cells using a baculovirus vector. Recombinant CD59 was expressed abundantly on the surface of the insect cells and protected the cells from lysis by human complement. The protein was released from the cell surface by treatment with phosphatidylinositol-specific phospholipase C, indicating that it was attached to the insect cell membrane via a GPI anchor. The cells also secreted CD59 into the culture medium. Recombinant CD59 was affinity-purified from spent culture medium and from detergent extract of transfected cells. Protein purified from both sources produced multiple bands on SDS/PAGE, all of a lower apparent molecular mass than the human erythrocyte protein. However, N-terminal protein sequencing and deglycosylation studies confirmed that signals for leader peptide cleavage and N-linked glycosylation had been recognized in the insect cells, suggesting that the differences in apparent molecular mass between the native and recombinant proteins were attributable to the extent of glycosylation. Protein derived from both sources was, in part, GPI-anchored as demonstrated by phase-partition studies and incorporation into cells membranes. Incorporated recombinant protein rendered erythrocytes resistant to complement lysis.
P J Lachmann - One of the best experts on this subject based on the ideXlab platform.
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the complement inhibiting protein protectin CD59 Antigen is present and functionally active on glomerular epithelial cells
Clinical and Experimental Immunology, 2008Co-Authors: I A Rooney, A Davies, David J Griffiths, John D Williams, Malcolm Davies, Seppo Meri, P J Lachmann, B P MorganAbstract:Protectin (CD59 Antigen) is a 20-kD phosphatidyl-inositol-linked membrane protein that inhibits formation of the membrane attack complex (MAC) of complement on homologous cells. Although the Antigen has been identified in a number of human tissues, until recently a functional role had been demonstrated only in circulating cells. Using immunofluorescence techniques we have shown the presence of protectin on human glomerular epithelial cells (GEC) in culture and on GEC, tubular epithelial cells and endothelial cells in frozen sections of normal human renal cortex. In addition, we present evidence that this protein functions in protection of GEC from homologous complement: cultured cells incubated with the Fab2 fragment of a monoclonal anti-protein antibody were markedly more susceptible to killing by homologous serum than were cells in the absence of Fab2 anti-protectin. These findings suggest that this protein may be important in the maintenance of glomerular integrity in vivo, and may be of relevance in certain renal diseases.
Seppo Meri - One of the best experts on this subject based on the ideXlab platform.
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the complement inhibiting protein protectin CD59 Antigen is present and functionally active on glomerular epithelial cells
Clinical and Experimental Immunology, 2008Co-Authors: I A Rooney, A Davies, David J Griffiths, John D Williams, Malcolm Davies, Seppo Meri, P J Lachmann, B P MorganAbstract:Protectin (CD59 Antigen) is a 20-kD phosphatidyl-inositol-linked membrane protein that inhibits formation of the membrane attack complex (MAC) of complement on homologous cells. Although the Antigen has been identified in a number of human tissues, until recently a functional role had been demonstrated only in circulating cells. Using immunofluorescence techniques we have shown the presence of protectin on human glomerular epithelial cells (GEC) in culture and on GEC, tubular epithelial cells and endothelial cells in frozen sections of normal human renal cortex. In addition, we present evidence that this protein functions in protection of GEC from homologous complement: cultured cells incubated with the Fab2 fragment of a monoclonal anti-protein antibody were markedly more susceptible to killing by homologous serum than were cells in the absence of Fab2 anti-protectin. These findings suggest that this protein may be important in the maintenance of glomerular integrity in vivo, and may be of relevance in certain renal diseases.