The Experts below are selected from a list of 126 Experts worldwide ranked by ideXlab platform
John L. Mcgregor - One of the best experts on this subject based on the ideXlab platform.
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Characterization of two vaccinia CD36 recombinant-virus-generated monoclonal antibodies (10/5, 13/10): effects on malarial cytoadherence and platelet functions.
European journal of biochemistry, 1997Co-Authors: Laurent Daviet, Alister Craig, Lilian Mcgregor, Robert Pinches, T F Wild, Anthony R. Berendt, Chris I. Newbold, John L. McgregorAbstract:Extensive evidence is now available to show that the human CD36 Antigen is a cellular receptor for thrombospondin, collagen, modified low-density lipoproteins, and long-chain fatty acids. Moreover, CD36 functions as one of the receptors that mediates the adhesion of Plasmodium-falciparum-infected erythrocytes to microvascular endothelium. In an attempt to identify new functional sites of this surface glycoprotein, anti-CD36 monoclonal antibodies were prepared using a vaccinia CD36 recombinant virus as a highly efficient immunization vector. In functional studies, one of these antibodies (clone 10/5) strongly inhibited the adhesion of P. falciparum-infected erythrocytes to purified CD36. This antibody also potentiated ADP-induced platelet activation. In contrast, a second antibody (clone 13/10) did not affect the cytoadherence of infected erythrocytes or platelet functions. Previous structural work performed on these antibodies has shown that clone 10/5 is directed against an epitope within the CD36 domain 155-183, whereas clone 13/10 interacts with another Antigenic determinant defined by amino acids 30-76 [Daviet, L., Buckland, R., Puente Navazo, M. D. & McGregor, J. L. (1995) Biochem. J. 305, 221-224]. Taken together, these current studies show that: (a) the methodology of immunization using recombinant vaccinia virus is a powerful tool in the generation of monoclonal antibodies directed against polyimmunogenic membrane glycoproteins such as CD36; (b) the CD36 domain, recognized by clone 10/5 but not by 13/10, is functionnally important regarding the adhesion of P. falciparum-infected erythrocyte and CD36-dependent platelet activation.
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Vascular biology of CD36 : Roles of this new adhesion molecule family in different disease states
Thrombosis and haemostasis, 1997Co-Authors: Laurent Daviet, John L. McgregorAbstract:The human CD36 Antigen is a scavenger receptor and a celladhesion molecule expressed by platelets, monocytes and microvascular endothelial cells, among other cell types. It belongs to a new and growing family of integral membrane glycoproteins that recognize a wide range of ligands. CD36 has been implicated in hemostasis, thrombosis, malaria, inflammation, lipid metabolism and atherogenesis. Recently, significant advances in CD36 biology have been reported and new CD36-like proteins have been identified.
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Identification of an immunodominant functional domain on human CD36 Antigen using human-mouse chimaeric proteins and homologue-replacement mutagenesis.
Biochemical Journal, 1995Co-Authors: Laurent Daviet, Robin Buckland, M D Puente Navazo, John L. McgregorAbstract:The human CD36 Antigen is a multifunctional membrane glycoprotein that acts as a receptor for thrombospondin, malaria-infected erythrocytes and oxidized low-density lipoprotein, as well as being implicated in the recognition of apoptotic neutrophils by macrophages. OKM5 and other anti-CD36 monoclonal antibodies have been shown to inhibit these CD36 adhesive functions, suggesting that the monoclonal-antibody epitopes and the domains that mediate these events are closely related. Analysis of a series of chimaeric exchanges between human and mouse CD36 shows that six anti-CD36 monoclonal antibodies (OKM5, FA6-152, L103, 5F1, SM phi and 10/5) recognize epitopes within the domain comprising amino acids 155-183. A seventh monoclonal antibody (13/10) binds to another domain that spans amino acids 30-76. Homologue-replacement mutagenesis performed within the human 155-183 immunodominant sequence identifies key residues for the binding of three functional monoclonal antibodies (OKM5, FA6-152 and L103). The fact that antibodies directed against the 155-183 domain can inhibit adhesion suggests that this domain is directly involved in CD36-ligand binding.
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A structural/functional domain on human CD36 is involved in the binding of anti-Nak(a) antibodies.
Thrombosis and haemostasis, 1995Co-Authors: Laurent Daviet, Marie-christine Morel-kopp, Cécile Kaplan, John L. McgregorAbstract:Abstract The human CD36 Antigen is an integral membrane glycoprotein expressed by platelets, monocytes, endothelial cells and various tumor cell lines. CD36 acts as a receptor for thrombospondin, collagen, Plasmodium falciparum-infected erythrocytes and oxidized low-density lipoprotein. Individuals possessing the Nak(a)-negative phenotype do not express CD36 and risk developing anti-CD36 isoantibodies upon blood transfusion or during pregnancy. In the present study, we have examined the interaction of an anti-Nak(a) serum with recombinantly expressed CD36. Results obtained show that five functional CD36 monoclonal antibodies (OKM5, FA6-152, L103, ESIV-C7 and 10/5) prevent the binding of the anti-Nak(a) serum whereas a single monoclonal antibody (13/10) has no effect. Consistent with this result, an epitope map of CD36 generated using cross-blocking experiments, indicates that the inhibitory monoclonal antibodies recognize closely-related epitopes whereas 13/10 reacts with a distinct CD36 determinant. Furthermore, we have demonstrated, in a recent study, that OKM5, FA6-152, L103 and 10/5 bind to the same CD36 domain defined by amino acids 155 to 183. Taken together, our results indicate that the 155-183 sequence is important for the binding of the anti-Nak(a) serum to CD36 and may represent a surface-exposed, immunogenic and presumably functional region on human CD36.
Laurent Daviet - One of the best experts on this subject based on the ideXlab platform.
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Characterization of two vaccinia CD36 recombinant-virus-generated monoclonal antibodies (10/5, 13/10): effects on malarial cytoadherence and platelet functions.
European journal of biochemistry, 1997Co-Authors: Laurent Daviet, Alister Craig, Lilian Mcgregor, Robert Pinches, T F Wild, Anthony R. Berendt, Chris I. Newbold, John L. McgregorAbstract:Extensive evidence is now available to show that the human CD36 Antigen is a cellular receptor for thrombospondin, collagen, modified low-density lipoproteins, and long-chain fatty acids. Moreover, CD36 functions as one of the receptors that mediates the adhesion of Plasmodium-falciparum-infected erythrocytes to microvascular endothelium. In an attempt to identify new functional sites of this surface glycoprotein, anti-CD36 monoclonal antibodies were prepared using a vaccinia CD36 recombinant virus as a highly efficient immunization vector. In functional studies, one of these antibodies (clone 10/5) strongly inhibited the adhesion of P. falciparum-infected erythrocytes to purified CD36. This antibody also potentiated ADP-induced platelet activation. In contrast, a second antibody (clone 13/10) did not affect the cytoadherence of infected erythrocytes or platelet functions. Previous structural work performed on these antibodies has shown that clone 10/5 is directed against an epitope within the CD36 domain 155-183, whereas clone 13/10 interacts with another Antigenic determinant defined by amino acids 30-76 [Daviet, L., Buckland, R., Puente Navazo, M. D. & McGregor, J. L. (1995) Biochem. J. 305, 221-224]. Taken together, these current studies show that: (a) the methodology of immunization using recombinant vaccinia virus is a powerful tool in the generation of monoclonal antibodies directed against polyimmunogenic membrane glycoproteins such as CD36; (b) the CD36 domain, recognized by clone 10/5 but not by 13/10, is functionnally important regarding the adhesion of P. falciparum-infected erythrocyte and CD36-dependent platelet activation.
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Vascular biology of CD36 : Roles of this new adhesion molecule family in different disease states
Thrombosis and haemostasis, 1997Co-Authors: Laurent Daviet, John L. McgregorAbstract:The human CD36 Antigen is a scavenger receptor and a celladhesion molecule expressed by platelets, monocytes and microvascular endothelial cells, among other cell types. It belongs to a new and growing family of integral membrane glycoproteins that recognize a wide range of ligands. CD36 has been implicated in hemostasis, thrombosis, malaria, inflammation, lipid metabolism and atherogenesis. Recently, significant advances in CD36 biology have been reported and new CD36-like proteins have been identified.
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Identification of an immunodominant functional domain on human CD36 Antigen using human-mouse chimaeric proteins and homologue-replacement mutagenesis.
Biochemical Journal, 1995Co-Authors: Laurent Daviet, Robin Buckland, M D Puente Navazo, John L. McgregorAbstract:The human CD36 Antigen is a multifunctional membrane glycoprotein that acts as a receptor for thrombospondin, malaria-infected erythrocytes and oxidized low-density lipoprotein, as well as being implicated in the recognition of apoptotic neutrophils by macrophages. OKM5 and other anti-CD36 monoclonal antibodies have been shown to inhibit these CD36 adhesive functions, suggesting that the monoclonal-antibody epitopes and the domains that mediate these events are closely related. Analysis of a series of chimaeric exchanges between human and mouse CD36 shows that six anti-CD36 monoclonal antibodies (OKM5, FA6-152, L103, 5F1, SM phi and 10/5) recognize epitopes within the domain comprising amino acids 155-183. A seventh monoclonal antibody (13/10) binds to another domain that spans amino acids 30-76. Homologue-replacement mutagenesis performed within the human 155-183 immunodominant sequence identifies key residues for the binding of three functional monoclonal antibodies (OKM5, FA6-152 and L103). The fact that antibodies directed against the 155-183 domain can inhibit adhesion suggests that this domain is directly involved in CD36-ligand binding.
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A structural/functional domain on human CD36 is involved in the binding of anti-Nak(a) antibodies.
Thrombosis and haemostasis, 1995Co-Authors: Laurent Daviet, Marie-christine Morel-kopp, Cécile Kaplan, John L. McgregorAbstract:Abstract The human CD36 Antigen is an integral membrane glycoprotein expressed by platelets, monocytes, endothelial cells and various tumor cell lines. CD36 acts as a receptor for thrombospondin, collagen, Plasmodium falciparum-infected erythrocytes and oxidized low-density lipoprotein. Individuals possessing the Nak(a)-negative phenotype do not express CD36 and risk developing anti-CD36 isoantibodies upon blood transfusion or during pregnancy. In the present study, we have examined the interaction of an anti-Nak(a) serum with recombinantly expressed CD36. Results obtained show that five functional CD36 monoclonal antibodies (OKM5, FA6-152, L103, ESIV-C7 and 10/5) prevent the binding of the anti-Nak(a) serum whereas a single monoclonal antibody (13/10) has no effect. Consistent with this result, an epitope map of CD36 generated using cross-blocking experiments, indicates that the inhibitory monoclonal antibodies recognize closely-related epitopes whereas 13/10 reacts with a distinct CD36 determinant. Furthermore, we have demonstrated, in a recent study, that OKM5, FA6-152, L103 and 10/5 bind to the same CD36 domain defined by amino acids 155 to 183. Taken together, our results indicate that the 155-183 sequence is important for the binding of the anti-Nak(a) serum to CD36 and may represent a surface-exposed, immunogenic and presumably functional region on human CD36.
Nobuo Okumura - One of the best experts on this subject based on the ideXlab platform.
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Cell surface Antigen expression in human erythroid progenitors: erythroid and megakaryocytic markers.
Leukemia & lymphoma, 1994Co-Authors: Tatsutoshi Nakahata, Nobuo OkumuraAbstract:This review summarizes the changes in cell surface Antigen expression during proliferation and differentiation of human erythroid progenitors. The content is based on our experimental data obtained from complement-mediated cytotoxicity assays against hematopoietic progenitors and a combined technique of sequential micromanipulations of paired daughter cells derived from erythroid burst-forming units (BFU-E) and immunostaining with a panel of monoclonal antibodies, as well as from current information. BFU-E has CD34, CD41a (platelet glycoprotein[GP]IIb/IIIa) and CD41b(GPIIb) Antigens. Paired daughter cells derived from BFU-E have CD41a, CD41b, CD71 (transferrin receptor) and HLA-DR Antigens, but not CD34 or CD33 Antigen. The CD36 Antigen (thrombospondin receptor or GPIV) is first expressed on the cells after 5 days of culture, in agreement with the report that the anti-CD36 positive fraction contained a greater part of the erythroid colony-forming units (CFU-E). The blood group A Antigen is first expressed on cells from aggregates derived from BFU-E after 5 days of culture. Glycophorin A is expressed on cell surface after 7 days of culture when proerythroblasts first appear. Hemoglobin alpha is expressed after 8 days of culture and coincides with the first appearance of basophilic erythroblasts. This review provides useful information on the identification of leukemic cells from poorly differentiated acute leukemias such as early erythroblastic leukemia and acute megakaryoblastic leukemia, and is useful in the understanding of the commitment and differentiation of erythroid and megakaryocytic progenitors in normal hematopoiesis.
Xinxin Ding - One of the best experts on this subject based on the ideXlab platform.
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Hepatic Gene Expression Changes in Mouse Models with Liver-specific Deletion or Global Suppression of the NADPH-Cytochrome P450 Reductase Gene MECHANISTIC IMPLICATIONS FOR THE REGULATION OF MICROSOMAL CYTOCHROME P450 AND THE FATTY LIVER PHENOTYPE
The Journal of biological chemistry, 2005Co-Authors: Yan Weng, Concetta Dirusso, Andrew A. Reilly, Paul N. Black, Xinxin DingAbstract:NADPH-cytochrome P450 reductase (CPR) is an essential component for the function of many enzymes, including microsomal cytochrome P450 (P450) monooxygenases and heme oxygenases. In liver-Cpr-null (with liver-specific Cpr deletion) and Cpr-low (with reduced CPR expression in all organs examined) mouse models, a reduced serum cholesterol level and an induction of hepatic P450s were observed, whereas hepatomegaly and fatty liver were only observed in the liver-Cpr-null model. Our goal was to identify hepatic gene expression changes related to these phenotypes. Cpr-lox mice (with a floxed Cpr gene and normal CPR expression) were used as the control. Through microarray analysis, we identified many genes that were differentially expressed among the three groups of mice. We also recognized the 12 gene ontology terms that contained the most significantly changed gene expression in at least one of the two mouse models. We further uncovered potential mechanisms, such as an increased activation of constitutive androstane receptor and a decreased activation of peroxisomal proliferator-activated receptor-alpha by precursors of cholesterol biosynthesis, that underlie common changes (e.g. induction of multiple P450s and suppression of genes for fatty acid metabolism) in response to CPR loss in the two mouse models. Additionally, we observed model-specific gene expression changes, such as the induction of a fatty-acid translocase (CD36 Antigen) and the suppression of carnitine O-palmitoyltransferase 1 (Cpt1a) and acyl-CoA synthetase long chain family member 1 (Acsl1), that are potentially responsible for the severe hepatic lipidosis and an altered fatty acid profile observed in liver-Cpr-null mice.
Gang Chen - One of the best experts on this subject based on the ideXlab platform.
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Abstract 101: Human bone marrow-derived endothelial progenitor cells promote the transformation of periostin-positive hepatocellular carcinoma cells into CD36-positive metastasis-initialing cells in pre-metastatic niche
Tumor Biology, 2018Co-Authors: Xiaozai Xie, Pengyi Guo, Yi Wang, Gang ChenAbstract:BACKGROUND: Recent studies have shown that metastasis-initiating cells (MICs) in the pre-metastatic niche play a key role in triggering tumor metastasis. In addition, bone marrow-derived endothelial progenitor cells (BM-EPCs), which are key components of the pre-metastatic microenvironment, can serve as “metastasis-initiators”. Our previous studies have revealed that the periostin (POSTN) expression in HCC is positively correlated with the amount of EPCs and POSTNhigh hepatocarcinoma cells possess cancer stem cell-like properties. Meanwhile, CD36, a biomarker of MICs, is highly expressed in recurrent HCC. This study aims to clarify whether BM-EPCs in the pre-metastatic niche promote the generation of CD36-positive MICs and stimulate tumor metastasis through interacting with POSTNhigh hepatocarcinoma cells in HCC. AIMS and METHODS: Cell co-culture experiments were conducted to investigate the effect of EPCs on malignant biological behaviors of POSTNhigh hepatocarcinoma cells. In addition, the change in the expression of CD36 antibody in co-cultured HCC cells was evaluated to investigate the generation of CD36-positive MICs. Furthermore, NF-E2-related factor 2 (Nrf2) was identified as a transcription factor that increases the expression of CD36 Antigen and promotes stem cell-like properties of HCC cells. Finally, the changes in HCC invasion and metastasis by manipulating the POSTN/Nrf2/CD36 signal axis were evaluated. RESULTS: POSTNhigh HCC cells co-cultured with EPCs showed enhanced proliferation, invasion and spheroid formation. Flow cytometry demonstrated that the expression level of CD36 on cell surface was significantly up-regulated in these co-cultured cells. ELISA tests showed that CCL2 secreted by EPCs was the key factor promoting the transformation of POSTNhigh HCC cells to a CD36-positive phenotype. Further experiments revealed that, after binding to the CCR2 receptor on HCC cell membrane, EPC-secreted CCL2 promoted the direct binding of Nrf2 to the promoter region of CD36 gene and upregulated CD36 expression when the αvβ3 pathway was activated, which eventually induced the transformation of POSTNHigh HCC cells into CD36-expressing MICs. The CCL2 monoclonal antibody and αvβ3 antagonist Cilengitide effectively blocked the POSTN/Nrf2 /CD36 axis, inhibiting the formation of CD36-positive MICs of HCC and suppressing tumor invasion and metastasis. CONCLUSIONS: CCL2 protein secreted by BM-EPCs can promote the transformation of POSTNhigh HCC cells into CD36-positive MICs, thereby promoting formation of metastases. Citation Format: Xiaozai Xie, Pengyi Guo, Haitao Yu, Yi Wang, Gang Chen. Human bone marrow-derived endothelial progenitor cells promote the transformation of periostin-positive hepatocellular carcinoma cells into CD36-positive metastasis-initialing cells in pre-metastatic niche [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 101.