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J Le Pendu

Publications and source records attributed to J Le Pendu.

At least 55 records · Page 3Linked to original sources
PubMed1991

Analysis of the state of differentiation of two rat colon carcinoma clones with distinct tumorigenic properties.

The presence of some characteristics of normal rat intestinal epithelial cells was studied on two clones originating from a single rat colon carcinoma. These clones differed by their tumorigenic properties in the syngeneic host. However, they grow similarly in vitro and in immuno-deprived animals. The PROb clone which had the ability to form progressive tumors in the syngeneic host appeared to possess more features of differentiated cells than the REGb clone which was immunologically rejected by syngeneic hosts. Indeed, the morphology of the cells was different, the REBb cells having a more fibroblastic appearance while the PROb cells had the capacity to form domes characterizing the functional polarization of the cell layer. The two clones could also be distinguished by their expression of proteins of intermediate filaments. Both expressed cytokeratins showing their epithelial origin, but only REGb cells displayed vimentin which is characteristic of mesenchymal or poorly differentiated epithelial cells. Furthermore, analysis of the expression of a series of glycoconjugate tissue antigens and an unknown protein (p120) showed that the PROb cells resembled more the normal adult digestive epithelium than the REGb cells did. In conclusion, it appears that in this model, the most aggressive cells, those resisting to the constraints imposed by the immune system, are also the more differentiated ones.

Adenocarcinoma↗
PubMed1990

Correlation between cell surface oligosaccharides and tissue target-selective adhesion of two rat adenocarcinoma cell lines.

We observed that two rat colon adenocarcinoma variants originating from a single parental cell line and differing by their progressive and metastatic capacities in syngeneic BDIX rats differed by their organ distribution after intravenous injections. The PROb cells accumulated in the lung, wherefrom the REGb cells were rapidly cleared. In order to explore the role of cell surface glycoconjugates in organ-specific metastasis, cytofluorometric and histochemical studies using labelled lectins were performed. This revealed that the metastatic variant PROb presented more alpha-L-Fuc(1----2) beta D-Gal-R structures than the regressive nonmetastatic variant REGb. At variance, REGb cells exposed more D-galactosyl and N-acetyl-D-galactosaminyl residues than PROb cells. Monosacharides inhibited specifically cell adhesions on frozen organ sections. L-Fuc and N-acetyl-D-galactosamine (D-GalNAc) most strongly inhibited the adhesion of PROb cells on lungs, whereas D-Gal and D-GalNAc most strongly inhibited that of REGb cells. On the liver, adhesions of both cell lines were inhibited by D-Gal and D-GalNAc. These observations support the involvement of sugar-lectin receptors in the adhesion of these cells to the lungs or liver. The possible involvement of previously described lectins is discussed.

Adenocarcinoma↗
PubMed1989

Cellular expression of H and B antigens in the rat olfactory system during development.

Developmental expression of H and B antigens in the rat olfactory system was studied from the embryonic day 14 up to the postnatal day 30. The H antigen was detected in the olfactory and vomeronasal epithelia as early as fetal day 14, whereas the B antigen first appeared 2 days later. The anti-H reagent reacted strongly with sensory receptors and weakly with supporting cells in both epithelia, whereas the anti-B reagent was specific for olfactory receptors. In the main olfactory epithelium, the H antigen was expressed from fetal day 19 by most of the receptor cells, whereas the B determinant was expressed from fetal day 16 to postnatal day 3 by only a few neuroreceptors mostly located near the epithelial surface. After the postnatal day 3, B positive neurons increased in number from the periphery toward the deeper mucosal layers and they were distributed over 3/4 of the epithelial thickness in 15- and 30-day-old rats. In the main olfactory bulb, a widespread glomerular B staining with variable binding intensity between adjacent glomeruli was already observed at birth. The vomeronasal receptor cells and their axon terminals in the accessory olfactory bulb exhibited a comparable developmental expression of the B antigen. Results suggest that the B antigen could be regarded as a marker of neuronal maturation of both the olfactory and vomeronasal receptor cells; moreover, its first appearance in the receptor cells might be temporally related to the formation of synapses between receptor axons and deutoneurons in the bulb.

ABO Blood-Group System↗
PubMed1989

Expression of ABH, Lewis and related tissue antigens in the human thymus.

Expression of ABH, Lewis and related antigens was studied in the thymus of children of known ABO, Lewis and secretor status using a panel of specific reagents. ABH and Lewis antigens partly under control of the secretor status were expressed on the Hassals' bodies and a large fraction of the medullary epithelial cells. The sialyl-Lea antigen was only present on some Hassals' bodies of Lewis-positive individuals. ABH but not Lewis antigens were also present on cortical epithelial cells but this was independent of the secretor status. The X, sialyl-X and Y antigens were only expressed on Hassals' bodies irrespective of the ABO, Lewis or secretor phenotype. Furthermore, the anti-X and sialyl-X antibodies labelled a subset of leucocytes of all the individuals tested. These results show that the genetic control of the expression of ABH and Lewis glycosidic tissue alloantigens in the thymus is different on cortical and medullary epithelial cells and stress the heterogeneity of the thymus epithelial cells.

ABO Blood-Group System↗
PubMed1989

A hypothesis on the dual significance of ABH, Lewis and related antigens.

ABH and related antigens appeared a long time ago in the evolution of vertebrates on tissues in contact with the external environment, which suggests that the polymorphism given by these antigens might play a role in the relationships of the species with pathogens. However, they are also oncodevelopmental markers and some recent experimental data suggest that they might play a role in cell-cell recognition at some stages of development. This type of function is difficult to reconcile with the polymorphic nature of these markers unless one considers that the glycosyltransferases necessary for the synthesis of the active structures are encoded by various members of multigene families. Some non-polymorphic members of the families would have their expression limited in time and space during development, leading to the same antigenic patterns in every individual, and these could reappear in some tumours, while the expression of other polymorphic members (A/B/O, H/h, Se/se, Le/le), leading to a variety of antigenic phenotypes, would be expressed at later stages and remain so during the whole life of the individual. The corresponding antigens could disappear from some cancer cells. It is argued that the ABH and related antigens would have primarily been involved in cell-cell recognition phenomena. The polymorphism would have evolved later from gene duplication under environmental pressure, the expression on erythrocytes which occurred very late in evolutionary time probably being of very little biological significance.

ABO Blood-Group System↗
PubMed1988

Immunochemical characterization of mucins. Polypeptide (M1) and polysaccharide (A and Leb) antigens.

Seven monoclonal antibodies (MAbs) reacting with high-molecular-mass components (greater than 20,000 kDa) isolated from an ovarian mucinous cyst of an A Le(a-b+) patient are described. By the use of immunoradiometric methods, these MAbs characterized seven different epitopes associated with components having a density of 1.45 g/ml by CsCl-density-gradient ultracentrifugation, like mucins. Two MAbs reacted with A and Lewis blood-group antigens respectively (polysaccharide epitopes). The five other MAbs characterized five M1 epitopes (called a, b, c, d and e), mainly associated with components of more than 20,000 kDa and 2000 kDa. They were completely destroyed by papain and 2-mercaptoethanol treatment (polypeptide epitopes). Moreover, timed trypsin digestion of native mucin resulted in a progressive loss of M1 activity and degraded these mucins into smaller M1-positive fragments. The a and c epitopes were partially degraded from relatively high-molecular-mass fragments (2000 kDa to 500 kDa) into a 100 kDa fragment. The b and d epitopes were completely degraded into smaller fragments ranging from 100 kDa to 40 kDa. The e epitope was completely destroyed by trypsin. These different pathways of M1 antigen degradation suggest the occurrence of different epitopes located in separate regions of the mucin molecules.

Antibodies, Monoclonal↗
PubMed1988

A new mucin-associated oncofetal antigen, a marker of early carcinogenesis in rat colon.

We report the characterization of an IgG2a monoclonal antibody, (MAb) 660, prepared against rat gastric high molecular weight glycoproteins. By immunoperoxidase staining, MAb 660 reacted only with the mucous cells of surface gastric epithelium and with a few duodenal goblet cells close to the pylorus in normal adult rats. In fetuses, it reacted with intestinal and colonic goblet cells. The adult colon was always negative. The MAb 660 stained 100% (30 of 30) of chemically induced colonic carcinomas and 100% (7 of 7) of duodenal carcinomas. Several weeks before the appearance of tumors, histologically normal glands, then hyperplasia and dysplasia were precociously stained with MAb 660. The tissue distribution was different from that of blood group related antigens and M1 fucomucins. The recognized antigen was not sensitive to neuraminidase treatment. After electrophoresis in polyacrylamide gel, staining with periodic acid-Schiff reagent and Western blotting showed that the MAb 660 recognized an epitope associated with high molecular weight glycoproteins. This epitope was unaffected by beta-mercaptoethanol reduction-periodate treatment and neuraminidase and trypsin digestion. However, trypsin digestion performed after beta-mercaptoethanol reduction destroyed the 660 epitope. These data suggest that the antibody could recognize the peptide moiety of the mucin rather than its carbohydrate moiety. Thus, the new antigen identified by MAb 660 is a mucin-type glycoprotein with an oncofetal behavior in the rat colon and is precociously expressed by precancerous colonic mucosa.

Animals↗
PubMed1988

Expression of ABH and X (Lex) antigens in various cells.

Using a panel of reagents specific to the various subtypes of ABH antigens, it could be demonstrated that platelets carry ABH type 2 monofucosylated determinants on intrinsic glycoproteins. The presence of these antigens is controlled by the H gene and correlates with the presence of alpha-2-L-fucosyltransferase and the absence of alpha-3-L-fucosyltransferase. In contrast, intrinsic ABH antigens were not found on mononuclear cells, correlating with the absence of alpha-2-L-fucosyltransferase on these cells. However, after transformation with the Epstein-Barr virus and stimulation with 12-O-tetradecanoylphorbol-13-O-acetate (TPA), B lymphocytes were found to express the H antigen under control of the H gene and not the Se gene. The lymphoblastoid cell lines also expressed the X and sialylated X antigens which are normally markers of the myeloid lineage. These antigens are also normally found in epithelial cells of the digestive tract, kidney proximal convoluted tubules and hepatocytes. The alpha-3-L-fucosyltransferase responsible for the synthesis of this antigen is present in the serum but we report the existence of two individuals, a mother and her daughter, who lack more than 90% of this serum enzyme. The young girl suffers from a congenital kidney anomaly: oligomeganephronic hypoplasia. Her kidney tubules are devoid of X antigen. However, she and her mother have the X antigen on their granulocytes and its sialylated form on their monocytes. It therefore appears that there are distinct genetic controls for the expression of antigen X in different body compartments. This would be quite similar to the H and Se gene controls in tissues of distinct embryological origins.

ABO Blood-Group System↗
PubMed1988

Use of a simple method for the Epstein-Barr virus transformation of lymphocytes from members of large families of Réunion Island.

A simple method for the preparation of lymphoblastoid cell lines from small amounts (100 microliter) of frozen whole blood is described. A success score greater than 90% was obtained for EBV transformations using blood samples which had been collected several months before the infection. Due to the simplicity of the technique, up to 80 samples could be processed per day. This technique was used to prepared 242 permanent cell lines from 13 large families from Réunion Island showing blood group H deficiency. These cell lines are now available for genetic studies.

ABO Blood-Group System↗
PubMed1988

Demonstration of human kidney differentiation antigens with monoclonal antibodies.

Six human differentiation antigens (EE24.6, EG9.11, EG14.1, EI16.1, EK8.1, EK17.1) have been defined using monoclonal antibodies obtained from mice immunized with embryonic kidney cells. Their histologic distribution was determined on frozen sections of embryonic, fetal, and adult human kidneys by immunofluorescence assay. EE24.6, an ureteral bud marker, was detected only on the germ layer of mature kidney urothelium. EG9.11 and EG14.1 were detected on the S-shaped bodies and also on the adult proximal convoluted tubule for the former and the glomerular basement membrane for the latter. EI16.1, a marker of condensed mesenchyme, was detected only on epithelial cells of adult proximal convoluted tubule. EK8.1 was found in the mesangium, connective tissue, and with particularly dense labeling in the basement membranes. This labeling pattern was present throughout renal organogenesis. EK17.1 recognized both cell and plasma human fibronectins. Staining for all antibodies was nearly identical in mesonephros and metanephros. These results demonstate that some antigens follow their embryonic destiny. They indicate an antigenic similarity between the mesonephros and the metanephros and, therefore, a very early appearance of these antigens. During differentiation, these antigens concentrate on more defined structures, and staining became increased with an increased degree of differentiation.

Antibodies, Monoclonal↗
PubMed1988

Failure of expression of alpha-3-L-fucosyltransferase in human serum is coincident with the absence of the X (or Le(x)) antigen in the kidney but not on leucocytes.

The X antigen, beta Gal(1----4)[alpha Fuc(1----3)]beta GlcNAc-R, is mostly found in epithelial cells of the digestive tract, proximal convoluted tubules of the kidney, and granulocytes. The alpha-3-L-fucosyltransferase responsible for synthesis of this antigen is normally present in the serum, but we found 2 individuals, a mother and her daughter, who lack more than 90% of the serum fucosyltransferase. They are of African origin and are both Le(a-b-). The young girl suffers from a congenital kidney anomaly: oligomeganephronic hypoplasia. Her kidney tubules are devoid of X antigen. However, her mother and herself normally possess the X antigen on granulocytes and its sialylated form on monocytes. Anephric patients showed reduced serum alpha-3-L-fucosyltransferase activity, suggesting that the kidney contributes to an important fraction of serum enzymic activity. It, therefore, appears that there are distinct genetic controls governing expression of the X antigen in different body compartments. Possibly, different alpha-3-L-fucosyltransferases could be at work in kidney and leucocytes.

ABO Blood-Group System↗
PubMed1988

Expression of ABH and X (Lex) antigens on platelets and lymphocytes.

We used a panel of reagents, polyclonal and monoclonal antibodies, and lectins to define the expression of the ABH- and Lewis-related specificities on platelets and lymphocytes. We also determined the expression of the alpha 2- and alpha 3-L-fucosyltransferases necessary for their biosynthesis. The antigens that could be detected by immunofluorescence and Western blot analysis were based on type 2 monofucosylated structures. Antibodies directed toward types 1, 3, and 4 ABH-, X- and Lewis-related antigenic determinants were always negative because the small amounts of ABH and Lewis antigens adsorbed from the serum could not be detected by these techniques. The presence of the type 2 ABH antigens on intrinsic glycoproteins was controlled by the H gene. This correlates with the presence of alpha 2-L-fucosyltransferase and the absence of alpha 3-L-fucosyltransferase on platelets. In contrast, ABH antigens were not detected by immunofluorescence on normal peripheral lymphocytes. These cells thus have only the small amounts of antigens adsorbed from the serum, these being under control of the secretor and Lewis genes. This correlates with the absence of alpha 2-L-fucosyltransferase on lymphocytes. When lymphocytes were transformed in vitro by the Epstein-Barr virus (EBV), however, they strongly expressed the X and sialylated X antigens, which are specific markers of normal granulocytes and monocytes, respectively. Treatment of EBV-transformed lymphoblastoid cell lines with 12-O-tetradecanoylphorbol-13-O-acetate significantly decreased the expression of X and sialylated X antigens along with that of surface immunoglobulins, whereas it induced a significant expression of the H antigen under control of the H gene.

ABO Blood-Group System↗
PubMed1987

Heterogeneity of anti-A and anti-B monoclonal reagents. Agglutination of some weak ABH erythrocyte variants and recognition of synthetic oligosaccharide and tissue antigens.

Eight anti-A and seven anti-B monoclonal reagents were tested in parallel, with normal and weak ABH red cell phenotypes. A whole range of different reactivity patterns was found, but by making a comparison with the results obtained using polyclonal standard reagents, two major categories of reagents were distinguished: (a) stronger and more specific reagents, and (b) reagents similar to, or weaker than, the standard polyclonal controls. The analysis of the specificity of the reagents by tissue fluorescence staining and reactivity with synthetic oligosaccharides and purified glycolipids confirmed the existence of broad and restricted specificities. Two kinds of anti-A1 reagents are described. One related to type 3/4 structures, which stains the Golgi apparatus, and another with broad anti-A specificity which cross-reacts with 'A-like' structures. The inhibition of anti-A reagents with salivas and synthetic oligosaccharide antigens gave parallel results for the secretor salivas and the difucosylated A antigens.

ABO Blood-Group System↗
PubMed1987

Use of monoclonal antibodies to follow the phylogenic distribution of human renal antigens.

Nine human differentiation antigens have been defined by monoclonal antibodies (M. Abs) developed from mice immunized with embryonic kidney cells (mesonephros or metanephros of 7 week-developmental ages). Their spatial and temporal distributions during human kidney organization were previously studied [3]. In this paper we have attempted to follow by immunofluorescence their phylogenic location, from fish to mammals. Six of them recognized the same structures as in humans: proximal convoluted tubules (PCT) (EG9.11, EG19.6, E116.1), glomerular basement membrane (GBM) (EG14.1) and extracellular matrix (EK8.1, EK17.1). However, staining was limited to certain mammals. EK17.1 has been characterized as an anti-fibronectin. These antibodies revealed the same histological structures in the human mesonephros and metanephros. The three other antibodies revealed epitopes appearing earlier in evolution and whose histological distribution varied according to species. These antibodies stained different structures in the mesonephros and metanephros. Thus, the staining particularities observed during human renal ontogenesis were found again in the phylogenetical study.

Animals↗
PubMed1987

Discordance between red cell and saliva Lewis phenotypes in patients with hydatid cysts.

Patients with hydatid cysts and controls of the same Tunisian area were typed for ABO, Lewis and secretor phenotypes. A high incidence of red cell Le(a-b-) phenotype (34-37%) was found among hydatid cyst patients as compared to normal controls (13-16%). However, a large proportion of the patients with Le(a-b-) red cell phenotype had discordant red cell and saliva Lewis phenotypes since they secreted Lea and/or Leb antigens in saliva. In addition, 1 patient with Le(a+b-) red cell phenotype secreted Leb antigen in saliva. The remaining patients and all the controls had concordant red cell and saliva Lewis phenotypes. The discordant results between the phenotypes obtained in serum and saliva of hydatid cyst patients are probably the consequence of a decrease in the concentration of the circulating Lewis glycosphingolipids, secondary to the disease.

ABO Blood-Group System↗
PubMed1986

Genetics of ABO, H, Lewis, X and related antigens.

The present knowledge on chemical, enzymatic, serologic and genetic aspects of ABH antigens is reviewed in an effort to produce a simple and coherent genetic model for the biosynthesis of these antigens and chemically related structures. The genetic control of type 1 (Le(a), Le(b), Le(c) and Le(d)), type 2 (X, Y, I, and H), type 3 and type 4 ABH and related antigens in different animal and human tissues is analyzed, taking into account the properties of the glycosyltransferases which are involved in their synthesis and considering possible competition for common acceptor and donor substrates. The phylogeny of ABH determinants shows that they appeared as tissular antigens much earlier than as red cell antigens. The ontogeny of ABH antigens suggests that they behave as differentiation antigens, and an effort is made to correlate their tissular distribution in the adult with the embryological origin of each tissue.

ABO Blood-Group System↗