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B E Chechik

Publications and source records attributed to B E Chechik.

13 recordsLinked to original sources
PubMed1992

Increased expression of highly branched N-linked oligosaccharides terminating in N-acetylglucosamine residues in neoplastic and sclerodermal chicken fibroblasts.

Although neoplastic cells often show a shift towards the expression of larger N-linked oligosaccharides compared to their normal counterparts, little consideration has been given to the possibility that these changes might be a more general phenomenon characteristic of certain neoplastic and non-neoplastic proliferative disorders. Terminal N-acetylglucosamine (GlcNAc) cluster antigen (TGCA) is an immunoreactive epitope(s) of highly branched N-linked oligosaccharides terminating in GlcNAc residues. Here we have compared the expression of this antigen in normal, neoplastic and sclerodermal chicken fibroblasts by immunomorphological methods. TGCA was detectable in only a few, if any, fibroblasts of normal chicken skin or those cultured from chicken embryos. In contrast, the antigen appeared in 15 to 30% of chicken embryo fibroblasts transformed with avian sarcoma viruses and about 50% of neoplastic fibroblasts of both Rous sarcoma virus-induced fibrosarcomas and carcinogen-induced transplantable fibrosarcomas. Significantly, TGCA was also found in most activated fibroblasts in the skin of chickens with hereditary scleroderma. These results indicate that increased expression of highly branched N-linked oligosaccharides terminating in GlcNAc residues is characteristic of both neoplastic and sclerodermal chicken fibroblasts. Investigation of this phenomenon may thus provide insight into biochemical pathways involved in neoplastic transformation and pathogenesis of a number of non-neoplastic proliferative connective tissue disorders such as scleroderma. Moreover, changes in the expression of TGCA-positive oligosaccharides (or their modified biochemical counterparts in mammalian species) may have considerable value for diagnosis of several connective tissue diseases.

Acetylglucosamine↗
PubMed1989

Immunohistochemical study of ontogeny and phylogeny of a terminal N-acetylglucosamine cluster antigen.

In this work an immunohistochemical method was used to study the ontogeny and phylogeny of a terminal N-acetylglucosamine (GlcNAc) cluster antigen which is an epitope(s) of highly branched N-linked oligosaccharides terminating in GlcNAc residues. The ontogenic studies demonstrated that expression of the antigen is developmentally regulated in lymphocytes, epithelial cells of endodermal origin and kidney mesangial cells of the chicken. The antigen was found in several other avian species studied, namely, the Japanese quail, duck, goose and turkey. Furthermore, the distribution of the antigen in all these species was similar. In adult animals, it was found in bursal and thymic lymphocytes, macrophages, spleen reticulum cells, epithelial cells of the intestine and bronchioles and capillary endothelial cells. The antigen was also detected in epithelial cells of the gastrointestinal tract of several lower vertebrates studied: the amphibian (frog), reptile (chameleon) and fish (rainbow trout). It was undetectable in various organs of the human, African green monkey, calf, pig, rat and guinea-pig, but was found in the intestinal epithelial cells of ten mouse strains. It is likely that biosynthetic processing leading to the formation of highly branched N-linked glycans terminating in GlcNAc residues is conserved during evolution in birds and other lower vertebrates.

Acetylglucosamine↗
PubMed1988

Chicken mucin-cross-reactive antigen.

We have previously described a chicken heterophile antigenic determinant (CHAD-1) shared by Mycobacterium smegmatis and chicken tissues. We then demonstrated that CHAD-1 is present on several chicken glycoproteins and that its immunoreactive domains are highly branched asparagine-linked oligosaccharides terminating in N-acetylglucosamine residues. In the present study, we have shown that CHAD-1 is also expressed by mucin purified to homogeneity from a soluble mucus of chicken intestine. Another antigen found on chicken mucin is a chicken mucin-cross-reactive antigen (CMCRA). Antisera to this antigen were produced by immunization of rabbits with an enriched preparation of CHAD-1 isolated from the bursa of Fabricius. These antisera were absorbed with Mycobacterium smegmatis (to block the anti-CHAD-1 antibody) and with chicken serum, and then used for immunoperoxidase staining of chicken tissue sections for CMCRA. The latter antigen was detected in most medullary cells of the bursa, in epithelial cells and Hassal's corpuscles of the thymus, and in mucus-producing cells of the intestine, esophagus, trachea, and bronchi. Using Western immunoblot analysis, we demonstrated that CMCRA is expressed by a number of polypeptides extracted from bursal lymphoid cells. These polypeptides could not be detected in extracts of thymus, spleen, peripheral blood or bone marrow mononuclear cells.

Animals↗
PubMed1988

Immunochemistry of highly branched N-glycans. Terminal N-acetyl-D-glucosamine (GlcNAc) cluster antigens contain epitopes composed of terminal GlcNAc residues linked to mannose.

We have previously demonstrated by the immunoperoxidase method the presence of a chicken heterophile antigenic determinant (CHAD-1) in medullary lymphocytes of the bursa of Fabricius and thymus as well as in some nonlymphoid cells. It has been found that the anti-CHAD-1 antibody could be neutralized by absorption with several glycoproteins or glycopeptides containing highly branched, asparagine-linked oligosaccharides terminating in N-acetylglucosamine residues. In the present study, fetuin, desialo-fetuin, and a series of 27 highly purified oligosaccharides with well-defined structures were used to investigate the chemical composition and fine structure of the CHAD-1 epitope. It was shown that anti-CHAD-1 antibody binds to oligosaccharides with at least three terminal N-acetyl glucosamine residues at the nonreducing end. These residues may be linked beta 1-2, beta 1-4, or beta 1-6 to one, two, or three different mannose residues. The antibody combining site accommodates at least four carbohydrate residues. Oligosaccharides containing five or six terminal N-acetylglucosamine residues at the nonreducing end demonstrated the highest immunoreactivity with the anti-CHAD-1 antibody. Substitution of terminal N-acetylglucosamine residues with galactose, or with galactose and sialic acid, masks CHAD-1. On the basis of this work, epitopes that react with the anti-CHAD-1 antibody will be renamed terminal N-acetylglucosamine cluster antigens (TGCA). Anti-TGCA antibody has potential use in the monitoring of biosynthetic processing of asparagine-linked oligosaccharides and in studies of their cellular distribution and functions.

Acetylglucosamine↗
PubMed1987

Identification of terminal N-acetylglucosamine residues of highly branched asparagine-linked oligosaccharides as immunoreactive domains of a chicken heterophile antigenic determinant.

Chicken heterophile antigenic determinant (CHAD-1) has been previously found in medullary lymphocytes of the bursa and thymus as well as in some non-lymphoid cells by the immunoperoxidase method, using rabbit antiserum to a complete Freund's adjuvant (CFA) as the first antibody. In this work we demonstrated that absorption of anti-CFA serum with highly purified preparations of hen egg white glycoproteins (ovomucoid, ovoinhibitor, ovalbumin) or chicken orosomucoid completely blocked immunoperoxidase staining for CHAD-1. Treatment of these glycoproteins with beta-N-acetylglucosaminidase suppressed their capacity to inhibit this staining. Absorption of anti-CFA serum with asparagine-linked glycopeptides which have the mannose alpha 1,3 arm disubstituted by GlcNAc residues and which have another GlcNAc residue linked beta 1,4 to the beta-linked mannose of the core also inhibited staining for CHAD-1. These data indicated that highly branched asparagine-linked oligosaccharides with terminal GlcNAc residues beta-linked to mannose represent immunoreactive domains of CHAD-1.

Absorption↗
PubMed1986

Novel heterophile chicken antigen: immunohistochemical localization using antisera to Mycobacterium smegmatis and possible association with lymphocyte maturation.

A novel heterophile antigen shared by Mycobacterium smegmatis and chicken tissues was demonstrated by the indirect immunoperoxidase method using antisera raised in rabbits immunized with a complete Freund's adjuvant containing killed Mycobacterium smegmatis as an immunostimulating component. This antigen was strongly expressed in medullary lymphocytes of the thymus and bursa of Fabricius, but was undetectable in lymphoid cells of the cortical regions of these organs. Only a few lymphocytes stained positively for the antigen in T- and B-cell areas of the spleen. These data suggest that the heterophile antigen is associated with the intrathymic and intrabursal maturation of chicken lymphocytes. The antigen was also detected in some nonlymphoid cells. It was not found in sheep erythrocytes, human and rat tissues or in killed bacillus Calmette--Guerin.

Animals↗
PubMed1979

Radioimmunoassay for human thymus-leukemia-associated antigen.

A competitive radioimmunoprecipitation method was developed for the quantitation of human thymus-leukemia-associated antigen (HThy-L) isolated from human thymus tissue. Antisera to the antigen were raised by immunization of rabbits with purified fractions of HThy-L. The antigen was labeled with 125l by means of a modification of the lactoperoxidase technique and subjected to Sephadex G-100 gel filtration. Analysis of fractions eluted from this column by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed two labeled components with apparent molecular weights of 45,000 and 25,000 daltons, respectively. Immunoprecipitation with anti-HThy-L antiserum demonstrated directly that the 45,000-dalton component carried HThy-L antigenicity. This fraction served as the source of labeled antigen in a competitive radioimmunoassay that permitted the detection of approximately 1 ng HThy-L. With the use of this assay, we confirmed quantitatively that the highest amounts of HThy-L were found in extracts of thymocytes, normal thymus tissues, and lymphoblasts for T-cell lines.

Animals↗
PubMed1979

Quantitation of human thymus-leukemia-associated antigen in established hematopoietic cell lines by radioimmunoassay.

A competitive radioimmunoassay for a saline-soluble human thymus-leukemia-associated antigen (HThy-L) was applied for quantitation of this antigen in leukemia and normal hematopoietic cell lines. Highly increased quantities of HThy-L were detected in all T-cell leukemia lines tested, regardless of the presence or absence of receptors for sheep erythrocytes. This elevated level of HThy-L in combination with high terminal deoxynucleotidyl transferase and adenosine deaminase activities and the presence of a T-lymphocyte-specific surface antigen appear to represent stable phenotypic characteristics of T-cell lines. Most normal B-cell lines had low quantities of HTy-L. The level of HThy-L was slightly elevated in a considerable number of lymphoma B-cell lines and in all non-T, non-B leukemia cell lines tested. No relationship existed between quantities of HThy-L and an expression of different surface immunoglobulin isotypes in B-cell lines. Low quantities of HThy-L were detected in leukemia myeloid and myeloma cell lines as well as in B-cell leukemia lines originating from patients with B-cells acute lymphoblastic leukemia. Apparently, the increased quantities of HThy-L in T-cell leukemia lines may be related to certain stages of T-cell differentiation at which leukemia cell transformation occurs.

Antigens, Neoplasm↗
PubMed1979

Quantitation of human thymus/leukemia-associated antigen by radioimmunoassay in different forms of leukemia.

Using a radioimmunoassay, increased levels of a human thymus/leukemia-associated antigen (HThy-L) have been detected in leukemic cells and plasma from most patients with E-rosette-positive acute lymphoblastic leukemia (ALL) and a number of patients with E-rosette-negative ALL, acute myeloblastic leukemia (AML), acute monomyelocytic leukemia (AMML), and acute undifferentiated leukemia (AVL). Low levels of HThy-L have been demonstrated in white cells from patients with chronic myelocytic leukemia (stable phase) and in mononuclear cells from patients with chronic lymphatic leukemia. The relationship between HThy-L and differentiation of hematopoietic cells is discussed.

Acute Disease↗
PubMed1978

Human thymus-leukemia-associated antigen: isolation and partial characterization.

Human thymus-leukemia-associated antigen (HThy-L), a saline-soluble antigen, was previously detected by immunodiffusion (but not on the cell surface) in significant quantity in extracts of normal thymocytes, cells from cultured T-cell lines, and erythrocyte-rosette-positive leukemia blasts. Two species of HThy-L were identified and isolated from normal human thymus tissue after extraction in tris buffer, ammonium sulfate fractionation, acid precipitation of inactive fractions, DEAE-cellulose (DE-52) chromatography, Sephadex G-100 gel filtration, and carboxymethyl-cellulose (CM-52) chromatography; On Sephadex G-100, both HThy-L species had a similar molecular weight (40,000--50,000), but they eluted in different positions on DE-52 and CM-52. Analysis by sodium dodecyl sulfate polyacrylamide gel electrophoresis showed that each of the 2 HThy-L species contained 2 components with molecular weights of approximately 43,000 and 23,000. Further purification of HThy-L on Sephadex G-50 showed that the 43,000-dalton component possessed HThy-L activity.

Antibodies, Neoplasm↗
PubMed1976

Human thymus/leukemia-associated antigen in normal and leukemic cells.

A saline extractable human thymus/leukemia-associated antigen (HThy-L) has been detected in immunodiffusion using rabbit antisera raised to human thymus extracts. HThy-L was demonstrated in extracts of normal thymocytes, lymphocytes from E-rosetting T-cell lines and from the blast cells of patients with E-rosetting acute lymphoblastic leukemia. Extracts of leukemic cells from patients with acute myeloblastic leukemia and E-rosette-negative acute lymphoblastic leukemia contained significantly lower quantities of HThy-L. Only trace amounts of the antigen were detected in normal spleen tonsil, peripheral blood, bone marrow and PHA-induced lymphoblasts. HThy-L appears to be an antigen associated with the intrathymic differentiation of human T cells and a marker of leukemic cells in certain forms of acute leukemia.

Antigens, Neoplasm↗
PubMed1976

Leukaemia-associated antigen in serum of patients with acute lymphoblastic leukaemia.

A antigen (HThy-L) previously found in extracts of human thymocytes and leukalphaemic cells was detected in sera from four patients with E-rosette-positive untreated acute lymphoblastic leukalphaemia (A.L.L.) and one patient with previously treated acute myelogenous leukaemia (A.M.L.) The disappearance HYth-L angignaplhaemia with treatment was coindent with a decrease in the number of leukaemic blast cells in the peripheral blood. HThy-L antigen was not detected in the sera of the remaining twenty-one patients with E-rosette-negative A.L.L. and seven patients with A.M.L..

Adolescent↗