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N Tanigaki

Publications and source records attributed to N Tanigaki.

At least 73 records · Page 4Linked to original sources
PubMed1982

A human thy-1-like antigen expressed on cultured leukemic T-cells.

A human cell membrane antigen that is highly T-cell specific among a number of leukocyte cell lines was isolated from cells of a human T-cell leukemia cell line, SKW-3. In addition to the high specificity to T-cell-type cell lines, the isolated antigen showed the following characteristics: (1) It is an acidic glycoprotein of approximately 30 000 daltons that has a charge heterogeneity and probably a disulfide bond(s); (2) Its antigenicity is stable when treated with heat, acid, and various protein denaturants; (3) It is widely distributed in lymphoid and nonlymphoid tissues but is most predominant in brain. These features are similar, if not identical, to those reported for the Thy-1 antigen of mouse or rat and have raised the possibility that this cell membrane antigen may correspond to human "lymphocyte" Thy-1 antigen, the counterpart of human "brain" Thy-1 antigen.

Antigens, Neoplasm↗
PubMed1982

Assessment of the specificity of human Ia alloantisera and alloantigens by the use of radioiodinated human Ia antigens.

A method for preparing radiolabelled human Ia antigens and a utilization of the labelled antigens in defining the Ia specificity of antigens and antisera are presented. The standard preparation procedure involves solubilization with Renex 30 (a non-ionic detergent), purification by gel filtration and lectin-affinity chromatography, and radioiodination, and yields an Ia preparation with immunological purity of 48-62%. The basic procedure for defining the Ia specificity of antisera is a direct binding assay: it allows to react a given antiserum with a panel of labelled Ia preparations of different specificities and measures the extent of binding by the double antibody technique. The major or putatitve specificity can be deduced from the reaction pattern. The specificity can be further evaluated by a sequential binding test or a binding inhibition test. The Ia tissue typing is performed by the binding inhibition assay: it measures the ability of test tissues to inhibit the binding of a reference labelled Ia preparation with a reference Ia antiserum. This assay permits Ia typing with unseparated blood leukocytes of 2 to 3 x 10(5). These radioimmunoassay procedures can offer a solution to problems involved in human Ia serology.

Antibody Specificity↗
PubMed1982

A new Epstein-Barr virus negative Burkitt's lymphoma derived cell-line. I. Analysis of cell surface markers and abnormal expression of HLA antigens.

CHEV, a new Epstein-Barr virus negative Burkitt's lymphoma derived cell line has been studied. Karyotype analyses demonstrated the t (8; 14) characteristic translocation. Cell surface characterisation of this line showed the presence of mu and chi immunoglobulin chains and beta 2-microglobulin and the absence of the complement receptor. We are unable to detect HLA--A, B alloantigens on the cell surface which was in contrast with an apparently normal expression of these antigens in the cytoplasm.

Antigens, Neoplasm↗
PubMed1981

Binding of one monoclonal antibody to human Ia molecules can be enhanced by a second monoclonal antibody.

A monoclonal anti-human Ia antibody, PTF 29, was tested for its ability to bind purified, 125I-labeled human Ia preparations. It was found that the binding level increases considerably in the presence of a second monoclonal antibody. Experimental conditions were selected under which only the binding of PTF 29 and not the binding of the second antibody could be determined. Under these conditions, it was found that "helped" PTF 29 binding has higher affinity and is exerted on a molecular subset different from that bound by PTF 29 alone. This phenomenon, while not easily accommodated in the present conceptual framework of the human Ia system, appears in itself interesting and may have more general implications.

Animals↗
PubMed1981

Separation and comparison of human TL-like antigens and HLA(A, B, C) antigens expressed on cultured T cells.

Beta 2-microglobulin-bound T-cell membrane components containing both human TL-like antigens and HLA(A, B, C) antigens were partially purified from Renex 30-solubilized membrane material of cells of a human T-cell-type leukemia cell line, HPB-ALL. The radioiodinated preparation was subjected to limited papain digestion; the HLA(A, B, C) antigens split, whereas a large portion of the human TL-like antigens remained intact. The antigen molecules were recovered by lentil-lectin affinity chromatography and separated by gel filtration on the basis of the induced difference in molecular size. The human TL-like-antigen preparation thus obtained was essentially free of HLA(A, B, C) antigens. The human TL-like antigens were immunospecifically precipitated and the component polypeptide, heavy and light, chains were separated by acid dissociation followed by gel filtration. The component chains were compared with the corresponding chains of HLA(A, B, C) antigens obtained similarly from the same HPB-ALL cells with respect to their fragmentation patterns on chemical or enzymatic cleavage. The results provided convincing evidence for the identity of the light chains of human TL-like antigens and HLA(A, B, C) antigens, and also evidence suggesting the presence of substantial differences in the fundamental structure of the heavy chains of human TL-like antigens and HLA(A, B, C) antigens.

Animals↗
PubMed1981

Distribution of antigenic determinants recognized by three monoclonal antibodies (Q2/70, Q5/6 and Q5/13) on human Ia-like alloantigens and on their subunits.

The distribution of antigenic determinants recognized by the anti-Ia-like antigen monoclonal antibodies (MoAb) Q2/70, Q5/6 and Q5/13 on molecules coded for by the DR locus and by non-DR loci was investigated using a binding assay with 125I-labeled Ia-like antigens isolated from four B lymphoid cell lines. The determinants reacting with the MoAb Q2/70 and Q5/13 are expressed on all DR alloantigens tested and on BR4X7 specificities, while those reacting with the MoAb Q5/6 are not detectable on DRw7 and BR4X7 molecules. None of the monoclonal antibodies reacted with DC1 molecules. The MoAb Q5/6 and Q5/13 reacted with the isolated beta subunit of the Ia-like antigenic complex, while the MoAb Q2/70 did not react with the isolated chains.

Animals↗
PubMed1981

Further characterization of two "DR supertypic" specificities. Additional evidence that they reside on molecules different from those carrying HLA-DR locus specificities.

Peripheral lymphocytes from a panel of individuals who had been assayed for DR specificities by the conventional cytotoxicity assay were typed for DR "supertypic" specificities, DC1 and BR4 x 7, by the radioimmunoassay. A positive and a negative population were clearly distinguished for both specificities and the strong association of the DC1 specificity with DR1, 2, and w6 was confirmed as well as the BR4 x 7 specificity with DR4 and 7. Family study also supported this strong association. Appropriate papain digestion separated molecules carrying DC1 determinant from those carrying DR2 as well as from those carrying DRw6, and separated molecules carrying BR4 x 7 from those carrying DR4. Specificity analysis of the 8th Workshop antisera by use of these separated antigen preparations showed that some anti-DC1 antisera do not possess appreciable anti-DR1, 2, or w6 activity and vice versa. The same was found for DR4 x 7 in its relationship with DR4 and 7. The existing evidence could be explained most economically by assuming a genetic model of two loci in linkage disequilibrium each coding for analogous but distinct forms of the small (beta) subunits of Ia molecules.

Epitopes↗
PubMed1981

Immunochemical definition of the new dr specificity 8WDRw13.

Using two alloantisera produced by planned immunization of blood donor volunteers, a new specificity was defined residing on human Ia molecules. The specificity is possessed by the following human lymphoid cell lines: Reh, NALM-1, B89, KM-3 and BJAB, and appears to be the same as the DRw13 specificity discovered in the 8th International Histocompatibility Workshop. A radioimmunoassay for typing w13 on peripheral blood lymphocytes was established. A population and family study supports the genetic control by the HLA-DR locus. The phenotypic frequency in an Italian population was 3.7 percent. The relationship between w13 and the MT2 supertypic specificity was confirmed at the molecular level and the papain sensitivity of w13-carrying molecules was determined.

Cell Line↗
PubMed1980

Molecular identification of human Ia antigens coded for by a gene locus closely linked to HLA-DR locus.

Human Ia(-like) specificities controlled by gene loci other than HLA-DR were searched for at the molecular level in cells of human B-cell-type cell lines which carry two established DR specificities. Chevalier cells of DRw3 and 7 and U698M cells of DRw2 and 4 were used. Their Ia molecules were partially purified, radioiodinated and analyzed for Ia specificities by the direct binding and sequential binding assays with a selected panel of human Ia alloantisera. It was possible in both the cell lines to define a third subset of Ia molecules carrying a new specificity in addition to two Ia subsets carrying the established DR specificities. The new specificity was detected by putative anti-DRw4 and anti-DRw7 antisera and was closely associated with DRw4 and DRw7 at population level. It was thus designated provisionally as BR4X7. These results suggest that the BR4X7 specificity is coded for by a separate Ia locus closely linked to HLA-DR locus. The determinant(s) responsible for BR4X7 was located on the small subunit of Ia molecules.

Animals↗
PubMed1980

HLA-DR typing by radioimmunoassay.

A radioimmunoassay procedure is described by which peripheral blood lymphocytes can be typed for HLA-DR specificities. The major advantages of this method are the following: simple and reproducible procedure, no need for B lymphocyte separation, no need for optimal viability, and no need for preabsorption of antisera with platelets. This method will find an application in the genetic and biochemical analysis of the HLA complex, and in the clinical tests of Ia antigens for diagnostic or prognostic purposes and in retrospective transplant studies.

Antibody Specificity↗
PubMed1980

Purification and separation of subsets of human Ia molecules by papain digestion.

Papain digestion of human Ia(-like) molecules was performed under various conditions using 125I-labelled preparation of non-ionic-detergent-solubilized Ia antigens of Daudi cells. The products were examined for their allospecificities by a direct binding reaction with human Ia alloantisera. The Daudi Ia preparation is known to contain Ia molecules of DRw6 specificity, an HLA-DR specificity and also Ia molecules of DC1 specificity, a putative non-HLA-DR specificity. Limited papain digestion cleaved off the hydrophobic portion of human Ia molecules and gave smaller sized Ia products. The cleavage did not affect the Ia alloantigenic determinants and occurred much more readily with molecules of DC1 specificity than with molecules of DRw6 specificity. As a consequence, limited papain digestion of the Daudi Ia pool yielded an Ia preparation with DRw6 specificity but lacking DC1 specificity and another Ia preparation which was enriched in DC1 specificity. The limited papain digestion of the Daudi Ia pool followed by gel filtration and LcH affinity chromatography also produced Ia REPARATIONS OF HIGH PURITY. Extensive papain digestion damaged the Ia alloantigenic determinants but the DC1 determinant was much more resistant than the DRw6 determinant. Thus extensive papain digestion yielded an Ia preparation which was relatively rich in DC1 specificity and essentially devoid of DRw6 specificity.

Antigen-Antibody Reactions↗
PubMed1979

Human cell membrane components dominant in T cell lineage: identification and characterization of human TL-like antigens.

Cell membrane components that contain beta 2-microglobulin were purified from cells of a human T cell-type leukemia cell line, HPB-ALL. They contained membrane components that have the same molecular size and the same subunit structure as HLA(A,B,C) antigens but are separable from the typical beta 2-microglobulin-containing cell membrane components, i.e., the HLA (A,B,C) antigens, by xenoantibody reagents. A sensitive radioimmunoassay was constructed for detection of the T cell membrane components. The assay revealed that the cell membrane components are expressed exclusively on cells of T cell-type leukemia cell lines among the human lymphoid cell lines tested, predominantly in thymus, among the human organs and tissues tested. They were not present on cells of human B cell-type cell lines or on cells of nonlymphoid organs and tissues. No alloantibodies directed to the T cell membrane components, the putative human homologues of mouse TL antigens, were found in any of the human tissue typing sera tested.

Animals↗
PubMed1979

Human Ia-like antigens in non-lymphoid organs.

Human Ia-like antigens in liver and kidney were shown by the immunofluorescence assay to be present mostly in the endothelial-mesenchymal cells of these organs. The parenchymal cells apparently contained no human Ia-like antigens. The antigens in liver and kidney were purified and shown to have the same subunit structure as human Ia-like antigens of cultured B-lymphoid cells. The human Ia-like antigens in non-lymphoid organs, not only in liver and kidney but also in testis, heart, muscle and brain, carried all the xenoantigenic characteristics of human Ia-like antigens expressed on lymphoid cells of B-cell lineage.

Antigen-Antibody Reactions↗
PubMed1978

Immunological dissection of human Ia molecules.

The immunochemical analysis of Daudi Ia molecules by a variety of alloantisera led to the recognition of at least three molecular species carrying different antigenic determinants: DRw6, DC-1, and DC-2. Genetic as well as structural evidence indicates that DRw6 and DC-1 molecules are controlled by separate, HLA-linked loci, rather than by alleles at the same locus. The alloantigenic determinants appear to be expressed on the small Ia subunit. DC-1 and DC-2 determinants discussed had not been defined by serological analysis at the population level, but were demonstrated to be present by immunochemical analysis at the molecular level.

Antigen-Antibody Reactions↗
PubMed1978

Absence of reaction of a xenogenic anti-H-2 serum with mouse embryonal carcinoma cells.

A rabbit antiserum raised against papain-solubilized H-2 antigens has been used to investigate the eventual expression of H-2 antigens and related molecules on embryonal carcinoma cells and on other types of mouse cells. No material reacting with this serum could be detected on cells carrying the F9 antigen. It is concluded that no H-2 antigen or cross-reacting material is expressed on these cell types.

Animals↗