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Biomedical subjects

N Tanigaki

Publications and source records attributed to N Tanigaki.

At least 19 recordsLinked to original sources

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

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

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

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

Human cell membrane components bound to beta2-microglobulin in T cell-type cell lines.

Cell membrane components bound to beta2-microglobulin were isolated from Renex 30 (a nonionic detergent)-solubilized membrane materials of two human T cell-type cell lines, MOLT-4 and CCRF-CEM, by gel filtration and lectin affinity chromatography. The isolation was carried out by following the beta2-microglobulin activity by radioimmune inhibition assay. The T cell membrane components bound to beta2-microblogulin had a uniform molecular size of about 200,000 daltons and most of them showed an affinity to lentil lectin. The isolated membrane components were radioiodinated and examined for identity to HLA antigens by sequential precipitation with rabbit anti-HLA antiserum (specific to HLA large components) and with rabbit anti-beta2-microblogulin antiserum. In addition to HLA antigens, the beta2-microglobulin-bound components obtained from the MOLT-4 cells were found to contain certain membrane components that are the same in molecular size as the HLA large components but that are different antigenically from the HLA large components. On the other hand, the beta2-microglobulin-bound membrane components obtained from the CCRF-CEM cells were all HLA antigens. No other membrane components were involved in the binding.

Cell Line

Common antigenic structures of HLA antigens. VII. Selective combination binding of beta2-microglobulin with HLA large component in cultured human cell lines.

The intracellular distribution of human beta2-microglobulin was examined in human cell lines (a Burkitt lymphoma cell line, a B-lymphoid cell line and an epighelial-like cell line). Freshly harvested cells were mechanically disrupted and separated into the nuclear, cell-membrane and cell-sap fractions. Nearly 90 per cent of the total beta2-microglobulin was recovered in the cell-membrane and cell-sap fractions. The cell-membrane fraction contained 75-88 per cent of the beta2-microglobulin recovered. The rest was in the cell-sap fraction. Most, 84-91 per cent, of the beta2-microglobulin in the cell-membrane fraction was present combined with membrane fraction was present combined with membrane components of about 38,000 daltons that carried the xenoantigenic activity characteristic of the HLA large component. These membrane components did carry HLA alloantigenic activity. No other membrane components were involved in binding beta2-microglobulin. The beta2-microglobulin in the cell-sap fraction was present in the unbound state. Thus, in the cell lines examined, the membrane component which was combined with beta2-microglobulin appeared to be exclusively the HLA large component and no larg excess of beta2-microglobulin over the HLA large component was found.

Beta-Globulins

A cross-reaction between beta2-microglobulin and kappa-light chains.

Certain antisera to immunoglobulins containing kappa-chains show the presence of antibodies that cross-react with beta2-microglobulin. This was most apparent with an antiserum made to highly purified F(ab) fragments of Fr II gamma-globulin. These cross-reactive antibodies caused positive fluorescence and cytotoxicity reactions with a variety of cell types including T cells. These reactions were completely removed by absorption with highly purified kappa-chains but not with lambda-chains or lambda immunoglobulins. beta2-microglobulin preparations also absorbed or inhibited the special cellular reactivities. Evidence was obtained that HLA-bound beta2-microglobulin was more efficient in this respect. The possibility is discussed that similar cross-reactive antibodies may have been involved in some previous studies of inhibition of T cell function by immunoglobulin antisera.

Absorption

Comparative chemical analyses of the alloantigenic fragments of HL-A antigens.

Papain-solubilized HL-A antigens have been shown to contain two polypeptide fragments: beta2-micro-globulin with a molecular weight of approximately 12,000 and a larger fragment with a molecular weight of about 34,000. The large fragments isolated from two HL-A preparations carrying different specificities appeared homogeneous both by immunoelectrophoresis and sodium dodecyl sulfate-acrylamide electrophoresis. Both HL-A antigen preparations contained the same NH2-terminal (glycine) and the same COOH-terminal residue (serine). The carbohydrate content of the large fragment was 12.9%, making the carbohydrate-free molecular weight approximately 30,000. Small but significant differences have been found in the amino acid compositions and tryptic peptide maps of the two large fragments containing different specificities.

Amino Acids

Absence of a serologically detectable association of murine beta2-microglobulin with the embryonic F9 antigen.

The association of murine beta2-microglobulin to the early embryonic F9 antigen has been investigated by indirect immunofluorescence and by radioimmunoassay. Although some cell lines carry both types of molecules, the beta2-microglobulin was not found expressed on primitive teratocarcinoma cells, where F9 antigen was primarily detected. It is concluded that the low m.w. (12,000 daltons) subunit that was reported to be associated to the F9 antigen is not the adult beta2-microglobulin.

Animals

The component fragments obtained by acid dissociation of papain-solubilized H-2 molecules.

H-2Kk and H-2Dd molecules were specificially purified from a radioiodinated H-2a preparation obtained by papain digestion of spleen cell membranes of A/J strain mice. The molecules were isolated by binding to H-2 alloantisera of the corresponding private specificity followed by precipitation with rabbit anti-mouse IgG antiserum. The specifically precipitated radioiodinated H-2Kk and H-2Dd molecules were dissociated by acid treatment into large and small components of about 37,000 and 11,000 respectively. These were separated by gel filtration at acid pH or by gel isoelectric focusing in the presence of 6 M urea. Each component separated by gel filtration of the acid-dissociated H-2 molecules showed a high degree of size homogeneity as determined by sodium dodecyl sulphate-acrylamide gel electrophoresis. Upon gel isoelectric focusing, however, the small components showed two peaks of radioactivity closely located together at pH 7-8, both of which had a restricted pH range, while the large components gave one peak of a relatively wide pH range of pH 5-6. The H-2Kk and H-2Dd molecules gave essentially the same pattern in terms of the numbers and the positions of the radioactivity bands. Under the iodination conditions used the large components of H-2Kk molecules contained more radioactivity than the small components, while the reverse was true in case of H-2Dd molecules. Such a difference was also found with H-2Kk and H-2Dd molecules isolated by use of alloantisera of the respective public specificity. The assay of binding of the isolated components with H-2 alloantisera of defined specificity revealed that the large components retain most of the allospecificities of the parental H-2 molecules. No H-2 allospecificities were found on the small components. The small components showed extensive binding with rabbit antiserum against mouse beta2-microglobulin. The same antiserum did not show any binding with the large components. On the other hand, both of the components did bind with rabbit antiserum against papain-solubilized H-2 molecules.

Animals

Chromosomal assignment of the HL-A common antigenic determinants in man-mouse somatic cell hybrids.

In the study presented here, man-mouse somatic cell hybrid clones were examined by means of radioimmunoassays for the presence of both beta2-microglobulin (beta2m) and the HL-A xenoantigenic determinant. In addition, the clones were examined for their karyotype and the expression of enzymes with known chromosomal assignments. The results obtained indicate that the gene coding for the HL-A xenoantigenic determinant is carred on chromosome 6. The data obtained provides a direct demonstration that the gene coding for beta2m segregates independently of that coding for the alloantigenic polypeptide chain of the HL-A molecule, and that the gene coding for beta2m is carried on chromosome 15.

Animals