PubMed Health⌕ Search

Biomedical subjects

M J Giphart

Publications and source records attributed to M J Giphart.

100 records · Page 6Linked to original sources

The major histocompatibility complex of rhesus monkeys, RhLA: XV. Chemical characterizations of DR locus antigens and antigen 48.

Immunoprecipitation studies of the rhesus monkey major histocompatibility system have shown that the RhLA-DR locus codes for class II antigens with molecular features that are homologous to the class II antigens coded for by the human HLA-DR locus. The product of another alloantigenic RhLA-linked locus of the rhesus monkey, called '48', is provisionally characterized as a class I system.

Animals↗

On the dynamics of HLA-A2 antigen-antibody complexes on the cell membrane of human peripheral blood lymphocytes. A biochemical and electron microscopical autoradiographic study.

This report deals with some dynamic aspects of membrane bound immune complexes of HLA antigens and antibodies. Radiolabelled HLA antibodies were used to sensitize peripheral blood lymphocytes. Upon in vitro incubation of these cells, two different events were detected: 1) Immune complexes and a limited amount of free antibody were shed into the culture supernate; from the immune complexes specific antibodies could be regenerated. 2) Immune complexes were also internalized by means of endocytosis as visualized by electron microscopical autoradiography. Antibodies were found above dense bodies (lysosomes) and above multivesicular bodies. The results are discussed in relation to the biology of membrane bound HLA molecules.

Antigen-Antibody Complex↗

The major histocompatibility complex of rhesus monkeys. VIII. Isolation and partial characterization of SD antigens.

The structure and chemical nature of the serologically defined (SD) antigens coded by the major histocompatibility complex (RhLA) of rhesus monkeys was studied. The use of specific anti-SD sera allowed the selective isolation of the corresponding antigens from crude antigen preparations. These were obtained by detergent solubilization after incorporation of 3H, 35S, and 14C amino acids in lymphocytes or mitogen-stimulated lymphoblasts. The results indicate that the SD antigens are of proteinaceous nature and are composed of two polypeptide chains with molecular weights of 44,000 and 12,000, the latter being beta 2-microglobulin. No differences in molecular size and subunit composition were detected between antigens of both segregant series. The results are discussed in relation to similar data available for the analogous human and murine histocompatibility antigens.

Animals↗

HLA-D associated alloantisera react with molecules similar to Ia antigens.

Two human alloantisera specific to bone marrow-derived lymphocytes (B cells) were shown to precipitate polypeptide chains of 29,000 and 34,000 daltons from human lymphoblastoid B cell lines. These molecules are similar to murine Ia antigens and are also precipitated by a rabbit B-cell specific heteroantiserum. Since the alloantisera are thought to recognize determinants coded by HLA-D or closely linked loci, these data support the hypothesis that these B-cell specific alloantigens are the human counterpart of the mouse Ia antigens and may be the products of HLA-D.

B-Lymphocytes↗

The application of radiolabelled HL-A antibodies in the detection of (soluble) transplantation antigens: an alternative for the microcytotoxicity test.

The use of radiolabelled anti HL-A antibody preparations is described. Absorption by platelets, followed by acid elution, fractionation of the eluate by column chromatography, radiolabelling and a second absorption--elution step with platelets yielded specific preparations, irrespective of original cytotoxic titres. The binding of these radiolabelled antibodies to lymphocytes could be inhibited by soluble antigens present in normal plasma or obtained from spleen cells by papain treatment. As a method for the detection of soluble transplantation antigens the use of radiolabelled antibodies appeared as sensitive as the microcytotoxicity test.

Adsorption↗

The Eurotransplant HLA-DRB oligonucleotide typing set.

Several sequence-specific oligonucleotides (SSO) were designed based upon available sequences of HLA-DRB1 genes which are associated with HLA-DR serotypes. Targets for these SSO were polymerase chain reaction (PCR) products using primers specific for the second exon of DRB genes. In view of practically, a hybridization system was developed which was independent of temperature or composition of the hybridization buffers, hence uniformly applicable to all SSO, yet allowing discrimination based upon one nucleotide mismatch only. The SSO typing results were compared with HLA serological typing and a high correlation was observed (99%).

Alleles↗