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H A Vaughan

Publications and source records attributed to H A Vaughan.

31 records · Page 2Linked to original sources
PubMed1991

The isolation of cDNA clones for CD48.

HuLy-m3 is an Mr 47,000 pan-leukocyte antigen detected by the monoclonal antibody (mAb) 5-4.8. This report describes the isolation and analysis of a cDNA clone encoding HuLy-m3. Serological analysis demonstrated that antibodies of the CD48 cluster also reacted with transfected cells expressing HuLy-m3. The DNA sequence of the clone suggests linkage to the cell membrane through a glycosyl phosphatidylinositol tail and this was verified experimentally. Sequence similarity with the human B-cell activation antigen Blast-1 was noted.

Amino Acid Sequence↗
PubMed1988

Immunoradiometric assay for the rapid detection of HLA-B27.

A new method for the rapid detection of the HLA-B27 antigen is discussed which consists of a direct immunoradiometric assay (IRA) utilizing a 125I-labelled, HLA-B27 specific monoclonal antibody to detect HLA-B27 in whole citrated blood. Thus far, the assay has been used to assign HLA-B27 status in a population study involving 142 individuals; 36 subjects were HLA-B27+ by conventional microcytotoxicity and all 36 were detected by the new IRA and all 106 B27- individuals were also accurately assigned by IRA. The problem of detection of the cross-reactive HLA antigen HLA-B7 was overcome by blocking the reactive sites on HLA-B7 molecules with the HLA-B7 specific antibody, BB7.1. This new assay enables accurate detection of HLA-B27 within 30 min of venepuncture and should facilitate the assessment of HLA-B27 status in tissue typing laboratories.

Antibodies, Monoclonal↗
PubMed1988

HLA (class I) antigens on platelets are involved in platelet function.

HLA (Class I) antigens are ubiquitous in their cellular distribution and, while their function in major histocompatibility complex (MHC)-restricted phenomena are clear, their function on other cells, such as platelets, is not so obvious. We now report that several anti-HLA monoclonal antibodies (including an anti-beta 2 microglobulin antibody) selectively affect platelet function in that three different anti-HLA monoclonal antibodies caused not only the aggregation of human platelets, but also caused the release of 14C-serotonin. In addition, the anti-HLA antibodies could selectively block the binding of several platelet agonists such as collagen, adrenalin, ADP, but not the binding of others such as thrombin and arachidonic acid. In blocking studies there also appeared to be an association between platelet glycoprotein IIb-IIIa and HLA Class I antigens. We propose that both heavy and light chains of Class I HLA antigens on platelets may be involved in platelet aggregation and release and suggest an additional role for HLA antigens on platelets.

Antibodies, Monoclonal↗
PubMed1987

Isolation of the CD7 gene from the DNA of transfected L cells.

Using DNA from L cells which expressed high levels of the CD7 (Leu-9 or HuLy-m2) antigen obtained after two cycles of transfection, a genomic library was constructed in the lambda phage Charon 4A. Recombinant clones containing the gene coding for this antigen were identified by first screening the library with both the HSV-tk gene and a probe detecting the human repetitive (Alu) sequences. DNA from 10 tk+ and 12 Alu+ recombinant clones was used to transfect L cells which were analyzed for the cell-surface expression of CD7 either early (48-72 h posttransfection) or later when hypoxanthine aminopterin thymidine-resistant colonies were obtained. Transfection with either Alu+ or tk+ recombinant phages led to transient early expression of CD7, and stable CD7+ transfectants were also established. Thus the CD7 gene has been isolated in a number of clones in association with either the Alu repetitive sequence or with the HSV-tk gene; the insert size in one of the genomic clones was 13.5 kb.

Animals↗
PubMed1986

Human class II antigens. Implication of carbohydrate in the determinants recognized by several antihuman class II monoclonal antibodies.

Several monoclonal antibodies (McAbs) to human class II antigens are described; three of these recognize monomorphic epitopes, and two are polymorphic. The biochemical nature of the reactive epitopes was investigated by determining the binding ability of the McAbs to protease- or glycosidase-treated antigen preparations. Both of the polymorphic McAbs recognized protein-defined epitopes. However, for one of the antibodies F5C9, carbohydrate residues were also implicated. The extent of carbohydrate involvement varied with class II antigens of different DR specificity, suggesting that the proximity of the F5C9 epitope to carbohydrate side chains can vary. One of the three monomorphic McAbs recognized a protein-defined epitope, while the other two antibodies detected epitopes in which carbohydrates were involved. These results indicate that both protein and carbohydrate residues of the human class II antigens can influence the epitopes recognized by murine McAbs. This could explain some of the apparent complexities of the anti-human class II McAbs.

Antibodies, Monoclonal↗
PubMed1983

Description of a mouse monoclonal anti-HLA-B27 antibody HLA-ABC-m3.

The production and characterization of a new anti-HLA-B27 monoclonal antibody HLA-ABC-m3 is described. This cytotoxic IgG2a antibody binds protein A and is able to precipitate cell surface molecules of 43,000 and 12,000 daltons corresponding to the HLA heavy chain and beta 2-microglobulin. Population testing revealed that the HLA-ABC-m3 antibody reacted with the peripheral blood lymphocytes of 47/47 individuals conventionally typed as HLA-B27+ and with 5/105 HLA-B27- individuals. These five extra reactions were with individuals expressing the cross-reactive HLA-B7 alloantigen, although the affinity of the monoclonal antibody for B27 heterozygous individuals (approx 10(9) M-1) was tenfold greater than with B7 individuals (approx 10(8) M-1). In addition, HLA-ABC-m3 reactivity segregated with HLA-B27 in two families. This monoclonal antibody should be of value in the investigation of the role of HLA-B27 in disease.

Animals↗
PubMed1983

The definition of an MB related specificity by a monoclonal antibody.

A number of monoclonal antibodies have been described that react with monomorphic and polymorphic Ia-like specificities on human B cells, but it is not clear whether these react with HLA-DR encoded molecules or with the products of other closely linked genes within the MHC, such as MB, MT, or DC 1 antigens. A monoclonal antibody is described herein (MC-26.1) which detects a new Ia-like specificity as shown by B-cell reactivity, chemistry, family studies, including recombinant family and coprecipitation studies. The latter studies showed that specificity detected by the MC-26.1 antibody coprecipitated with determinants detected by conventional anti-MB3 and MT3, but not with HLA-DR4 antisera. The determinant was polymorphic but not related to any of the known MB or MT specificities. However, cross-reactions were demonstrated by the variability of reaction on different individuals. Coprecipitation studies indicate that the antigen defined by MC-26.1 coprecipitates with MB and MT specificities suggesting that the antibody defines a new specificity on the MB3 and MT3 molecules.

Animals↗
PubMed1983

Hu Ly-M3--a human leukocyte antigen.

A monoclonal antibody, 5-4.8, was produced against human peripheral blood lymphocytes and it appears to be leukocyte-specific in that it reacts with a common determinant (called Hu Ly-m3) present on the peripheral blood T, B and null lymphocytes of 40 individuals. The antibody also reacts with thymocytes, spleen cells, and bone marrow cells (30%) and weakly with granulocytes and platelets--but not with heart, liver, or kidney. Affinity to lentil-lectin and molecular weight analysis demonstrated that Hu Ly-m3 is a glycoprotein consisting of a single chain of 47,000 daltons which is not HLA because it is not present on all cells; because it is present on the surface of the phenotypically HLA- Daudi cell line; and because soluble HLA antigens did not inhibit the binding of the 5-4.8 antibody.

Animals↗
PubMed1981

Cross-reactions of Ia antigens between mouse and man.

Murine alloantisera with specificity for the I-region of the MHC were found to cross-react with human B lymphocytes. By using antisera selected for subregion specificity and including monoclonal antibodies, antisera directed to I-E/Ck products were shown to have the greatest cross-reactivity with human cells. In the reciprocal direction, human anti-DRw alloantisera were also found to contain antibodies that reacted with murine B lymphocytes, and by using congenic strains this reaction was shown to be MHC restricted and was of the "Ia type." By studying appropriate intra-H-2 recombinant strains. The reactivity could be mapped to the 1-E subregion (especially to 1-Ek). In addition, antibodies to the murine 1-Ek subregion could specifically block the reaction of the two DRw antisera examined; whereas, anti-I-Ak antisera were without effect. These studies further highlight the unique cross-reactions between two highly polymorphic gene produces in mouse and man, and demonstrate that the 1-E subregion in the mouse codes for the most cross-reactive specificities.

Animals↗
PubMed1981

Serum Ia levels during tumor growth in mice and humans.

Antigen stimulation in mice such as occurs with the rejection of an allogeneic tumor graft caused a substantial rise in serum glycolipid Ia levels. However, mice bearing a measurable syngeneic tumor had no detectable Ia antigens in their sera; this observation was made in several different strains of inbred mice with 5 different tumors. In each instance the serum Ia level fell as the tumor grew progressively, reached zero at about the time the tumor was visible, and remained at this zero level until the mouse died. Similar results were found in humans: Tumor-bearing patients had markedly suppressed serum Ia levels. The mechanism of the fall in serum Ia glycolipid levels is not known, but the measurement of the serum Ia glycolipid content appears to reflect the level of activation of the immune system, and the suppression of serum glycolipid Ia levels found in tumor-bearing mice and patients may have important clinical implications.

Animals↗