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D L Mann

Publications and source records attributed to D L Mann.

At least 253 records · Page 14Linked to original sources
PubMed1976

Structure of HLA antigens: amino-acid and carbohydrate compositions and NH2-terminal sequences of four antigen preparations.

Amino-acid and carbohydrate compositions in addition to limited NH2-terminal sequence data of four preparations of HLA antigens, including products of both of the major histocompatibility loci (HLA-A and HLA-B), show that the antigens have great homology in the primary structure. A striking observation is that HLA antigens also have a considerable structure homology with mouse H-2 antigens. HLA antigens appear to have one carbohydrate side chain which has the same composition in all four cases. The possible relation of the structure of the heavy chain of HLA antigens to immunoglobulins is discussed, based on the limited data which are available so far.

Amino Acid Sequence↗
PubMed1976

Specific MLC stimulation by cultured B cells.

Pairs of cultured T and B lymphoid cells, derived from the same individual, were used as stimulating cells in MLC experiments. Blastogenic response to cultured B cells were much greater than those to the corresponding T cell line. These cells will provide a useful reagent for isolation and characterization of B cell specific antigens.

B-Lymphocytes↗
PubMed1976

Temporary inhibition of antibody-dependent, cell-mediated cytotoxicity by pretreatment of human attacking cells with ammonium chloride.

Treatment of lymphoid cell preparations with ammonium chloride buffers to remove contaminating erythroid cells markedly reduced the ability of these cells to function as attacking cells in antibody dependent cell mediated cytotoxicity tests (ADCC). The lymphoid cells, however, retained their ability to adhere to antibody-coated target cells. Recovery of function 20 hr after exposure to ammonium chloride suggests a metabolic rather than receptor effect of these salts on the ADCC function of lymphocytes.

Ammonium Chloride↗
PubMed1976

Lack of association of human "B cell" antigens and Fc receptor activity of antibody-dependent cytotoxic lymphocytes.

Heterologous antisera directed against human B cell antigens were tested for their ability to inhibit the function of Fc receptors on human lymphocytes. These antisera coated on the attacking cells in a lymphocyte-dependent antibody-mediated cytotoxic assay inhibited lysis of sensitized target cells. However, the F(ab)2 fragments of the IgG fraction of an anti-human Ia antiserum failed to inhibit the killing of sensitized targets by attacking cells. Antisera against other lymphocyte membrane antigens also inhibited target cell lysis when coated on attacking cells. These results suggest that there is not identity between human B cell antigens and Fc receptors of antibody-dependent cytotoxic lymphocytes.

Animals↗
PubMed1975

Acute myelocytic leukaemia and leukaemia-associated antigens in sisters.

In a sibship of 5 brothers and 7 sisters, 3 sisters died from acute myelocytic leukaemia while a 4th probably had the same disease. Laboratory studies on the close relatives revealed that a 5th sister had persistently high erythrocyte sedimentation-rates and serum-IgM levels and serological evidence of acute leukaemia-associated antigens. These findings suggest a possible preleukaemic state in this patient.

Acute Disease↗
PubMed1975

Detection of antigens specific for B-lymphoid cultured cell lines with human alloantisera.

Human sera were tested for cytotoxicity to pairs of long-term tissue-cultured cell lines. Each pair had been derived from the same individual and one of the pairs possessed the characteristics of either "T" or "B" cells. The alloantisera used were HL-A-typing reagents or sera obtained from Amish multiparas. Selected cytotoxicity was found against the B-cell lines by direct testing. Cytotoxicity was abolished by absorption with B-cell line but not by absorption with the T-cell lines. The results suggest that a group of allotypic antigens may be expressed exculsively on human B cells.

B-Lymphocytes↗
PubMed1975

Purification of papain-solubilized histocompatibility antigens from a cultured human lymphoblastoid line, RPMI 4265.

HL-A antigens having specificities HL-A2, HL-A7, HL-A12 have been solubilized by papain treatment of membrane preparations from the cultured human lymphoblastoid cell line RPMI 4265 and purified about 80-fold by chromatography on carboxymethylcellulose, Sephadex G-150, and diethylaminoethylcellulose columns. Separation of HL-A2 from a mixture of HL-A7 and HL-A12 was achieved on the final DEAE-cellulose column. The yield was about 1 mg of protein of each antigen preparation per 100 g of packed, frozen cells. On sodium dodecyl sulfate gel electrophoresis both preparations showed two polypeptide bands. The smaller subunit of 12,000 daltons is common to all HL-A preparations and has been shown to be identical with beta2-microglobulin. The larger subunit is a glycopeptide and in the HL-A7, 12 preparation was resolved into a duplex of 34,000 and 37,000 daltons. The HL-A2 preparation showed a single band at 34,000 daltons. On isoelectric focusing under nondenaturing conditions, the preparation showed multiple bands, all of which contained both subunits and retained antigenic activity. On isoelectric focusing in the presence of 6 M urea a single band for beta2-microglobulin and multiple bands for the larger subunit were seen. This charge heterogeneity of the larger subunit has been shown to be due to variable amounts of sialic acid. When HL-A antigen preparations were subjected to Sephadex G-100 chromatography in the presence of 3 M KCl, no separation of the two subunits was observed.

Cell Line↗
PubMed1975

Specific human B lymphocyte alloantigens linked to HL-A.

Sera, previously found to react specifically with B lymphoid cultured cells, were tested on isolated T and B peripheral blood lymphocytes in a microcytotoxicity assay. Studies were performed on lymphocytes obtained from several large Amish families. The sera used in these studies were cytotoxic to peripheral blood, B lymphocytes, but not cytotoxic to T lymphocytes. The antigens detected followed the inheritance pattern of HL-A haplotypes. The strong linkage disequilibrium with HL-A antigens suggests that genes controlling the expression of B lymphocyte antigens are linked to genes controlling HL-A alloantigens.

B-Lymphocytes↗
PubMed1975

Human antisera detecting leukemia-associated antigens on autochthonous tumor cells.

Leukemia patients in remission were immunized with RAJI lymphoid tissue culture cell lines. Four of 7 patients developed antibody to the immunizing cell as well as to allogeneic leukemia cells. Sera from 3 patients were tested against autochthonous tumor cells either frozen or obtained at the time of disease relapse. Patient's sera were cytotoxic to their own leukemia cells; however, this cytotoxicity was lost at the time of relapse.

Antigens, Neoplasm↗
PubMed1975

A clinical trial of chemotherapy and RAJI immunotherapy in advanced acute lymphatic leukemia.

Patients in remission with advanced acute lymphatic leukemia were randomly assigned to receive chemotherapy alone or chemotherapy plus immunotherapy with a Burkitt lymphoma tissue culture cell line (RAJI). Remission duration in both groups were identical. Complement-dependent cytotoxic antibody was seen in 5 of 8 immunized patients and 0 of 8 controls. This antibody reacted with RAJI and both allogeneic and autologous acute leukemia cells. Antibody titers began to rise after 2 months, peaked at 4 months, and then declined prior to relapse in all patients. The time course of the increase in mixed-leukocyte culture response to RAJI was similar to immunized patients. An increased in vitro response to phytohemagglutinin was seen during drug administration in all patients. Although no clinical benefit was seen in this small number of patients with the RAJI injections, these in vitro responses are encouraging and new immunization schedules will be investigated.

Antibodies, Neoplasm↗