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Biomedical subjects

S Ferrone

Publications and source records attributed to S Ferrone.

At least 433 records · Page 24Linked to original sources

Establishment of paired tumor cells and autologous virus-transformed cell lines to define humoral immune responses in melanoma and sarcoma patients.

Peripheral blood lymphocytes and skin fibroblasts from 12 cancer patients were infected with Epstein-Barr virus (EBV) or SV40 virus. The EBV-transformed lymphoblasts and SV40-transformed fibroblasts were grown as continuous cell lines and expressed the same histocompatibility antigens as tumor cell lines established from the same cancer patients. Sera from 350 melanoma and 195 sarcoma patients were tested for antibody reactive with membrane antigens on three of these tumor cell lines (two melanomas and one sarcoma) by immune adherence (IA) and indirect immunofluorescence (IMI) assays. Antibodies to HLA and other non-tumor-related antigens were completely removed from the most reactive sera by quantitative absorption with 4 x 10(7) lymphoblasts or 10(7) transformed fibroblasts autologous to the tumor target cells. These paired cell lines were used to monitor humoral immune responses in melanoma and sarcoma patients receiving allogeneic tumor cell vaccines.

Antibodies, Neoplasm↗

Human lymphoid cell lines as targets for DRw.

Cultured human lymphoid cell lines (LCL) are useful as a source of target cells in several immunologic assays. More recently such cells have been used for the serological characterizations of the HLA-DR antigens. Typing of the same LCL in various laboratories during the VII Histocompatibility Workshop has given comparable results with a discordancy rate of less than 10%. This discordancy is likely to reflect the different sources of complement that can greatly alter the results of cytotoxic assays. The presence of naturally occurring antibody in rabbit complement to human cells can be avoided by: (a) absorbing with human cells at 0 degrees C; (b) dilution with human serum; (c) dilution with heat-inactivated rabbit serum; (d) repeated freeze-thawing of the complement; or (e) careful selection of complement by screening procedures. Comparison of the results of HLA-DR typing of LCL with peripheral B-cells of the same donor show good correlations. However, LCL will occasionally give extra reactions perhaps due to the expression of new antigens. LCL can be coated with F(ab')2 fragments from antihuman beta2-microglobulin antibodies that block reactions of HLA-A, -B and -C antibodies allowing for discrimination of anti-DRw activity.

B-Lymphocytes↗

Murine Ia and human DR antigens: homology of amino-terminal sequences.

Murine Ia and human DR antigens were isolated and purified by immunoprecipitation and sodium dodecyl sulfate/polyacrylamide gel electrophoresis with allo- and xenoantisera, respectively. The I-A subregion antigen consists of two chains, designated Aalpha and Abeta, with molecular weights of 35,000 and 26,000, respectively. The I-C subregion antigen likewise consists of two chains, designated Calpha and Cbeta, with molecular weights of 32,000 and 29,000, respectively. Under nonreducing conditions, the Cbeta chain migrates appreciably more rapidly on sodium dodecyl sulfate/polyacrylamide gels than the reduced Cbeta chain, reflecting the presence of an intrachain disulfide bond. The human DR antigen is also a two-chain unit and contains DRalpha and DRbeta components with molecular weights of 34,000 and 28,000, respectively. The DRbeta chain migrates more rapidly before reduction than afterward, like the murine Cbeta chain. The DRbeta and Cbeta chains are also strikingly homologous if a single amino acid shift is imposed on one of those chains. Thus, human DR antigens strongly resemble the murine I-C subregion antigens.

Amino Acid Sequence↗

Purification and immunologic evaluation of human melnoma-associated antigens.

Melanoma-associated antigens (MAA) were isolated and their functional immunologic properties were evaluated. Spent fetal calf serum-free culture media and 3-m KCI extracts of cultured human melanoma cells grown in this medium were used as antigen sources. Ultracentrifugal flotation on KBr was used to separate MAA and HLA antigens present in the extracts or spent culture media; thus interference by histocompatibility antigens was prevented in subsequent tests of tumor antigenic activity. MAA purified in this manner retained their immunologic functions as evidenced by their ability to produce delayed cutaneous hypersensitivity reactions in patients with melanoma, specifically combine with antimelanoma xenoantibody, and elicit production of functionally specific xenoantibody. Possible structural differences between HLA antigens and MAA were considered in evaluation of the data.

Animals↗

Detection of B cell antibodies in renal transplant recipients.

A retrospective study for the presence of lymphocytotoxic antibodies was performed on sera collected from 119 kidney graft recipients. Sera that had been collected on days 12 to 19 post-transplant were tested for cytotoxic reactions against a panel of human peripheral blood lymphocytes from 60 unrelated donors and 37 to 47 cultured human lymphoid cell lines (LCL). Forty-nine sera were negative against peripheral blood lymphocytes but contained cytotoxic antibody against cells on the LCL panel. Several sera were tested on E rosette-purified peripheral blood lymphocyte B cells and T cells from five donors whose LCL had also been tested. LCL appeared to be more sensitive to cytotoxic reactions than their B cell counterparts and may identify additional specificities which may not be related to the B cell alloantigenic system. Mixed lymphocyte culture blocking experiments were carried out against all combinations of these five cells. Some sera showed reactions of identity for B cells and LCL, and blocked the appropriate stimulator cells in mixed lymphocyte culture. Two sera that were positive for LCL but negative for B cell blocked only responder cells in the mixed lymphocyte culture.

Antibodies↗

A new B cell differentiation antigen (BDA) on normal and leukemic human B lymphocytes that is distinct from known DR (Ia-like) antigens.

A newly defined human B cell differentiation antigen, designated as BDA, has been defined and partially characterized. BDA is expressed on normal human B cells and lymphocytic leukemia cells at all stages of known differentiation (pre-B cells to plasma cells). It is distinct from DR (Ia-like) determinants and other known B cell surface constituents.

Animals↗

Serologic and immunochemical characterization of HLA-A9 xenoantisera.

The specificity of A9 antiserum produced in rabbits immunized with high density lipoprotein-associated HLA-A9 from serum was investigated by using serologic and immunochemical approaches. After suitable absorption, the xenoantiserum No. 2958 is monospecific for A9 antigens in direct cytotoxic test. Data from lysostrip experiments and from blocking of cytotoxicity with Fab2 fragments indicate that the A9 xenoantiserum No. 2958 react with the same or closely associated antigenic structures recognized by A9 alloantisera. Immunoprecipitates obtained with the specific xenoantiserum No. 2958 and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis contained only proteins of the size of detergent-solubilized HLA and beta2-microglobulin (45,000 and 12,000 m.w.). Immunodepletion experiments indicated that the precipitation was mediated by antibodies directed to the heavy chain, and not the light chain of the complex. These results indicate that monospecific HLA-A9 xenoantisera have the same discriminatory capacity of alloantisera and can be useful for the serologic and immunochemical characterization of HLA antigens.

Absorption↗

Human lymphoblastoid cell lines as effector cells in mitogen-dependent and antibody-dependent cell-mediated lysis.

Based on reports that both human and murine lymphoblastoid cell lines can effect lysis in antibody-dependent (ADCC) and mitogen-induced (MICC) cell-mediated cytotoxicity, 10 human lymphoblastoid cell lines were investigated for their ability to act as effector cells in these lytic reactions. Four cell lines promoted MICC and ADCC of chicken erythrocytes. MICC was inhibited by subjecting the effector cells to gamma-irradiation, and ADCC was partially inhibited by treating antibody-coated target cells with Protein A from Staphylococcus aureus. The latter finding suggests that antibody plays a role in the cytotoxic reaction. The lytic activity of cultured human lymphoid cells in both MICC and ADCC reactions was, however, quite variable for unknown reasons. Because of this instability human lymphoblastoid cell lines are not a suitable source of effector cells for studying the biological and molecular properties of structures responsible for the lytic reaction.

Animals↗

Expression of histocompatibility (HLA) antigens on tumor cells and normal cells from patients with melanoma.

The expression of HLA antigens and beta2-microglobulin (beta2-mu) on cultured melanoma cells originated from 11 patients has been quantitated and compared with that on fibroblasts and cultured human lymphoid cells originated from the same patients. No qualitative or quantitative difference was detected with the exception of one melanoma line. HLA antigens were also quantitated in sera from melanoma patients: two sera reacted with anti-HLA-B7 antibodies although this specificity was not expressed on lymphocytes from whom the sera were obtained. A technique to quantitate HLA antigens on cells developed in the course of this study is described.

Cell Membrane↗