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Biomedical subjects

S Ferrone

Publications and source records attributed to S Ferrone.

At least 397 records · Page 22Linked to original sources

Immunochemical characterization of a human B lymphocyte differentiation antigen (p65).

A human B-cell differentiation antigen (BDA-1) with a molecular weight of 65,000 was identified by use of an anti-B-cell xenoantiserum. BDA-1 was isolated by immunoprecipitation of cell lysates from a B-lymphoblastoid cell line (SB) and from blood B lymphocytes (sIg+ER-) of four normal individuals. It was not detectable in cell membrane lysates from two T-lymphoblastoid cell lines (HSB-2 and MOLT-3) or from enriched normal T cells (sIg-ER+). BDA is single-chain molecule since its migration in SDS-PAGE gels was not altered by heating the protein to 100 degree C or by treatment with 2-mercaptoethanol. Immunodepletion experiments demonstrated that the antigen recognized by anti-BDA xenoantiserum has neither structural nor antigenic relationships with Ia-like antigen or beta 2-microglobulin.

Antibodies↗

Human and murine tumours: changes in cell surface structures coded by the major histocompatibility complex region.

Serological and structural changes of surface markers involved in immune reactions may occur in human and murine tumour systems. Thus nine out of twenty-one human tumour cell lines and SV40-transformed fibroblasts differed from autologous lymphoblastoid cells or fibroblasts in their reactivity with HLA alloantisera. H-2 antigens isolated from the murine tumour cells 6C3HED and TP1422, undergo structural changes. An alien HLA-B7 was detected in sera from two melanoma patients. The serologic activity of H-2 antigens was significantly increased in the serum and ascites fluid of tumour bearing mice. Additionally, human SV40-transformed fibroblasts acquire receptors for monkey red blood cells and the murine lymphosarcoma cells 6C3HED express receptors for sheep red blood cells.

Animals↗

Xenoantisera to DRw allospecificities.

The specificity of DR xenoantisera was assessed by testing them with a panel of HLA typed B-lymphocytes in a cytotoxic test with rabbit or human complement. The pattern of reactions of some xenoantisera correlated with DR allospecificities. These results confirm that injection of DR antigens across species barrier can elicit antibodies to DR allospecificities.

Animals↗

Fab2 fragments from HLA xenoantisera specifically block cytolysis mediated by HLA-AB alloantisera.

Fab2 fragments from antisera raised in rabbits with partially purified cellular and serum HLA antigens were tested for their ability to block the cytolytic activity of operationally specific HLA-A,B alloantisera. One Fab2 fragment preparation blocked the cytolytic activity of all the HLA-A,B alloantisera tested; the remaining nine inhibited the lytic activity of alloantisera to certain HLA-A,B allospecificities, suggesting that these xenoantisera contain antibody to certain HLA-A,B allotype determinants or to closely associated structures. In contrast to previous reports in the literature none of the xenoantisera contained significant amounts of antibodies to human beta 2-microglobulin.

Animals↗

Cytotoxicity of anti-beta 2-microglobulin xenoantisera to human and murine myeloid progenitor cells and lack of cross-reactivity with colony-stimulating activity.

A previous report has suggested an antigenic relationship between beta 2-microglobulin (beta 2 mu) and granulocyte colony-stimulating activity (CSA). Since human myeloid progenitor cells (CFU-C) express HLA antigens and beta 2 mu is a known molecular component of HLA antigens, we wondered whether the reported effect of anti-beta 2 mu heteroantisera on in vitro granulopoiesis might result from cytotoxicity to CFU-C rather than from cross-reactivity with CSA. To test this, we used rabbit antibody reactive with human and murine beta 2 mu (anti-beta 2 mu). Treatment of human and murine bone marrow cells with anti-beta 2 mu and complement resulted in 95+% inhibition of CFU-C colony formation compared to controls. To test for an effect on CSA, anti-beta 2 mu was incubated with human and murine sources of CSA. After addition of goat anti-rabbit Ig antiserum to precipitate immune complexes and unbound anti-beta 2 mu, the supernatant fluid retained CSA but was no longer cytotoxic to CFU-C. These results indicate that human and murine CFU-C express membrane beta 2 mu and that anti-beta 2 mu antibody does not cross-react with human or murine CSA.

Animals↗

Purification of immunologically functional subsets of human Ia-like antigens on a monoclonal antibody (Q5/13) immunoadsorbent.

Serologic and immunochemical asays have shown that the monoclonal antibody Q5/13 recognizes an antigenic determinant expressed on a subset of human Ia-like antigens. Testing with a panel of HLA typed B lymphoid cells has shown that this determinant is different from those defining the serologic polymorphism of HLA-DR antigens. The monoclonal antibody Q5/13 has been used to purify subsets of human Ia-like antigens, which are immunologically functional. These reagents should facilitate the characterization of structural and functional properties of human Ia-like antigens.

Antibodies↗

Monoclonal antibodies to HLA-A,B, and Ia-like antigens inhibit colony formation by human myeloid progenitor cells.

Hybridomas derived from the fusion of murine myeloma cells with splenocytes from mice immunized with human cultured lymphoid cells secreted monoclonal antibodies to human cell surface antigens. Serologic and immunochemical assays showed that 4 monoclonal antibodies (Ab Q2/47, Q2/61, Q2/70, Q2/80) recognize framework determinants of Ia-like antigens and 1 monoclonal antibody (Ab Q1/28) reacts with determinants expressed on the heavy chain of HLA-A,B antigens. Both anti-HLA-A,B and anti-Ia-like antigen monoclonal antibodies caused complement-dependent inhibition of granulocyte-macrophage colony formation by human bone marrow grown in soft agar. Mixing experiments excluded the possibility of an indirect effect on progenitor cells by lysis of auxiliary cells. These results indicate that human myeloid progenitor cells express HLA-A,B and Ia-like antigens.

Animals↗

Appearance of receptors for Macaca speciosa red blood cells on human fibroblasts transformed by simian virus 40.

Receptors for monkey red blood cells (MRBC) that are expressed on subpopulations of human lymphoid cells are coded by genes linked to the major histocompatibility complex (MHC) region. Since malignant transformation of cells is associated with changes in structures coded by the MHC region, 10 cultured human melanoma and sarcoma cells and autologous SV40-transformed fibroblasts were tested for expression of MRBC receptors and compared with normal autologous fibroblasts. Only 2 of the tumor cell lines and normal fibroblasts from the same individual formed rosettes with MRBC. On the other hand, SV40 transformation induced in all the fibroblasts expression of receptors for MRBC. MRBC receptors on SV40-transformed fibroblasts show properties similar to those on B lymphoid cells.

Animals↗

Indirect rosette microassay to characterize human melanoma-associated antigens recognized by operationally specific xenoantisera.

The indirect rosette assay which detects the interaction of antibodies with target cells by their ability to rosette with sheep red blood cells chemically coated with purified anti-immunoglobulin antibodies or with protein A from Staphylococcus aureus has been used to analyze xenoantisera to human melanoma-associated antigens. The test has been developed as a microassay and performed in microtiter plates, thus facilitating the screening of large numbers of samples. When modified as an inhibition assay, the assay has been successfully used (a) to compare the specificities of xenoantisera elicited with cultured melanoma cells, hybrids derived from the fusion of cultured human melanoma cells, and murine fibroblasts and melanoma-associated antigens purified by biochemical procedures and (b) to investigate the relationship of melanoma-associated antigens with beta 2-microglobulin and HLA antigens on the membrane of melanoma cells.

Antibodies, Anti-Idiotypic↗

Structural polymorphism of human DR antigens.

DR ANTIGENS are polymorphic cell surface molecules whose expression is controlled by a locus closely linked or identical to the D locus of the major histocompatibility complex (MHC) of man (for reviews see refs 1, 2). They are functionally and structurally homologous to the murine la antigens determined by the I-E subregion of the MHC, a region which has been implicated in the genetic control of immune responses(3,4). Both sets of antigens are mainly expressed on cells associated with immune function (for reviews see refs 1, 2, 5), and are involved in mediating T-cell, B-cell and macrophage interactions required for the generation of immune responses(6-9). In addition, both consist of two non-covalently associated polypeptides, designated alpha and beta, with molecular weights of 34,000 and 28,000, respectively(10). The association of some DR antigens with increased susceptibility to certain diseases (for review see ref. 1) and the genetic restrictions imposed on cellular interactions by the HLA-D region(9,11) may represent the effects of structural variability among DR antigens. The aim of the studies reported here was to examine the nature and degree of structural variation among DR antigens isolated from cultured lymphoid B cells with different DR phenotypes. Such information may provide an understanding of the molecular mechanisms by which DR antigens mediate their function.

Journal Article↗

DR (Ia-like) antigens on human melanoma cells. Serological detection and immunochemical characterization.

11 cultured human melanoma cell lines were tested for the expression of DR antigens by using specific allo- and xenoantisera in an indirect rosette microassay. Four of these melanoma cell lines expressed DR antigens, but in lower amounts than expressed on cultured human B-lymphoid cells. Rabbits injected with the DR-positive melanoma cells produced antibodies that were serologically and immunochemically reactive with B-cell-derived DR antigens. Immunochemical studies indicate that melanoma cell-derived DR antigens have a two-chain structure with 34,000 and 27,000 mol wt components. The melanoma cell-derived DR beta-chain at 27,000 mol wt is slightly smaller than that of the Victor cell DR beta-chain whose mol wt is 29,000.

Antigens, Neoplasm↗