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V Quaranta

Publications and source records attributed to V Quaranta.

At least 109 records · Page 6Linked to original sources
PubMed1981

Expression of Ia-like antigens in normal human nonlymphoid tissues.

Recent results have demonstrated that Ia-like antigen expression in animal tissues is not restricted to cells associated with immune functions. Whether this phenomenon occurs in normal human tissues has been investigated in this study by indirect immunofluorescence on cryostat sections using monoclonal antibodies to framework determinants of Ia-like antigens. The results of this study show that Ia-like antigens are expressed on several normal human tissues of different embryonic origin. These include the epithelium of the gastrointestinal tract, urinary bladder, bronchial glands, thymic reticuloepithelial cells (entodermic origin), epithelium of mammary gland, acinar cells of parotid, astrocytes (ectodermic origin), alveolar macrophages, Kupffer cells, glomerular and peritubular renal endothelium, endometrium, and Langerhans cells (mesodermic origin).

Cell Line↗
PubMed1981

Effect of tunicamycin on the assembly and antigenicity of HLA antigens: analysis with monoclonal antibodies.

The effect of glycosylation on the assembly and antigenicity of HLA antigens was investigated by examining HLA antigens synthesized in the presence of the antibiotic tunicamycin, an inhibitor of asparagine-linked oligosaccharide addition, with monoclonal antibodies specific for a variety of antigenic determinants. The monoclonal antibody Q5/13 reactive with a determinant expressed on the beta chain of human Ia-like antigens immunoprecipitated alpha and beta subunits with reduced apparent molecular weights from tunicamycin-treated cells, indicating that glycosylation is not required for association of the Ia-like antigen alpha and beta subunits. Immunoprecipitation of HLA-A,B,C antigens from tunicamycin-treated cells with four monoclonal antibodies specific for the heavy chain and one specific for beta 2-microglobulin showed that the heavy-chain determinant detected by the antibody Q6/64 is absent from the non-glycosylated molecule. This is the first demonstration that carbohydrate addition during biosynthesis affects the protein conformation of the HLA-A,B,C heavy chain.

Antibodies, Monoclonal↗
PubMed1981

Characterization of human null cells isolated from peripheral lymphocytes by a simultaneous double-rosetting procedure.

Human null cells were isolated from peripheral blood lymphocytes (PBL) by differential centrifugation on a Ficoll-Hypaque gradient of the PBL following simultaneous rosetting with erythrocyte indicators specific for B and T lymphocytes. Specifically, the T lymphocytes were rosetted with 2-aminoethylisothiuronium bromide-treated sheep erythrocytes (ShE), whereas the B lymphocytes were either rosetted with ShE coated with xenoantibodies against human gamma globulin or first sensitized with monoclonal antibodies to human Ig-like antigens and then rosetted with ShE coated with xenoantibodies against mouse gamma globulin. Approximately 90% of the lymphocytes isolated were null cells that did not bear detectable B-cell markers-that is, surface immunoglobulin and/or Ia-like antigens-or T-cell markers-that is, ShE receptors. The large majority of the null cells expressed receptors for the IgG Fc fragment (53-93%), C3 component (65-92%) and monkey erythrocytes (60-91%) but lacked receptors for the IgM Fc fragment and murine erythrocytes. The null cells exhibited high natural killer cell activity and antibody-dependent cellular cytotoxicity and were two- to four-fold active than the total PBL and the T-enriched cell fractions. The null cells, however, did not respond to stimulation with phytohaemagglutinin and failed to function as either stimulators or responders in an unidirectional mixed lymphocyte reaction.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1981

Serologic and immunochemical characterization of the specificity of four monoclonal antibodies to distinct antigenic determinants expressed on subpopulations of human Ia-like antigens.

Serologic and immunochemical assays showed that the monoclonal antibodies Q2/70, Q2/80, Q5/6, and Q5/13 react with human Ia-like antigens. Each monoclonal antibody recognizes distinct antigenic determinants that are different from those defining the serologic polymorphism of Ia-like antigens defined by conventional alloantisera and are expressed on subpopulations of Ia-like antigens. The determinants recognized by the MoAb Q2/70 and Q5/13 are expressed on all HLA-DR allospecificities tested, whereas those reacting with the MoAb Q2/80 and Q5/6 are not detectable on HLA-DR5 and HLA-DR7 allospecificities, respectively.

Antibodies↗
PubMed1981

Lysis of cultured human melanoma M10 cells by polyclonal xenoantibodies to melanoma-associated antigens.

Cultured human melanoma cells M10 harvested from cultures in different phases of their growth show significant changes in the expression of melanoma-associated antigens (MAA), but they do not vary in susceptibility to lysis mediated by anti-MAA xenoantisera and effected by complement or lymphoid cells. Furthermore, melanoma cells M10 showed a significant increase in susceptibility to immune lysis following treatment with puromycin at doses that do not effect the expression of MAA. The lack of correlation between MAA density and susceptibility to immune lysis supports the contention that, under the experimental conditions used, cellular properties play a major role in the outcome of immune attack.

Antibodies, Neoplasm↗
PubMed1980

Serological, functional, and immunochemical characterization of a monoclonal antibody (MoAb Q2/70) to human Ia-like antigens.

Serological and immunochemical studies showed that monoclonal antibody Q2/70 (MoAb Q2/70), produced by the hybridoma technique, is specific for human Ia-like antigens. This antibody recognizes an antigenic determinant which is different from those defining the serologic polymorphism of Ia-like antigens, and is expressed on subsets of human Ia-like molecules and on lymphoid cells from other species. MoAb Q2/70 inhibits unidirectional MLRs* between allogenic human lymphocytes, but not between murine and human lymphocytes. In ADCC* assays. MoAb Q2/70 mediates lysis of cultured human B lymphoid cells RPMI 4098, effected by murine splenocytes. The antibody is suitable to isolate immunologically functional B lymphocytes from human peripheral blood.

Animals↗
PubMed1980

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↗
PubMed1980

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↗