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A Bargellesi

Publications and source records attributed to A Bargellesi.

At least 37 records · Page 2Linked to original sources
PubMed1982

A monoclonal anti-DC1 antibody selectivity inhibits the generation of effector T cells mediating specific cytolytic activity.

The products of the DC locus have been shown to be structurally different from those of the DR locus. In this paper it is shown that, unlike anti-DR antibodies, a monoclonal antibody directed against DC1 does not affect proliferation of T cells in response to alloantigens or soluble antigens or production of Ig in a pokeweed mitogen-stimulated in vitro culture. However, the anti-DC1 inhibits the generation of effector T cells mediating specific cytolytic activity, whereas no inhibitory effect can be observed on natural killer and antibody-dependent cytotoxic cell activities.

Antibodies, Monoclonal↗
PubMed1982

In vitro production of IgE by human peripheral blood mononuclear cells. III. Demonstration of a circulating IgE-bearing cell involved in the spontaneous IgE biosynthesis.

The presence of surface membrane IgE (SmIgE)-bearing cells in the peripheral blood (PB) of atopic patients was investigated by the use of isotype-specific rosettes of human red blood cells coupled to immunosorbent-purified rabbit or monoclonal mouse antibodies against human IgE (R or M anti-epsilon-HRBC). After dissociation of cell bound IgE by treatment with acid buffer, 2.1 +/- 0.3% and 1.2 +/- 0.3% circulating non-T, non-phagocytic, cells from atopic patients were still capable of forming rosettes with R or M anti-epsilon-HRBC, respectively. IgE molecules detectable on cells after dissociation of cytophilic IgE were quite resistant, like surface membrane IgM (SmIgM), to treatment with proteolytic enzymes, but they were removed under capping conditions by soluble anti-IgE antisera. All SmIgE-bearing (IgE+) cells also bore DR determinants, but many of them lacked SmIgM. Depletion of IgE+ cells strongly reduced the ability of PB lymphocyte suspensions from atopic patients to produce spontaneously IgE protein in vitro. Likewise, depletion of cells bearing DR determinants (DR+ cells) resulted in a marked decrease of the spontaneous IgE biosynthesis, whereas depletion of SmIgM-bearing (IgM+) cells had no effect. These data suggest that cells mainly implicated in the spontaneous IgE production in vitro seen in atopic patients are DR+ IgE+ IgM- circulating lymphocytes.

Antibodies, Monoclonal↗
PubMed1982

Human T cell subpopulations defined by a monoclonal antibody. I. A small subset is responsible for proliferation to allogeneic cells or to soluble antigens and for helper activity for B cell differentiation.

A monoclonal antibody (5/9) was obtained that reacts with the majority of alloactivated human T cells but only with 15 to 20% peripheral T cells. The populations reactive with the 5/9 antibody were separated from the remaining T cells by rosetting techniques using 5/9-coated ORBC. 5/9+ and 5/9- populations were analyzed for different in vitro activities. The helper activity of PWM- driven B cell differentiation appeared to be restricted and highly enriched in the 5/9+ population. In addition, 5/9+ cells contained all the cells capable of proliferation to tetanus toxoid and allogeneic cells. Thus, in vitro activities commonly used for evaluation of T cell function seem to be confined to a small fraction of peripheral T cells.

Animals↗
PubMed1981

Surface antigens specifically expressed by activated T cells in humans.

By immunizing BALB/c mice with human T cells derived from a secondary mixed lymphocyte reaction (MLR) and successive fusion of the spleen cells with P3X63Ag8U1 myeloma cells, several monoclonal antibodies to activated T cells were obtained. Four of them (MLR 1-4) were shown to be specific for activated T cells only, showing no reactivity with peripheral blood cells. The antigens recognized by these antibodies are differently distributed and appear on T cells at different times after stimulation. Thus, MLR2 stains nearly all the responder T cells present in a secondary MLR, while MLR 1, 3 and 4 stain only a fraction. MLR2 and 3 are also present on mitogen-stimulated cells. At least 3 of these MLR antigens may define different sets of activated T cells, and are likely to become useful in monitoring T cell activation also in the course of diseases involving the immune system.

Animals↗
PubMed1981

Analysis of HLA-DR polymorphism by two-dimensional peptide mapping.

Two-dimensional peptide mapping was used to study the polymorphism of DR antigens, membrane glycoproteins composed of two chains, alpha and beta, and encoded by the human major histocompatibility complex (MHC). Four DR antigens were purified by immunoabsorption from four human lymphoblastoid cell lines homozygous at the DR locus. After labeling with 125I, alpha and beta chains were separated by polyacrylamide gel electrophoresis in sodium dodecyl sulfate and digested with pepsin. Comparison of the peptide maps showed a marked degree of polymorphism among beta chains: only 43% of peptides were common to all four chains and 15-21% of the spots were unique to a given chain. By contrast, only a limited variability was observed among alpha chains. Homology was 75% for the four chains and the percentage of unique peptides was very low. DR7 did not possess even a single unique peptide. The limited variability among alpha chains and the lack of "private" peptides in one of them point to the conclusion that the beta chain is the unique carrier of the alloantigenic specificities. Higher homology within the known crossreactive groups was not observed, suggesting that the determinants responsible for crossreactivity are on different molecules. From a genetic point of view, because beta chains show allele-associated polymorphism, they are likely to be MHC encoded, whereas the minor differences among alpha chains do not allow a similar conclusion. The available data point to an analogy between these DR antigens and the mouse I-E/C antigens.

Alleles↗
PubMed1979

Presence of serum IgD and IgD-containing plasma cells in the mouse.

A new technique which makes use of anti-delta-specific allo-or heteroantisera coupled to Sepharose 4 B has been employed to investigate the presence of IgD molecules in the sera of three mouse strains. The sera were reacted with the insoluble immunosorbents, and the eluted material was labeled with 125I prior to antigenic or sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. This material reacted with anti-delta or anti-L chain reagents, but not with other anti-class-specific antisera and, after reduction, was resolved in three discrete bands in SDS-PAGE. The fastest of these bands comigrated with L chain, whereas the other two moved identically to mouse lymphocyte surface delta chains. Immunofluorescence studies on fixed smears of spleen and Peyer's patches' cells revealed the presence of a small but consistent number IgD-containing plasma cells.

Animals↗
PubMed1979

Characterization of IgD. II. Molecular forms of IgD in human B cells.

Endogenous and surface labeling techniques were used on human lymphoid cells to characterize intracytoplasmic, membrane and secreted IgD, IgD synthesized by lymphocytes and inserted into the cell membrane displayed a single molecular form with the same mobility in sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) as the previously described slow migrating serum IgDl. Plasma cells produced and secreted IgDl and another IgD corresponding to the faster-moving serum IgD2. Conversion of one molecular form into the other was never observed, thus indicating that neither molecule is a precursor or a degradation product of the other.

Autoradiography↗
PubMed1979

Characterization of IgD. I. Isolation of two molecular forms from human serum.

Human IgD present in the serum of normal individuals or of patients with Hodgkin's disease (having high IgD concentrations) was characterized and compared with five IgD myeloma proteins. IgD was isolated using a highly specific anti-delta insoluble immunoabsorbent from which the bound material was eluted with sodium dodecyl sulphate (SDS) or urea. The latter reagent could be removed by extensive dialysis, thus making possible the renaturation of the eluted molecules. The purity of the IgD thus isolated was confirmed by antigenic analysis. Both kappa and lambda light chain determinants were present on serum IgD, although lambda light chain was predominant with a ratio over the kappa chain of 2:1. SDS-polyacrylamide slab gel electrophoresis analysis revealed two different molecular forms of serum IgD, one (IgD) migrating identically to monoclonal IgD, the other (IgD2) having a faster mobility. The difference between the two molecules was entirely, due to the different sizes of their constituent delta chains. Peptide mapping of the two chains (delta1 and delta2 respectively) and of the delta chain of an IgD myeloma protein was carried out using 125I-labelled material. The three molecules displayed a high degree of homology, the delta2 chain differing by the presence of three characteristic extra peptides. The significance of these extra peptides is discussed in the light of the peptide mapping technique employed.

Autoradiography↗
PubMed1978

Correlation of serum IgD level with clinical and histologic parameters in Hodgkin disease.

The concentration of serum IgD was measured in 100 patients with Hodgkin disease; 65 had 3--50-fold increases in IgD levels. Several parameters were found to influence serum IgD concentration: IgD level in older patients (greater than 50 yr) was significantly lower than in the younger patients (P less than 18 yr). IgD concentration was significantly higher in splenectomized than in nonsplenectomized patients (p less than 0.005). Therapy was found to depress IgD concentration, which fell to a value significantly lower than in untreated patients (p less than 0.05). An interesting correlation was found between IgD levels and histologic type of the disease, lower levels being preferentially associated with the lymphocyte predominance type and higher with the lymphocyte dipletion type. The logarithms of the means of these two groups were significantly different from the overall mean of the disease (p less than 0.05 and p less than 0.0005, respectively). Mixed cellularity and nodular sclerosing showed intermediate values.

Aging↗
PubMed1977

Increased serum IgD concentrations in patients with Hodgkin's disease.

Serum IgD concentrations have been determined in twenty-one patients with Hodgkin's disease, in eight patients with non-Hodgkin's lymphomas and in twenty-eight normal (control) individuals by both a solidphase radio-immuno-assay and radial-immunodiffusion. Fourteen of the Hodgkin's patients displayed three to forty-five-fold increased serum IgD levels as compared to control individuals, while in the remaining seven patients IgD concentrations were practically normal. Patients with non-Hodgkin's lymphomas had decreased IgD concentrations.

Hodgkin Disease↗
PubMed1976

Membrane Ig on MPC11 myeloma cells: correlation between the expression of membrane Ig, a receptor for Ig and the process of secretion.

The expression of membrane immunoglobulin (mIg) was examined in three cloned MPC11-derived mouse myeloma cell lines. Membrane immunofluorescence studies demonstrated that IgG2b producer cells (P1) had complete IgG molecules, L-chain producer (L1) had only L-chain determinants and nonproducer (NP2) did not have any Ig determinants on the cell surface. An Ig receptor, with characteristics different from B lymphocyte Fc receptor, has been found to be present on secreting cells (P1 or L1), but not on the NP2 cell variant. The data reported in the present paper indicate that the expression of mIg and of the Ig receptor molecule is clearly correlated with the process of secretion. In the light of previous data reported on Ig secretion, a model is proposed which correlates the process of secretion with the expression not only of mIg, but also of the receptor for Ig.

Binding Sites, Antibody↗
PubMed1976

Membrane Ig on human lymphocytes: rate of turnover of IgD and IgM on the surface of human tonsil cells.

The turnover of IgM and IgD molecules present on the membrane of human tonsil cells has been studied using immunofluorescence and peroxidase-catalyzed membrane radioiodination. With the first of the two techniques cells were treated with pronase to remove membrane immunoglobulin (mIg), placed in culture and stained at intervals to check the reappearance of membrane IgD and IgM on the cell membrane. These experiments showed that membrane IgD (in contrast to membrane IgM) are extremely susceptible to proteolysis. Furthermore, cells treated with a concentration of pronase found to be optimal to remove membrane IgM failed to re-express membrane IgD in vitro. The large majority of tonsil lymphocytes has both membrane IgM and IgD. Due to the different behavior of reappearance of the two membrane molecules after treatment with pronase, it was not possible to obtain the simultaneous re-expression of membrane IgM and IgD by the cells "stripped" with pronase. However, the two molecules were re-expressed in vitro by the cells treated with different pronase concentrations with a similar timing, i.e. 50% or more of the cells re-expressed membrane IgD and IgM after 8 h in culture. 131I-radioiodinated membrane IgD and IgM were also released from the cell surface with a similar timing, the half-life of permanence on the cell membrane being about 4 h for both molecules. These findings thus indicate that IgM and IgD molecules have a similar turnover and that a cell is capable of placing two different Ig molecules at a time on its surface.

Cells, Cultured↗
PubMed1976

Synthesis of immunoglobulin by substrate attached mouse myeloma cells.

Cultured mouse myeloma cells grow in suspension and synthesize and secrete large amounts of immunoglobulin. Mouse myeloma cells which attach to a plastic substratum have been obtained by mutagenesis and subsequent selection. Normal mouse myeloma cells will also attach to plastic tissue culture dishes pre-treated with poly-L-lysine. The attached cells synthesize and secrete the same large amounts of immunoglobulin as the suspended cells.

Acridines↗
PubMed1975

Comparative study of membrane and intracytoplasmic immunoglobulin classes in human lymphoid cells.

Immunofluorescent and "in vitro" biosynthetic techniques have been used to study the connections between the maturation process of human lymphocytes that leads to the appearance of actively secreting cells and a possible switchover from IgD to IgM production, both in homogeneous CLL cell populations and in heterogeneous cell suspensions from tonsils. The results obtained are compatible with the hypothesis that the switchover from IgD to IgM productions can be a clonal maturation phenomenon.

Antibody-Producing Cells↗