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Biomedical subjects

N Chiorazzi

Publications and source records attributed to N Chiorazzi.

At least 91 records · Page 5Linked to original sources
PubMed1985

Stimulation of a subset of normal resting T lymphocytes by a monoclonal antibody to a crossreactive determinant of the human T cell antigen receptor.

A previous study from this laboratory described a monoclonal antibody, S511, that reacted with the T cell antigen receptor on a human T cell leukemia and also on 1-2% of circulating T lymphocytes in all normal individuals tested. The data presented in the present study demonstrate that, when normal T lymphocytes are cultured with or without irradiated non-T cells in the presence of soluble S511 antibody, a concentration- and time-dependent proliferation of the S511-reactive population occurred. Proliferation indices as high as 184 times greater than control were observed, which represents a major stimulatory effect on the initially minor S511+ subset. When S511+ cells were studied for evidence of prior activation, they were shown to be unresponsive to interleukin 2 (IL-2) unless exposed to S511 antibody, and were shown to be in the G0/G1 phase of the cell cycle. Thus, the S511 antibody activated resting normal T cells in a manner analogous to specific antigen binding to the T cell antigen receptor. The leukemic S511 molecule has been shown previously to differ from most other antigen receptors in the mobility of the two chains at 43 and 38 kD and the neutral isoelectric point of each chain. Expansion of reactive normal cells by S511-Sepharose permitted the development of IL-2-dependent T cell lines enriched for S511-bearing cells. The antigen receptor molecules on one such polyclonal S511-enriched T cell line were immunoprecipitated with S511 antibody and shown to have comparable mobility to that present on the leukemic cells, but to possess a greater heterogeneity of mobility. Thus, the leukemic cells and normal cells express similar T cell receptor molecules. The differences in the S511 T cell antigen receptor molecule possibly relate to differences in glycosylation or polypeptide structure.

Antibodies, Monoclonal↗
PubMed1985

Temporal shifts from Sm to ribonucleoprotein reactivity in systemic lupus erythematosus.

The Sm and RNP autoantibodies, found in the sera of many patients who have connective tissue diseases, recognize determinants on small nuclear ribonucleoprotein particles (snRNP). Numerous techniques have been used to distinguish between the subsets of snRNP proteins recognized by these two antibody systems. Using protein and snRNP immunoprecipitation, as well as a competitive enzyme-linked immunosorbent assay, antibodies in the sera of Sm patients have been observed to include variable quantities of RNP-like reactivity. To analyze changes in these autoantibodies, 2 patients with anti-Sm antibodies were followed temporally. The autoantibodies in the sera of both patients underwent shifts from predominant Sm reactivity to predominant RNP reactivity. In 1 patient the shift occurred gradually over several years, while in the other the shift occurred within 8 weeks.

Adult↗
PubMed1985

Biochemical characterization and purification of human B cell stimulatory factor (BSF).

B cell stimulatory factor (BSF) activity was generated over a period of five days by phytohemagglutinin-stimulated E rosette-positive peripheral blood lymphocytes. This activity was subjected to a multistep purification procedure including ammonium sulfate precipitation, anion-exchange chromatography, gel filtration, procion red-agarose chromatography and reverse phase high performance liquid chromatography (RP-HPLC). The last purification step dissected BSF activity into two active fractions, one corresponded to the interleukin 2 (IL 2) activity whereas the other active fraction was free of IL 2 activity. Preparative isoelectric focusing analysis defined isoelectric points of pH 7.2 for both BSF and IL 2. Molecular weight analysis of BSF was carried out by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. BSF activity was eluted from gel strips corresponding to a molecular mass of 16 and 17 kDa. The 16-kDa fraction was free of IL 2 activity whereas the 17-kDa fraction overlapped with IL 2. Since recombinant IL 2 was capable of exhibiting significant BSF activity in anti-IgM or Staphylococcus aureus Cowan strain I-dependent assay systems, it cannot be excluded that IL 2 itself is a BSF. Nevertheless these studies demonstrate the existence of a BSF free of IL 2 activity.

Antibodies, Anti-Idiotypic↗
PubMed1984

Human B-cell-stimulatory-factor production by both T4+ and T8+ lymphocytes.

The T-cell subsets responsible for the production of human B-cell-stimulatory factor (BSF) have been identified. Peripheral blood mononuclear cells (PBMNC), E-rosette-forming cells, and isolated T4+/T8+ subpopulations were cultured for 5 days with and without phytohemagglutinin (PHA) stimulation; the supernatants were then assayed for BSF. BSF activity was detected by a costimulation assay using either Staphylococcus aureus Cowan I (SAC) or goat anti-human IgM as a B-cell comitogen. Supernatants from all four PHA-stimulated cell preparations were found to exhibit BSF activity. However, supernatants from the unseparated PBMNC showed a kinetic pattern for BSF production different from that of the E-rosette-enriched T-cell population in that the BSF activity of the former reached a maximum at Day 2, followed by a rapid decrease, whereas BSF production by the latter reached a plateau at Days 4-5. Although BSF activity was observed in supernatants from both T4+- and T8+-stimulated T-cell subsets, supernatants from T8+ cells contained 50% less activity than supernatants from T4+ cells. Supernatants from the unstimulated fractions and the mitogen-containing medium control did not exhibit BSF activity. These results indicate that both the helper and the suppressor cell fractions, i.e., T4+ and T8+ lymphocytes, are responsible for the production of BSF. However, it is unclear whether the BSF activities detected in both T-cell subsets are mediated by the same or different molecular entities.

B-Lymphocytes↗
PubMed1984

T cell antiidiotypic antibodies reveal differences between two human leukemias.

Two different human T cell leukemias were compared, using antiidiotype-like murine monoclonal antibodies. In each case these antibodies immunoprecipitated disulfide-linked heterodimer molecules from their respective leukemic cells. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the two idiotype-bearing molecules a major difference in molecular weight was observed, which could be attributed to a similar difference in size of the heavily iodinated chain of either heterodimer. The lightly iodinated chains of both molecules co-migrated at 43 Kd, but appeared to have different isoelectric points on two-dimensional gel analysis. The possibility that these two different heterodimers correspond to different classes of the putative T cell receptor for antigen is discussed. Assays of proliferation of the leukemic cells using Sepharose-bound antiidiotype-like monoclonal antibody showed that one of the leukemic cell types proliferated readily in response to its antiidiotypic antibody. This proliferation was not associated with measurable production of IL-2 and appeared to be a direct effect of the antiidiotypic antibody, which may mimic antigen in its interaction with the T cell receptor for antigen. The other leukemic cell type did not respond to Sepharose-bound antiidiotypic antibody and was generally unresponsive to lymphokines and mitogens. It is possible that the two leukemic cell types represent different stages of T cell differentiation.

Animals↗
PubMed1984

Preparation and characterization of monoclonal antibodies recognizing three distinct differentiation antigens (BL1, BL2, BL3) on human B lymphocytes.

We report in this paper the generation and characterization of three monoclonal antibodies, designated alpha BL1, alpha BL2, and alpha BL3, that recognize distinctive antigens unrelated to complement, Fc, and mouse erythrocyte rosette receptors, which are preferentially expressed on B lymphocytes. alpha BL1 recognizes a heat stable nonimmunoprecipitable antigen, possibly glycolipid in nature. Alpha BL2 recognizes a nonreducible single polypeptide with a m.w. of 68,000 that occasionally co-precipitates with a p29,34 complex of HLA-DR antigens. Alpha BL3 recognizes a nonreducible single polypeptide with a m.w. of 105,000 with an acidic pI point. We demonstrated that BL1 is expressed on fetal liver hematopoietic cells, a small subset (5 to 15%) of Ficoll-Hypaque-separated normal bone marrow cells, and on a subpopulation of nonadherent, non-E rosette-forming cells and granulocytes. BL2 is expressed on fetal liver hematopoietic cells, on 3 to 7% of normal bone marrow cells, and on a majority (40 to 70%) of nonadherent, non-E rosette-forming cells with a distinctive pattern similar to that of HLA-DR. BL3 is expressed on a subpopulation of nonadherent, non-E rosette-forming cells, and on occasional cells in the monocyte-enriched adherent cell population. The peak fluorescence for BL2 is substantially higher than that of BL1 and BL3, indicating higher BL2 antigen density. All three antigens are absent from thymocytes and E rosette-positive T cell fractions obtained from various lymphoid tissues. Cellular distribution of the BL antigens on various well-characterized established hematopoietic cell lines, leukemias, and malignant lymphomas, in conjunction with the results of the in vitro activation and TPA-induction experiments, suggest that BL1 is expressed during early developmental stages of B cell differentiation, whereas BL3 is expressed at the later stages. BL2 expression spans immature and mature stages of B cell differentiation, with the exception of mature plasma cells. The alpha BL antibodies described here should prove to be useful in the investigation of B cell differentiation and in the clinical diagnosis of lymphoid neoplasms.

Animals↗
PubMed1984

An antigen characteristic of hairy cell leukemia cells is expressed on certain activated B cells.

A murine monoclonal antibody, anti-HC2, which reacts with hairy cell leukemia cells, was used to define the normal cell equivalent for the leukemic hairy cell. This antibody stained the membranes of 2.24% of normal peripheral blood lymphocytes. These cells were more common in T cell-depleted cell populations, and bore membrane immunoglobulin. Some B lymphoblastoid cell lines were also anti-HC2-positive. Examination of normal B cell subpopulations revealed that HC2-positive cells frequently co-express an activation antigen and membrane IgG. Cell populations enriched for HC2-positive cells contained the bulk of PWM-responsive B cells. These data suggest that HC2-bearing B cells are activated B cells. B cell differentiation induced in vitro by PWM with T cell helper factors resulted in an increase in the number of HC2-positive cells at day 4 or 5 of culture. The HC2-positive cells were no longer present at the time of maximal plasma cell differentiation on day 7 of culture. By using B cells from a patient with the hyper-IgM syndrome that are incapable of immunoglobulin heavy chain class switching, it was demonstrated that HC2 expression did not require prior heavy chain switch. The m.w. of the HC2 antigen was 52 to 63 KD. Four bands with different isoelectric points were discerned on two-dimensional analysis. We suggest that hairy cell leukemia represents a malignancy of activated B cells. A unique stage of B cell differentiation is identified by the HC2 activation antigen.

Antibodies, Monoclonal↗
PubMed1983

Familial systemic lupus erythematosus in males.

Several families in which systemic lupus erythematosus predominates in males are presented. The disease primarily manifested itself in the sons and in the male parents. Females in some of the families had other autoimmune diseases such as idiopathic thrombocytopenic purpura or symptoms suggestive of a lupus diathesis. It is suggested that the sons inherited the disease from their fathers in these families. The disease in the patients had some similarity to the disease in BXSB mice.

Adolescent↗
PubMed1982

Use of Epstein-Barr virus-transformed B cell lines for the generation of immunoglobulin-producing human B cell hybridomas.

HGPRTase-deficient EBV-transformed B cell lines were shown to be effective fusion partners with mitogen-activated human B cells for the construction of Ig-producing human B cell hybridomas. In a series of experiments using these lines and B cells from several tissue sources, approximatley 20% of the cultures plated were consistently positive for growth after hypoxanthine-aminopterin-thymidine selection and approximatley 30% of these synthesized significant new Ig. A marked increase in Ig secretion was observed after hybridization, which was due to new Ig; Ig from the parental lime was shown to disappear in several instances. Special analyses were carried out on a human hybridoma secreting antibody specific for tetanus toxoid and tetanus toxin and stable subclones were derived. These studies suggest that EBV-transformed lines will prove useful in human hybridization studies, thus making a large library of B cell lines available for the generation of human monoclonal antibodies.

B-Lymphocytes↗
PubMed1982

Monoclonal antibodies with specificity for hairy cell leukemia cells.

Hairy cell leukemia is a well described clinical entity, but the cell of origin for this leukemic cell and its function are still unknown. There are no totally specific markers for this cell, although tartrate-resistant acid phosphatase staining has been used extensively as a diagnostic test. This study describes three monoclonal murine antibodies with variable specificity for hairy cells. Antibody 1 was highly specific for hairy cells and was not found to react with normal or leukemic cells in this limited study. It did not react with the cells of all patients. It also did not react with all of the hairy cells of some of the positive cases. Antibodies 2 and 3 reacted with virtually all hairy cells but not with normal peripheral blood cells. However, reactions were obtained with certain leukemic myelomonoblasts and some activated B cells. The most obvious use for these three antibodies is for diagnostic purposes. They should also be helpful reagents to investigate the origin of the leukemic hairy cell. The possibility that antibody 1 detects a tumor-specific antigen is discussed.

Antibodies, Monoclonal↗
PubMed1979

Induction of polyclonal antibody synthesis by human allogeneic and autologous helper factors.

Human helper factors were obtained from supernates of 48 h unidirectional allogeneic and autologous mixed lymphocyte reactions. These supernates were shown to induce the production of large amounts of immunoglobulin by tonsillar and peripheral blood mononuclear cells. Abundant polyclonal activation to antibody production occurred in these cultures in the absence of antigenic challenge which was similar in degree to that produced by pokeweed mitogen. This was documented by quantitating plasma cells, specific plaque-forming cells, and secreted immunoglobulin. In addition, the supplementation of companion cultures with sheep erythrocytes resulted in a significant enhancement of the specific plaque-forming cell response without an appreciable change in plasma cell number of secreted Ig.

Antibody Formation↗
PubMed1979

Immunological properties of conjugates of ragweed pollen antigen E with methoxypolyethylene glycol or a copolymer of D-glutamic acid and D-lysine.

The major allergen of ragweed pollen, antigen E, was modified by coupling its amino acid groups with either methanol, methoxypolyethylene glycol (MPEG) of 5,000 daltons, or a synthetic copolymer of D-glutamic acid and D-lysine (DGL) of 34,000 daltons, all appropriately activated. The conjugates were characterized chemically and immunologically. Compared to the native antigen, the methoxy conjugate showed little reduction in allergenic activity, but the other two conjugates showed strong reductions, as measured by heterologous passive cutaneous anaphylaxis in rats sensitized with murine anti-antigen E reaginic sera. The MPEG conjugate was apparently nonimmunogenic in mice known to be high responders to the native antigen. MPEG and DGL conjugates retained the immunosuppressive property of the native antigen as subcutaneous treatment of antigen E sensitized mice with these two conjugates led to significant long-lasting depression of their antigen E-specific IgE and IgG antibody levels. These immunological changes are believed to result from reduction of antigenic valency and specificity upon coupling the bulky molecules to the protein antigens.

Animals↗
PubMed1979

Induction of human antibody responses in vitro with emphasis on allogeneic helper factors.

Systems have been developed for the reproducible production of antigen-specific plaque forming cells for both tonsillar and peripheral blood B cells. Allogeneic helper activity was an essential supplement and monocyte removal was important, especially in the peripheral blood situation. Highly active allogeneic helper factors could be obtained from undirectional MLC supernatants which aided the proeuction of antigen-driven plaques. These factors also caused a polyclonal activation of B lymphocytes. A number of clinical applications of the above system were described. A defect in the T cells of patients with chronic lymphocytic leukemia with respect to the generation of helper activities was delineated.

Antibody Formation↗