bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deficiency of the C3b/C4b receptor (CR1) of erythrocytes in systemic lupus erythematosus: analysis of the stability of the defect and of a restriction fragment length polymorphism of the CR1 gene.
Authors: Wilson J G , Wong W W , Murphy E E , Schur P H , Fearon D T 
Published: December 2022

Abstract
The role of genetic factors in controlling CR1 quantitative expression on erythrocytes (E) of patients with systemic lupus erythematosus (SLE) was reexamined by determining the temporal stability of CR1 numbers and the frequency of a CR1 genomic restriction fragment length polymorphism (RFLP). The mean number of binding sites/(E) for Yz-1 monoclonal anti-CR1 correlated with the number of sites for polyclonal anti-CR1 that had been determined 2 to 4 yr previously in 18 normal persons (p less than 0.001), 18 patients (p less than 0.001), and 28 relatives (p less than 0.001), indicating that CR1 sites/E was a stable characteristic in all three groups. The mean number of Yz-1 sites/E was 281 +/- 34 (+/- SEM) in 28 probands with SLE and 457 +/- 21 in 93 relatives, both determinations being less than that for 100 normal persons, 553 +/- 21 (p less than 0.002). Thirty-six patients and 51 normal individuals were also assessed for the presence of the 7.4 kb and 6.9 kb HindIII CR1 allelic restriction fragments that correlate with high and low expression, respectively, of CR1 on E. The distribution of patients differed from normal (p less than 0.05), with a smaller proportion being homozygous for the 7.4 kb allele. In addition, the mean numbers of Yz-1 sites/E for patients and relatives who were homozygous (p less than 0.02) and heterozygous (p less than 0.05) for the 7.4 kb allele were significantly lower than those for normal persons matched for the HindIII RFLP, suggesting the existence of additional heritable factors that decrease CR1 expression. The stability over time of the CR1 deficiency among patients, the finding of decreased CR1 number among an expanded group of relatives, the altered frequency among patients of CR1 alleles defined by the HindIII RFLP, and the decreased expression of CR1 on E among patients and relatives compared with normal individuals having the same HindIII RFLP indicate a role for genetic factors in CR1 deficiency in SLE.
Antigen presentation by hapten-specific B lymphocytes. IV. Comparative ability of B cells to present specific antigen and anti-immunoglobulin antibody.
Authors: Lichtman A H , Tony H P , Parker D C , Abbas A K 
Published: December 2022

Abstract
The ability of trinitrophenyl (TNP)-binding murine B lymphocytes to present native rabbit IgG (RGG), TNP-modified RGG, and rabbit anti-mouse Ig (RAMG) to an Ia-restricted, RGG-specific helper/inducer T cell clone was compared. By three independent assays (lymphokine secretion, T cell proliferation, and B cell differentiation), TNP-RGG was presented at 10(2)- to 10(3)-fold lower concentrations than RGG, and RAMG at 10(2)- to 10(3)-fold lower concentrations than TNP-RGG. The available data suggest that the efficiency of antigen presentation is dependent primarily on the avidity of binding of a ligand to B cell surface Ig and/or the extent of subsequent endocytosis (modulation). Despite the observed quantitative differences between anti-Ig (RAMG) and specific antigen (TNP-RGG), these results demonstrate that qualitatively both are essentially similar in their ability to mediate specific T-B interactions. Thus, anti-Ig antibodies are valid models for analyzing cognate interactions between antigen-specific B and helper T lymphocytes.
T3-T cell receptor (Ti) complex-independent activation of T cells by wheat germ agglutinin.
Authors: Yachie A , Hernandez D , Blaese R M 
Published: December 2022

Abstract
The T3-Ti complex appears to play a central role in the activation of T cells by antigens and mitogens. Wheat germ agglutinin (WGA) is a unique lectin which inhibits T cell proliferation induced by mitogens, but it also induces marked IL 2 production by peripheral blood T cells. The pattern of responses induced by WGA suggests that this lectin may use a different mechanism of T cell activation other than the mechanism employed by the common T cell stimulants. We first investigated the production of IL 2 by Jurkat cells (E6-1) stimulated with WGA, before and after modulation of the surface T3-Ti complex. IL 2 production was markedly reduced after modulation of the T3 antigen from the cell surface when these cells were stimulated with PHA. In contrast, little change was observed in WGA-induced IL 2 production after modulation. Furthermore, we examined the effect of WGA on a T3-mutant of E6-1 cells (T3.1) which does not produce IL 2 in response to PHA or PHA plus PMA. WGA-stimulated T3.1 cells produced a significant amount of IL 2 with or without added PMA. In addition, a small but consistent rise in intracytoplasmic free calcium was observed when these cells were stimulated with WGA. These results demonstrate the presence of an alternative mechanism of T cell activation independent of the T3-Ti complex.
Human Fc gamma receptors: stable inter-donor variation in quantitative expression on platelets correlates with functional responses.
Authors: Rosenfeld S I , Ryan D H , Looney R J , Anderson C L , Abraham G N , Leddy J P 
Published: December 2022

Abstract
Evidence has recently been presented that a 40,000 dalton membrane sialoglycoprotein (p40) shared by monocytes and granulocytes serves as the human platelet receptor for aggregated IgG. We now report that the platelets of normal donors exhibit stable quantitative differences in the expression of this receptor molecule, as determined by flow cytometry using fluorescent staining with murine monoclonal antibody to p40 (mab IV.3). These inter-donor differences were reproducible on repeated testing over at least 4 mo. In concurrent assays, the binding of mab IV.3 to each donor's platelets was highly correlated with the binding of heat-aggregated human IgG, also assayed by flow cytometry. The biological relevance of this quantitative variation in IV.3 binding is suggested by its reproducible correlation with platelet responsiveness to aggregated IgG measured by aggregometry. Such stable quantitative variation in platelet Fc receptor expression among individual humans could contribute to differences in severity of certain pathologic processes initiated by IgG-containing immune complexes.
Class-specific regulation of anti-DNA antibody synthesis and the age-associated changes in (NZB x NZW)F1 hybrid mice.
Authors: Sekigawa I , Okada T , Noguchi K , Ueda G , Hirose S , Sato H , Shirai T 
Published: December 2022

Abstract
Investigations of regulatory helper and suppressor T cells in the in vitro anti-DNA antibody synthesis in NZB x NZW (B/W) F1 hybrid mice were initiated by the development of an in vitro system in which G10-passed B cells from B/W F1 mice were cocultured with mitomycin C-treated T cells in the presence of Con A and either in the presence or in the absence of LPS. It was revealed that each IgG and IgM anti-DNA antibody synthesis was under the regulation of separate L3T4+ helper and Ly-2+ suppressor T cells. The function of these class-specific regulatory T cells was age-dependent. Although the helper effect of L3T4+ T cells on IgG antibody synthesis increased, the effect of L3T4+ T cells on IgM antibody production decreased in B/W F1 mice with aging. The IgG anti-DNA antibody production in the cocultures of L3T4+ T cells and B cells was suppressed by addition of Ly-2+ T cells from young but not aged B/W F1 mice, whereas the production of IgM anti-DNA antibodies was suppressed by Ly-2+ T cells from aged but not young B/W F1 mice. We also found that although IgM anti-DNA antibody-producing B cells were already present in 2-mo-old mice, B cells producing IgG antibodies under the influence of L3T4+ T cells appeared in mice at 7 mo of age. These data clearly indicate that separate class-specific regulatory T cells are involved in the production of IgM and IgG anti-DNA antibodies and that the total serum level of the antibodies is reflected by both their age-associated changes and the generation of antibody-forming B cells in B/W F1 mice.
The interleukin 1 receptor. Dynamics of interleukin 1 binding and internalization in T cells and fibroblasts.
Authors: Mizel S B , Kilian P L , Lewis J C , Paganelli K A , Chizzonite R A 
Published: December 2022

Abstract
In this study, we have demonstrated that a murine T cell lymphoma, EL 4, and a murine fibroblast cell line, Swiss 3T3, possess a single class of high affinity interleukin 1 (IL 1) receptors that exist in a dynamic state of equilibrium that is influenced by IL 1. In the absence of IL 1, the IL 1 receptor appears to turnover with a t1/2 of approximately 11 hr. However, when cells are incubated in the presence of IL 1, the IL 1 receptor undergoes extensive ligand-induced down-regulation. IL 1 itself is internalized at 37 degrees C; 50% of the surface-bound IL 1 is internalized in 60 to 120 min. IL 1 does not undergo degradation for at least 6 hr after internalization. By using electron microscopy and autoradiography, we observed several important features of the internalization process. When cells having bound 125I-IL 1 at 4 degrees C were shifted to 37 degrees C, IL 1 moved from the cell membrane to the cytoplasm where it was found in proximity to nuclei or within lysosomes. IL 1 appeared to progressively accumulate in nuclei. Six hours after shifting cells to 37 degrees C, 30 to 35% of the internalized 125I-IL 1 is associated with the cell nucleus. The accumulation of relatively high levels of IL 1 in the nucleus raises the interesting possibility that IL 1 may not only interact in a highly specific manner with cell surface receptors, but also with potentially important nuclear receptors.
Purification and biochemical characterization of a human autocrine growth factor produced by Epstein-Barr virus-transformed B cells.
Authors: Buck J , Hämmerling U , Hoffmann M K , Levi E , Welte K 
Published: December 2022

Abstract
Autocrine growth factor for Epstein-Barr virus-transformed human B cells (aBGF), a protein that is constitutively produced by the human EBV-transformed B cell line 5/2, has been purified from serum-free conditioned medium. The purification involved sequential ammonium sulfate precipitation, ion exchange chromatography, gel filtration, and reversed-phase high performance liquid chromatography. The purified protein has a m.w. of 16,000 in NaDodSO4/polyacrylamide gel electrophoresis and an isoelectric point between 7.0 and 8.0. The relative molecular mass 16,000 form exists in equilibrium with dimeric and tetrameric forms. aBGF supports the growth of EBV-transformed B cells, which have been deprived of their own conditioned medium. The purified aBGF is fully effective at 0.5 ng/ml and has no interleukin 1 activity in the lymphocyte activation factor assay. Because several randomly selected lines of EBV-transformed cells and one EBV-negative lymphoma cell line both produce aBGF activity and show growth dependency on aBGF and because stimulation of normal B cells with anti-immunoglobulin M is increased by aBGF, we propose that aBGF has general significance for growth control of human B cells.
cDNA cloning and sequencing reveals that the electrophoretically constant DR beta 2 molecules, as well as the variable DR beta 1 molecules, from HLA-DR2 subtypes have different amino acid sequences including a hypervariable region for a functionally important epitope.
Authors: Wu S K , Yabe T , Madden M , Saunders T L , Bach F H 
Published: December 2022

Abstract
Two-dimensional gel electrophoresis (2D-PAGE) of DR molecules from three different Dw subtypes (Dw2, Dw12, and FJO) of the HLA-DR2 haplotype reveals that at least two DR beta genes are expressed. Protein mixing experiments demonstrate that one of the two expressed DR beta molecules is electrophoretically variable (referred to as DR beta 1), and the other (DR beta 2) migrates constantly among DR2 subtypes. We have constructed cDNA libraries from Dw12 and FJO homozygous typing cells (HTC DHO for Dw12 and HTC FJO for FJO) and isolated DR beta cDNA clones. Four of these clones (FJO-13, DHO-8, FJO-6, and DHO-7) were sequenced, and the deduced amino acid sequences were compared with each other and with two published amino acid sequences for the DR beta molecules derived from a DR2-Dw2HTC. Prediction of the migration patterns on 2D-PAGE from the amino acid sequences of these and other DR beta molecules allows the tentative designation of the two full-length cDNA (DHO-8 and FJO-13) as coding for DR beta 2 molecules and the other two cDNA (DHO-7 and FJO-6) for DR beta 1 molecules. Amino acid sequence comparisons also show that the constantly migrating DR beta 2 molecules, as well as the electrophoretically variable DR beta 1 molecules, from Dw2, Dw12, and FJO have different primary amino acid sequences, including a clustered difference in the third hypervariable region of the polymorphic first domain.
Production and characterization of a monoclonal antibody specific for the human lymphocyte low affinity receptor for IgE: CD 23 is a low affinity receptor for IgE.
Authors: Bonnefoy J Y , Aubry J P , Peronne C , Wijdenes J , Banchereau J 
Published: December 2022

Abstract
In the present study a gamma 1 kappa monoclonal antibody, Mab 25, specific for the receptor for the Fc fragment of IgE on lymphocytes (Fc epsilon RL) was established. This antibody was generated after fusion of spleen cells from mice immunized with the EBV-transformed lymphoblastoid cell line RPMI 8866, which is known to express Fc epsilon RL at high density. Mab 25 inhibits strongly the binding of IgE to RPMI 8866 cells and to other Fc epsilon RL-positive EBV-transformed lymphoblastoid cell lines. A 50% inhibition of IgE binding was observed at a Mab 25 concentration of 10 ng/ml. The binding of IgE was also inhibited by Fab fragments of Mab 25, suggesting that the inhibition is not simply due to steric hindrance or to an eventual binding through its Fc portion. Mab 25 only binds to cell lines expressing Fc epsilon RL. Mab 25 immunoprecipitated a single polypeptide with an apparent m.w. of 42 Kd, pI 4.9. The membrane molecule bound to and eluted from a Mab 25 immunoabsorbent had the same apparent m.w. and pI as the Fc epsilon RL purified from an IgE immunoabsorbent. Additionally, when RPMI 8866 cell lysates were cleared with Mab 25, no Fc epsilon RL could be bound to or eluted from an IgE immunoabsorbent. Mab 25 was found to weakly bind to a minor proportion of blood (1 to 4%), tonsil (2 to 9%) and spleen (4 to 5%) mononuclear cells with a low intensity. By double fluorescence analysis, most of the Fc epsilon RL-positive cells were found to be CD 20-positive B lymphocytes. The staining pattern of Mab 25 and the biochemical characteristics of the antigen detected by Mab 25 were comparable to those of the CD 23 Mab. The four CD 23 Mab MHM 6, PL 13, HD 50, and Tü 1 were found to inhibit the binding of IgE. PL 13 was found to totally inhibit the binding of Mab 25 to RPMI 8866 cells, whereas Tü 1 and MHM 6 only partially inhibited Mab 25 binding. HD 50 was unable to block the binding of Mab 25. The finding that different CD 23/Fc epsilon RL-specific monoclonal antibodies recognizing distinct epitopes have in common the capacity of inhibiting the binding of IgE suggests that upon binding they induce a conformational alteration of the Fc epsilon RL resulting in a loss of the IgE binding capacity. In conclusion, our data demonstrate that the CD 23 antigen is a low affinity receptor for IgE on lymphocytes.
Human large granular lymphocytes express high affinity receptors for murine monoclonal antibodies of the IgG3 subclass.
Authors: Anasetti C , Martin P J , Morishita Y , Badger C C , Bernstein I D , Hansen J A 
Published: December 2022

Abstract
We have evaluated the ability of murine monoclonal antibodies to mediate antibody-dependent cell-mediated cytotoxicity (ADCC) by human lymphoid cells. Purified large granular lymphocytes (LGL) and interleukin 2-dependent cloned LGL lines having a CD2+/CD16+/CD3- phenotype were tested as effector cells in an ADCC assay by using a family of IgG isotype switch variant anti-Thy-1.1 antibodies against 51Cr-labeled Thy-1.1+ murine SL2 thymoma target cells, a system in which human cells have no spontaneous cytotoxicity. Cytotoxicity was greatest when using the IgG3, followed in rank order by the IgG2a and IgG2b. No cytotoxicity was observed with the IgG1 antibody. Because the antigen-binding regions of the antibodies are identical, the differences in cytotoxicity directly reflect the relative affinity of LGL Fc receptors for each antibody isotype.
In vivo activation of quiescent B cells by anti-immunoglobulin. I. Induction of latent VH allotype production in adult rabbits by treatment with heterologous antibodies or antibody fragments.
Authors: Metzger D W , Fried V A , Van Cleave V H 
Published: December 2022

Abstract
We demonstrated previously that injection of adult rabbits with homologous anti-VHa1 allotype antibody induces the appearance in serum of genetically unexpected (latent) a1 immunoglobulin (Ig) and a1-like internal images. We have now investigated the mechanism for this induction effect and have found that treatment of animals with polyclonal goat or monoclonal mouse anti-a1 antibody similarly results in production of unexpected a1 determinants. The N-terminal amino acid sequences of deblocked heavy chains showed that latent a1 Ig induced by monoclonal antibody treatment was identical to nominal a1 Ig at 18 of 19 residues, with the one amino acid difference at position 13 probably due to a single nucleotide change. Like nominal a1, these molecules expressed multiple VHa1 framework epitopes, as demonstrated by direct immunoelectron microscopic visualization of immune complexes. Whereas F(ab)'2 fragments of rabbit anti-a1 antibody retained inducing activity, F(ab) fragments were effective only when administered in an aggregated form; this result suggests that cross-linking of surface Ig receptors plays a critical role in the induction process. We conclude that all rabbits contain dormant B cells expressing germ-line-encoded latent allotypes, and that in vivo administration of anti-Ig antibody causes activation of these cells directly rather than through perturbation of an allotype regulatory network.
A high m.w. form of decay-accelerating factor (DAF-2) exhibits size abnormalities in paroxysmal nocturnal hemoglobinuria erythrocytes.
Authors: Kinoshita T , Rosenfeld S I , Nussenzweig V 
Published: December 2022

Abstract
Decay-accelerating factor (DAF) is a 70,000 Mr membrane protein that inhibits the amplification of the complement cascade on cell surfaces. Monoclonal antibodies against different epitopes of the 70,000 Mr DAF (DAF-1) recognize a second band at the position of 140,000 Mr on a Western blot of total red cell ghost proteins or partially pure DAF subjected to electrophoresis under denaturing conditions. Like DAF-1, this polypeptide (DAF-2) has the ability to accelerate decay of the C3 convertase, C4b2a, and to reincorporate into red cell membranes. A population of erythrocytes from patients with paroxysmal nocturnal hemoglobinuria (PNH) lack DAF-1 and also DAF-2. In addition, in some patients' red cells bearing DAF-1 of normal Mr, DAF-2 is 5,000 to 10,000 Mr smaller than normal. The structural basis for these differences in size of DAF and its PNH variants is unknown.
Monoclonal antibodies specific to the alpha-subunit of the mast cell's Fc epsilon R block IgE binding and trigger histamine release.
Authors: Baniyash M , Alkalay I , Eshhar Z 
Published: December 2022

Abstract
In an attempt to block the interactions between IgE and its receptor on mast cells (Fc epsilon R), we have established anti-Fc epsilon R monoclonal antibodies (mAb) by fusion of myeloma cells with mouse splenocytes immunized with irradiated rat basophilic leukemia (RBL) cells. Two anti-Fc epsilon R mAb were obtained (denoted 4.7 and 5.14) that could specifically bind to RBL and mast cells. This binding could be inhibited by IgE. The mAb and their F(ab')2 fragments inhibited 125I-IgE binding to RBL cell and triggered cell degranulation. The Fab' fragments, on the other hand, could only inhibit IgE binding but did not stimulate cell degranulation. Furthermore, these monovalent fragments inhibited RBL and mast cell degranulation induced by IgE-antigen complexes both in vitro and in vivo in the passive cutaneous anaphylaxis reaction. The number of mAb 4.7 and 5.14 molecules bound per RBL cells was similar to that of IgE; nevertheless, mAb 4.7 and 5.14 recognized different epitopes on the IgE receptor. Immunoprecipitation and immunoblotting analysis demonstrated that the mAb reacted with the alpha-subunit of the Fc epsilon R. Our findings establish the anti-Fc epsilon R mAb as a useful reagent for the isolation and characterization of the Fc epsilon R's alpha-subunit and the monomeric (Fab') for blocking the IgE-Fc epsilon R interactions.
Interaction between cytokines and 8-mercaptoguanosine in humoral immunity: synergy with interferon.
Authors: Goodman M G 
Published: December 2022

Abstract
In previous studies it has been demonstrated that a T cell-like differentiation signal is transmitted by C8-substituted guanine ribonucleosides such as 8-mercaptoguanosine (8MGuo) to antigen-stimulated B cells. A large subset of potentially reactive B cells remains unresponsive to antigen even in the presence of signals provided by these nucleosides except when this signal is preceded by a soluble activity present in mixed lymphocyte culture supernatants. Studies with purified preparations of interleukin (IL)-1, IL-2, IL-3, granulocyte-macrophage colony stimulating factor, B cell stimulatory factor 1 (IL-4), and B cell growth factor II (IL-5) indicated that none of these activities is capable of synergizing with 8MGuo to augment B cell responsiveness to antigen. Therefore, supernatants from a number of cloned cell lines were examined for activity that could synergize with 8MGuo, in order to determine the cellular source of this activity. Soluble products secreted by cloned 24/G1 T cells act synergistically with 8MGuo to evoke enhanced antibody responses to specific antigen in populations of purified B cells. Because concanavalin (Con) A-activated 24/G1 cells produce large quantities of interferon-gamma (IFN-gamma), the possibility that interferons might mediate synergy with 8MGuo was investigated. Purified murine IFN-gamma is unable to interact synergistically with 8MGuo; moreover, treatment of active 24/G1 supernatants with monoclonal anti-IFN-gamma antibodies or at pH 2 fails to abrogate their ability to synergize. In contrast to IFN-gamma, when B cells were supplemented with either IFN-alpha or IFN-beta, antigen-dependent synergy with 8MGuo was observed. However, abrogation of IFN-alpha and IFN-beta activity with specific antibodies fails to interfere with synergy between 8MGuo and mixed lymphocyte culture or Con A supernatants. Therefore, it appears that although IFN-alpha and IFN-beta are not responsible for the synergizing activity present in activated T cell supernatants, they nonetheless represent a previously unrecognized source of synergizing activity.