bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monoclonal antibodies for carcinoembryonic antigen and related antigens as a model system: determination of affinities and specificities of monoclonal antibodies by using biotin-labeled antibodies and avidin as precipitating agent in a solution phase immunoassay.
Authors: Wagener C , Clark B R , Rickard K J , Shively J E 
Published: December 2022

Abstract
A general method is described for the determination of affinity constants and antigen cross-reactivities of monoclonal antibodies. The method employs biotin-labeled antibody, radiolabeled antigen, and avidin as a precipitating agent in a homogeneous phase, competitive radioimmunoassay. This method eliminates incomplete or variable precipitation of antigen-antibody complexes often encountered in immunoassays in which monoclonal antibodies are employed. Using this assay system, we were able to rapidly determine the affinity constants for a number of monoclonal antibodies elicited to carcinoembryonic antigen (CEA). In the preceding paper it was shown that five of the monoclonal antibodies recognized distinct epitopes on CEA. In antigen-binding experiments with these five monoclonal antibodies, the percent of radiolabeled CEA bound in antibody excess ranged from 30 to 92%. The CEA cross-reacting antigens, normal cross-reacting antigen (NCA), and tumor-extracted, CEA-related antigen (TEX) were significantly bound by one, and to a lesser degree, by two of the five antibodies. Two antibodies did not bind significant amounts of NCA or TEX. In inhibition studies, the amount of unlabeled CEA leading to 50% inhibition of 125I-labeled CEA-binding was in the range of 3.7 to 760 ng per tube. The amount of TEX showing the same degree of inhibition was 23-fold greater than the amount of CEA for two antibodies and 351-fold greater than the amount of CEA for a third antibody. The affinity constants for CEA were in the range of 1.0 x 10(8) to 5.1 x 10(10) M-1. The affinity constants for NCA and TEX, determined for one of the antibodies, were three orders of magnitude lower in comparison to CEA. The heterogeneity of radiolabeled CEA as indicated by the low fraction bound by one of the monoclonal antibodies is shown to be most probably an artifact resulting from radioiodination damage. The application of the approach described in this report should eliminate the problems most commonly encountered in the determination of affinity constants for monoclonal antibodies or the use of monoclonal antibodies in competitive, homogeneous-phase immunoassays.
Monoclonal antibodies for carcinoembryonic antigen and related antigens as a model system: a systematic approach for the determination of epitope specificities of monoclonal antibodies.
Authors: Wagener C , Yang Y H , Crawford F G , Shively J E 
Published: December 2022

Abstract
A systematic approach for the determination of epitope specificities of monoclonal antibodies to a complex antigen system is described. After initial screening to identify antigen-binding monoclonal antibodies, one or more of the clones are isolated by limiting dilution cloning, grown in ascites, and the resulting antibodies secreted into the ascitic fluid are affinity purified on Sepharose-bound protein A, radiolabeled, and cross-compared with antibodies from other clones by a solid-phase competitive immunoassay. In this work, BALB/c mice were immunized with either purified carcinoembryonic antigen (CEA) or the CEA-producing cell line HC 84S. Spleen cells were fused with the mouse myeloma cell line Sp2/0-Ag14. The supernatants from 25 hybrids showed a significant binding of 125I-CEA (greater than or equal to 15%). Nine hybrids were cloned, resulting in 33 different clones. The antibodies produced by the different cloned hybrids and the remaining uncloned hybrids recognized a total of five different epitopes on CEA. All of the epitopes reside on the protein moiety of the molecule as determined by antibody binding to deglycosylated CEA. The monoclonal antibodies with five different epitope specificities were reacted with tissue sections of normal and cancerous tissues and with peripheral blood smears. Each of the five monoclonal antibodies reacted with tissue sections from colonic, gastric, lung, and mammary carcinomas, as well as from a benign colonic polyp and a resection margin from a colonic carcinoma. Four monoclonals reacted with normal liver tissue. Granulocytes in peripheral blood smears bound three antibodies strongly and one antibody weakly, and one antibody was not bound. One monoclonal antibody that reacted with normal liver tissue was not bound by granulocytes. The ability of these five monoclonal antibodies to differentially detect three different CEA-related antigens in normal and malignant tissues may have clinical utility.
Use of monoclonal anti-gp70 antibodies to mimic the effects of the Rfv-3 gene in mice with Friend virus-induced leukemia.
Authors: Britt W J , Chesebro B 
Published: December 2022

Abstract
During the course of progressive Friend virus-induced leukemia in Rfv-3r/s mice, antiviral antibody caused a marked reduction in the frequency of leukemic spleen cells releasing infectious virus. We investigated the mechanism of this antibody-induced alteration of leukemia cell phenotype in a series of passive transfer experiments using monoclonal antiviral antibodies. Our results indicated that two IgG2a anti-gp70 cytotoxic antibodies could reduce the frequency of virus-producing cells within the leukemic spleen as well as maintain the virus-nonproducing phenotype once it was established. IgG2a and IgG2b monoclonal anti-p 15 antibodies, IgM, and IgA anti-gp70 antibodies, and an IgG3 anti-p 15(E) antibody were not effective. The mechanism of this phenotypic alteration appeared to involve an antibody-mediated cytostasis of virus-producing leukemia cells with the subsequent over-growth of virus-nonproducing cells. The maintenance of the virus-nonproducing phenotype was dependent on the presence of anti-gp70 antibodies capable of neutralizing and clearing infectious F-MuLV in vivo. The presence of these neutralizing antibodies appeared to prevent reinfection of virus-nonproducing cells and therefore interfered with reversion to the virus-producing phenotype.
Ten percent of normal B cells and plasma cells share A VH determinant(s) (J606-GAC) with a distinct subset of murine VHIII plasmacytomas.
Authors: Basta P , Kubagawa H , Kearney J F , Briles D E 
Published: December 2022

Abstract
Our findings indicate that a subset of VHIII antibodies, which we refer to as J606-GAC, contains a determinant(s) that is present on 5 to 15% of normal splenic B cells and plasma cells as detected by immunofluorescence. This subpopulation is detected by purified antibody, 0-1, which was prepared against a murine anti-group A carbohydrate (anti-GAC) hybridoma antibody. The J606-GAC subset includes the beta 2, 1 fructosan myelomas J606, EPC109, W3082, ABPC4, and UPC61, as well as 13 anti-GAC hybridomas. The 0-1 antiserum failed to react with hybridoma and myeloma immunoglobulins from murine VH groups I and II or other VHIII antibodies. By Western blot analysis, it was observed to react with isolated heavy, but not light, chains of J606-GAC-bearing antibodies. 0-1 failed to react with myelomas XRPC44 and J539, which have the same J region as J606 but a very different VH region. These observations indicate that 0-1 is detecting a VH region determinant. The J606-GAC marker recognized by 0-1 was expressed as early as 4 days after birth and was expressed at similar frequencies in germfree and conventional mice. Immunoprecipitation of both surface and biosynthetically labeled proteins from spleen cells or J606-GAC-positive hybridoma cell lines, respectively, confirmed that 0-1 was recognizing an immunoglobulin determinant.
Sezary syndrome. I. Specific skin-directed migration of peripheral blood lymphocytes.
Authors: Laroche L , Papiernik M , Bach J F 
Published: December 2022

Abstract
The in vitro migration of peripheral blood lymphocytes (PBL) from Sezary syndrome (SS) patients and from controls was studied using a migration assay under agar. Only PBL from SS patients migrate to normal allogeneic skin. This migration is organ specific. It requires the integrity of lymphocyte membrane receptors. Serum factors are not involved. Studies of the nature of these migrating lymphocytes using monoclonal antibodies suggest that they belong to a subset of helper T cells. These data indicate a functional impairment of SS lymphocytes, which enables them to respond to a skin-derived signal.
Proliferating and helper T lymphocytes display distinct fine specificities in response to human fibrinopeptide B.
Authors: Peterson L B , Wilner G D , Thomas D W 
Published: December 2022

Abstract
The fine specificity of T cell responses involved in the generation of help for antibody production and proliferation was examined by using the 14 amino acid peptide human fibrinopeptide B (hFPB, B beta 1-14) and its synthetic peptide homologues B beta 1-14(Lys14), B beta 1-13, and B beta 3-14. Peritoneal exudate or lymph node T cells from C57BL/10 and B10.BR mice immunized with hFPB or its synthetic homologues were used to measure in vitro proliferative responses. T cells from hFPB-immunized B10.BR mice showed specific proliferation to hFPB, but were unresponsive to B beta 1-14(Lys14), B beta 1-13, and B beta 3-14. B10.BR mice immunized with B beta 1-14(Lys14), B beta 1-13, or B beta 3-14 were unresponsive to all peptides tested. T cells from C57BL/10 mice showed no specific proliferation after immunization and challenge with any of the peptide antigens. In contrast to the patterns of T cell proliferation, immunization of both B10.BR and C57BL/10 mice with hFPB, B beta 1-14(Lys14), B beta 1-13, or B beta 3-14 primed for significant helper T cell activity, as assessed by the augmentation of a primary in vitro B cell IgM anti-FITC plaque-forming cell response after culture with B beta 1-1(Lys14)-FITC. Significant peptide-specific helper activity was observed when the FITC moiety was conjugated to the carboxyl terminal lysine (B beta 1-14(Lys14)-FITC) as well as FITC substitution at the amino terminus (FITC-B beta 3-13 or FITC-B beta 3-14). These results suggest that the fine specificity of T cell responses to peptide antigens are different for helper and proliferating T cells and that responsiveness by one T cell subpopulation does not predict the response pattern of other functional subpopulations.
Effect of rat alveolar lining material on macrophage receptors.
Authors: Coonrod J D , Yoneda K 
Published: December 2022

Abstract
Resident alveolar macrophages of many rat strains lack detectable C receptors and cannot carry out C-mediated bacterial attachment and phagocytosis. It has not been established whether this lack of functional receptors is innate or is acquired by contact with the alveolar microenvironment. In the present studies, peritoneal macrophages treated with lavage under conditions designed to maintain viability and adherence to glass showed loss of detectability of C and Fc receptors. Depending on the concentration of lavage and the time allowed for recovery, this effect appeared to be reversible. Continued incubation of peritoneal macrophages with lavage fluid led to loss of adherence to glass and cell death. Lavage-treated 51Cr-labeled macrophages rapidly released radiolabel. Although transmission electron micrographs of lavage-treated peritoneal macrophages appeared normal, micrographs prepared with freeze-fracture techniques revealed clumping and asymmetric distribution of the intramembrane particles. Similar membrane abnormalities were present in untreated resident alveolar macrophages. The anti-receptor effect of rat lavage was not species-specific and lung lavage fluid from dogs, rabbits, and mice affected receptor detectability on rat macrophages. The anti-receptor factor in rat lavage was localized to the surfactant-containing fraction and was stable on heating at 60 degrees C. It was resistant to trypsin and partitioned into chloroform in the Bligh-Dyer extraction procedure, suggesting that it was a lipid. Purified diacyl phospholipids had no effect on macrophage receptors, but purified lysophospholipids mimicked many of the effects of surfactant. We conclude that lipids in the alveolar lining material affect alveolar macrophage membranes and receptor function.
Experimental allergic orchitis: the isolation and partial characterization of an aspermatogenic polypeptide (AP3) with an apparent sequential disease-inducing determinant(s).
Authors: Teuscher C , Wild G C , Tung K S 
Published: December 2022

Abstract
An aspermatogenic polypeptide (AP3) capable of inducing experimental allergic orchitis (EAO) in the guinea pig (GP) was purified from GP testes by sequential delipidation, acid extraction, pH precipitation, ammonium sulfate fractionation, trichloroacetic acid precipitation, gel filtration on Sephadex G-75, preparative isoelectric focusing from pH 3-10 followed by isoelectric focusing from pH 7-10, gel filtration on Sephadex G-75 Superfine under reducing conditions, and reduced acid urea gel electrophoresis. Approximately 250 micrograms (BSA equivalents) of AP3 were obtained from 500 g wet weight of GP testes. On 15% reduced acid urea polyacrylamide gels, AP3 appeared as a single band with an Rf of 0.19. SDS-PAGE showed a single band with a mobility corresponding to a m.w. of 12,500 +/- 1500. The isoelectric point, determined during purification, was 9.90 +/- 0.50. Amino acid analysis of AP3 indicates it is a protein. Gas liquid chromatographic analysis failed to reveal the presence of either hexose or hexosamine, indicating that AP3 is probably not a glycopeptide. Two to 5.0 micrograms (BSA equivalents) of AP3 are capable of inducing severe EAO in 100% of GP tested; 1 to 2.0 micrograms (BSA equivalents) induced EAO in 60% of GP tested. Because AP3 appears to be nonglycosylated and the aspermatogenic activity of AP3 is highly resistant to various denaturing conditions including reduction and alkylation, the primary sequence of the polypeptide rather than higher ordered structure may be more important in defining the determinant(s) responsible for its aspermatogenic activity.
Macrophage procoagulant activity as a measure of cell-mediated immunity in the mouse.
Authors: Geczy C L , Farram E , Moon D K , Meyer P A , McKenzie I F 
Published: December 2022

Abstract
Thioglycollate-induced peritoneal exudate cells (TG-PEC) developed increased procoagulant activity after incubation with lymphokine and lipopolysaccharide (LPS). Dilutions of up to 1/1000 for insoluble Con A and 1/200 for periodate-induced lymphokine supernatants were active in enhancing macrophage procoagulant activity (MPCA), which was detected after a 2-hr incubation period and steadily increased over 20 hr. MPCA could also be induced by antigen; peritoneal cells from sensitized B6AF1 mice with strong footpad reactions to ovalbumin (OVA) responded to as little as 0.1 microgram/ml OVA in the MPCA test in an antigen-specific manner. By contrast, PEC from sensitized CBA/J mice that gave poor in vivo responses to OVA only reacted with high concentrations of the antigen in vitro. Production of the lymphokine responsible for induction of MPCA required an Ly-1+2- T cell, a nylon wool-adherent cell, and an la-17-bearing adherent cell. The MPCA induced by lymphokine or LPS did not appear to be a serine esterase and was not inhibited by phospholipase C. Coagulation of human factor-deficient plasma with activated TG-PEC indicated a requirement for Factor X.
Suppression of ACTH-induced steroidogenesis by supernatants from LPS-treated peritoneal exudate macrophages.
Authors: Mathison J C , Schreiber R D , La Forest A C , Ulevitch R J 
Published: December 2022

Abstract
The results from a number of clinical and experimental studies have suggested that during endotoxemia, suppression of adrenocortical steroidogenesis may occur. We have examined the possibility that macrophages are the source of a factor that suppresses adrenocortical steroidogenesis. Resident and peptone-elicited peritoneal exudate macrophages (PEM) from C3HeB/FeJ mice were incubated for 4 hr at 37 degrees C in the presence or absence of T cell hybridoma-derived lymphokine (LK) that contained high concentrations of MAF activity (assessed by induction of nonspecific tumoricidal activity in PEM). The LK was removed by rinsing, and fresh medium was added, followed by Salmonella minnesota R595 LPS (final concentration 10 micrograms/ml). After 18 hr at 37 degrees C the PEM supernatants and control medium from flasks without cells were harvested and stored at -20 degrees C. Explanted rabbit adrenocortical cells in 96-well plates were exposed to 30 microliters of PEM supernatant or control medium and ACTH (10 or 100 mU/ml) in a final volume of 120 microliters for 3 consecutive days. The adrenocortical cell supernatants were harvested each day, followed by replenishment of medium, PEM supernatant, and ACTH. Fluorogenic steroid production in wells that received control medium or supernatants from PEM not treated with LPS was normal (0.22 microgram +/- 0.010 (SD) per 5 X 10(4) cells). However, as much as 75 to 95% suppression of steroidogenesis was observed in wells that received supernatants from PEM treated with LK and LPS, compared to 40% suppression in wells that received supernatant from PEM treated with LPS alone. Continued exposure (over 3 days) of adrenocortical cells to supernatants from LPS-treated PEM resulted in progressively decreasing response to ACTH. Comparable suppressive activity was observed in supernatants from LPS-treated bone marrow-derived macrophages. In further experiments, suppression was observed in wells that were pretreated (22 hr) with the appropriate PEM supernatant, and evidence was obtained that the suppressive activity was not due to carry-over LPS. Finally, results from control experiments demonstrated that suppressive PEM supernatants neither inactivate ACTH nor interfere with the assay of fluorogenic steroids. Thus, these results suggest that during endotoxemia, products from LPS-stimulated macrophages may suppress adrenocortical function.
Surface-dependent modulation by H of C5 cleavage by the cell-bound alternative pathway C5 convertase of human complement.
Authors: Fischer E , Kazatchkine M D 
Published: December 2022

Abstract
Regulation by H of formation of the C3 and C5 alternative pathway convertases of complement on cells is dependent on such chemical characteristics of the cell surfaces as their membrane content in sialic acid. Properdin-stabilized C5 convertase sites were assembled on the non-activating cells of the alternative pathway, sheep erythrocytes (Es), and on the activating cells, desialated Es and rabbit erythrocytes (Er). C5 hemolytic sites were revealed by incubation of the convertase-bearing cells with limiting C5 and excess C6-C9. H inhibited generation of C5 hemolytic sites in a dose-related fashion on Es, Er, and desialated Es at molar ratios of H/C5 of 0.03 to 0.5. H similarly inhibited C5 utilization by the cell-bound C5 convertase on Es and desialated Es regardless of the cell membrane sialic acid content; however, H was three to five times less effective on Er. Kinetic experiments also suggested that C5 hemolytic sites are generated more rapidly on Er than on Es and desialated Es. The inhibition effect of H was independent of the number of C5 convertase sites per cell on all cell types; two to three times more residual hemolytic sites were found on convertase-bearing Es that had been incubated with C5 and H as compared with cells that had been decayed by H before incubation with C5. Furthermore, H also inhibited C5 interaction with a preformed classical pathway C5 convertase. These results suggest that H interacts with C5 so as to alter C5 binding and/or cleavage by the cell-bound C5 alternative pathway convertase. Sialic acid-independent modulation by H of C5 cleavage by the C5 convertase represents an additional regulatory step in the activation of the human alternative complement pathway.
Immune responses during human schistosomiasis mansoni. X. Production and standardization of an antigen-induced mitogenic activity by peripheral blood mononuclear cells from treated, but not active cases of schistosomiasis.
Authors: Gazzinelli G , Katz N , Rocha R S , Colley D G 
Published: December 2022

Abstract
Peripheral blood mononuclear cells (PBMN) from patients with active schistosomiasis mansoni are generally induced to proliferate upon exposure to a soluble worm antigenic preparation (SWAP). In contrast, only 25% of such patients responded to SWAP exposure by the production of detectable levels of a mitogenic factor (MF) activity capable of stimulating proliferation of resting cultures of allogeneic PBMN. When former schistosomal patients (chemotherapeutically cured 10 to 40 yr previously) were tested for these two responses to SWAP, all manifested blastogenesis; 80% also responded by the production of MF activity. Only 9% of control subjects with no history of schistosomiasis produced MF activity when exposed to SWAP. The production and assay of MF activity by former schistosomiasis patients was standardized. Reliable, optimal production was achieved by using 6 X 10(6) PBMN in 2-ml cultures upon exposure to 15 micrograms protein SWAP/ml. The cells were incubated for 20 hr in the presence or absence of SWAP, at which time they were washed and recultured in fresh medium for at least 28 more hours. Subject to subject variability occurred in the optimal time of detection of MF activity in culture supernatant fluids, but detection was assured between 24 and 48 hr after the wash. The assay system for MF detection required a 5 to 7-day culture. The consistent production of MF activity by former schistosomal patients emphasized the longevity of immunologic memory to SWAP, and may indicate a post-treatment decline of immunoregulatory mechanisms that are operative in patients with active schistosome infections.
Human monoclonal antibodies to a genus-specific chlamydial antigen, produced by EBV-transformed B cells.
Authors: Rosén A , Persson K , Klein G 
Published: December 2022

Abstract
Stable B cell lines producing human monoclonal antibodies to Chlamydia were established from salpingitis patients in the early convalescence phase. The antibody-producing cells were immortalized by Epstein Barr virus (EBV) transformation. Specific antibody-secreting clones were enriched by a stepwise microtiter plate cloning procedure. The selected B cell clones showed stable antibody production for more than 1 yr in continuous culture. Serologic specificity was demonstrated by micro-immunofluorescence (micro-IF) tests against a panel of Chlamydia reference strains. The antibodies were of the IgG1 subclass, and complement fixation could be demonstrated for one clone. There was no cross-reactivity against a large number of other bacteria. The monoclonal antibodies are directed against a common genus-specific surface antigen of the Chlamydia organism. Infected McCoy cells showed a brilliant, punctuated fluorescence surrounded by an inclusion membrane. Compared with conventional antisera, the monoclonal antibodies showed a clearer fluorescence pattern with very low background.