bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antigenic variants of the nonspecific cross-reacting antigen (NCA).
Authors: Burtin P , Chavanel G , Hendrick J C , Frenoy N 
Published: December 2022

Abstract
Monoclonal antibodies (Mab) were prepared against nonspecific cross-reacting antigen (NCA) and were selected on the basis of their absence of reactivity with carcinoembryonic antigen (CEA). Four Mab were found which allowed the characterization on CEA of three epitopes, defined A, B, and C. These epitopes were all located on the peptidic moiety of this highly glycosylated antigen and were present on NCA molecules of heterogeneous m.w. (greater than 100,000, 80,000, and 48,000 m.w., the latter being the most abundant). The amount of NCA was estimated in 251 human sera both by a conventional RIA, using a rabbit antiserum, and by EIA, using different Mab: Mab 4, 18, and 33, which reacted, respectively, with epitopes A, B, and C. Each assay gave a different value of the absolute concentration of NCA in the serum. On the whole, Mab 4 gave lower values, whereas Mab 18 and 33 gave higher values as compared to RIA. Furthermore, whereas all of the human sera contained NCA which was measurable by RIA, 67 sera typed negative in EIA when using Mab 4 or 18. Eight additional sera were negative in more than one EIA. Negativity when using Mab 33 was observed in only one serum, which was also negative with Mab 4 and 18. Twenty-five of 30 sera which were negative with Mab 4 came from cancer patients, and 32 of 37 sera negative with Mab 18 came from normal subjects and noncancer patients, giving a statistically highly significant difference between the two groups of sera (p less than 0.001). Analysis of tissue perchloric extracts and NCA samples purified from these extracts gave similar results. Three extracts (one from lung, two from cancer tissue) and the corresponding NCA samples were negative with Mab 18. The discrepancies observed in these assays are best explained by assuming the existence of antigenic variants of NCA which have not been described previously. These variants appear to exist in various proportions in the different sera. The variants may represent antigenically complete and incomplete molecules. Alternatively, most of the NCA molecules may be incomplete, lacking one or another of the several NCA-specific epitopes. Sequential immunoprecipitation experiments were in favor of the second hypothesis, showing that most of the NCA molecules were incomplete, lacking either epitope A or B.
Functional and molecular analysis of three distinct HLA-DR4 beta-chains responsible for the MLR between HLA-Dw4, Dw15, and DKT2.
Authors: Hirayama K , Nishimura Y , Tsukamoto K , Sasazuki T 
Published: December 2022

Abstract
Differences in structure and function of HLA-class II molecules between HLA-DR4-related HLA-D specificities HLA-Dw4, Dw15, and DKT2 were investigated. Anti-HLA-DR framework monoclonal antibody HU-4 completely inhibited the one-way mixed lymphocyte reaction (MLR) between these specificities. HU-4 precipitated a monomorphic alpha-chain and a polymorphic beta-chain of human class II molecules from each B lymphoblastoid cell line (BLCL) homozygous for these three HLA-D specificities. We established IL 2-dependent T cell lines specific for streptococcal cell wall (SCW) antigen from peripheral blood lymphocytes (PBL) from four DR4-positive donors: an HLA-Dw4/DKT2 heterozygote, an HLA-Dw4/Dw12 heterozygote, an HLA-DKT2/D-blank heterozygote, and an HLA-Dw15/D-blank heterozygote. These T cell lines showed a proliferative response to SCW antigen in the presence of autologous or allogeneic antigen-presenting cells (APC) when T cell donors and APC donors shared at least one of the HLA-D specificities. This cooperation between the T cell line and APC was completely blocked by HU-4. We conclude from these data that the T cells could distinguish three distinct DR4 molecules expressed on APC of HLA-Dw4, Dw15, and DKT2 as restriction molecules at the presentation of SCW antigen.
Antibodies to acetylcholine receptor and tetanus toxoid: in vitro synthesis by thymic lymphocytes.
Authors: Lisak R P , Levinson A I , Zweiman B , Kornstein M J 
Published: December 2022

Abstract
Thymic lymphocytes (TL) of patients with myasthenia gravis (MG) have been reported to synthesize antibodies to acetylcholine receptors (anti-AChR). Incubation of TL with pokeweed mitogen (PWM), a polyclonal T cell- and monocyte-dependent activator of B cell differentiation, was reported to inhibit TL in vitro synthesis of anti-AChR. We studied the TL of 16 patients with MG without thymoma. TL of 10 of 16 patients synthesized anti-AChR in vitro without stimulation. In the presence of PWM, the amount of anti-AChR synthesized by the TL of these 10 patients increased in five, decreased in three, and was unaffected in two. There was a correlation between serum anti-AChR titer and PWM-stimulated synthesis (r = 0.87), but not with unstimulated synthesis (r = 0.33) of anti-AChR by TL. There was no correlation between the amount of synthesized anti-AChR and the amount of secreted IgG or with the percentage of B cells (surface Ig+) in the TL suspensions. TL of three age-matched cardiac surgery controls failed to synthesize detectable anti-AChR, although two of three synthesized IgG. Four patients with MG were booster immunized with tetanus toxoid (TT) 3 to 4 wk prior to thymectomy. TL of three synthesized anti-TT in vitro, whereas TL of three nonboosted MG patients failed to synthesize anti-TT. Thus, we have shown that TL of some patients with MG are capable of anti-AChR synthesis, with evidence of heterogeneity of the in vitro response, and the B cell repertoire in the thymus may, in part, reflect recent systemic immune events of the host.
The interaction of Escherichia coli with normal human serum: the kinetics of serum-mediated lipopolysaccharide release and its dissociation from bacterial killing.
Authors: Tesh V L , Duncan R L , Morrison D C 
Published: December 2022

Abstract
We have examined the killing of E. coli and kinetics of lipopolysaccharide (LPS) release after the exposure of the bacteria to normal human serum (NHS) and sera deficient in complement components, or with inactivated complement components. LPS of the galactose epimerase-deficient strain E. coli J5 were specifically radiolabeled by growing the bacteria in a medium containing [3H]galactose. Exposure of the washed bacteria to NHS resulted in a significant reduction (greater than 99%) in viability within 15 min and the concomitant release of radiolabeled LPS. However, maximal release of LPS was consistently 30% of the total radiolabel incorporated into the LPS molecules. The amount of tritium-labeled LPS released was shown to be directly proportional to the concentration of bacteria exposed to NHS, suggesting that release of LPS was not limited by the availability of some critical serum component(s). The consumption of complement in NHS by incubation with E. coli was demonstrated by decreased alternative and classical pathway-specific hemolytic activity. The use of Factor D-depleted and VEM-treated human sera demonstrated that, with these bacteria, both the alternative and classical pathways of complement contribute to bacterial killing and release of LPS. It is noteworthy that, in VEM-treated and Factor D-depleted sera, the rate of killing and the kinetics of LPS release were somewhat slower as compared to control serum. Bacterial killing in C7-depleted and C9-deficient human sera was minimal. Neither killing nor LPS release occurred in heat-inactivated (56 degrees C, 30 min) human serum. The amount of [3H]LPS released by C9-deficient serum was qualitatively similar to the amount released by the action of NHS. Tritium-labeled LPS was not released in C7-depleted serum. These data indicate that bacterial killing can be dissociated from LPS release, and suggest that, whereas LPS release may be necessary for the bactericidal effects of serum complement, it is probably not sufficient to effect killing. Furthermore, a significant fraction of LPS can be removed from the outer membrane of the bacteria without an apparent affect on viability.
Inhibition of lymphokine-induced macrophage microbicidal activity against Leishmania major by liposomes: characterization of the physicochemical requirements for liposome inhibition.
Authors: Gilbreath M J , Hoover D L , Alving C R , Swartz G M , Meltzer M S 
Published: December 2022

Abstract
Resident peritoneal macrophages from untreated mice develop potent microbicidal activity against amastigotes of Leishmania major after in vitro treatment with lymphokine (LK) from mitogen-stimulated spleen cells. LK-induced macrophage microbicidal activity was completely and selectively abrogated by treatment with phosphatidylcholine-phosphatidylserine (PC/PS) liposomes. Other macrophage effector functions (phagocytosis, tumoricidal activity) were unaffected, as was cytotoxicity by macrophages activated in vivo or by LK in vitro before liposome treatment. Activation factors in LK were not adsorbed or destroyed by liposomes. Liposome-induced inhibition was unaffected by indomethacin and was fully reversible: macrophages washed free of liposomes developed strong microbicidal activity with subsequent LK treatment. Changes in liposomal lipid composition markedly altered suppressive effects, but inhibition was not dependent on liposome size, cholesterol content, charge, or number of lamellae. Liposomes composed of PC alone or in combination with any of five different phospholipids were not suppressive. In contrast, inhibition was directly dependent on PS concentration within PC/PS liposomes. Phosphoserine was not inhibitory nor was dimyristoyl PS (synthetic saturated PS). However, the lysophospholipid metabolite of PS, lysoPS, was strongly suppressive. These studies suggest that the reversible and selective inhibition of LK-induced macrophage microbicidal activity by PC/PS liposomes is mediated by PS and its lysoPS metabolite.
Cellular interactions in the adoptive transfer of contact sensitivity: characterization of an antigen-nonspecific Vicia villosa-adherent T cell needed for adoptive transfer into naive recipients.
Authors: Ptak W , Green D R , Flood P 
Published: December 2022

Abstract
The adoptive transfer of delayed-type hypersensitivity (DTH) into naive recipients requires the interaction of two functionally distinct Ly-1+ T cells: and I-J- cell effector cell for DTH which transfers antigen-specific DTH only into animals whose suppressive mechanisms have been compromised, and and I-J+ cell which alone never transfers DTH but allows the transfer of DTH by the I-J- DTH effector cell into naive animals. We investigated the phenotypic and functional characteristics of the cell which "protects" the I-J- DTH effector cell from host suppressive mechanisms and allows the transfer of DTH into naive recipients. This cell was found to express the cell surface phenotype Lyt-1+,2-, L3T4+, and I-J+, and, in contrast to the I-J- DTH effector cell, was found to be adherent to the lectin Vicia villosa (VV). These cells routinely are found in the spleens of both immune or naive animals, and regardless of their origin are antigen-nonspecific in their functional activity in that they complement VV-nonadherent cells to transfer DTH responses of both TNP and oxazolone-primed cells. Treatment of recipient mice with cyclophosphamide (to remove host suppressor mechanisms) or Bordetella pertussis vaccine (which stimulates splenic T cells to circulate) abrogates the need for these cells in the transfer population, whereas treatment of donor mice with B. pertussis functionally depletes these cells from splenic T cell populations. Therefore, it appears that in the adoptive transfer of DTH responses, the antigen-specific I-J- VV-nonadherent cell requires an I-J+ VV-adherent cell in the circulation to overcome host suppressive mechanisms. The importance of these I-J+ cells in DTH responses is discussed.
Lateral diffusion of antigen receptors artificially incorporated onto B lymphocytes.
Authors: Londo T R , Peacock J S , Roess D A , Barisas B G 
Published: December 2022

Abstract
In the companion paper, we have shown that palmitate conjugates of a monoclonal anti-DNP IgA (protein 315) incorporated onto B lymphocytes can bind DNP antigens and that this binding causes polyclonal B cell activation. In this study we use fluorescence photobleaching recovery (FPR) techniques to examine the lateral diffusion and mobile fractions of antigen-receptor complexes on receptor-decorated B cells as functions of antigen concentration and epitope density. Antigens used in this study are DNP conjugates of polymerized flagellin (DNP-POL) and linear dextran of 2 X 10(6) m.w. (DNP-DEX). The diffusion coefficient observed for antigen bound to artificial receptors decreases monotonically with increased antigen dose and epitope density. When the artificial receptor-bearing cells are labeled with either relatively high concentrations of medium epitope density antigen or high epitope density antigen, a large fraction of antigen-receptor complexes become immobile in the time scale of the experiment. We attribute this behavior to extensive receptor cross-linking by antigen. In parallel with these FPR experiments, we examined the effects of antigen concentration and epitope density on the polyclonal humoral response of receptor-decorated B cells. We found that the response is a function of both antigen concentration and epitope density similar to that seen in natural B cells. The combined results of these experiments show that cell activation results when the diffusion coefficient of the antigen-receptor complex ranges between 10 X 10(-11) cm2 sec-1 and 5 X 10(-11) cm2 sec-1. These values represent threefold and sixfold decreases from the diffusion coefficient of antigen-free receptors, respectively. However, when either a high antigen concentration or epitope density causes a large fraction of antigen-receptor complexes to become immobile, B cells become unresponsive not only to the bound antigen, but also to LPS. Results obtained in this study are very similar to those obtained in a study performed with natural antigen-specific B cells. Therefore, for the responding population of receptor-decorated B cells, it is possible that antigens activate and paralyze these B cells by mechanisms similar to those by which antigens regulate normal B cell responses.
Subcellular distribution of leukotriene C4 binding units in cultured bovine aortic endothelial cells.
Authors: Chau L Y , Hoover R L , Austen K F , Lewis R A 
Published: December 2022

Abstract
The subcellular distribution of specific binding sites for [3H]leukotriene C4 ([3H]LTC4) was analyzed after sedimentation of organelles from disrupted bovine aortic endothelial cells on sucrose density gradients and was shown to be in membrane fractions I (20% sucrose) and IV (35% sucrose). Saturation binding studies of [3H]LTC4 on endothelial cell monolayers at 4 degrees C demonstrated high-affinity binding sites with a dissociation constant (Kd) of 6.8 +/- 2.2 nM (mean +/- SD) and a density of 0.12 +/- 0.02 pmol/10(6) cells. At 4 degrees C, the specific binding of [3H]LTC4 by each of the subcellular fractions reached equilibrium at 30 min and remained stable for an additional 60 min. After 30 min of incubation with [3H]LTC4, the addition of excess unlabeled LTC4 to each subcellular fraction reversed more than 70% of [3H]LTC4 binding in 10 min. The [3H]LTC4 binding activities of subcellular fractions were enhanced approximately twofold to fourfold in the presence of Ca2+, Mg2+, and Mn2+, whereas Na+, K+, and Li+ were without effect. As measured by saturation experiments, the Kd and density of LTC4 binding sites in fraction I were 4.8 +/- 1.6 nM and 16.5 +/- 1.9 pmol/mg of protein, respectively, and in fraction IV were 4.7 +/- 1.5 nM and 81.4 +/- 19 pmol/mg of protein, respectively. Inhibition of [3H]LTC4 binding in membrane-enriched subcellular fractions I and IV by LTC4 occurred with molar inhibition constant (Ki) values of 4.5 +/- 0.1 nM and 4.7 +/- 1.2 nM, respectively, whereas Ki values for LTD4 were 570 +/- 330 nM and 62.5 +/- 32.8 nM, respectively, and for LTE4 were greater than 1000 nM for each fraction; LTB4 and reduced glutathione were even less active. FPL55712, a putative antagonist of the sulfidopeptide LT components of slow reacting substance of anaphylaxis, had Ki values of 1520 +/- 800 nM and 1180 +/- 720 nM for [3H]LTC4 binding sites on membrane-enriched subcellular fractions I and IV, respectively. Thus as defined by Kd, Ki, and specificity, the LTC4 binding units that are distributed to the plasma membrane and the binding units in the subcellular fraction of greater density were similar to each other. Pretreatment of the isolated subcellular membrane fractions with trypsin abolished [3H]LTC4 binding by fraction I, enriched for the plasma membrane marker 5' nucleotidase, and that by fraction IV, enriched for the mitochondrial membrane marker succinate-cytochrome C reductase.(ABSTRACT TRUNCATED AT 400 WORDS)
Growth inhibition and cytotoxicity of tumor necrosis factor in L929 cells is enhanced by high cell density and inhibition of mRNA synthesis.
Authors: Kirstein M , Fiers W , Baglioni C 
Published: December 2022

Abstract
L929 cells were growth-inhibited after 1 to 2 days of treatment with human recombinant tumor necrosis factor (rTNF). This effect of rTNF was largely reversible, and L929 cells resumed normal growth when rTNF was removed. The rTNF showed growth inhibitory and cytotoxic activity when L929 cells approached a high cell density and grew slowly. This was shown in experiments in which L929 cells approached confluency at different times after being seeded at increasing initial densities. The rTNF had little effect on the growth of cells seeded at the lowest density tested. L929 cells cultured to high density synthesized RNA at a reduced rate. This suggested that a reduced rate of RNA synthesis may be at least in part responsible for the growth inhibitory and cytotoxic activities of rTNF on cells grown to high density. Treatment with inhibitors of RNA synthesis potentiated the cytotoxic activity of rTNF. Inhibition of mRNA synthesis was apparently responsible for the enhanced sensitivity to rTNF, as shown by experiments with 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole, an inhibitor of the synthesis of poly(A)-containing RNA.
Cells containing IgE in the intestinal mucosa of mice infected with the nematode parasite Trichinella spiralis are predominantly of a mast cell lineage.
Authors: Alizadeh H , Urban J F , Katona I M , Finkelman F D 
Published: December 2022

Abstract
To determine whether IgE+ cells in the intestinal mucosa of nematode-infected mice were of a mast cell or a lymphocyte lineage, the intestinal mucosae of mast cell-deficient w/wv mice were examined for IgE+ cells after inoculation with Trichinella spiralis muscle-stage larvae. Immunofluorescence staining techniques were used to detect IgE associated with cells in the intestinal mucosa. Comparisons were made among four strains of mice, w/wv (mast cell-deficient), +/+ (normal congenic littermates of w/wv), BALB/c, and SJL, that were either uninfected controls or inoculated with T. spiralis. Tissue sections from the small intestine of T. spiralis-infected BALB/c, SJL, and +/+ mice were fixed in ethanol and were stained with an affinity-purified F(ab')2 rabbit anti-mouse IgE followed by FITC goat anti-rabbit IgG. Large numbers of cells in the intestinal mucosa exhibited bright fluorescence. When other sections of intestines from these mice were processed in Carnoy's fixative and were stained with alcian blue at low pH (a metachromatic stain for mast cells) or alcian blue followed by immunofluorescence staining for IgE, large numbers of mast cells were observed in the intestinal mucosa, and 70 to 90% stained positively for IgE. There was a considerable number of cells in the intestinal mucosa which were IgE+ but which did not stain with alcian blue. Few alcian blue-positive cells and no IgE+ staining cells were present in the intestinal mucosa of control, uninfected +/+, BALB/c, and SJL mice. To determine whether these IgE+ alcian blue-negative cells were of a lymphocyte or a mast cell lineage, the mast cell-deficient w/wv mouse strain was examined after infection with T. spiralis. In contrast to BALB/c, SJL, or +/+ mice, few cells in the intestinal mucosa of T. spiralis-infected w/wv mice stained with alcian blue or were positive for IgE. However, when the IgE response in the MLN of the w/wv mice was compared to the IgE response of BALB/c, SJL, and +/+ mice, numerous IgE+ cells, but no alcian blue-positive cells, were observed in the parenchyma of the MLN from all four strains of T. spiralis-infected mice. In addition, flow microfluorometric analysis of MLN cells stained for surface IgE in suspension showed a comparable proportion of IgE-bearing cells, which were mostly B lymphocytes, among all four strains of T. spiralis-infected mice.(ABSTRACT TRUNCATED AT 400 WORDS)
Molecular cloning of the cDNA encoding the T3 gamma subunit of the mouse T3/T cell antigen receptor complex.
Authors: Krissansen G W , Owen M J , Fink P J , Crumpton M J 
Published: December 2022

Abstract
Complementary DNA (cDNA) clones encoding the T3 gamma subunit of the mouse T3/T cell antigen receptor complex were isolated from a cDNA library prepared from a cytochrome C-specific, I-E (class II antigen)-restricted murine T cell clone. The cDNA hybridized to a single mRNA transcript of 1 kb in size the expression of which was restricted to T lymphocytes. The 182-amino acid sequence deduced from the cDNA revealed a signal peptide, a 89-amino acid extracellular domain with one N-glycosylation site, a hydrophobic domain with a centrally located glutamic acid residue, and a 44-amino acid intracellular domain. Comparative analysis of the mouse T3 gamma sequence with those of the human T3 gamma chain and the related human and mouse T3 delta chains revealed that the regions incorporating the extracellular cysteine residues were highly conserved. More importantly, the mouse T3 gamma subunit retained the potential serine phosphorylation site (Ser 126) unique to the human T3 gamma subunit, in the membrane-proximal region of the intracellular domain. The 16-amino acid region flanking Ser 126 was totally conserved (100%) in the gamma subunits, yet showed little homology (38 to 44%) with the corresponding region in the delta subunits, in spite of the otherwise high degree of conservation (61 to 68%) between the remainder of the cytoplasmic domains of the gamma and delta chains.