bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antibodies to double-stranded DNA: purification and characterization of binding specificities.
Authors: Gilliam A C , Lang D , LoSpalluto J J 
Published: December 2022

Abstract
Antibodies to double-stranded DNA are found almost exclusively in serum of patients with the autoimmune disease systemic lupus erythematosus (SLE). Very little is known about the nature of the antibody binding site(s) on DNA. We report here the affinity purification from SLE serum of a group of IgG and IgM antibodies that bind in nitrocellulose filter binding assays to entirely double-stranded radiolabeled DNA devoid of single-stranded regions. We have studied the specificities of these purified antibodies by competition with various unlabeled polynucleotides and have visualized their binding to double-stranded DNA by electron microscopy. From the competition studies we could identify a type of purified antibody that binds only to entirely double-stranded DNA and other types that bind to both double- and single-stranded DNA. We report also that purified antibodies that bind to double-stranded poly d(AT) bind well to single-stranded DNA. They appear to be different from those purified antibodies that bind to native double-stranded DNA; antibodies to poly d(AT) can be shown to bind independently of antibodies to native double-stranded DNA. Our results suggest that a heterogeneous group of antibodies to double-stranded DNA can exist in a single SLE serum.
Antibody-dependent cell-mediated cytolysis (ADCC) with antibody-coated effectors: new methods for enhancing antibody binding and cytolysis.
Authors: Jones J F , Segal D M 
Published: December 2022

Abstract
When P388D1 cells are incubated with anti-TNP IgG antibody and centrifuged through a mixture of dibutylphthalate and bis-(2-ethylhexyl)phthalate (1.5:1), large amounts of antibody remain cell bound for at least 20 hr after washing. Incubating cells with antibody in various concentrations of polyethylene glycol also enhances antibody binding compared with control cells incubated with antibody alone. P388D1 cells coated with anti-TNP antibody are potent killers of TNP-conjugated chicken erythrocytes (not coated with antibody). The cytolytic activity increases in proportion to the amount of antibody bound by the effector cells. Lysis is antibody dependent and hapten inhibitable. When mediated by antibody-coated effectors, lysis is less suceptible to inhibition by aggregated IgG than lysis of antibody-coated cells mediated by untreated effector cells.
Characterization of an auto-rosette inhibitory fraction in mouse serum.
Authors: Hsu K H , Ghanta V K , Duncan L A , Hunt C E , Hiramoto R N 
Published: December 2022

Abstract
Normal mouse sera inhibited auto-erythrocyte rosette formation by mouse thymus cells. Serum inhibitory factor was associated with high density lipoprotein (HDL) isolated from mouse sera with sequential flotation ultra-centrifugation techniques. Other portions of normal mouse sera, i.e., very low density lipoprotein (VLDL), low density lipoprotein (LDL), lipoprotein-free serum, and delipidated HDL had little or no inhibitory activity. A 20-fold purification with 68% recovery of total serum activity was obtained by this isolation procedure. HDL from the serum of BALB/c, C57BL/6, C3H, and NZB/BIN mice inhibited BALB/c auto-rosettes. Inhibition was observed when lymphocytes were preincubated with HDL and then washed before assaying, but there was no inhibition when erythrocytes were pretreated.
Production of lymphocyte-activating factor (Interleukin 1) by macrophages activated with colony-stimulating factors.
Authors: Moore R N , Oppenheim J J , Farrar J J , Carter C S , Waheed A , Shadduck R K 
Published: December 2022

Abstract
Murine peritoneal exudate macrophages incubated with medium conditioned by L929 cells were stimulated to produce lymphocyte-activating factor (LAF, Interleukin 1). This stimulatory activity was partially neutralized by antiserum prepared against partially purified L cell colony-stimulating factor (CSF) and comigrated upon gel filtration with the myeloproliferative activity. LAF-inducing activity of three different L cell CSF preparations, including one purified to homogeneity, was dependent upon the concentration of CSF. A minimum of 1,000 to 3,000 units of CSF activity was required to stimulate macrophagfes to produce LAF. Concanavalin A (Con A) stimulated splenic supernatants also contained CSF and LAF-inducing activities that co-eluted upon gel filtration. LAF-inducing activities co-eluting with the two Con A CSF peaks (apparent m.w. of 25,000 and 35,000) were effective at minimum dilutions containing 1,000 to 3,000 units of CSF activity correlating in potency with L cell-derived CSF. Based on these data, it is proposed that CSF, whether of L cell or lymphoid origin, not only has myeloproliferative activities but also is capable of stimulating macrophages to produce LAF.
Oscillations of IgM antibody affinity at the level of single immunocytes.
Authors: Pini C , Di Felice G , Neri R , Mancini C , Vicari G , Doria G 
Published: December 2022

Abstract
IgM antibody affinity was measured by hemolytic plaque inhibition assays on spleen cells from mice immunized with a single injection of DNP-dextran. Maturation of affinity was found to occur with time after 1 to 1000 microgram of immunogen and to be characterized by rapid oscillations independent from changes inFC number/spleen and in antibody secretion rate. Analysis of affinity heterogeneity showed that such oscillations occur in higher affinity PFC subpopulations. The origin of affinity oscillations was discussed in terms of interactions among antigen and the elements of the immune network.
Putative conformation of mouse Fc gamma-receptor.
Authors: Kahn-Perles B , Sire J , Boned A , Bourgois A 
Published: December 2022

Abstract
Three cell surface molecules (m.w. = 115,000, 90,000, and 70,000) binding to the Fc portion of complexed IgG have been isolated from the murine mastocytoma line P815. Various results suggested that the 90,000 and 70,000 dalton components are generated from the 115,00 dalton molecule by spontaneous proteolytic clevages and release of 23,000 dalton fragments. It was demonstrated that these cleavages occur during cell culture and not when freshly harvested mouse spleen cells are used as an Fc gamma R cell source. The survey of the Fc gamma R molecular forms obtained from P815 and spleen cells together with their reduction products led us to conclude that the mouse Fc gamma-receptor for complexed IgG is a single chain molecule (115,000 daltons) folded into five globular subunits (m.w. eta 23,000) linked by loose connecting regions accessible to proteolytic enzymes. Three of these subunits that compose the 70,000-dalton fragment are linked by di-sulfide bonds. Furthermore, a 140,000-dalton Fc gamma-binding molecule, not identified after cell surface labeling, could be detected after internal labeling. This component could be a cytoplasmic precursor of the Fc gamma R molecule. The structural model we present here might in addition shed some light on the discrepancy that appears through the various biochemical studies performed so far on Fc gamma-receptors.
The presence of two kinds of receptors for IgE on rat mast cells.
Authors: Froese A 
Published: December 2022

Abstract
Receptors for IgE from peritoneal mast cells (RMC) of six strains of rats were studied and compared with those of rat basophilic leukemia cells (RBL). Receptors were isolated from surface iodinated and detergent solubilized cells by means of IgE-Sepharose, IgE and anti-IgE, and a rabbit antiserum specific for the receptors of RBL cells (RAR). Like RBL cells, RMC from all rate strains were shown to be associated with two receptor molecules H and R, having apparent m.w. of about 55,000 and 45,000, respectively. THe presence of both molecules could be clearly demonstrated with RAR. When IgE-Sepharose was used, the presence of H could only be unequivocally shown if large numbers of IgE molecules were bound to the RMC.
Characterization of complement resistance in Escherichia coli conferred by the antibiotic resistance plasmid R100.
Authors: Ogata R T , Levine R P 
Published: December 2022

Abstract
We have examined the effect of the antibiotic resistance plasmid, R100, on the complement (C) mediated killing of Escherichia coli K-12 strains. The viabilities, in dilute normal rabbit serum (NRS), of 5 such strains were compared with the viabilities of the same strains harboring R100. For 1 strain, J6-2, we also measured the effect of R100 on viability in normal human serum (NHS) and in guinea pig serum (GPS); in NRS, NHS,and GPS devoid of classical C pathway activity; and in NHS devoid of alternative pathway activity. Finally, we compared the depletion of individual complement components in sera exposed to J6-2 and J6-2 harboring R100. Our results demonstrate that 1) R100 renders E. coli K-12 resistant to killing by NRS, NHS, and GPS; 2) the level of resistance, which ranges from 30- to 10,000-fold, is strain dependent and serum dependent; 3) R100 inhibits killing by both the classical and alternative C pathway. Resistance appears to involve a disruption on the C pathway subsequent to the activation of C5.
High anti-TNP plaque-forming cell potential of residual mIg+ cells in a T cell population.
Authors: Mond J J , Mage M G , Rothstein T L , Mosier D E , Herrod H , Asofsky R , Paul W E 
Published: December 2022

Abstract
In the course of experiments designed to study the immune response of purified populations of B lymphocytes to thymus-independent (TI) antigens, a variety of cell purification procedures were followed. In using anti-immunoglobulin-coated dishes to separate lymphocytes bearing membrane immunoglobulin (mIg) from mIg- lymphocytes, it was found that the nonadherent fraction, which was predominantly mIg-, complement receptor negative, and nonresponsive to the B cell mitogen lipopolysaccharide, gave very substantial anti-TNP plaque-forming cell responses to 2 TI antigens. These responses could be inhibited by incubation of such cells in the presence of anti-mu and thus appeared to be attributable to mIg+ cells. The evidence suggests the existence of a population of B lymphocytes that constitute a minor component of mIg+ cells having a high potential to make in vitro antibody responses. Users of techniques that utilize anti-Ig as a tool for separating B and T lymphocytes should carefully assess the extent to which residual B lymphocytes in the mIg- population contribute to antibody responses being studied.
Existence of T cells manifesting self-reactivity indistinguishable from alloreactivity.
Authors: Altman A , Katz D H 
Published: December 2022

Abstract
The studies reported here were designed to analyze the phenotypic characteristics of self-reactive T lymphocytes induced in culture by allogeneic effect factor (AEF), as well as the control of their functional activities by the major histocompatibility complex (MHC). Unprimed T cells cultured with AEF in the absence of exogenous stimulating target cells become activated against self-antigens, as evidenced by their ability to manifest two distinct activities. First, such cells could lyse syngeneic target cells. This cytolytic activity was directed against H-2K antigens and was mediated by Lyt-2+ T cells. Second, the AEF-activated T cells could be stimulated in a secondary culture to high levels of proliferative activity by irradiated syngeneic spleen cells. The stimulator cells in this syngeneic mixed lymphocyte reaction (MLR) were found to be Thy-1-negative, Ia-positive splenic adherent cells. Stimulation in the secondary syngeneic MLR was provided by I-region specificities, and the majority of the proliferating cells were Lyt-1+ cells. Finally, AEF-induced T cells were effective in serving as effectors of graft-vs-host reactions in vivo in syngeneic recipients. These results prove that, under appropriate conditions, murine T lymphocytes can display aggressive patterns of self-reactivity that are similar in both quantity and quality to the classical patterns of alloreactivity and may have great significance for our understanding of MHC recognition processes.
Interferon production by human and murine lymphocytes in response to alloantigens.
Authors: Perussia B , Mangoni L , Engers H D , Trinchieri G 
Published: December 2022

Abstract
The production of interferon (IF) by human and mouse lymphocytes sensitized to alloantigens in mixed lymphocyte cultures (MLC) was analyzed. During primary MLC, IF appeared in the culture fluid on day 2 and was maximal on day 5. Based on several biologic criteria, the IF produced is of the "immune" type. When lymphocytes sensitized to alloantigens were reestimulated in vitro, IF was produced within a few hours of culture. In all stimulated cultures, cell proliferation was observed in spite of the high concentrations of IF. The IF-producing cells in human MLC were identified as T lymphocytes lacking the receptor for the Fc fragment of IgG molecules (Fc gamma R(-)). Human MLC supernatants containing immune type IF mediate the enhancement of natural killer (NK) cell activity and protect NK target cells from lysis.
Generation of autoreactive cytotoxic lymphocytes by spontaneously established autologous lymphoblastoid cell line.
Authors: Sumiya M , Kano S , Gonda N , Oshimi K , Takaku F 
Published: December 2022

Abstract
Using spontaneously established autologous and allogeneic LCL as stimulator and target cells, we studied the generation of autoreactive cytotoxic T lymphocytes (CTL) in primary and secondary autologous MLC. In the primary autologous MLC, cytotoxic activity was detected on the 6th day and was found to be specific to autologous LCL. In the secondary autologous MLC, cytotoxic activity was detected earlier on the 3rd day, and was at a higher level than in the case of the primary autologous MLC. This cytotoxic activity was induced in both the primary and the secondary autologous MLC when T lymphocytes were used as responder cells. When autologous LCL-primed lymphocytes were used as responder cells in the secondary MLC, autologous LCL-specific CTL were not only generated by autologous LCL but also by allogeneic LCL, and the autologous LCL-specific CTL induced by allogeneic LCL was thought to be due to the nonspecific helper effect of allogeneic LCL-stimulation.
Effect of thymopoietin pentapeptide (TP5) on autoimmunity. I. TP5 suppression of induced erythrocyte autoantibodies in C3H mice.
Authors: Lau C Y , Freestone J A , Goldstein G 
Published: December 2022

Abstract
C3H mice (young and old), when immunized with the cross-reacting rat erythrocytes, produced erythrocyte autoantibodies that usually persisted for more than 10 weeks. I.P. injection of thymopoietin pentapeptide (TP5) once or thrice weekly accelerated the loss of erythrocyte autoantibodies 7 weeks after immunization; 10 ng of TP5 was the optimal dose. The rat agglutinin responses of these immunized mice were unaffected by TP5 during the whole period of study. Spleen cells from rat erythrocyte-immunized mice, when transferred to syngeneic recipients undergoing similar immunization schedules, delayed the appearance of erythrocyte autoantibodies in the recipients. A greater delay was observed when spleen cells were taken from mice that had also received TP5 treatment.
Analysis of receptor-mediated C1q binding to human peripheral blood mononuclear cells.
Authors: Tenner A J , Cooper N R 
Published: December 2022

Abstract
The binding of C1q to human peripheral blood leukocytes has been investigated. Studies with fluorescein conjugated F(ab')2 anti-C1q show that few (0 to 4%) normal leukocytes isolated in the presence of EDTA have C1q on their surface. However, approximately 26% of the mononuclear cell population is able to bind added C1q. Quantitative binding studies using 125I-C1q show that the binding to mononuclear cells is specific, saturable, and reversible. Scatchard plot analyses indicate an approximate equilibrium constant of 1.2 times 10(7) M-1. C1q binding appears to be mediated via the collagenous portion of the molecule in that 1) type I collagen inhibits this binding; 2) C1 reconstituted from purified C1q, C1r, and C1s does not bind to mononuclear cells, whereas the same amount of free C1q binds avidly; and 3) C1q enhances the binding of aggregated IgG to mononuclear cells.
Purification and physico-chemical characterization of rabbit tumor necrosis factor.
Authors: Ruff M R , Gifford G E 
Published: December 2022

Abstract
Rabbit TNF has been purified 2000-fold by a series of salt precipitations, gel filtrations, ion exchange chromatography, and lectin affinity chromatography to a single species on SDS-polyacrylamide gel electrophoresis (SDS-PAGE). TNF activity could be recovered from nondenaturing gel systems and has been shown to be an alpha-globulin with an isoelectric point of 5.1. The m.w. was estimated to be 68,000 d by SDS-PAGE, 55,000 by gel filtration, and 52,000 by glycerol gradient centrifugation. TNF activity was stable over the pH range of 6 to 10 and was relatively heat stable, not being inactivated at 70 degrees C for 1 hr. TNF activity was pronase sensitive, but relatively trypsin resistant. Neuraminidase and phospholipase C treatment did not destroy TNF activity. Partially purified TNF was still capable of eliciting hemorrhagic necrosis in susceptible tumors. Crude TNF serum had an interferon titer of 3000 U, whereas the partially purified sample had a titer of &lt;30 U.
Regulation of lymphocyte activation: macrophage-dependent suppression of T lymphocyte protein synthesis.
Authors: Varesio L , Holden H T 
Published: December 2022

Abstract
We investigated the influence of macrophages on lymphocyte protein synthesis in C57Bl/6N mice. When activated macrophages recovered from MSV-induced regressing tumors or peritoneal macrophages induced by C. parvum injection were cultured for 6 hr with resting or Concanavalin A-stimulated normal spleen cells, a decrease of protein synthesis was observed. In contrast, peritoneal macrophages induced by injection of light mineral oil or a macrophage cell line, WEHI-3, were completely ineffective. When the mixed cultures of normal spleen cells and macrophages were fractionated, we found that Thy 1.2-positive, nylon-nonadherent cells, but not plastic adherent cells, had a depressed protein synthesis. The suppressor cells, on the contrary, were Thy 1.2 negative, adherent, and phagocytic. We concluded that activated macrophages are able to inhibit T cell protein synthesis. In comparative studies, we found that the macrophage-dependent suppression of protein synthesis correlated with the capacity of the macrophage to suppress production of a lymphokine, migration inhibitory factor, by in vitro stimulated lymphocytes. The possibility that an early block of protein synthesis is one mechanism through which suppressor macrophages inhibit the immune response is discussed.
Genetic control of the immune response to collagen. III. Coordinate restriction of cellular cooperation and antigen responsiveness by thymus-directed maturation.
Authors: Hedrick S M , Watson J 
Published: December 2022

Abstract
The H-2 restriction of T helper cells from thymus-reconstituted nude mice was examined. Hybrid athymic mice were bred from BALB/c.nu and C57BL/6.nu parental strains and reconstituted with fetal thymus tissue from either parental strain. T helper cells from these mice, immunized to SRBC, were restricted to cooperation with B cells of the thymic H-2 haplotype. These T helper cells were shown to have originated from the F1 host by functional sensitivity to antisera and complement. The H-2 restriction of thymus-reconstituted F1 nude mice was further investigated by examining expression of the Ir-collagen phenotype. Results showed that the level of antibody produced in response to type I calf collagen in thymus chimeras correlates with the H-2 haplotype (high responder or low responder) of the reconstituting thymus. These experiments indicate that the thymus environment of T cell maturation influences both the H-2 restriction and Ir-phenotype of a responding immune system.
Mechanism of immune suppression by murine neonatal fluids.
Authors: Suzuki K , Tomasi T B 
Published: December 2022

Abstract
Pretreatment of peritoneal exudate cells (PEC) for 24 to 48 hr with mouse amniotic fluid (MAF) results in a marked reduction in their ability to present antigen in a macrophage-T cell dependent antigen-induced lymphocyte proliferative assay. Since we showed that MAF did not inhibit the uptake of antigen by the antigen-presenting cells, presumably the site of action is either on "processing," T-macrophage interactions and/or on the secretion of soluble factors by macrophages. Whether suppression is the result of a direct effect on MAF on the antigen-presenting cell or indirectly via another cell type present in the PEC preparations was not established by this study. However, our data suggest that a major (although perhaps not sole) site of action of the suppressive factor(s) in MAF is at the level of the antigen-presenting cell. The biologic relevance of these in vitro observations is discussed in regard to the defects of immune function in fetal and neonatal animals.
Immunologic unresponsiveness after gastric administration of human gamma-globulin: antigen requirements and cellular parameters.
Authors: Vives J , Parks D E , Weigle W O 
Published: December 2022

Abstract
Gastric administration of human gamma-globulin (HGG) into adult A/J mice leads to the establishment of an antigen-specific unresponsive state to subsequent parenteral challenge with HGG. An unresponsive state is induced in both helper T and B lymphocyte populations. Unresponsiveness in helper T cells is of longer duration than in B cells, lasting at least 9 wk after intragastric intubation. Adoptive cell transfer of spleen cells from gastrically inoculated mice into healthy irradiated, syngeneic recipients revealed that the unresponsive state is stable upon cell transfer and that suppressor cells are present in the spleens of gastrically tolerized mice. The establishment of HGG-specific unresponsiveness is dependent upon both the dose and the form of the antigen adminstered. Soluble and deaggregated HGG are both more efficient than is heat-aggregated HGG in inducing unresponsiveness gastrically. The administered HGG is rapidly eliminated from the animal and only a small fraction reaches the circulation as immunoreactive protein. Although the cellular parameters of the systemic unresponsiveness induced by intragastric intubation with HGG appear similar to the parameters of parenterally induced unresponsiveness, the precise mechanisms by which gastric unresponsive states are established remain to be resolved.
Molecular relationships between large membrane proteins (LMP) expressed on T and B lymphocytes.
Authors: Dunlap B , Mixter P F , Koller B , Watson A , Widmer M B , Bach F H 
Published: December 2022

Abstract
Clones prepared from day 5 mixed lymphocyte cultures (MLC) were examined for the expression of large (170,000- to 200,000-dalton) membrane proteins (LMP), found on bulk cultures of resting and allogeneically activated T lymphocytes. Sodium dodecyl sulfate-poly-acrylamide gel electrophoresis (SDS-PAGE) of these proteins indicates both bulk populations and noncytotoxic clones express LMP of similar m.w. Peptide mapping further indicates that LMP of 187,000 (187K) and 200K daltons, found on T cells from bulk cultures or clones and the 220K dalton LMP from B cells, all appear to have a very similar peptide composition. This suggests a single protein (or series of closely related proteins) is differentially processed in functionally disparate populations, and hence may serve as a differentiation antigen for these populations.