bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanism of Cell-Mediated Cytotoxicity at the Single Cell Level
Authors: Grimm Elizabeth A. , Thoma John A. , Bonavida Benjamin 
Published: December 2022

Abstract
The kinetics and rate of T cell-mediated cytolysis was assessed by measuring the times required for lysis of isolated target cells by single cytotoxic lymphocytes. Single target cell lysis was determined microscopically by observing trypan blue uptake as a function of time of incubation of effector-target conjugates in agarose. Lysis of EL-4 target cells by alloimmune peritoneal exudate lymphocytes was initiated without a lag and was essentially complete at 2 hr. Both zero-order and first-order kinetics equations were analyzed for fit to the 0 to 2 hr lysis values. Statistically, the zero-order kinetic function could be rejected (p &gt; 0.05), but the first-order kinetics function (p &lt; 0.01) could not. This strong evidence for first-order kinetics of T cell-mediated cytolysis implies that within each CTL-target cell population, cytolysis occurs exponentially as a random decay process and that one event in the entire process of cytolysis is rate limiting.
The first-order equation was then applied to measurements of the rate of cytolysis in many different individual effector-target cell combinations. Significant differences in the lytic rate were apparent when either the effector or target cells were varied, with the rate constants spanning a 5-fold range. The heterogeneity of lytic rates is consistent with the hypothesis that lytic efficiency is a function of both the effector and target cells used.
Brucella Abortus Lipopolysaccharide Is Mitogenic for Spleen Cells of Endotoxin-Resistant C3H/HeJ Mice
Authors: Moreno Edgardo , Berman David T. 
Published: December 2022

Abstract
Preparations of lipopolysaccharide (LPS) from rough and smooth strains of Brucella abortus were mitogenic for spleen cells of athymic nude mice, C3H/HeAU mice, and the endotoxin-resistant C3H/HeJ mice. The mitogenic response induced by crude smooth-LPS (f5) was greater than that produced by purified smooth-LPS (f5p); however, the dose-response curves were similar for both preparations. The mitogenic activity of mouse spleen cells to both f5 and f5p was higher than that produced by stimulation with purified rough-LPS. The dose-response curves with rough-LPS were also qualitatively different from those produced with the preparations of smooth-LPS.
Determinant specific suppression of antigen-induced T cell proliferation in the guinea pig. I. Quantitation of suppressed antigen-specific T cell responses as a consequence of prior exposure to antigen in incomplete Freund's adjuvant.
Authors: Baskin B L , Rosenthal A S 
Published: December 2022

Abstract
We have asked whether a correlation exists between T cell proliferation and the in vivo suppression of delayed type hypersensitivity observed after administration of antigen in incomplete Freund's adjuvant before exposure to antigen in complete Freund's adjuvant. We find that in vivo suppression is indeed paralleled by diminished in vitro responsiveness to the immunogen. Suppression of T cell proliferation is antigen-specific, dependent upon prior immunization of antigen in IFA, and can be transferred adaptively into unprimed but not primed animals by lymphoid cells from actively suppressed syngeneic donors.
Determinant specific suppression of antigen-induced T cell proliferation in the guinea pig. II. Determinant specific suppression of in vitro T cell responsiveness parallels a selective suppression of anti-hapten but not anti-carrier antibody responses.
Authors: Baskin B L , Blake J T , Rosenthal A S 
Published: December 2022

Abstract
Using an antigen of defined physical structure with precisely mapped immunogenic sites, we asked whether those molecular sites previously shown to be critical for immune response gene-mediated initiation of T cell proliferation and T help correspond to the same molecular regions capable of inducing antigen-specific suppression of T cell proliferation and antibody production. Inbred strain 2, 13, and 2 x 13 F1 hybrid guinea pigs were immunized with various species variants or fragments of insulin adjuvant before subsequent immunization with antigen in complete Freund's adjuvant. Analysis of the patterns of depressed T cell responsiveness showed a striking correspondence to the Ir gene-dependent mechanism that controls the recognition of discrete regions within the insulin molecule observed in T cell help in antibody production. In addition, suppression of carrier-specific T cells parallels suppression of anti-hapten antibody responses when hapten is presented on the suppressed carrier without a concomitant suppression of the anti-carrier antibody response.
The V region sequence of lambda Bence-Jones protein Wh: evidence for separate germ-line sets within lambda-subgroups.
Authors: Kiefer C R , Patton H M , McGuire B S , Garver F A 
Published: December 2022

Abstract
The complete variable region sequence of the glycosylated Bence-Jones protein Wh has revealed that the most hypervariable segments of the first and third complementarity-determing regions (CDR) are identical with those of another glycosylated Bence-Jones protein (Nei) of the same lambda-subgroup. The carbohydrate is attached in both proteins at the identical sequences in the third CDR, and the sequences of the first CDR differ at only one position in fourteen. Because CDR sequence comparisons more sensitively reflect overall germ-line V gene similarities, proteins Wh and Nei could possibly reflect a "set" relationship analogous to the mouse V kappa isotype. Cluster analyses of currently available V lambda sequences supported this suggested relationship.
Production of Con A-induced helper T cell replacing factor requires a T cell and an Ia-positive non-T cells.
Authors: Swain S L , Dutton R W 
Published: December 2022

Abstract
Evidence is presented that indicates that two cells are required for the production of Con A-induced, helper T cell replacing factor. The factor production involves both a T cell and an IA,IE/C-positive non-T cell. The T cell and the Ia-positive cell need not be H-2 compatible. Limiting dilution analyses suggested that the Ia-positive cell is limiting in normal spleen. A hypothesis is put forward that the activation of T cells by Con A may involve "gluing" normally specific, functional T cells to the Ia expressing cells with which they would normally interact in antigen-specific activation.
Differentiation of Thy 1-bearing cells from progenitors in long-term bone marrow cultures.
Authors: Jones-Villeneuve E V , Rusthoven J J , Miller R G , Phillips R A 
Published: December 2022

Abstract
Lone-term marrow cultures, established according to the technique described by Dexter, contain a colony-forming cell (CFU-T) that produces Thy 1-positive progeny after stimulation with PHA-induced conditioned medium from human leukocytes. When 10(-7) M hydrocortisone is added to the medium for the long-term cultures CFU-T can be maintained in vitro for at least 16 weeks. Cells from individual colonies lack precursors for cytotoxic lymphocytes but can provide nonspecific help required for the generation of cytotoxic lymphocytes.
Characterization of the stimulator cells in the murine primary mixed leukocyte response.
Authors: Minami M , Shreffler D C , Cowing C 
Published: December 2022

Abstract
Macrophage-enriched and depleted spleen cell populations were examined for their ability to stimulate a murine 1 degree mixed leukocyte response. A quantitative comparison of unfractionated spleen cells, Sephadex g-10 passed spleen cells, 4-hr glass adherent and 24-hr glass adherent spleen cells revealed that a potent 1 degree MLR stimulator cell was phagocytic and that T and B lymphocytes failed to stimulate a response. By using several inb;ed and recombinant mouse strains congenic for different subregions of the MHC, it was found that macrophage-enriched cells were capable of inducing an MLR against K, D, I-A, and I-E differences and against K and D mutants. Both macrophage-enriched and depleted spleen cells failed to stimulate responses when the stimulator and responder differed at I-J, I-C, S, or G. Moreover, MLR stimulation induced by K or D region differences alone was dependent upon stimulator cells that expressed Ia antigens. Therefore, it would appear that only a minor subpopulation of the cells that express the relevant MHC alloantigens is immunogenic in the murine 1 degree MLR.
Lymphocytes bearing Fc receptors for IgE. IV. Formation of IgE-binding factor by rat T lymphocytes.
Authors: Yodoi J , Ishizaka K 
Published: December 2022

Abstract
Culture of mesenteric lymph node cells from rats infected with Nippostrongylus brasiliensis resulted in the release of a soluble factor (IgE-binding factor) that can inhibit rosette formation of Fc epsilon R(+) lymphocytes with IgE-coated red cells. The factor is specifically absorbed with IgE-coated Sepharose. It has a m.w. of between 10,000 and 20,000. The major source of IgE-binding factor appears to be Fc epsilon R(+) T cells. The formation of IgE-binding factor by the lymphocytes was enhanced by IgE added to the culture medium. Evidence was obtained that Fc epsilon R(+) cells are involved in the induction of IgE-induced factor formation. Normal rat lymphocytes cultured alone failed to release IgE-binding factor, but incubation of normal lymphocytes with rat IgE resulted in the formation of IgE-binding factor and an increase in the proportion of Fc epsilon R(+) cells. It was also found that normal T cells formed the soluble factor upon incubation with IgE. In the induction of factor formation by normal lymphocytes, Fc gamma R(+) cells are essential; an Fc gamma R-depleted fraction failed to form IgE-binding factor upon incubation with IgE. The results suggest that interaction of IgE with Fc epsilon R(+) T cells and Fc gamma R(+) T cells induces the formation of IgE-binding factor(s).
Active site radioimmunoassay for human urokallikrein and demonstration by radioimmunoassay of a latent form of the enzyme.
Authors: Silver M R , ole-MoiYoi O , Austen K F , Spragg J 
Published: December 2022

Abstract
A radioimmunoassay specific for the active site in urokallikrein has been developed with a monospecific antibody that neutralizes the enzymatic activities of urokallikrein and a radioligand purified so as to maintain the active site. In order to favor the involvement of the antibody with high affinity for the active site in the competition between urokallikrein in biological fluids and radiolabeled urokallikrein, the radioligand was separated from denatured radiolabeled urokallikrein by affinity chromatography for the active site. The concentration of specific IgG used in the assay bound approximately 80% of the radioligand, which was displaced in a dose-related fashion by 0.2 to 2.5 ng of the unlabeled urokallikrein. When random urine samples from 21 healthy volunteers were assessed for endogenous urokallikrein by both active site radioimmunoassay and kinin generation, there was a linear relationship between the results of the two assays with a correlation coefficient of 0.89. A combined correlation plot of the results of the bioassay and the active site radioimmunoassay for the 21 urine samples before and after trypsin activation gave a linear regression line with a correlation coefficient of 0.91. The finding that trypsin activation increased the urokallikrein concentration of urine to a similar extent in both the radioimmunoassay and the bioassay means that latent urokallikrein was not detected until its active site was uncovered.
Experimental allergic encephalomyelitis supernatant transfer activity (EAE-STA) in Lewis rats:immunobiologic and initial biochemical properties.
Authors: Whitacre C C , Paterson P Y 
Published: December 2022

Abstract
Supernatants derived from incubated lymph node cells (LNC) of Lewis rats sensitized to neuroantigen-adjuvant have the capacity to transfer experimental allergic encephalomyelitis (EAE) to syngeneic recipients. Sensitization of donors with guinea pig or rat spinal cord adjuvant by either of two routes of injection was effective in generating EAE supernatant transfer activity (EAE-STA). Despite transfer of typical EAE histopathologic lesions, which were intense and disseminated throughout the neuraxis in some animals, recipient animals invariably remained clinically well. Donor sensitization with purified myelin basic protein of guinea pig or rat origin was conspicuously ineffective in generating EAE-STA. Absorption studies revealed that EAE-STA was diminished after exposure to guinea pig or rat spinal cord or guinea pig or rat kidney, but it was not demonstrably reduced after absorption with neonatal rat spinal cord lacking encephalitogenic activity or with guinea pig or rat myelin basic protein or lysozyme. EAE-STA is stable at -20 degrees C/4 days, -70 degrees C/2 days, 4 degrees C/18 hr, and 56 degrees C/1 hr, and has a m.w. in excess of 100,000 daltons.
The cellular nature of concanavalin A-stimulated antibody-dependent cell-mediated cytotoxicity.
Authors: Connolly J M , Wunderlich J R 
Published: December 2022

Abstract
Enhanced antibody-dependent cytotoxic cell (ADCC) activity, generated in vitro by concanavalin A (Con A) stimulation of human peripheral blood lymphocytes, was analyzed to identify the nature of the killer (K) cell. Stimulated and unstimulated 2-day cultured cells were separated into sheep erythrocyte rosetting (E+) and non-rosetting (E-) subpopulations, and ADCC activity was determined by using the slopes of linear dose-response plots as a measure of K cell activity. Quantitative comparisons were made by examining activity on a per cell basis ("specific" activity) and total K cell activity recovered per subpopulation. This analysis revealed that although the E- cells were enriched for specific ADCC activity, the E+ subpopulation contained the major proportion of the total recovered activity and nearly all of the Con A-induced increase in K cell activity.
Role of sialic acid in the macrophage glycolipid receptor for MIF.
Authors: Liu D Y , Petschek K D , Remold H G , David J R 
Published: December 2022

Abstract
Acidic glycolipids from guinea pig macrophages enhance the response of macrophages to migration inhibitory factor (MIF), suggesting a role of glycolipid receptors for this lymphocyte mediator. Neuraminidase treatment of these glycolipids results in the loss of their biologic activity. This activity remains intact after incubation of the glycolipids with beta-galactosidase. In order to investigate whether sialic acid is essential for the macrophage's response to MIF, macrophages were incubated with neuraminidase. Neuraminidase treatment of peritoneal exudate cells results in the abrogation of macrophage responsiveness to MIF. Other exoglycosidases such as beta-galactosidase and beta-glucosidase had no effect upon the macrophage response. The effect of neuraminidase was found to be reversible within 18 hr. These experiments suggest that macrophage glycolipids containing sialic acid are components of the macrophage receptor for MIF.
Newly transformed schistosomula spontaneously lose surface antigens and C3 acceptor sites during culture.
Authors: Samuelson J C , Sher A , Caulfield J P 
Published: December 2022

Abstract
The binding of rat anti-schistosome antibody and rat C3 to the surface of newly transformed schistosomula of S. mansoni was measured by quantitative immunofluorescence during the first 48 hr of their development in vitro. Schistosomula, cultured in media either with or without serum, lost antibody or C3 from their surface exponentially with a halftime of 5 hr for both labels. The loss of the surface molecules is seen in parasites that are labeled and then cultured as well as in parasites cultured and then labeled, indicating that the labeling procedure itself is not inducing the observed change. This immunochemical modification in the schistosomulum surface appears to be independent of host molecule adsorption and intrinsic to the development of the parasite.
Interferon activation of "pre-spontaneous killer" (pre-SK) cells and alteration in kinetics of lysis of both "pre-SK" and active SK cells.
Authors: Targan S , Dorey F 
Published: December 2022

Abstract
Interferon augments spontaneous killer cellular cytotoxicity (SKCC). This modulation may be vital in both tumor resistance and host viral defenses. To date, whether increased numbers of effector cells or activation of individual effector cells is responsible for this augmentation has not been established. Using a single cell assay where SK killing is directly visualized by the reading of trypan blue uptake at various time points by effector-target cell conjugates plated in agarose gel, we measured in vitro alterations in percentage of conjugate formation, number of active SK cells, and kinetics of SK cell lysis at the single cell level after 1 hr of interferon incubation. After interferon, there is no difference in number of cells that bind K-562 targets. This augmentation of cytotoxicity is due to both recruitment of new effector cells and an activation of the lytic process of both the new and already active SK cells.
Failure of lymphokine-producing lymphocytes from aged humans to undergo activation by recall antigens.
Authors: Sohnle P G , Larson S E , Collins-Lech C , Guansing A R 
Published: December 2022

Abstract
In order to understand better the causes of diminished delayed hypersensitivity in the elderly, we studied lymphocyte function in 10 healthy subjects over 80 years of age. Markedly decreased antigen-stimulated lymphokine production (3 of 30 assays positive versus 24 of 31 in young control subjects) was the most significant finding in the elderly subjects and appeared to be the best explanation for their reduced cutaneous responses to recall antigens. Although mitogen-stimulated lymphocyte transformation in the elderly group was more sensitive to suppression by prostaglandin E2 than that of the young group, direct prostaglandin action did not appear to explain the diminished antigen-stimulated lymphokine responses. The nonspecific mitogen concanavalin A elicited normal lymphokine responses in 9 of 10 elderly subjects, indicating that lymphocytes from the elderly have a normal capacity for lymphokine production when activated by a sufficient stimulus. Therefore, diminished delayed hypersensitivity in aged humans may be related to deficient lymphokine production, which in turn appears to involve a decreased capacity of the lymphocytes producing these mediators to undergo activation by recall antigens.
Purification, immunochemical, and biologic characterization of the Schistosoma circulating M antigen.
Authors: Carlier Y , Bout D , Strecker G , Debray H , Capron A 
Published: December 2022

Abstract
Circulating M antigen, specific for genus Schistosoma, was previously described in serum, urine, patients' milk, and in serum and urine of animals infected by S. mansoni. The M antigen was thermostable and soluble in trichloroacetic acid. It was not hydrolyzed by protease, ribonuclease, amylase, or neuraminidase but destroyed by sodium metaperiodate. In the present study, we have purified the M ag by using trichloroacetic acid solubility, DEAE Sephadex, and immunoadsorption. The M ag showed a neutral electric charge, a m.w. heterogeneity, and was only stained by periodic acid-Schiff. The composition study revealed M ag was a glycoprotein with a polysaccharide moiety (63% of the molecules) particularly rich in galactose, fucose, glucosamine, and mannose, and with a high molecular ratio of serine and threonine. The presence of O-glycosidic linkage allowed M ag to be considered as a mucin or a mucus glycoprotein-like component. It was localized in the cell wall of the gut of adult worms.
The specificity of uptake of model immune complexes and other protein aggregates by the murine reticuloendothelial system.
Authors: Finbloom D S , Abeles D , Rifai A , Plotz P H 
Published: December 2022

Abstract
We have studied the selectivity of the murine reticuloendothelial system in recognizing and removing from the blood model immune complexes and several aggregated proteins. Although both IgG anti-DNP model immune complexes and micro-aggregated albumin exhibited rapid hepatic uptake, which is saturable, they did not cross-inhibit each other. Aggregates of ovalbumin, a glycoprotein rich in mannose (a sugar recognized by Kupffer cells), had no effect on the uptake by the liver of either IgG immune complexes or micro-aggregated albumin. The finding that transferrin aggregates were not taken up by the liver at all suggests that aggregation alone is not sufficient to overcome the lack of a specific hepatic receptor for that protein. Thus, several mechanisms exist whereby aggregated proteins can be cleared from the blood by the reticuloendothelial system, an observation consistent with the selective failure of reticuloendothelial function found in several human diseases.
Modulation of tumor cell susceptibility to humoral immune killing through chemical and physical manipulation of cellular lipid and fatty acid composition.
Authors: Schlager S I , Ohanian S H 
Published: December 2022

Abstract
Line-10 tumor cells cultured for 24 hr in lecithin-rich normal human plasma or with synthetic lecithin showed a 5- to 8-fold increase in their lecithin:sphingomyelin mole ratio without being affected in their total lipid content or cholesterol:phospholipid mole ratio. These cells were more sensitive to killing by antibody plus complement (C) than untreated controls. Line-10 cells that underwent a homogeneously catalyzed hydrogenation reaction were reduced 6-fold in their content of unsaturated fatty acid compared to controls; the lipid content of these cells was largely unaffected. These cells were more resistant to antibody-C mediated killing than controls. These modifications in cellular lipid and fatty acid composition could be reversed when the cells were recultured for 24 hr in serum-containing tissue culture medium; the cells regained control levels of susceptibility to antibody-C killing at this time. These results suggest that by manipulating the lipid or fatty acid composition of a tumor cell, either indirectly by changing the lipid composition of the environment in which the cell resides or by directly altering the chemical nature of a cellular lipid constituent, the susceptibility of the cell to humoral immune killing can be modulated.
Idiotypic analysis of anti-GAT antibodies. VII. Common idiotype on hybridoma antibodies to poly(Glu60 Ala40)
Authors: Ju S T , Pierres M , Germain R N , Benacerraf B , Dorf M E 
Published: December 2022

Abstract
A single DBA/2 mouse, immunized with L-glutamic acid60-L-alanine40 (GA), was used to produce hybridoma cell lines. Seven hybridoma anti-GA antibodies were obtained for idiotypic analyses. Two hybridoma anti-L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT) antibodies, preferentially reactive to GA, were studied in parallel. Anti-idiotypic antisera to purified anti-GAT and anti-GA serum antibodies and to hybridoma anti-GA antibodies were analyzed by idiotype binding and inhibition of idiotype binding assays. Five of the nine hybridoma antibodies exhibited common GA-1 idiotypic specificities previously demonstrated on the majority of anti-GA antibodies of inbred mouse strains of differing immunoglobulin heavy chain linkage groups; these hybridoma antibodies also possessed private idiotypic determinants. Two GA-1 negative hybridoma anti-GA antibodies appeared identical by immunochemical criteria, arguing that somatic hybridization does not artifactually generate private idiotypic determinants. The results demonstrate that the common GA-1 idiotype system is associated with a family of nonidentical but idiotypically related antibody molecules present in a single DBA/2 mouse, and these antibodies are part of the "GA-1 idiotypic family".