bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolation and Characterization of the Sheep Erythrocyte Receptor in Man
Authors: Pyke Kenneth W. , Rawlings Gayle A. , Gelfand Erwin W. 
Published: December 2022

Abstract
Properties of the sheep erythrocyte receptor on human lymphocytes were examined from two different aspects: inhibition of E-rosette formation by antisera, and extraction of T and non-T cells with 3 M KCl. Antisera to several T cell populations produced significant inhibition of E-rosette formation by human peripheral blood lymphocytes, whereas anti-B cell, anti-β2-microglobulin, anti-I, and anti-i were ineffective. Sera with activity to HL-A subgroups on the HPBL tested produced complete rosette inhibition, although nonspecific anti-HL-A produced no inhibition. T cell preparations extracted by a 3M KCl technique contained activity that could be bound to SRBC and produce inhibition of rosette formation by HPBL. This inhibitory component could be quickly eluted from the SRBC and retain its inhibitory activity. No inhibitory activity could be demonstrated in extracts of B cells and non-lymphoid cells. These results suggest that 1) T cell-specific and HL-A specific antisera inhibit E-rosette formation; 2) β2-M is not involved in the SRBC receptor as an active component; and 3) the receptor may be isolated by 3 M KCl extraction, and partially purified by the use of SRBC as a specific immunoadsorbent, without loss of biologic activity.
Lymphocyte Abnormalities in Aleutian Disease Virus Infection of Mink: Decreased T Lymphocyte Responses and Increased B Lymphocyte Levels in Persistent Viral Infection
Authors: Perryman Lance E. , Banks Keith L. , McGuire Travis C. 
Published: December 2022

Abstract
Persistence of virus and a marked hypergammaglobulinemia are consistent features observed in mink with Aleutian disease virus infection. These events may result from altered lymphocyte function in infected mink. To test this possibility we determined the ability of lymphocytes from infected mink to respond to phytolectins (PHA and Con A), and a specific antigen (KLH) in a lymphocyte transformation test and quantitated the number of lymphocytes bearing surface immunoglobulin. Infected mink had a significantly lower response than normal mink to PHA and Con A (p &lt; 0.025), and the difference in the responses increased progressively with time post-infection. Infected mink immunized with KLH also had a decreased ability to respond to this antigen when compared to normal immunized mink (p &lt; 0.001). The number of lymphocytes bearing surface immunoglobulin was significantly elevated in three of 10 mink infected for 10 weeks, and in all of seven mink infected 32 weeks (p &lt; 0.001).
Naturally-Ocurring Low Molecular Weight IgM in Patients with Rheumatoid Arthritis, Systemic Lupus Erythematosus, and Macroglobulinemia
Authors: McDougal J. S. , Harisdangkul Valee , Christian C. L. 
Published: December 2022

Abstract
Some physicochemical properties of naturally occurring low molecular weight IgM (LMW IgM), IgM and their subunits obtained by reduction-alkylation were compared. On the basis of analytical ultracentrifugation, SDS polyacrylamide electrophoresis, analytical Sephadex chromatography, and heavy (H) and light (L) chain composition purified LMW IgM had an S20, w constant of approximately 8S, a molecular weight of 195,000 to 205,000 and a structural formula H2L2. Reduction and alkylation of IgM (IgM RA) by two techniques produces two components which could be distinguished by analytical ultracentrifugation, sucrose density ultracentrifugation, and gel filtration studies. IgM RA-cys had an estimated molecular weight similar to LMW IgM and IgM-2ME had physical properties similar to IgG. The molecular weights of H and L chains of IgM and LMW IgM were similar: 69,000 to 75,500 and 26,000 to 27,000, respectively. Unlike LMW IgM and IgM RA-cys, the less dense IgM RA reduced with 2ME dissociated into half subunits, and free H and L chains in SDS gel electrophoresis, indicating that it lacked intra-subunit disulfide bonds. J chain was not detected in LMW IgM or in the chromatographically purified reduced-alkylated subunits from a patient whose IgM contained J chain.
Carbohydrate analyses of IgM, LMW IgM, and reduced-alkylated IgM products did not demonstrate differences in individual sugars or in the percentage of total carbohydrate.
The different sedimentation and gel filtration properties of the two components obtained by reduction-alkylation of IgM could not be attributed to variations in peptide chain or carbohydrate content, rather they are probably dependent on conformational changes resulting from variable reduction of intra-subunit disulfide bonds.
Early Steps in Specific Tumor Cell Lysis by Sensitized Mouse T Lymphocytes
Authors: Martz Eric 
Published: December 2022

Abstract
Addition of high molecular weight dextran to culture medium prevents the initiation of T lymphocyte-mediated killing by holding the cytolytic T lymphocytes (CTL) and target cells in suspension and preventing intercellular contact. Suspension in 10% dextran was used to interrupt the ongoing formation of adhesions between CTL and target cells already in contact in a centrifuged pellet. The results demonstrate that 1) firm adhesions form between CTL and target cells within 1 min at 37°C; 2) once formed, these adhesions are stable at low temperature and are resistant to mechanical shearing forces; 3) these adhesions can be disrupted by EDTA; 4) immediately after the adhesions form, separation of the CTL from the target cells prevents lysis of the latter; 5) after incubation of targets adhering to CTL for an additional 6 min at 37°C, removal of the CTL no longer prevents target cell lysis. Thus, target cells become “programmed” for subsequent lysis within a few minutes after contact with CTL, after which lysis occurs during the next several hours without further participation of the effector cell.
At 15°C, adhesions form 1/17 as fast as at 37°C. Programming of target cells for lysis occurs 1/76 as fast at 15°C as at 37°C. Thus, the programming for lysis step is about 4-fold more temperature dependent than the adhesion step.
In addition to being detected by subsequent target cell lysis in 10% dextran, the adhering cell clusters can be counted with low power microscopy. This permitted verification that EDTA separates the clusters after programming for lysis is complete. Moreover, the great majority of the clusters seen at 37°C are antigen-specific. Knowledge of the cluster size distribution and the subsequent level of lysis permits the deduction that not less than 6% of the sensitized peritoneal cell populations used were CTL.
Immunochemical Characterization of the Anti-RNA Antibodies Found in Scleroderma and Systemic Lupus Erythematosus
Authors: Alarcón-Segovia Donato , Fishbein Eugenia 
Published: December 2022

Abstract
In a previous study, all 40 sera from patients with scleroderma, 20 of 40 sera from SLE patients, but none of 40 sera from normal controls, were found to have antibodies to ssRNA. All scleroderma sera were also found to react with HSA-coupled uridine and UMP and their reaction with ssRNA could be inhibited by uracil, uridine, and UMP.
To characterize further these uracil-specific anti-RNA antibodies found in scleroderma and compare them with the anti-RNA antibodies found in SLE, we tested their reactivity with Poly (U) and with Poly (A)·Poly(U) in CIE. All 40 scleroderma sera reacted with Poly (U) and all but one failed to react with Poly (A)·Poly(U). This same serum was the only one in which the reaction with Poly (U) could not be inhibited with uracil.
Reactivity of SLE sera was strikingly different from that found in scleroderma sera. Seventeen of 34 SLE sera studied reacted with ssRNA but only four of these reacted with Poly (U). Conversely, two SLE sera that reacted with Poly (U) did not react with ssRNA. Fifteen reacted with Poly (A)·Poly (U) and only two of these failed to react with ssRNA. Five SLE sera which were reactive with ssRNA did not precipitate with Poly (A)·Poly (U).
All SLE sera which reacted with Poly (U) could be inhibited with uracil, although less effectively than in scleroderma. Reactivity with Poly (A)·Poly (U) was not inhibited with uracil nor with adenosine.
These findings confirm that antibodies to RNA that are found in scleroderma are directed to uracil and thus specific to ssRNA, whereas RNA antibodies found in SLE sera are heterogeneous and directed to either the base, to the site of union of the base and sugar moiety to the ribose backbone, or to the helical structure of double stranded RNA. These differences and the respective antigenic specificities of these anti-RNA antibodies found in scleroderma and SLE may be theoretically important.
Relationship between Immunoglobulin-Bearing Lymphocytes and Cells Reactive with Sensitized Human Erythrocytes
Authors: Kurnick James T. , Grey Howard M. 
Published: December 2022

Summary
Peripheral blood lymphocytes were evaluated for surface immunologlobulin and the ability to form rosettes with anti-Rh coated erythrocytes (EA). Ninety percent of the EA-rosetting cells also possessed surface IgG. This surface IgG was mostly lost after a 1-hr incubation at 37°C. These data are discussed in relation to the work of Fröland and Natvig and Lobo, et al., and the suggestion is made that the EA-rosette assay detects a population of cells with a very avid Fc receptor that bears cytophilic IgG on its surface.
Evidence for Cell-Receptor Activity in Lymphocyte Stimulation by Staphylococcal Enterotoxin
Authors: Warren John R. , Leatherman Dennis L. , Metzger Joseph F. 
Published: December 2022

Abstract
A wide dose-response curve and the inhibitory effect on mitogenicity of specific antitoxin suggest that polyclonal lymphocyte activation by staphylococcal enterotoxin requires direct interaction of toxin with lymphocyte receptors of low avidity for the protein. Staphylococcal enterotoxins A, B, and C1 demonstrated equivalent mitogenic activity. Lymphocyte receptors involved in enterotoxin activation thus appear to be specific for nonantigenic regions of the toxin molecule. Monosaccharide (hapten) inhibition data indicate that lymphocyte receptors for staphylococcal enterotoxin lack α-mannoside, galactose, acetylgalactosamine, acetylglucosamine, and fucose (or closely related saccharides) as determinant sugars and thus differ significantly in structure from lectin cell receptors.
Presidential Address to the American Association of Immunologists, Delivered in Atlantic City, New Jersey, April 17, 1975
Authors: Kunkel Henry G. 
Published: December 2022

Abstract
Each year it has been the privilege of the President of the Association to make a few remarks to the membership. Frequently this has been a scientific presentation, but it also has taken many other forms. Last year, when I found Baruj Benacerraf vascillating on the question as to which path he should take, I urged him to seize the opportunity and give us some of his more philosophical thoughts. We had heard enough about Ir genes. I stated that I would certainly follow his example next year. He, of course, then did this very successfully. In my own case, however, as next year drew ever closer, I had some second thoughts. It suddenly occurred to me that a scientific talk published in the Journal of Immunology would be a valuable asset. I would have to be sole author on the paper, something that hasn't occurred in many years and this would be quite impressive with my grants soon coming up for renewal.
IgG Antibody Suppression of the IgM Antibody Response to Toxoplasma Gondii in Newborn Rabbits
Authors: Araujo Fausto G. , Remington Jack S. 
Published: December 2022

Abstract
Studies were performed in an experimental rabbit model in an attempt to explore the possibility that the absence of an IgM antibody response in human infants congenitally infected with Toxoplasma may be caused by a suppressive effect of IgG antibody passively transferred from the mother. The IgM antibody response to Toxoplasma gondii infection in newborn rabbits previously injected with IgG Toxoplasma antibody was significantly suppressed as determined by an immunofluorescent antibody assay (IgM-IFA). In newborn rabbits infected with Toxoplasma, IgM-IFA antibody was first demonstrated 15 days after infection and reached a peak titer of 1:128 in two animals on days 20 and 25. In newborn rabbits injected with IgG Toxoplasma antibody and then infected with Toxoplasma, the IgM-IFA antibody response was considerably lower; the highest titer was 1:16 and occurred 25 and 30 days after infection. The results of these studies lend support to the concept that maternally transmitted IgG may suppress the IgM antibody response in the fetus and newborn infant.
Cytotoxic Activity of Lymphocytes
Authors: Reed William P. , Lucas Zoltan J. 
Published: December 2022

Abstract
Macrophage cell-mediated cytolysis (M-CMC) of tumor cells may be measured by culturing target cells on macrophage monolayers and determining target cells on macrophage monolayers and determining target cell survival by either 86Rb or 3H-thymidine incorporation. Using these techniques, one can demonstrate cytotoxicity of non-immune human and rat macrophages to a variety of tumor cell lines. Toxicity becomes maximal 8 to 16 hr after attaching macrophages to plastic surfaces and disappears after 36 to 48 hr. Addition of Escherichia coli endotoxin at 48 hr restores macrophage toxicity. Culture of macrophages on plastic surfaces also results in the release, non-specifically, of a soluble cytotoxin whose kinetics of release, disappearance, and reappearance after endotoxin all parallel the M-CMC. The amount of toxin released into cultures containing target cells is markedly reduced, suggesting that it is the mediator of the M-CMC and that it is utilized or adsorbed during target destruction. Sephadex G-100 chromatography and treatment with heterologous anti-lymphotoxin can distinguish this toxin from lymphotoxin.
Receptors for Antigen on Lymphoid Cells
Authors: Greeley Elizabeth A. , Scott David W. 
Published: December 2022

Abstract
The nature of specific adherence of rat anti-TNP PFC to TNP-GRBC has been investigated with PLL-fixed antigen monolayers as cellular immunoadsorbents and as plaque indicators. The immunoglobulin nature of the molecule responsible for PFC adherence is suggested by the fact that pretreatment of the PFC with rabbit anti-rat Ig antisera, but not anti-histocompatibility antisera, inhibits adherence. Removal of the adherence capacity of early PFC with the proteolytic enzymes papain and pronase, or by “capping” with anti-Ig is followed by slow regeneration of the ability to adhere, suggesting that adherence is due to membrane rather than secreted immunoglobulin, the latter being detectable within minutes after enzyme treatment. Several time-related events relating to PFC adherence were observed. 1) Both direct and indirect PFC are capable of specific adherence; the ability to adhere, however, tends to decline with time, especially after secondary immunization. 2) Although early PFC adherence is unaffected by trypsin treatment, later populations become increasingly sensitive. 3) Pretreatment of PFC at various times after primary immunization with antisera specific for rat µ-chain indicates that IgM and possibly early IgG-secreting PFC have µ heavy chains on their surface. These data suggest that the PFC membrane is progressively changing during the maturation of the antibody response.
Differential Susceptibility of Rabbit sIgA Subclasses to Trypsin Cleavage: Characterization of the Fragments Obtained from the g Subclass
Authors: Tseng Jeenan , Knight Katherine L. 
Published: December 2022

Abstract
Rabbit secretory IgA (sIgA) was digested with trypsin at 37°C for 30 min and four fractions were isolated by gel filtration. These fragments were characterized by ultracentrifugation, and by their antigenic properties as undigested sIgA, Fab2α and Fc2α. (Two Fc2α fragments differing in their content of secretory component were obtained.) The IgA-f subclass molecules were resistant to cleavage and were found in the undigested sIgA fraction; the IgA-g subclass molecules were cleaved into Fc2α and Fab2α fragments. The g allotypic determinants of IgA-g molecules were found on both the Fc2α fragments and the Fab2α fragments. The Fc2α and Fab2α fragments obtained from trypsin-digested sIgA were compared by means of antigenic properties and peptide maps with the Fc2α and Fab2α fragments obtained from papain-digested sIgA; no differences attributable to the α-chain were found. Thus, papain and trypsin cleave the α-chain of IgA-g molecules at similar but not necessarily identical postions.
Lysis of Tumor Cells by Antibody and Complement
Authors: Boyle Michael D. P. , Ohanian Sarkis H. , Borsos Tibor 
Published: December 2022

Abstract
The increase in susceptibility to killing by rabbit antibody and guinea pig complement of guinea pig hepatoma cells (line-10), after treatment with certain metabolic inhibitors, did not correlate with the mobility of antigen on the cell surface as measured by indirect immunofluorescence.
The Identification of a Previously Unrecognized Subcomponent of the First Component of Complement
Authors: Assimeh Seth N. , Painter Robert H. 
Published: December 2022

Abstract
The use of an affinity chromatography method designed to isolate C1 from serum has led to the discovery of a novel plasma protein, II-P2, associated with C1. The persistent Ca++-dependent association of II-P2 with C1 subcomponents following euglobulin precipitation, affinity chromatography on Sepharose-IgG, and density gradient ultracentrifugation indicates that II-P2 might be a C1 subcomponent. Using purified preparations of II-P2 it was found that a) II-P2 was retained on Sepharose-IgG through a Ca++-dependent link with C1q, b) II-P2 enhanced the C1 activity of mixtures of C1s and C1q in a dose-dependent fashion, c) II-P2 bound firmly to EAC1q4 cells and enhanced their C1s-binding ability. Fractionation of C1 by DEAE-Cellulose chromatography under the conditions that led to the original identification of C1q, C1r, and C1s resulted in recovery of II-P2 in the fractions containing C1r. The evidence presented confirms that II-P2 is a C1 subcomponent (C1t).
The Macromolecular Structure of the First Component of Complement
Authors: Painter Robert H. , Assimeh Seth N. , Painter Robert H. 
Published: December 2022

Abstract
The binding of C1 to IgG and the interactions between C1 subcomponents have been studied by affinity chromatography of serum C1 and purified C1 proteins on Sepharose-IgG. Affinity chromatography of serum on Sepharose-IgG resulted in the binding of C1; subsequent washing with EDTA removed only C1s and C1t. Affinity chromatography of serum-EDTA on Sepharose-IgG resulted in binding of only C1q and C1r. Affinity chromatography of serum on Sepharose-tryptophan-modified-IgG resulted in the binding of only C1r and C1s. By the use of purified C1 proteins and Sepharose-IgG in binding studies it was confirmed that both C1q and C1r bind independently to sites on IgG and hold C1s and C1t by Ca++-dependent bonds. Measurements of the hemolytic activity of various combinations of C1 subcomponents confirmed the data obtained by the affinity binding studies. Both C1t and C1r independently enhanced the C1 activity of C1q-C1s mixtures; maximal activity required all four subcomponents. Sucrose gradient ultracentrifugation of mixtures of C1 proteins showed formation of the following complexes: C1qs (12S), C1qrs (15S), C1qst (18–23S), and C1qrst (19S).
The evidence suggests that the spatial sequence of the components of the Sepharose-IgG-Serum C1 complex is: Sepharose-IgG: C1q: C1t: C1s: C1r: IgG-Sepharose. The probable physiologic significance of this model is discussed.
Interaction Between Lymphocytes and Inflammatory Exudate Cells
Authors: Yoshinaga Masaru , Nakamura Shuji , Hayashi Hideo 
Published: December 2022

Abstract
Thymocytes of C3H/He mice were poorly triggered to induce DNA synthesis by phytohemagglutinin but fairly well triggered when they were mixed with small number of inflammatory peritoneal exudate polymorphonuclear leukocytes or macrophages, or with the soluble product(s) of these cells.
Peritoneal exudate cells were mainly harvested at 3 hr, largely consisting of polymorphonuclear leukocytes, and at 96 hr, largely consisting of macrophages, after intraperitoneal injection of 0.2% sodium caseinate. Addition of 22 to 26 × 103 of 3-hr exudate cells, 22 to 24 × 103 of 48-hr exudate cells, or 22 to 24 × 103 of 96-hr exudate cells to syngeneic thymocyte culture (3 × 106) resulted in marked enhancement of DNA synthesis by thymocytes stimulated with 1 µ1 PHA. Similar enhancement of DNA synthesis was also observed in the presence of 200 µ1 of cellfree supernatant fluid of peritoneal exudates of 3 hr or 9 hr after casein stimulation. Conversely, two hundred microliters of 0-hr, 48-hr, or 96-hr peritoneal fluid showed a slight suppressing effect on thymocyte response and 50 to 100 µl of these exudates showed no enhancing effect. Furthermore, 50 to 800 µ1 of culture supernatants from 1.6 × 106 cells/4 ml of 3-hr exudate cells, 96-hr exudate cells, or purified macrophages also caused a similar enhancement of DNA synthesis by thymocytes. On the other hand, excess numbers of exudate cells (27 to 28 × 103 of 3-hr exudate cells, or 25 to 29 of 96-hr exudate cells) or excess amounts of culture supernatants (800 µl from 6.4 to 12.8 × 106/4 ml of 3-hr cells, or 200 µl from 12.8 × 106/4 ml, 400 µl from 6.4 × 106/4 ml, or 800 µl from 3.2 × 106/4 ml of 96-hr cells) diminished the enhancing potency on thymocytes. The cooperative function by polymorphonuclear leukocytes or by macrophages on the lymphocyte response was thus postulated.
Cytoplasmic Immunofluorescence of Bone Marrow Plasma Cells Producing Immunoglobulins of the Four IgG Subclasses
Authors: Morell Andreas , Skvaril Frantisek , Hijmans Willy , Scherz Rudolf 
Published: December 2022

Abstract
Immunofluorescence studies were performed on bone marrow samples from 21 individuals with normal or slightly elevated serum IgG levels. On the average, 40.7% of the IgG-positive plasma cells contained molecules of the subclass IgG1; 30.6% had intracellular IgG2; 21.7%, IgG3, and 7.0%, IgG4. These figures were compared to the relative serum IgG subclass concentrations. The principal finding was the discrepancy between the high relative number of IgG3-producing bone marrow plasma cells and the low relative IgG3 serum concentration (5.5% of the total IgG). It was explained by the short biologic half-life of molecules of this subclass.
Concanavalin A Preparations with Activities Related to Bacterial Lipopolysaccharide
Authors: Brunson Kenneth W. , Watson Dennis W. 
Published: December 2022

Abstract
Concanavalin A. (Con A)2 and other plant lectins have recently been extensively employed as biochemical probes in order to investigate cell surfaces and specific binding sites on these surfaces (1–3). Con A is also a potent lymphocyte mitogen (4, 5). In the course of comparative investigations of the mitogenic property of Con A and bacterial mitogens, we found Con A preparations to be pyrogenic. Pyrogenicity of Con A had previously been reported (6); however, the febrile response in American Dutch rabbits we observed was strikingly similar to the biphasic curves obtained upon i.v. injection of Gram-negative bacterial endotoxin (lipopolysaccharide). Moreover, by using dose response relationships of several Con A preparations observed in rabbit pyrogen tests, the pyrogenic activity could be biologically quantitated, as reported for endotoxin (7). An amount necessary for a minimal pyrogenic dose at 3 hr (MPD-3) could thus be determined (7). We therefore felt compelled to investigate further any possible cross-reactive relationships between the Con A preparations and endotoxin.