bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Reaction of Sle Antibodies with Native, Single Stranded Rna: Radioassay and Binding Specificities
Authors: Eilat Dan , Steinberg Alfred D. , Schechter Alan N. 
Published: December 2022

Abstract
Escherichia coli 3H-tRNA and MS2 phage 125I-RNA were prepared and used in a sensitive nitrocellulose filter assay. Antibodies that bound these RNA ligands occurred in the sera of several patients with SLE, but not in sera of patients with other connective tissue diseases. The antibody populations that bound polyribonucleotides (largely IgG) were distinct from antibody populations that bound polydeoxyribonucleotides. Competition experiments showed that the anti-RNA antibodies preferentially bound native ssRNA as compared with synthetic single and double stranded polyribonucleotides. There was increasing affinity with increasing m.w. of the ssRNA. The anti-tRNA population was of restricted heterogeneity (Sips index 0.83) and bound tRNA with an average association constant (Ko) of 9 × 106 1/mole at 4°C. The anti-MS2 RNA population was much more heterogeneous (Sips index 0.67) and bound MS2 RNA with a Ko of about 3 × 109 1/mole at 4°C. Whereas NZB/NZW mice spontaneously produce RNA reactive antibodies with conformation specificity for native tRNA, human SLE anti-RNA antibodies appear to have very little of this type of conformation specificity.
Detection of Ia Antigens on Langerhans Cells in Guinea Pig Skin
Authors: Stingl Georg , Katz Stephen I. , Shevach Ethan M. , Wolff-Schreiner Elisabeth , Green Ira 
Published: December 2022

Abstract
Langerhans cells (LC) constitute a small proportion of the mammalian epidermal cells and may be identified by their unique ultrastructural appearance. Of all the cells in the guinea pig epidermis, only Langerhans cells—as defined by ultrastructural criteria—form rosettes with IgG antibody-coated BRBC. Using this rosette assay for the identification of LC and an indirect immunofluorescent technique with FITC-SPA as a marker to detect antigens of the guinea pig MHC, we have investigated whether guinea pig LC bear Ia antigens. Rosette-forming epidermal cells (RF-EC)—identical to LC—from strain 2 animals bound only an anti-strain 2 antiserum, but not an anti-strain 13 antiserum or NGPS and, in reverse fashion, RF-EC from strain 13 animals bound an anti-strain 13 antiserum, but not an anti-strain 2 antiserum or NGPS. LC from (2 × 13)F1 animals reacted with both an anti-strain 2 and anti-strain 13 antiserum, but not with NGPS. Non-RF-EC did not bind any of the anti-Ia antisera. An anti-B.1 antiserum, by contrast, reacted with all epidermal cells from strain 2, strain 13, and (2 × 13)F1 animals (known to share in common B.1 antigens), but not with epidermal cells from a B.3 animal. These results demonstrate that Ia antigens in guinea pig epidermis are selectively expressed on LC, whereas GPLA-B region antigens can be detected on all epidermal cells. Fc-IgG rosette formation by LC can be inhibited by either the specific anti-Ia antiserum or by specific anti-B region antisera, which seems to indicate that antibodies against various antigenic determinants on LC may provoke subtle membrane changes resulting in Fc receptor blockade.
The finding of Fc receptors along with the expression of Ia antigens on the surface of LC supports the concept of their being involved in the afferent limb of the immune response.
Identification of a Tumor-Associated Antigen of the Guinea Pig L2C Leukemia by Using Syngeneic Antisera
Authors: Hu Cheng-Po , Schwartz Benjamin D. , Green Ira 
Published: December 2022

Abstract
Inbred strain 2 guinea pigs immunized with L2C leukemia cells produced antibodies to L2C cells detected by 125I-protein A assay. L2C-associated tumor antigens were reacted with syngeneic antisera and analyzed by immunoprecipitation and SDS-polyacrylamide gel electrophoresis. These sera recognized idiotypic determinants on surface IgM molecules of L2C cells but did not recognize any determinants on normal strain 2 spleen cells. Thus, determinants on IgM molecules act as tumor-associated antigens in the L2C system and can be detected by syngeneic sera.
Suppression of Experimental Allergic Encephalomyelitis by 6-Hydroxyphthalaldehydic Acid, O-(p-Chlorobenzyl)Oxime (EN3638)
Authors: Levine Seymour , Sowinski Richard 
Published: December 2022

Abstract
EN3638 is a new oxime derivative of salicylic acid that has immunosuppressive properties. Oral administration of the compound to rats during the incubation period of experimental allergic encephalomyelitis (EAE) delayed the onset of clinical signs. EN3638 was effective in both ordinary and hyperacute forms of EAE. Doses of 50, 100, or 150 mg/kg daily, 250 mg/kg three times a week, or 400 mg/kg twice a week suppressed both clinical and histologic evidences of EAE during the course of therapy (as long as 4 weeks) and for 8 or more days thereafter. Clinical EAE developed after a full incubation period after discontinuance of EN3638, probably due to the persisting depot of antigen in oil. When EAE was produced without an oily depot, a single dose suppressed the disease for at least 5 weeks in some rats. EN3638 was effective when given only in the second half of the incubation period but not when given at the time that EAE lesions and signs develop. Passive transfer experiments suggested that the drug prevented and even reversed sensitization to neural antigens. It had only slight effect on fully sensitized lymphoid cells or on the recruitment of nonimmune inflammatory cells in the nervous system, and it was not acting as a source of salicylate or as an adrenocortical stimulator.
Thymus Dependency of Host Resistance to Giardia Muris Infection: Studies in Nude Mice
Authors: Stevens David P. , Frank Dorothy M. , Mahmoud Adel A. F. 
Published: December 2022

Abstract
Infection of normal mice by the intestinal protozoan Giardia muris is self-limited and is followed by resistance to subsequent reinfection (1, 2). Similar observations have been made in G. lamblia infection in limited studies in human volunteers (3). The nature and mechanism of this parasite elimination are, however, unclear. Immune mechanisms may be suspected in human infection with G. lamblia because of the high prevalence of chronic giardiasis in persons with variable immune deficiency syndrome (4). Congenitally hypothymic (nude, nu/nu) mice provide a useful model to test the contribution of thymus-dependent immune mechanisms in resolution of this protozoan infection. We have previously described the natural history of G. muris infection in mice (1). The infection can be measured by counting trophozoites in small intestine and cysts in feces; peak fecal cyst excretion occurs 1 to 2 weeks after oral inoculation of cysts in CF-1 outbred mice and in A/J and BALB/c inbred strains followed consistently by resolution of infection in 4 to 7 weeks (1, 2).
T Lymphocyte-Mediated Cytolysis: Dissociation of the Binding and Lytic Mechanisms of the Effector Cell
Authors: Fishelson Zvi , Berke Gideon 
Published: December 2022

Abstract
To determine functional relationships between the cytotoxic T lymphocyte (CTL) receptor for target binding and the lytic mechanism, we have studied the reaction between two immunized CTL populations (AαB and BαA), both at the population and the single-cell level. When studied at the population level, the reaction of AαB with BαA (bidirectional system) resulted in formation of AαB/BαA conjugates and bidirectional cytolysis. However, when the viability of cells in individual AαB/BαA conjugates was analyzed, unidirectional instead of bidirectional lysis occurred. These results indicate that under conditions that are conducive to lysis, binding of a potentially lytic cell to its target does not necessarily result in target lysis. Short heat treatment of CTL (44°C, 10 min) totally abolished their lytic activity, without affecting their capacity to bind specifically, thus dissociating the binding from the lytic activity of the CTL. The cytolytic activity is probably associated with, or triggered by the CTL-binding unit. The binding unit, on the other hand, appears to be a functional receptor of the CTL, which is involved in but not sufficient to bring about lysis.
Separation of Helper and Suppressor T Lymphocytes
Authors: Tse Harley Y. , Dutton Richard W. 
Published: December 2022

Abstract
Using a Ficoll velocity sedimentation gradient, we provide evidence to show that stimulatory and inhibitory activities induced in mixed lymphocyte culture belong to two distinct subpopulations of T cells. Slow- to medium-sedimenting, nonproliferating cells enhance the humoral response of normal cells to SRBC whereas fast-sedimenting cells inhibit that response. Cytotoxic lymphocytes are found in the same fractions as suppressor cells but appear to be differentiable from the latter in terms of maturation kinetics and specificity
Effects of Vitamin B6 Deficiency on Thymic Epithelial Cells and T Lymphocyte Differentiation
Authors: Willis-Carr J. I. , St. Pierre R. L. 
Published: December 2022

Abstract
Dietary vitamin B6 (pyridoxine) deficiency in young Lewis rats results in a reduction of T lymphocyte numbers and defects of cellular immunocompetence. In vitro studies of thymic epithelial (TE) cells, responsible for inducing T lymphocyte differentiation, revealed that maintenance on a vitamin B6 deficient diet for 2 weeks resulted in a severe defect in TE cell function. When the deficient animals were returned to a normal diet, TE cell function was restored. Exposure of lymphoid precursors from neonatally thymectomized or vitamin B6-deficient donors to normal TE monolayers resulted in their conversion to functional T lymphocytes, as measured by their response in MLR and to mitogens. However, TE monolayers from vitamin B6-deficient animals were unable to effect such a maturation of T lymphocytes. Therefore, it is suggested that the defect in cellular immunocompetence following this dietary deficiency is due, at least in part, to the inability of TE cells to effect the differentiation of T lymphocyte precursors to functional T lymphocytes. The dietary deficiency does not, however, impair lymphoid precursors, which can be stimulated to further differentiation by exposure to normal TE cell monolayers.
Characterization of a Soluble Factor that Specifically Suppresses the in Vitro Generation of Cells Cytotoxic for Syngeneic Tumor Cells in Mice
Authors: Takei Fumio , Levy Julia G. , Kilburn Douglas G. 
Published: December 2022

Abstract
A tumor-specific soluble factor found in extracts of thymocytes from mice bearing small P815 tumors has been demonstrated. This factor is capable of significantly suppressing the in vitro generation of syngeneic cells cytotoxic for P815 targets if it is added to culture vessels within the first 30 hr of culture. The suppressive factor eluted from Sephadex G-100 after hemoglobin and was estimated to have a m.w. in the range of 40 to 60,000. Preparative isoelectric focusing of thymic extracts established that the suppressive material has an isoelectric point in the range of pH 4.6 to 4.9. The suppressive activity of extracts could be removed by passage of the material through immunoadsorbent columns prepared from membrane proteins of P815 cells but not by analogous columns prepared by using L1210 membrane proteins. The suppressive material was not removed by its passage through immunoadsorbent columns containing anti-mouse immunoglobulin.
Immune Responses During Human Schistosomiasis Mansoni
Authors: Colley Daniel G. , Lewis Fred A. , Goodgame Richard W. 
Published: December 2022

Abstract
Human peripheral blood lymphocytes from patients with chronic Schistosoma mansoni infection were exposed to concanavalin A (Con A), soluble schistosome egg antigenic preparation (SEA), or soluble adult worm antigenic preparation (SWAP). They were then evaluated for their ability to suppress the phytohemagglutinin response of autologous cells. Significant suppression was reliably obtained by Con A pretreatment of the cells of 15 of 17 patients (88%). Pre-exposure of patient's cells to SEA and SWAP in medium supplemented with normal human serum (NHS) resulted in significant suppression being expressed by 36% and 39% of the patients, respectively. The ability to express suppressor activity in these circumstances did not appear to correlate with the intensity of the patient's S. mansoni infection, or the clinical state of the patient's disease. The capacity to generate schistosomal antigen-induced suppressor activity increased sharply during the second decade of life, in general, correlating with increased duration of infection. Preliminary studies have indicated that the ability to generate schistosome antigen-induced suppressor activity was greatly increased when the cells were exposed to the antigens in the presence of “suppressive” sera from a patient with chronic S. mansoni infection rather than NHS. This information suggests a synergistic relationship, involving antigenic exposure of both the cells and sera of certain chronic patients, which assists in the induction of suppressor activity. The immunoregulatory responses observed could be important in the establishment of a stable chronic infection state by modulating the extent of egg-induced granuloma formation and preventing rejection of the adult worm.
A Two-Step Centrifugation Procedure for the Purification of Sheep Erythrocyte Antigen-Binding Cells
Authors: Kenny James J. , Merrill Jean E. , Ashman Robert F. 
Published: December 2022

Abstract
A two-step centrifugation procedure has been developed to isolate greater quantities of highly purified sheep erythrocyte antigen-binding cells (ABC) than previously possible. The first step involves partially separating sheep erythrocyte rosettes from unrosetted lymphocytes by their difference in buoyant density on Ficoll-Hypaque. Subsequent passage through a linear 5 to 10% Ficoll gradient produces further purification of rosettes by sedimentation velocity. Approximately 4.5 × 106 ABC can be obtained at 50 to 100% purity from 109 immune spleen cells (5 days post-immunization) and 1 × 105 ABC at 20 to 40% purity from 109 nonimmune spleen cells. The purified ABC from 5-day immune animals are 80 to 90% B cells and 10 to 20% T cells, and represent between 30 and 40% of the original ABC in the spleen cell population. Less than 0.2% of the purified ABC are plaque-forming cells (PFC) and less than 2% have intracellular immunoglobulin (Ig) or J chain. The quantities of ABC obtained are sufficient for investigating biochemical parameters of antigen-induced lymphocyte activation and for direct analysis of the surface isotypes found on antigen-binding cells after immunization.
Increase of T Lymphocyte Self-Reactivity in Aging Inbred Rats: In Vitro Studies with a Model of Experimental Autoimmune Orchitis
Authors: Kyewski Bruno , Wekerle Hartmut 
Published: December 2022

Abstract
To study the self-reactivity of rat lymphocytes as a function of age we applied an in vitro correlate of the experimental autoimmune orchitis (EAO). Previous analyses indicated that in this in vitro model, T lymphocytes react specifically against autoantigens when cocultured with syngeneic testis cells. The EAO response shows tissue specificity and is determined by the MHC. The self-reaction is measured in a cytostasis microassay, which is based on estimating growth inhibition of testis cell-derived monolayer formation in a terminal 51Cr uptake assay. We compared the self-reactivity of individual rats of varying ages (3 to 26 months) by testing their in vitro EAO responsiveness. In parallel, their reactivity to alloantigens and a polyclonal T lymphocyte activator (Con A) was monitored. We found a decrease in the allo- and the mitogen responsiveness in aged animals (from 20 months on) compared to young controls (3 months). The self-reactivity, in contrast, was in all cases increased. The increased EAO response was found not to be due to age-dependent alteration of the relevant autoantigens nor to changed functions of accessory non-T cells. The enhanced autoimmune reactivity was rather a property of the T cell compartment. We believe that these results indicate an age-dependent loss of T lymphocyte self-tolerance, which may play an active role in the pathogenesis of autoimmune diseases in the aging organism.
The Central Nervous System-Associated Immune Response to Parainfluenza Type I Virus in Mice
Authors: Gerhard Walter , Iwasaki Yuzo , Koprowski Hilary 
Published: December 2022

Abstract
The immune response in the cerebrospinal fluid (CSF) and serum of BALB/c mice was compared after intracerebral (i.c.) inoculation with inactivated parainfluenza type 1 virus. The antiviral antibody response in CSF peaked approximately 11 days after primary i.c. inoculation coinciding with or even slightly preceding the response in the serum. Prior extracerebral priming of the mice by the intranasal or i.v. route did not alter the kinetics of the response in CSF. However, the antibody response in CSF after i.c. inoculation was accelerated if the mice were primed previously by the i.c. route. In all instances, CSF and serum differed markedly with regard to the isotype composition, which was characterized by a 20- to 80-fold increase in IgA over IgG1 and IgG2 in CSF.
Taken together, the results prove that part of the antiviral antibodies in CSF are locally produced. In addition, the results indicate that after primary i.c. inoculation with virus, the CNS acquired immunocompetence with regard to the secondary anti-parainfluenza response.
Studies on the Mitogen Responses of Germfree Allogeneic Chimeras
Authors: Mattingly Jerome A. , Webb Phyllis M. 
Published: December 2022

Abstract
Germfree allogeneic bone marrow chimeras (ABMC) were produced by the i.v. injection of approximately 107 bone marrow cells from germfree DBA/2 mice into lethally irradiated germfree C3H mice. In the germfree state, the short-term ABMC showed no histologic signs of graft-vs-host reactions (GVHR), yet splenic lymphocytes were unable to respond to PHA, Con A, or SRBC. Attempts to remove nonspecific suppressor cells by the glass adherence technique failed to improve responsiveness. Attempts to improve responsiveness by the implantation of a DBA/2 thymus under the host kidney capsule also resulted in failure. However, when the donor thymus was enclosed in a cell-impermeable chamber to eliminate a GVH reaction, responsiveness to Con A was restored. The PHA and SRBC responses were unaffected by this treatment. Daily injections of thymosin caused both an increased Con A response and increased numbers of PFC, although the PHA response was again unaffected. Thus, soluble substances from thymic tissue can be used to overcome partially the histocompatibility barrier present in the ABMC that affects at least two different functional cell populations.
Characterization of Murine Colony-Forming B Cells
Authors: Kincade Paul W. , Paige Christopher J. , E. Parkhouse R. Michael , Lee Grace 
Published: December 2022

Abstract
With appropriate culture conditions, numbers of proliferating foci are a linear function of the number of B cells placed in mitogen-stimulated semisolid cultures, and colony formation is not obviously suppressed or enhanced by T cells. This made it possible to determine the fraction of Ig+ B cells in different tissues and stages of development which was capable of colony formation. No evidence was obtained that these functional cells were enriched among either mature or immature B cell populations. Cytolysis with A.TH anti-A.TL serum and C before culture was used to study expression of Ia antigens on colony-forming cells. By this criterion, multipotential stem cells, granulocyte-macrophage progenitors, and fetal colony-forming B cells were Ia negative, whereas all clonable B cells in adult tissues were Ia positive. Colony formation by adult lymph node cells was inhibited by an average of 79% by the addition of rabbit anti-mouse IgD to the cultures, and extremely small quantities of antiserum were required. Adult spleen and bone marrow contained a higher percentage of antiserum-resistant and presumably δ- B cells, and clonable B cells in fetal tissues were not significantly inhibited. An additional subpopulation of late appearing B cells whose proliferation was resistant to anti-Ig antibodies was identified with a particular set of culture conditions. Colony-forming cells were also heterogeneous in their resistance to preincubation with anti-immunoglobulin antibodies. Under conditions that did not significantly affect adult splenic B cells, clonable cells in fetal and neonatal tissues were substantially inactivated. It appears that colony-forming B cells comprise an equivalent proportion of the B cells in different sites and stages of development and include cells that differ in maturity by the criteria employed here. However, they do not seem to be representative of B cells as a whole, and when considered in relationship to the defect in CBA/N mice, the possibility emerges that the cloning technique preferentially detects a lineage of functionally specialized B cells.
Complement (C3)-Activated Phagocytosis by Lung Macrophages
Authors: Shurin Susan B. , Stossel Thomas P. 
Published: December 2022

Abstract
We have investigated the interaction between rabbit lung macrophages and Escherichia coli lipopolysaccharide-coated oil droplets opsonized with a fragment of C3, and of albumin-coated oil droplets opsonized with anti-albumin IgG.
We also examined in detail C3-dependent, IgG-activated, and nonspecific phagocytosis by trypsinized rabbit lung macrophages. We found that: 1) there was no basal ingestion of the LPS particles by macrophages, and reaction of particles with heated serum or anti-LPS antibody failed to elicit ingestion. Only fresh serum (deposition of C3) caused LPS particles to be ingested by macrophages. C3 alone, therefore, is the activator of phagocytosis in this system. 2) The ingestion of C3-coated particles occurred at a rapid constant rate for 2 min, followed by a slower constant rate; the ingestion of IgG-coated particles occurred at a single constant rate. 3) The initial rapid phase of C3-mediated ingestion was dependent upon the presence of divalent cations in the incubation medium; the secondary rate of ingestion of C3-coated particles and the ingestion of IgG-coated particles were not dependent on divalent cations. 4) Heated serum, which contains enzymes that destroy opsonically active C3 on particles, diminished the ingestibility of C3-coated particles, but did not alter the biphasic kinetics of the ingestion mechanism. Although heated serum decreased the ingestibility of C3-coated particles by rabbit exudate polymorphonuclear leukocytes more rapidly than by macrophages, the ultimate loss of ingestibility was equivalent for both cell types. 5) Trypsin rapidly diminished, but did not abolish, C3-activated phagocytosis without affecting IgG-activated or nonspecific ingestion. The principal effect of trypsin was to abolish the initial rapid phase of ingestion. 6) After trypsinization, the macrophages could recover trypsin-sensitive functions. Recovery was dependent upon: a) time, 4 hr being required for complete recovery; b) temperature, with recovery occurring at 37°C but not at 0°C; c) exogenous serum protein (serum or albumin); and d) endogenous protein synthesis (cycloheximide inhibited recovery). The role of serum protein was independent of its lipid-carrying capacity. Drugs thought to influence secretion by acting on cytoplasmic microtubules (colchicine) or which inhibit secretion of a macrophage protease (dexamethasone) had no effect on recovery.
C3-mediated ingestion and IgG-mediated ingestion by lung macrophages differ in their kinetic patterns. Trypsin treatment of macrophages and removal of divalent cations from the medium affect C3-mediated ingestion primarily by altering its kinetics. They exert their effects during an initial rapid phase of ingestion which is not seen in IgG-mediated ingestion. The effect of trypsin on macrophages is reversible with time under appropriate conditions.