bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enumeration of IL 2-secreting helper T cells by limiting dilution analysis, and demonstration of unexpectedly high levels of IL 2 production per responding cell.
Authors: Miller R A , Stutman O 
Published: December 2022

Abstract
We describe here a method for estimating the frequency of alloantigen-responsive precursors of interleukin 2-(IL 2) secreting mouse T helper cells in spleen cell populations, and for measuring the amount of IL 2 generated by the progeny of each responsive cell over a 5-day culture period. Depending on the particular stimulus, about 1 T cell in every 30 to 300 can generate detectable levels of IL 2. Mls-locus incompatibilities activate a higher fraction of cells than do differences at the H-2 complex. The responder cell is sensitive to anti-Thy-1.2 antibody and complement, and is highly enriched in Lyt-2- populations as compared to positively selected Lyt-2+ cells. The dilution curve obtained is consistent with the idea that IL 2 production depends on a single class of T cell. The amount of IL 2 produced in these limiting dilution cultures is unexpectedly high; about 30-fold greater than the levels predicted by extrapolation from conventional mixed lymphocyte cultures. These results suggest that conventional cultures may be very responsive to regulatory events that do not occur at very low responder cell concentrations. Thus, limiting dilution analyses will provide insights into the effects of drugs, age, subset manipulation, etc., on the IL 2-producing cell itself, information that cannot be provided by conventional methods alone.
Fc receptors for IgE on mouse macrophages and macrophage-like cell lines.
Authors: Boltz-Nitulescu G , Plummer J M , Spiegelberg H L 
Published: December 2022

Abstract
Murine alveolar and peritoneal macrophages (AM phi, PM phi) and M phi-like cultured cell lines were analyzed for IgE Fc receptors by rosette formation with mouse IgE-sensitized red cells and by binding of radiolabeled mouse IgE. A mean of 90.4% AM phi, 56.9% PM phi, 93.4% P388D1, 81.2% J774.1, 15.6% WEHI3, 54.7% WR19M.1, 52.3% RAW264.7, and 19.5% RAW309Cr.1 M phi-like cells formed IgE rosettes. The rosettes were specific for native mouse IgE and were inhibited by mouse IgE but not mouse IgG, IgA, IgM, or heat-denatured mouse IgE. Rat IgE, but not human IgE, induced rosettes and inhibited mouse IgE rosettes. Trypsin treatment of the M phi abolished IgE rosette formation. Mouse IgE bound to P388D1 M phi-like cells with a KA of 7.6 +/- 0.2 X 10(6) M-1 to 3.3 +/- 0.9 X 10(5) binding sites. After 30 min of incubation at 37 degrees C, 30 to 45% of AM phi, P388D1, and J774.1 M phi-like cells ingested erythrocytes sensitized with IgE but not unsensitized erythrocytes. The data indicate that mouse M phi bear Fc receptors specific for IgE that mediate phagocytosis of IgE-sensitized erythrocytes.
Structural and functional characterization of an incompletely processed form of murine C4 and Slp.
Authors: Karp D R , Capra J D , Atkinson J P , Shreffler D C 
Published: December 2022

Abstract
The properties of a 128,000-dalton polypeptide, corresponding to the uncleaved alpha- and gamma- chains of the fourth component of murine complement (C4), were studied. A fragment of similar size (137,000 daltons) from the structurally related sex-limited protein (Slp) was also found. These polypeptides have methylamine and iodoacetamide binding sites. suggesting that they, like the alpha-chains of C4 and Slp, possess an internal thiolester. In tryptic peptide map analysis, extensive homology is seen between the 128,000-dalton fragment and native C4 alpha- and gamma-chains. N-terminal sequences for this fragment and C4 alpha are identical, as are those for the 137,000-dalton Slp fragment and Slp alpha. Although the alpha-gamma fragment, like C4 alpha, undergoes denaturation-dependent autolytic cleavage, unlike C4 alpha, it cannot be cleaved by C1 This indicate that some of the properties of C4 do not require the native three-chain structure, whereas others do require it. These findings suggest that the alpha-gamma fragments represent an intermediate step in the processing of the C4 and Slp precursor polypeptides.
Interaction of very low density lipoproteins (VLDL) with rabbit C-reactive protein.
Authors: Cabana V G , Gewurz H , Siegel J N 
Published: December 2022

Abstract
Rabbit CRP is similar to human CRP in structure, kinetics of appearance, and binding reactivities to phosphate esters and cationic polymers. CRP in rabbit acute-phase serum migrates either with gamma or with beta, pre-beta electrophoretic mobility, and distinct gamma- and beta-migrating species can be observed simultaneously in some sera. The present study shows that beta-CRP in serum is converted to gamma mobility during isolation and purification. Normal, acute-phase, or CRP-depleted acute-phase rabbit serum restores the beta mobility of purified gamma-CRP, a conversion that does not occur in the presence of EDTA. Serum CRP fails to adsorb to DEAE-cellulose but does adsorb to CM-cellulose, from which it elutes as gamma-mobility antigen. Chelation by EDTA or flotation and removal of lipoproteins from acute phase rabbit serum produces a gamma-mobility CRP that adsorbs to the anion-exchange resin. Lipid-containing fractions from ion-exchange columns as well as VLDL (but not LDL or HDL) isolated by ultracentrifugation change the mobility of purified CRP from gamma to beta, pre-beta. These changes in mobility are not observed in the presence of EDTA or phosphocholine. In acute-phase rabbit serum with CRP of both beta and gamma mobility, the beta form has a higher m.w. and is lipid-associated, whereas the gamma form is a lower m.w., lipid-poor molecule. These results suggest that in serum the association of CRP with lipoproteins, particularly VLDL, is responsible for its beta, pre-beta electrophoretic mobility. Further studies of the association of CRP with lipoprotein in relation to lipoprotein metabolism may provide insight into the biological role of CRP.
IgA-producing hybridomas are readily derived from gut-associated lymphoid tissue.
Authors: Komisar J L , Fuhrman J A , Cebra J J 
Published: December 2022

Abstract
Eight hybridomas secreting IgA monoclonal antibodies were obtained by using gut-associated lymphoid tissue as a primed plasmablast source. IgA secretors are obtained at higher frequencies by this technique than by conventional splenic fusions. This technique provides useful tools for the study of mucosal protection, and it demonstrates that exaggerated potential of gut-derived B cells, compared to splenic B cells, for IgA expression.
Inhibition of specific immune responses by feeding protein antigens. V. Induction of the tolerant state in the absence of specific suppressor T cells.
Authors: Hanson D G , Miller S D 
Published: December 2022

Abstract
The effect of CY pretreatment on the ability of OVA feeding to induce both tolerance and active suppression was examined in mice. CY-pretreated, OVA fed mice were fully unresponsive in both OVA-specific DTH and antibody responses, but, in contrast to untreated OVA-fed mice, did not transfer suppression to normal recipients via splenic lymphocytes. Restoration of Ts activity in CY-pretreated mice was accomplished by reconstitution with normal T cells before antigen feeding, indicating that the CY effect was at the Ts precursor level. In addition, it was found that certain OVA-specific immune parameters (DTH and splenic PFC responses) in recipient mice were susceptible to suppression by transfer of spleen cells from OVA-fed donors, whereas other measures (antigen-induced T cell proliferation and serum antibody titers) were not. The data suggest that CY-sensitive Ts are not necessary for either induction or maintenance of specific tolerance after OVA feeding.
Induction of immunoglobulin secretion by a simple nucleoside derivative.
Authors: Goodman M G , Weigle W O 
Published: December 2022

Abstract
8 bromoguanosine (8BrGuo), a low m.w. nucleoside derivative that rapidly traverses the lymphocyte membrane to the interior of the cell, is an extremely potent inducer of immunoglobulin production by B lymphocytes. It has recently been demonstrated that this same agent can initiate high level lymphocyte proliferation in vitro. Data in the current report demonstrate that 8Br-cGMP and other cGMP analogues are at best weak inducers of immunoglobulin secretion, being more than two orders of magnitude less effective (per molecule taken up) than 8BrGuo. Incubation of lymphocytes with 8BrGuo fails to elevate their intracellular concentrations of cGMP. Moreover, at equimolar concentrations, underivatized cGMP actually antagonized the induction of antibody production by 8BrGuo. These data, in concert with observations that many lymphocyte activators fail to alter cGMP content, that many agents that elevate cGMP fail to induce immunoglobulin synthesis, and that some cGMP-elevating agents even inhibit it, suggest that the induction of immunoglobulin production, like the induction of proliferation in B cells, is not primarily dependent upon cGMP. A simple nucleoside derivative is described, the use of which should prove to be a powerful probe for investigating the triggering mechanisms underlying the proliferative and differentiative B lymphocyte pathways at the molecular level.
T cell regulation of the IgG2a response to TNP-Ficoll: evidence that allotype congenic mice contain both helper cells that preferentially enhance IgG2a synthesis and suppressor cells that specifically suppress IgG2 synthesis.
Authors: Mongini P K , Paul W E 
Published: December 2022

Abstract
When unprimed C57BL T cells were transferred into C57BL nu/nu mice, a preferential enhancement of the IgG2a antibody response to TNP-Ficoll was observed. Unprimed splenic T cells from Igh allotype congenic (B.C8) mice were unable to enhance the IgG2a response. The failure of T cells from allotype congenic mice to augment IgG2a antibody production to TNP-Ficoll was due to the presence of a T cell that specifically suppressed IgG2a antibody synthesis. The suppressive activity could be demonstrated in nu/nu mice and nu/nu mice reconstituted with C57BL helper cells. The suppressive activity of the B.C8 T cell population could be abrogated by treatment with anti-Lyt-1 and anti-Lyt-2 antibodies and complement as well as by treatment of B.C8 T cells with anti-Lyt-2 alone. Removal of the T cells responsible for IgG2a suppression from B.C8 splenic T cell population unmasked a population of B.C8 T cells that could enhance IgG2a preferentially augment IgG2a antibody synthesis can be found in donor mice that differ in their Igh background from the responding B cells.
Asymmetrical surface IgG on MOPC-21 plasmacytoma cells contains membrane heavy chain and one secretory heavy chain.
Authors: Goding J W 
Published: December 2022

Abstract
Membrane proteins from the B lymphomas WEHI-231 and 2PK3 and from the plasmacytomas MPC-11 and MOPC-21 were radioiodinated in situ by the lactoperoxidase method and were subjected to two-dimensional (nonreduced, reduced) polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Few heavily labeled membrane proteins were composed of disulfide-bonded subunits. One such protein (m.w. 200,000 intact and 116,000 reduced) shared some properties with the PC-1 alloantigen, although it was not conclusively identified. A second major disulfide-bonded protein (m.w. 200,000 intact and 95,000 reduced) has been identified previously as the receptor for transferrin. Membrane immunoglobulins of WEHI-231 (IgM) and 2PK3 (IgG2a) had the expected subunit structure, whereas membrane immunoglobulin was not detected on MPC-11. In contrast, surface IgG1 of MOPC-21 appeared to consist almost entirely of hybrid molecules containing one membrane gamma 1 chain and one secretory gamma 1 chain. This hybrid IgG molecule appeared to exist in both monomeric and dimeric forms. It is concluded that i) the synthetic and assembly mechanisms of secretory and membrane IgG1 are shared; ii) there are no special mechanisms to prevent pairing of membrane and secretory gamma 1 chains; iii) the presence of one hydrophobic tail is sufficient for membrane insertion of gamma 1 chains; and iv) the C-terminal extension cysteine residues of membrane gamma 1 chains in hybrid IgG molecules are either unpaired or may allow the formation of hybrid IgG dimers.
Opsonic properties of C-reactive protein in vivo.
Authors: Nakayama S , Mold C , Gewurz H , du Clos T W 
Published: December 2022

Abstract
The capacity of CRP to alter the clearance and site of sequestration of erythrocytes was examined. Mouse erythrocytes, coated with PnC to provide a binding site for CRP, were radiolabeled and injected into homologous mice. The liver, spleen, kidneys, and lungs were removed and counted to assess the site of erythrocyte clearance. In the presence of CRP, an increase in splenic sequestration of E-PnC was observed along with a slight decrease in hepatic sequestration. This altered clearance pattern was dependent on both C activation and on the continued presence of CRP. The clearance of cells coated with IgM or IgG antibody to PnC was compared. In both cases, antibody caused an increase in sequestration by the spleen. However, IgM-coated cells required C for splenic clearance, whereas IgG-coated cells did not. We have shown in these experiments that CRP can affect the in vivo pattern of organ sequestration of cells to which it is bound in a manner similar to antibody.
Functional heterogeneity of culture-grown bone marrow-derived macrophages. II. Lymphokine stimulation of antigen-presenting function.
Authors: Lee K C , Wong M 
Published: December 2022

Abstract
The activation of immunostimulatory activity and Ia expression was studied in pure populations of murine macrophages (M phi) grown in vitro from bone marrow precursor cells in the presence of L cell-conditioned medium as the source of colony-stimulating factor. During exponential growth, the M phi developed maximal Ia-dependent antigen-presenting activity as detected by the induction of antigen-specific T cell proliferation, but the proportion of Ia+ M phi was low (less than 10%). Fractionation of the M phi according to size by velocity sedimentation resulted in concentration of the antigen-presenting cells in the smallest fraction, but the enrichment of Ia+ M phi in this fraction was less than twofold. All fractions also showed comparable degrees of antigen uptake regardless of their T cell-stimulating activity. Thus Ia and antigen, although obviously essential, are insufficient for full manifestation of antigen-presenting function. Activation of M phi with lymphokines from Mycobacterium-activated lymph node cells resulted in enhanced Ia expression in all fractions, but only small M phi showed an enhancement in antigen presentation. Large activation M phi were found to exert an immunosuppressive effect that probably neutralized any augmentation of stimulatory activity. thus heterogeneity can be demonstrated in i) the function of unstimulated M phi, ii) the responsiveness of subsets to stimulation, and iii) the manifestation of activated functions.
Fc gamma 2b receptor-mediated prostaglandin synthesis by a murine macrophage cell line (P388D1).
Authors: Nitta T , Suzuki T 
Published: December 2022

Abstract
The nature of signals transmitted by two types of Fc gamma receptors (one specific for IgG2b and the other for IgG2a) present on the surface of a murine macrophage cell line (P388D1) was investigated. Specific binding of IgG2b (presented as EA2b) to cell surface Fc gamma 2br triggered the release of 3H-arachidonic acid and 3H-prostaglandins (PG) from P388D1 cells that were prelabeled with 3H-arachidonate. The release of 3H-arachidonic acid, which increased in a dose-dependent manner, was enhanced by exogenous Ca++ (1.25 mM) and was completely blocked by ethylenediaminetetraacetate (EDTA) (4 mM) or a phospholipase A2 inhibitor, p-bromophenacylbromide (7 microgram/ml). A cyclooxygenase inhibitor, indomethacin (9 microgram/ml), reduced the 3H-arachidonic acid release and completely blocked the conversion of arachidonate into PG. Cytochalasin D (1 microgram/ml), which inhibited the phagocytosis of immune complexes by 90% of P388D1 cells, did not affect the Fc gamma 2bR-triggered release of arachidonic acid. Specific binding of IgG2a (presented as EA2a) to cell surface Fc gamma 2aR did not trigger the release of either 3H-arachidonic acid or 3H-PG from P388D1 cells. Our data demonstrate a signal for the activation of the arachidonic acid metabolic cascade is transmitted by Fc gamma 2bR, but not by Fc gamma 2aR, on the surface of P388D1 cells, probably through the initial activation of the phospholipase A2 activity associated with Fc gamma 2bR.
Tubulointerstitial nephritis and immunologic responses to Tamm-Horsfall protein in rabbits challenged with homologous urine or Tamm-Horsfall protein.
Authors: Mayrer A R , Kashgarian M , Ruddle N H , Marier R , Hodson C J , Richards F F , Andriole V T 
Published: December 2022

Abstract
Tubulointerstitial nephritis was produced in 19 of 23 New Zealand White rabbits challenged i.v. with adjuvant-free homologous urine for greater than or equal to 16 wk and 11 of 14 challenged with adjuvant-free rabbit Tamm-Horsfall protein for 2 to 24 wk. Lesions were identical in the two groups of rabbits and were characterized by focal mononuclear infiltrates and microscopic scarring localized to distal nephron segments identified as the thick ascending limb of the loop of Henle. Concomitant immunoglobulin deposition was not detected despite antecedent elevations in serum IgG antibody directed against Tamm-Horsfall protein in 17 of 19 and 10 of 11 affected rabbits, respectively. Peripheral lymphocytes from affected rabbits were found to be cytotoxic and underwent blast transformation in the presence of homologous urine or Tamm-Horsfall protein in vitro. These lymphocytes were shown to produce a soluble cytotoxic product upon exposure to Tamm-Horsfall protein. Neither tubulointerstitial nephritis nor this pattern of cellular and humoral immune response to Tamm-Horsfall protein was found in two age-matched control groups: one unchallenged, and the other challenged i.v. with urine that had been selectively depleted of Tamm-Horsfall protein by 95%. It is concluded that the tubulointerstitial nephritis produced in rabbits by injection of urine or Tamm-Horsfall protein is the result of a predominately cellular immune response directed against Tamm-Horsfall protein.
Human T cell hybridomas producing lymphokines. I. Establishment and characterization of human T cell hybridomas producing lymphotoxin and migration inhibitory factor.
Authors: Kobayashi Y , Asada M , Higuchi M , Osawa T 
Published: December 2022

Abstract
Stable human T cell hybridomas were produced by cell fusion between PHA-activated human peripheral blood lymphocytes and human acute lymphatic leukemia cells of a CEM cell line whose proliferation had been inhibited by treatment with an irreversible protein synthesis inhibitor (emetine) and an irreversible RNA synthesis inhibitor (actinomycin D). Two hybrid cell lines (E10, F8) thus produced expressed OKT3-reactive antigen, HLA-A1 and -B8 antigens derived from CEM cells, and HLA-A2 antigen derived from PBL, and they have 10 more chromosomes than CEM cells. Furthermore, these cell lines continuously secreted lymphotoxin over 3 mo. E10 was found to produce MIF in addition to lymphotoxin. Cloning of E10 and the relationship between the functions and surface phenotypes of E10 sublines were examined. Lymphotoxin-producing hybrids (E10-15 and E10-37) express more OKT8-reactive antigen than OKT4-reactive antigen, while lymphotoxin and MIF-producing hybrids (E10-25, E10-42, and E10-43) express more OKT4-reactive antigen than OKT8-reactive antigen.
Effects of oxygen radical scavengers and antioxidants on phagocyte-induced mutagenesis.
Authors: Weitzman S A , Stossel T P 
Published: December 2022

Abstract
Phagocytic leukocytes from normal humans can produce mutations in bacteria. To define further the role of oxygen radicals in this mutagenic process, we performed experiments in which scavengers or antioxidants were added to the incubation of phagocytes and bacteria. We found that 1) superoxide dismutase, catalase, mannitol, and benzoate were all capable of inhibiting mutation, 2) sulfhydryl compounds and vitamin E were also inhibitory, and 3) the presence of vitamin C in the incubations increased the mutation frequency. These data suggest an important role for hydroxyl radicals in mediating phagocyte-induced mutations.
I-A antigens on cloned alloreactive murine T lymphocytes are acquired passively.
Authors: Lorber M I , Loken M R , Stall A M , Fitch F W 
Published: December 2022

Abstract
Cloned lines of alloreactive cytolytic and amplifier T lymphocytes have been examined for expression of I-A antigens. Using flow cytofluorometry and monoclonal antibodies, MHC antigens representing both I-A and H-2K or D determinants were reproducibly detected on the cell surface of these cloned T lymphocytes. All cloned lines examined expressed H-2K or D antigens representing the MHC haplotype appropriate to their strain of origin. However, I-A as well as H-2K or D antigens appeared to be acquired passively from the stimulating cell population. Within the lower limits of detection using the fluorescence-activated cell sorter, evidence suggesting endogenous synthesis of I-A antigens by these cloned T lymphocytes could not be demonstrated. Further, the observed binding appeared to be nonspecific, because material originating from allogeneic, syngeneic, or third-party stimulating cells could be observed under appropriate conditions.
A monoclonal antibody directed against the HLA-Bw6 epitope.
Authors: Radka S F , Kostyu D D , Amos D B 
Published: December 2022

Abstract
A cytotoxic monoclonal antibody, SFR8-B6, produced by immunizing KGH rats with partially purified glycoprotein from JY, a human B lymphoblastoid cell line, detects HLA-Bw6, a unique public antigen on the HLA-B molecule. By cytotoxicity, SFR8-B6 has complete concordance with the presence of Bw6 as defined by alloantisera, and its reactivity segregates with HLA in families. Because sera detecting Bw4 and Bw6 are rare, this monoclonal antibody has value as a perpetual standard. In addition, SFR8-B6 offers potential as a probe for investigating the molecular relationships of HLA antigens.
Effect of plicatic acid on human serum complement includes interference with C1 inhibitor function.
Authors: Giclas P C 
Published: December 2022

Abstract
In an earlier study, we presented evidence that plicatic acid (PA) activated C in normal human serum (NHS) by an immunoglobulin-independent mechanism that did not involve factor B of the alternative pathway and that required Ca++ for initiation. The present paper further verifies that PA acts through the classical pathway. In PA-treated NHS, titers of C1, C4, C3, and C5 decreased after incubation at 37 degrees C, but in C2-deficient serum, only the titers of C1 and C4 were decreased after identical PA treatment. Activation of purified precursor C1 did not occur when it was incubated with PA at concentrations that would have produced C1 consumption in serum. Thus, PA added to serum initiates activation of the classical pathway, but is incapable of activating C1 directly. PA added to a mixture of native C4 and activated C1s did not alter the kinetics or the extent of C4 inactivation by the C1s. However, when mixtures of C4, C1s, and C1-In were incubated with PA, the ability of the inhibitor to inactivate the C1s was markedly reduced. These data indicate that the mechanism by which PA activates C in serum may involve interference with the normal regulatory mechanism that controls C1 activity.