bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biochemical signals transmitted by Fc gamma receptors: triggering mechanisms of the increased synthesis of adenosine-3',5'-cyclic monophosphate mediated by Fc gamma 2a- and Fc gamma 2b- -receptors of a murine macrophage-like cell line (P388D1).
Authors: Nitta T , Suzuki T 
Published: December 2022

Abstract
The specific binding of IgG2a or IgG2b subclass monoclonal anti-sheep erythrocyte antibodies to P388D1 cell surface Fc gamma 2aR3 or Fc gamma 2bR, respectively, triggered the synthesis of adenosine-3'5'-monophosphate (cAMP) to an approximately same extent by the mechanisms that are apparently unique for each type of Fc gamma Rs. Fc gamma 2aR appeared to trigger directly, upon binding of IgG2a antibodies, the adenylate cyclase system without requiring the participation of guanine nucleotide-binding (G/F) regulatory protein, because the Fc gamma 2aR-triggered cAMP synthesis, which reached maximum within 30 min, was not significantly affected by an uncoupler, Mn++ or by addition of guanosine triphosphate (GTP) analog, 5'-guanylylimidodiphosphate (Gpp(NH)p). In contrast, Fc gamma 2bR appeared to stimulate indirectly the G/F regulatory requiring-adenylate cyclase system by generating prostaglandins, since the cAMP synthesis, which required 90 min to reach plateau after binding of IgG2b to Fc gamma 2bR, was totally suppressed by phospholipase A2 inhibitor (p-bromophenacylbromide) or cyclo-oxygenase inhibitor (indomethacin), partially suppressed by Mn++, and slightly increased by Gpp(NH)p. Furthermore, the inhibition of phagocytic process by cytochalasin D increased cAMP synthesis mediated by Fc gamma 2aR (about 70% at 2 micrograms/ml), but did not affect Fc gamma 2bR-mediated cAMP synthesis. In addition, our data suggested that both Fc gamma 2aR- and Fc gamma 2bR-mediated cAMP synthesis are independent from beta-adrenergic receptor-mediated stimulation of the adenylate cyclase system, since either beta-agonist (isoproterenol) or beta-antagonist (propranolol) did not affect significantly the levels of cAMP produced in response to EA-stimulation.
The antigenic reactivity of small fragments derived from human myelin basic protein peptide 43-88.
Authors: Whitaker J N 
Published: December 2022

Abstract
In an effort to develop immunochemical reagents for detecting small peptides originating from myelin basic protein (BP), the antigenic determinants of fragments from human BP peptide 43-88 were examined. Antisera were produced in nine sheep and forty rabbits immunized with BP, BP peptide 43-88, or a region derived from within or containing a portion of BP peptide 43-88. These included custom synthesized peptides 51-67, 67-80, 74-84, 79-88, and 83-95. Reactivities were assessed by double antibody radioimmunoassay (DA-RIA) using radiolabeled BP or BP peptides. For peptides 74-84, 79-88, and 83-95 it was necessary to synthetically add a terminal tyrosine residue for radioiodination. Antisera to peptides 51-67, 67-80, 74-84, 79-88, and 83-95 showed much greater reactivity with the homologous antigen, with variable, but sometimes no, reactivity against BP or BP peptide 43-88. This was particularly evident in displacement DA-RIA. Of the small peptides, antisera to whole BP reacted best with peptide 83-95, whereas antisera to peptide 43-88 reacted best with peptide 79-88. Placement of the synthetically added tyrosine had a marked influence on the reactivity of BP peptide 79-88: antisera to BP peptide 43-88 reacted much better with radioiodinated tyrosinyl peptide 79-88 than with radioiodinated peptide 79-88-tyrosine. These results indicate that within a region of BP encompassing residues 51 through 95 a number of potential antigenic determinants exist. Some of the determinants on the small peptides represent distinctive conformational determinants or are inaccessible in BP peptide 43-88. The ability to detect small BP peptides by immunoassay necessitates that the identity of the peptide be known and that antibody reagents capable of reacting with the peptide(s) be available.
Inhibitory action of elevated levels of adenosine-3':5' cyclic monophosphate on phagocytosis: effects on macrophage-Trypanosoma cruzi interaction.
Authors: Wirth J J , Kierszenbaum F 
Published: December 2022

Abstract
The effects of agents that elevate intracellular levels of cyclic AMP on the in vitro interaction of mouse peritoneal macrophages with virulent bloodstream forms of a reticulotropic strain of Trypanosoma cruzi were investigated as a part of our efforts to define the requirements for tissue invasion by this intracellular human pathogen. At optimal, non-toxic concentrations, both L-isoproterenol and prostaglandin E1, agents that increase cyclic AMP levels by activating adenylate cyclase via different mechanisms, reduced the uptake by T. cruzi by the macrophages by approximately 30 and 70%, respectively, and also caused a reduction in the numbers of macrophages capable of incorporating the parasites. Similar results were obtained when either theophylline, which increases cyclic AMP levels by inhibiting the catabolic effect of phosphodiesterase activity, was incorporated into the cultures or by direct addition of dibutyryl cyclic AMP. Reductions produced with optimal concentrations of these drugs amounted to approximately 40 to 50%. The present results indicate that binding and uptake of virulent forms of a reticulotropic strain of T. cruzi by macrophages from a susceptible host are under the regulatory influence of cellular cyclic AMP levels.
Delivery of lethal hits by cytotoxic T lymphocytes in multicellular conjugates occurs sequentially but at random times.
Authors: Perelson A S , Bell G I 
Published: December 2022

Abstract
We propose a stochastic model to explain kinetic data on the delivery of lethal hits by cytotoxic T lymphocytes in multicellular conjugates. The comparison of our model with data of Zagury et al. suggests that cytotoxic T cells deliver lethal hits at random, and when conjugated to multiple target cels these cells attack undamaged target cells one at a time. The mean rate at which lethal hits are delivered per target cell is approximately the same for conjugates containing one or two target cells but slows substantially in conjugates containing three target cells. If our model is modified so that both previously hit and unhit target cells are susceptible to being lethally hit at the same rate, a very poor fit to Zagury et al's data is obtained. This leads us to conclude that previously hit cells are either not hit again or are hit at a substantially reduced rate.
The Bacteriophage-Antibacteriophage Reaction
Authors: Weiss Emil 
Published: December 2022

Summary and Conclusions
Bacteriophage mixed with antibacteriophage serum and incubated twenty-four hours at 37°C. or longer shows the following properties: Filtered through the colloidal sac, it does not influence bacterial growth.It does not penetrate an average agar layer in a Petri dish, but it penetrates it where mixed with normal serum or alone.It is precipitated with 13.5 per cent sodium sulphate, but remains in the filtrate, when mixed with normal serum or alone.Bacteriophage is not destroyed by its union with the antibacteriophage serum.When a mixture of bacteriophage and antibacteriophage serum is digested with trypsin the bacteriophage appears again active.
Macrophage maturation: differences in complement secretion by marrow, monocyte, and tissue macrophages detected with an improved hemolytic plaque assay.
Authors: Alpert S E , Auerbach H S , Cole F S , Colten H R 
Published: December 2022

Abstract
In order to examine one function of mononuclear phagocytes during maturation from bone marrow precursors to tissue macrophages, an improved hemolytic plaque assay for the detection of synthesis of the second (C2) and fourth (C4) components of C by single cells was developed. With this method, production of C2 and C4 was assessed in cell populations derived from bone marrow, blood, lung, peritoneum, and spleen. The proportion of cells producing C2 and C4 in each population varied. Approximately 10% of bone marrow cells produced C4, but not detectable C2 plaque-forming cells (PFC) were detected. Circulating monocytes yielded about 10% PFC each for C2 and C4. The proportion of C2-producing cells in tissue macrophages varied from approximately 2% in bronchoalveolar macrophages to about 45% in peritoneal and splenic macrophage populations, whereas C4 production by macrophages from lung, peritoneum, and spleen were all approximately 45%. These data suggest that differences in C biosynthesis characterize mononuclear phagocytes at different stages of maturation.
Two different rheumatoid factor-producing cell populations distinguished by the mouse erythrocyte receptor and responsiveness to polyclonal B cell activators.
Authors: Fong S , Vaughan J H , Carson D A 
Published: December 2022

Abstract
The subsets of human peripheral blood B lymphocytes from which Epstein Barr virus- (EBV) and pokeweed mitogen- (PWM) induced IgM anti-IgG autoantibody-producing B cells arise have been compared. EBV-induced IgM anti-IgG autoantibodies preferentially derive from a subset of B cells that forms rosettes with mouse erythrocytes. In contrast, PWM-induced IgM anti-IgG antibodies preferentially arise from a B cell subset lacking the mouse erythrocyte receptor.
Human T cell hybridomas specific for Epstein Barr virus-infected B lymphocytes.
Authors: Lakow E , Tsoukas C D , Vaughan J H , Altman A , Carson D A 
Published: December 2022

Abstract
A mutant of the Jurkat human T lymphoblastoid cell line deficient in hypoxanthine phosphoribosyltransferase, and resistant to ouabain, was fused with peripheral blood T lymphocytes primed in vitro with Epstein Barr virus- (EBV) transformed autologous B lymphocytes. After selection of somatic cell hybrids and cloning, hybridoma cell lines were obtained that reacted with autologous EBV-infected B lymphocytes, as detected by the release of interleukin 2 into the culture medium. The hybridomas did not react with i) EBV-uninfected autologous or allogeneic B lymphocytes, ii) three out of four allogeneic EBV-transformed cell lines, or iii) two established EBV-negative B cell lines. These functional hybridomas may ultimately prove useful in dissecting the means by which human T lymphocytes recognize and regulate EBV infection in vivo.
Induction of human IgE synthesis by a factor derived from T cells of patients with hyper-IgE states.
Authors: Saryan J A , Leung D Y , Geha R S 
Published: December 2022

Abstract
The requirements for the induction of IgE synthesis in normal B cells were studied. In contrast to peripheral blood lymphocytes (PBL) from allergic subjects, normal PBL failed to synthesize IgE spontaneously in vitro. Pokeweed mitogen (PWM) and Epstein Barr virus (EBV) failed to induce IgE synthesis in normal PBL and in tonsil lymphocytes. In the case of PWM, this failure was not overcome by prior removal of T8+ cells, which were shown previously to contain IgE-specific suppressor cells. In the case of EBV, the failure to induce IgE synthesis was not overcome by prior removal of sheep rosette-forming cells. Supernatants of T cells derived from three groups of patients with elevated serum IgE (hyper-IgE syndrome, atopic dermatitis, and acute graft-vs-host disease) induced significant IgE synthesis in cultures of normal B cells without causing an increase in IgE synthesis. In contrast, supernatants of normal T cells failed to induce IgE synthesis. Release of the IgE isotype-specific helper factor was inhibited by cycloheximide and tunicamycin, and its activity was destroyed by treatment with trypsin and neuraminidase. These results indicate that whereas classical polyclonal B cell activators (PWM, EBV) fail to induce IgE synthesis by normal B cells, IgE synthesis is readily induced by an IgE-specific helper factor released by T cells from patients with hyper-IgE states.
Naturally abundant basophils in the snapping turtle, Chelydra serpentina, possess cytophilic surface antibody with reaginic function.
Authors: Mead K F , Borysenko M , Findlay S R 
Published: December 2022

Abstract
Basophils constitute 50 to 63% of the blood leukocytes in Chelydra serpentina, the snapping turtle. Immunoglobulin (Ig) on the surface of the turtle basophil was detected by indirect immunofluorescence by using an IgG fraction from rabbit anti-turtle Ig serum (RATIg) and a fluoresceinated goat anti-rabbit antibody incubated at 4 degrees C. However, when the cells were incubated with RATIg at 22 degrees C, the basophil number, as determined by Wright's stain and neutral red counts, decreased dramatically. This morphologic evidence of degranulation was directly proportional to the antiserum concentration. Degranulation also correlated with cell histamine release (r = 0.73). In other experiments, turtle basophils were found to express antigen-specific surface Ig after immunization with sheep red blood cells (SRBC). Washed basophils from immunized turtles formed basophil-SRBC rosettes in vitro. Basophils from control turtles did not. Basophil-SRBC rosettes could also be induced by in vitro passive sensitization by preincubation of normal turtle basophils in the SRBC immune turtle sera. This study shows clearly that the turtle basophil has an immune capacity analogous to the mammalian basophil/mast cell. This study also contains the first direct evidence for the existence of reaginic antibody (or antibodies) in an ectothermic vertebrate. Finally, C. serpentina is proposed as a unique animal model for the study of basophil function.
Antigenic determinants of vesicular stomatitis virus: analysis with antigenic variants.
Authors: Lefrancois L , Lyles D S 
Published: December 2022

Abstract
Antigenic variants of vesicular stomatitis virus (VSV) serotypes New Jersey and Indiana (VSV-NJ, VSV-Ind) were selected by using a panel of monoclonal antibodies (MAb) specific for the major surface glycoprotein (G-protein). The reactivity of antigenic variants with the panel of MAb confirmed observations made by competitive binding assays that four distinct antigenic sites (A-D)NJ on the VSV-NJ G-protein and four partially overlapping sites (A, B1, B2, C)Ind on the VSV-Ind G-protein are involved in virus neutralization. Furthermore, subregions within the A epitopes of both serotypes were detected by variant analysis. The frequency of variation at most epitopes was 1 in 10(5) for VSV-NJ and 1 in 10(6) for VSV-Ind. The A3 and C determinants of VSV-Ind, however, defined by MAb that exhibited overlap in binding to other epitopes, appeared to be relatively invariant. Multiple mutations may be necessary to abolish antibody binding at these sites. Overlap of the C group of anti-VSV-Ind MAb with the A epitopes was assigned to the A2 subregion, because variants selected with A2 MAb show reduced binding of C MAb. Heterogeneous antisera from a primary immune response could detect differences in reactivity between variants at the A epitopes and wild-type VSV-NJ or VSV-Ind, suggesting the A epitope is immunodominant. Hyperimmune sera could detect a small difference between ANJ and BNJ variants compared to wild-type VSV-NJ, but could not distinguish between VSV-Ind variants and wild-type VSV-Ind.
Qualitative differences between dimeric and trimeric stimulation of human basophils.
Authors: MacGlashan D W , Schleimer R P , Lichtenstein L M 
Published: December 2022

Abstract
Previous studies from this laboratory demonstrated differences between antigenic and anti-IgE antibody stimulation of human basophils under the pharmacologic control of indomethacin. We show here that this difference may be due to the type of aggregation these stimuli induce on the cell surface. We found that the synthetically cross-linked trimer of IgE caused histamine release that was enhanced by indomethacin, whereas dimeric IgE induced-release was not. This result was not due to a difference in the kinetics of release by these two stimuli. These results suggest that the state of aggregation of Fc receptors differentially affects various cellular enzyme systems.
Modulation of granulomatous hypersensitivity. V. Participation of histamine receptor positive and negative lymphocytes in the granulomatous response of Schistosoma mansoni-infected mice.
Authors: Weinstock J V , Chensue S W , Boros D L 
Published: December 2022

Abstract
The possible role of histamine and histamine-receptored inflammatory cells in the granulomatous response of Schistosoma mansoni-infected mice was examined. Special staining revealed the presence of numerous mast cells, many partially degranulated within the liver granulomas. Treatment of infected mice with cimetidine (an H2 receptor antagonist) enhanced, and diphenyhydramine (an H1 receptor antagonist) decreased the granulomatous response. Fluorescein-labeled histamine-rabbit serum albumin conjugate (H-FRSA) and unlabeled conjugate (H-RSA)-coated culture plates were used to identify and isolate cells with histamine receptors. A large proportion of granuloma macrophages, lymphocytes, eosinophils, neutrophils, and splenic lymphocytes had histamine receptors. Elution of adherent cells from H-RSA-coated culture plates with H1 or H2 receptor antagonists suggested that receptors on granuloma cells were predominately H1 with some granuloma lymphocytes bearing H2-type receptors. Splenic lymphocytes from infected mice were functionally divided according to the presence or absence of histamine receptors on their cell surface. Receptor-negative lymphocytes appeared to mediate SEA-stimulated MIF production (TDH cells) and participated in the adoptive transfer of suppression of granulomas (TH cells). Whereas, TS cells appeared to have histamine receptors. Based on these data, it is inferred that lymphocytes that regulate lymphokine production (TS cells) within the granuloma may be triggered via their histamine receptors to exert suppressive activity.
Growth and characterization of T cell colonies from human thymus.
Authors: Lederman H M , Lee J W , Price G B , Gelfand E W 
Published: December 2022

Abstract
A semisolid microculture system was used to study T cell colonies grown from human thymocytes. Colony growth was absolutely dependent upon media conditioned by peripheral blood leukocytes (PBL) in the presence of phytohemagglutinin. Plating efficiency was further enhanced by the addition of a non-T, adherent, radiation-resistant (7500 rad) PBL subpopulation, but was not enhanced by culture supernatants of these cells. The T colony precursor cell in the thymus occurred with a frequency of 8.0 X 10(-3) and had a surface receptor for the OKT3 monoclonal antibody. Thymocyte colony cells were functionally distinct from PBL and the major thymocyte population. The colony cells proliferated in response to T cell mitogens, but only in the presence of exogenous growth factors. The cells stimulated normal PBL in mixed leukocyte culture (MLC), but did not respond to alloantigens in MLC or in assays of spontaneous cytotoxicity. This culture system should prove helpful in the study of human thymocyte differentiation.
Characterization of a "heteroclitic" cytotoxic lymphocyte clone: heterogeneity of receptors or signals?
Authors: Russell J H , Dobos C B 
Published: December 2022

Abstract
In this work we report the isolation of a cloned CTL that recognizes three genetically distinct specificities. Of interest is the fact that the hierarchy of the strength of these specificities is dependent on the functional assay used for their detection. This suggests that either the specificities are the result of interactions with independent receptors or the cell can modulate signals from cross-reactive antigens into different functional responses.
Activation of antigen-enriched b cells. I. Purification and response to thymus-independent antigens.
Authors: Snow E C , Vitetta E S , Uhr J W 
Published: December 2022

Abstract
The development of a procedure for the selection of a large number of functional antigen-binding B cells is described. Forty to 70% of the cells in the enriched population bind antigen, and the antigen-binding can be inhibited by pretreatment with either the free hapten (TNP-Lys) or anti-immunoglobulin. The enriched cells express both slgM and slgD and respond to mitogenic stimuli by proliferating and developing into antibody-forming cells. In contrast to normal spleen cells, however, the enriched cells also proliferate in response to submitogenic levels of TNP-Brucella abortus and TNP-LPS.
Nonresponsiveness to the male antigen H-Y in H-2 I-A-mutant B6.C-H-2bm12 is not caused by defective antigen presentation.
Authors: de Waal L P , de Hoop J , Stukart M J , Gleichmann H , Melvold R W , Melief C J 
Published: December 2022

Abstract
The B6.C-H-2bm12 (bm12), H-2 I-Ab mutant, originated in the C57BL/6 (B6, H-2b) strain, is a nonresponder to the male antigen H-Y in both T cell proliferation and cytotoxic T lymphocyte (CTL) responses. Defective H-Y presentation by bm12-adherent cells, as a cause of the CTL nonresponsiveness, can be excluded, because 1) CTL from primed responder/nonresponder F1 female mice (B6/bm12 F1) were activated by H-Y antigen on antigen-presenting cells (apc) from either parent; 2) T cells from primed nonresponder bm12 females did not generate CTL to H-Y presented by responder B6 apc, but conversely, CTL from B6 females could be activated by antigen on bm12 apc; and 3) adherent cell-depletion experiments indicated that male adherent cells are necessary for generation of optimal H-Y-specific CTL responses, male adherent bm12 cells being equally as efficient as male adherent B6 cells in presentation to F1 T cells. The need for T helper cell activation by H-Y-presenting adherent cells during secondary in vitro restimulation can be circumvented by interleukin 2 (IL 2), because IL 2 completely restored the H-Y-specific CTL response of B6/bm12 F1 cells in cultures depleted of adherent cells. However, addition of IL 2 during in vitro restimulation of bm12 cells did not result in an H-Y-specific CTL response, indicating that H-Y-specific, I-A-restricted T helper cells are probably needed in vivo during priming for the generation of sufficient numbers of Db-restricted CTL memory cells. The data are compatible with the concept that H-Y antigen is presented in the context of the I-A alpha, beta molecule on the surface of adherent cells to T helper cells and in the context of the Db molecule on the surface of nonadherent as well as adherent cells to CTL precursors. The most likely explanation for the difference in H-Y response between B6 and bm12 include positive selection of the responder phenotype by the I-Ab alpha, beta molecule of the B6 strain or generation of suppressor T cells in the bm12 strain.