bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detection and partial characterization of a human mast cell carboxypeptidase.
Authors: Goldstein S M , Kaempfer C E , Proud D , Schwartz L B , Irani A M , Wintroub B U 
Published: December 2022

Abstract
Using a high performance liquid chromatography assay that detects the cleavage of the C-terminal leucine from angiotensin I, we have identified a carboxypeptidase activity in mast cells from human lung and in dispersed mast cell preparations from human skin. The enzyme activity was detected in a preparation of dispersed human mast cells from lung of greater than 99% purity and was released with histamine after stimulation with goat anti-human IgE. In nine preparations of dispersed human mast cells from lung of 10 to 99% purity, net percentage of release of carboxypeptidase correlated with the release of histamine, localizing carboxypeptidase to mast cell secretory granules. The enzyme activity was also detected in preparations of dispersed human mast cells from skin and in extracts of whole skin. The inhibitor profile and m.w. of carboxypeptidase activity from preparations of dispersed mast cells from skin was similar to that from dispersed mast cells from lung. Mast cell carboxypeptidase had a m.w. on gel filtration of 30,000 to 35,000. The enzyme in crude lysates of dispersed mast cell preparations had optimal activity between pH 8.5 and 9.5 and was inhibited by potato inhibitor, which distinguished it from carboxypeptidase in cultured human foreskin keratinocytes and adult fibroblasts, and from other proteolytic mast cell enzymes. The enzyme activity was also inhibited by EDTA, o-phenanthroline, and, to a small extent, by 8-OH quinoline, but not by Captopril, soybean trypsin inhibitor, or pepstatin. These findings demonstrate that human mast cell secretory granules contain carboxypeptidase in addition to tryptase and chymase. It appears that mast cells from skin may have a higher content of carboxypeptidase than do mast cells from lung.
Thymus-dependent in vivo suppression of IgE synthesis in a murine IgE-secreting hybridoma.
Authors: Mathur A , Kamat D M , Van Ness B G , Lynch R G 
Published: December 2022

Abstract
In previous studies we demonstrated that BALB/c mice bearing ascitic tumors of the IgE-secreting hybridoma B53 (epsilon, kappa, anti-dinitrophenyl) developed large numbers of Lyt-1-2+ Fc epsilon R(+) T lymphocytes (T cells with membrane Fc receptors) in response to the elevated serum IgE concentration. The development of Fc epsilon R(+) T lymphocytes was followed by a progressive decrease in the levels of serum IgE in spite of continued proliferation of the hybridoma cells. This sequence of events suggested that the IgE-secreting hybridoma triggered a suppressive immunoregulatory circuit of the host that inhibited IgE expression by the hybridoma cells. The present studies were undertaken to investigate the basis for the subsequent decline in serum IgE levels in mice with B53 tumors and to identify host factors that might be involved in this process. We observed that ascitic B53 cells recovered at increasing time points from BALB/c mice exhibited a selective decline in steady state levels and rates of synthesis of epsilon-heavy chain protein and mRNA. The expression of kappa-light chain protein and mRNA appeared relatively unchanged. The decrease in epsilon-heavy chain gene expression did not occur when B53 tumors were passaged in nu+/nu+ mice or in BALB/c mice depleted of Lyt-2+ cells (suppressor/cytotoxic cell lineage), but did occur in nu+/nu+ mice reconstituted with neonatal BALB/c thymus and in BALB/c mice depleted of L3T4+ cells (helper/inducer cell lineage). That Fc epsilon R(+) T lymphocytes were directly involved in the inhibition of IgE expression was supported by the earlier and more pronounced inhibition of B53 IgE in mice infused with Fc epsilon R(+) T lymphocytes. We conclude from these findings that: 1) the decline in serum IgE levels that occurs toward the end of each generation of in vivo passage of the B53 hybridoma is due to decreased production of IgE by the hybridoma cells, 2) the decreased production of IgE is due to a selective loss of epsilon mRNA expression, 3) the decrease production of IgE by B53 cells is dependent on the presence of Lyt-2+ cells, and 4) Fc epsilon R(+) T lymphocytes participate in the mechanism by which IgE production is suppressed.
Formyl peptide leukocyte chemoattractant uptake and release by cultured human umbilical vein endothelial cells.
Authors: Rotrosen D , Malech H L , Gallin J I 
Published: December 2022

Abstract
Recent observations support an active role for the vascular endothelial cell in the induction and evolution of the inflammatory response. Since prior studies suggested that cultured bovine endothelial cells express high affinity binding sites for the neutrophil chemotactic oligopeptide formyl methionyl-leucyl-phenylalanine (f-Met-Leu-Phe), we sought to further characterize the interaction between formyl peptide chemoattractants and human vascular endothelial cells. Cultured human umbilical vein endothelial cells and peripheral blood neutrophils specifically bound f-Met-Leu-[3H]Phe, whereas specific binding to cultured fibroblasts, smooth muscle, and epithelial cells was negligible. Endothelial cells expressed 3.6 +/- 0.7 X 10(5) binding sites/cell with a Kd of 210 +/- 31 nM. Although the hexapeptide formyl norleucyl-leucyl-phenylalanyl-norleucyl-tyrosyl-lysine (f-Nle-Leu-Phe-Nle-Tyr-Lys) and the tetrapeptide f-Met-Leu-Phe-Lys completed with f-Met-Leu-[3H]Phe for binding to endothelial cells, specific binding of 125I-f-Nl-Leu-Phe-Tyr-Lys or f-Met-Leu-Phe-Lys-fluorescein to endothelial cells was not observed, suggesting that steric constraints on formyl peptide binding differ between endothelial cells and leukocytes. At 37 degrees C, cell-associated f-Met-Leu-[3H]Phe greatly exceeded that bound at 0 degrees C and was incorporated predominantly into a nondisplaceable compartment. Release of f-Met-Leu-[3H]Phe or radioactive breakdown products from this compartment was time- and temperature-dependent with a t1/2 of approximately equal to 20 min at 37 degrees C. Resolution of the radioactive products released from f-Met-Leu-[3H]Phe-loaded endothelial cells by thin layer chromatography indicated that greater than or equal to 57% of the released material co-migrated with intact f-Met-Leu-[3H]Phe. Degradative release was blocked by agents that interfere with lysosomal acidification. The radioactive material released from f-Met-Leu-[3H]Phe-loaded endothelial cells bound specifically to neutrophils. This binding was inhibited 50.2 +/- 6.4% by a greater than or equal to 10(3)-fold excess of nonradioactive f-Met-Leu-Phe whereas binding of authentic f-Met-Leu-[3H]Phe was inhibited 89.4 +/- 3.0%. Supernatant obtained from f-Met-Leu-[3H]Phe-loaded endothelial cells elicited a rise in neutrophil cytosolic free calcium ([Ca2+]i) measured by quin2 fluorescence. The change in neutrophil [Ca2+]i depended on ligand binding to the neutrophil formyl peptide receptor since endothelial supernatants were devoid of activity in the presence of the f-Met-Leu-Phe antagonist, tert-butoxycarbonyl-Phe-Leu-Phe-Leu-Phe.(ABSTRACT TRUNCATED AT 400 WORDS)
Cationization of protein antigens. IV. Increased antigen uptake by antigen-presenting cells.
Authors: Apple R J , Domen P L , Muckerheide A , Michael J G 
Published: December 2022

Abstract
Cationization of BSA generates a molecule that mounts antibody responses of increased magnitude and duration and induces T cell proliferation at concentrations 500 times less than native BSA (nBSA). To explain the alteration in immunogenic properties of this Ag, the uptake of nBSA and cationized BSA (cBSA) by splenic APC has been investigated. T cell proliferation assays were conducted with nBSA and cBSA preparations with varying degrees of substitution. An inverse correlation between the degree of cationization and the amounts of Ag needed for optimal T cell reactivity was observed. To determine whether affinity for APC resulted in an increased uptake of cBSA, splenic APC were incubated with nBSA or cBSA for varying amounts of time. Comparisons were made at each time point between untreated Ag-pulsed APC (Ag uptake) and paraformaldehyde-fixed Ag-pulsed APC (processed Ag). Proliferation of T cells primed with nBSA or cBSA increased in proportion to the amount of time of APC exposure to high concentrations of nBSA, first appearing after a 2-h pulse and peaking at 8 h. Conversely, untreated APC needed only a 30-min cBSA exposure to induce either nBSA- or cBSA-primed T cell proliferation, indicating a rapid uptake of cBSA. Comparisons with proliferation induced by paraformaldehyde-fixed cBSA APC indicate that nBSA T cells recognize a lag phase-processed form of cBSA, whereas a majority of cBSA T cells recognize either a rapidly processed form of cBSA, or a membrane-processed cBSA molecule without a classical lag phase processing event. When monensin was used as an inhibitor of fluid phase pinocytosis in splenic APC, the presentation of nBSA was inhibited by 85%, but the presentation of cBSA was inhibited by only 20%. These results imply that nBSA enters the cell by fluid phase pinocytosis, whereas cBSA enters by a nonspecific adsorptive mechanism. The different modes of cellular entry for the two molecules, nBSA and cBSA, resulting in a rapid uptake of cBSA, may have important ramifications on T cell activation and immunoregulation.
In vitro analysis of the interactions of recombinant IL-2 with regenerating lymphoid and myeloid cells after allogeneic marrow transplantation.
Authors: Heslop H E , Price G M , Prentice H G , Cordingley F T , Webster A D , Hoffbrand A V , Brenner M K 
Published: December 2022

Abstract
Although administration of rIL-2 post-T depleted allogeneic bone marrow transplantation (TD-BMT) offers the prospect of augmenting immune reconstitution and thereby reducing the risks of infection and relapse, it has been unclear what direct or indirect effects this agent would have on the regenerating myeloid system. We find that addition of 200 IU or rIL-2 to patient lymphocytes obtained within 6 wk of TD-BMT results in a substantial (2 to 3 log) increase in INF-gamma secretion and the production of TNF. Cytokines present in supernatants obtained from IL-2-stimulated patient lymphocytes have two contrasting effects on myeloid cells from normal donors and from marrow recipients. They prime granulocytes for enhanced oxidative metabolism as measured by ability to generate chemiluminescence in response to FMLP, whereas IL-2 added directly to neutrophils has no effect. However, these IL-2-induced cytokines also act to inhibit myeloid progenitor growth and reduce granulocyte macrophage (GM) colony formation by a mean of 53%. Preincubation of supernatants with anti-IFN-gamma antibody partially abrogates both enhancement of granulocyte chemiluminescence and suppression of marrow CFU-GM. Addition of IL-2 directly to recipient marrow also produces inhibition, leading to a 25% reduction of GM-colony growth. This effect is not due to direct interaction between myeloid progenitor cells and IL-2, because it is completely abrogated by removal of CD8 and Leu-7+ lymphocytes from the marrow. Although the suppressive effects on marrow growth in vitro are of particular concern after BMT, the potential of IL-2 to promote granulocyte function, immune reconstitution, and anti-leukemic activity after TD-BMT justify further consideration of IL-2 therapy in this setting.
Molecular linkage of the Ly-3 and Ly-2 genes. Requirement of Ly-2 for Ly-3 surface expression.
Authors: Gorman S D , Sun Y H , Zamoyska R , Parnes J R 
Published: December 2022

Abstract
We have isolated the Ly-3 gene by chromosomal walking from the previously cloned Ly-2 gene. These genes are shown to be 36 kb apart and in the same transcriptional orientation. Transfection of the Ly-3 gene into mouse L cells results in cell surface expression of Ly-3 protein only in the presence of Ly-2 (or its human homolog, CD8), although Ly-2 surface expression is not similarly dependent on Ly-3. cDNA clones encoding Ly-3 have been isolated and sequenced and show little sequence similarity to Ly-2, whereas both Ly-2 and Ly-3 are homologous to Ig variable regions. One cDNA clone encodes a form of Ly-3 lacking a transmembrane region. Although two alleles of Ly-3 have been previously defined serologically, Northern blot analyses of Ly-3 mRNA from a series of inbred mouse strains show unusual polymorphisms in the lengths of Ly-3 mRNA species defining at least three allelic variants of this gene.
Prerequisite for the induction of lymphokine-activated killer cells from T lymphocytes.
Authors: Sawada H , Abo T , Sugawara S , Kumagai K 
Published: December 2022

Abstract
Human blood mononuclear cells were separated into Leu-11+7-NK, Leu-11-7+, and Leu-11-7-T cells by means of a combination of the Percoll gradient method and C-mediated cytolysis using mAb. When purified Leu-11+7-NK, Leu-11-7+, and Leu-11-7-T cells were cultured with rIL 2 (500 U/ml) for 6 days in a medium supplemented with 10% FCS, Leu-11+7-NK cells responded at the maximum level and Leu-11-7+ cells responded moderately as shown by both cell-proliferation response and cytotoxic activity generated. On the other hand, Leu-11-7-T cells did not respond at all to rIL-2. However, when Leu-11-7-T cells were cultured with rIL-2 in a medium supplemented with 10% autologous serum, they showed considerable responsiveness to rIL-2. In addition, much greater response to Leu-11-7-T cells were produced by the addition of monocytes. Monocyte cytokines, neither IL 1, IFN-gamma, TNF, nor their combination were able to substitute for monocytes in the induction culture. In contrast, the response level of Leu-11+7- NK cells remained unchanged irrespective of supplementation with autologous serum to medium or the addition of monocytes to the culture. These results indicated that culture conditions in the experiments significantly affected the results as to determination of lymphokine-activated killer cell precursors, especially the result pertaining to the conversion of T lymphocytes to lymphokine-activated killer cells. Under appropriate conditions, not only NK cells but also T cells are important precursors of lymphokine-activated killer cells.
Identification of a murine pan-T cell antigen which is also expressed during the terminal phases of B cell differentiation.
Authors: Gulley M L , Ogata L C , Thorson J A , Dailey M O , Kemp J D 
Published: December 2022

Abstract
A new rat anti-mouse mAb, designated S7, is described. The antibody, an IgG2a, reacts with all Thy-1.2-positive cells and all granulocytic cells in the marrow. Resting B cells are non-reactive but, during the terminal phases of LPS-induced B cell differentiation, the S7 determinant appears and reaches high levels of expression. S7 will probably be useful in studies aimed at subdividing the later stages of the B cell maturation process.
Effects of in vivo administration of anti-T3 monoclonal antibody on T cell function in mice. I. Immunosuppression of transplantation responses.
Authors: Hirsch R , Eckhaus M , Auchincloss H , Sachs D H , Bluestone J A 
Published: December 2022

Abstract
Anti-T3 mAb are being increasingly used clinically in the treatment of organ graft rejection. However, there has not previously been a murine model in which the effects of these mAb on the immune system could be studied in vivo. We have established such a model using the anti-murine-T3 mAb, 145-2C11. Administration of 145-2C11 led to rapid depletion of T cells from peripheral blood and suppression of skin graft rejection. However, depletion of T cells from spleen and lymph node was both delayed and incomplete. Full recovery of T cell number was dependent on the presence of a thymus, but treatment of thymectomized animals revealed that depletion was not the mechanism by which the mAb induced immunosuppression. Rather, alterations in TCR expression may play a more important role. TCR had modulated from T cells in spleen and lymph node early after treatment, and TCR expression remained subnormal for at least 51 days posttreatment. However, subnormal TCR expression alone could not fully explain the observed T cell dysfunction, inasmuch as a period of time existed after TCR re-expression during which T cells appeared to be anergic to CTL and MLR reactivity. These findings implicate T cell dysfunction as an important element in the induction of immunosuppression after anti-T3 administration.
Mechanism involved in the mobilization of neutrophil calcium by 5-hydroxyeicosatetraenoate.
Authors: O'Flaherty J T , Jacobson D , Redman J 
Published: December 2022

Abstract
5-Hydroxyeicosatetraenoate (5-HETE), like leukotriene B4 and platelet-activating factor, stimulated human polymorphonuclear neutrophils to mobilize intracellular calcium. The three compounds acted through mechanisms that were inhibited by pertussis toxin, cholera toxin, and PMA. Each agonist, furthermore, desensitized (or down-regulated) the neutrophil's calcium mobilization response to a second challenge with the same agonist. However, 5-HETE and leukotriene B4 had little or no activity in cross-desensitizing neutrophil responses to each other or to platelet-activating factor. Furthermore, 5-HETE interfered minimally or not at all with the binding of radiolabeled leukotriene B4 and platelet-activating factor to their respective receptors on neutrophils. Thus, 5-HETE mobilizes neutrophil calcium by a mechanism different from those used by leukotriene B4 and platelet-activating factor. This mechanism appears to involve specific 5-HETE receptors that couple to pertussis toxin-inhibitable, GTP-binding proteins.
Inhibition of macrophage tumoricidal activity by glucocorticoids.
Authors: Hogan M M , Vogel S N 
Published: December 2022

Abstract
In this study, the effect of corticosteroids on the activation of macrophages to a fully tumoricidal state was examined. Thioglycolate-elicited peritoneal exudate macrophages from C3H/HeJ mice were rendered cytolytic for P815 mastocytoma cells in a two-signal tumoricidal assay that used recombinant interferon-gamma (rIFN-gamma; 1 to 10 U/ml) as a "priming" signal and butanol-extracted lipopolysaccharide (But-LPS; 0.1 to 5 micrograms/ml) as a "trigger" signal. Treatment of macrophages with either rIFN-gamma alone or But-LPS alone failed to result in significant cytolytic ability. Tumoricidal activity was markedly inhibited in a dose-dependent fashion when glucocorticoids were added simultaneously to the cultures with rIFN-gamma and But-LPS at concentrations ranging from 1 X 10(-10) to 1 X 10(-5) M. Nonglucocorticoid sex hormones failed to inhibit tumoricidal activity in this system under identical culture conditions. Inhibition was most effective if the glucocorticoids were added simultaneously with the priming and triggering signals (rIFN-gamma and But-LPS); however, if the glucocorticoids were added 24 hr after the signals were provided to the cultures, suboptimal inhibition was observed. Experiments that dissociated the priming phase of activation from the triggering phase showed that glucocorticoids inhibited both the rIFN-gamma-induced priming stage as well as the But-LPS-induced triggering stage of activation. These observations provide evidence that glucocorticoids, but not other steroid hormones, inhibit the activation of macrophages to a fully tumoricidal state by interfering with either the priming or triggering signals in this two-signal model of macrophage activation.
IgA:IgM and IgA:IgA hybrid hybridomas secrete heteropolymeric immunoglobulins that are polyvalent and bispecific.
Authors: Urnovitz H B , Chang Y , Scott M , Fleischman J , Lynch R G 
Published: December 2022

Abstract
Polyvalent bispecific antibodies were secreted by hybrid hybridoma cells when both parental clones expressed a naturally polymerizing immunoglobulin. Hybrid hybridomas made from IgA lambda 2 anti-trinitrophenyl (TNP) and IgA kappa anti-phosphocholine (PC) parental cells secreted polymeric IgA antibodies that bound both TNP and PC. Some of the TNP binding was dissociated from the PC binding under conditions of mild reduction and alkylation suggesting that the bispecific polymeric IgA contained disulfide-linked parental monomers as well as bispecific hybrid monomers. Hybrid hybridomas constructed from IgA lambda 2 anti-TNP and IgM kappa anti-ox erythrocyte parental cells secreted bispecific, polymeric immunoglobulin that contained mu-, alpha-, kappa-, and lambda 2-chains. The mu and kappa-chains dissociated from the alpha- and lambda 2-chains under conditions of mild reduction and alkylation, indicating that both parental monomers had been incorporated into the same polymeric immunoglobulin to form a heteropolymeric antibody molecule. Heterologous pairing of alpha and mu heavy chains in monomers was not detected. Hybrid hybridomas constructed from IgA lambda 2 and IgG3 lambda 2 or IgA lambda 2 and IgG1 kappa parents co-secreted both parental immunoglobulins, but the antibodies secreted by these clones did not form heteropolymers or exhibit heterologous heavy chain pairing. These findings establish that polyvalent, bispecific, polymeric immunoglobulin molecules can be produced by hybrid hybridomas when both parents express a naturally polymerizing class of heavy chain but not when only one parent does. Hybrid hybridomas that produce heteropolymeric immunoglobulins are sources of high avidity bispecific antibodies that may find a number of basic and practical applications. The hybridoma cells that produce these antibodies may provide useful tools for investigating the in situ determinants of immunoglobulin chain association and the regulation of antibody assembly and secretion.
Motility of murine lymphocytes during transit through cell cycle. Analysis by a new in vitro assay.
Authors: Ratner S , Jasti R K , Heppner G H 
Published: December 2022

Abstract
The relationship between the basal (spontaneous) motility of murine lymphocytes and their position in the cell cycle was examined in a new collagen gel motility assay system. Concanavalin A-stimulated or control lymphocytes were allowed to locomote into slabs of type I collagen gel. The assay configuration permitted extraction of both total populations and locomotory subpopulations as viable, single-cell suspensions suitable for phenotypic and cell analysis. Concanavalin A stimulation resulted in a significant increase in the mean distance traveled by the leading cell front in 4 hr, from 23 microns (controls) to 67 microns. The estimated percentage of motile cells increased from 0.9 to 2.8%. Similar increases were observed after 18 hr of locomotion. The SIg+, Thy-1+, L3T4+, and Ly-2+ subsets exhibited equivalent increases in motility. Total populations and locomotory subpopulations were allowed to incorporate 5-bromo-2'-deoxyuridine, and their cell cycle profiles were compared by dual parameter anti-5-bromo-2'-deoxyuridine, propidium iodide fluorescence analysis. Total population and locomotory subpopulations did not differ significantly with respect to the ratio G0/G1:S, indicating that lymphocytes in these two phases exhibited approximately equal motility. Cells in late S and G2 + M were significantly less motile; locomotory subpopulations contained 60 to 75% fewer G2 + M cells than the total populations from which they were derived. Taken together, the results indicate that the concanavalin A-induced increase in motility commences before S phase and that motility diminishes shortly before or during G2 + M.