bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human monocyte inflammatory mediator gene expression is selectively regulated by adherence substrates.
Authors: Eierman D F , Johnson C E , Haskill J S 
Published: December 2022

Abstract
During the process of extravasation, monocytes transiently adhere to capillary endothelium and subsequently with a variety of extracellular matrix components. These early interactions are likely to serve as modifiers of transcriptional activity and serve to prime monocytes for rapid synthesis of mediators. We have previously reported that adherence to plastic rapidly induced or down-regulated steady-state mRNA levels of a number of monocyte inflammatory mediator genes. We now report that adherence to surfaces pretreated with fibronectin resulted in TNF-alpha and CSF-1 mRNA levels approximating adherence to plastic, whereas adherence to fibronectin, fibronectin/anti-fibronectin complexes, or collagen resulted in markedly decreased levels of CSF-1 induction and lysozyme down-regulation. In contrast, monocyte adherence to collagen induced the highest sustained levels of TNF-alpha expression. PMA, but not the chemotactic factor FMLP, stimulated non-adherent monocytes to express c-fos and TNF-alpha and down-regulate lysozyme mRNA. Although all donors responded to adherence, several failed to produce CSF-1 mRNA after PMA stimulation in the non-adherent state. These data demonstrate that monocyte mediator expression may be more dependent on the selectivity of signals induced by adherence to different substrates than the initial chemotactic response.
Synthesis and regulation of C1 inhibitor in human skin fibroblasts.
Authors: Katz Y , Strunk R C 
Published: December 2022

Abstract
Proteins of the C1 complex, C1q, C1r, and C1s, of the classical pathway of complement activation are known to be synthesized in human skin fibroblasts. Using metabolic labeling with [35S]methionine, immunoprecipitation, and SDS-PAGE, we demonstrate that human skin fibroblasts synthesize and secrete C1 inhibitor with an apparent molecular mass of 78 kDa in the cell lysate and 102 kDa in the extracellular medium. This C1 inhibitor had the capacity to bind activated C1s. Fibroblasts synthesized 30- to 50-fold more C1 inhibitor than was synthesized in monocytes. As previously reported, fibroblasts also synthesized C1r and C1s. IFN-gamma, IFN-beta 1, and TNF had significant, but distinct, effects on synthesis of C1 inhibitor, C1r, and C1s. Incubation of the cells with IFN-gamma, 1000 U/ml, for 24 h induced increases in the synthesis of C1 inhibitor, C1r, and C1s by 4.2-, 1.9- and 1.6-fold, respectively. IFN-beta 1 had effects similar to IFN-gamma, although smaller in magnitude. TNF, 12.5 ng/ml, induced increases in the synthesis of C1 inhibitor, C1r, and C1s by 1.5-, 1.4- and 2.6-fold. IL-1, IFN-beta 2 (IL-6), and LPS did not affect synthesis of C1 inhibitor, C1r, or C1s. Fibroblasts are present in large amounts in most tissues. Synthesis of C1 inhibitor, C1r, and C1s by these cells could provide a source of these important proteins in body tissues. In addition, fibroblasts should be a good model for the in vitro study of genetic diseases involving the synthesis of these proteins.
Monoclonal antibodies against the CD44 [In(Lu)-related p80], and Pgp-1 antigens in man recognize the Hermes class of lymphocyte homing receptors.
Authors: Picker L J , De los Toyos J , Telen M J , Haynes B F , Butcher E C 
Published: December 2022

Abstract
An 85- to 95 kDa class of lymphocyte surface molecules, defined in man by antibodies of the Hermes series, is involved in lymphocyte binding to high endothelial venules and is likely of central importance in the process of lymphocyte homing. In this report, we have examined the relationship between these Hermes-defined "homing-receptors" and two other 80 to 95 kDa lymphocyte surface molecules that have been extensively studied--CD44 [In(Lu)-related p80] defined by mAb A1G3 and A3D8, and Pgp-1 defined by antibody IM7. Our findings indicate that, in man, similar or identical glycoprotein(s) are recognized by these independently and diversely obtained antibodies. All antibodies showed identical immunohistologic patterns of reactivity on a variety of lymphoid and nonlymphoid human tissues, and demonstrated similar bands on Western blots of both crude tonsil lymphocyte lysates and highly purified Hermes-1 Ag preparations. Similarly, purified CD44/p80 Ag from RBC and human serum bound Hermes-1. Preclearing of tonsil lysates with the Hermes-1 antibody removed antigenic activity for all antibodies. Cross-blocking experiments demonstrated that A3D8, IM7 (anti-Pgp-1), and Hermes-2 antibodies recognize overlapping epitopes. Finally, expression of the epitopes defined by the Hermes-1, Hermes-3, H2-7, and H3-61 antibodies on RBC was shown to be regulated by the In(Lu) gene. These findings unify several different lines of investigation, and suggest the possibility that the CD44/Pgp-1/Hermes class of molecules may serve as cell-cell or cell-substrate adhesion/recognition elements for both hematolymphoid and non-hematolymphoid cell types.
Tumor targets stimulate IL-2 activated killer cells to produce interferon-gamma and tumor necrosis factor.
Authors: Chong A S , Scuderi P , Grimes W J , Hersh E M 
Published: December 2022

Abstract
Lymphokine-activated killer (LAK) cells are cytotoxic for a variety of autologous and allogeneic tumor cells as well as modified autologous cells. It is assumed that LAK cells lyse their targets solely by direct cell to cell contact, possibly involving the degranulation and exocytosis of pore-forming elements, similar to that observed with cytotoxic T lymphocytes and NK cells. Reported here are studies demonstrating that LAK cells release factor(s) that are cytotoxic for a human breast carcinoma cell line, MCF-7, when stimulated with tumor cells. The factor(s) are slow acting and maximum cytotoxicity is observed only in a 72-h cytotoxic assay. The ability of LAK cells to secrete cytotoxic factor(s) is dependent on both the ratio of LAK cells to stimulating tumor cells as well as the length of their coincubation. A number of similarly slow acting cytokines that are cytostatic and/or cytotoxic for tumor cells have been described. We tested the ability of specific polyclonal antibodies directed against TNF, IFN-alpha, IFN-beta, and IFN-gamma to neutralize the cytotoxic supernatant activity. Only antibodies specific for IFN-gamma and TNF were neutralizing. We measured the amounts of IFN-gamma and TNF in the cytotoxic supernatants and determined that increased amounts of IFN-gamma and TNF were released after LAK cell-tumor cell interactions compared to supernatants of LAK cells alone or tumor cell alone. Comparable concentrations of human rIFN-gamma and rTNF resulted in similar levels (50 to 90%) of MCF-7 cell cytotoxicity as those observed with the stimulated LAK cell supernatants. We thus concluded that the majority of the cytotoxic activity released by LAK cells when stimulated with tumor cells was attributed to the synergistic activities of IFN-gamma and TNF. The significance of these observations in relation to the possible mechanisms by which LAK cells mediate cytolysis is discussed.
Identification of proteases that process distinct epitopes on the same protein.
Authors: Takahashi H , Cease K B , Berzofsky J A 
Published: December 2022

Abstract
Proteolytic degradation of protein antigens is thought to be a major step in the processing of Ag for presentation to T cells, but the range of proteases involved is unknown. Here we used a large panel of protease inhibitors to determine the role of each of the four classes of proteases in antigen processing. Moreover, we asked whether different proteases were necessary for presentation of different known epitopes, defined by three Th cell clones. For all three epitopes of myoglobin, intracellular thiol proteases such as cathepsins B or L were the only proteases necessary. Furthermore, myoglobin pre-digested with cathepsin B could be presented to all three clones without further processing. Thus, a single protease may be both necessary and sufficient for Ag processing to present the majority of epitopes, at least for myoglobin. This finding provides an explanation of earlier data on the fragments produced from processed myoglobin, and so may contribute to a much needed solution to the long standing problem of predicting where a protein will be cleaved during processing.
Soluble CD8 during T cell activation.
Authors: Tomkinson B E , Brown M C , Ip S H , Carrabis S , Sullivan J L 
Published: December 2022

Abstract
The CD8 Ag has long been used as a surface marker for the identification of cytotoxic and suppressor cells. Recently CD8-positive cells have been shown to release a soluble form of the CD8 Ag. We have devised a sandwich monoclonal enzyme immunoassay for the quantitation of this released CD8. Soluble CD8 was released in response to lymphocyte activation. In vitro, PHA or anti-CD3 mAb-mediated T cell activation led to release of CD8 into the culture supernatant. In vivo, serum from patients with EBV-induced infectious mononucleosis (IM), a disease associated with intense CD8+ T cell activation, demonstrated elevations in soluble CD8 (7939 U/ml, day 0) compared to serum from normal controls (289 U/ml). Levels of soluble CD8 correlated (r = 0.82, p less than 0.001) with the increased percentage of CD8+/HLA-DR+ (activated CD8+ T cells) observed in acute IM. Sequential analysis of serum during the course of IM shows that soluble CD8 levels parallel the decline in CD8+/HLA-DR+ cells that occurs with the resolution of the disease. These data suggest that released CD8 may be of value in monitoring the involvement of CD8+ T cells in response to a pathologic event. The functional role of the released CD8 molecule will require further investigation.
Binding characteristics of dimeric IgG subclass complexes to human neutrophils.
Authors: Huizinga T W , Kerst M , Nuyens J H , Vlug A , von dem Borne A E , Roos D , Tetteroo P A 
Published: December 2022

Abstract
Immune complexes were prepared by incubation of human IgG paraproteins with F(ab')2 fragments of the mAb K35 against the kappa-L chain of human IgG. The composition of these complexes was analyzed by centrifugation over sucrose gradients, by gel filtration, by RIA with either IgG Sepharose or K35 Sepharose and by double-labeling studies. The results indicated that the complexes consist of saturated tetramers composed of two IgG molecules cross-linked by two F(ab')2 fragments of the mAb. These complexes were used to study the binding of the different IgG subclasses to human neutrophils at 4 degrees C. Human neutrophils bound IgG3 complexes approximately three times faster than IgG1 complexes. Binding of IgG2 or IgG4 dimers to the neutrophils was undetectable. The same number of IgG1 complexes and IgG3 complexes bound to the neutrophils, but considerable inter-donor variation was found (mean number of Fc gamma R per neutrophil: 190,000, range 120,000 to 400,000). The Ka for the binding of IgG1 complexes to neutrophils (median 11 x 10(7) M-1) was lower than the Ka for the binding of IgG3 complexes (median 47 x 10(7) M-1). Competition studies between labeled IgG1 complexes or IgG3 complexes and unlabeled complexes showed that the Fc gamma R of human neutrophils do not display an IgG subclass specificity. Incubation of neutrophils with a mAb against the FcRIII completely blocked the binding of IgG1 complexes and IgG3 complexes. Incubation with a mAb against the FcRII reduced the affinity of the complexes for the neutrophils but had no effect on the maximum number of complexes bound. This indicates that one complex may bind simultaneously to one FcRIII and to one FcRII.
The 40-kDa Fc gamma receptor (FcRII) on human neutrophils is essential for the IgG-induced respiratory burst and IgG-induced phagocytosis.
Authors: Huizinga T W , van Kemenade F , Koenderman L , Dolman K M , von dem Borne A E , Tetteroo P A , Roos D 
Published: December 2022

Abstract
Neutrophils express two types of receptor for the Fc region of IgG, FcRII and FcRIII. Per neutrophil, 10,000 to 20,000 molecules of FcRII (40 kDa) and 100,000 to 200,000 molecules of FcRIII (50 to 80 kDa) are expressed. Via these receptors, neutrophils bind IgG complexes that contain more than one IgG molecule. This binding activates functional processes, such as the respiratory burst and phagocytosis. We studied the contribution of FcRII and FcRIII in the activation of these processes, using well-defined complexes (both large and small) in combination with mAb against FcRII and FcRIII. Small (dimeric) IgG complexes appeared to bind via FcRIII. However, binding to FcRIII alone, when FcRII is blocked by an anti-FcRII mAb, did not induce a respiratory burst. Induction of the respiratory burst by a large immune complex, such as Staphylococcus aureus Wood opsonized with IgG antibodies, was mediated by binding to FcRII, because it was blocked by an anti-FcRII mAb but not by an anti-FcRIII mAb. This indicates that these IgG-opsonized bacteria can cross-link FcRII and activate the cells without the need to adhere to the FcRIII. The respiratory burst induced by IgG-latex was not inhibited by an anti-FcRII mAb, because the avidity for FcRII of IgG-latex, a particle of the same size as a Staphylococcus but with a two to three times higher IgG content, is increased by its simultaneous binding to FcRIII. This enhanced avidity results in removal of anti-FcRII mAb from the FcRII by IgG-latex. This increased avidity of large complexes for FcRII, created by concurrent binding to FcRIII, is not necessary for activation of human neutrophils, because neutrophils from patients with paroxysmal nocturnal hemoglobinuria, with about 10% of the normal FcRIII expression, showed a normal metabolic response upon addition of IgG-latex. Phagocytosis of IgG-opsonized 14C-labeled S. aureus Wood was inhibited equally well by anti-FcRII mAb and by anti-FcRII in combination with anti-FcRIII mAb. Thus, FcRII is not only essential for the IgG-induced activation of the NADPH oxidase system, but also for the IgG-induced phagocytosis.
Activation of human monocytes occurs on cross-linking monocytic antigens to an Fc receptor.
Authors: MacIntyre E A , Roberts P J , Jones M , Van der Schoot C E , Favalaro E J , Tidman N , Linch D C 
Published: December 2022

Abstract
Murine mAb to CD13, CD14, and class II MHC, are able to mobilize calcium in normal human monocytes and enhance superoxide production in primed cells. Antibodies to CD35 (CR1) also cause a minor calcium response in some individuals. Antibodies to CD11a, CD11b, CD11c, CD15, CD17, CD18, and CD45 do not activate monocytes. The ability of mAb to cause monocyte activation is not only dependent on the Ag with which they react but also on the isotype of the antibodies and the individual from whom the monocytes were obtained. It is shown that this is because the mAb that activate monocytes do so by formation of Ag-antibody-FcR complexes. F(ab')2 fragments of mAb to CD13 and CD14 do not therefore activate monocytes even when cross-linked with F(ab')2 anti-mouse Ig but do so when cross-linked with intact anti-mouse Ig. These data indicate that activation via the FcR requires perturbation of this receptor but does not necessarily require cross-linking of one FcR to another. Antibody-coated particles or cells able to bind to cell surface receptors on monocytes other than the FcR would thus augment FcR-mediated activation.
Binding of human C-reactive protein to mouse macrophages is mediated by distinct receptors.
Authors: Zahedi K , Tebo J M , Siripont J , Klimo G F , Mortensen R F 
Published: December 2022

Abstract
Human C-reactive protein (CRP) is known to activate mouse macrophages (M phi) to a tumoricidal state and to serve as an opsonin for M phi. Therefore, cell surface receptors for CRP on mouse M phi were characterized and their relationship to the IgG FcR determined. The specific binding of 125I-CRP to resident or elicited mouse M phi was saturable, reversible, and involved both a high and a low affinity receptor population. Binding of CRP to the mouse M phi cell lines PU5 1.8 and J774 was nearly identical to that observed with peritoneal M phi. The high affinity receptor population had a calculated K of 10 nM and a receptor density of approximately 10(5) sites per cell. Mouse Ig of the IgG2a, IgG2b, or IgG1 isotypes inhibited binding of 125I-CRP to PU5 1.8 cells at concentrations five-fold greater than that of the homologous ligand. In the converse experiment, unlabeled CRP failed to inhibit specific binding of 125I-labeled IgG2a, IgG2b or IgG1. Isolation of CRP binding proteins from surface iodinated PU5 1.8 cells by ligand-affinity chromatography or chemical cross-linking yielded a major protein band of 57 to 60 kDa which appeared to be distinct from the IgG1/IgG2b FcR (FcR-II) membrane proteins. Removal of radiolabeled IgG2b/IgG1 binding membrane proteins by affinity chromatography did not remove CRP-binding proteins. The rat mAb 2.4G2 which inhibits binding of radiolabeled mouse IgG2b, did not inhibit the binding of CRP. A rat polyclonal antiserum to CRP-binding membrane proteins of PU5 1.8 cells inhibited 125I-CRP binding, but not 125IgG2b binding. The rat polyclonal antibody reacted with two 57 to 60 kDa membrane proteins from PU5 1.8 cells that appear to be of a similar size on Western blots. The 125I-CRP was internalized via endosomes and intact CRP subunits could be detected intracellularly. The findings suggest that binding of CRP occurs through a receptor that is distinct from the IgG FcRs, but that CRP-R activity may be influenced by an association with an IgG FcR.
The mast cell-committed progenitor. I. Description of a cell capable of IL-3-independent proliferation and differentiation without contact with fibroblasts.
Authors: Jarboe D L , Marshall J S , Randolph T R , Kukolja A , Huff T F 
Published: December 2022

Abstract
We have identified a late, committed stage in the differentiation of the mast cell progenitor just before granulation. Mast cell committed progenitors (MCCP) are nongranulated cells with a density of 1.060 to 1.070 g/ml which can be harvested from the mesenteric lymph node of mice infected with Nippostrongylus brasiliensis. Mast cell-committed progenitors are able to proliferate and differentiate in the absence of IL-3 or IL-4 when cultured on a monolayer of embryonic skin or 3T3 fibroblasts and can form colonies in methylcellulose supplemented with fibroblast conditioned medium. Fibroblast conditioned medium appears to contain a soluble MCCP proliferation factor that maintains biologic activity when heated to 56 degrees C for 45 min but is destroyed by incubation with either trypsin or chymotrypsin. It can be selectively precipitated with 60 to 70% saturated ammonium sulfate. The factor is not absorbed by immobilized antibodies to nerve growth factor. The MCCP proliferation activity of the factor could not be mimicked by IL-1, IL-2, IL-4, granulocyte-macrophage-CSF, granulocyte-CSF, macrophage-CSF, IFN-alpha/beta, IFN-gamma, nerve growth factor, epidermal growth factor, serum fibronectin, heparin, or a number of glycosaminoglycans. At high salt concentrations, the factor passes through a 50-kDa membrane and can be concentrated above a 5-kDa membrane. MCCP acquire a connective tissue phenotype when cultured on a fibroblast monolayer and a mucosal phenotype when cloned in the presence of conditioned medium from PWM-stimulated spleen cells. When cultured in the absence of IL-3 on a monolayer of embryonic skin or 3T3 fibroblasts, mast cell-committed progenitors produce mast cells which stain with berberine sulfate suggesting a connective tissue phenotype; however, the mast cells that develop when mast cell-committed progenitors are cultured in the presence of IL-3 or conditioned media from PWM-stimulated spleen cells do not stain with berberine sulfate. MCCP intercalate into monolayers of embryonic skin or 3T3 fibroblasts, but T cells are not able to associate with the monolayer and can be completely washed away. Attempts to enrich mast cell-committed progenitors by intercalation and elution from embryonic skin monolayers proved unsuccessful, but some enrichment of mast cell-committed progenitors could be achieved by discontinuous Percoll gradients. Thus, we have identified a way to obtain late-stage, mast cell-committed progenitors in an environment that is virtually uncontaminated with other hematopoietic progenitors.
The mast cell-committed progenitor. II. W/Wv mice do not make mast cell-committed progenitors and S1/S1d fibroblasts do not support development of normal mast cell-committed progenitors.
Authors: Jarboe D L , Huff T F 
Published: December 2022

Abstract
We have previously reported that the population of mesenteric lymph node cells from normal BALB/c mice infected 14 days with the rodent nematode Nippostrongylus brasiliensis (Nb-MLN) contains a nongranulated mast cell-committed progenitor (MCCP) which does not require IL-3 for proliferation and differentiation if either a fibroblast monolayer or soluble factors produced by monolayers of 3T3 fibroblasts or embryonic skin are present in the culture. When Nb-MLN were cloned in a methylcellulose culture system using fibroblast conditioned medium as the only source of growth factors, numerous colonies of pure mast cells developed. We wished to determine whether the mast cell deficiency of W/Wv or S1/S1d mice could be explained by the failure of these mice to make either the MCCP or the factor to support proliferation and differentiation of the MCCP. We found that Nb-MLN from W/Wv mice were only able to produce mast cell colonies in response to a source of IL-3 such as conditioned medium from pokeweed mitogen-stimulated spleen cells (CM), and cultures given fibroblast conditioned medium as the only source of growth factors did not produce mast cell colonies. In contrast, Nb-MLN from mast cell deficient S1/S1d mice developed many mast cell colonies in methylcellulose cultures supplemented with either fibroblast conditioned medium or conditioned medium from PWM-stimulated spleen cells. These data suggest that S1/S1d mice but not W/Wv mice produce the mast cell progenitor that responds to fibroblast conditioned medium. To determine if mast cell deficient mice make the fibroblast derived factors that support development of the MCCP, monolayers were prepared from skin connective tissues of S1/S1d and W/Wv mice and Nb-MLN from normal BALB/c mice were cloned in the presence of conditioned medium from these monolayers. Fibroblast conditioned medium from monolayers prepared from W/Wv but not S1/S1d mice supported development of numerous mast cell colonies. Taken together, these data demonstrate that W/Wv mice are incapable of producing normal MCCP whereas S1/S1d fibroblasts fail to produce the appropriate factor to support the MCCP. In accordance with these data, a candidate for the gene product of each of these mutant alleles is discussed.