bluuebunny/crossref_metadata_2025_split huggingface dataset:
Histologic analysis of T lymphocyte activation in reactive lymph nodes.
Authors: Bogen S A , Weinberg D S , Abbas A K 
Published: December 2022

Abstract
As an approach to defining the anatomic sites of T cell activation in situ, we have developed an immunocytochemical stain for IL-2, a T cell-derived cytokine synthesized shortly after Ag-induced activation. Analysis of lymph nodes from mice immunized with keyhole limpet hemocyanin emulsified in CFA demonstrates that the IL2+ cells appear in a perivascular location 4 days after antigenic challenge. After germinal centers develop, IL-2+ cells are situated in a parafollicular pattern. Serial sections stained for different types of APC, including B cells, interdigitating dendritic cells, and macrophages, demonstrate a close physical association between IL-2+ cells and macrophages. These findings may have important implications for defining how APC bearing processed Ag and Ag-specific T cells interact in the complex environment of lymphoid tissues.
IL-4 antagonizes induction of Fc gamma RIII (CD16) expression by transforming growth factor-beta on human monocytes.
Authors: Wong H L , Welch G R , Brandes M E , Wahl S M 
Published: December 2022

Abstract
The multifunctional cytokines, transforming growth factor (TGF)-beta 1 and beta 2, have the capability of inducing human peripheral blood monocytes to express the type III receptor for the Fc portion of IgG (Fc gamma RIII/CD16). In this study we show that the T cell-derived cytokine, IL-4, antagonizes the ability of TGF-beta to induce the expression of CD16. Furthermore, this ability to down-regulate expression of CD16 is completely abrogated after treatment with polyclonal anti-IL-4, suggesting that IL-4 is solely responsible for the observed inhibition. The mechanism for negating the effect of TGF-beta is not due to decreased expression of surface receptors for TGF-beta, but appears to occur at the mRNA level. Nuclear run-off assays indicate that regulation occurs predominantly through a posttranscriptional mechanism(s), although a transcriptional process cannot be ruled out. Normally, CD16 appears on only a small population of circulating monocytes, however, expression is apparent on the majority of mature tissue and inflammatory macrophages likely due to the release of TGF-beta in these sites. Inasmuch as this receptor binds immune complexes and opsonized particles, it is associated with enhanced immunophagocytosis. Suppression of CD16 expression and its ability to suppress a number of other monocyte functions suggests that IL-4 may play an important role in the resolution of inflammatory and tissue repair responses.
Lipoproteins of Borrelia burgdorferi and Treponema pallidum activate cachectin/tumor necrosis factor synthesis. Analysis using a CAT reporter construct.
Authors: Radolf J D , Norgard M V , Brandt M E , Isaacs R D , Thompson P A , Beutler B 
Published: December 2022

Abstract
Lipoproteins from two pathogenic spirochetes (Borrelia burgdorferi and Treponema pallidum) induced the biosynthesis of TNF in murine macrophages and in permanently transformed macrophages of the cell line RAW 264.7. Induction was studied by measuring the secretion of biologically active TNF and by measuring the activity of the reporter enzyme chloramphenicol acetyltransferase (CAT) produced within macrophages transfected with an endotoxin-responsive CAT construct. Several lines of evidence indicated that the induction of TNF and CAT was attributable to the spirochete lipoproteins rather than to contaminating or endogenous LPS: 1) the dose response curves observed for the lipoproteins were markedly different from those obtained with LPS; 2) lipoprotein-mediated activation was unaffected by amounts of polymyxin B that completely neutralized the induction of TNF and CAT by LPS, 3) low concentrations of the lipoproteins induced TNF in macrophages from endotoxin-unresponsive C3H/HeJ mice as effectively as in macrophages from normal C3H/HeN mice, and 4) isolated spirochete lipoproteins, but not a non-lipoprotein immunogen, were potent inducers of CAT in the transformed macrophages. Moreover, LPS was not detected in the B. burgdorferi lipoprotein mixtures by Limulus amebocyte lysate assay. Proteolytic digestion of the intact bacterial protein preparations only modestly diminished their ability to activate the cells, suggesting that small lipopeptides comprise the biologically active portions of the molecules, as is the case with the murein lipoprotein of Escherichia coli. Through their ability to induce TNF production by macrophages, spirochete lipoproteins may play important roles in the development of the local inflammatory changes and the systemic manifestations that characterize syphilis and Lyme disease.
Induction of macrophage inflammatory protein-1 beta gene expression in human monocytes by lipopolysaccharide and IL-7.
Authors: Ziegler S F , Tough T W , Franklin T L , Armitage R J , Alderson M R 
Published: December 2022

Abstract
HuMIP-1 beta is a member of a gene family of inflammatory cytokines whose expression is induced by proinflammatory and mitogenic stimuli. The gene was rapidly induced in human peripheral blood monocytes by either LPS or IL-7. However, IL-7 was unable to induce HuMIP-1 beta mRNA in peripheral blood T cells. The induction of HuMIP-1 beta mRNA in monocytes by IL-7 or LPS was inhibited by IL-4. The 5'-regulatory region of the HuMIP-1 beta gene was cloned and sequenced. An analysis of this sequence revealed three consensus-binding sites for the nuclear factor PU.1 and three potential glucocorticoid response elements. However, the HuMIP-1 beta gene appears to be unresponsive to dexamethasone. Also present in the 5'-regulatory region was a LPS-responsive element located within 455 bp 5' to the start of transcription.
Anti-CD2 receptor antibodies activate the HIV long terminal repeat in T lymphocytes.
Authors: Bressler P , Pantaleo G , Demaria A , Fauci A S 
Published: December 2022

Abstract
The CD2 T lymphocyte glycoprotein surface molecule mediates both cell to cell adhesion and T cell activation, two processes that are involved in the spread of HIV infection. Treatment of chronically HIV-infected PBMC with anti-CD2 mAb has been shown to induce the expression of infectious virus from these cultures. In this study we investigated the mechanisms whereby anti-CD2 antibodies stimulate viral production. We demonstrate that treatment of transiently transfected T lymphocytes with anti-CD2 antibodies results in activation of the HIV long terminal repeat. Furthermore, CAT assays using mutated HIV long terminal repeat-CAT constructs and gel shift assays demonstrate that this activation is dependent on the NF-kappa B enhancer. These studies suggest that interaction of CD2 with its natural ligand, LFA-3, may play a role in regulation of HIV expression.
Human T cell activation by OKT3 is inhibited by a monoclonal antibody to CD44.
Authors: Rothman B L , Blue M L , Kelley K A , Wunderlich D , Mierz D V , Aune T M 
Published: December 2022

Abstract
The CD44 molecule, also known as Hermes lymphocyte homing receptor, human Pgp-1, and extracellular matrix receptor III, has been shown to play a role in T cell adhesion and activation. Specifically, anti-CD44 mAb block binding of lymphocytes to high endothelial venules, inhibit T cell-E rosetting, and augment T cell proliferation induced by the CD2 or CD3-TCR pathways. We have characterized an anti-CD44 mAb (212.3) which immunoprecipitates a 90-kDa protein and is specific for CD44 as shown by peptide mapping and antibody competition studies. Interestingly, our studies with 212.3 demonstrate that this CD44-specific mAb completely inhibits T cell proliferation stimulated by the anti-CD3 mAb, OKT3. Inhibition is not a result of reduced cell viability, but is associated with 1) inhibition of IL-2 production, 2) inhibition of IL-2R expression, and 3) inhibition of OKT3-mediated increases in intracellular Ca2+ levels. In addition, 212.3 does not inhibit proliferation by the T cell mitogens PHA or PWM nor does it inhibit proliferation in a mixed lymphocyte reaction. Similar to other anti-CD44 mAb, 212.3 also augments T cell proliferation induced by mAb directed against the T11(2) and T11(3) epitopes of CD2. Thus, these studies describe a novel CD44-specific mAb (212.3) that inhibits T cell activation by OKT3 by blocking early signal transduction. Furthermore, these studies suggest that "receptor cross-talk" between the CD3-TCR complex and CD44 may regulate T cell activation.
Activation of guinea pig eosinophils by human recombinant IL-5. Selective priming to platelet-activating factor-acether and interference of its antagonists.
Authors: Coëffier E , Joseph D , Vargaftig B B 
Published: December 2022

Abstract
The potential role of platelet-activating factor (PAF)-acether and of IL-5 as an eosinophil-proliferating, activating, and/or recruiting mediator in asthma led us to study the effects of human (h) rIL-5 (hrIL-5) and PAF-acether, alone or combined, on isolated guinea pig eosinophils. Two populations of eosinophils were separated from peritoneal lavages of polymyxin B-treated guinea pigs upon a discontinuous metrizamide gradient: one of low density (between 20 and 22% of metrizamide, purity: 63 +/- 3%, n = 27) and another of normal density (between 22 and 24% of metrizamide, purity: 87 +/- 2%, n = 16). Chemotactic activity was evaluated on a micro-Boyden chamber, results being expressed as the number of migrating eosinophils (mean +/- SEM) at 40 microns through a cellulose nitrate filter (3 microns pore size) in the presence of the agonist or of the solvent alone. hrIL-5 dose-dependently stimulated normodense eosinophil chemotaxis, reaching a peak at 500 ng/ml (98 +/- 21 migrating eosinophils, n = 5, p less than 0.05). These eosinophils also responded to PAF-acether and to LTB4 and not to FMLP, hrTNF alpha, and LPS. Eosinophil preincubation with hrIL-5 increased significantly the migration by PAF-acether (173 +/- 23 migrating eosinophils with PAF-acether 10 nM after preincubation with hrIL-5 500 ng/ml vs 69 +/- 10 after preincubation with buffer alone, p less than 0.01) and failed to enhance migration by LTB4 or to uncover an activity for FMLP. Migration by PAF-acether was antagonized when the cells were preincubated with the antagonists BN 52021 and WEB 2086, which also inhibited migration by hrIL-5. Eosinophils were auto-desensitized by and to PAF-acether or LTB4, but were not cross-desensitized to each other. Eosinophils desensitized to PAF-acether failed to migrate with hrIL-5, but those desensitized to LTB4 responded to hrIL-5 as controls. hrIL-5 failed to induce the elevation of intracellular free calcium concentration and superoxide anion generation from basal values, whereas preincubation of eosinophils with hrIL-5 induced a significant increase in the rise in intracellular free calcium concentration and in superoxide anion generation by 10 nM PAF-acether but not by LTB4. In conclusion, the in vivo eosinophil migration in allergy may involve hrIL-5, particularly associated to PAF-acether.
A frameshift mutation at the NH2 terminus of the nucleoprotein gene does not affect generation of cytotoxic T lymphocyte epitopes.
Authors: Fetten J V , Roy N , Gilboa E 
Published: December 2022

Abstract
BALB/3T3 cells infected with a retroviral vector encoding the influenza virus nucleoprotein (NP) gene are efficiently lysed by CTL generated in BALB/c mice (H-2d background). Cells transduced with a mutant form of NP which contains a frameshift mutation at its NH2 terminus (NPm) do not express biochemically detectable levels of protein but nevertheless present Ag to CTL with high efficiency. Cold target inhibition studies indicate that the same CTL epitope(s) are recognized in cells harboring NP or NPm. L929 cells transduced with the NPm gene also present Ag efficiently to CTL raised in C3H mice (H-2k background). Cells engineered to express 5- to 15-fold lower levels of wild-type NP were not capable of presenting Ag to CTL, arguing against the notion that CTL are able to lyse cells expressing very low levels of Ag which might have resulted from suppression of the frameshift mutation in NPm. Implications to the mechanism of epitope generation in class I MHC-restricted immune responses are considered.
Cellular models of macrophage tumoricidal effector mechanisms in vitro. Characterization of cytolytic responses to tumor necrosis factor and nitric oxide pathways in vitro.
Authors: Klostergaard J , Leroux M E , Hung M C 
Published: December 2022

Abstract
The recently described L-arginine-dependent nitric oxide (NO) pathway has been proposed to interact synergistically with the TNF pathway in murine macrophage-mediated tumor cytotoxicity in vitro. We have employed an experimental construct in which these two pathways were independently expressed by two different effector cell populations. The TNF-dependent pathway was committed by murine 3T3 cells transfected with the cDNA encoding human pro-TNF. The NO pathway was executed by the murine EMT-6 mammary adenocarcinoma cell line treated with murine rIFN-gamma and LPS. Controls for the TNF pathway committed by the transfectant included lysis of the TNF-sensitive murine L929 cell in coculture, secretion of TNF, and absence of nitrite synthesis. For the NO pathway controls included lysis of the murine P815 mastocytoma cocultured with activated EMT-6 cells that had been pretreated with murine rIFN-gamma and LPS, production of nitrite by this activated effector cell, and an absence of TNF secretion. The target cell panel included L929, EMT-6, P815, and murine B16 melanoma and TU-5 sarcoma cell lines. All targets on this panel were susceptible to lysis by LPS-triggered murine bacillus Calmette-Guérin-activated macrophages. The 3T3 transfectant caused significant lysis of cocultured L929 and TU-5 targets. The EMT-6 effector cell only caused significant lysis of the P815 target. When both effector cells were cocultured with these target cells, lysis of the P815 target was observed to be additive or superadditive; however, for all the other targets, cytotoxicity was comparable with or subadditive compared with that seen with the 3T3 transfectant effector cell alone. Thus, these two pathways do not appear to account for the broad, potent tumoricidal activity observed for activated macrophages in vitro.
Differential sensitivity of virgin and memory T lymphocytes to calcium ionophores suggests a buoyant density separation method and a model for memory cell hyporesponsiveness to Con A.
Authors: Miller R A , Flurkey K , Molloy M , Luby T , Stadecker M J 
Published: December 2022

Abstract
Previous work from this laboratory has indicated that murine memory T cells differ from virgin T cells in that the former are more resistant to agents that alter intracellular [Ca]i. We have used this difference to devise a method for separating virgin from memory T cells by centrifugation over an ionomycin-containing Percoll step gradient after brief exposure to 2 microM ionomycin. Under these conditions, those T cells that are most sensitive to ionomycin-induced changes in [Ca]i become more dense and therefore travel further into the Percoll/ionomycin gradient than cells that are more resistant to ionomycin. We show that the ionomycin-resistant cell population is enriched for cells that express high levels of Pgp-1 (CD44), and low levels of CD45RB, and thus appears to consist largely of memory T cells. Both CD4 and CD8 cells can be divided into Pgp-1hi and Pgp-1lo subsets in this way. Cells recovered from such a gradient and washed to remove the ionomycin appear normally functional, i.e., neither more nor less responsive to mitogens and costimuli than untreated cells. Limiting dilution methods show that the ionomycin-sensitive (virgin) subset contains most of the Con A-responsive precursors for cytotoxicity, and most of the cells able to produce IL-2 in responses to Con A or staphylococcal enterotoxin B. Ag-specific helper memory cells are, however, found predominantly in the ionomycin-resistant fraction of the spleen and draining lymph nodes of mice infected with Schistosoma mansoni. Changes in resistance to calcium signal development may represent a fundamental distinction between virgin and memory T cells, and could contribute to differences in activation requirements between these two cell subsets.
Ig V kappa family repertoire of plasma cells derived from autoimmune MRL mice.
Authors: Teale J M , Sievers K M , Crawley R R , Kotzin B L 
Published: December 2022

Abstract
V kappa gene family usage was determined in the resident in vivo-activated plasma cells of individual diseased MRL mice by using in situ hybridization. In this way, the entire autoimmune repertoire could be analyzed. Autoantibody levels and extent of glomerulonephritis were also measured, so that the severity of disease could be assessed. It was found that V kappa expression was highly variable from mouse to mouse. Some animals displayed a V kappa family repertoire similar to mitogen-stimulated cells and consistent with the size of the families. These animals tended to have lower disease indices. Other animals, which had higher disease indices, displayed considerable over- or underutilization of individual V kappa families. However, no particular V kappa families were repeatedly biased in their expression, as was found at the VH level with J558. Importantly, in the 10% of animals that expressed VH J558 exclusively, four or more V kappa families were expressed and multiple antiself specificities were produced. The data are most consistent with a number of J558 genes being expanded in a variety of self-specificities. However, because only VH J558 is expressed in these sicker animals, nonspecific polyclonal activation is highly unlikely. These results underscore the continuing evolution of the autoimmune repertoire, with considerable diversity at early stages followed by a highly selected repertoire in which a potential role for nonspecific polyclonal activation is virtually excluded.
Effect of recombinant IFN-gamma (rIFN-gamma) on the mechanism of human macrophage IgG FcRI-mediated cytotoxicity. rIFN-gamma decreases inhibition by cytophilic human IgG and changes the cytolytic mechanism.
Authors: Van Schie R C , Verstraten R G , Van de Winkel J G , Tax W J , de Mulder P H 
Published: December 2022

Abstract
Different classes of receptors for the Fc moiety of IgG (Fc gamma R) have been defined on human monocytes and macrophages: Fc gamma RI, Fc gamma RII, and Fc gamma RIII. All three classes are capable of mediating antibody-dependent cell-mediated cytotoxicity (ADCC). Fc gamma RI, which binds monomeric human IgG (hIgG) with high affinity, was shown an effective cytotoxic trigger molecule on different types of cells. In vitro, the inhibition of Fc gamma RI-mediated ADCC by hIgG is well documented. The low affinity receptor classes, Fc gamma RII and Fc gamma RIII, are not blocked by monomeric hIgG. Because monomeric hIgG is present at high concentrations in plasma and interstitial fluids it has been postulated inhibitory in vivo. We investigated the effect of rIFN-gamma on macrophage Fc gamma RI-mediated ADCC in the presence of low doses hIgG. With human E sensitized with hIgG as target cells, Fc gamma RI was studied selectively. We found that rIFN-gamma enhances both expression and cell surface density of Fc gamma RI on cultured peripheral blood monocytes. Furthermore, this cytokine partially reversed the inhibitory effect of monomeric hIgG on ADCC. More interestingly, we found that the cytolytic mechanism of monocyte-derived macrophages changed completely after prolonged culture with rIFN-gamma. Monocytes cultured for 9 days in control medium mediate predominantly phagocytosis. After long term rIFN-gamma stimulation (9 days), monocyte-derived macrophages almost completely lost the capacity to perform phagocytosis. Interestingly, they became highly efficient in mediating extracellular lysis of human E sensitized with hIgG. Short term rIFN-gamma stimulated monocyte-derived macrophages (for the last 40 h of culture) were found to mediate both phagocytosis and extracellular lysis. Our findings suggest that in vivo rIFN-gamma-stimulated macrophages may be most efficient in Fc gamma RI-mediated cytolysis as a consequence of a changed cytolytic mechanism in combination with enhanced Fc gamma RI density.
T lymphocytes mediating protection and cellular cytolysis during the course of Mycobacterium tuberculosis infection. Evidence for different kinetics and recognition of a wide spectrum of protein antigens.
Authors: Orme I M , Miller E S , Roberts A D , Furney S K , Griffin J P , Dobos K M , Chi D , Rivoire B , Brennan P J 
Published: December 2022

Abstract
Recent evidence suggests the existence of at least two pathways of acquired specific resistance to Mycobacterium tuberculosis infection; the first consisting of cytokine-mediated activation of parasitized host cells by protective T cells, and the second involving the lysis of these cells by cytolytic T cells. Evidence presented in this report shows that both of the above mechanisms are operative in experimentally infected mice, but that they differ markedly in terms of their kinetics of emergence and loss. It was found that protective T cell activity was acquired very early during the course of the infection, and was temporally associated with the onset of bacterial elimination; however, cytolytic activity did not peak until 10 to 20 days later. This report shows further that the target Ag of these effector T cell populations were apparently numerous with no evidence for preferential recognition of a few immunodominant Ag. In view of the preponderance of target proteins in the bacterial filtrate, we present the hypothesis that such proteins secreted or otherwise leaked from the dividing mycobacterium are pinocytosed from the phagosome and used by the infected macrophage as the key protective Ag leading to T cell sensitization. This hypothesis thus explains the preferential requirement for the viable bacterium in the generation of specific resistance, and further explains why protective immunity is generated even while the organism is still multiplying in an apparently unrestrained manner.
IL-6 induced by IL-1 inhibits malaria pre-erythrocytic stages but its secretion is down-regulated by the parasite.
Authors: Pied S , Civas A , Berlot-Picard F , Renia L , Miltgen F , Gentilini M , Doly J , Mazier D 
Published: December 2022

Abstract
The capacity of IL-6 to mediate the antiparasitic activity of IL-1 on intrahepatic development of malaria parasite was demonstrated. The comparisons of IL-6 levels in infected and noninfected hepatocyte cultures, either purified or enriched with nonparenchymal cells and stimulated by IL-1 or IL-6, indicate that subtle interactions exist between intrahepatocytic development of Plasmodium yoelii and liver synthesis of IL-6. During its intrahepatic multiplication, the parasite causes a decline in IL-6 production. IL-6 mRNA was not detected in the livers of infected mice during development of either hepatic or blood stage parasites although IL-6 activity was found in the sera during both stages.