bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of human perforin in a mouse cytotoxic T lymphocyte cell line: evidence for perturbation of granule-mediated cytotoxicity
Authors: Thia Kevin Y T , Smyth Mark J , Trapani Joseph A 
Published: January 2018

Abstract
Expression of the pore-forming protein perforin is normally restricted to the cytolytic granules of cytotoxic T lymphocytes and natural killer cells. Perforin, which causes cell death by osmotic lysis, has the ability to form transmembrane channels in target cell membranes. This function makes perforin crucial in the granule-exocytosis model of T cell-mediated cytotoxicity. In the present study, variants of the mouse cytotoxic T lymphocyte cell line CTLL-R8 have been produced which express human perforin. A full-length cDNA clone (HP-10) encoding human perforin was inserted in the sense orientation into the expression plasmid pCMV5neo. The resultant construct, designated pCMV5neoHP-10, was used to transfect GTLL-R8 cells. Of eight G418-resistant clones studied, four clones expressed human perforin mRNA by Northern analysis and three of these clones also expressed human perforin protein by Western blotting. The expression of human perforin protein was associated with a pronounced (55-74%) and consistent reduction in the killing of three target cell lines, P815, YAC-1, and EL4, compared with parental GTLL-R8 cells. The reduction in target cell lysis could not be attributed to nonspecific effects of the transfection, as clones transfected with neo alone showed no reduction in killing in comparison with parental GTLL-R8 cells. Clones expressing human perforin showed very similar growth characteristics, surface phenotype, and 2 N-α- benzyloxycarbonyl-L-thiobenzyl-esterase release compared with untransfected CTLL-R8 cells. The mechanism of reduction of cytolysis is unclear but may involve competition by human perforin in the handling or packaging of endogenous granule constituents (including mouse perforin) or assembly of human perforin into mouse polyperforin channels in target cell membranes. The expression of human perforin in mouse cytotoxic T cells provides a potential model for studying how cytotoxic T cells process, package, utilize, and protect themselves against the perforin molecules they produce.
Effects of macrophage colony-stimulating factor (M-CSF) on the development, differentiation, and maturation of marginal metallophilic macrophages and marginal zone macrophages in the spleen of osteopetrosis (op) mutant mice lacking functional M-CSF activity
Authors: Takahashi Kiyoshi , Umeda Syuji , Shultz Leonard D , Hayashi Shin-Ichi , Nishikawa Shin-Ichi 
Published: January 2018

Abstract
Immunohistochemical techniques using an anti-mouse panmacrophage monoclonal antibody and anti-mouse monoclonal antibodies specific for marginal metallophilic macrophages or marginal zone macrophages were used to detect red pulp macrophages, marginal metallophilic macrophages, and marginal zone macrophages in the spleen of op/op mice. In the mutant mice, the red pulp macrophages were reduced to about 60% of those in the normal littermates and the marginal metallophilic macrophages and marginal zone macrophages were absent. After administration of recombinant human macrophage colony-stimulating factor (rhM-CSF), numbers of red pulp macrophages increased rapidly, reaching levels found in normal littermates 1 week later. In contrast, the marginal metallophilic macrophages as well as the marginal zone macrophages appeared slowly after rhM-CSF administration and their numbers were less than half of the baseline level of normal littermates even at 12 weeks of administration. The distribution of marginal metallophilic macrophages and marginal zone macrophages appearing after M-CSF administration was irregular in the spleen of the op/op mice. These splenic macrophage subpopulations differed in their responses to rhM-CSF, suggesting that distinct mechanisms may be involved in their development and differentiation. The splenic red pulp macrophages present in unmanipulated op/op mice are an M-CSF–independent macrophage population. Although the marginal metallophilic macrophages and marginal zone macrophages are thought to be M-CSF-dependent, their development and differentiation appear to be influenced by locally produced M-CSF or other cytokines. J. Leukoc. Biol. 55: 581-588; 1994.
Effect of thioglycollate and BCG stimuli on glucose and glutamine metabolism in rat macrophages
Authors: Costa Rosa L F B P , Safi D A , Curi R 
Published: January 2018

Abstract
The macrophage is a differentiated cell that takes part in a wide range of physiological and pathological processes, such as inflammatory and immunological responses. The stimulation of macrophages involves the acquisition of some functional characteristics such as phagocytosis, ability to kill tumor cells, and processing and presentation of antigens. In this study we have investigated the changes in macrophage glucose and glutamine metabolism as induced by stimulation by thioglycollate (inflammatory) and bacille Calmette-Guérin (BCG) (activated). The results showed an increase in hexokinase and citrate synthase activities, due to both stimulatory processes. One difference between inflammatory and activated cells is the higher rate of glucose oxidation in the latter. The activation with BCG, however, also led to an enhancement in glutamine metabolism that is not observed in the inflammatory cell. These results suggest that glutamine metabolism might be important for macrophage function during immunological response. J. Leukoc. Biol. 56: 10–14; 1994.
Interaction of nuclear proteins with an AP-1/CRE-like promoter sequence in the human TNF-α gene
Authors: Newell Christine L , Deisseroth Albert B , Lopez-Berestein Gabriel 
Published: January 2018

Abstract
The tumor necrosis factor α (TNF-α) promoter contains an AP-l/CRE-like binding site, TGAGCTCA. AP-1 elements generally transduce signals involving protein kinase C; the CRE site mediates a cAMP response, involving protein kinase A. Thus, this element has the potential to receive signals through divergent signaling pathways. Nuclear protein binding studies using extracts from THP-1 monocytic cells treated with lipopolysaccharide (LPS), which stimulates, or dexamethasone (Dex) or pentoxifylline (PTX), which inhibit TNF production, respectively, suggest that two lowmobility complexes could be involved in regulation through this promoter region. PTX and Dex increase binding of both these complexes compared with untreated cells; approximately 2 hours after LPS induction, the upper complex becomes undetectable. This upper complex is composed of ATF2 (activating transcription factor 2, a cyclic AMP responsive element binding protein) homodimers; the lower is a heterodimer of jun/ATF2. LPS induces c-jun and thus may enhance formation of jun/ATF2 complexes, which could be activating complexes. In this case, the simultaneous presence of both complexes, which would occur in the presence of Dex or PTX, could reduce the amount of TNF transcription through competitive binding. Through in vitro competitive binding studies comparing the binding affinities of the TNF promoter sequence and a consensus CRE, we further suggest how variation of endogenous binding sequences from consensus may be an important property for regulatory control of particular genes J. Leukoc. Biol. 56: 27–35; 1994.
Effect of the carbocyclic nucleoside analogue MDL 201,112 on inhibition of interferon-γ-induced priming of Lewis (LEW/N) rat macrophages for enhanced respiratory burst and MHC class II Ia+ antigen expression
Authors: Edwards Carl K , Watts Lynnetta M , Parmely Michael J , Linnik Matthew D , Long Richard E , Borcherding David R 
Published: January 2018

Abstract
The effects of the carbocyclic nucleoside MDL 201,112 and the purine nucleoside adenosine on the interferon-γ (IFN-γ)-induced priming of macrophages (mfs) for the respiratory burst and major histocompatibility class II (MHC class II) Ia+ antigen expression were compared. Priming of purified, peritoneal mφs from Lewis (LEW/N) rats for 18 h with recombinant rat IFN-γ (rRaIFN-γ) in the presence of either adenosine (100 μM) or MDL 201,112 (10 μM) resulted in a fourfold decrease in superoxide anion (02-) production after stimulation with opsonized zymosan. Both agents were effective even when added 2 or 4 h after rRaIFN-γ treatment. Peritoneal mφs from LEW/N rats stimulated with LPS/rRaIFN-γ were observed to secrete immunoreactive and bioactive TNF-α over 18 h in vitro and this cytokine could be dose-dependently inhibited by MDL 201,112. MDL 201,112 did not bind to classical A1 or A2 receptors on rat brain homogenates. Physiological levels of adenosine deaminase, or treatment with the nucleoside transport inhibitor dipyridamole, reversed the effects of adenosine; however, these agents at physiological concentrations had little or no effect on the inhibition of 02- release mediated by MDL 201,112. Furthermore, incubation of LEW/N mφs for 18 h in vitro with rRaIFN-γ resulted in significant enhancement of MHC class II Ia+ antigen expression, and these levels could be blocked by nearly 50% by either MDL 201,112 (10 μM) or adenosine (100 μM). MDL 201,112 and adenosine were also effective in decreasing mφ opsonized zymosan-stimulated 02- levels and MHC class II Ia+ antigen expression in vivo. The effects of MDL 201,112 on the down-regulation of heat-killed M. tuberculosis-activated LEW/N mφ MHC class II Ia+ antigen expression in vitro appear to be mediated by a novel pathway, because there was no rank order of potency of ADO A1 or A2 agonist/antagonists (CCPA, NECA, XAC, or CPT) in our in vitro system. In summary, our data provide compelling evidence that immunoregulatory carbocyclic nucleoside analogues such as MDL 201,112 or adenosine appear to regulate LEW/N rat mf activation through novel molecular mechanisms and may have important therapeutic implications for acute and chronic inflammatory diseases. J. Leukoc. Biol. 56: 133–144; 1994.
Glucosidase trimming inhibitors preferentially perturb T cell activation induced by CD2 mAb
Authors: van Kemenade F J , Rotteveel F T M , van den Broek L A G M , Baars P A , van Lier R A W , Miedema F 
Published: January 2018

Abstract
Glycosidase trimming inhibitors may be used to study contribution of N-linked glycan moieties in T cell function. We have studied the effects of castanospermine (Cas), swainsonine (Swain), 1-deoxynojirimycin (dNM), and 1-deoxymannojirimycin (dMM) on T cell activation and differentiation. Our analysis included a new dNM derivative, N-pentyl-1-deoxynojirimycin (pentyldNM). Previous reports showed inhibitory action of trimming inhibitors, such as Swain and Cas, on pokeweed mitogen-driven immunoglobulin (Ig) production. We extend these findings for pentyldNM and observed that glucosidase inhibitors, Cas and pentyldNM were effective in inhibiting CD2 and CD3 monoclonal antibody (mAb) driven Ig production. The pattern of inhibition by mannosidase and glucosidase inhibitors correlated with inhibitory action on T cell activation: only glucosidase trimming inhibitors (Cas and pentyldNM with comparable potency) perturbed mAb-induced T cell activation, in particular if induced by CD2 mAb. Expression of the early activation marker CD69 was not decreased in the presence of these inhibitors, while addition of exogenous recombinant interleukin-2 partially overcame inhibitory effects during proliferation. These findings suggest that glucosidase, but not mannosidase, trimming inhibitors interfere with a late phase of T cell activation. In addition, the enhanced sensitivity of CD2 mAb-induced proliferation for glucosidase trimming inhibitors suggests dependence on N-linked glycans during CD2-mediated adhesion and triggering functions. J. Leukoc. Biol. 56: 159–165; 1994.
Variables in the isolation and culture of human monocytes that are of particular relevance to studies of HIV
Authors: Bennett Suzanne , Breit Samuel N 
Published: January 2018

Abstract
Mononuclear phagocytes play an important role in human immunodeficiency virus (HIV) infection. However, knowledge of the extent of macrophage involvement in the pathogenesis of HIV infection is still incomplete. This is due in part to the technical difficulties associated with isolating, purifying, and culturing these cells. Isolation of a pure population of human monocytes is essential when studying the role of these cells in HIV infection. In addition, the differentiation, activation, and replication of human monocytes are critically affected by both isolation and culture conditions. This review examines the different monocyte isolation and purification methods and culture conditions that are currently being employed and assesses their suitability for studying the functions of monocytes in HIV infection. J. Leukoc. Biol. 56: 236–240; 1994.
HIV protease inhibitors: effects on viral maturation and physiologic function in macrophages
Authors: Bugelski Peter J , Kirsh Richard , Hart Timothy K 
Published: January 2018

Abstract
Human immunodeficiency virus (HIV), the retrovirus believed to be the cause of acquired immunodeficiency syndrome (AIDS), infects a variety of CD4+ cells, including lymphocytes and cells of the monocyte/macrophage lineage. Encoded in the HIV genome are several precursor proteins that must undergo proteolytic cleavage to yield functional proteins. The gag precursor protein of HIV (p55) is cleaved by a virally encoded aspartate protease (HIV protease). Because cleavage of p55 is required for viral maturation and infectivity, inhibition of HIV protease is an attractive target for therapy designed to block the progression of HIV infection. Inhibitors of HIV protease from a variety of chemical classes have been synthesized and antiviral activity has been demonstrated in lymphocytes and cells from the monocyte/macrophage lineage. A few HIV protease inhibitors have progressed to the clinic and some have shown promise in early trials. There are, however, several important issues that will affect the development of a successful HIV protease inhibitor, including cell and tissue distribution and immunotoxicity. These issues are discussed, with an emphasis on the complexities posed by cells of the monocyte/macrophage lineage. J. Leukoc. Biol. 56: 374–380; 1994.
Macrophages/microglia and the pathophysiology of CNS injuries in AIDS
Authors: Gendelman Howard E , Tardieu Marc 
Published: January 2018

Abstract
How HIV-1 penetrates the central nervous system (CNS) and induces neurological disease remains poorly understood. Clinical and pathological consequences of HIV-1 associated CNS infections are the subjects of a relatively new field comprising a spectrum of many brain diseases including those that are HIV-1 associated or secondary to bacterial, fungal, protozoal, or tumor infiltration of brain. The molecular and biological approaches used to study HIV-1-mediated brain disease are interdisciplinary. A wide variety of expertise and cooperative research efforts is required between molecular virologists, cellular immunologists, and neurobiologists. Indeed, specialists studying microglial maturation, astrocyte function, neurotoxicity, HIV-1 neurovirulence, and apoptosis all play pivotal roles in examining facets of this disease complex.
Production of nitric oxide by differentiated LSTRA cells is associated with expression of macrophage-inducible nitric oxide synthase
Authors: Garcia-Welsh Adrienne , Laskin Debra L , Hwang Shiaw-min , Denhardt David T , Laskin Jeffrey D 
Published: January 2018

Abstract
LSTRA is a mouse lymphoma cell line overexpressing the src-related oncogene product and T cell marker p56lck. We have discovered that LSTRA cells, like HL60 and U937 promyelocytic leukemia cells, can be induced to differentiate toward macrophages by the phorbol ester 12-O-tetradecanoyl phorbol-13-acetate (TPA) or granulocytes by the cyclic nucleotide analogue dibutyryl cAMP (dbcAMP). One property of mature macrophages and granulocytes is the ability to produce nitric oxide, a highly reactive free radical that is important in non-specific host defense. Nitric oxide production by mature macrophages is stimulated by inflammatory mediators via an inducible form of the enzyme, nitric oxide synthase. We report that LSTRA cells acquire the ability to produce nitric oxide following differentiation induced by TPA and, to a lesser extent, by dbcAMP. Nitric oxide production by the cells is dependent on l-aiginine and blocked by several inhibitors of nitric oxide synthase, including N-monomethyl-l-arginine, l-canavanine, l-arginine benzyl ester, and l-arginine methyl ester. In macrophage-differentiated LSTRA cells, the inflammatory cytokine interferon-γ was found to be a potent inducer of nitric oxide production. This was correlated with a marked increase in nitric oxide synthase activity in the cells that was due to interferon-γ-induced expression of the macrophage-inducible form of nitric oxide synthase protein as well as mRNA. Differentiated LSTRA cells also expressed increased amounts of a constitutive form of nitric oxide synthase that was also present in undifferentiated cells. Taken together with previous findings, these results support the model that LSTRA cells have the capacity to differentiate toward mature macrophages. J. Leukoc. Biol. 56: 488–494; 1994.
Role of proteasomes modified by interferon-γ in antigen processing
Authors: Tanaka Keiji 
Published: January 2018

Abstract
Large multisubunit proteasomal complexes, catalyzing an extralysosomal, ATP-dependent pathway for selective degradation of unnecessary proteins, are thought to be responsible for major histocompatibility complex (MHC) class I–restricted antigen presentation. Two proteasomal polymorphic genes, LMP2 and LMP7, are localized within the MHC class II region, closely linked to the TAPI and TAP2 genes that are responsible for the ATP-dependent, size- and sequence-selective transport of antigenic peptides generated in the cytoplasm into the endoplasmic reticulum. Interferon-γ (IFN-γ) alters the peptide-degrading specificity of proteasomes and appears to produce an immunoproteasome responsible for accelerated processing of nonself endogenous antigens by inducing the replacement of subunits X and Y by LMP7 and LMP2, respectively. This IFN-γ-induced change in the subunits of proteasomes by IFN-γ is a new mechanism for an immunomodulatory action, differing from that for marked increases of TAP transporter and MHC molecules, which are possibly due to changes in transcriptional levels in cells. Based on these findings, I propose alteration of the subunit assembly of proteasomes in response to extracellular stimuli as a novel mechanism for the acquisition of their functional diversity that plays a central role in the immune response. J. Leukoc. Biol. 56: 571–575; 1994.
Identification and characterization of a bovine lipopolysaccharide-binding protein
Authors: Khemlani Lajwanti S , Yang Zhengang , Bochsler Philip N 
Published: January 2018

Abstract
Endogenous regulatory mechanisms exist in mammals that enable a rapid response to lipopolysaccharide (LPS, endotoxin) stemming from gram-negative bacterial infections. Serum proteins and cell surface receptors exist that bind LPS, and this interaction may either aid in nonpathogenic removal of LPS from the body or potentiate the effects of LPS. We have used a photoreactive, thiol-cleavable, radiolabeled derivative of E. coli 0111:B4 LPS [LPS-(p-azidosalicylamido)-1,3′-dithiopro-pionamide; 125I-ASD-LPS], to identify the presence of LPS-binding proteins (LBPs) in bovine serum. Ion exchange chromatography was used to fractionate bovine serum, and eluted protein was subsequently photoaffinity labeled using 125I-ASD-LPS. LBPs were identified by autoradiography of sodium dodecyl sulfate-polyacrylamide gels. Several LBPs including three with apparent molecular masses of 65, 60, and 50 kDa were variably present within the chromatography pools. A 22-residue NH2-terminal amino acid sequence of the 60-kDa protein showed 77% homology with human LBP and 68% with rabbit LBP within this region. Further purification utilizing high-performance liquid chromatography yielded a protein fraction that contained the 60-kDa protein and was distinctly more active than whole bovine serum in LPS-dependent macrophage activation assays (up to 1600-fold on a weight/volume basis). The LPS-mediated macrophage activation in concert with chromatographically purified serum protein in tissue factor assays was inhibitable using anti-CD14 monoclonal antibodies. The results indicate that an LPS-binding protein exists in samples of pooled bovine serum and that this protein has features in common with human and rabbit LBP. J. Leukoc. Biol. 56: 784–791; 1994.
Influence of age on the production of Fos and Jun by influenza virus-exposed T cells
Authors: Salkind Alan R 
Published: January 2018

Abstract
This study investigated age-related T cell responses after in vitro exposure to influenza A virus. Mononuclear leukocytes from young or elderly persons were sham-exposed or exposed to influenza virus for 1, 24, and 72 h. Immunofluorescent staining and flow cytometric analysis were then used to detect T cells producing the transcriptional regulating proteins Fos and Jun. Fewer virus-exposed cells from elderly donors stained for Fos and Jun at each data point compared with cells from young donors. Flow cytometric analysis also showed that at 72 h of virus exposure fewer T cells from the elderly produced interferon-gamma (IFN-γ), suggesting a link between the magnitude of the Fos and Jun and IFN-γ responses. Thus, failure of virus-exposed T cells to produce Fos and Jun could contribute to the increase in illness due to influenza virus in the elderly. J. Leukoc. Biol. 56: 817–820; 1994.
Loss of response to β-adrenoceptor agonists during the maturation of human monocytes to macrophages in vitro
Authors: Baker A J , Fuller R W 
Published: January 2018

Abstract
We have previously reported that human airway macrophages do not respond to the β-adrenoceptor agonist isoprenaline. The airway macrophage is known to be derived from the blood monocyte. In this study we have assessed the effect of β-adrenoceptor stimulation on human monocytes matured into macrophages in vitro, to determine whether the lack of response previously observed in the airway macrophage may be a consequence of differentiation. The release of thromboxane B2 (TXB2) from freshly isolated monocytes stimulated by opsonized zymosan (OPZ) was inhibited by 39.3 ± 5.5% in the presence of isoprenaline (10-7 M). However, the response was lost in the monocyte-derived macrophage (MDM), where isoprenaline (10-7 M) caused only 4.0 ± 9.3% inhibition of OPZ-stimulated TXB2 release. In contrast forskolin (10-5 M) inhibited MDM TXB2 release by 36.4 ± 17.3%, indicating that the adenylyl cyclase was functional. Measurement of adenylyl cyclase activity showed that there was a reduction in the basal level, 17.03 ± 4.1 to 7.9 ± 4.6 cyclic AMP pmol/min/mg protein, and NaF (10-2 M)-induced activity, 116.3 ± 32.1 to 21.9 ± 12.6 cyclic AMP pmol/min/mg protein, between freshly isolated monocytes and MDMs, respectively. In addition, there was no change in MDM basal adenylyl cyclase activity on exposure to isoprenaline. Thus we have demonstrated the loss of β-adrenoceptor function during the maturation of human monocytes to macrophages in vitro, despite a functional adenylyl cyclase system. In this respect the monocyte-derived macrophage is like the airway macrophage. J. Leukoc. Biol. 57: 395–400; 1995.