bluuebunny/crossref_metadata_2025 huggingface dataset:
Cellular depletion of p56lck during thymocyte apoptosis
Authors: Garcia-Welsh Adrienne , Laskin Debra L , Shuler Randy L , Laskin Jeffrey D
Published: January 2018

The src-related protein tyrosine kinase p56lck is thought to be important in regulating maturation and functional responsiveness of T cells and thymocytes. In the present studies we report that expression of p56lck is suppressed during apoptosis. Using primary cultures of rat thymocytes, we found that agents that are effective in inducing apoptosis, including okadaic acid, dexamethasone, and antibodies to the CD3 receptor, also deplete cells of p56lck. This process is rapid, occurring within 24 h, and is not due to cytotoxicity. Inhibition of DNA fragmentation in apoptotic cells with the endonuclease inhibitor ZnCl2 failed to prevent depletion of p56lck, suggesting that it was not a consequence of the DNA degradation process. Using the thymic lymphoma cell line LSTRA, apoptosis was also associated with cellular depletion of p56. In contrast to thymocytes, this process required 48–72 h possibly because these cells overexpress p56lck. Although at this time we are uncertain as to the precise role of p56lck in the process of apoptosis, our results indicate that changes in the expression of this protein in thymocytes is an important marker of programmed cell death. J. Leukoc. Biol. 56: 528–532; 1994.
Establishment of the role of IL-6 and TNF receptor 1 using gene knockout mice
Authors: Bluethmann Horst , Rothe Joachim , Schultze Nathalie , Tkachuk Maria , Koebel Pascale
Published: January 2018

Cytokines are known to be key players in host response to infection, immunological disorders, and tissue injury in the attempt of an organism to overcome the insult and restore homeostasis. Another important aspect of cytokines, however, is their normal physiological role during development in the unchallenged organism. The most elegant way to analyze both of these functions is to introduce targeted mutations in embryonic stem cells in order to create new mouse strains deficient for a given cytokine and identify the functions that are consequently impaired or lost, This review summarizes the mutant phenotypes of mice carrying a null mutation in the cytokine IL-6 gene or the tumor necrosis factor receptor 1 (Tnfr1) gene. Results for interferon– and interferon-γ receptor-deficient mice are included for comparison. J. Leukoc. Biol. 56: 565–570; 1994.
Effects of fatty acids on proliferation and activation of human synovial compartment lymphocytes
Authors: DeMarco Deborah M , Santoli Daniela , Zurier Robert B
Published: January 2018

The object of this study was to determine the effects of eicosanoid precursor fatty acids on activation and proliferation of T lymphocytes from synovial fluid and synovial tissue of rheumatoid arthritis patients. Proliferation was determined by direct cell counts; phenotypic characterization of surface molecules was by cytofluorometric analysis. Dihomogammalinolenic acid, arachidonic acid, and eicosapentaenoic acid suppressed proliferation of interleukin-2-dependent lymphocytes by as much as 80%; cell viability was not altered by fatty acids. Administration of particular fatty acids may prove to be a useful therapeutic intervention in rheumatoid arthritis patients because of their ability to suppress activation and proliferation of synovial compartment T lymphocytes. J. Leukoc. Biol. 56: 612–615; 1994.
Delivery of exogenous antigen into the major histocompatibility complex class I and class II pathways by electroporation
Authors: Li Ying , Ke Yong , Gottlieb Paul D , Kapp Judith A
Published: January 2018

Exogenous, nonreplicating protein antigens (Ags) are usually taken up by antigen-presenting cells (APCs) via endocytosis or pinocytosis and enter the major histocompatibility complex (MHC) class II processing and presentation pathway. Although exogenous Ags are not processed and presented in the class I pathway by most cells, soluble proteins can enter the class I processing and presentation pathway if they are introduced directly into the cytoplasm of APCs. The purpose of these studies was to determine whether exogenous proteins could be processed and presented to T cells if they were delivered into cells by electroporation. The conditions for electroporation were optimized so that the viability of the electroporated cells was high, and the majority of electroporated cells had protein incorporated. Electroporated B cells not only presented exogenous ovalbumin to CD8+, class I MHC–restricted T cells but also stimulated CD4+, class II MHC–restricted T cells. Electroporated cells also primed Ag-specific cytotoxic T lymphocytes (CTLs) in vivo, stimulated CTL precursors in vitro, and served as target cells for lysis by Ag-specific CTLs, indistinguishable from transfected cells. Thus, electropermeabilized cells were structurally intact, and the introduced exogenous protein was processed and presented in association with both class I and class II MHC molecules. This approach is as efficient and reproducible as other techniques of delivering exogenous proteins into the intracellular processing pathways. These studies suggest that electroporation could be employed for the study of cell-mediated immunity to various exogenous proteins. J. Leukoc. Biol. 56: 616–624; 1994.
Cellular composition of Corynebacterium pseudotuberculosis pyogranulomas in sheep
Authors: Pépin Michel , Pittet Jean-Christophe , Olivier Michel , Gohin Isabelle
Published: January 2018

The cellular composition of 46 pyogranulomas experimentally induced with Corynebacterium pseudotuberculosis in sheep was determined by immunohistochemistry. Lesions localized in inoculation sites or draining lymph nodes consisted of macrophage and lymphocyte layers distributed around a necrotic center and surrounded by a fibrous capsule. In immature lesions, T cells of the CD4+ subset predominated, whereas in mature lesions proportions of CD8+ T lymphocytes and cells expressing the γ/δ chains for the T cell receptor increased. Numerous pyogranuloma cells expressed the interleukin-2 receptor. In addition to these general characteristics, a large individual variability in the proportions of macrophage and T cell subsets was observed for lesions of the same age, in particular for epithelioid macrophages. This heterogeneity suggests a different cellular pattern in relation to the persistence or the elimination of bacteria by the host. J. Leukoc. Biol. 56: 666–670; 1994.
Lipopolysaccharide and splenic tumoricidal macrophage activation
Authors: Verstovsek Srdan , Zaleskis Gintaras , Maccubbin Darbie L , Mihich Enrico , Ehrke M Jane
Published: January 2018

Splenic macrophage tumoricidal activity was examined and a splenic macrophage tumoricidal assay was established. Initially, mixtures of lipopolysaccharide (LPS) and spleen single cell suspensions (SSCS) were cultured for 1–4 days. Adherent macrophages, washed free of nonadherent cells and LPS, were then examined and were found to lack tumoricidal activity in a standard 18-h 51Cr release assay. However, tumoricidal activity was generated if LPS was added to the SSCS cultures at later time points during the 4-day incubation period; maximal activity was seen when LPS was added on day 3. In parallel, significant changes in macrophage autofluorescence and morphology, but not phenotype, were observed. Next, SSCS were cultured for 1–4 days without stimulating agents. Adherent macrophages were then washed free of nonadherent cells and LPS was added. Significant tumoricidal activity developed in time- and LPS concentration-dependent fashions. The presence of nonadherent spleen cells in physical contact with the macrophages during the SSCS culture was essential for the macrophages in the resultant monolayer to be responsive to LPS. Activated splenic macrophage-mediated lysis of tumor cells was shown to depend on the contact between the two cells. J. Leukoc. Biol. 56: 714–722; 1994.
Cellular target of in vitro–induced suppressor cells derived from the spleen of Mycobacterium lepraemurium–infected mice and role of IFN-γ in their development
Authors: Gosselin Diane , Turcotte Raymond , Lemieux Suzanne
Published: January 2018

Unfractionated spleen cells from C3H mice infected a few weeks before with Mycobacterium lepraemurium developed a suppressor activity after overnight culture. This requires contact of plastic adherent cells with nonadherent cells distinct from T, B, or natural killer cells. The present study demonstrates that anti-interferon-γ (IFN-γ) monoclonal antibody and indomethacin totally abrogate the expression, although not the induction, of this activity. Furthermore, culture-induced suppressor cells selectively inhibit T lymphocyte proliferation, probably by altering the generation of interleukin-2 (IL-2) responsiveness through reduction of the affinity and density of high-affinity IL-2 receptors on activated cells. These and other previously determined properties of culture-induced suppressor cells, similar to those of adherent suppressor cells detected in freshly harvested spleen cells at a later stage of M. lepraemurium infection, suggest a common precursor. If so, the present observations should help in defining a strategy to prevent the impairment of cell-mediated immunity in infected mice. J. Leukoc. Biol. 57: 122–128; 1995.
Polar agents with differentiation inducing capacity potentiate tumor necrosis factor-mediated cytotoxicity in human myeloid cell lines
Authors: Depraetere Stany , Vanhaesebroeck Bart , Fiers Walter , Willems Jean , Joniau Marcel
Published: January 2018

Cotreatment or pretreatment of several human myeloid cell lines (KG1, HL60, U937, THP1) with the differentiation inducer DMSO was found to potentiate the antiproliferative and cytotoxic effects of TNF. In addition, TNF-resistant monocytic cell lines could be sensitized to TNF cytotoxicity by DMSO treatment. Other highly polar molecules, known to be potent differentiation inducers, showed similar effects to those of DMSO. The potentiating effect of DMSO was related neither to an up-regulation of TNF receptor expression nor to an alteration in the rate of TNF internalization and degradation. We present evidence that the TNF activities are p55 TNF receptor-mediated and are not due to insertion of TNF into lipid bilayers, an effect that could be susceptible to DMSO, as this component has been described to modify cell membrane characteristics. DMSO-induced potentiation of TNF cytostasis/cytotoxicity was restricted to myeloid leukemia cell lines. In non-myeloid cells such as fibrosarcomas, myosarcomas, thymomas, or carcinomas, DMSO was found either not to alter or to inhibit TNF-induced cell death. The latter results are in good agreement with data reported by others who suggested that DMSO could act as a scavenger of TNF-induced toxic radical formation. The potential correlation in myeloid cells between DMSO-induced changes in the cells’ differentiation status and DMSO-enhanced TNF-susceptibility is discussed. J. Leukoc. Biol. 57: 141–151; 1995.
Expression of glycophosphatidylinositol-anchored and-non-anchored isoforms of vascular cell adhesion molecule 1 in murine stromal and endothelial cells
Authors: Kinashi Tatsuo , Pierre Yves St , Springer Timothy A
Published: January 2018

Monoclonal antibodies to murine vascular cell adhesion molecule-1 (VCAM-1, CD106) revealed not only the expected VCAM-1 molecule with an apparent molecular weight of 100 kDa, but also a molecule with a smaller size of 46 kDa in stromal cells and stimulated endothelial cells. Peptide mapping suggested the 46 kDa and 100 kDa proteins were closely related. The 46 kDa, but not 100 kDa protein, was cleaved from the cell surface with phosphatidylinositol-specific phospholipase C (PI-PLC), showing that the 46 kDa protein was a GPI-linked molecule. The 46 kDa and 100 kDa isoforms of VCAM-1 were shown to be N-glycosylated, have similar kinetics of biosynthesis, and to be partially shed from the cell surface with a slight reduction of size. TNF-α induced both isoforms of VCAM-1 with a similar time course of appearance on the surface of endothelial cells. The relative amounts of the 46 kDa and 100 kDa isoforms depended on the cell type examined. The GPI-anchored isoform is functionally important, because on a cell on which it was expressed almost as well as the 100 kDa isoform, treatment with PI-PLC reduced VLA-4-dependent conjugate formation. J. Leukoc. Biol. 57: 168–173; 1995.
Time course of coronary vascular endothelial adhesion molecule expression during reperfusion of the ischemic feline myocardium
Authors: Weyrich Andrew S , Buerke Michael , Albertine Kurt H , Lefer Allan M
Published: January 2018

The time course of endothelial P-selectin, ICAM-1, and E-selectin expression was studied in a feline model of myocardial ischemia and reperfusion. Cats were subjected to 90 min of myocardial ischemia followed by 0, 10, 20, 60, 150, or 270 min of reperfusion. At the end of reperfusion, the coronary vasculature was examined immunohistochemically to localize monoclonal antibodies (mAbs) PB1.3, RR1/1, and Cyl787 directed against P-selectin, ICAM-1, and E-selectin, respectively. Immuno-histochemical localization for P-selectin, recognized by mAb PB1.3, was maximally expressed 20 min after reperfusion in 60 ± 6% of coronary venules (P < 0.05 compared to non-reperfused controls), and covered 59 ± 3% of the endothelial cell perimeter of immunostained coronary venules. Immunolocalization of mAb PB1.3 gradually declined at 60, 150, and 270 min of reperfusion. Immunohistochemical localization of mAb RR1/1 (anti-ICAM-1) in endothelial cells of coronary venules was observed to a modest extent in non-ischemic myocardium and at 10, 20, and 60 min of reperfusion, but was significantly increased following 150 and 270 min of reperfusion (P < 0.05 compared non-reperfused controls). At 270 min post-reperfusion, mAb RR1/1 was seen in 50 ± 4% of coronary venules. Endothelial immunolocalization of mAb Cyl787 (anti-E-selectin) was only observed in 13 ± 1 and 14 ± 3% of coronary venules after 150 and 270 min of reperfusion, respectively, suggesting that pronounced expression of E-selectin does not occur within 270 min after reperfusion. These results demonstrate sequential expression of three major endothelial cell adherence molecules in situ following myocardial ischemia and reperfusion. The timing of endothelial cell expressed P-selectin and ICAM-1 could coordinate neutrophil trafficking during the early stages of reperfusion. J. Leukoc. Biol. 57: 45–55; 1995.
In vivo activation of heterophil function in chickens following injection with Salmonella enteritidis-immune lymphokines
Authors: Kogut Michael H , McGruder Edward D , Hargis Billy M , Corner Donald E , DeLoach John R
Published: January 2018

We have previously shown that increased resistance to Salmonella enteritidis organ infectivity in day-old chicks was conferred by the immunoprophylactic administration of S. enteritidis-immunc lymphokines (ILK). This resistance was associated with a significant increase in the number of circulating heterophils 4 h after ILK injection. The objective of the present study was to evaluate heterophil function following the administration of ILK in day-old chicks. Significant increases (P < 0.001) in adherence, chemotaxis, and phagocytosis of S. enteritidis were found with heterophils isolated from ILK-injected chickens compared to the heterophils isolated from birds injected with either pyrogen-free saline or lymphokines from non-immune T cells. After phagocytosis, the heterophils from the ILK-injected chickens were also able to kill significantly greater numbers of S. enteritidis more rapidly than did the heterophils from the saline-injected control birds (within 30 min, control cells killed 21.89% of the bacteria whereas ILK-treated cells killed 88.22%). We also found that the heterophils from the ILK-injected birds were more efficient killers of S. typhimurium, S. gallinarum, and E. coli These results strongly suggest that the protection against S. enteritidis organ invasion induced by the prophylactic treatment of day-old chicks with ILK involves activated heterophils which migrate rapidly to the inflammatory stimulus where they phagocytize and kill the bacteria. J. Leukoc. Biol. 57: 56–62; 1995.
Signal transduction by cell adhesion receptors in leukocytes
Authors: Rosales Carlos , Juliano Rudy L
Published: January 2018

Leukocytes usually pass through the blood stream as nonadherent cells, but during an immune response and inflammation, they become adherent in order to migrate through tissues. Three families of adhesion molecules, the immunoglobulin family, the selectins, and the integrins, participate in interactions between leukocytes and tissues. Near sites of inflammation, leukocytes initially interact with the endothelium via selectins, causing them to slow down and to roll along the walls of blood vessels. Next, chemoattractans induce the activation of integrins on leukocytes. Finally, activated integrins mediate leukocyte migration through the endothelium into the inflamed site. Interactions of leukocytes with other cells and various extracellular matrix (ECM) proteins lead to different functional cell responses, including changes in growth, behavior, and differentiation. Many of these interactions are mediated by integrins, which “integrate” ECM protein signals with the cytoskeleton and which also act as true receptors that generate biochemical signals within the cell. Changes in pH, cytoplasmic Ca2+ concentration, phosphorylation, and gene induction have all been observed after integrin engagement. Adhesion-mediated gene induction in monocytes is perhaps the best example that integrins initiate signaling cascades in the cell to deliver information from the ECM all the way to the nucleus. J. Leukoc. Biol. 57: 189–198: 1995.
Distinct biochemical responses of hepatic macrophages and endothelial cells to platelet-activating factor during endotoxemia
Authors: Gardner Carol R , Laskin Jeffrey D , Laskin Debra L
Published: January 2018

Acute endotoxemia is associated with activation of hepatic macrophages and endothelial cells. These cells release a variety of inflammatory mediators that have been implicated in tissue injury. In the present studies, we analyzed the biochemical responses of these cells to platelet-activating factor (PAF), a lipid autacoid released during hepatic inflammatory responses. To induce acute endotoxemia, rats were injected intravenously with lipopolysaccharide (LPS). Using the calcium sensitive fluorescent indicator dye Indo-1, we found that PAF induced a rapid and transient increase in intracellular calcium in both hepatic macrophages and endothelial cells. Induction of acute endotoxemia resulted in an increase in the amount of calcium mobilized by both cell types. Although endothelial cells from control rats were less responsive to PAF than macrophages, these cells were more sensitive to in vivo endotoxin. PAF was also found to cause a rapid decrease in intracellular pH in hepatic macrophages that was quantified by fluorescence image analysis using the pH sensitive dye SNAFL-calcein. This decrease occurred more rapidly in macrophages from endotoxemic rats. In cells from both control and endotoxemic rats, the effects of PAF on intracellular pH were inhibited by the specific PAF antagonist triazolam. In contrast to hepatic macrophages, PAF had no effect on intracellular pH in endothelial cells from either control or endotoxemic rats. Ligand binding studies demonstrated that both hepatic macrophages and endothelial cells possess high affinity binding sites for PAF. Macrophages expressed 6- to 7-fold more binding sites/cell than endothelial cells and exhibited a higher Kd. Whereas treatment of rats with LPS had no effect on the Kd for PAF binding to macrophages or on the number of binding sites, a significant increase in both of these receptor characteristics was observed in endothelial cells. Taken together, the present data suggest that the biochemical responses of endothelial cells and macrophages to PAF are distinct. Furthermore, cellular activation induced by PAF in endothelial cells appears to be independent of changes in intracellular pH. J. Leukoc. Biol. 57: 269–274; 1995.
Differential effects of anti-inflammatory cytokines (IL-4, IL-10 and IL-13) on tumoricidal and chemotactic properties of human monocytes induced by monocyte chemotactic and activating factor
Authors: Yano Seiji , Sone Saburo , Nishioka Yasuhiko , Mukaida Naofumi , Matsushima Kouji , Ogura Takeshi
Published: January 2018

The effect of recombinant human IL-4, IL-10, and IL-13 on the chemotaxis and antitumor activity of human blood monocytes induced by monocyte chemotactic and activating factor (MCAF) was examined. MCAF alone did not induce monocyte-mediated cytotoxicity against human melanoma (A375-M) cells whereas it significantly enhanced the cytotoxicity by norMDP-stimulated monocytes. MCAF, unlike IFN-γ, had no priming effect on monocyte activation by norMDP. MCAF acted with norMDP or LPS to enhance the production of both IL-1β and TNF-α. Enhanced cytotoxicity of monocytes stimulated with MCAF plus norMDP was reduced by IL-1 receptor antagonist and anti-TNF-α antibody. IL-4, IL-10, and IL-13 suppressed the generation of antitumor activity and cytokine production (IL-1β and TNF-α) of monocytes stimulated with MCAF plus norMDP or LPS. Chemotaxis of monocytes induced by MCAF was not affected by norMDP or any of the anti-inflammatory cytokines (IL-4, IL-10, and IL-13). Moreover, the pretreatment of monocytes with anti-inflammatory cytokines did not suppress monocyte-chemotaxis. These findings suggest that in vivo recruitment and anti-tumor expression of blood monocytes induced by MCAF may be differently regulated by anti-inflammatory cytokines in vivo. J. Leukoc. Biol. 57: 303–309; 1995.
Secreted glucocorticoids regulate leukocyte-endothelial interactions in inflammation. A direct vital microscopic study
Authors: Farsky Sandra P , Sannomiya Paulina , Garcia-Leme J
Published: January 2018

Leukocytes come into intimate contact with the venular endothelium as they extravasate from blood to the interstitium during inflammation. In exteriorized tissues, the number of leukocytes rolling along the vessel wall was markedly increased in adrenalectomized and metyrapone-treated animals, relative to sham-operated and normal animals. During the development of an acute, local inflammatory response, rollers were numerically decreased and a stronger adhesion of the cells to the endothelium, with a concomitant migration into tissues, was observed. Adhesion and migration were much more marked in adrenalectomized and metyrapone-treated animals than in controls, suggesting that secreted glucocorticoids exert a suppressive effect on leukocyte-endothelial interactions. The increased number of rolling leukocytes in adrenalectomized and metyrapone-treated animals apparently resulted in more cells available to migrate into inflamed tissues. The effect appears to involve receptor occupancy and induction of gene expression because normal animals receiving the steroid antagonist RU 38 486, actinomycin D, or cydoheximide behaved as adrenalectomized or metyrapone-treated animals. Administration to adrenalectomized animals of a monoclonal antibody to the membrane glycoprotein complex GD18 did not affect the number of rolling cells, but dramatically reduced the number of adherent or migrated leukocytes. It is suggested that secreted glucocorticoids, in addition to an effect on rolling behavior of circulating leukocytes, might also modulate the activity of the glycoprotein complex CD18 on white blood cells. The ultimate consequence is a restrictive effect on cell emigration in inflammation. J. Leukoc. Biol. 57: 379–386; 1995.
The role of the innate immune response in Th1 cell development following Leishmania major infection
Authors: Scharton-Kersten Tanya , Scott Phillip
Published: January 2018

Infection of mice with the protozoan parasite Leishmania major is an established model with which to study the in vivo development of CD4+ Th cell subsets. Interferon-γ (IFN-γ), produced by natural killer (NK) cells (AsGM1+, CD4-, CD8-, CD3-), regulates CD4+ T cell subset development and early resistance to L. major. Rapid Th1 cell development and resistance to infection occur in mice that develop an NK cell response early after infection (C3H and immunized BALB/c mice), whereas mice that lack an early NK cell response demonstrate delayed Thl cell development and enhanced early disease (C57BL/6) or lack detectable Thl cell development al together and develop a progressive, fatal infection (BALB/c). Analysis of the requirements for NK cell acti vation in C3H mice revealed that the NK cell response is both interleukin-2 (IL-2) and IL-12 dependent. Although delayed IL-12 production in C57BL/6 mice precludes NK cell activation, the eventual development of a Thl re sponse appears to be IL-12 dependent. In contrast, con comitant production of inhibitory factors (IL-4, IL-10, and transforming growth factor β) with IL-12 and IL-2 prevents NK cell activation in BALB/c mice. Together, these observations support a paradigm of in vivo Th1 cell development that involves IL-12-depcndcnt stimulation of IFN-γ production by NK cells. J. Lcukoc. Biol. 57: 515–522; 1995.
A direct signaling pathway through tyrosine kinase activation of SH2 domain-containing transcription factors
Authors: Fu Xin-Yuan
Published: January 2018

Studies on the mechanism of interferoninduced gene expression revealed a direct signaling path way from ccl1 surface receptors to transcription factors. In this pathway, signal transduction is mediated by a new class of transcription factor STAT (signal transducer and activator of transcription). We have shown that STAT fac tors contain Src homology region 2 and 3 domains and arc phosporylated and activated in the cytoplasm by rcccptor associated tyrosine kinases. The activated tran scription factors then translocate to the nucleus, joined by a nuclcar DNA binding factor, to form an active tran scriptional complex. Recent studies have shown that this direct signaling pathway is the key to control of gene ex pression induced by many cytokines and growth factors. J. Leukoc. BioL 57: 529–535; 1995.
Pathways for the processing and presentation of antigens to T cells
Authors: Monaco John J
Published: January 2018

Two pathways exist within vertebrate cells to generate peptides for recognition by T cells. The “en dogenous” pathway provides peptides to MHC class I molecules for presentation to CD8+ T cells. These pep tides are derived from proteins synthesized or residing in the cytoplasm or nucleus, and involves proteasomes and the ubiquitin pathway of protein degradation, as well as a specific peptide transporter (TAP) that allows these pep tides access to the lumen of the endoplasmic reticulum. The exogenous pathway provides peptides to MHC class II molecules for presentation to CD4+ T cells. These pep tides are derived from extracellular antigens taken up by endocytosis and degraded in the endosomal/lysosomal pathway. Peptide loading of MHC class II molecules re quires the presence of a molecule (H-2M in mouse, HLA-DM in humans) that is structurally related to MHC class II molecules, but the mechanistic basis of this require ment is unknown. The class II region of the MHC con tains a cluster of genes encoding proteins involved in an tigen processing, including genes for two proteasome subunits (LMP2 and LMP7), the peptide transporter hetcrodimer (TAPI and TAP2), and the H-2M/HLA-DM molecule (Ma and Mb, or DMA and DMB). J. Lcukoc. Biol. 57: 543–547; 1995.
Effects of granulocyte colony-stimulating factor and interferon-γ on antifungal activity of human polymorphonuclear neutrophils against pseudohyphae of different medically important Candida species
Authors: Roilides Emmanuel , Holmes Andrew , Blake Cassann , Pizzo Philip A , Walsh Thomas J
Published: January 2018

Polymorphonuclear neutrophils (PMNs) are the major host defense against pseudohyphae, the inva sive form of Candida species. We studied the effects of granulocyte colony-stimulating factor (G-CSF) and interfcron-γ (IFN-γ) on the PMN-induced damage of pseudohyphae of Candida albicans, Candida tropicalis, and Candida parapsilosis in vitro by using two antifungal assays: a modified limiting dilution assay and a colorimet ric metabolic 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tctraznlium bromide assay. PMNs from healthy volunteers were ineubated with either G-CSF (100-10,000 U/ml) or IFN-γ (10-5000 U/ml) or buffer at 37° C for 90 min and their capacity to damage nonopsonized pseudohyphae was then measured. C. tropicalis appeared to be the most susceptible species, whereas C. parapsilosis showed the highest rate of rcsistancc to PMN damage. G-CSF (500–10T000 U/ml) and IFN-γ (100-1000 U/ml) enhanced the antifungal activity of PMNs against C. albicans pseudo hyphae (P < .01 and P < .05). Among the others, G-CSF enhanced PMN-induccd damage of C. parapsilosis at concentrations 500–10,000 U/ml (P < .05), whereas it enhanced damage of C, tropicalis only at 10,000 U/ml (P < .01), IFN-γ (100–1000 U/ml) primed PMNs also caused augmented damage of C. parapsilosis (P < .05) but not of C, tropicalis at the same concentrations. Species-dependent differences exist in the responses of PMNs to Candida pseudohyphae and G-CSF as well as IFN-γ are important immunomodulators of phagocytic host defenses against them Leukoc. Biol. 57: 651–656; 1995.
Cytokine regulation of angiogenesis in breast cancer: the role of tumor-associated macrophages
Authors: Lewis C E , Leek R , Harris A , McGee J O’D
Published: January 2018

Studies over the past 20 years have established that the development of new capillaries from an existing vascular network (a process called angiogenesis) is an essential component of tumor growth. Malignant tumors do not grow beyond 2–3 mm3 in size unless they stimulate the formation of new blood vessels and thus provide a route for the increased inflow of nutrients and oxygen and outflow of waste products. Tumor angiogenesis also provides an essential exit route for metastasizing tumor cells from the tumor to the bloodstream. Indeed, extensive neovascularization is a poor prognostic factor in several forms of human cancer. Angiogenesis is a complex, multistep process driven by many local signals within the tumor. This involves the degradation of the extracellular matrix around a local venule after the release of collagenases and proteases, the proliferation and migration of capillary endothelial cells, and their differentiation into functioning capillaries. Cytokines produced by various cell types present within the microenvironment of solid tumors form a complex, dynamic network in which they have multiple effects on tumor progression. Herein we review our work on the presence, and possible regulatory influence on tumor angiogenesis, of a number of these cytokines within invasive breast carcinomas. We have combined immunocyto-chemistry with a single cell cytokine release assay called the reverse hemolytic plaque assay to investigate the cellular sources of the key angiogenic cytokines, vascular endothelial growth factor, basic fibroblast growth factor, and tumor necrosis factor-α. Tumor-associated macrophages in the stromal compartment of these tumors and/or malignant epithelial cells were seen to be a major producer cell for these cytokines, whereas tumor necrosis factor-α receptors were expressed by leukocytes, malignant cells, and endothelial cells in tumor blood vessels. J. Leukoc. Biol 57: 747–751; 1995.
Cell line cross-contamination of U-397
Authors: Reid Yvonne A , O’Neill Kathleen , Chen T R , Dorotinsky Catherine , McGuire Linda , Macy Marv , McCuntock Patrick , Hay Robert
Published: January 2018

To the Editor: The human histiocytic lymphoma cell line, U-937, established by S. Sundström and K. Nilsson in 1974 (1), was deposited at American Type Culture Collection (ATCC) in 1981 by H. Koren, Duke University Medical Center, Durham, N.C. A starter culture obtained from the depositor was propagated through one passage to generate a “token” freeze (F-2704). Progenies from ampules of this cryopreserved material were expanded to produce the “seed” stock (F-2717) and initial distribution stocks. The seed stock is retained to generate new distribution stocks that are provided to scientific investigators. Cultures derived from token, seed, and distribution stocks were tested for microbial and mycoplasma contamination. The cell line species of origin was confirmed by routine isoenzymology and karyology.
Relationship of phospholipase C- and phospholipase D-mediated phospholipid remodeling pathways to respiratory burst activation in human neutrophils stimulated by Candida albicans hyphae
Authors: Meshulam Tova , Billah M Motasim , Eckel Stephen , Griendling Kathy K , Diamond Richard D
Published: January 2018

Neutrophil (PMN) oxidant release, a key component of defenses against disseminated candidiasis, was preceded by oxidant generation after stimulation by Candida albicans hyphae. Opsonized or unopsonized hyphae triggered phospholipase D (PLD) activation within 5 or 30 s, respectively, forming 1-O-alkyl-phosphatidic acid (alkyl-PA) or 1-O-alkyl-phosphatidyl-ethanol in the presence of ethanol. Ethanol, which competitively lowers phosphatidic acid (PA) production, caused dose-dependent inhibition of superoxide (O2-) generation after hyphal stimulation but altered neither baseline-unstimulated O2- production nor responses to phorbol myristate acetate. PA rises evoked by unopsonized hyphae began 2 min before significant O2- release, also preceding both phospholipase C activation and cytosolic Ca2+ rises. Diacylglycerol (DAG) rose in two distinct phases after stimulation by opsonized or unopsonized hyphae, peaking briefly after 60 or 120 s, respectively, followed by prolonged secondary rises. Initial DAG rises preceded inositol triphosphate elevations evoked by unopsonized hyphae. Though PA rose before DAG, no dephosphorylation of PA to form 1-O-alkyl-DAG was noted. Propranalol, which increases PA accumulation by inhibiting PA phosphohydrolase, lowered PMN O2- responses to hyphae. Early DAG rises temporally overlapped respiratory burst initiation but PMN responses to hyphae were unchanged by a DAG kinase inhibitor, R59022, which blocks phosphorylation of DAG to PA and enhances DAG accumulation. Thus, neither PA nor DAG accumulation individually accounted for triggering PMN O2- responses to hyphae. PLD activation and PA production may facilitate PMN fungicidal responses to hyphae but play an indirect role in initiating the respiratory burst. J. Leukoc. Biol. 57: 842–850; 1995.
Human eosinophils in culture undergo a striking and rapid shrinkage during apoptosis. Role of K+ channels
Authors: Beauvais Francis , Michel Laurence , Dubertret Louis
Published: January 2018

In the absence of appropriate stimulus, eosinophils in vitro rapidly exhibit the features of apoptotic cells (nuclear pycnosis, cell shrinkage, DNA fragmentation). By using electronic cell sizing, we precisely measured the volume distribution of human eosinophils during apoptosis. We observed that apoptosis of eosinophils was accompanied by a marked cell volume decrease (approximately 60%). Moreover, analysis of the volume distribution in different experimental conditions (kinetics of apoptosis, inhibition of apoptosis by cytokines) revealed that the cell shrinkage, once triggered, was a fast process in which the intermediate states between normal and shrunken volume had a short half-life. As a model of apoptosis, the eosinophil model allowed us to test the hypothesis that apoptotic cell shrinkage was linked to osmotic changes due to leakage of internal ions. Indeed, in the presence of K+ channel blockers, the shrinkage was inhibited in a dose-dependent manner. In conclusion, our results suggest that eosinophil shrinkage during apoptosis is a striking and rapid phenomenon and osmotic changes due to K+ efflux could be responsible, at least in part, of the volume decrease. J. Leukoc. Biol. 57: 851–855; 1995.
Lipopolysaccharide-inactivating activity of neutrophils is due to lactoferrin
Authors: Wang Demin , Pabst Karen M , Aida Yoshitomi , Pabst Michael J
Published: January 2018

Neutrophils can inactivate lipopolysaccharide (LPS), thereby blocking the ability of LPS to prime fresh neutrophils for enhanced fMLP-triggered release of superoxide. Here we show that inactivation of LPS by neutrophils was primarily due to lactoferrin. A time course for inactivating LPS showed that neutrophils (5 million/ml) took 30 min to inactivate 10 ng/ml LPS. Mononuclear cells could not inactivate LPS under the same conditions. Experiments with radioactive LPS showed that inactivated LPS remained in the medium and was not taken up or destroyed by the neutrophils during inactivation. Inactivated IPS still gelled Limulus lysate and primed monocytes. Cell-free medium from neutrophil suspensions also inactivated LPS. A single LPS-inactivating factor was purified from medium by heparin-agarose chromatography. SDS-PAGE showed a single band at 80 kDa, which was identified as lactoferrin by immunoblotting. Antilactoferrin immunoglobulin G removed the LPS-inactivating activity from purified lactoferrin and cell-free medium. Surprisingly, even purified neutrophil lactoferrin required 30 min to inactivate LPS, indicating inherently slow binding of lactoferrin to LPS J. Leukoc. Biol. 57: 865–874; 1995.
Dual function of human IgA antibodies: inhibition of phagocytosis in circulating neutrophils and enhancement of responses in IL-8-stimulated cells
Authors: Nikolova Elena B , Russell Michael W
Published: January 2018

We have sought to elucidate the responses of human peripheral blood neutrophils to antigenic surfaces complexed with human specific IgA antibodies obtained either as myeloma proteins that recognize staphylococcal α-toxin, or from the serum of patients with subacute bacterial endocarditis due to Streptococcus mutans, or from colostrum. In contrast to IgG, IgA antibodies bound to antigen-coated fluorescent microspheres, and subsequently exposed to complement (or not), did not promote phagocytosis, as measured by flow cytometric enumeration of cell-associated microspheres. Instead, IgA antibodies interfered with complement-dependent phagocytosis mediated by IgG antibodies. These properties were shown by different forms of IgA antibodies, including serum and secretory IgA, as well as by monoclonal or polyclonal antibodies. Neutrophils did not respond to the production of superoxide to IgA antibodies complexed with antigen-coated microspheres or with antigen deposited on a solid surface and IgA antibodies suppressed IgG antibody- and complement-mediated superoxide release. However, neutrophils pretreated with interleukin-8 ingested IgA-opsonized microspheres and released superoxide when exposed to IgA antibody-antigen complexes. IgG antibody-antigen complexes did not stimulate increased superoxide release in interleukin-8-treated neutrophils. These findings were consistent with a selective increase in the surface expression of FcoαR by interleukin-8-treated neutrophils. We conclude that IgA antibodies interfere with the phagocytic activities of normal circulating human neutrophils and may promote these activities in inflammatory neutrophils activated by interleukin-8 in which FcαR is up-regulated. J. Leukoc. Biol. 57: 875–882; 1995.
Processing of complex antigens and simple hapten-like molecules by epidermal Langerhans cells
Authors: Woods Gregory M , Henderson Kirsten G , Qu Miaomiao , Muller H Konrad
Published: January 2018

Langerhans cells (LCs) are antigen-presenting cells of the skin that trap small contact-sensitizing molecules and induce cutaneous hypersensitivity. LCs can present larger molecules but the mechanisms of processing have required investigation. A system combining in vitro culture of antigen with epidermal cells in the presence of inhibitors, followed by fixation and transfer of these antigen/drug-treated epidermal cells to naive mice, was developed to investigate the steps of antigen processing. Langerhans cells undertake similar, but not identical, pathways for the processing of simple and complex molecules. Complex molecules such as trinitrophenyl conjugated to ovalbumin (TNP-OVA) were internalized and modification required a chloroquine-sensitive proteolysis step and a cycloheximide-sensitive protein synthesis step. This modified product was actively recycled to the cell membrane as presentation was inhibited by blocking receptor translocation with either monensin or cytochalasin B. Small contact sensitizers such as trinitrophenyl did not undergo modification but required internalization and presentation was also inhibited by blocking receptor translocation. J. Leukoc. Biol. 57: 891–896; 1995.
Negative regulators may mediate some of the inhibitory effects of HIV-1 infected stromal cell layers on erythropoiesis and myelopoiesis in human bone marrow long term cultures
Authors: Schwartz G N , Kessler S W , Szabo J M , Burrell L M , Francisš M L
Published: January 2018

This report presents results concerning the potential role of negative regulators in hematopoietic suppression observed in human immunodeficiency virus (HIV)-infected long-term cultures (LTC) of human bone marrow cells. Confluent stromal cell layers established from human bone marrow cells were exposed to HIV-1ADA, a monocytotropic strain of HIV-1. A progressive increase in the concentration of HIV-1 p24 antigen in cultures exposed to HIV-1ADA demonstrated that there was a productive infection. Cells from both noninfected and HIV-infected stromal cell layers produced factors that stimulated the proliferation of colony-forming units for granulocytes and macrophages (CFU-GM) from noninfected CD34+ cells. In contrast, when noninfected CD34+ cells were directly cocultured on intact stromal cell layers fewer CFU-GM and burst-forming units for erythroid cells (BFU-E) were detected in HIV-infected LTC than in noninfected LTC. One week after the addition of CD34+ cells, the number of CFU-GM in HTV-infected LTC in six of nine experiments was reduced compared to noninfected control LTC. In those six experiments, the number of CFU-GM was only 53 ± 5% (SEM) of the number in noninfected LTC. The number of BFU-E in HIV-1-infected LTC was only 46 ± 5% of the number in noninfected LTC (n = 5). There were fewer BFU-E in HIV-1-infected LTC, whether or not there was a reduced number of CFU-GM. Neutralizing antibody to tumor necrosis factor α (TNF-α) had no effect on the number of BFU-E in HIV-infected LTC. The number of BFU-E, however, was 2.1 ± 0.2-fold greater (n = 3) in HIV-infected LTC incubated with neutralizing antibody to interferon-α. In HIV-infected LTC with decreased numbers of CFU-GM, the number of CFU-GM was approximately 2-fold greater after incubation of HIV-infected LTC with anti–interleukin-4 (IL-4). The effect of anti–TNF-α was variable, and anti–transforming growth factor-β had no effect on the number of CFU-GM in HIV-infected LTC. After 2 weeks, the number of CFU-GM in HIV-infected LTC incubated with anti–IL-4 and anti–TNF-α was 2- to 4-fold greater than in untreated HIV-infected LTC. Antibody treatment did not promote an increase in the number of CFU-GM in noninfected LTC or in LTC in which CFU-GM numbers were not reduced after HIV infection. These results demonstrate that some cells in the stromal cell layers of LTC were targets for HTV-1ADA, and that HIV-infected stromal cell layers suppressed or delayed the production of both CFU-GM and BFU-E. These results also suggest that hematopoietic suppression in HIV-infected LTC may be mediated by growth-inhibitory cytokines that are different for erythropoiesis and myelopoiesis. J. Leukoc. Biol. 57: 948–955; 1995.
CD82, tetra-span-transmembrane protein, is a regulated transducing molecule on U937 monocytic cell line
Authors: Lebel-Binay Sophie , Lagaudrière Cécile , Fradelizi Didier , Conjeaud Hélène
Published: January 2018

The mononuclear cell surface protein IA4, recently classified as CD82, was originally identified in our laboratory by the IA4 monoclonal antibody (mAb), because of its high expression on three lymphoblastoid, LAK-susceptible, variant cell lines. We have characterized CD82 as a new activation/differentiation marker of mononuclear cells. This protein belongs to the new family of TST proteins (tetra spans transmembrane), which includes CD9, CD37, CD53, CD63, and CD81 (TAPA-1). Here we demonstrate that cross-linking of IA4 mAbs induces an increase of intracellular free calcium in U937 cells and tyrosine phosphorylation of various proteins. Our data indicate that the intracellular calcium increase is initiated by a phospholipase C (PLC)–induced PtdIns(l,4,5)P3 second messenger followed by a more stable change, linked to extracellular calcium entry. This transducing signal was dependent on dual engagement of both CD82 and Fc receptors. Surface cross-linking of CD82 together with Fc receptors (FcRs) induces a specific long-lasting increase of intracellular calcium, whereas FcR cross-linking alone induces only a transient calcium mobilization. These results suggest that, upon cross-linking of CD82, a multimolecular complex including CD82 and FcR could be induced that is able to trigger signal transduction. We have previously shown that CD82 membrane expression is up-regulated during differentiation of human monocytes. Using U937 cells, we demonstrate here that several cytokines [interleukin-1β (IL-lβ), IL-4, IL-6, IL-13, interferon-γ, tumor necrosis factor α] could significantly up-regulate the surface expression of CD82 antigen, by contrast with FcR surface expression, which was up-regulated only after IFN-γ treatments. Based on our finding of a strict dependence of CD82 activation on FcR stimulation, we suggest a putative role of CD82 in enhancing FcR-mediated activation of cells from the monocyte/macrophage lineage. J. Leukoc. Biol. 57: 956–963; 1995.
Modulation of human G-CSF receptor mRNA and protein in normal and leukemic myeloid cells by G-CSF and retinoic acid
Authors: Tkatch Lisa S , Rubin Kristin A , Ziegler Steven F , Tweardy David J
Published: January 2018

Granulocyte colony-stimulating factor (G-CSF) is produced by several cell types throughout the body and has a variety of effects on neutrophils and their precursors, which are mediated by binding to its receptor. It is not yet known what physiologic factors modulate G-CSF receptor mRNA expression in these cells. We studied the effect of G-CSF on freshly isolated neutrophils and bone marrow cells from normal human subjects and on myeloid leukemic cell lines. We found that G-CSF receptor mRNA levels were maintained by G-CSF in neutrophils but not in bone marrow cells. Of the leukemic cell lines tested, K562 and BV173, both of which contain the bcr-abl translocation, neither expressed G-CSF receptor mRNA. Whereas G-CSF did not affect mRNA levels for its receptor in myeloid leukemic cell lines, exposure of the acute promyelocytic cell line, NB4, to all-trans retinoic acid induced a striking increase in G-CSF receptor mRNA expression and resulted in increased G-CSF receptor surface expression. The effect of retinoic acid on G-CSF receptor mRNA on NB4 cells occurred early, before morphologic evidence of differentiation, and required protein synthesis. All-trans retinoic acid also up-regulated G-CSF receptor mRNA in the myeloid leukemia cell line HL-60. Thus, maintenance of G-CSF receptor on neutrophils by G-CSF may extend the duration of ligand responsiveness. Furthermore, the ability of retinoic acid to up-regulate G-CSF receptor may account for the synergistic effect of G-CSF and retinoic acid in differentiation induction of acute promyelocytic leukemia. J. Leukoc. Biol. 57: 964–971; 1995.