bluuebunny/crossref_metadata_2025 huggingface dataset:
Granule Changes of Human Skin Mast Cells Characteristic of Piecemeal Degranulation and Associated With Recovery During Wound Healing In Situ
Authors: Dvorak Ann M , Kissell Susan
Published: January 2018

Human skin mast cells (HSMC) in situ were examined by electron microscopy of surgical biopsy specimens obtained from a wide variety of circumstances. From these studies, it is apparent that the general ultrastructural morphology of normal HSMC is similar to that of human mast cells from other sites, except that the most prevalent granule pattern is that of crystal granules. Scroll granules, particle granules, and mixed granules can also occur in HSMC. Cytoplasmic lipid bodies occur in HSMC extremely rarely, unlike mast cells from lung and gut. Circumstances in which piecemeal degranulation (PMD) of HSMC occurs, such as bullous pemphigoid, examined at high magnifications, revealed typical, focal geographic losses from cytoplasmic granules, often leaving completely empty granule containers in the cytoplasm. Crystal portions of mixed granules were uniquely susceptible to granule losses typified by PMD. Cytoplasmic smooth vesicles were prominent in PMD. These structures were either empty or contained granule-like dense materials and were free in the cytoplasm or attached to granules. HSMC present in wound healing revealed recovery from PMD losses. Typically these granules contained numerous irregular foci of markedly dense new granule products within empty or partially empty granule containers. The morphology of PMD and recovery of HSMC in vivo is contrasted with the morphology of anaphylactic degranulation (AND) and recovery of human mast cells ex vivo.
Effect of Soluble Aminated β-1,3-D-Polyglucose on Human Monocytes: Stimulation of Cytokine and Prostaglandin E2 Production but Not Antigen-Presenting Function
Authors: Doita Minoru , Rasmussen Lill-Tove , Seljelid Rolf , Lipsky Peter E
Published: January 2018

Glucans are insoluble polymers of β-1,3-linked glucose derived from yeast cell walls that effectively activate macrophages. Recently, aminated derivatives of β-1,3-D-polyglucose have been developed that are soluble but also activate murine macrophages. The current studies were undertaken to determine whether soluble aminated β-1,3-D-polyglucose (AG) would also stimulate human monocytes. The AG employed contained <2 ng endotoxin/mg. AG induced the production of intracellular, membrane-associated, and secreted forms of interleukin 1 (IL1) in a dose-dependent manner, with 50 µg/ml yielding maximal responses. AG also induced tumor necrosis factor-α (TNFα) secretion by human monocytes. Prostaglandin E2 (PGE2) production was also stimulated in a concentration-dependent manner. Quantitatively, optimal stimulatory concentrations of AG were comparable to endotoxin in the capacity to induce production of these various mediators. In contrast to its capacity to induce production of IL1, TNFα, and PGE2, AG did not stimulate monocytes to become more effective antigen presenting cells. These results indicate that AG is a potent inducer of proinflammatory mediators from human monocytes but does not enhance their capacity to initiate immune responses.
Role of Natural Killer Cells in Resistance to Systemic Cryptococcosis
Authors: Salkowski Cindy A , Balish Edward
Published: January 2018

These studies demonstrate that Cryptococccus neoformans infection induced a dose-dependent augmentation of splenic natural killer (NK) cell activity by bg/+, but not bg/bg mice. To directly assess the role of NK cells in resistance to C. neoformans, bg/+ and bg/bg mice were treated with anti-NK-1.1 monoclonal antibody (mAb). Anti-NK-1.1-treatment abrogated the augmented NK cell activity observed during C. neoformans infection in bg/+ mice. Anti-NK-1.1-treated bg/+ mice had higher C. neoformans colony forming units (CFU) in their lungs on days 3 and 7 after intravenous (i.v.) challenge than control bg/+ mice. Moreover, the number of C. neoformans CFU in the lungs of anti-NK-1.1-treated bg/+ mice on days 3 and 7 were similar to those observed for infected bg/bg mice. By day 14, however, no differences in C. neoformans CFU were evident in the lungs of anti-NK-1.1-treated and control bg/+ mice. Anti-NK-1.1-treatment did not alter either the growth of C. neoformans in the spleens, livers, kidneys, or brain of bg/+ mice or the susceptibility of bg/bg mice to systemic cryptococcosis. These studies suggest that NK cells do not play a role in resistance to systemic cryptococcosis in the spleen, but do appear to play an early, but transient role in resistance to C. neoformans in the lungs. Overall, congenital defects in polymorphonuclear neutrophils (PMNs) and macrophages (Mφs), in addition to defects in NK cells, contribute to the enhanced susceptibility of bg/bg mice to systemic cryptococcosis.
Independence of the Pattern of Early Cytokine Release From Autoregulation by Nitric Oxide
Authors: Tucker Stanley D , Sivaramakrishnan Mathoor R , Klostergaard Jim , Lopez-Berestein Gabriel
Published: January 2018

The L-arginine-dependent tumor cell cytotoxicity produced by activated macrophages (Mφ) may be mediated either directly by production of nitric oxide (NO), or by induction of NO synthesis in the tumor cell. The influence of Mφ NO synthesis on the release of soluble cytotoxic mediators was investigated in this study. The synthesis of Mφ NO, measured as nitrite, was detected 6 h after lipopolysaccharide (LPS)-triggering and reached a peak level by 44 h. A concurrent decrease in Mφ viability beginning at 18 h after triggering was detected during a period of 72 h in culture. Both the production of NO and loss of viability correlated with the presence of L-arginine in the incubation media and was inhibited by NG-monomethyl-L-arginine (NMA). The medium in which LPS-triggered adherent peritoneal exudate cells were incubated was examined for the presence of tumor necrosis factor (TNF), gamma interferon (IFN-γ), and the soluble mediators that induce mitochondrial respiratory inhibition in tumor cells. All of these effector molecules were released at peak levels into the conditioned supernatants within 12 h after LPS-triggering. The peak level obtained for each effector molecule was influenced by the media in which the Mφ was incubated; however, no correlation was detected between the level of cytokines produced and the synthesis of nitrite by the Mφ indicating that NO synthesis has no inhibiting effect on the initial burst of cytotoxic factors released.
Characterization of immunosuppressive functions of murine peritoneal macrophages induced with various agents
Authors: Tomioka Haruaki , Saito Hajime
Published: January 2018

Murine peritoneal macrophages (Møs), induced with stimuli such as thioglycollate, zymosan A, OK-432, bacille Calmette-Guérin (BCG), or live Mycobacterium intracellulare, showed varying levels of inhibitory activity against the concanavalin A (Con A) blastogenic response of splenic T cells. All test Møs significantly inhibited the interleukin 2 (IL-2)–producing ability of T cells but this inhibition was not enough to explain the observed reduction in T cell Con A mitogenesis. In contrast, they markedly inhibited IL-2–reactive T cell generation, and the inhibition was sufficient to cause the reduction in T cell mitogenesis. A general relationship was observed between immunosuppressive activity of a given Mø and its active oxygen-producing ability (measured in terms of chemiluminescence) in response to phorbol myristate acetate triggering (r = .84, P < .005). However, the suppressor activity of test Møs was not reduced by superoxide dismutase and catalase, indicating that active oxygen radicals themselves did not mediate the expression of the immunosuppressive activity of these Møs. On the other hand, indomethacin (an inhibitor of prostaglandin synthesis) caused a partial reduction in their immunosuppressive activity. The suppressor activity of Møs induced with intraperitoneal injection of recombinant interferon γ (IFN-γ) was markedly reduced in the presence of myoglobin, a scavenger for nitric oxide radical (NO·). Tumor necrosis factor α (TNF α) failed to affect Con A mitogenesis of splenic T cells, even in combination with IFN-γ. On the other hand, unsaturated long-chain fatty acids including oleic, linoleic, linolenic, and arachidonic acids markedly reduced the T cell function. These findings suggest some important roles of prostaglandins, NO·, and long-chain unsaturated fatty acids as mediators of the expression of immunosuppressive function of the peritoneal Møs.
Metabolism of platelet-activating factor in neutrophils isolated from Pichinde virus–infected guinea pigs
Authors: Qian Changgeng , Liu Ching-Tong , Peters Clarence J
Published: January 2018

Metabolism of platelet-activating factor (PAF) was studied in cultured polymorphonuclear neutrophils (PMNs) obtained from Pichinde virus–infected strain 13 guinea pigs. Neutrophils obtained from control and infected guinea pigs on postinoculation days 10 and 14 were incubated with [3H]lyso-PAF, [3H]PAF, or [3H]acetate. After incubation for 1 h at 37°C, formation of [3H]acyl-PAF from either [3H]lyso-PAF or [3H]PAF increased significantly in PMNs from infected guinea pigs compared to control PMNs. Furthermore, total radioactivity from [3H]lyso-PAF or [3H]PAF was higher in PMNs from infected animals than in those from controls. However, compared to PAF production by control PMNs, production of PAF by infected PMNs was unchanged. These results suggest that PMNs may not be the major source of increased blood PAF levels during Pichinde viral disease.
Differential effects of CD4+ and CD8+ cells in acute, systemic murine candidosis
Authors: Coker Lee A , Mercadal Carmen M , Rouse Barry T , Moore Robert N
Published: January 2018

Monoclonal antibody (mAb) depletion was used to assess contributions of CD4+ and CD8+ cells in resistance to systemic murine Candida albicans infection. Depletion of CD8+ cells did not influence either survival or mean survival time (MST); however, depletion of CD4+ cells significantly enhanced both survival and MST. Combined depletion of both CD4+ and CD8+ cells significantly lengthened the MST but did not enhance survival. A protective influence of CD8+ cells could be deduced but, to be manifested, required depletion of an overshadowing immunopathologic CD4+ response.
In vitro modulation of the toxicity associated with the use of zidovudine on normal murine, human, and murine retrovirus-infected hematopoietic progenitor stem cells with basic fibroblast growth factor and synergistic activity with interleukin-1
Authors: Gallicchio Vincent S , Hughes Nedda K , Hulette Ben C
Published: January 2018

The antiviral drug used in the treatment of acquired immunodeficiency syndrome, zidovudine, has proved effective in ameliorating the morbidity and mortality associated with human immunodeficiency virus infection. However, associated with zidovudine is the development of severe bone marrow toxicity manifested by anemia, neutropenia, and occasionally thrombocytopenia. We report the results of studies that demonstrate the ability of basic fibroblast growth factor (B-FGF) to reduce zidovudine toxicity to several classes of hematopoietic progenitors (granulocyte-macrophage, CFU-GM; megakaryocyte. CFU-Meg; and erythroid, BFU-E) from normal murine, human, and murine retrovirus–infected bone marrow cells when cocultured with zidovudine in vitro. Optimal response to B-FGF was observed at a dose concentration of 10 ng/ml. The specificity of B-FGF was demonstrated in the presence of protamine sulfate, an effective inhibitor of B-FGF mitogenic activity. In addition, synergistic activity of B-FGF on zidovudine-induced hematopoietic stem cell toxicity was observed in the presence of interleukin 1 (IL-1) (30 ng/ml). These studies demonstrate that B-FGF is capable of reducing the hematopoietic toxicity associated with zidovudine and that such an effect can be amplified in the presence of IL-1.
Stimulation of human monocyte and polymorphonuclear cell iodination and interleukin-1 production by epigallocatechin gallate
Authors: Sakagami Hiroshi , Asano Kazuhito , Hara Yukihiko , Shimamura Tadakatsu
Published: January 2018

(-)Epigallocatechin gallate (EGCg) stimulated iodination of human peripheral blood monocytes, polymorphonuclear cells (PMN), and human promyelocytic leukemic HL-60 cells, dependent on time, dose, and temperature. However, EGCg did not affect iodination of nonadherent peripheral blood mononuclear cells, red blood cells, or 11 other cultured cell lines. Although various immunoregulators such as lipopolysaccharide (LPS), opsonized zymosan, 12-O-tetradecanoylphorbol-13-acetate (TPA) and tumor necrosis factor stimulated PMN iodination to varying degrees, their ability to stimulate monocyte iodination was much lower than that of EGCg. Washout experiments demonstrated that contact with EGCg for < 60 min irreversibly stimulated PMN and monocyte iodination. EGCg also potently stimulated the production of interleukin-1-like factor by monocytes. The data suggest that EGCg is a strong in vitro stimulant of human phagocytes.
Platelet activating factor stimulates intracellular calcium transients in human neutrophils: involvement of endogenous 5-lipoxygenase products
Authors: Rediske John J , Quintavalla Joe C , Haston William O , Morrissey Michael M , Seligman Bruce
Published: January 2018

Stimulation of human neutrophils with platelet activating factor (PAF) resulted in a transient elevation of free cytosolic calcium. Neutrophils exhibited a two-component calcium response observed as a double peak when stimulated with > 5 nM PAF. In contrast, leukotriene B4 (LTB4), C5a, or formylmethionyl-leucyl-phenylalanine stimulated only a single-peak calcium response. The double-peak calcium response was not elicited in human monocytes or differentiated U937 cells, which demonstrated a single peak. Pretreatment of neutrophils with a 5-lipoxygenase inhibitor or a specific LTB4-receptor antagonist selectively blocked the second calcium peak. These results suggest that PAF-mediated activation of human neutrophils results in the activation of the 5-lipoxygenase and the subsequent generation of LTB4. This LTB4 in turn elicits a secondary rise in calcium, which contributes to the overall response of neutrophils to PAF. These results demonstrate how LTB4 participates in the cellular responses elicited by PAF in human neutrophils.
Differentiation-dependent modulation of TNF production by PAF in human HL-60 myeloid leukemia cells
Authors: Rola-Pleszczynski Marek , Stankova Jana
Published: January 2018

Platelet-activating factor (PAF) can augment tumor necrosis factor (TNF) production by human monocytes in a bimodal manner, with two peaks of activation at picomolar and micromolar concentrations. These peaks are partially associated with monocyte subsets presenting different characteristics in terms of size, density, phenotypic markers, and [Ca2+]i mobilization responses. In the present study, we used the human promyelocytic leukemia cell line HL-60, at various times during differentiation with 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] toward the monocyte lineage, in order to study the relation of cell differentiation to responsiveness to PAF in terms of cytokine production. TNF production was induced by pretreatment with interferon γ for 24 h and treatment with muramyl dipeptide. Although detectable TNF was produced by 4 day-differentiated cells, no effect was seen with PAF (10−16-10−6 M) at this or earlier stages. In contrast, 5 day–differentiated cells had a comparable baseline production of TNF but responded with a 2.5-fold increase to PAF with a single peak, maximal at 10−8 M. Moreover, 6 day- or 7 day-differentiated HL-60 cells showed a further increase in TNF production in response to PAF, and the response was bimodal, similar to that of the less dense subset of monocytes, with peaks at 10−14 and 10−7 M PAF. In parallel, undifferentiated HL-60 failed to respond to PAF in terms of [Ca2+]i mobilization. The earliest responsiveness to PAF (10−7 M) was observed by 4 days of treatment with 1,25(OH)2D3, and by day 7 the response to PAF became bimodal (10−14 and 10−7 M). These results indicate that myeloid cells acquire, during maturation toward the monocyte lineage, a progressive responsiveness to PAF in terms of [Ca2+]i mobilization and enhanced cytokine production, and they suggest that the heterogeneity in responses to PAF observed in normal monocytes may be related to their stage of differentiation or maturation.
Fucose-activated killer cells. I. Enhanced TNF-α mRNA accumulation and protein production
Authors: Staňková Jana
Published: January 2018

Our previous studies have shown that the monosaccharide α-l-fucose significantly enhances the cytolytic capacity of peripheral blood mononuclear leukocytes (PBMLs). To examine possible mechanisms through which fucose affects cytolytic activity, we studied the production of cytokines after α-l-fucose stimulation. In this report, we show that fucose induced a minor but significant augmentation of production of interleukin-2 (IL-2), but anti–IL-2 antibodies did not completely inhibit fucose-activated cytolysis. Fucose induced significantly higher secretion of TNF-α by both lymphocytes and monocytes. The nature of the lytic molecule detected in the TNF bioassay was verified with specific neutralizing antibodies. In addition, fucose induced the accumulation of TNF-α mRNA in a time-dependent manner with a peak at 8 h and a return to baseline values at 20 h after stimulation. In vitro nuclear transcription assays determined that fucose augmented the rate of transcription of the TNF-α gene, and inhibition of de novo transcription with actinomycin D indicated that the turnover rate of the TNF-α mRNA was not affected by fucose stimulation. We also determined that fucose did not modulate the mRNA expression of the pore-forming protein, a major lytic protein involved in lymphocyte cytotoxicity. Specific neutralizing antibodies indicated that TNF-α was not an effector molecule in fucose-activated killing of K562 or Raji target cells but that this cytokine had an essential role in the induction of the augmented killing by α-l-fucose.
Macrophage inflammatory proteins MIP-1 and MIP-2 are involved in T cell–mediated neutrophil recruitment
Authors: Appelberg Rui
Published: January 2018

Mice intraperitoneally (i.p.) infected with Mycobacterium bovis bacille Calmette-Guérin (BCG) respond to an i.p. challenge with mycobacterial antigen with an acute and extensive accumulation of neutrophils. This influx was not mimicked by the inoculation of recombinant interferon-γ (IFN-γ) or tumor necrosis factor α (TNF-α). The antigen-induced recruitment of neutrophils was not affected by coinoculation of anti–IFN-γ antibodies, was enhanced by anti–TNF-α antisera, and was significantly reduced by antisera against macrophage inflammatory proteins MIP-1 and MIP-2. The latter two sera had no additive effects. We hypothesize that mycobacteria-specific T cells are triggered by antigen to secrete MIP-1 and MIP-2, which directly mediate, at least partly, the influx of neutrophils that takes place in this model.
Polyamine involvement in functional activation of human macrophages
Authors: Messina Luigi , Spampanato Giuseppina , Arcidiacono Antonio , Maiaguarnera Lucia , Pagano Maria , Kaminska Bozena , Kaczmarek Leszek , Messina Angelo
Published: January 2018

Polyamines naturally occur in all living beings and play an important role in the regulation of cell proliferation, differentiation, and functional stimulation of terminally differentiated cells. Our studies, using specific inhibitors of polyamine biosynthesis such as α-difluoro- methylornithine and methylglyoxal-bis[guanylhydrazone] to prevent polyamine accumulation, have indicated that polyamines are associated with functional activation of human macrophages. Both inhibitors diminished the respiratory burst activity of macrophages induced by lipopolysaccharide and interferon gamma. The methyl- glyoxal-bis[guanylhydrazone] inhibitory effect was concentration-dependent and could be reversed by spermine, which is the final product of polyamine biosynthesis.
Syn-capping of human T lymphocyte adhesion/activation molecules and their redistribution during interaction with endothelial cells
Authors: Rosenman Stephen J , Ganji Amir A , Tedder Thomas F , Gallatin W Michael
Published: January 2018

Lymphocyte-endothelial cell interactions are mediated in part by multiple lymphocyte surface adhesion/activation molecules and their cognate ligands. We investigated the surface localization of several of these molecules implicated in T cell adhesion and transen- dothelial migration mechanisms to determine if spatial regulation of their distribution contributes to these processes. T lymphocyte suspensions were stained to define distribution, ability to be aggregated into energy- dependent caps, and potential cocapping of several adhesion structures. CD2, CD44, L-selectin (LAM-1, LECCAM-1), and CDlla/CD18 (LFA-1) exhibited uniform distribution on the T cell surface by direct immunofluorescence but formed caps in an energy- dependent, and therefore cytoskeletally driven, manner when examined by indirect immunofluorescence. CD2 was shown to syn-cap (unidirectionally cocap) with GD44 and CDlla/CD18 (LFA-1), an observation potentially related to functional cooperation among these molecules in T cell activation. T cells were also added to endothelial cell monolayers to assess, in a physiologically relevant context, potential surface molecule reorganization. Lymphocytes co-cultured with human umbilical vein endothelial cells (HUVEC) underwent a profound shape change, from essentially round cells to polarized cells bearing pseudopodia. Immunofluorescent localization of T cell adhesion/activation molecules using confocal microscopy revealed the redistribution of CD2, CD44, and L-selectin to the pseudopod. In contrast, CDlla/CD18 remained globally distributed on the cell surface, even in severely deformed cells. Both lymphocyte shape change and membrane molecule redistribution appear to be cell-cell contact-dependent phenomena requiring intact, viable endothelial cells. Mechanisms that control these events may be critical to lymphocyte recirculation and inflammation. J. Leukoc. Biol. 53: 1–10; 1993.
Immunotherapy of tularemia: characterization of a monoclonal antibody reactive with Francisella tularensis
Authors: Narayanan RB , Drabick Joseph J , Williams Jim C , Fortier Anne H , Meltzer Monte S , Sadoff Jerald C , Bolt Christopher R , Nacy Carol A
Published: January 2018

An IgM monoclonal antibody (mAb) recognized surface antigens specific to Francisella tularensis wild-type (Schu4) and live vaccine strain (LVS), and reacted with both in ELISA and slide agglutination tests. This mAb also reacted with LVS microorganisms in tissues of infected mice as assessed by an indirect fluorescence technique. Western blot analysis showed the mAb to react with antigens associated with F. tularensis LPS. J. Leukoc. Biol. 53: 112–116; 1993.
Effects of modulators of cytosolic Ca2+ on phytohemagglutin-dependent Ca2+ response and interleukin-2 production in Jurkat cells
Authors: Dupuis Gilles , Aoudjit Fawzi , Ricard Isabelle , Payet Marcel D
Published: January 2018

We have previously reported the presence, in Jurkat T cells, of outward K+ currents and inward currents that have been attributed to Ca2+ channels. Here, we have studied the effects of dimethyl 1,4-dihydro- 2,6-dimethyl-4-(2-nitrophenyl)-3,5-pyridine-dicarboxylate (nifedipine) and 4-(2,l,3-benzoxadiazol-4-yl)-l,4-dihydro- 2,6-dimethyl-5-methoxy-carbonylpyridine-3-carboxylate (PN200-110), two dihydropyridines (DHPs) known to inhibit voltage-dependent Ca2+ channel activity in different types of cells, and two inhibitors of internal Ca2+ release (muscle cells), ryanodine and 3,4,5-trimethoxybenzoic acid 8-(diethylamino)octyl ester (TMB-8), on the Phaseo- lus vulgaris phytohemagglutinin (PHA)-dependent responses in Jurkat T lymphocytes. Our results show that nifedipine and PN200-110 inhibit the PHA-dependent production of interleukin-2 except when 12-0- tetradecanoyl-13-O-acetyl phorbol is added to the cultures. Ryanodine and TMB-8 are not inhibitors. The PHA-dependent Ca2+ response is significantly reduced when the cells are preincubated in the presence of the DHPs. Under these conditions, ryanodine has only a small inhibitory effect and TMB-8 has no effect. In contrast, only ryanodine (50 μM) decreases the PHA- dependent cytosolic release of Ca2+ when the cells are bathed in a medium containing a low concentration of Ca2+ (60 nM). The inhibitory effects of nifedipine and PN200-110 may result from the binding of these DHPs to specific receptor sites as revealed by studies using [3H]PN200-110 (KD - 8.5 ± 3.1 nM; 2300 ± 500 apparent binding sites/cell). Photoaffinity labeling studies using [3H]azidopine as a probe showed specific incorporation of label into three glycoproteins of molecular mass (± SD) 170 ± 13, 110 ± 25, and 60 ± 17 kd as analyzed by electrophoresis under reducing conditions. J. Leukoc. Biol. 53: 66–72; 1993.
Effect of acute oral administration of alcohol on superoxide anion production from mouse alveolar macrophages
Authors: Libon C , Forestier F , Cotte-Laffitte J , Labarre C , Quero AM
Published: January 2018

The production of superoxide anions (superoxide) from alveolar macrophages stimulated or not with opsonized zymosan was investigated in the mouse after acute oral administration of alcohol (6.5 g/kg). Superoxide production was assayed using a nitroblue tetrazolium (NBT) reduction and chemiluminescence assay. In the absence of opsonized zymosan, superoxide concentration was not affected 1 h after ethanol treatment but was significantly increased 15 and 24 h after treatment. In the presence of opsonized zymosan, a biphasic response was observed. Superoxide production was significantly reduced 1 and 3 h after administration but was increased 15 and 24 h after treatment. One hour after treatment, the percentage of cells that phagocytized opsonized zymosan and reduced NBT was significantly decreased, whereas 24 h after alcohol treatment, phagocytosis was normal and the percentage of cells reducing NBT was significantly increased. The activity of cytosolic superoxide dismutase from alveolar macrophages was not altered 1 h after administration but was significantly reduced 24 h later. Considering the functions of alveolar macrophages in the defense of the lung, these alterations in the production of reactive oxygen species after ingestion of alcohol could explain why alcoholics are more sensitive to pulmonary infections. J. Leukoc. Biol. 53: 93–98; 1993.
Endogenous nitric oxide inhibits the synthesis of cyclooxygenase products and interleukin-6 by rat Kupffer cells
Authors: Stadler Josef , Harbrecht Brian G , Di Silvio Mauricio , Curran Ronald D , Jordan Mark L , Simmons Richard L , Billiar Timothy R
Published: January 2018

Macrophage production of nitric oxide (•N=O) leads to considerable alterations of vital metabolic pathways in various target cells. The present study tested whether •N=O synthesis by Kupffer cells (KCs), the resident macrophages of the liver, interferes with the secretory function of these cells. As in other macrophage- type cells, the combination of lipopolysaccharide (LPS) and interferon-γ (IFN-γ) was a potent stimulus of •N=O synthesis by KC. Treatment with LPS and IFN-γ also induced significant production of prostaglandin E2 (PGE2), thromboxane B2 (TBX2), tumor necrosis factor α (TNF- α), interleukin-1 (IL-1), and IL-6. Inhibition of •N=O synthesis by the L-arginine analogue NG-monomethyl-L-ar- ginine (NMA) resulted in a further increase of PGE2, TXB2, and IL-6 but not IL-1 and TNF-α production, indicating specific inhibitory effects of endogenous •N=O synthesis on the secretory activity of KCs. PGE2 production was most sensitive to the suppressive effect of •N=O and increased 24 h after stimulation with LPS and IFN-γ from 16.3 ± 4.9 ng/106 KCs without NMA to 94.3 ± 17.9 ng/106 KCs with NMA. This effect of NMA was reversed by a 10-fold increase of the L-arginine concentration. No recovery of PGE2 production was seen when •N=O synthesis was blocked after 24 h. NMA treatment increased cyclooxygenase activity more than threefold, suggesting that •N=O inhibits PGE2 and TXB2 production through diminished PGH2 availability. •N=O synthesis did not significantly affect total protein synthesis or viability of the KCs. These results show that •N=O influences the production of specific inflammatory mediators by KCs. J. Leukoc. Biol. 53: 165–172; 1993.
Macrophage phenotype regulation by colony-stimulating factors at bone marrow level
Authors: Wijffels JFAM , de Rover Z , Kraal G , Beelen RHJ
Published: January 2018

Macrophages (mφs) can be divided into several subpopulations, which differ in phenotype, function, and localization patterns. However, little is known about the mechanisms that regulate this heterogeneity. We investigated whether mφ heterogeneity is regulated by colony-stimulating factors (CSFs) at the bone marrow level. By clonal expansion of bone marrow-derived precursor cells in die presence of CSF-1, granulocyte-macrophage CSF or multi-CSF (interleukin-3), phenotypic heterogeneity was observed between mφ colonies. Heterogeneity was found especially when different CSF culture conditions were used but also between mφ colonies derived under the same CSF culture condition. Our results illustrate that CSFs from the bone marrow hemopoietic microenvironment are important for the induction of phenotypic heterogeneity within the progeny of cloned mφ precursor cells during maturation and differentiation in vitro. J. Leukoc. Biol. 53: 249–255; 1993.
Distinct populations of antigen-presenting macrophages are required for induction of effector and regulatory cells in contac sensitivity response in mice
Authors: Szczepanik M , Bryniarski K , Pryjma J , Ptak W
Published: January 2018

Macrophages (Mf) and other antigen-presenting cells (APCs) are able to induce both immune and regulatory T cells. We compared the antigen-presenting activities of different subpopulations of thioglycolate-in- duced peritoneal macrophages from mice that were or were not treated with cyclophosphamide (CY) by several functional (adherence and phagocytosis) and morphologic (phenotypic) markers (FcR, Ia). Different subpopulations of macrophages were derivatized with trinitrophenyl and injected intravenously into recipients, which were tested directly for a contact sensitivity (CS) reaction or for the presence of efferent suppressor T (Ts) cells in passive transfer experiments. Our results demonstrate that peritoneal macrophages are both morphologically and functionally heterogeneous. Macrophages that induce immune cells that mediate CS have characteristics different from those that induce Ts cells. They accumulate in the low-density cell fraction on a discontinuous Ficoll gradient, are insensitive to treatment in vivo with low doses of CY, phagocytose poorly and adhere to plastic, and perhaps have low expression of FcRI and FcRII. Both macrophage fractions seem not to differ in expression of la, Mac-1, and Mac-3 antigens. It is argued that low doses of CY abrogate suppression in vivo by selective action on Ts cells. Our results confirm that at least a portion of the action of CY may be due to its influence on certain subpopulations of APCs. J. Leukoc. Biol. 53: 320–326; 1993.
Inflammation, immunoregulation, and inducible nitric oxide synthase
Authors: Nussler Andreas K , Billiar Timothy R
Published: January 2018

Nitric oxide (NO), the molecule of the year 1992, is gaining recognition as an important biological mediator. Its multitude of physiologic and pathophysiologic functions result from both a wide distribution of synthesis and diverse mechanisms of action. Besides its functions as a potent vasodilator and neurotransmitter, NO is important in inflammation and immunity. Both beneficial and detrimental consequences of induced synthesis have been discovered. Information is now accumulating on the regulation and function of induced NO. The recent cloning of human inducible NO cDNA should assist in defining the role of inducible NO in human physiology and pathophysiology.
The role of psychoneuroendocrine factors on spaceflight-induced immunological alterations
Authors: Meehan R , Whitson R , Sams C
Published: January 2018

This paper summarizes previous in-flight infections and novel conditions of spaceflight that may suppress immune function. Granulocytosis, monocytosis, and lymphopenia are routinely observed following short duration orbital flights. Subtle changes within the monocyte and T cell populations can also be noted by flow cytometric analysis. The similarity between the immunological changes observed after spaceflight and other diverse environmental stressors suggest that most of these alterations may be neuroendocrine-mediated. Available data support the hypothesis that spaceflight and other environmental stressors modulate normal immune regulation via stress hormones, other than exclusively glucocorticoids. It will be essential to simultaneously collect in-flight endocrine, immunologic, and infectious illness data to determine the clinical significance of these results. Additional research that delineates the neuroendocrine mechanisms of stress-induced changes in normal immune regulation will allow clinicians in the future to initiate prophylactic immunomodulator therapy to restore immune competence altered by the stress of long-duration spaceflight and therefore reduce morbidity from infectious illness, autoimmune disease, or malignancy.
Cell contact between T cells and synovial fibroblasts causes induction of adhesion molecules and cytokines
Authors: Bombara Michael R , Webb Deborah L , Conrad Patricia , Marior Christopher W , Sarr Timothy , Ranges Gerald E , Aune Thomas M , Grave Jeffrey M , Blue Marie-Luise
Published: January 2018

Human activated T cells adhere to synovial fibroblast-like cells in vitro. The present study was conducted to investigate the consequences of T cell-synovial fibroblast interactions with regard to induction of adhesion molecules and proinflammatory cytokines. A sensitive Western blot technique, polymerase chain reaction (PCR) amplification, and fluorescence-activated cell sorter (FACS) analysis were used to analyze the induction of VCAM-1 and ICAM-1 expression in T cell-synovial fibroblast cocultures. VCAM-1 and ICAM-1 expression could be induced in synovial fibroblast-like cells by 2 h. PCR amplification showed that both forms of VCAM-1 mRNA are found after the interaction of synovial fibroblasts with T cells. Up- regulation of VCAM-1 and ICAM-1 was confined to synovial fibroblasts; T cells did not express VCAM-1 or increased ICAM-1. In contrast to the T cell-synoviocyte interaction, the interaction between T cells and dermal fibroblasts resulted in the up-regulation of ICAM-1 but not VCAM-1, suggesting tissue-specific regulation of VCAM-1. The T cell-synovial fibroblast interaction also resulted in increased levels of tumor necrosis factor (TNF), interferon- 7, and interleukin-6 in coculture supernatant. Of the neutralizing antibodies used against these cytokines, only anti- TNF could significantly inhibit VCAM-1 and ICAM-1 expression. When T cells were separated from synoviocytes by a chamber that allowed medium exchange but no cell contact, VCAM-1 and ICAM-1 failed to be up-regulated and cytokine accumulation in cocultures was drastically reduced. Our results demonstrate mutual cell activation of T cells and synoviocytes upon cell contact as shown by the release of T cell- and synoviocyte-specific cytokines and suggest a cell contact-mediated and T cell-initiated mechanism for the chronic accumulation and retention of mononuclear cells via VCAM-l/ICAM-1 by synovial fibroblasts in the rheumatoid synovium.
Preincubation with anti-CD4 influences activation of human T cells by subsequent co-cross-linking of CD4 with CD3
Authors: Tsygankov Alexander Y , Brӧker Barbara M , Guse Andreas H , Meinke Uta , Roth Edith , Rossmann Cornelia , Emmrich Frank
Published: January 2018

Under physiological conditions, T cell activation by major histocompatibility complex (MHC)-anti- gen complexes requires engagement of both the T cell receptor (TcR) and the CD4 (or GD8) accessory molecules. It has been shown, however, that ligation of CD4 and GD8 can also inhibit T cell activation in an MHG-independent way. Therefore, the role of CD4 in T cell activation and the mechanism of the suppression of T cell functions by anti-CD4 are as yet unclear. We activated T cells by CD4/CD3 co-cross-linking and studied the effect of preincubation with anti-CD4 on this activation. We show here that anti-GD4 affects T cell activation in a complex, time-dependent manner. Whereas short preincubations with anti-GD4 usually enhanced T cell proliferation in response to subsequent co-cross-linking of CDS with GD4, longer preincubations led to its decrease. The observed suppression of proliferation after a long preincubation with anti-CD4 was apparently due to impairment of TcR signaling, as assessed by measurement of Ca2+ mobilization and tyrosine phosphorylation in T cells. These results add a temporal element to the previously observed synergism between the TcR and CD4 in T cell activation.
Granulocyte-macrophage colony-stimulating factor plays a role in the functional activity of mast cells
Authors: Meade Robin , Neddermann Kim M , Greenfield Robert S , Braslawsky Gary , Bursuker Isia
Published: January 2018

A peptide homologous to a region of murine granulocyte-macrophage colony-stimulating factor (mGM-CSF), P27-38, which was shown to be a GM-CSF antagonist, inhibited the function of serotonin release from murine mast cells. Peptide P27-38 inhibited immunoglobulin £ (IgE)-mediated serotonin release in a dose-dependent manner when induced by either specific antigen or anti-IgE antibody. In contrast, non-receptor- mediated release of serotonin by agents such as compound 48/80 or the calcium ionophore A23187 were not affected by the GM-CSF antagonist. Similar effects were observed with GM-CSF-neutralizing antibodies. The inhibitory effect of P27-38 and the neutralizing antibodies on serotonin release could be reversed by the addition of exogenous GM-CSF to the stimulated mast cells, indicating that the inhibitory activity was probably due to an effect on endogenously produced GM-CSF. These findings suggest that GM-CSF produced by stimulated mast cells is involved in the regulation of their activity in an autocrine manner.
Graded changes in the response of individual human basophils to stimulation: distributional behavior of early activation events
Authors: MacGlashan Donald W , Bochner Bruce S , Warner Jane A
Published: January 2018

These studies examine the distribution of single-cell responses in basophil preparations in the context of four events that may be associated with early activation by anti-immunoglobulin E (IgE) antibody and the bacterial peptide fMet-Leu-Phe (fMLP). In general, we measured the single-cell response distributions after challenge with a concentration of stimulus that resulted in an optimal response and compared this with the distribution that occurred after challenge with suboptimal concentrations of the same stimulus. The elevation in cytosolic calcium, as detected in Fura-2-labeled basophils, after challenge with anti-IgE or fMLP showed graded characteristics in that the distributions were unimodal under conditions of optimal or suboptimal challenge with little skewing from a normal distribution. Similarly, the up-regulation of the cell surface adhesion molecule CD11b, as determined by flow cytometry, showed graded unimodal increases after challenge with anti-IgE antibody at optimal and suboptimal concentrations. In addition, stimulation of basophils led to increased F-actin polymerization. After challenge with an optimal concentration of anti-IgE antibody, the F-actin content of basophils increased to a maximum between 10 and 15 min and returned to near prechallenge levels by 60 min. There was a close correlation between the maximum increase in F-actin content and histamine release regardless of the stimulus; anti-IgE antibody, fMLP, and phorbol ester (PMA) responses lay on the same regression line. The single-cell F-actin polymerization distributions were also unimodal and graded according to the magnitude of the histamine release response. During measurements of the calcium response under the microscope we noted that basophils underwent significant changes in morphology after challenge with any stimulus. These changes were related to both degranulation and nondegranulation events and could be quantitated by a series of imageprocessing algorithms, which are presented. The kinetics of the morphological change, measured as a change in cell perimeter, paralleled degranulation. Single-cell distributions of the morphologic changes were also unimodal under conditions of both optimal and suboptimal stimulation. Therefore, no evidence of all-or-nothing responses could be observed in the context of these four early activation events. In general, the response distributions resembled normal distributions at both optimal and suboptimal levels of stimulation, which indicated that single basophils responded in a graded manner. J. Leukoc. Biol. 55: 13–23; 1994.
Distinct patterns of differentiation induced in the monocytic cell line Mono Mac 6
Authors: Ziegler-Heitbrock H W Löms , Schraut Winfried , Wendelgaß Petra , Ströbel Marion , Sternsdorf Thomas , Weber Christian , Aepfelbacher Martin , Ehlers Monika , Schütt Christine , Haas Jürgen G
Published: January 2018

The human Mono Mac 6 cell line exhibits many characteristics of mature blood monocytes including expression of the CD14 molecule and production of cytokines, such as interleukin-1 (IL-1), IL-6, and tumor necrosis factor. To determine whether these cells can be further differentiated, we treated the cells for up to 3 days with either prostaglandin E2 (PGE2; 10-5 or 10-6 M), lipopolysaccharide (LPS; 10–20 ng/ml), or tetradecanoylbhorbol-13-acetate (TPA; 10–50 ng/ml). All three re-agents reduced proliferation and expression of the early myelomonocytic antigen CD33, and all increased phagocytosis of staphylococci and constitutive expression of mRNA for the macrophage colony-stimulating factor (M-CSF) receptor. By contrast, with respect to CD23 FcRII) expression, GD14 expression, and production of O2-, the three reagents induced distinct responses. Expression of CD23 (FcRII) on Mono Mac 6 cells (36%) was not increased by LPS and TPA but was increased by PGE2 treatment to 48%, with a 50% increase of fluorescence intensity. The CD14 antibody My4 stained more than 75% of untreated Mono Mac 6 cells with a specific mean fluorescence intensity of 87.5 channels. This staining was increased more than twofold by both PGE2 and LPS. Staining with the GD14 antibody UGHM1 (6%) was increased to 43% by PGE2 and to 43% by LPS. This increase in CD14 cell surface expression was accompanied by a rise in soluble CD14 and enhancement of CD14 mRNA. By contrast, TPA treatment resulted in a twofold decrease of CD14 cell surface staining with no significant change in sGD14, while CD14 mRNA was transiently down-regulated. Secretion of O2- (stimulated by TPA) was already detectable in untreated Mono Mac 6 cells 6.1 mmol/106 cells/30 min), and this response was enhanced 10-fold by pretreatment with LPS but not with PGE2 or TPA. The kinetics of M-GSF receptor mRNA, CD14 expression, and O2- production revealed that these monocytic features started to increase at 6–24 h and were maximal at 2 days. These data suggest that the three re-agents induce maturation of the Mono Mac 6 cells to different levels or into different branches of the monocyte system with the notable differences that PGE2 enhances CD23 expression, LPS enhances O2- secretion, and TPA down-regulates CD14. J. Leukoc. Biol. 55: 73–80; 1994.
Regulation of interferon-α-inducible cellular genes in human immunodeficiency virus-infected monocytes
Authors: Baca Lisa M , Genis Peter , Kalvakolanu Dhananjaya , Sen Ganes , Meltzer Monte S , Zhou Aimin , Silverman Robert , Gendelman Howard E
Published: January 2018

Cellular mechanisms that control susceptibility to opportunistic infection in human immunodeficiency virus (HIV)-infected individuals remain poorly understood. HIV may induce certain cellular genes that restrict HIV replication and protect cells against other superinfecting viral pathogens. Indeed, HIV-infected monocytes resist infection by vesicular stomatitis virus (VSV). HIV-induced VSV interference in monocytes increases with time after HIV infection. Such interference was evident 6 h after HIV infection and reached maximal levels at 14 days. Monocytotropic but not T cell-tropic HIV strains elicited these effects, signaling a requirement for viral entry and/or replication. Viral interference was independent of interferon (IFN) and was unaffected by addition of neutralizing IFN-α and -β antibodies. The well-described IFN-α-inducible antiviral pathways were examined to determine their relationship to the cellular mechanism(s) underlying VSV interference. HIV and IFN-α both induced the expression of 2–5A synthetase and Mx gene. In contrast, the guanylate-binding protein (GBP), 6–16, and 9–27 cellular genes were up-regulated by IFN-α but not HIV. MxA was detected in HIV-infected monocytes but not in uninfected monocytes. The association between Mx expression and resistance to VSV, coupled with previously described anti-VSV activities by human MxA, suggested that Mx may be an effector molecule for the HIV-induced anti-VSV activities. These results, taken together, suggest that HIV can induce antiviral cellular gene expression, independent of IFN. J. Lcukoc. Biol. 55: 299–309; 1994.
Legionella pneumophila inhibits superoxide generation in human monocytes via the down-modulation of α and β protein kinase C isotypes
Authors: Jacob T , Escallier J C , Sanguedolce M V , Chicheportiche C , Bongrand P , Capo C , Mege J L
Published: January 2018

Legionella pneumophila may subvert monocyte defenses by several mechanisms including the inhibition of phagosome-lysosome fusion or the impairment of oxidative metabolism. We have investigated the effect of L. pneumophila Knoxville 1, a virulent strain that does not inhibit phagosome-lysosome fusion, on the oxidative responsiveness of human monocytes. Infection of monocytes with L. pneumophila for 48 h resulted in marked inhibition of superoxide generation stimulated by phorbol myristate acetate (PMA) but not by zymosan, a particulate agonist. Evidence is provided that L. pneumophila interfered with the transductional pathway (i.e., protein kinase C, PKC) leading to activation of the NADPH oxidase in monocytes. The phosphorylation of 34-, 48-, 62-, 68-, and 80-kDa proteins stimulated by PMA was markedly inhibited in infected monocytes. In addition, the expression of both α and β PKC isotypes was partially inhibited in infected monocytes. Taken together, our data suggest that the down-modulation of PKC isotypes plays a role in the inhibition of PMA-stimulated superoxide generation. J. Leukoc. Biol. 55: 310–312; 1994.