bluuebunny/crossref_metadata_2025 huggingface dataset:
In vivo distribution and characterization of two novel mononuclear phagocyte differentiation antigens in mice
Authors: Jutila Mark A , Berg Ellen L , Kroese Franz G M , Rott Lusijah , Perry Virginia , Butcher Eugene C
Published: January 2018

Flow cytometry, immunohistology, and SDS- PAGE Western blot analysis were used to characterize two novel anti-mouse mononuclear phagocyte differentiation antigens defined by monoclonal antibodies. One antibody, Monts-4, recognized an 80-100 kd cell-surface protein expressed on resident macrophages in the peritoneum and stained macrophages in the splenic white pulp and marginal zone, liver, lymph node paracortical regions, Peyers patches, and cortex of the thymus. Monts-4 did not stain blood monocytes or monocyte-derived inflammatory macrophages in the peritoneal cavity. Macrophages that were Monts-4 positive became Monts-4 negative within 24-72 h after culturing in vitro. Monoclonal antibody SK39 recognized a 180 kd cell-surface molecule expressed on inflamed peritoneal monocytes/macro- phages and stained macrophages in the splenic red pulp, cortex of the thymus, subcapsule and medullary regions of lymph nodes, and in sites of acute and chronic inflammation. No differences were seen in the expression of these antigens in the immunodeficient SCID versus normal BALB/c mouse. A comparison of the distribution and molecular weights of the Monts-4 and SK39 antigens with other described mononuclear phagocyte-specific antigens, including F4/80 and those defined by the Ml/70, ERTR9, MOMA1, MOMA2, and SER4 monoclonal antibodies, shows these to be novel mononuclear phagocyte-specific differentiation antigens.
Differential surface expression of cell adhesion molecules during granulocyte maturation
Authors: Lund-Johansen Fridtjof , Terstappen Leon W Μ M
Published: January 2018

Individual steps of granulocyte maturation, such as lineage commitment, proliferation, maturation, and migration from the marrow to the peripheral blood, may be influenced by distinct interactions with the bone marrow stroma. To identify candidates of membrane components involved in maturational stage-specific interactions, we studied changes in the expression of cell adhesion molecules along the granulocyte maturational pathway. Three-color flow cytometric measurements were used to measure levels of cell adhesion molecules along this pathway. The α chains of VLA-4 (CD49d) and VLA-5, the inte- grin 01 chain (CD29), and CD31 (PECAM-1) were expressed in high density on all early myeloid cells but down-modulated during postproliferative maturation. CD44 and L-selectin were expressed on CD34+ myeloid progenitor cells and mature granulocytes but down- modulated during the intermediate stages of maturation. The granulocyte receptor for endothelial selectins, sLex, was specifically expressed by myeloid progenitor cells. sLex was down-modulated during the intermediate stages of granulocyte maturation but up-regulated again during terminal maturation. In contrast, CD67, a putative granulocyte adhesion molecule, was negative on progenitors, transiently up-regulated during the intermediate stages of maturation, and almost absent from the surface of mature granulocytes. These results show that each stage of granulocyte maturation is associated with the expression of a unique combination of cell adhesion molecules. L-selectin, CD44, and 01 integrins were regulated as previously described for immature lymphopoietic cells and may therefore play general roles in the compartmen- talization and development of leukocytes. In contrast, sLex and CD67 were specifically expressed by myeloid cells and could be specifically important for compartmen- talization of distinct phases of granulocyte maturation.
Hepatic removal of 125I-DLT gelatin after burn injury: a model of soluble collagenous debris that interacts with plasma fibronectin
Authors: Blumenstock Frank A , La Celle Peter , Herrmannsdoerfer Axel , Giunta Corinne , Minnear Fred L , Cho Eshin , Saba Thomas M
Published: January 2018

The decline of plasma fibronectin after surgery, trauma, and burn, as well as during severe sepsis after injury, appears to limit hepatic Kupffer cell phagocytic activity. Intravenous infusion of gelatin-coated particles to simulate blood-borne particulate collagenous tissue debris in the circulation after injury also depletes plasma fibronectin. We used soluble gelatin conjugated with 1251-labeled dilactitol tyramine (DLT-gelatin) as a model of soluble collagenous tissue debris. We studied its blood clearance as well as organ localization in normal and postburn rats. Fibronectin-deficient plasma harvested early after burn exhibited limited ability to support in vitro phagocytic uptake of the gelatinized microparticles by Kupffer cells in liver tissue from normal rats. However, Kupffer cells in liver tissue from normal and postburn rats phagocytized the test particles at a normal rate when incubated in normal plasma. The DLT-gelatin ligand bound to fibronectin in a dose- dependent manner as verified by its capture with anti- fibronectin coated plastic wells when coincubated with purified fibronectin. By gel filtration chromatography, the binding of fibronectin with the DLT-gelatin ligand was readily detected, resulting in the formation of a high- molecular-weight complex. In normal animals the plasma clearance and liver localization of 125I-DLT-gelatin was competitively inhibited by infusion of excess nonradioactive gelatin. The blood clearance and liver localization of the soluble gelatin ligand were also impaired after burn injury during periods of fibronectin deficiency similarly to the pattern observed with gelatin-coated microparticles. By autoradiography, the cellular site for the uptake of the 1251-DLT-gelatin was primarily but not exclusively hepatic Kupffer cells; 125I-DLT-asialofetuin and 125I- DLT-ovalbumin were removed by hepatocytes and sinusoidal endothelial cells, respectively. Thus, gelatin conjugated with 125I-DLT can be used to simulate blood- borne soluble collagenous tissue debris after burn. It rapidly binds to plasma fibronectin before its hepatic Kupffer cell removal, and its blood clearance is markedly delayed after burn injury during periods of plasma fibronectin deficiency.
Lipopolysaccharide-induced suppression of erythrocyte binding and phagocytosis via FCγRI, FCγRII, FCγRIII, and CR3 receptors in murine macrophages
Authors: Sundaram Ramani , O’Connor Maeve , Cicero Mary , Ghaffar Abdul , Gangemi J David , Mayer Eugene R
Published: January 2018

Abstract: In this study we have investigated the ability of lipopolysaccharide (LPS) to suppress binding and phagocytosis of erythrocytes via various receptors on mouse macrophages. Thioglycollate-elicited peritoneal macrophages were treated in vitro with LPS and the ability to bind and phagocytose radiolabeled sheep red blood cells was determined. We show that LPS can directly suppress phagocytosis of immunoglobulin G-opsonized and nonopsonized sheep red blood cells (SRBCs) by inflammatory macrophages. Suppression was dose dependent and was observed after 4 h of exposure. This effect lasted for at least 24 h following the removal of LPS. LPS suppressed the binding, rate, and absolute level of phagocytosis via Fc receptors. Phagocytosis via all Fc receptors (FcγRI, FcγRII, and FcγRIII) was suppressed by LPS. Furthermore, suppression was not limited to Fc receptor-mediated phagocytosis because binding and uptake of C3bi-opsonized SRBCs to CR3 receptors was also decreased following LPS treatment. LPS did not exert its effects via the production of interleukin-1 (IL-1), IL-6, tumor necrosis factor a, or interferon a/β, because antibodies to these cytokines did not abrogate the effect. The ability of LPS to suppress binding and phagocytosis of microorganisms may contribute to the toxic effects of LPS during gram-negative sepsis by preventing or delaying elimination of bacteria by host macrophages.
Selective inactivation of lymphocytes after psoralen/ultraviolet light (PUVA) treatment without affecting systemic immune responses
Authors: Laskin Jeffrey D , Mermelstein Fred H , Heindel Ned D , Ron Yacov
Published: January 2018

Psoralens, together with ultraviolet light A (PUVA), are used for the treatment of several proliferative diseases. It has been suggested that the effectiveness of this treatment is due to induction of a specific immune response by PUVA-treated lymphocytes that down- regulates untreated cells of the same specificity. The present studies show that the clinically used psoralen analogue 8-methoxypsoralen (8-MOP), as well as 4,8-dimethyl- 5′-(pyridiniummethyl)psoralen bromide (4NQ), a derivative that does not cross the cell membrane, when activated by UVA light, render lymphocytes unresponsive to mitogenic, antigenic, or phorbol myristate acetate + ionomy- cin-induced stimulation. This state of unresponsiveness was not reversed by exogenous recombinant interleukin-2. Treatment of lymphocytes with 4NQ and UVA light had no effect on the viability or the homing pattern of the cells to spleen or liver, whereas 8-MOP induced toxicity in about 50% of cells after 3 days in culture. Using an adoptive transfer mouse model, we found that antigen- specific lymphocytes treated with PUVA (8-MOP or 4NQ) had no effect on the ability of these mice to respond to a subsequent challenge with the same or an irrelevant antigen. This was tested by measuring the T cell proliferative responses of lymph node cells from mice primed with keyhole limpet hemocyanin (KLH) or fowl gamma globulin (FGG) before or after adoptive transfer of large numbers of KLH- or FGG-specific PUVA-treated lymph node cells. No effects of antigen-primed PUVA-treated cells on antigen-primed untreated cells were observed in vitro in mixed lymphocyte cultures responding to the relevant antigen. These results suggest that, in our model system, PUVA induces cell inactivation but does not affect systemic T cell responses.
Response of blood leukocytes to thrombin receptor peptides
Authors: Hoffman Maureane , Church Frank C
Published: January 2018

Thrombin has receptor mediated effects on a variety of cell types. A recently cloned platelet thrombin receptor exerts its effects by a tethered-ligand mechanism. A similar receptor was shown in at least two nonplatelet cell types, fibroblasts and endothelial cells. Thrombin has biologically important effects on leukocytes, but the type of receptor mediating the effects is not known. Therefore, we examined the responses of monocytes, neutrophils, and lymphocytes to thrombin and to an agonist specific for the platelet-type thrombin receptor. We compared the effects of a peptide (SFLLRNPNDKYEPF) corresponding to residues 42-55 of the cloned platelet thrombin receptor on calcium flux in platelets and leukocytes. The thrombin receptor peptide induced increases in intracellular calcium in platelets and monocytes that reached a maximum at 5 μΜ peptide. The maximal increase was similar in magnitude to the response to thrombin. Lymphocytes showed a small and variable increase in intracellular calcium in response to thrombin or the thrombin receptor agonist. The thrombin receptor peptide had no effect on neutrophil calcium concentrations. When the amino acid corresponding to Arg 46 was replaced with Ala in the synthetic peptide, the ability to increase intracellular calcium was abolished for both platelets and monocytes. The peptide instead had thrombin antagonist activity. Thus, monocytes respond to thrombin receptor peptides similarly to platelets. We conclude that human monocytes possess a thrombin receptor similar to that present on platelets. Furthermore, the residue corresponding to Arg 46 of the thrombin receptor is critical for receptor agonist activity.
Activated neutrophils and neutrophil activators in human milk: increased expression of CD11b and decreased expression of L-selectin
Authors: Keeney Susan E , Schmalstieg Frank C , Palkowetz Kimberly H , Rudloff H Elizabeth , Le Binh-Minh , Goldman Armond S
Published: January 2018

Human milk neutrophils and macrophages were examined by flow cytometry to determine whether they displayed phenotypic markers of activation. The markers were CDllb and L-selectin, which are increased or shed, respectively, from the surface of activated neutrophils. Phenotypic features of milk neutrophils and macrophages were similar to blood neutrophils stimulated with fMLP: plasma membrane expression of CDllb was increased and L-selectin was decreased. After blood neutrophils were incubated in acellular milk, their expression of CDllb increased and L-selectin decreased. The activation was not affected by trypsin but was significantly decreased by treating acellular milk with chloroform or ether. Sedimentation studies suggested that particulate fractions of milk were active. Further, the activation was partly blocked by treating target blood neutrophils with cytochalasin B. Thus, human milk neutrophils are activated, and the activation may be due partly to phagocytosis of membranous structures in milk.
Inhibition of human mononuclear cell proliferation, interleukin synthesis, mRNA for IL-2, IL-6, and leukotriene B4 synthesis by a lipoxygenase inhibitor
Authors: Atluru Durgaprasadarao , Gudapaty Seshagirirao , O’Donnell Michael P , Woloschak Gayle E
Published: January 2018

Human peripheral blood mononuclear cells (PBMCs) were cultured in vitro with various stimuli and in the presence or absence of a 5-lipoxygenase (5-LO) inhibitor, A-63162, to measure its effects on PBMC proliferation, interleukin-2 receptor (IL-2R) expression, interleukin-2 (IL-2) synthesis, interleukin-6 (IL-6) synthesis, and accumulation of messenger RNA for IL-2 or IL-6. A-63162 inhibited PBMC proliferation stimulated by phytohemagglutinin (PHA) and phorbol myristate acetate (PMA) plus A23187, IL-2 receptor expression stimulated by PHA, and IL-2 or IL-6 synthesis induced by PHA plus PMA or PMA plus A23187. At the same concentration, A-63162 inhibited accumulation of mRNA for IL-2 or IL-6 and also inhibited leukotriene B4 (LTB.,) synthesis. Our data indicate that the 5-LO inhibitor A-63162 has immunosuppressive activity that may be due to inhibition of LTB4 production or to direct inhibitory actions of A-63162 on IL-2 and IL-6 synthesis.
Luminol-enhanced chemiluminescence induced in peripheral blood-derived human phagocytes: obligatory requirement of myeloperoxidase exocytosis by monocytes
Authors: Albrecht D , Jungi T W
Published: January 2018

Luminol-enhanced chemiluminescence (LCL) of phagocytes is often used to monitor for the generation of reactive oxygen mediators. A strong LCL reaction, as observed in triggered peripheral blood monocytes and neutrophils, depends on both the activation of an NAD(P)H-dependent oxidase and a functional myeloperoxidase (MPO). The aim of this work was to compare the LCL response induced by soluble and particulate stimuli in monocytes with that of polymoiphonuclear leukocytes (PMNs). In agreement with earlier results, neutrophils showed a first peak of LCL activity within 1 min and a second peak around 3 min when stimulated with soluble stimuli. The first peak is sensitive to oxygen scavengers and requires the presence of extracellular luminol, whereas the second peak is much less sensitive to oxygen scavengers and does not require the presence of extracellular luminol. The first peak of LCL is therefore thought to represent extracellular and the second peak intracellular LCL. Monocytes, in contrast, showed only the first peak of LCL activity. This peak was sensitive to oxygen scavengers, required the extracellular presence of luminol, and could be suppressed by a rapid pH shift to a pH not allowing LCL (L·, to pH 5). These results suggest that the stimulus-dependent extracellular release of oxygen metabolites and of MPO is an obligatory requirement for LCL induced in monocytes. An exclusively extracellular LCL was noted upon stimulation with aggregated immunoglobulin G, f-Met-Leu-Phe, phorbol myristate acetate, A23187, anti-CD36 antibodies, opsonized zymosan, and opsonized E. coli.. With the addition of H2O2 in excess (1 μΜ), the LCL response of monocytes therefore reflected the stimulus-dependent degranulation of MPO, and LCL-based determination of MPO release closely correlated with enzymatic MPO determination. The question of why LCL induced in monocytes, but not in PMNs, is restricted to the extracellular compartment was addressed. Although flow cytometric experiments were consistent with the hypothesis that extracellular H2O2 entered the cytoplasm of monocytes less efficiently than that of PMNs, other more important factors are assumed to contribute. Collectively, these results point to previously unrecognized differences in monocyte and PMN LCL which may reflect cellular differences of potential pathophysiological significance.
Analysis of interleukin-2-activated killer cells of rhesus monkeys: striking resemblance to the human system
Authors: Savary Cherylyn A , Lotzová Eva , Jackson Helen J , Jardine John H , Ang K Kian
Published: January 2018

We have found numerous and exquisite homologies between the interleukin-2 (IL-2)-activated killing systems of rhesus monkeys and humans. Lymphocytes with high oncolytic and proliferative activity were generated from peripheral blood, spleen, and bone marrow of monkeys sifter culture with IL-2. The distribution of lymphocyte subsets in IL-2 cultures closely paralleled that seen in humans, including a decrease in GD4+ and increase in CD8+, CD38+, and CD25+ lymphocytes and an increase in density of GD2 molecules. We also describe three distinct subsets of monkey lymphocytes, GD16+,56−, CD16+ 56+dim”, and CD16-,56bright, and show that the CD56+bright” subset is substantially increased (to as high as 79%) after IL-2 activation. Furthermore, as in humans, the cells with oncolytic activity were characterized as CD56+ CD16+-, and CD8+. This strong homology with humans indicates that the rhesus monkey may be a valuable preclinical model for evaluation of therapeutically relevant biological response modifiers.
Cytochalasin D inhibits lipopolysaccharide-induced tumor necrosis factor production in macrophages
Authors: Shinji Hitomi , Akagawa Kiyoko S , Yoshida Takeshi
Published: January 2018

We reported previously that a reorganization of microfilaments can be observed when macrophages are stimulated with lipopolysaccharide (LPS). This reorganization is not detected with current methods in macrophages of an LPS-nonresponsive C3H/HeJ mouse. These results suggest that the observed microfilament response might be involved in a macrophage-activating process induced by LPS. To investigate this, we studied the effect of cytochalasin D (CD), which inhibits reorganization of microfilaments, on LPS-induced tumor necrosis factor (TNF) production. A concentration of CD incapable of affecting filamentous actin by itself was used in these experiments. When this concentration of CD was added after LPS stimulation, microfilament reorganization and TNF production were inhibited. The suppressive effect of CD on TNF production was confirmed by the observation that TNF-α mRNA expression was also inhibited by CD. This inhibitory effect of CD was not specific to TNF, because the production of interleukin-1 and prostaglandin E2 were also inhibited. These effects of CD were observed only when CD was added within the first 20 min after LPS stimulation. These results suggest that the CD- sensitive microfilament response is essential in the signaling pathway for the production of certain monokines in LPS-stimulated macrophages.
Ex vivo clonotype primer-directed gene amplification to identify malignant T cell repertoires
Authors: Beers Teri , Du Tian-Long , Rickert Michael , Overturf Phyllis , Choi Youngnim , Greenberg Steven J
Published: January 2018

A novel strategy that utilizes input genomic DNA and overcomes limitations encountered with traditional RNA reverse transcription-polymerase chain reaction (PCR) amplification methodology is described to screen for T cell receptor (TCR) repertoires. The methodology has been developed to identify individual T cell clonotypes with regard to their unique receptor beta chain variable/diversity/joining (VDJ) region gene rearrangement. The technique avoids preselection for a given antigen specificity and is therefore independent of artificial bias introduced by in vitro cell population expansion. This technique was used to detect and identify genetically of malignant clones from heterogeneous mononuclear cell populations from an array of hemato- oncological disorders, including mycosis fungoides/Sézary Syndrome, adult T cell leukemia, and large granular lym- phoproliferative disease. An initial primary PCR, directed by a TCR-Jβ generic primer and a complement of family-specific TCR-Vβ primers, defines predominant T cell receptor variable gene usage. Use of a TCR-Jβ generic primer supplants the use of a constant region primer anchor and thus eliminates the need to target mRNA. The process of variable gene screening also expedites gene sequencing. By sequencing through the VDJ juxtaposed region, i.e·, the third complementarity determinant region, clonotype-specific primers are developed and used in a secondary clonotype primer-directed PCR (CPD-PCR) to detect, with extreme sensitivity and specificity, unique T cell clonal repertoires. Analysis of the products of the CPD-PCR permits the detection of a single malignant cell among one million polyclonal cells and supercedes the constraints of prior studies that provide a limited evaluation of family variable gene repertoire usage. This strategy may be applied in the detection of minimal residual disease, in surveillance after induction of disease-free states, and in analyzing the effectiveness of purging autologous bone marrow of malignant clones
Lipopolysaccharide and a phorbol ester stimulate secretion of tumor necrosis factor-α from alveolar macrophages through action on overlapping subsets of cells
Authors: Taylor Michael J , Hehnke Karen , Clark Cheryl L
Published: January 2018

A cell-by-cell analysis of the secretory ability of stimulated, individual alveolar macrophages (AMs) was performed through use of a tumor necrosis factor a (TNF-α) reverse hemolytic plaque assay. Two functional end points were measured: the percentage of AMs that were TNF-α secretors and the cumulative amount of TNF-α secreted by AMs (average plaque area, μm2). Lipopolysaccharide (LPS; 100 μg/ml) increased cumulative TNF-α release at both 7 and 20 h of incubation. On the other hand, a phorbol ester (phorbol myristate acetate, PMA) stimulated TNF-α release at 20 h of incubation but not at 7 h. Under nonstimulated culture conditions, 5-10% of all AMs released detectable TNF-α. PMA (but not LPS) induced a significant increase in the fraction of AMs capable of releasing TNF-α (15.1 ± 1.1% vs. 9.0 ± 1.6%, PMA vs. control, P < .05). Differences in the time course of secreted TNF-α, together with the recruiting effect of PMA, suggest that LPS and PMA target TNF-α- secretory subpopulations of AMs that differ in number and secretory characteristics.
Immunoglobulin G-mediated phagocytosis activates a calcium-independent, phosphatidylethanolamine-specific phospholipase
Authors: Lennartz Michelle R , Lefkowith James B , Bromley Frances A , Brown Eric J
Published: January 2018

Inhibition of arachidonate release down- regulates immunoglobulin G-mediated phagocytosis. This arachidonate requirement is selective for IgG- opsonized targets, suggesting that arachidonate may act as a second messenger for Fcγ receptor-mediated phagocytosis. Here we report the characterization of a phospholipase, activated during phagocytosis, that releases arachidonate from phosphatidylethanolamine in the absence of intracellular calcium ([Ca]i ≤ 2 nM). In vitro, a phospholipase with these characteristics was detected in soluble and particulate fractions of human monocyte homogenates. (E)-6-(Bromomethylene)tetrahydro-3-(l- naphthalenyl)-2H-pyran-2-one, a drug that selectively inhibits Ca-independent phospholipase A2S, is shown to inhibit IgG-mediated phagocytosis and its associated arachidonate release in intact monocytes as well as the in vitro enzyme activity. These findings provide a link between the whole-cell and in vitro data and present the initial characterization of a receptor-activated, calcium- independent phospholipase from human monocytes.
Differential effects of interferon-γ and glucocorticoids on FcγR gene expression in murine macrophages
Authors: Sivo Judit , Politis Alexander D , Vogel Stefanie N
Published: January 2018

Interferon-γ (IFN-γ) was shown previously to increase Feγ receptor (FcyR)-mediated binding and phagocytosis of immunoglobulin G-opsonized erythrocytes in mouse peritoneal exudate macrophages. Glucocorticoids potentiated this effect. We have extended these observations to an investigation of the effects of IFN-γ and glucocorticoids on steady-state mRNA levels of the three FcyR genes expressed on murine macrophages: FcyRI, FcγRII, and FcγRIIIα. FcγRI mRNA was present at a barely detectable level in unstimulated cells but was induced 5- to 10-fold by IFN-γ. FcγRIIIα mRNA was expressed constitutively and was induced significantly but very modestly (1.5-fold) by IFN-γ. FcγRII mRNA also exhibited high constitutive expression, but it was not altered by IFN-γ treatment. Dexamethasone (DEX) significantly increased the expression of IFN-γ-induced FcγRI mRNA but had no effect on the expression of FcγRII or FcγRIIIa transcripts in untreated or IFN- γ-treated cells. The effect of DEX on FcγRI mRNA was seen after about 10 h of simultaneous treatment with IFN-γ, was dose-dependent, and was glucocorticoid specific. DEX did not modulate the rate of decay of the FcγRI mRNA, suggesting that the up-regulatory effect of DEX may occur, in part, at the level of transcription. In the same culture system, the steady-state level of IFN- γ-induced Ia mRNA was concurrently inhibited by DEX. The up-regulation of the IFN-γ-induced high-affinity FcγRI mRNA, the failure to modulate the expression of the two low-affinity FcγR mRNA species, and the down- regulation of IFN-γ-induced la mRNA by DEX in the same cell population illustrate the diverse, gene-specific influence of glucocorticoids on the expression of IFN- γ-inducible genes.
Both mannose and β-glucan receptors are involved in phagocytosis of unopsonized, heat-killed Saccharomyces cerevisiae by murine macrophages
Authors: Giaimis Jean , Lombard Wes , Fonteneau Paul , Muller Christian D , Levy Rachel , Makaya-Kumba Madeleine , Lazdins Janis , Poindron Philippe
Published: January 2018

We studied the involvement of lectin-like receptors in phagocytosis of unopsonized heat-killed yeast (Saccharomyces cerevisiae) by murine macrophagelike cell lines and murine peritoneal resident macrophages. For this purpose we used a technique that allowed us to discriminate ingested and adsorbed heat-killed yeast. The internalization can be partly inhibited by soluble polyosides such as laminarin (β-glucan) or a- mannan. However, when they were used together (0.4 mg/ml α-mannan and 0.4 mg/ml laminarin), almost complete inhibition of phagocytosis was obtained. These observations suggest that phagocytosis of unopsonized heat- killed yeast by murine macrophage-like cell lines as well as murine peritoneal resident macrophages is mediated by both mannose and β-glucan receptors. The respective activity of these two types of receptors is a function of in vitro cell differentiation. To achieve maximal phagocytosis of unopsonized heat-killed yeast, coexpression of both mannose and β-glucan receptors is required.
Histamine modulation of Ca2+ homeostasis in human neutrophils
Authors: Leino Lasse , Tuominen Helena B , Åkerman Karl E O
Published: January 2018

The influence of histamine on the basal intracellular free Ca2+ concentration ([Ca2+]i) and agonist- induced increases of [Ca2+], was studied in Fura-2-loaded neutrophils. Histamine was unable to change the basal [Ca2+]i at concentrations (10−6-10-4 M) that have been shown to cause a rapid increase in [Ca2+]i in a variety of cell types. Histamine, in contrast, was found to inhibit dose-dependently the rise in [Ca2+]i induced by two neutrophil receptor agonists, IV- formylmethionyl-leucyl- phenylalanine (fMLP) and serum-opsonized zymosan particles. The histamine inhibition was shown to be specific for H2 receptor activation by blocking experiments with selective H1 and H2 receptor antagonists. In the absence of extracellular Ca2+, histamine failed to inhibit the agonist-induced rise in [Ca2*]i, indicating that histamine does not affect the release of Ca2+ from internal pools. Forskolin, which mimics the biochemical effects of H2 receptor activation by directly stimulating adenylate cyclase, also decreased the Ca2+ transients induced by receptor agonists. Similarly, 3-isobutyl-l-methylxanthine (IBMX), a phosphodiesterase inhibitor, reduced the Ca2+ response of activated neutrophils. These data suggest that in human neutrophils (1) no functional H1 receptors are present or alternatively H1 receptors are not coupled to cellular Ca2+ metabolism, and (2) H2 receptors modulate the receptor-triggered Ca2+ flux via the cAMP second messenger system.
Docosahexanoic acid (22:6, n-3) but not eicosapentaenoic acid (20:5, n-3) can induce neutrophil-mediated injury of cultured endothelial cells: involvement of neutrophil elastase
Authors: Bates Edna J , Ferrante Antonio , Harvey Dianne R , Nandoskar Madhuri , Poulos Alf
Published: January 2018

Previously published work has indicated that polyunsaturated fatty acids (PUFA) may enhance neutrophil-mediated damage to host tissues. We have found that endothelial detachment was significantly increased by neutrophils pretreated with docosahexaenoic (22:6, n-3) and arachidonic (20:4, n-6) acids at 10-40 μΜ but not by eicosapentaenoic acid (20:5, n-3). Endothelial cell lysis as measured by 51Cr release was unaffected. The extent of detachment was dependent on both fatty acid and neutrophil pretreatment concentrations. A specific leukocyte elastase inhibitor abrogated the increased detachment but catalase had no effect. Measurement of prostaglandin I2 synthesis as an alternative nonlytic assay of endothelial function indicated that 20:4 but not 20:5 was able to stimulate neutrophil-induced endothelial PGI2 synthesis. Although all three PUFA (3-33 μΜ) were found to stimulate release from neutrophil-specific granules, only 22:6 and 20:4 could stimulate release of the azurophilic granules containing elastase to any significant extent. Saturated fatty acids (20:0 and 22:0) and the methyl ester of 22:6 did not cause either neutrophil-mediated endothelial detachment or degranulation. We conclude that neutrophils pretreated with 22:6 or 20:4 but not 20:5 can decrease endothelial integrity through detachment involving neutrophil elastase. These findings may have important implications for the dietary use of fish oils rich in n-3 fatty acids.
Function and regulation of leukocyte homing receptors
Authors: Jutila Mark A
Published: January 2018

In vivo studies in the mid-1960s showed that lymphocytes home to various lymphoid compartments of the body in a tissue-specific manner. A central event in this process is adhesion of the leukocyte in the blood to specialized endothelial cells within the lymphoid organs. Leukocyte binding to the vascular endothelial cells involves many diverse adhesion molecules expressed by both cell types. Those adhesion molecules which contribute to the tissue specificity of the leukocyte-endothelial cell interactions are called “homing receptors.” The study of homing receptors has progressed tremendously in recent years. The intent of this treatise is to review our current understanding of these molecules in the context of the lymphocyte and outline studies showing that these molecules have important functions for other leukocytes as well. A general overview of leukocyte-endothelial cell adhesion will not be given: the reader can easily find many excellent and up-to-date reviews of this subject in the literature. This review is an attempt to outline the major contributions to the identification and characterization of homing receptors. Apologies are extended for any oversights made. J. Leukoc. Biol. 55: 133–140; 1994.
Hyperimmune serum modulates allergic response to spores in a murine model of allergic aspergillosis
Authors: Murali Pazhayannur S , Bamrah Bindu S , Choi Hongyung , Fink Jordan N , Kurup Viswanath P
Published: January 2018

Allergic bronchopulmonary aspergillosis (ABPA) is a disease in atopic asthmatics characterized by eosinophilia and elevated levels of immunoglobulin E (IgE) and IgG antibodies to the ubiquitous fungus Aspergillus fumigatus (Af). The role of specific antibodies in the disease process is not clear. In this study, BALB/c mice were injected with hyperimmune serum from syngeneic mice exposed to soluble antigen of Af. These mice were then exposed to either Af spores or soluble antigen. Total IgE, Af-specific IgG1 (enzyme-linked immunosorbent assay) in serum, and eosinophils (eosinophil peroxidase assay) in lungs and bone marrow were measured. Histologic sections of lungs were examined for cellular infiltration and morphologic changes. Results indicate a suppression of increase in levels of antibodies and eosinophilia in mice receiving immune serum and exposed to spores compared with controls receiving phosphate-buffered saline treatment. Spores being the primary source of exposure to Af in ABPA, these results are significant in understanding the role of preexisting specific antibodies in patients. J. Leukoc. Biol. 55: 29–34; 1994.
Activation of NF-κB may be necessary but is not sufficient for induction of H-2 antigens by TNF in J558L murine myeloma cells
Authors: Wolchok Jedd D , Goodman Adam R , Vilçek Jan
Published: January 2018

We have investigated the role of the transcription factor NF-κB in the induction of H-2 antigens by tumor necrosis factor (TNF) in murine J558L myeloma cells. An earlier report suggested that J558L cells may have a defect in NF-κB activation in response to some stimuli. Treatment of J558L cells with either TNF or lipopolysaccharide (LPS) resulted in nuclear translocation of NF-κB, as demonstrated by electrophoretic mobility shift assay. Both TNF and LPS activated the same NF-κB nuclear complexes, composed of the p50 and p65 subunits. LPS mediated a stronger and more sustained activation of NF-κB than TNF. In contrast, TNF induced higher levels of H-2 antigen surface expression than did LPS, suggesting that activation of NF-κB is not sufficient for optimal enhancement of H-2 expression. An inhibitor of NF-κB activation, pyrrolidinedithiocarbamate (PDTC), dramatically reduced the induction of H-2 antigen by TNF, supporting the view that NF-κB is required for TNF-induced H-2 antigen expression. Constitutive levels of H-2 antigen expression on the cell surface and of nuclear NF-κB also decreased after PDTC treatment. However, PDTC had a smaller inhibitory effect on LPS-induced NF-κB activation and H-2 antigen expression, suggesting that TNF and LPS activate NF-κB by somewhat different pathways. J. Leukoc. Biol. 55: 7–12; 1994.
Leishmania donovani infection enhances macrophage viability in the absence of exogenous growth factor
Authors: Moore Kathryn J , Turco Salvatore J , Matlashewski Greg
Published: January 2018

Bone marrow-derived macrophages rapidly die in the absence of macrophage growth factor (M-CSF). However, as demonstrated here, bone marrow-derived macrophages infected with Leishmania donovani exhibit increased viability in the absence of exogenous growth factor. Forty-eight hours after inoculation with promastigotes or amastigotes, infected cell cultures contained 180 and 95% more cells, respectively, than control cultures. This effect was specific to Leishmania infection, as uptake of latex beads or avirulent promastigotes by macrophages did not enhance cell viability. L. donovani-infected macrophages also displayed increased phagocytic capacity, as compared with control macrophages and macrophages grown continuously in M-CSF-containing medium. Supernatants collected from infected cells elaborated a factor(s) that enhanced macrophage viability but did not stimulate macrophage DNA synthesis. This activity of L. donovani-infected cell-conditioned medium could be abrogated by preincubation of macrophages with cycloheximide before inoculation with the parasite, implying that macrophage protein synthesis is required for the elaboration of this factor(s). J. Leukoc. Biol. 55: 91–98; 1994.
Secretion of TNF-α by alveolar macrophages in response to Candida albicans mannan
Authors: Garner Ronald E , Rubanowice Katherine , Sawyer Richard T , Hudson John A
Published: January 2018

Resident alveolar macrophages (AMø) were tested for their ability to respond to Candida albicans mannan. AMø were found to produce tumor necrosis factor alpha (TNF-α) in vitro in response to mannan stimulation. TNF-α secretion was measured using ELISA and L929B cellular cytotoxicity assays. Cytotoxicity was neutralized in parallel L929B cell cultures by the addition of rabbit anti-TNF-α antibody. Mannan preparations were found to be free of contaminating LPS by Limulus assay. When AMø were cultivated for 18 h at 37°, 67 μg of mannan stimulated the secretion of approximately 207 U/ml of TNF-α. By comparison, AMø treated with 6.7 μg of LPS secreted approximately 257 U/ml of TNF-α. Optimal TNF-α production occurred between 9 and 18 h after mannan stimulation. Disparate mechanisms for stimulation of TNF-α secretion were suggested by differential sugar blockade of LPS- and mannan-induced TNF-α secretion. The addition of 2% D-mannose or 2% alpha-methyl-D-mannoside to AMø cultures blocked mannan-but not LPS-stimulated TNF-α secretion. Furthermore, the addition of rabbit anti-mannan antibody to mannan-coated plastic culture dishes prevented TNF-α secretion by the mannan-sensitive RAW 264.7 cell line. Moreover, the data suggest that C. albicans mannan stimulated AMø to secrete TNF-α by an LPS-independent receptor mechanism which may also function as a mannose receptor. J. Leukoc. Biol. 55: 161–168; 1994.
Inhibition of human interferon-gamma expression by antisense oligodeoxynucleotides
Authors: Boeve Christine M A , De Ley Marc
Published: January 2018

We investigated 12 antisense oligodeoxynucleotides, complementary to different regions of the human interferon-γ (HuIFN-γ) gene, for their ability to inhibit HuIFN-γ production in cultures of single donor total leukocytes or lymphocytes (95% purity). Out of seven oligomers, specific for a sequence including the translation initiation codon, 15 to 21 nucleotides long, the one resulting in the greatest inhibition was the 16-mer. An inhibitory effect of 90% could be achieved when the oligomer was added to cultures of lymphocytes in separate doses. Three other 16-mers, complementary to a sequence in the 5′ noncoding region, in the coding region, or at the donor splice junction of the third intron respectively, were inhibitory to a lesser extent. Two 16-mers, one complementary to a sequence at the donor splice junction of the second intron and one specific for a sequence in the 3′ untranslated region, showed no effect. J. Leukoc. Biol. 55: 169–174; 1994.
Inhibition of activation-induced death in T cell hybridomas by thiol antioxidants: oxidative stress as a mediator of apoptosis
Authors: Sandstrom Paul A , Mannie Mark D , Buttke Thomas M
Published: January 2018

N-Acetylcysteine (NAC) is a well established thiol antioxidant which, after uptake, deacylation and conversion to glutathione functions as both a redox buffer and a reactive oxygen intermediate scavenger. We report here that NAC completely blocks activation induced death and associated DNA fragmentation of myelin basic protein (MBP) specific T cell hybridomas. Conversely, NAC had very little effect on the antigen driven proliferation of a MBP specific T cell line similar to that from which the hybridomas were derived. NAC displayed an analogous absolute inhibition of mitogen mediated activation induced death, even if added up to 3 h post activation. Although glutathione was as efficient as NAC at blocking activation induced death, dithiothreitol displayed minimal inhibition while L-cysteine had no effect at all. The observation that certain thiol antioxidants such as NAC and glutathione can completely block the activation induced death of T cell hybridomas implicates redox regulation in this process. J. Leukoc. Biol. 55: 221–226; 1994.
Activation of macrophages for cytolysis of virally infected cells by monoclonal antibody to the 73-kDa lipopolysaccharide receptor
Authors: LeBlanc Paul A
Published: January 2018

The abilities of lipopolysaccharide (LPS) and mAb5D3 (a monoclonal antibody specific for the 73 kDa LPS receptor) to activate bone marrow culture derived macrophages (BMCM) for cytolysis of vesicular stomatitis virus infected BALB/c3T3 (VSV-3T3) and the tumor target, P815, were compared. Activation for cytolysis of VSV-3T3 cells occurred at a lower level of either LPS or mAb5D3 than activation for cytolysis of P815. With both targets and under several stimulation conditions there was a constant differential between the two activating stimuli. These data indicate that stimulation of the 73 kDa LPS receptor at low levels of either mAb5D3 or LPS can activate BMCM for cytolysis of VSV-3T3 but not P815. Further, the constant relative efficiency of mAb5D3 to LPS in both target systems suggests that there is a common receptor for both LPS mediated effects. J. Leukoc. Biol. 55: 262–264; 1994.
Antineutrophil monoclonal antibody (1F12) alters superoxide anion release by neutrophils and Kupffer cells
Authors: Bautista Abraham P , Spolarics Zoltan , Jaeschke Hartmut , Smith C Wayne , Spitzer John J
Published: January 2018

The formation of oxygen-derived radicals by phagocytes is regulated by chemotactic agents, cytokines, and adhesion molecules, such as CD11b/CD18 (Mac-1). In the rat system, we investigated the effect of monoclonal antibody 1F12 against rat neutrophils on hepatic sequestration of neutrophils and superoxide release by hepatic phagocytes. Within 15 min after 1F12 injection, there was profound neutropenia, which persisted for 24 h. The majority of the “lost” neutrophils were sequestered in the liver 4 h after treatment. Zymosan-induced superoxide release in vitro by isolated hepatic neutrophils from 1F12-treated rats was significantly attenuated at 4 and 24 h. The phorbol myristate acetate mediated superoxide release was inhibited 24 h after treatment. Superoxide anion release by normal adherent neutrophils in the presence of agonists was also inhibited by 1F12 in vitro. The in vivo administration of 1F12 primed the Kupffer cells to release superoxide. In vitro treatment of Kupffer cells with 1F12 also stimulated superoxide release. Monoclonal antibody WT.3 (also directed against rat neutrophils), which does not cause neutropenia, did not alter superoxide generation by neutrophils and Kupffer cells. These results indicate that 1F12 may be useful in attenuating inflammation and tissue injury associated with neutrophil activation. However, the activation of Kupffer cells to release toxic oxygen-derived metabolites may predispose the liver to injury in certain pathological conditions. J. Leukoc. Biol. 55: 328–335; 1994.
Targeting HIV-1 to FcγR on human phagocytes via bispecific antibodies reduces infectivity of HIV-1 to T cells
Authors: Howell Alexandra L , Guyre Paul M , You Kwan-sa , Fanger Michael W
Published: January 2018

In addition to CD4, the primary receptor to which the human immunodeficiency virus type 1 (HIV-1) binds, mononuclear phagocytes (monocytes) express three classes of Fc receptors for immunoglobulin G (FcγR). We have previously shown that infection of monocytes by HIV-1 is inhibited when bispecific antibodies (BsAbs) are used to target the virus to either the type I, type II, or type III FcγR on these cells. Infection of monocytes was not inhibited when HIV-1 was targeted to either human leukocyte antigen class I or CD33. We have extended these studies to examine the ability of BsAbs plus polymorphonuclear leukocytes (neutrophils, PMNs) and monocytes to reduce infectivity of HIV-1 to cells from the human T cell lymphoma line, H9. The production of HIV-1 following interaction of virus with BsAb and phagocytes was determined in an indicator cell assay by mixing BsAb, HIV-1, and phagocytes with uninfected H9 cells. Productive infection of H9 cells was quantitated on subsequent days by measuring p24 gag antigen levels in supernatants by enzyme-linked immunosorbent assay. Our findings show that the addition of interferon-γ-activated PMNs or monocytes to cultures of HIV-1 plus H9 cells in the absence of BsAb results in a marked reduction in p24 levels equivalent to 85 to 90% of control levels. With the combination of BsAb (anti-FcγRI anti-gpl20) plus IFN-γ-activated phagocytes, levels of p24 in H9 cultures were below those at culture initiation. These findings demonstrate that IFN-γ-activated phagocytes can affect the natural course of HIV-1 infection of T cells, a finding of potential clinical importance. J. Leukoc. Biol. 55: 385–391; 1994.
Rapid modification of ribosomal S6 kinase II (S6KII) in rabbit peritoneal neutrophils stimulated with chemotactic factor fMet-Leu-Phe
Authors: Huang Chi-Kuang , Coleman Herman , Stevens Tim , Liang Li
Published: January 2018

The ribosomal S6 kinase II (S6KII) in rabbit neutrophils was studied by immunoblotting with antibodies prepared against recombinant S6KII. A protein with apparent molecular weight of 80,000 Da in SDS-gel was recognized by the antibodies. A shift of the apparent molecular weight to 84,000 Da in SDS-gel was observed in cells stimulated with the chemotactic factor fMet-Leu-Phe. Cytochalasin B and phorbol 12-myristate 13-acetate, but not A23187, stimulated both the tyrosine phosphorylation of p41mapk and the change of the mobility of S6KII. Pretreatment of the cells with quin 2/AM inhibited almost completely the tyrosine phosphorylation of p41mapk induced by fMet-Leu-Phe, but only partially the change in mobility of S6KII. Under various conditions, near maximum conversion of S6KII was observed even if only about 40% of the maximum level of tyrosine phosphorylation of p41mapk was achieved. The results suggest that rapid modification of S6KII occurs in chemotactic factor-stimulated neutrophils. Furthermore, the modification of S6KII induced by fMet-Leu-Phe requires either only partial tyrosine phosphorylation of p41mapk or the activation of kinase(s) other than the p41mapk isoform. J. Lcukoc. Biol. 55: 430–436; 1994.
Interleukin-10 is a potent inhibitor of tumor cytotoxicity by human monocytes and alveolar macrophages
Authors: Nabioullin Roustem , Sone Saburo , Mizuno Kazuto , Yano Seiji , Nishioka Yasuhiko , Haku Takashi , Ogura Takeshi
Published: January 2018

The effects of purified human interleukin-10 (IL-10) on the expression of antitumor activity of human monocytes and alveolar macrophages (AMs) obtained by centrifugal elutriation and bronchoalveolar lavage, respectively, from the same healthy donors were examined. Monocytes and AMs were incubated for 16 h in medium with lipopolysaccharide (LPS) in the presence or absence of IL-10 or IL-4, and then their tumoricidal activity was assayed by measuring 125I-IUdR release from human melanoma (A375) cells. Addition of IL-10 to cultures of monocytes or AMs with LPS resulted in dose-dependent suppression of their cytotoxicity against A375 cells, the suppression of the activity of monocytes being the higher. IL-10 also suppressed the synergistic effects of interferon-γ and desmethyl muramyldipeptide in activation of monocytes. IL-10 inhibited the early induction phase of monocyte activation but not the effector phase (monocyte-mediated cytotoxicity). IL-10 plus IL-4 inhibited the antitumor activities of AMs and monocytes much more than either IL-10 or IL-4 alone. IL-10 and IL-4 at sub-optimal concentrations also showed synergistic inhibitory effects. These findings suggest that IL-10 may be important in vivo in down-regulating the antitumor activities of monocytes and AMs in the lung by inhibiting their productions of antitumor effector molecules. J. Leukoc. Biol. 55: 437–442; 1994.