bluuebunny/crossref_metadata_2025 huggingface dataset:
Recombinant bovine GM-CSF primes superoxide production but not degranulation induced by recombinant bovine interleukin-1β in bovine neutrophils
Authors: Tao Weng , Dougherty; Ruth , Johnston Paul , Pickett Walter
Published: January 2018

Bovine neutrophil activation, superoxide production, and β-glucosaminadase release induced by various biological stimuli were examined. Plateletactivating factor (PAF) and recombinant bovine interleukin-1 β (r-BoIL-1β) induced superoxide production and β-glucosaminadase release in bovine neutrophils. When these two responses were compared, the dose requirement for maximum activation was similar for PAF (1 × 10−6 M). However, the concentration of r-BoIL-Ι β required for the maximum degranulation (2.5 × 10−7 M) was 100-fold higher than that for the maximum superoxide production (2.5 × 10-9 M). Furthermore, pretreatment of cells with recombinant bovine granulocyte- macrophage colony-stimulating factor (r-BoGM-CSF) enhanced both superoxide production and β -glucosaminidase release induced by PAF. In contrast, whereas superoxide production induced by r-BoIL-1β was enhanced by r- BoGM-CSF priming, β -glucosaminidase release induced by r-BoIL-lβ was significantly reduced by pretreatment with r-BoGM-CSF. CL 184,005, a PAF antagonist, inhibited PAF-induced glucosaminidase release and superoxide production but did not inhibit r-BoIL-lβ -in- duced superoxide production and degranulation. In addition, it did not inhibit the priming effect of r-BoGM- GSF on r-BoIL-lβ -induced superoxide production. These results suggest that (1) PAF and r-BoIL-1β activate bovine neutrophils by different mechanisms, (2) r-BoGM-CSF primes superoxide production and degranulation induced by PAF, (3) r-BoGM-CSF primes superoxide production but not degranulation induced by r-BoIL-lβ, and (4) the priming effect of r-BoGM-CSF is not mediated by PAF. J. Leukoc. Biol. 53: 679–689; 1993.
Lipopolysaccharide-induced cytokine production and mortality in mice treated with Corynebacterium parvum
Authors: Smith Sidney R , Calzetta Angela , Bankowski Jennifer , Kenworthy-Bott Lynne , Terminelli Carol
Published: January 2018

Tumor necrosis factor a (TNF-α) has been shown to be an important mediator of the lethal effects of endotoxin in several experimental models of septic shock. However, studies with a recombinant human interleukin-1 (IL-1) receptor antagonist protein (IL-lra) suggest a role for IL-1 as a mediator of septic shock as well. In the present study, we show that mice treated in vivo with Corynebacterium parvum are primed for the production of interferon-γ (IFN-γ) and exhibit an enhanced capacity to produce serum IL-Ια, TNF-a, and IL-6 when challenged intravenously with lipopolysaccharide (LPS). The majority of C. parvum -treated mice die within 24 h of an LPS challenge. Pretreatment with a rat antimouse TNF-α monoclonal antibody (mAb) protected 90% of the animals against the lethal endotoxin challenge, while an anti-IFN-γ mAb gave approximately 75% protection. The anti-IFN-7fgamma; mAb also caused a reduction in LPS- induced serum TNF-α and IL-Ια. Anti-IL-la, anti- IL-1β, and anti-IL-6 neutralizing mAb did not protect against lethality when administered to mice prior to the LPS challenge. These results indicate that TNF-α and IFN-γ are major mediators of endotoxin shock in C. parvum-treated mice. The results further suggest that the IFN-γ produced by C. parvum-primed mice in response to an LPS challenge serves as a stimulus for enhanced production of TNF-α and IL-Ια. These findings are consistent with an increasing body of evidence suggesting a major role for IFN-γ in lethal endotoxemia.
Asbestos-induced injury to cultured human pulmonary epithelial-like cells: role of neutrophil elastase
Authors: Kamp David W , Dunne Moyra , Dykewicz Mark S , Sbalchiero Jane S , Weitzman Sigmund A , Dunn Marc M
Published: January 2018

The mechanisms responsible for asbestos- induced pulmonary epithelial cell cytotoxicity, especially oxidant-independent mechanisms, are not established. We determined whether human polymorphonuclear leukocyte (PMN) proteases contribute to asbestos-induced damage to human pulmonary epithelial-like cells (PECs) assessed using an in vitro chromium-51 release assay. Serine antiproteases, phenylmethylsulfonyl fluoride and αι -antitrypsin, each ameliorated PEC injury induced by amosite asbestos and PMNs. A role for a specific proteinase, human neutrophil elastase (HNE), is supported by the facts that (1) asbestos increased HNE release assessed by an enzyme-linked immunosorbent assay technique (1.7 ± 0.5 vs. 2.8 ± 0.5 μg/ml; P < .025), (2) purified HNE or porcine pancreatic elastase (PPE) each alone caused PEC detachment, (3) asbestos plus either HNE or PPE caused PEC lysis similar to that mediated by asbestos and PMNs, and (4) cationic agents released from PMNs were unlikely to be involved because polyanions did not ameliorate injury resulting from asbestos and PMNs. Compared to elastase, cathepsin G caused less PEC detachment and negligible augmentation in asbestos- induced PEC lysis. Asbestos increased the association of 125I-labeled elastase with PECs nearly 50-fold compared with PPE alone (14.4% vs. 0.3%, respectively; P < .01) and nearly 10-fold compared with another particle, opsonized zymosan. We conclude that PMN-derived proteases, especially elastase, may contribute to asbestos- induced lung damage by augmenting pulmonary epithelial cell injury.
Suppressive effect of interleukin-4 on the differentiation of M1 and HL60 myeloid leukemic cells
Authors: Yamashita Uki , Tanaka Yoshiya , Shirakawa Fumihiko
Published: January 2018

Abstract: The effect of interleukin-4 (IL-4) on the proliferation and differentiation of myeloid leukemic cell ines was studied in vitro. A culture of murine myeloid cell line, Ml, with lipopolysaccharide (LPS) from Escherichia coli, induced differentiation into macrophages that expressed Fc receptors and phagocytic ac- ivity. IL-4 did not induce the differentiation of Ml cells put inhibited the differentiation of Ml cells induced with LPS. On the other hand, LPS arrested the proliferation of Ml cells. IL-4 had no effect on the proliferation of Ml cells but restored the LPS-induced arrest of the proliferation of Ml cells. IL-1, IL-6 and tumor necrosis factor a (TNF-α) also induced the differentiation of Ml cells into macrophages and arrested proliferation. IL-4 suppressed the IL-1-, IL-6-, and TNF-induced differentiation of Ml cells and restored the arrested proliferation with IL-1, IL-6, and TNF. Similar results were obtained with human myeloid cell line HL60. These results suggest that IL-4 has a suppressive effect on the differentiation of myeloid cells into macrophages.
Immune changes during long-duration missions
Authors: Konstantinova Irena V , Rykova Marina P , Lesnyak Andrei T , Antropova Eugenia A
Published: January 2018

Immune changes during space flights in excess of two weeks have been almost exclusively studied by Russian investigators. Most of these studies have compared postflight values with those obtained before flight. In a very few cases, analyses have also been attempted during flight or with samples collected during flight. Studies of cosmonauts during spaceflight have shown that IgG levels were unchanged, whereas IgA and IgM levels were sometimes increased. Additionally, inflight delayed type hypersensitivity testing demonstrated a decrease below the warning level in 1/3 of the cosmonauts tested. Pre- vs. postflight analyses have often revealed a postflight decrease in: PHA-triggered lymphocyte blast transformation; the proliferation index of T-lymphocytes in the xenogeneic graft versus host reaction; the mitogen- induced production of interleukin-2; the presence of certain leukocyte sub sets; and cytotoxic activity of natural killer cells. Other factors that either did not change, or changed in an apparently random manner after flight included: production of α and γ interferon; autoimmune tests; and globulin classes.
Antibodies to macrophage stimulating protein (MSP): specificity, epitope interactions, and immunoassay of MSP in human serum
Authors: Wang Ming-Hai , Skeel Alison , Yoshimura Teizo , Copeland Terry D , Sakaguchi Kazuyasu , Leonard Edward J
Published: January 2018

Abstract: Macrophage stimulating protein (MSP) is a member of a family of proteins characterized by a triple disulfide loop structure (kringle). We developed antibodies to human MSP for detection in Western blots, quantification in biological fluids, and neutralization of activity. Immunogens included native MSP, reduced and alkylated α and β chains, and peptides of MSP regions with minimal sequence similarity to other kringle proteins. We found three antibody categories based on interaction with the following types of epitope: primary sequence, discontinuous (dependent on disulfide bonds), and cryptic (not exposed in native MSP). None of the antibodies reacted with related kringle proteins. A specific sandwich ELISA was developed for measuring human MSP. The mean serum concentration was 4 nM. Serum MSP did not increase over a 24-h period in response to intravenous lipopolysaccharide, indicating that MSP is not an acute phase protein. These findings are consistent with the hypothesis that regulation of MSP activity is by conversion of pro-MSP to MSP rather than by rapid changes in rates of synthesis.
Macrophage-tumor cell associations: a factor in metastasis of breast cancer?
Authors: van Netten J P , Ashmead B J , Parker R L , Thornton I G , Fletcher C , Cavers D , Coy P , Brigden M L
Published: January 2018

In human breast carcinomas tumor cells and macrophages are often proximal. We previously reported on the relationship between tumor cell growth and macrophage concentration and report here on the possible involvement of macrophages in the metastatic process. We hypothesize that during the initial stages of metastasis, tumor cells are likely to encounter macrophages and form aggregates. Using a cell culture method that encourages cellular interactions, we found aggregates involving macrophages. Macrophages partly or completely surround other cell types without any apparent ill effect. Units involving macrophages and tumor cells would possess many properties necessary for invasion, which is a normal process for macrophages. Properties such as motility and production of specific enzymes necessary to traverse the extracellular matrix, basement membrane, and endothelial cell barriers may provide an advantage for tumor cells. Physical support and protection from immune recognition during transport of the tumor cell through the vascular system may also be enhanced, and paracrine growth stimulation and angiogenic activity may be provided at the new metastatic site. Verification of these observations in vivo could lead to new directions for limiting breast cancer metastasis.
Receptor-receptor interactions of complement receptor type 3 in neutrophil membranes
Authors: Petty Howard R , Todd Robert R
Published: January 2018

The leukocyte integrin CR3 (GDllb/CD18) is known to participate in a variety of cell functions. Recent studies have indicated that CR3 may communicate with other plasma membrane receptors to carry out several cell functions. In this review we discuss these potential receptor-receptor interactions of CR3 and present a unifying model of GR3’s diverse functions.
Detection of intracellular interferon-γ by light microscopy using an immunoperoxidase technique: correlation with the corresponding mRNA and protein product
Authors: Dolhain Radboud J E M , Andersson Ulf , ter Haar Natalja T , Brinkman Brigitta M N , Verweij Cornells L , Daha Mohamed R , Breedveld Ferdinand C , Miltenburg Andre M M
Published: January 2018

Identifying individual cytokine-producing cells may help to acquire insight into immunological processes. This study was designed to adapt a technique for the detection of individual cytokine-producing cells from an immunofluorescence to an immunoperoxidase staining procedure. The production of interferon-γ (IFN-γ) by anti-CD3-activated cloned human T cells was used as a model system. After the conditions for the staining procedure were optimized, the immunoperoxidase technique was slightly more sensitive than the immunofluorescence technique. The intracellular staining for IFN-γ was preceded or paralleled by IFN-γ mRNA production and followed by accumulation of IFN-γ in the supernatant. It is concluded that intracellular IFN-γ can easily be detected using an immunoperoxidase procedure. This procedure is highly sensitive and allows quantification of the production of multiple cytokines by counting the percentage of positively staining cells.
Transient exposure of human eosinophils to the protein kinase C inhibitors CGP39-360, CGP41-251, and CGP44-800 leads to priming of the respiratory burst induced by opsonized particles
Authors: van der Bruggen Tjomme , Kbk Paul T M , Blom Michela , Verhoeven Arthur J , Raaijmakars Jan A M , Lammers Jan-Willem J , Koenderman Leo
Published: January 2018

We report that a transient incubation of human eosinophils with the protein kinase C (PKG) inhibitor CGP39-360 (staurosporine) or the more PKC-specific inhibitors CGP41-251 and CGP44-800 prior to activation of the respiratory burst with opsonized particles results in priming of this response. This priming effect was concentration dependent and occurred in the range in which the phorbol myristate acetate-induced respiratory burst was inhibited. CGP39-360 priming was minimally affected in Ca2+-depleted cells, indicating that an increase in [Ca2+]i is not important. Also, the binding of serum-treated zymosan (STZ) particles was strongly enhanced by the inhibitors. On the other hand, the release of plateletactivating factor (PAF) induced by opsonized particles was enhanced only by CGP39-360 and not by CGP41-251 and CGP44-800. Therefore, priming of the respiratory burst is not due to an aspecific enhancing effect of the inhibitors. These data indicate that different signal transduction routes are involved in priming of the STZ-induced respiratory burst and PAF release in human eosinophils.
Increased expression of a novel leukocytic factor in patients with hemolytic anemia
Authors: Larochelie André , Marceau Danièle , de Médicis Eveline
Published: January 2018

Misprimed polymerase chain reaction (PGR) products were generated from the crude leukocytic DNA extract of four of five patients with hereditary hemolytic anemia, during the course of exon 6 pyruvate kinase L gene amplification. These by-products, which originated from abundant mRNA templates, were not observed in seven healthy individuals. Two markers were cloned (GenBank accession numbers M64700 and M64701). We focused further studies on one of the human markers associated with hereditary hemolytic anemia, human DNA marker B (HUMDNAMB). HUMDNAMB is a 451-bp open reading frame that has never been described previously. The nucleic acid sequence region 303–416 is 63% homologous to a coding region of the bovine interferon α-A gene. Matrix analysis of the amino acid sequences reveals a structural similarity between the two proteins. The HUMDNAMB protein is expected to be larger than interferons, based on the size of its 2-kb messenger RNA detected by Northern blot in human leukocytes, fetal liver, and fetal intestine. J. Leukoc. Biol. 55: 1–6; 1994.
Ligation of N-acetylgalactosamine–containing structures on rat bone marrow cells enhances myeloid differentiation and murine granulocyte-macrophage colony-stimulating factor-induced proliferation
Authors: Krugluger Walter , Köller Marcus , Allmaier Martina , Boltz-Nitulescu George , Förster Othmar
Published: January 2018

Previously we have reported the differentiation-dependent expression of a soybean agglutinin (SBA)-binding structure on rat bone marrow cells (BMCs) during their differentiation into macrophages (møs). In the present study we tried to analyze the functional role of the SBA-binding structure in BMC proliferation and differentiation. Addition of SBA to BMC cultures driven into mø differentiation by recombinant murine granulocyte-macrophage colony-stimulating factor (rmGM-CSF), resulted in a two- to threefold increased proliferation rate compared with rmGM-CSF alone. However, the number of colonies in methyl cellulose was not increased by SBA. The effect of SBA was dose dependent (from 4 to 83 pM SBA), with a maximum effect at 83 pM. Experiments to detect a possible synergistic effect of additional cytokines produced by BMC after SBA treatment were inconclusive. The enhancing effect of SBA was also seen when high-density cells, which did not proliferate in response to rmGM-CSF (mainly granulocytes), were removed. Therefore, SBA may increase the CSF reactivity of re-sponsive mø progenitor cells directly by binding to N-acetylgalactosamine residues on their surface. J. Leukoc. Biol. 55: 127–132; 1994.
Effect of glycyrrhizin, cyclosporin A, and tumor necrosis factor α on infection of U-937 and MRC-5 cells by human cytomegalovirus
Authors: Numazaki Kei , Nagata Nobuo , Sato Toshiya , Chiba Shunzo
Published: January 2018

Reactivation of latent or persistent human cytomegalovirus (HCMV) infection of monocytes or macrophages occurs under immunosuppressive conditions. We investigated the effect of glycyrrhizin (GL), cyclosporin A (CsA), and tumor necrosis factor-α (TNF-α) on the viral DNA synthesis and antigen expression of HCMV in U-937 and MRC-5 cells. Although GL inhibited the viral antigen expression of HCMV in human monocytic cell line U-937 and human embryonic lung cell line MRC-5 in the study, as determined by flow cytometry and immunofluorescence assay, immediate early HCMV DNA was detected by the polymerase chain reaction. CsA or TNF had no inhibitory effect on HCMV in U-937 or MRC-5 cells. The HCMV infection model with U-937 or MRC-5 cells is of use for clarifying not only the mechanism of persistent infection but also the anti-HCMV effect of chemical agents. J. Leukoc. Biol. 55: 24–28; 1994.
The interleukin-4 receptor: signal transduction by a hematopoietin receptor
Authors: Keegan Achsah D , Pierce Jacalyn H
Published: January 2018

Over the last several years, the receptors for numerous cytokines have been molecularly characterized. Analysis of their amino acid sequences shows that some of these receptors bear certain motifs in their extracellular domains that define a family of receptors called the Hematopoietin receptor superfamily [1–3]. Significant advances in characterizing the structure, function, and mechanisms of signal transduction have been made for several members of this family. The purpose of this review is to discuss the recent advances made for one of the family members, the interleukin (IL) 4 receptor. Other receptor systems have recently been reviewed elsewhere [4–7]. The IL-4 receptor consists of, at the minimum, the cloned 140 kDa IL-4-binding chain with the potential for associating with other chains. The IL-4 receptor transduces its signal by activating a tyrosine kinase that phosphorylates cellular substrates, including the receptor itself, and the 170 kDa substrate called 4PS. Phosphorylated 4PS interacts with the SH2 domain of the enzyme PI-3′-kinase and increases its enzymatic activity. These early events in the IL-4 receptor initiated signaling pathway may trigger a series of signals that will ultimately lead to an IL-4 specific biologic outcome. J. Leukoc. Biol. 55: 272–279; 1994.
Diminished tyrosine protein kinase activity in T cells unresponsive to TCR stimulation
Authors: Tsygankov Alexander Y , Kim Ha W , Pratt Joanne C , Spana Carl , Class Kenneth , Gaulton Glen N , Kamoun Malek , Bolen Joseph B
Published: January 2018

Tyrosine phosphorylation is thought to be one of the earliest steps in antigenic activation of T cells. Three nonreceptor tyrosine kinases, p56lck, p60fyn, and ZAP-70, are known to be involved in T cell receptor (TCR) signaling, albeit their functional roles appear to be different. Whereas p60fyn and ZAP-70 are functionally associated with the T cell antigen receptor, p56lck is essential for TCR signaling without being directly coupled to the TCR. We have studied a mutant variant of the Jurkat T cell line (J32–3.2), in which basal activities of p56lck and p60fyn are 2- to 2.5-fold reduced relative to those in its parental line (J32) while basal activity of ZAP-70 remains unchanged, and compared responses of J32–3.2 and J32 to TCR stimulation. We have demonstrated that tyrosine phosphorylation following CD3 cross-linking in J32–3.2 cells was extremely short-lived and thus insufficient for the induction of subsequent physiological responses. This was at least partially due to the diminished tyrosine kinase activity in these cells. A decrease in the activity of src-related kinases was caused primarily by their lower expression, whereas expression of ZAP-70 was unchanged but its response to CD3 crosslinking was diminished, correlating with the deficient tyrosine phosphorylation of the CD3 -chain, recently observed in J32–3.2. These data are consistent with the idea that sir-related kinases phosphorylate the -chain, which in turn recruits ZAP-70 required to sustain the signal. J. Leukoc. Biol. 55: 289–298; 1994.
Coordinate and noncoordinate colony stimulating factor formation by human monocytes
Authors: Hamilton John A
Published: January 2018

The regulation of macrophage colony-stimulating factor (M-CSF) formation by elutriation-purified human monocytes was studied in vitro and compared with that for granulocyte-macrophage CSF (GM-CSF) and granulocyte CSF (G-CSF). The levels of the three CSFs were measured by immunoassay. Lipopolysac-charide (LPS, 100 ng/ml) was able to enhance CSF formation but the levels were significantly influenced by the presence of a cyclooxygenase product(s) in the cultures. In the presence of LPS, both M-CSF and GM-CSF were up-regulated by cyclooxygenase inhibition (indomethacin, 10-5 M), while G-CSF was down-regulated. Exogenous prostaglandin E2 (PGE2, 10-7 M) reversed the actions of indomethacin. In LPS-treated cells, in contrast to the different regulation by endogenous eicosanoid of M-CSF and GM-CSF formation and G-CSF formation, both interleukin-4 (IL-4, 250 pM) and the glucocorticoid dexamethasone (10-7 M) lowered the amounts of all CSFs. When the actions of CSFs were examined for their effects on CSF formation, M-CSF could not stimulate either GM-CSF or G-CSF synthesis, in contrast to literature findings, while GM-CSF enhanced M-CSF formation but not that of G-CSF. These studies indicate that there can be both coordinate and noncoordinate control of CSF expression by human monocytes. J. Leukoc. Biol. 55: 355–361; 1994.
LGL-1: a potential triggering molecule on murine NK cells
Authors: Mason Llewellyn H , Yagita H , Ortaldo John R
Published: January 2018

Natural killer (NK) cells mediate non-major histocompatibility complex-restricted lysis of tumor cells, lymphokine-activated killing (LAK), antibody-dependent cellular cytotoxicity (ADCC), and reverse ADCC (RADCC). LGL-1+ cells identify a major subset (50%) of murine NK cells. Here we demonstrate that monoclonal antibodies (mAbs) to LGL-1 consistently induce interleukin-2-cultured, and Corynebacterium parvum (in vivo)-activated NK cells to induce RADCC. LGL-1 triggering of activated NK cells coincides with enhanced LGL-1 expression. Testing of murine mAbs to epitopes of CD2 only appears to augment RADCC induced by mAb NK-1.1 on fresh NK cells. Immunoprecipitation of the LGL-1 antigen reveals a highly disulfide-linked 40-kDa homodimer subunit that is N-glycosylated. Therefore, LGL-1 may be similar to other recently characterized NK-associated antigens such as NK-1.1, Ly-49, and NKR-PI. We conclude that although LGL-1 is expressed on “resting” NK cells, enhanced surface expression following activation is usually required for it to act as a signaling molecule. J. Leukoc. Biol. 55: 362–370; 1994.
Transforming growth factor β: a matter of life and death
Authors: McCartney-Francis Nancy L , Wahl Sharon M
Published: January 2018

A wide variety of functions, many of which represent opposing activities, have been attributed to TGF-β, a molecule implicated in embryogenesis, development, and immune and inflammatory processes. This paradoxical behavior of promoting or inhibiting cell growth and function, while important in normal physiology and homeostasis, can contribute to or interrupt pathologic sequelae, making TGF-β a particularly intriguing molecule for study. New transgenic mouse models displaying targeted alterations in TGF-β1 expression offer novel and unique opportunities to determine the essential function(s) of TGF-β. J. Leukoc. Biol. 55: 401–409; 1994.
Transient expression of prostaglandin endoperoxide synthase-2 during mouse macrophage activation
Authors: Riese Jutta , Hoff Torsten , Nordhoff Axel , DeWitt David L , Resch Klaus , Kaever Volkhard
Published: January 2018

We investigated regulation of macrophage prostaglandin production during activation by interferonγ (IFN-γ) and lipopolysaccharide (LPS). An in vitro model was established using the mouse macrophagelike cell line RAW 264.7. Cells were cultivated in the presence of IFN-γ and LPS for up to 48 h and changes in the secretion of nitric oxide (NO) and tumor necrosis factor α (TNF-α) were observed as activation markers. Under these conditions a prompt and strong increase in PGE2 production was found in the first 8 h followed by nearly constant generation of PGE2 during the next 40 h. In contrast, the activity of prostaglandin endoperoxide synthase (PGHS), measured as PGE2 production of microsomal protein fractions, was also increased, but reached a clear maximum at 24 h. Recently a second form of PGHS was cloned (PGHS-2) and specific antibodies and mRNA probes for both isoforms are available. PGHS-2 enzyme was expressed maximally after 24 h of activation whereas PGHS-1 was not influenced. In the presence of IFN-γ and LPS, PGHS-2 mRNA expression reached a maximum at 8 h but PGHS-1 mRNA was not induced during the whole time period. These data indicate that changes in PG synthesis following macrophage activation are due to regulation of PGHS-2 expression. J. Leukoc. Biol. 55: 476–482; 1994.
Cloning and expression of the chicken CD18 cDNA
Authors: Bilsland Caroline A G , Springer Timothy A
Published: January 2018

The leukocyte integrins play a critical role in a number of cellular adhesive interactions during the immune response. We describe here the isolation and characterization of the chicken β2 (CD18) subunit, common to the leukocyte integrin family. The deduced 748-amino-acid sequence reveals a transmembrane protein with 65% and 64% identity with its human and murine homo-logues, respectively. The chicken β2 can associate on the cell surface with the human α subunit of LFA-1 and yields a hybrid molecule capable of binding to purified ICAM-1 and ICAM-3. J. Leukoc. Biol. 55: 501–506; 1994.
Differential expression of mast cell growth factor receptor (c-kit) by peritoneal connective tissue-type mast cells and tissue culture-derived mast cells
Authors: Chen Ben , Scheding Stefan , Nakeff Alexander , Ruan Qingyun
Published: January 2018

The peritoneal cavity of the mouse is a major source of connective tissue-type mast cells (CTMCs). Flow cytometric analysis using biotinylated recombinant murine mast cell growth factor (rMuMGF) showed that 1 to 3% of the cells in the peritoneal cavity exhibited MGF receptor (MGFR) (or c-kit). CTMCs were the only cell types expressing MGFR in the peritoneal cavity, and every one of them expressed MGFR. More than half the peritoneal CTMCs retained the potential to proliferate in the presence of recombinant murine interleukin 3 (rMuIL-3), rMuIL-4, and rMuMGF and gave rise to pure, alcian blue-positive “mast cells,” which actively expressed c-kit transcripts and MGFR. Flow cytometric analysis and receptor assay carried out at 4° showed that the number of MGFRs on culture-derived mast cells (CDMCs) was one-third that of peritoneal CTMCs (6 104 vs. 1.8 105 MGFR/cell). At 37°, the total number of membrane MGFRs detected in CDMC was two to three times more than that detected at 4°, indicating that nearly 70% of total MGFR in CDMCs, compared with only 40% in peritoneal CTMCs, existed as “cryptic sites” unable to interact with exogenous ligand at 4°. Thus, diminished expression of MGFR is one of the phenotypic characteristics associated with CDMCs. J. Leukoc. Biol. 55: 596–602; 1994.
The alternative complement pathway promotes IgM antibody-dependent and -independent adherence of Bacteroides to polymorphonuclear leukocytes through CR3 and CR1
Authors: Foreman Kimberly E , Bjornson Ann B
Published: January 2018

Natural immunoglobulin M (IgM) antibodies act synergistically with the alternative complement pathway to promote opsonization and adherence of Bacteroides thetaiotaomicron and Bacteroides fragilis to polymorphonuclear leukocytes (PMNs). This study characterizes the PMN receptors involved in adherence of Bacteroides opsonized by the alternative pathway and determines the effect of natural IgM antibodies on receptor involvement and on the molecular form of C3 deposited on the bacteria. A model system consisting of the six isolated proteins of the alternative pathway with or without supplemental isolated normal IgM was used for opsonization, and results were compared to those obtained with serum. The results demonstrate that the alternative pathway promotes adherence of Bacteroides to PMNs through complement receptors 1 and 3 (CR3), and epitopes in CR3 besides those mediating iC3b binding do not participate. The results also demonstrate that natural IgM antibodies do not influence the character of the ligands or receptors involved in this interaction. J. Leukoc. Biol. 55: 603–611; 1994.
Remodeling of the plasma membrane after stimulation of neutrophils with f-Met-Leu-Phe and dihydrocytochalasin B: identification of membrane subdomains containing NADPH oxidase activity
Authors: Mukherjee Goutam , Quinn Mark T , Linner John G , Jesaitis Algirdas J
Published: January 2018

Superoxide (O2-) production by neutrophils stimulated with chemotactic peptides [e.g., formylmethionylleucyl-phenylalanine (fMLP)] is transient but increases in rate and duration after pretreatment of the cells with dihydrocytochalasin B (dhCB), suggesting a possible role for the plasma membrane and membrane skeleton in the regulation of the O2- generating system. Analysis of plasma membrane isolated from these cells by isopycnic sucrose density gradient sedimentation showed that there were no significant variation in the distribution of plasma membrane markers between control and dhCB-treated cells, whereas a significant redistribution of plasma membrane markers was observed in dhCB + fMLP-treated cells. Instead of sedimenting to 31–35% sucrose, as in the former two groups, plasma membrane markers were broadly distributed over 25–50% sucrose in the dhCB+fMLP-treated cells. In addition, 80% degranulation was achieved in these cells, whereas little granule release (<5%) was observed in control and dhCB-treated cells. Analysis of the gradient fractions for membrane skeletal (actin and fodrin) and NADPH oxidase (cytochrome b and p47-phox) components in dhCB + fMLP-treated cells demonstrated that the distribution of fodrin, actin, cytochrome b, and p47-phox followed the broad distribution of plasma membrane markers, with an overall eightfold increase in membrane-associated actin. Despite the broad redistribution of plasma membrane markers, the distribution of O2- generating activity remained confined to a narrower peak at 50% sucrose. These results demonstrate that a heterogeneous surface membrane of higher density with a differential distribution of proteins and O2- generating activity are created after dhCB + fMLP treatment; however, domain structure is conserved in the new membrane, with only a subfraction of the reorganized plasma membrane containing all of the components necessary for active O2- generation. Our results support a role for plasma membrane lateral organization and participation of the membrane skeleton in the regulation of the O2- generating system. J. Leukoc. Biol. 55: 685–694; 1994.
Involvement of CD11b/CD18 in enhanced neutrophil adhesion by Fcγ receptor stimulation
Authors: Kusunoki Takashi , Tsuruta Satoru , Higashi Hideo , Hosoi Susumu , Hata Daisuke , Sugie Katsuji , Mayumi Mitsufumi , Mikawa Haruki
Published: January 2018

Neutrophils showed a rapid and transient adhesion to immunoglobulin G (IgG)-coated plates compared with their adhesion to bovine serum albumin (BSA)-coated plates: the adhesion reached a peak after 15 min of incubation and then gradually returned to almost the basal state in 60 min. The addition of monomeric IgG or anti-FcγRII monoclonal antibody (mAb) (IV.3) suppressed the increase in adhesion, whereas anti-FcγRIII mAb (3G8) was hardly effective, indicating that the interaction of FcγR, especially FcγRII, with coated IgG is involved in the process. Adhesion was also blocked by cytochalasin B, suggesting that functional actin filament structures are crucial. Protein kinase inhibitors, erbstatin and genistein, inhibited the adhesion in a dose-dependent manner. The adhesion was inhibited by anti-CDllb (Ml/70) and anti-CD18 (MHM23, TS1/18) mAbs. Moreover, neutrophils from a patient with complete leukocyte adhesion deficiency syndrome did not show increased adhesion to IgG-coated plates. The adhesion of neutrophils to fibrinogen- and BSA-coated plates was also increased when FcγR was stimulated in the fluid phase with soluble aggregated IgG, which was also inhibited by anti-CDllb mAb. Stimulation of neutrophil FcγR with soluble aggregated IgG enhanced the expression of CDllb in concert with the enhanced adhesion. These data collectively suggest that stimulation via FcγR evokes a tyrosine kinase-dependent and actin filament-dependent intracellular signal that enhances the specific and nonspecific adhesive activity of neutrophils, presumably through the activation of CDllb/CD18. J. Leukoc. Biol. 55: 735–742; 1994.
Differential effects of cAMP-elevating drugs on stimulus-induced cytosolic calcium changes in human basophils
Authors: Botana Luis M , MacGlashan Donald W
Published: January 2018

Drugs that elevate cAMP levels in human basophils are known to inhibit immunoglobulin E (IgE)-mediated histamine release. We have examined whether cAMP-active agents inhibit the cytosolic Ca2+, [Ca2+]i, response that normally accompanies activation of basophils. As previously described, this [Ca2+]i response is biphasic, one phase dependent on internal sources of calcium and a second later phase dependent on extracellular calcium, as observed in many cell types. Forskolin and rolipram or their combination had no effect on the initial elevation of cytosolic calcium that follows stimulation with anti-IgE antibody. In contrast, the second phase of the IgE-mediated calcium response was inhibited by these agents. For IgE-mediated responses, the relative efficacy of various cAMP active agents (rolipram forskolin < dibutyryl cAMP < forskolin + rolipram) for the inhibition of histamine release and the second-phase calcium response was similar and roughly paralleled the measured increase in basophil cAMP. In contrast, neither the first nor the second phase of the f-Met-Leu-Phe (fMLP)-induced calcium response was inhibited by any of the cAMP-active agents tested. Indeed, at low concentrations of fMLP, a combination of forskolin and rolipram caused slight enhancement of the calcium response. This result was consistent with the observations that these agents had no effect or caused slight enhancement of histamine or leukotriene released induced by fMLP. Similarly, cAMP-active agents caused no inhibition of C5a or phorbol ester (phorbol myristate acetate)-induced histamine release. These observations suggest that inhibition of the phase of the calcium response that is dependent on extracellular calcium could account for the inhibition of histamine release by these agents. However, these studies also suggested that (1) this is effect is not exerted at the level of the inositol trisphosphate (InsP3) receptor or InsP3 metabolism and (2) the mechanisms that maintain the second-phase calcium response are possibly distinct for IgE- and fMLP-mediated reactions because cAMP-active agents inhibited the second-phase response of only one stimulus. J. Leukoc. Biol. 55: 798–804; 1994.
Selective Mycobacterium avium–induced production of nitric oxide by human monocyte-derived macrophages
Authors: Dumarey Claude H , Labrousse Valérie , Rastogi Nalin , Vargaftig B Boris , Bachelet Maria
Published: January 2018

Infection with a virulent strain of Mycobacterium avium, but not with virulent Mycobacterium tuberculosis or avirulent Mycobacterium smegmatis, induced the formation of nitric oxide by human monocyte-derived macrophages. This process was not affected by lipopolysaccharide or cytokines such as interferon-γ or tumor necrosis factor α. M. avium-induced nitric oxide production was significantly decreased by NG-monomethyl-l-arginine, a potent inhibitor of nitric oxide synthase activity, without any significant enhancement of intramacrophagic mycobacterial growth. Infection with all the three mycobacterial species induced a significant activation of phospholipase A2 activity of macrophages as evidenced by the increased release of thromboxane A2. Finally, nitric oxide production by human monocyte-derived macrophages required infection with live M. avium, as neither gamma-irradiated M. avium nor the subcellular fractions of this microorganism (cell wall, cytosol) were able to trigger nitric oxide synthesis. J. Leukoc. Biol. 56: 36–40; 1994.
Human neutrophil respiratory burst response to influenza A virus occurs at an intracellular location
Authors: Kazhdan Misha , White Mitchell R , Tauber Alfred I , Hartshorn Kevan L
Published: January 2018

We have studied in detail the in vitro interactions of influenza A viruses (IAVs) with human neutrophils to clarify why these cells become dysfunctional during IAV infection. Unosponized IAV elicited a respiratory burst response in neutrophils which, like that triggered by formylmethionyl-leucyl-phenylalanine (fMLP), involved mediation of signal-transducing GTP-binding proteins and tyrosine kinase activation. The IAV-induced response differed from that provoked by fMLP in that H2O2 was produced without concomitant O2- release. IAV also did not cause extracellular release of granule enzymes in cytochalasin B-treated neutrophils. Using chemiluminescence assays, the respiratory burst response to IAV was found to occur at an intracellular location. These findings may, in part, explain the anomalous nature of the respiratory burst response elicited by IAV and suggest strategies for determining the mechanism of IAV-induced neutrophil deactivation. J. Leukoc. Biol. 56: 59–64; 1994.
Differentiated U937 cells exhibit increased bactericidal activity upon LPS activation and discriminate between virulent and avirulent Listeria and Brucella species
Authors: Caron Emmanuelle , Liautard Jean-Pierre , Köhler Stephan
Published: January 2018

In the study of interactions between facultative intracellular pathogens and macrophages, monocytic cell lines have the advantages of showing defined states of activation and lacking genetic variation among donors, thus yielding reproducible results. Nonpathogenic Escherichia coli K12 were killed at similar rates in the U937 cell line differentiated into macrophage-like cells by phorbol myristate acetate (PMA) or by the combination of retinoic acid (RA) and vitamin D3 (VD). Complete elimination was reached only when cells were activated by lipopolysaccharide for 30 min prior to infection, and it was further enhanced when bacteria were opsonized by specific immunoglobulin G. Both types of differentiation led to intracellular multiplication of virulent Listeria monocytogenes and to elimination of the animal pathogen Listeria ivanovii. For both strains, conditions for intracellular survival were more favorable in PMA-differentiated U937. During infection, RA/VD-differentiated U937 could discriminate between the human pathogen Brucella suis S1, which strongly multiplied, and the animal pathogen Brucella canis, which survived without multiplication. U937 cells differentiated by RA and VD therefore represent a basic model in bacteria-human macrophage interactions. J. Leukoc. Biol. 56: 174–181; 1994.
Evidence for the expression of three different BoLA-class II molecules on the bovine BL-3 cell line: determination of a non-DR non-DQ gene product
Authors: Ababou Assia , Goyeneche Julio , Davis William C , Lévy Daniel
Published: January 2018

Studies were conducted to determine the reactivity of six monoclonal antibodies specific for major histocompatibility complex class II molecules expressed on a bovine B cell line homozygous for BoLA-DR and BoLA-DQ alleles. Direct immunoprecipitation, serial immunodepletion experiments, and two-dimensional gel electrophoresis revealed that these antibodies reacted with three different molecules. Bovine orthologues of HLA-DR were recognized by three monoclonal antibodies—H34A, TH12A, and TH14B. Orthologues of HLA-DQ, were characterized by two other monoclonal antibodies, TH22A and TH81A. A third BoLA class II antigen, neither DR nor DQ was revealed by the last monoclonal antibody H42A. The relation of this molecule to known molecules in humans and other species remains to be established. However, cumulative data suggest that the determinant is expressed on a molecule related to HLA-DP. J. Leukoc. Biol. 56: 182–186; 1994.
Susceptibility of dendritic cells to HIV-1 infection in vitro
Authors: Cameron Paul U , Lowe Melinda G , Crowe Suzanne M , O’Doherty Una , Pope Melissa , Gezelter Stuart , Steinman Ralph M
Published: January 2018

We review recent work on the extent of HIV-1 infection of dendritic cells (DCs) and the consequences of exposure to virus. The reported levels of infection of DCs from blood have varied from “explosive” to “undetectable.” The only study that used sorted DCs demonstrated little if any infectability, which may not be surprising given the very low levels of CD4 on the populations that were studied. HIV-1-pulsed, highly purified DCs function as potent antigen-presenting cells during the mixed leukocyte reaction and responses to superantigens. At the same time that the HIV-1-pulsed DCs stimulate CD4+ T cells in DC-T clusters, the virus is transferred to the responding lymphocytes and a vigorous productive infection of the T cells takes place. This pool of transferable HIV-1 is short lived in cultured human blood DCs and likely reflects the capacity of these cells to internalize and recycle vesicles in the endocytic pathway, as revealed with experiments using 0.1-μm fluorescent latex beads. Current efforts are directed to analyzing the interaction of HIV-1 with several populations of DCs that express higher levels of CD4. These include DCs studied in fresh, uncultured blood, as well as skin, thymus, and tonsil DCs. In each case, entry and reverse transcription of HIV-1 are seen, but again, coculture with T cells is required for a productive infection to take place. We conclude that DCs could play a critical role in the pathogenesis of HIV-1 infection, but that the interaction with CD4+ T cells is a critical variable in analyzing the extent of productive infection and its consequences. J. Leukoc. Biol. 56: 257–265; 1994.
The HIV-1 regulatory protein Nef has a specific function in viral expression in a murine macrophage cell line
Authors: Murphy Kathleen M , Sweet Matthew J , Hume David A
Published: January 2018

Expression of reporter genes under the control of the HIV-1 long terminal repeat (LTR) was up-regulated in the murine macrophage cell line RAW264 by cotransfection of a plasmid coding for the viral regulatory protein Nef. To determine if a discrete section of the LTR was exclusively responsive to Nef, a series of promoters was produced by successive 5′ deletions from the LTR up to the boundary of the enhancer region. These truncated promoters were as active as the full-length sequence in the RAW264 cells, but elimination of the direct repeats and one of the three Sp1 sites reduced promoter activity to minimal levels. Transcription driven by all constructs was equally susceptible to the trans-activating effect of Nef and could be increased further by the addition of a Tat-expressing plasmid to the cotransfection. Open reading frames of nef from NL4-3, from HXB2, which has a premature stop, and a fully functional hybrid of the two under the control of the SRα artificial promoter (SV40 early promoter plus HTLV-I R-U5′) were able to trans-activate the LTR in RAW264 cells to the same degree as HXB3 nef under the control of the cytomegalovirus (CMV) immediate-early promoter. A frameshift mutation of Nef at the XhoI site at position 8475 did not abrogate trans-activation of the LTR in macrophages. To further define the effective trans-activation region of Nef, internal deletions were made. Changes downstream of the XhoI site at amino acid 35 resulted in little or no reduction in trans-activation, whereas a deletion between the CMV promoter of the expression plasmid and the XhoI site largely abolished activity. Nef trans-activation of the LTR may be restricted to macrophages. Parallel cotransfection experiments in COS-1 simian fibroblast-like cells showed repression of reporter expression by Nef. Results suggested that the section of nef responsible for trans-activation of the LTR in macrophages differed slightly from that sufficient for trans-repression in fibroblasts. Translation of the protein from the first translation start site (Met-1) rather than from the second in-frame ATG (Met-20) appears to be necessary for the trans-activating effect of Nef in RAW264 cells. Mutation of the initial ATG to ATA led to loss of trans-activating activity. Expression of Nef also has a cytostatic/cytotoxic effect on RAW264 cells indicated by a reduced rate of establishment of stably transfected clones. The cytostatic effect of Nef was not relieved by internal deletions in the coding sequence. The effect required transcription of one of two regions of the nef gene. These observations suggest that effects of Nef on cell growth and LTR-driven transcription in RAW264 cells are not related. Trans-activation of the HIV-1 LTR in the RAW264 cells by the regulatory protein Nef may be due to a novel protein-promoter interaction. J. Leukoc. Biol. 56: 294–303; 1994.
Intracerebral infusion of TNF-α and IL-6 failed to activate latent SIV infection in the brains of macaques inoculated with macrophage-tropic neuroadapted SIVmac
Authors: Joag Sanjay V , Adams Robert J , Pinson David M , Adany Istvan , Narayan O
Published: January 2018

Lymphocyte-tropic (L-tropic) SIVmac predictably causes immunosuppression and AIDS in rhesus macaques. SIV encephalitis, on the other hand, is caused mainly by macrophage-tropic (M-tropic) SIVmac. We have previously described the derivation of M-tropic, neuroadapted SIVmac from molecularly cloned, L-tropic SIVmac239. In this report we show that inoculation of four macaques with neuroadapted virus resulted in L-tropic SIVmac–related diseases in all four but neurological disease in only two of the four animals. Because cocultivation of infected macrophages with CD4+ lymphocytes results in production of tumor necrosis factor α and interleukin-6, we asked whether infiltration of supernatant fluids containing these cytokines into the brains of macaques infected with neuroadapted virus would enhance the development of neurological disease. These procedures failed to promote productive virus replication in the brain. Thus, although different degrees of immunosuppression and AIDS could be induced predictably with L-tropic virus, induction of neurological disease was not predictable even when animals were inoculated with neuroadapted M-tropic virus and inflammatory cytokines were infiltrated into the brains of these animals. J. Leukoc. Biol. 56: 353–357; 1994.