bluuebunny/crossref_metadata_2025 huggingface dataset:
Short amino acid sequences derived from C1q receptor (C1q-R) show homology with the alpha chains of fibronectin and vitronectin receptors and collagen type IV
Authors: Ghebrehiwet Berhane , Peerschke Ellinor I B , Hong Yuqun , Munoz Priscilla , Gorevic Peter D
Published: January 2018

The human C1q receptor (C1q-R) is a 65–70-kd, highly acidic, hydrophobic glycoprotein that is expressed on a wide variety of cell surfaces. Although the C1q-R itself appears to bind preferentially to C1q, the region of the ligand to which C1q-R binds is the primary binding site for several other molecules, including fibronectin, laminin, and C1q inhibitor (chondroitin 4-sulfate proteoglycan) as well as the complement C1r2C1s2 tetramer. In order to further characterize the C1q-R molecule with regard to its structure and function, highly purified C1q-R was obtained from Raji cells using DEAE-Sephacel and C1q-Sepharose CL-4B chromatography. Studies performed with 125I-labeled C1q-R demonstrated that whereas the C1q-R molecule binds poorly to a variety of human collagens including types II, III, and V, markedly enhanced binding is observed with type IV collagen and moderately enhanced binding with type I collagen. Amino acid composition studies show that the C1q-R molecule contains approximately 44% hydrophobic and 12.6% hydrophilic residues with a ratio of negatively charged to positively charged residues of about 2:1. Treatment of 125I-labeled C1q-R with endoglycosidase F lowers the apparent molecular size from 70 to 58 kd, whereas endoglycosidase H lowered the size to 64 kd. Treatment with neuraminidase, on the other hand, shifted the size of C1q-R to 60 kd. These results suggest the presence of several highly sialylated complex-type or high mannose–type N-linked oligosaccharide side chains. Because purified C1q-R has a blocked amino terminus, amino acid sequences representing internal fragments of the molecule were generated by electroblotting and in situ enzymatic digestion. When these short sequences were searched against the National Biomedical Research Foundation computer data base, a seven-amino-acid sequence, VSWQGQI, showed significant homology (100% and 80% in a five-amino-acid overlap, respectively) with the α chains of the human fibronectin (α5β1) and vitronectin (αvβ3) receptors, and to a lesser degree with epidermal growth factor receptor and T cell receptor. A second sequence, ISEDNIR, showed homology with mouse collagen type IV (86% in a six-amino-acid overlap), calmodulin (60% in a seven-amino-acid overlap), and a Leishmania major surface antigen, gp63. These observations seem to predict that C1q-R has pockets of conserved sequences that are similar to those not only present in its ligand(s) but also in other cell surface receptors that may, in part, fulfill similar functions.
Superoxide generation by the human polymorphonuclear leukocyte in response to latex beads
Authors: Thomas Michael J , Hedrick Catherine C , Smith Sharon , Pang Jian , Jerome W Gray , Willard Andra S , Shirley Pamela S
Published: January 2018

In this study, superoxide formation was not immediately detected when polymorphonuclear leukocytes were treated with linoleyl alcohol–coated, carboxy-modified latex beads. However, all other measures of neutrophil activation were present. Superoxide was not detected until 30 min after the initial exposure to beads. However, an O−2-producing, NADPH-dependent oxidase is active 15 min after exposure. When polymorphonuclear leukocytes are pretreated with cytochalasin B, superoxide production is detected immediately after exposure to the beads. Superoxide secretion after treatment with linoleyl alcohol–coated latex beads is compared with the response to other latex beads. The results imply that neutrophils form a phagolysosome around linoleyl alcohol–coated latex beads that is tightly sealed and does not allow superoxide to escape into the medium where it could be detected by the reduction of ferricytochrome c.
Development, differentiation, and proliferation of epidermal Langerhans cells in rat ontogeny studied by a novel monoclonal antibody against epidermal Langerhans cells, RED-1
Authors: Mizoguchi Suzuhiko , Takahashi Kiyoshi , Takeya Motohiro , Naito Makoto , Morioka Tohru
Published: January 2018

An antirat monoclonal antibody (mAb) against nonlymphoid dendritic cells, RED-1, was produced using epidermal Langerhans cells (LCs) as the immunogen. This mAb reacted mainly with the LCs and indeterminate dendritic cells (ICs), interdigitating cells in the T cell areas of lymphoid tissues, and monocyte/macrophages in various organs and tissues of adult rats. In the epidermal sheets prepared from adult rats, it specifically recognized the cell surface antigen(s) present on LCs and ICs. In the fetal rat skin, primitive or fetal macrophages migrated into the epidermis and expressed RED-1 at fetal day 17. With advance of gestation, RED-1–positive cells increased, started expressing Ia antigens at fetal day 18, and subsequently differentiated into dendritic cells. Most of them showed Ia expression by fetal day 20 and differentiated into LCs within a few days after birth. The labeling index of 5-bromo-2′-deoxyuridine in RED-1–positive cells was 18% at fetal day 17 and decreased to 5 to 6% in the postnatal period. These results imply that proliferative capacity of RED-1–positive cells is important for the formation and expansion of the IC population in the fetal stage and for the survival of LCs in the postnatal period.
Tumor antigen presentation by epidermal antigen-presenting cells in the mouse: modulation by granulocyte-macrophage colony-stimulating factor, tumor necrosis factor α, and ultraviolet radiation
Authors: Grabbe Stephan , Bruvers Sandra , Lindgren Ann M , Hosoi Junichi , Tan Kong C , Granstein Richard D
Published: January 2018

I-A+ epidermal antigen-presenting cells (APCs, Langerhans cells) have been shown to present tumor-associated antigens (TAAs) and to induce tumor immunity in vivo. This study examined the effects of ultraviolet radiation (UVR) and the cytokines granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor α (TNF-α) on the ability of epidermal cells (ECs) to induce or to elicit immunity against the murine spindle cell tumor S1509a. Naive syngeneic mice were immunized three times at weekly intervals with ECs that had been cultured in GM-CSF for 18 h and then pulsed with TAA derived from S1509a. This resulted in protective immunity against subsequent tumor challenge, providing a model to study the conditions required for sensitization against TAAs by epidermal APCs. Culture of ECs in GM-CSF was required for induction of significant protective tumor immunity, and UV irradiation or incubation in TNF-α for 2 h after GM-CSF incubation abrogated the immunostimulatory effect of GM-CSF. However, unlike UVR, TNF-α did not significantly inhibit the induction of immunity when ECs were exposed to TNF-α before overnight incubation in GM-CSF, together with GM-CSF, or after pulsing with TAA, and anti-TNF-α antibody treatment did not abrogate the effects of UVR on this system. Furthermore, TNF-α incubation of ECs augmented their ability to elicit delayed-type hypersensitivity (DTH) and also enhanced elicitation of DTH by GM-CSF–cultured ECs, whereas UV-irradiation reduced it in a dose-dependent fashion. Taken together, these results demonstrate that GM-CSF, TNF-α, and UVR are significant regulators of tumor antigen presentation by epidermal APCs and that the effects of the cytokines examined differ with regard to induction or elicitation of immunity.
Differential effects of interleukin-4 on superoxide anion production by human alveolar macrophages stimulated with lipopolysaccharide and interferon-γ
Authors: Bhaskaran Geetha , Nii Akihiko , Sone Saburo , Ogura Takeshi
Published: January 2018

The effect of interleukin-4 (IL-4) on the activation state of human alveolar macrophages (AMs) and blood monocytes induced by lipopolysaccharide (LPS) or recombinant interferon-γ (IFN-γ) was investigated on the basis of their ability to produce superoxide anion (O2-). AMs were obtained from healthy donors by bronchoalveolar lavage, and O2- productions of these cells were assayed by a cytochrome c reduction method after incubation with stimulants for 24 h. AMs produced more O2- than autologous blood monocytes when stimulated with LPS. IL-4 alone had little effect on O2- production by unstimulated AMs but down-regulated O2- production by LPS-stimulated AMs in a dose-dependent manner. IL-4 also suppressed O2- production by AMs induced by the synergistic actions of muramyl dipeptide (norMDP) and IFN-γ. Maximum suppression by IL-4 of O2- production by AMs was observed when IL-4 was added within 1 h after initiation of LPS stimulation. AMs also showed high O2- production when stimulated with IFN-γ alone. In contrast to its suppression of O2- production by LPS-stimulated AMs, IL-4 enhanced O2- production by AMs stimulated with IFN-γ. These data suggest that IL-4 is an important regulator of O2- production by macrophages through different pathways depending on the stimulus.
Constitutive production of PAI-II and increased surface expression of GM1 ganglioside by peripheral blood monocytes from patients with AIDS: evidence of monocyte activation in vivo
Authors: Auci Dominick L , Chice Seto M , Durkin Helen G , Murali Mandakolathur R
Published: January 2018

To characterize the activation state of monocytes during human immunodeficiency virus (HIV) infection, peripheral blood monocytes (PBMs) from patients with acquired immunodeficiency syndrome (n = 10) and from healthy controls (n = 10) were cultured for 4 days. Monocyte culture supernatant (MCS) was collected daily, and levels of urokinase (UK) inhibitor PAI-II, a product of activated monocytes, released into MCS were determined (fibrin plate assay). To examine the activation state of PBMs independently, expression of GM1 ganglioside on PBMs from patients with AIDS (n = 9), patients with AIDS-related complex (ARC) (n = 8), HIV+ asymptomatic patients (n = 6), and HIV” healthy controls (n = 11) was determined (flow cytometry; living cells in suspension). Data are expressed as percent inhibition of UK, or as percent total cells. Patients' MCS collected on days 1–4 of culture contained similar levels of PAI-II because it inhibited UK in similar fashion (70–90%). In contrast, MCS from healthy controls, collected after 2 days, had decreased ability to inhibit UK (15–50%) and thus contained lower levels of PAI-II. Monocyte activation, measured by increased expression of GM1 ganglioside on PBM surfaces, directly correlated with the progression of HIV infection into the development of AIDS, since the order of magnitude of GM1 ganglioside expression on PBMs was AIDS > ARC > HIV+ asymptomatic = healthy controls. Our data indicate that PBMs from patients with AIDS are constitutively activated and suggest that activation directly correlates with disease progression.
Differential induction of prostaglandin E2-dependent and -independent immune suppressor cells by tumor-derived GM-CSF and M-CSF
Authors: Oghiso Yoichi , Yamada Yutaka , Ando Koichi , Ishihara Hiroshi , Shibata Yoshimi
Published: January 2018

Both prostaglandin E2 (PGE2)-dependent (indomethacin-sensitive) and PGE2-independent (indo-methacin-insensitive) suppressor cell activities that inhibited mitogenic T cell blastogenesis appeared in the bone marrow and spleen of mice on days 20 to 30 following transplantation of NFSA fibrosarcoma molecularly expressing mRNA for both macrophage (M) and granulocyte-macrophage (GM) colony-stimulating factors (CSFs). The present study was done to characterize the two different suppressor cells isolated from NFSA tumor-bearing mice and to verify a role of CSFs in the induction of suppressor cells in vitro. Whereas PGE2-releasing suppressor cells were found in bone marrow and spleen cells isolated from tumor-bearing mice, indomethacin-insensitive suppressor cells in both tissues were localized predominantly in adherent cell fractions. An increase in Mac-1+ and Mac-2+ spleen cell populations with two to three times larger cell volumes was observed, and both showed strong PGE2-releasing capacity and indomethacin-sensitive suppressor cell activity. However, after elimination of Mac-1+ or Mac-2+ cells, bone marrow cells still showed higher PGE2-releasing capacity and indomethacin-sensitive suppressor activity. The in vitro cultures of normal bone marrow and spleen cells with NFSA cell conditioned medium (NFSA-CM) induced heterogeneous mixtures of indomethacin-sensitive and -insensitive suppressor cells like those observed in cultures with the combination of M-CSF and GM-CSF. However, cultures with either GM-CSF or M-CSF resulted in the induction of indomethacin-sensitive suppressor cells by GM-CSF and of indomethacin-insensitive suppressor cells by M-CSF. In addition, NFSA-CM pretreated with anti-GM-CSF antibody induced indomethacin-insensitive suppressor cells in in vitro cultures of bone marrow and spleen cells. These results suggest that two distinctly different suppressor cells developed under hemopoiesis of myelomonocytic lineage cells are regulated differentially by the two macrophage growth factors, M-CSF and GM-CSF. J. Leukoc. Biol. 53: 86–92; 1993.
Tumor necrosis factor-α induction by reovirus serotype 3
Authors: Farone Anthony L , O’Brien Patricia CM , Cox Donald C
Published: January 2018

We have reported previously that reovirus, when used in combination with 1,3-bis(chloroethyl)-1- nitrosourea (BCNU) chemotherapy, mediates the rejection of murine ascites tumors. Surviving animals reject a challenge with the same, hut not a different, tumor, which suggests that tumor-specific immunity is induced by the treatment regimen. The present study was designed to characterize the interaction between reovirus and murine peritoneal macrophages, both in vitro and in vivo, to determine whether such a relationship may play a role in immune modulation resulting in tumor rejection. The results demonstrated that reovirus can efficiently infect peritoneal macrophages in vitro and stimulate the secretion of tumor necrosis factor-alpha (TNF-α). In vivo administration of reovirus, however, did not produce high levels of infection in peritoneal exudate cells, even though the cells were stimulated to express detectable levels of membrane TNF-α. These results suggested that infection is not necessary for TNF-α expression and this hypothesis was supported by the observation that this expression was also stimulated in vitro by UV-inactivated reovirus. These findings suggest that one mechanism for immune stimulation by reovirus may be through the induction of TNF-a.—Farone, AX., O’Brien, P.C.M., Cox, D.C. Tumor necrosis factor-α (TNF-a) induction by reovirus serotype 3. J. Leukoc. Biol. 53: 133–137; 1993.
Inhibition of tumor cell mitochondrial respiration by macrophage cytotoxic mediators distinct from interferon-γ
Authors: Tucker Stanley D , Auzenne Edmond J , Sivaramakrishnan Mathoor R
Published: January 2018

Macrophage-mediated inhibition of mitochondrial respiration in EMT-6 murine mammary adenocarcinoma cells can be mimicked in vitro by treatment of the cells with interferon-γ (IFN-γ) in combination with tumor necrosis factor, interleukin-1, or lipopolysaccharide. Conditioned supernatants obtained from activated macrophages appear to contain interferon-γ, suggesting that inhibition of mitochondrial respiration in tumor cells was caused by synergy of IFN-γ with other cytokines. To further characterize monokines that cause inhibition of mitochondrial respiration in tumor cells, EA13.5 macrophage-like cells were isolated and selected for inhibition of mitochondrial respiration in EMT-6 tumor cells. After stimulation with IFN-γ and lipopolysaccharide, the EA13.5 cells released into conditioned supernatants a cytotoxic mediator that induced nitric oxide synthesis and caused lesions in the electron transport chain of EMT-6 cells similar to the lesions caused by activated peritoneal macrophages. Enzyme-linked immunosorbent assay demonstrated that the conditioned supernatants produced by EA13.5 macrophage cells did not contain IFN-γ. Treatment of the EA13.5 cell-conditioned supernatants with neutralizing antibody against IFN-γ did not abrogate the inhibition of mitochondrial respiration in EMT-6 cells caused by these conditioned supernatants. This study demonstrated that unidentified macrophage cytotoxic mediators distinct from IFN-γ are involved in the induction of nitric oxide synthesis and inhibition of mitochondrial respiration in tumor cells. J. Leukoc. Biol. 53: 138–143; 1993.
Relationship between macrophage colony-stimulating factor production by uterine epithelial cells and accumulation and distribution of macrophages in the uterus of pregnant mice
Authors: De Mamata , Sanford Thomas , Wood Gary W
Published: January 2018

Estrogen and progesterone induce production of macrophage colony-stimulating factor (CSF-1) by uterine epithelial cells, and CSF-1 is produced in the uterus during pregnancy in mice. CSF-1 is a lineage-specific stimulator of macrophage proliferation, chemotaxis, and function. High concentrations of macro-phages accumulate in the uterus during pregnancy. Ex-periments were conducted to determine whether a relationship exists between intrauterine CSF-1 production and the number and distribution of uterine macrophages during pregnancy in mice. The study demonstrated that on day 1 of pregnancy CSF-1 bioactivity levels were high. The number of macrophages in the uterus was also high on days 1 and 2, and macrophages were concentrated at epithelial surfaces. The decrease in CSF-1 bioactivity seen between days 1 and 2 was followed by a decrease in the macrophage concentration. An increase in CSF-1 bioac-tivity on day 4 was followed by an increase in the con-centration of intrauterine macrophages. During the im-mediate postimplantation period, macrophages were detected primarily in the myometrium and deep en-dometrium and CSF-1 bioactivity was undetectable. During the second half of pregnancy, when CSF-1 con-centrations were very high, the macrophage concentration was also very high and large numbers of macrophages were detected in association with epithelia. The data confirmed the existence of a direct relationship between intrauterine CSF-1 and macrophage accumulation and suggested that macrophages are attracted to epithelial surfaces by CSF-1. J. Leukoc. Biol. 53: 240–248; 1993.
In vitro invasiveness of CTL clones and in vivo dissemination of CTL hybridomas
Authors: La Rivière Geertie , Gebbinck Jacqueline WTM Klein , Schipper Cor A , Mooi Wolter J , Roos Ed
Published: January 2018

Activated spleen T cells are invasive in hepatocyte and fibroblast cultures, and this property is dominantly expressed in T cell hybridomas. The invasive potential of the hybrids correlates with their capacity to disseminate in vivo. We have used this model to study the invasive and migratory properties of cytotoxic T lymphocytes (CTLs). TWo murine CTL clones were highly invasive, independent of their state of activation. CTL hybridomas, derived from one of the clones, were similarly invasive. In vivo, CTL hybridoma cells disseminated to extravascular sites in the liver, kidneys, lungs, ovaria, tubae, uterus, and lymphoid, mesenchymal, and fat tissues. Within 7 to 14 days, 106 cells were lethal in 100% of mice. The adhesion molecules CD2, CD8, CD54, L-selectin, and CD49d (VLA-4 and LPAM-1 α-chain) were not expressed by all CTL hybridomas and therefore not indispensable for invasion in vitro and dissemination in vivo. In contrast, LFA-1 (CDlla/CD18), CD44, and VLA-6 (CD49f/CD29) were expressed on all hybrids. LFA-1 antibodies inhibited CTL hybridoma invasion in vitro, but antibodies inhibiting CD44-hyaluronate and VLA-6-laminin interaction had no effect. These results suggest that migration of cytotoxic T cells into non- inflamed tissues is independent of their activation state and does not require L-selectin, LPAM-1, CD2, and VLA-4. J. Leukoc. Biol. 53: 381–389; 1993.
Mechanisms of Kupffer cell cytotoxicity in vitro against the syngeneic murine colon adenocarcinoma line MCA26
Authors: Curley Steven A , Roh Mark S , Feig Barry , Oyedeji Caroline , Kleinerman Eugenie S , Kiostergaard Jim
Published: January 2018

We have previously demonstrated that in vivo activation or inhibition of Kupffer cell (KG) cytotoxic function can reduce or enhance, respectively, the hepatic tumor burden in a syngeneic murine colon adenocarcinoma (MCA26) tumor model. In the current study, we have performed in vitro experiments to define the possible mechanisms of KG cytotoxicity against MGA26 cells. Addition of either anti-tumor necrosis factor (TNF) or anti-interleukin-1α (IL-lα) antisera reduced KG cytotoxicity in coculture against MCA26 targets in a dose- dependent fashion; addition of these sera together resulted in approximately additive inhibition, suggesting the existence of parallel pathways for these effector molecules. Nitric oxide as a mediator of cytotoxicity by KCs in coculture with MCA26 cells was evaluated by two approaches. Activated KGs produced detectable levels of nitric oxide; however, activated KC exerted cytotoxicity against MCA26 targets in the absence of exogenous free L-arginine. Thus, TNF and IL-1 play major roles in producing murine KG cytotoxicity against MCA26 colon cancer cells in vitro, whereas reactive nitric oxides do not. J. Leukoc. Biol. 53: 715–721; 1993.
Suppression of human IgE antibody forming cell responses by IL-6
Authors: Kleiner Gary I , Auci Dominick L , Shaikh Altaf , Chice Soto M , Durkin Helen G
Published: January 2018

To study the effects of cytokines on human IgE antibody forming cells (AFCs), log phase U266 myeloma cells (3 × 103/ml), which secrete immunoglobulin E (IgE), were cultured for 0-24 h with and without cytokine or with or without antibodies against various cytokines. The numbers of IgE AFCs were determined in ELISPOT assay. We found that interleukin-6 (IL-6) suppressed (to 95%) whereas anti-IL-6 increased (to 148%) the numbers of IgE AFCs and that both worked in a dose- dependent fashion. IL-4 and interferon-γ (IFN-γ) also suppressed IgE AFC responses in a dose-dependent fashion. However, antibodies to these cytokines had no effect. In contrast, IFN-α increased (to fourfold) the numbers of IgE AFCs in a dose-dependent fashion. The data are the first to show a suppressive effect of IL-6 on human IgE responses and may also suggest a role for IL-6 in the treatment of atopic disease.
Particle-induced in vivo priming of alveolar macrophages for enhanced oxidative responses: a novel system of cellular immune augmentation
Authors: Myrvik Quentin N , Gristina Anthony G , Giridhar Girish , Hayakawa Hiroshi
Published: January 2018

A novel system for priming adult rabbit alveolar macrophages (AMs) in vivo for markedly enhanced oxidative responses is described. When adult rabbits were injected intravenously (i.v.) with 1- to 5-μm particles such as zymosan, latex particles, or heat-killed bacille Calmette-Guérin, AMs were primed in 1-3 days for greatly enhanced phorbol myristate acetate (PMA)- or opsonized zymosan (Op-zym)-elicited chemiluminescent (CL) responses. Intratracheal (i.t.) injection of zymosan particles also primed AMs for enhanced PMA- or Op- zym-elicited CL responses. AMs obtained from particle- injected rabbits showed up to 100-fold higher levels of PMA-elicited CL responses than AMs from normal rabbits. In contrast, Op-zym failed to prime normal AMs in vitro for enhanced CL responses. Whereas AMs could not be primed in vivo with an i.v. injection of particles of - 24 μm diameter, AMs could be primed if the particles were administered by the i.t. route. The priming appears to be independent of particle types. The priming effect was of short duration and declined after 5 to 7 days. The possibility that this system represents the primitive cellular immune response found in invertebrates is discussed. The potential use of this system as a means of immune augmentation prompts further investigation.
Enhanced hepatic clearance of intravenously administered sterically stabilized microspheres in zymosan-stimulated rats
Authors: Moghimi S M , Hedeman H , Christy N M , Ilium L , Davis S S
Published: January 2018

The blood clearance and organ deposition of sterically stabilized (poloxamine-908 coated) polystyrene microspheres of two different sizes (60 and 220 nm in diameter) were compared in control and zymosan- stimulated rats 3 h after intravenous administration. Poloxamine coating dramatically decreased the uptake of 60-nm microsphcres by organs of the reticuloendothelial system and, concomitantly, kept microspheres in the blood. Large poloxamine-coated microspheres (220 nm) initially remained in the blood, but eventually a large fraction of these microspheres was filtered by the spleen. Daily administration of zymosan produced a marked increase in the intravascular clearance of the large, but not the small, poloxamine-coated microspheres. The enhanced intravascular clearance of large poloxamine- coated microspheres in zymosan-treated rats was the result of hepatic sequestration. On the other hand, the splenic filtration of these microspheres was depressed by 225% below the control values, despite the dramatic increase in spleen size of zymosan-treated rats. Preincubation of large poloxamine-coated microspheres in serum derived from both the control and zymosan-treated animals suggested that the enhanced hepatic uptake of large sterically stabilized microspheres following zymosan stimulation was not the result of “specific opsonization” processes. Instead, the changes in the proliferative as well as the phagocytic response of Kupffer cells appeared to be responsible for these observations. The preferred hepatic uptake of large poloxamine-coated microspheres, as opposed to smaller particles, is suggested to be due to differences in surface characteristics and the properties of microspheres. These may include differences in polymer density and the surface conformation of the polyoxyethylene segments of the polymer in the biological environment and the way they interact with both plasma components and the macrophage surface. These observations could be of importance in the use of sterically stabilized drug carriers for delivery of therapeutic agents to sites other than the reticuloendothelial system in clinical conditions associated with globally or regionally enhanced reticuloendothelial activity.
Involvement of inflammatory mediators in macrophage antitumor activity
Authors: Bonta Ivan L , Ben-Efraim Shlomo
Published: January 2018

This review describes the potential role of macrophages in defense against cancer cells and the regulatory involvement of inflammatory mediators in this role. Interactions between macrophage-derived cytokines (tumor necrosis factor a, interleukin-1, IL-6) and their interrelationships with eicosanoids (mainly the cyclooxygenase product prostaglandin E2 and some lipoxygenase metabolites) represent a network that controls the expression of antitumor activity of macrophages either in a cell-to-cell contact system between the effector and the target tumor cell or as cell-free soluble products. Attention is given to the influence of tumor burden on production of cytokines and eicosanoids by macrophages and to the production of these mediators by tumor cells. Emphasis is placed on the roles of TNF-α and PGE2 in links between inflammatory and antitumor functions of macrophages. Finally, the perspectives and still existing problems in clinical implications of macrophage-derived cytokines are discussed in terms of a conceivable macrophage-directed immunotherapy of cancer.
The role of CD4+ and CD8+ T cells in the protective inflammatory response to a pulmonary cryptococcal infection
Authors: Huffnagle Gary B , Lipscomb Mary F , Lovchik Julie A , Hoag Kathleen A , Street Nancy E
Published: January 2018

Moderately virulent strains of Cryptococcusneoformans, inoculated via the trachea, cause a pulmonary infection in BALB/c mice that was gradually resolved by T lymphocyte-dependent mechanisms. The current studies, using monoclonal antibodies to deplete T cell subsets, demonstrated that CD4+ and CD8+ T cells combined to mediate a prominent pulmonary inflammatory infiltrate that included lymphocytes, macrophages, neutrophils, and eosinophils. The inflammatory response peaked 2 weeks after infection and coincided with the beginning of gradual pulmonary clearance of the infection. CD4/CD8 double, deficiency (4-8-) markedly reduced the influx of all cells into the lungs. A CD4 deficiency had a more profound effect on the total number of inflammatory cells recruited to the lungs than a CD8 deficiency. Depletion of either CD8+ or CD4+ T cells significantly decreased pulmonary macrophages and neutrophils, but only a CD4 deficiency prevented the influx of eosinophils. Recruitment of CD8+ T cells occurred independently of CD4+ T cells, but CD4+ T cell recruitment to the lungs was significantly reduced in CD8-deficient mice. Mitogen-stimulated infiltrating lung lymphocytes from infected 4+8+ mice secreted both T helper cell type 1 (Th1) [interferon-γ (IFN-γ) and interleukin-2 (IL-2)] and Th2 (IL-4, IL-5, and IL-10) cytokines. CD4 deficiency resulted in loss of T cells secreting IL-4, IL-5, and IL-10. However, residual CD8+ T cells still secreted IL-2 and IFN-γ. Lung T cells from CD8-deficient mice secreted similar levels of IL-4, IL-5, and IL-10 on a per lung basis compared with 4+8+ mice despite decreased numbers of CD4+ T cells, but secreted reduced levels of IFN-γ. These experiments indicate that (1) CD4+ T cells play a dominant role in recruiting macrophages and granulocytes to the lung and (2) CD8+ T cells also mediate cellular recruitment, increase the magnitude of CD4+ T cell numbers in the infiltrate, and contribute to the local secretion of IFN-γ. Thus, these studies demonstrate that CD8+ T cells can independently mediate an inflammatory response to a large, particulate, extracellular antigen, a role heretofore attributed almost solely to CD4+ T cells. J. Leukoc. Biol. 55: 35–42; 1994.
Interleukin-2 suppresses activated macrophage intracellular killing activity by inducing macrophages to secrete TGF-β
Authors: Nelson Barbara J , Danielpour David , Rossio Jeffrey L , Turpin Jim , Nacy Carol A
Published: January 2018

Phorbol myristate acetate (PMA) treatment of an EL-4 thymoma cell line (EL-4farrar) induced secretion of a factor that inhibited intracellular killing of Leishmania major amastigotes by activated macrophages. Analysis of the cytokines produced by EL-4 cells after PMA stimulation identified interleukin-2 (IL-2, 2500 U/ml), IL-4 (1280 U/ml), interferon-γ (IFN-γ; 100 U/ml), and granulocyte-macrophage colony-stimulating factor (GM-CSF; 50 U/ml). Neither tumor necrosis factor nor transforming growth factor β (TGF-β) was detected. Each of the cytokines present in EL-4 fluids was assessed for capacity to activate macrophages for destruction of parasites or to suppress intracellular killing. IFN-γ and GM-CSF both activated macrophages to kill Leishmania; I L-2 and IL-4 had no activity for induction of this anti-microbial effector function. IL-2 and IL-4 were tested for their capacity to inhibit lymphokine- or IFN-γ-induced destruction of L. major by macrophages: IL-4 was ineffective, but IL-2 markedly suppressed the activation of macrophages for intracellular killing. Addition of ≥ 10 U/ml of IL-2 at the time of infection, or up to 4 h before, blocked up to 100% of the capacity of activated macrophages to kill intracellular amastigotes. Immunoaffinity treatment of EL-4 fluids with anti-IL-2 antibody resulted in >80% reduction in suppression of intracellular killing. The suppressive effects of IL-2 were not direct, but mediated by TGF-β. IL-2 induced resident peritoneal macrophages to secrete >5000 pg/ml TGF-β1, a quantity that is > 500-fold higher than constitutive background levels (20–40 pg/ml) and is sufficient to block intracellular killing activities. This increase in secretion of TGF-β was not dependent increases in TGF-β1 mRNA. Treatment of cultures with EL-4 fluids or recombinant IL-2 in the presence of antibody to TGF-β1 blocked the suppressive activity of both. Thus, IL-2 was the major suppressor factor in EL-4 fluids, and it acted indirectly through the induction and autocrine action of TGF-β. J. Leukoc. Biol. 55: 81–90; 1994.
A single assay for measuring the rates of phagocytosis and bacterial killing by neutrophils
Authors: Hampton Mark B , Vissers Margret C M , Winterbourn Christine C
Published: January 2018

We have developed a method that enables the rates of phagocytosis and killing of bacteria by neutrophils to be measured in a single assay. Neutrophils were incubated with bacteria, and at specific intervals were separated from uningested bacteria by low speed centrifugation. Rates of phagocytosis and killing were calculated from the decrease in number of extracellular bacteria and change in the number of intracellular bacteria. Both phagocytosis and killing were shown to follow first-order kinetics, and rate constants were calculated without having to separate the assay into two phases. In contrast to two-step methods, our method measures killing from the moment the neutrophils start ingesting the bacteria, and also eliminates the need to halt neutrophil activity temporarily and restart the assay after the extracellular bacteria have been removed. We obtained reproducible results for the phagocytosis and killing of Staphylococcus aureus (t1/2 = 9 min and 6 min respectively) and Escherichia coli (t1/2 = 10 min and 2 min respectively). We also were able to detect a 56% impairment in the rate of killing of S. aureus by neutrophils from an individual with a low level of myeloperoxidase. J. Lcukoc. Biol. 55: 147–152; 1994.
Influence of interleukin-2 infusion on cell cycle kinetics in the Walker-256 carcinosarcoma
Authors: Wan Jennifer M -F , Bistrian Bruce R , Figoni Mary-Ann T , Istfan Nawfal W
Published: January 2018

The effect of recombinant human interleukin-2 (IL-2) on tumor cell cycle kinetics was evaluated in rats bearing the Walker-256 carcinosarcoma. Seven days after implantation, tumor-bearing rats were infused intravenously with IL-2 at a dose of 500 mg/kg body weight or 5% dextrose for 6 h. Tumor cell mean DNA synthesis time (Tdna), labeling index, potential doubling time (Tpot)) and growth fraction (GF) were determined in vivo by use of bromodeoxyuridine (BrdUrd) pulse labeling and bivariate BrdUrd/DNA analysis using flow cytometry. IL-2 treatment significantly reduced the relative number of S-phase cells by 11.9% and increased the number of cells in the G0/G1 phase by 9.4%. The labeling index was reduced from 41.3 ± 2.5% to 32.7 ± 1.2% (P <. 01). Estimates of TDNA derived from the change in BrdUrd movement relative to DNA content were not affected by IL-2 treatment. Based on these cytokinetic changes, IL-2 infusion significantly increased tumor Tpot from 15.3 ± 0.3 h to 21.5 ± 0.2 h (P < .001) and reduced GF from 1.01 ± 0.07 to 0.83 ± 0.01 (P < 0.001). The inhibitory effect of IL-2 infusion on tumor cell growth, which may be either direct or secondarily mediated by other factors, contrasts with other stimulatory effects of this cytokine on lymphoid cell proliferation. J. Leukoc. Biol. 55: 241–247; 1994.
Quantitative discrimination of hepatic reticuloendothelial clearance and phagocytic killing
Authors: Klein Andrew , Zhadkewich Michael , Margolick Joseph , Winkelstein Jerry , Bulkley Gregory
Published: January 2018

An in vivo assay to quantify simultaneously two important components of hepatic reticuloendothelial system (RES) function—clearance and phagocytic killing—was developed in the rat. Intravenously injected E. coli labeled with Na51Cr and 5-[123I]-iodo-2′-deoxyuridine were cleared rapidly from the blood primarily by the liver. While hepatic 51Cr levels remained stable for 24 h following inoculation and provided a reliable measurement of clearance, hepatic 125I decreased over time. Hepatic 125I, calculated by sampling whole liver homogenates, accurately reflects the number of viable bacteria recovered from quantitative cultures of the same homogenates, thus validating this assay as a measure of bacteria killing. Pre-treatment of rats with substances previously shown to affect RES function (gadolinium, zymosan, and sheep erythrocytes) were found to selectively modulate clearance and/or killing. The correlation between hepatic isotope levels and viable hepatic bacteria, the gold standard for assessing the capacity of the liver to remove organisms from the blood and kill them, was preserved under conditions of up- and down-regulation of RES function. The ability to quantitatively discriminate two distinct components of the hepatic RES should provide a useful tool for future investigations of altered RES function. J. Leukoc. Biol. 55: 248–252; 1994.
β
2-Adrenoceptor agonists regulate the IL-4-induced phenotypical changes and IgE-dependent functions in normal human monocytes
Authors: Paul-Eugène Nathalie , Kolb Jean Pierre , Damais Chantal , Abadie Annie , Mencia-Huerta Jean Michel , Braquet Pierre , Bousquet Jean , Dugas Bernard
Published: January 2018

The β  2-adrenoceptor agonists salbutamol and fenoterol were tested for their regulatory effects on human monocyte phenotype and functions, either alone or in combination with interleukin-4 (IL-4). These drugs enhanced in a dose-dependent manner the IL-4-induced membrane and mRNA expression of the low-affinity receptor for immunoglobulin E (IgE) (CD23), as well as the release of its soluble form, sCD23. Salbutamol and fenoterol alone elicited expression of the monomorphic β  2-chain (CD18) of the leukocyte functional antigen (LEA1) family. This effect appeared to be restricted to CD11b (CR3) and CD11c (gp 150–95), because CD11a (LFA-1α chain) was not modified, β  2-Adrenoceptor stimulation was also found to potentiate the effect of IL-4 on CD11b, CD11c, and CD18 expression. In contrast, these agents alone did not alter the level of major histocompatibility complex class II and CD14 antigens or modify their respective up- and down-regulation by IL-4. Ligation of CD23 on IL-4-preincubated (CD23*) monocytes with IgE/anti-IgE immune complexes induced the release of free radicals nitric oxide and of the proinflammatory mediators IL-6 and thromboxane B2 (TxB2). Addition of salbutamol, inactive alone, potentiated the generation of superoxide anion and of nitric oxide generation, as well as the production of IL-6 and TxB2 triggered by CD23 ligation. These results indicate that β  2-adrenoceptor stimulation potentiates in vitro the IL-4-induced phenotypical and functional changes on monocytes and suggest that such an interaction could occur in IgE-dependent immune reactions. J. Leukoc. Biol. 55: 313–320; 1994.
Differential RNA regulation by staphylococcal enterotoxins A and B in murine macrophages
Authors: Chapes Stephen K , Beharka Alison A , Hart Mark E , Smeltzer Mark S , Landolo J J
Published: January 2018

Staphylococcal enterotoxin A (SEA) is significantly better than enterotoxin B (SEB) in activating tumor necrosis factor (TNF) secretion by B6MP102 cells. Both toxins bound to B6MP102 cells; however, SEB competed less effectively with SEA than SEA competed with SEB. This suggested that receptors unique to SEA were present on B6MP102 cells. Signal transduction occurred in response to both toxins. Within 30 s after addition, SEA and SEB significantly increased the F-actin concentration in B6MP102 cells. However, only SEA induced increased TNF mRNA levels. B6MP102 cells incubated with interferon-γ and SEB secreted TNF. However, enhanced mRNA expression was delayed and the concentration of TNF secreted was less than that of B6MP102 cells stimulated with SEA. Although these data suggest that receptors unique to SEA are present on B6MP102 cells, they also indicate that staphylococcal enterotoxins differentially regulate TNF at the RNA level, perhaps because of differences in binding to the plasma membrane. J. Leukoc. Biol. 55: 523–529; 1994.
Expression and visualization during cell cycle progression of alkaline phosphatase in B lymphocytes from C3H/HeJ mice
Authors: Souvannavong Vongthip , Brown Spencer , Sarih M’hammed , Adam Arlette
Published: January 2018

The expression of alkaline phosphatase (APase) activity by purified B cells from lipopolysaccharide (LPS)-hyporesponsive C3H/HeJ mice was determined. Optimal APase activity was expressed after costimulation with interleukin-5 and dextran sulfate (DXS), whereas LPS, which is highly effective on B lymphocytes from normal mice, was unable to induce enzyme expression, even in the presence of DXS. The simultaneous determination by flow cytometry of both cellular APase, by using a fluorescent azo dye technique, and DNA content showed that APase was highly expressed by about one-tenth of cells in G1 phase, whereas it was present in more than 50% of cells in S and G2/M phases. The enzyme, as visualized by confocal microscopy after cell sorting on the basis of DNA content, was found to be, localized mainly in vesicular structures distributed throughout the cytoplasm in G1 cells. It was distributed in patches and essentially localized at the cell periphery in S cells, whereas clear capping of activity was observed in G2/M cells. J. Leukoc. Biol. 55: 626–632; 1994.
Generation of an ovine bone marrow-derived myelomonocyte-like cell line by retroviral-mediated transformation. Immunological characterization and the effect of cytokines and lipopolysaccharides
Authors: John Huw A , Deane David , Haig David
Published: January 2018

A cell line (designated BMpXTl) was generated from sheep bone marrow using the Moloney murine leukemia virus-based retroviral vector pXTl. BMpXTl cells resembled mature alveolar macrophages in being adherent and esterase positive, in expressing certain cell surface antigens, and in secreting granulocyte-macrophage colony-stimulating factor (GM-CSF) when stimulated by ovine interferon-γ and lipopolysaccharide (LPS) in combination. The absence of a proliferative response to ovine GM-CSF and macrophage colony-stimulating factor, the absence of other cell antigens found in mature macrophages, and lsw-efficiency phagocytosis suggested that the cells may be at an intermediate to late stage of myelomonocytic differentiation. J. Leukoc. Biol. 55: 785–792; 1994.
Role of macrophages in the immunotherapy of Lewis lung peritoneal carcinomatosis
Authors: Wallace Paul K , Morahan Page S
Published: January 2018

The underlying cellular mechanisms for the antitumor effects of biological response modifiers (BRMs) have not been clearly resolved. We have investigated this issue in the Lewis lung (3LL) peritoneal carcinomatosis model in which treatment with the BRM MVE-2 slows tumor growth and enhances survival. MVE-2 is a potent inducer of cytotoxic macrophages (mφs); however, the in vivo tumoricidal properties of these mφs remain to be firmly established. To directly establish that mφs were at least in part responsible for the in vivo efficacy of MVE-2, a novel method of obtaining highly enriched mφ suspensions was developed which gave high purity, satisfactory yield, and excellent viability without affecting antitumor activity. Using the 3LL peritoneal carcinomatosis model and adoptive transfer techniques, we directly demonstrate that the majority of antitumor activity was associated with the adherent cell fraction enriched for mφs. Histological observations supported this conclusion, indicating that MVE-2 treatment initially activated cells associated with nonspecific immunity, retarding tumor growth in the ascites long enough for a multifaceted immune response to develop. J. Leukoc. Biol. 56: 41–51; 1994.
Changes in subcellular localization and surface expression of L-selectin, alkaline phosphatase, and Mac-1 in human neutrophils during stimulation with inflammatory mediators
Authors: Borregaard Niels , Kieldsen Lars , Sengelo Henrik , Diamond Michael S , Springer Timothy A , Anderson H Clarke , Kishimoto Takashi K , Bainton Dorothy F
Published: January 2018

The localization of the adhesion protein L-selectin in human neutrophils was determined by sub-cellular fractionation and immunoelectron microscopy and compared with the localization of Mac-1 (α  m  β  z  ) and alkaline phosphatase, the marker for secretory vesicles. L-selectin was found to be localized exclusively on the plasma membrane of unstimulated cells and also of stimulated cells, although markedly diminished. This was in contrast to Mac-1, which was also localized in secretory vesicles and in specific/gelatinase granules as shown previously [Sengeiov, H., et al. J. Clin. Invest. (1993) 92, 1467–1476]. Stimulation of neutrophils with inflammatory mediators such as tumor necrosis factor (TNF), platelet-activating factor (PAF), or f-Met-Leu-Phe (fMLP), induced parallel up-regulation of the surface membrane content of alkaline phosphatase and Mac-1 and down-regulation of L-selectin, as evidenced by flow cytometry. Preimbedding immunoelectron microscopy confirmed that L-selectin was present mainly on tips of microvilli in unstimulated cells and showed that alkaline phosphatase and Mac-1 were randomly distributed on the surface membrane of fMLP-stimulated cells. These studies indicate that the transition of neutrophils from L-selectin-presenting cells to Mac-l-presenting cells induced by inflammatory mediators is mediated by incorporation of secretory vesicle membrane, rich in Mac-1 and devoid of L-selectin, into the plasma membrane. J. Leukoc. Biol. 56: 80–87; 1994.
HIV replication in chronically infected macrophages is not inhibited by the Tat inhibitors Ro-5-3335 and Ro-24-7429
Authors: Dunne Amanda L , Siregar Hanni , Mills John , Crowe Suzanne M
Published: January 2018

Human immunodeficiency virus infects different cell types including CD4+ lymphocytes and monocyte-derived macrophages (MDMs). We have examined the activity of the HIV-1 Tat inhibitors Ro-5-3335 and Ro-24-7429 in cultured human peripheral MDMs. Monocytes were isolated from HIV-seronegative donors by gradient centrifugation and plastic adherence. MDMs and unfractionated peripheral blood mononuclear cells (PBMCs) were infected with HIV Ba-L and then treated with drug either immediately (acute infection) or after 4 days (PBMCs) or 14 days (MDMs) (chronic infection). Inhibition of HIV replication by each drug was assessed by quantitation of HIV p24 antigen in culture supernatant using an enzyme immunoassay. In acutely infected MDMs, Ro-5-3335 (10 μM) and Ro-24-7429 (10 μM) resulted in 77% and 99% mean inhibition, respectively, of HIV replication with a clear dose response at lower concentrations; chronically infected MDMs were much less susceptible to these drugs, with both compounds inhibiting p24 antigen production by less than 50% at 10 μM. The drugs had no deleterious effect on cell viability at any concentration tested. In acutely infected PBMCs Ro-5-3335 and Ro-24-7429 resulted in 68% and 68.5% mean inhibition at 10 μM; when the compounds were added 4 days after infection inhibition was less than 50% compared with controls. Thus, the Tat inhibitors were effective in inhibiting acute HIV infection in MDMs but not in chronically infected cells, findings that differ from those of published studies using continuous lymphoblastoid cell lines. J. Leukoc. Biol. 56: 369–373; 1994.