bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cathepsin G binds to human lymphocytes
Authors: Yamazaki Tomomi , Aoki Yosuke 
Published: January 2018

Abstract
Cathepsin G is a serine protease located in the azurophil granules of neutrophils. We have shown previously that cathepsin G stimulates human lymphocytes. In this study, we demonstrate that cathepsin G exhibits specific, saturable and reversible binding to lymphocytes: B cells, CD4+ T cells, CD8+ T cells, and natural killer (NK) cells. Phenylmethylsulfonyl fluoride (PMSF) -inhibited cathepsin G also bound to lymphocytes, although both the number of binding sites and the affinity were less than those of native cathepsin G. The binding of cathepsin G to lymphocytes showed cooperativity, but that of PMSF-inhibited cathepsin G did not. PMSF-inhibited cathepsin G was able to partially displace bound cathepsin G. These results suggest that molecules on the lymphocyte surface that bind cathepsin G recognize not only the active site of cathepsin G but also other sites of this molecule, but the active site has an important function in this binding because stimulation of lymphocytes requires the binding of proteolytically active cathepsin G.
Expression of the human NRAMP1 gene in professional primary phagocytes: studies in blood cells and in HL-60 promyelocytic leukemia
Authors: Cellier Mathieu , Shustik Chaim , Dalton William , Rich Elizabeth , Hu Jinxin , Malo Danielle , Schurr Erwin , Gros Philippe 
Published: January 2018

Abstract
In the mouse, mutations at the natural resistance-associated macrophage protein 1 (Nrampl) gene abrogate resistance to infection with antigenically unrelated intracellular parasites such as Mycobacterium, Salmonella, and Leishmania. Nrampl expression is restricted to reticuloendothelial organs and peripheral blood leukocytes, where the protein may function as a membrane transporter of an as yet to be identified substrate. To identify the human blood cell type(s) expressing NRAMPl mRNA and determine how Nrampl expression is regulated in these cells, we have examined separated populations of peripheral blood leukocytes and in vitro cell lines. We observed that polymorphonuclear leukocytes (PMN) are the major site of NRAMP1 expression, followed to a lesser degree by monocytes (MN). Migration of MN to tissues (alveolar macrophages) or maturation in vitro (long-term culture) was associated with a higher level of NRAMP1 expression compared with blood MN. Northern analyses of RNA from model cultured cells showed absence of NRAMP1 expression in transformed cell lines from either erythroid or lymphoid T or B lineages as well as progenitors of the monocyte/macrophage pathway (KG1, U937, THP1), and the HL-60 promyelocytic leukemia. Induction of differentiation of HL-60 cells toward either the monocyte/ macrophage (vitamin D3, phorbol ester) or the granulocyte pathways (DMF, DMSO), as measured by induction of IL8-Rb, c-FMS, and CD14 marker gene expression, was concomitant with a strong induction of NRAMP1 expression. These results suggest that NRAMP1 expression is specific to the myeloid lineage and is acquired during the maturation of PMN and MN. The possibility that NRAMP1 may be a component of the phagosomal/endosomal apparatus common to PMN and MN is discussed.
Regulation of cytokine expression in macrophages and the Langerhans cell-like line XS52 by calcitonin gene-related peptide
Authors: Torii Hideshi , Hosoi Junichi , Beissert Stefan , Xu Shan , Fox Floyd E , Asahina Akihiko , Takashima Akira , Rook Alain H , Granstein Richard D 
Published: January 2018

Abstract
Calcitonin gene-related peptide (CGRP) inhibits antigen presentation by Langerhans cells (LC) and macrophages, and LC are anatomically associated with CGRP-containing epidermal nerves. To determine whether CGRP may produce some of its functional effects through regulation of cytokine expression, we utilized enzyme-linked immunosorbent assay (ELISA) of conditioned supernatants to examine production of interleukin (IL)-10 and IL-1β protein in the LC-like cell line XS52 as well as the reverse transcriptase-polymerase chain reaction (RT-PCR) to examine levels of mRNA for IL-10, IL-1β, and the 40-kDa subunit (p40) of IL-12. CGRP augmented the lipopotysaccharide (LPS) and granulocyte-macrophage colony-stimulating factor (GM-CSF) -induced release of IL-10 protein and the induced expression of IL-10 mRNA in these cells. However, it suppressed the induction of release of IL-1β protein and the induction of mRNA for IL-12 p40 and IL-1β by LPS and GM-CSF. Regulation of cytokine expression in peritoneal macrophages was also examined. By ELISA, the LPS-induced expression of IL-10 was augmented by CGRP, whereas the induction of IL-1β was suppressed. Northern analysis demonstrated augmentation of LPS-induced IL-10 mRNA levels and inhibition of LPS-induced IL-1β mRNA by CGRP. CGRP inhibited the LPS-induced induction of IL-12 mRNA as assessed by RT-PCR. Up-regulation of B7-2 expression by LPS and GM-CSF was suppressed by CGRP in both XS52 cells and macrophages, as previously reported. This suppression, however, could be abrogated by co-culture with neutralizing antibodies to IL-10. Furthermore, the presence of neutralizing antibodies to IL-10 during exposure of epidermal cells (EC) to CGRP prevented the CGRP-mediated suppression of EC presentation of tumor-associated antigens (from the S1509a spindle cell carcinoma) for elicitation of delayed-type hypersensitivity in S1509a-immune mice. These data suggest that suppression of antigen-presenting function by CGRP is mediated, at least in part, by changes in cytokine expression that favor less robust antigen presentation for cell-mediated immunity.
Immunosuppressive retroviral peptides: Immunopathological implications for immunosuppressive influences of retroviral infections
Authors: Haraguchi Soichi , Good Robert A , Cianciolo George J , Engelman Robert W , Day Noorbibi K 
Published: January 2018

Abstract
Studies of the effects of retroviruses on the immune system, which date back through thirty years of investigations, are reviewed. In the earliest published studies in the 1960s, it was demonstrated that mice infected with oncogenic viruses were immunosuppressed. Since then, numerous articles have been published describing profound immunodeficiencies observed in vivo in humans infected with human immunodeficiency virus and in animals such as cats infected with the feline immunodeficiency virus. In vitro investigations have shown that inactivated retroviruses or transmembrane envelope protein pl5E as well as a synthetic 17-amino acid peptide (CKS-17) impressively conserved within the transmembrane envelope protein of several animal or human retroviruses are highly immunosuppressive. More recently, dysfunction of cytokines produced by CKS-17 at both a cellular and molecular level have been found to mimic influences observed in vivo in patients infected with the human immunodeficiency virus. CKS-17 has also been shown to induce cAMP in vitro. The significance of these observations to understanding the immunological disturbances observed in malignancy, cytokine biosynthesis, and modulations of immune functions through cAMP is discussed.
IL-13 acts on macrophages to block the completion of reverse transcription, inhibit virus production, and reduce virus infectivity
Authors: Montaner Luis J , Bailer Robert T , Gordon Siamon 
Published: January 2018

Abstract
An understanding of the immune suppression of HIV-1 replication in macrophages continues to be a major goal of AIDS research due to the central role this cell type has in AIDS pathogenesis. We have previously discussed the potential clinical benefits of the anti-inflammatory cytokine interleukin-13 (IL-13), which, unlike IL-4 or IL-10, has limited effects on T cell functions. In this report we extend our observations on the effects of IL-13 on HIV-1 replication in monocyte-derived macrophages (MDM) and show redundancy with IL-4. IL-13 or IL-4 have similar effects on HIV-1 replication in MDM when added at different times after infection, with the ability to decrease infectious virus release when added for up to 7 days after infection. Removal of IL-13 from MDM revealed a reduction of infection by 16- to 81-fold based on the absence of viral re-emergence from lower multiplicity of infection (m.o.i.). The reduction of HIV-1 infectivity in MDM caused by IL-13 was further characterized by studies on the formation of viral DNA over a range of m.o.i. IL-13 increased the formation of LTR DNA at the lowest m.o.i. of 0.007 while concurrently inhibiting the formation of gag DNA, a later reverse transcription product, at the highest m.o.i. tested, 0.62. Overall, our data indicate that IL-13 can act on macrophages before and after HIV-1 infection by blocking the completion of reverse transcription, decreasing virus production, and reducing the infectivity of the progeny virions.
Macrophage tropism: fact or fiction?
Authors: Stent Gianna , Joø Gun-Britt , Kierulf Peter , Åsjö Birgitta 
Published: January 2018

Abstract
Primary HIV-1 isolates can be distinguished by phenotypic qualities such as the ability to productively infect cells of established CD4-positive lines and to induce syncytia in MT-2 cells. Such viral phenotypes have also been reported to confer host cell specificity. It is perceived that primary isolates with the syncytium-inducing phenotype (SI or rapid/high) are T cell tropic and are therefore unable to infect primary cells of the monocyte/macrophage lineage. However, we have consistently found that these isolates are as capable of establishing infection in monocyte-derived macrophages (MDM) as the monocytotropic, non-syncytium-inducing variants (NSI or slow/low). It is known that differentiation, activation, and proliferation of human monocytes are affected by both isolation methods and culture conditions. Therefore, to test whether our inability to discriminate macrophage tropic HIV-1 isolates could be explained by differences in culturing techniques, we isolated monocytes by elutriation or short-term adherence and allowed the cells to mature and differentiate in either the presence or absence of autologous lymphocytes. After removal of nonadherent cells, MDM were infected with a panel of SI and NSI primary HIV-1 isolates. MDM were susceptible to infection by the SI as well as the NSI isolates, regardless of whether or not the cells were allowed to mature in the presence of autologous lymphocytes. However, MDM matured in the presence of autologous lymphocytes replicated HIV-1 isolates (both NSI and SI) to a higher titre than MDM matured in the absence of lymphocytes. In light of these findings and recently published reports on HIV-1 phenotype and chemokine receptor usage we believe that the term macrophage-tropic strains of HIV-1 is no longer appropriate.
Mechanisms of loss of functional dendritic cells in HIV-1 infection
Authors: Knight Stella C , Elsley William , Wang Hong 
Published: January 2018

Abstract
Dendritic cells (DC) are lost from blood and skin during infection with HIV-1; those remaining show a reduced capacity to stimulate T cell proliferation [S. C. Knight, AIDS 10, 807–817]. Our recent studies investigate mechanisms underlying these effects. DC exposed to HIV-1 in vitro can act as targets for cytotoxic T cells, although optimal killing was not obtained until DC were exposed to HIV-1 for 3 days. This cytotoxicity may provide a feedback mechanism by which DC that have presented antigens are removed. However, this effect could also contribute to the reduction in DC during persistent infection. We have also investigated the effect of exposure to HIV-1 on DC function. DC exposed to HIV-1IIIB virus for 2 h stimulated primary proliferative and cytotoxic T cell responses in vitro; these effects may be similar to those occurring during the early activation of protective antiviral immunity in vivo. After exposure of DC to virus for 5 days, stimulation of allogeneic T cells was reduced. However, a different situation applied when using DC developed from CD34+ cord blood stem cells under the influence of granulocyte-macrophage colony-stimulating factor and tumor necrosis factor a that were exposed at 24 h to the same virus. These DC showed low levels of infection similar to peripheral blood DC but in contrast stimulated normal allogeneic T cell proliferation. The capacity of DC exposed to HIV-1 to stimulate T cell proliferation or to show a blocked stimulatory capacity may thus depend not only on the length of the exposure to virus but also on the maturational state of the DC. Loss in DC numbers and function on exposure to HIV-1 may result in lower levels of stimulation of T cells, which in turn may be instrumental in reduction of T cell numbers.
HIV-1 viral protein R (Vpr) regulates viral replication and cellular proliferation in T cells and monocytoid cells in vitro
Authors: Ayyavoo Velpandi , Mahalingam S , Rafaeli Yosef , Kudchodkar Sagar , Chang David , Nagashunmugam T , Williams William V , Weiner David B 
Published: January 2018

Abstract
Among the putative accessory genes of HIV-1, the 96-amino-acid virion-associated vpr gene product has been described to have several novel biological activities. These include cytoplasmic-to-nuclear translocation, which empowers HIV to infect and replicate in non-dividing cells and to increase viral replication, particularly in macrophages. Along with these viral effects, we found that HIV-1 Vpr induces dramatic biological changes in the target cells of HIV infection, including induction of changes in transcriptional patterns, morphological changes, and complete inhibition of proliferation, which collectively was termed differentiation. These changes occur in the absence of other viral gene products, suggesting that Vpr mediates its proviral effects partially or perhaps solely through modulation of the state of the target cell rather than directly on the virus. The inhibition of proliferation in T cell lines has been extended by several groups to demonstrate that the inhibition of proliferation is through G2 cell cycle arrest, further supporting the idea that Vpr acts directly on cellular targets. We have recently described a role for Vpr in modulating the glucocorticoid pathway, which is involved in the regulation of the state of the cell, in cytoplasmic-to-nuclear translocation, and in modulation of host cell transcription. It is important to note that certain anti-glucocorticoid compounds modulate Vpr activity in vitro. These results support the idea that the host cell contains specific receptor molecule(s) through which Vpr mediates its activity. Consequently, Vpr represents a unique target for anti-HIV drug development and has significance for HIV-1 disease progression.
Tumor site-selective localization of an adoptively transferred T cell line expressing a macrophage lectin
Authors: Ichii Shinji , Imai Yasuyuki , Irimura Tatsuro 
Published: January 2018

Abstract
CTLL-2 cells were transfected with an expression vector that contained cDNA of a mouse macrophage galactose/N-acetylgalactosamine-specific calcium-type lectin (MMGL) and a stable transfectant (CTL-ML) was established. These cells and mock transfectant cells (CTL-CEP) were labeled with a long-term fluorescent cell tracer, DiI. The labeled cells were intravenously injected into mice that contained established lung metastases produced by OV2944-HM-1 ovarian tumor cells. Analyses with fluorescence microscopy of a series of frozen lung sections from the recipient mice revealed that CTL-ML preferentially accumulated in the lung metastatic nodules, whereas CTL-CEP did not Time course studies showed that the preferential accumulation was evident 3 days after adoptive transfer. We also found that OV2944-HM-1 cells bound peanut agglutinin and Vicia villosaagglutinin B4, whose sugar specificity overlaps with the specificity of MMGL. These results suggested that MMGL molecules expressed on CTLL-2 cells contributed to their selective trafficking or retention in tumor foci possibly through recognition of tumor-associated cell surface carbohydrate antigens. These results also suggested that MMGL could be used for the selective targeting of effector cells in adoptive immunotherapy.
Menstrual- and gender-dependent variations in circulating IL-1 agonists, antagonists, and binding proteins
Authors: Cannon Joseph G , Abad Leslie W , Vannier Edouard , Lynch Elizabeth A 
Published: January 2018

Abstract
This study tested the hypotheses that sex-related differences in circulating binding proteins for interleukin-1 β (IL-1 β) exist and that these binding proteins affect immunoassays for IL-1 β and IL-1Ra. 125I-labeled IL-1 β was added to human plasma samples, then chromatographed. The percentages of total radioactivity eluting in a high-molecular-weight peak were 21.0 + 0.8 for men (n = 6), 19.1 ± 0.9 for follicular phase women (n = 6), and 18.0 ± 0.8 in luteal phase women (n = 6; men vs. women, P = 0.032; follicular vs. luteal, P = 0.035), and correlated with plasma sIL-1RII concentrations (r = 0.647, P = 0.007). Plasma IL-1 β immunoreactivity did not correspond to concurrent cellular secretion rates due, in part, to interference in the IL-1 β assay by sIL-1RII. Correspondence between plasma IL-1Ra levels and cellular secretion rates was observed only after serial dilutions of the samples. These results indicate that plasma IL-1 β binding capacity differs between men and women and that sIL-1RII is a major contributing factor. Furthermore, relating plasma IL-1 isoform immunoreactivity to functional measures (tracer binding) or concurrent release by isolated cells can lead to insights about assay interferences that may exist in plasma.
Nω-nitro-L-arginine methyl ester inhibits inflammatory liver injury induced by interleukin-2
Authors: Lentsch Alex B , Edwards Michael J , Sims David E , Miller Frederick N 
Published: January 2018

Abstract
Administration of interleukin-2 (IL-2) for treatment of metastatic disease often results in inflammatory liver injury. Previous studies have implicated increased leukocyte and platelet adhesion and enhanced nitric oxide production as causative factors in the development of IL-2-induced hepatic injury. This study investigated the capacity of Nω-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthesis inhibitor, to limit IL-2-induced hepatic edema and hepatocellular damage in mice. Using hepatic intravital microscopy, we also examined the effects of L-NAME on IL-2-induced increases in leukocyte and platelet adhesion. Administration of IL-2 increased leukocyte and platelet adhesion in postsinusoidal venules and decreased hepatic perfusion. Cotreatment with L-NAME had no effect on leukocyte adhesion but increased platelet-endothelial adhesion and microvascular thrombosis. Chronic IL-2 treatment induced hepatic edema and hepatocellular injury. However, coadministration of L-NAME attenuated IL-2-induced edema and completely inhibited hepatocellular damage. These findings suggest that nitric oxide may play a central role in IL-2-induced inflammatory liver injury.
Oxidant inhibition of αLβ2 integrin adhesion: evidence for coordinate effects on conformation and cytoskeleton linkage
Authors: Edwards Bruce S , Southon Eileen A , Curry Mark S , Salazar Francisco , Gale James M , Robinson Martyn K , Graf Lloyd H , Born Jerry L 
Published: January 2018

Abstract
Dithiothreitol (DTT) and other dithiol antioxidants with closely spaced thiol pairs strongly activate leukocyte function antigen-1 (LFA-1, αLβ2 integrin) to bind intercellular adhesion molecule-1 (ICAM-1). Because direct biochemical modification of LFA-1 by DTT is not apparently involved, we investigated the possible role of a reduction-oxidation (redox)-sensitive adhesion-regulatory pathway. Phenylarsine oxide (PAO), an oxidant selectively reactive with closely spaced pairs of thiol groups, inhibited LFA-1-dependent adhesion of human natural killer and HSB2 T leukemia cells to murine cells expressing human ICAM-1. PAO also induced disappearance of a conformation-sensitive LFA-1 epitope recognized by KIM127 antibodies and promoted an increase in total apparent cytoskeleton-linked LFA-1 in which a novel cytochalasin D-resistant linkage was involved. Exposure of PAO-pretreated cells to DTT caused a decline in LFA-1/cytoskeleton linkages in conjunction with rapid restoration of KIM127 epitope expression and LFA-1 adhesive function. Implicating an intracellular site of action were findings that (1) an epitope-tagged PAO probe bound predominantly to intracellular proteins but not detectably to immunoprecipitation-purified LFA-1 chains, and (2) membrane permeant but not impermeant dithiol antioxidants reversed PAO adhesion-inhibitory effects. These results support the concept of a reversible redox-sensitive linkage between LFA-1 and cytoskeleton by which oxidants and antioxidants may exert profound opposing effects on LFA-1 conformation and adhesive function.
Collagenase expression by normal human eosinophils
Authors: Shlopov Boris V , Hasty Karen A 
Published: January 2018

Abstract
Collagenolytic activity was detected in extracts from human blood eosinophilic granulocytes. To characterize this collagenase, we compared extracts from isolated populations of eosinophils and neutrophils. Significant collagenase activity against type I and II collagens was present in extracts from both cell populations. Although collagenase activity was present in eosinophils, the cells did not stain with antibodies specific for fibroblast, neutrophil collagenase, or collagenase-3. In contrast, neutrophils immunostained positively with antibody to neutrophil collagenase. Western blot analysis confirmed the presence of immunoreactive protein in neutrophil extracts but not in the eosinophil extracts. Reverse transcription-polymerase chain reaction using primers specific for all three known collagenases of an eosinophil cell suspension from peripheral blood that had 3% contamination with immature neutrophils showed a polymerase chain reaction product only with neutrophil collagenase oligonucleotide primers, but not with fibroblast collagenase or collagenase-3 primers. Eosinophil collagenase would appear to have a unique antigenic structure and may represent a new enzyme.
Modulation of neutrophil adherence to endothelial cells by platelet-derived adherence-inhibiting factor through interactions with selectin molecules
Authors: Iwabuchi Kazuhisa , Nagaoka Isao , Yamashita Tatsuhisa 
Published: January 2018

Abstract
Platelet-derived adherence-inhibiting factor (AIF) has been demonstrated to regulate the neutrophil binding to type IV collagen. In this study, we have examined the effect of AIF on neutrophil adherence to confluently cultured human umbilical vein endothelial cells (EC). AIF inhibited neutrophil adherence to thrombin- or tumor necrosis factor α (TNF-α)-stimulated EC by 75 or 43%, respectively, but hardly affected neutrophil adherence to resting EC. It is interesting to note that the inhibitory activity of AIF was reduced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) stimulation of neutrophils. Pretreatment of neutrophils or EC with AIF inhibited neutrophil adherence to thrombin- or TNF-α-stimulated EC, suggesting that neutrophils and EC have AIF-binding proteins. Using AIF-Sepharose affinity chromatography, AIF-binding proteins containing L-selectin were isolated from 125I-labeled resting neutrophils. However, L-selectin was markedly decreased in the AIF-binding fraction from fMLP-stimulated neutrophils. With the use of AIF-affinity chromatography, P- and E-selectins were obtained in the AIF-binding fractions from resting, thrombin-, and TNF-α-stimulated EC. It is important to note that P- and E-selectin were greatly increased in the AIF-binding fractions from thrombin- and TNF-α-stimulated EC, respectively. Furthermore, AIF was able to bind to L-selectin-IgG chimeric protein and inhibit the binding of chimeric protein to thrombin- or TNF-α-stimulated EC. In addition, AIF inhibited the binding of anti-P- or anti-E-selectin monoclonal antibody to the lysates of thrombin- or TNF-α-stimulated EC. Together these observations indicate that AIF could recognize L-, P-, and E-selectins, and modulate neutrophil adherence to EC through interactions with selectin molecules.