bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clearance of apoptotic cells: TGF-β in the balance between inflammation and fibrosis
Authors: Clancy Robert M , Buyon Jill P 
Published: September 2003

AbstractTransforming growth factor-β (TGF-β) has been considered an anti-inflammatory cytokine responsible for the bland removal of apoptotic cells. What is less established is the extent of secretion of this cytokine during the clearance of opsonized apoptotic cells via Fcγ-mediated uptake. To date both decreased (favoring predominance of inflammation) and increased (favoring resolution of inflammation but potentially pro-fibrotic) responses have been demonstrated. In an in vitro model of autoantibody-induced cardiac injury, we herein demonstrate that macrophages cocultured with apoptotic human fetal cardiocytes bound by anti-SSA/Ro antibodies secrete increased levels of TGF-β. Prolonged secretion of this cytokine may contribute to the exuberant scarring seen in congenital heart block associated with maternal autoantibodies reactive with SSA/Ro and SSB/La antigens.
HIV and cells of macrophage/dendritic lineage and other non-T cell reservoirs: new answers yield new questions
Authors: Collman Ronald G , Perno Carlo-Federico , Crowe Suzanne M , Stevenson Mario , Montaner Luis J 
Published: September 2003

AbstractDefining how human immunodeficiency virus (HIV) interacts with macrophages, dendritic cells (DC), and other non-T cell reservoirs remains a critical area of research despite widespread use in the developed world of highly active antiretroviral therapy. In fact, as highlighted at the Fifth International Workshop on HIV and Cells of Macrophage/Dendritic Lineage and Other Reservoirs, as viral suppression in T cells becomes increasingly effective, these alternative reservoirs may take on even greater relative importance as sites for viral persistence and as a target for purging. These cells may be especially important reservoirs in several critical settings of clinical relevance, and there are major differences in the molecular mechanisms that regulate HIV replication in these cells compared with T cells. Dysfunction of these cells may also play a major role in particular aspects of pathogenesis. Three broad themes emerged from the workshop regarding areas of recent progress, which also serve to identify current research challenges of (i) determining the role played by macrophages, DC, and other non-T cell viral targets in transmission and dissemination and as viral reservoirs at various stages of disease and in different compartments in vivo; (ii) identifying the molecular mechanisms by which virus–cell interactions affect the inflammatory, immune, and other functions of these cells; and (iii) defining the unique pathways that regulate infection and replication in these cellular compartments. This issue of JLB contains several reviews and original reports resulting from the workshop that address recent progress and highlight the current research questions regarding these cell types.
Phosphatidylserine expression and phagocytosis of apoptotic thymocytes during differentiation of monocytic cells
Authors: Callahan Melissa K , Halleck Margaret S , Krahling Stephen , Henderson Andrew J , Williamson Patrick , Schlegel Robert A 
Published: September 2003

AbstractExpression of phosphatidylserine (PS) on the surface of both macrophages and their apoptotic targets is required for efficient phagocytosis. Monocytes, the precursors of macrophages, do not express PS on their surface and do not efficiently phagocytose apoptotic cells. We report here that PS appears on the surface of both human monocytic U937 cells and primary human monocytes as they differentiate in culture and acquire the ability to phagocytose apoptotic thymocytes. Phagocytosis was blocked by pretreating either the apoptotic target or the phagocyte with annexin V to mask PS and was CD14-dependent. Expression of PS, like other events characteristic of differentiating monocytes such as Mac-1 expression, was independent of the agent used to induce differentiation and was insensitive to the addition of caspase inhibitors. These results demonstrate that PS is expressed on monocytes as part of their differentiation program and is independent of apoptosis.
Different antigens trigger different Th1/Th2 reactions in neonatal mononuclear cells (MNCs) relating to T-bet/GATA-3 expression
Authors: Yu Hong-Ren , Chang Jen-Chieh , Chen Rong-Fu , Chuang Hau , Hong Kuo-ching , Wang Lin , Yang Kuender D 
Published: September 2003

AbstractNeonates are known to have poor cellular immunity, especially poor Th1 response. We investigated how neonatal mononuclear cells raised different Th1/Th2 reactions in response to different antigens. Employing Dermatophagoides pteronyssinus (Der p) extract and varicella zoster virus (VZV) as antigens, we assessed Th1/Th2 reactions as demonstrated by IL-4/IFNγ production and mRNA expression, and transcriptional factors T-bet/GATA-3 mRNA expression in mononuclear cells from human umbilical cord blood (CBMC). Results showed that VZV induced a dramatic increase of IFNγ production by adult peripheral blood mononuclear cells (PBMC), whereas VZV did not drive CBMC to release significant IFNγ production (1614.7±362.0 vs. 49.0±29.3,p&lt;0.005). However, Der p induced higher IFNγ production by CBMC than VZV (298.1±171.8 vs. 49.0±29.3, P=0.047). In contrast, VZV did not induce significant IL-4 production either by CBMC or by PBMC. Der p induced a comparative IL-4 production by CBMC and PBMC (2.58±0.84 vs. 2.04±0.37, p&gt;0.05). A real-time RT-PCR analysis of IL-4 and IFNγ mRNA expression showed that VZV induced a significantly higher IFNγ, but not IL-4, mRNA expression in PBMC than CBMC. Der p did not induce significant difference of IFNγ or IL-4 mRNA expression in PBMC and CBMC. VZV enhanced Th1-related transcription factor T-bet mRNA expression, in association with later down-regulation of Th2-related GATA-3 mRNA expression in PBMC. However, VZV did not up-regulate T-bet or down-regulate GATA-3 expression significantly in CBMC. In contrast, Der p induced an early GATA-3 expression and later T-bet expression in CBMC. These results suggest that different antigens trigger various Th1/Th2 reactions in PBMC and CBMC resulting from kinetic changes of T-bet/GATA-3 expression.
Activation of Rac2 and Cdc42 on Fc and complement receptor ligation in human neutrophils
Authors: Forsberg Maria , Druid Pia , Zheng Limin , Stendahl Olle , Särndahl Eva 
Published: September 2003

Abstract
Phagocytosis is a complex process engaging a concerted action of signal-transduction cascades that leads to ingestion, subsequent phagolysosome fusion, and oxidative activation. We have previously shown that in human neutrophils, C3bi-mediated phagocytosis elicits a significant oxidative response, suggesting that activation of the small GTPase Rac is involved in this process. This is contradictory to macrophages, where only Fc receptor for immunoglobulin G (FcγR)-mediated activation is Rac-dependent. The present study shows that engagement of the complement receptor 3 (CR3) and FcγR and CR3- and FcγR-mediated phagocytosis activates Rac, as well as Cdc42. Furthermore, following receptor-engagement of the CR3 or FcγRs, a downstream target of these small GTPases, p21-activated kinase, becomes phosphorylated, and Rac2 is translocated to the membrane fraction. Using the methyltransferase inhibitors N-acetyl-S-farnesyl-L-cysteine and N-acetyl-S-geranylgeranyl-L-cysteine, we found that the phagocytic uptake of bacteria was not Rac2- or Cdc42-dependent, whereas the oxidative activation was decreased. In conclusion, our results indicate that in neutrophils, Rac2 and Cdc42 are involved in FcR- and CR3-induced activation and for properly functioning signal transduction involved in the generation of oxygen radicals.
The relative activity of CXCR3 and CCR5 ligands in T lymphocyte migration: concordant and disparate activities in vitro and in vivo
Authors: Stanford Marianne M , Issekutz Thomas B 
Published: September 2003

AbstractIn chronic inflammatory reactions such as rheumatoid arthritis and multiple sclerosis, T cells in the inflamed tissue express the chemokine receptors CXCR3 and CCR5, and the chemokine ligands (CCL) of these receptors are present in the inflammatory lesions. However, the contribution of these chemokines to T cell recruitment to sites of inflammation is unclear. In addition, the relative roles of the chemokines that bind CXCR3 (CXCL9, CXCL10, CXCL11) and CCR5 (CCL3, CCL4, CCL5) in this process are unknown. The in vitro chemotaxis and in vivo migration of antigen-activated T lymphoblasts and unactivated spleen T cells to chemokines were examined. T lymphoblasts migrated in vitro to CXCR3 ligands with a relative potency of CXCL10 &gt; CXCL11 &gt; CXCL9, but these cells demonstrated much less chemotaxis to the CCR5 ligands. In vivo, T lymphocytes were recruited in large numbers with rapid kinetics to skin sites injected with CXCL10 and CCL5 and less to CCL3, CCL4, CXCL9, and CXCL11. The combination of CCL5 with CXCL10 but not the other chemokines markedly increased recruitment. Coinjection of interferon-γ, tumor necrosis factor α, and interleukin-1α to up-regulate endothelial cell adhesion molecule expression with CXCL10 or CCL5 induced an additive increase in lymphoblast migration. Thus, CXCR3 ligands are more chemotactic than CCR5 ligands in vitro; however, in vivo, CXCL10 and CCL5 have comparable T cell-recruiting activities to cutaneous sites and are more potent than the other CXCR3 and CCR5 chemokines. Therefore, in vitro chemotaxis induced by these chemokines is not necessarily predictive of their in vivo lymphocyte-recruiting activity.
Predominance of Th2-promoting dendritic cells in early human pregnancy decidua
Authors: Miyazaki Satomi , Tsuda Hiroshi , Sakai Masatoshi , Hori Shinichi , Sasaki Yasushi , Futatani Takeshi , Miyawaki Toshio , Saito Shigeru 
Published: September 2003

Abstract
Dendritic cells (DCs) are specialized antigen-presenting cells required for the priming and activation of T cells and promote the differentiation of naïve CD4+ T cells toward the T helper cell type 1 (Th1) or Th2 phenotype. Here, we describe the characterization of CD45+CD3−CD14−CD16−CD19−CD20−CD56−HLA-DRbright DCs from early human pregnancy decidua by flow cytometry. The percentage of DCs to mononuclear cells (leukocytes) in the decidua was significantly higher than that in the peripheral blood. Moreover, decidual DCs expressed costimulatory molecules such as CD80 and CD86 and a mature marker such as CD83 on their surface. The percentage of CD11c+CD123− myeloid DCs in the decidua was significantly higher than that in the peripheral blood. Conversely, the ratio of CD11c−CD123+ lymphoid DCs in the decidua was significantly lower than that in the peripheral blood. The number of interleukin (IL)-12-producing cells in the total DC population and the myeloid DCs in the decidua was significantly lower than that in the peripheral blood. IL-12 secretion by activated decidual myeloid DCs was significantly lower than that by peripheral DCs. Naïve CD4+ T cells primed with decidual myeloid DCs led to a higher percentage of Th2 cells in comparison with that with peripheral myeloid DCs. This finding was abolished by exogenous IL-12 administration with decidual myeloid DCs. Thus, the DCs in the decidua could regulate the Th1/Th2 balance to maintain a Th2-dominant state, leading to maintenance of pregnancy.
Differential effects of invasion by and phagocytosis of Salmonella typhimurium on apoptosis in human macrophages: potential role of Rho–GTPases and Akt
Authors: Forsberg Maria , Blomgran Robert , Lerm Maria , Särndahl Eva , Sebti Said M , Hamilton Andrew , Stendahl Olle , Zheng Limin 
Published: September 2003

Abstract
In addition to direct activation of caspase-1 and induction of apoptosis by SipB, invasive Salmonella stimulates multiple signaling pathways that are key regulators of host cell survival. Nevertheless, little is known about the relative contributions of these pathways to Salmonella-mediated death of macrophages. We studied human monocytic U937 cells and found that apoptosis was induced by invading wild-type Salmonella typhimurium but not by phagocytosed, serum-opsonized, noninvasive Salmonella mutants. Pretreating U937 cells with inhibitors of tyrosine kinases or phosphatidylinositol-3 kinase (PI-3K) completely blocked phagocytosis of opsonized Salmonella mutants but did not affect invasion by wild-type Salmonella or the apoptosis caused by invasion. However, pretreatment with GGTI-298, a geranylgeranyltransferase-1 inhibitor that prevents prenylation of Cdc42 and Rac1, suppressed Salmonella-induced apoptosis by ∼70%. Transduction of Tat fusion constructs containing dominant-negative Cdc42 or Rac1 significantly inhibited Salmonella-induced cell death, indicating that the cytotoxicity of Salmonella requires activation of Cdc42 and Rac. In contrast to phagocytosis of opsonized bacteria, invasion by S. typhimurium stimulated Cdc42 and Rac1, regardless of the activities of tyrosine- or PI-3K. Moreover, Salmonella infection activated Akt protein in a tyrosine-kinase or PI-3K-dependent manner, and a reduced expression of Akt by antisense transfection rendered the cells more sensitive to apoptosis induced by opsonized Salmonella. These results indicate that direct activation of Cdc42 and Rac1 by invasive Salmonella is a prerequisite of Salmonella-mediated death of U937 cells, whereas the simultaneous activation of Akt by tyrosine kinase and PI-3K during receptor-mediated phagocytosis protects cells from apoptosis.
Targeting myeloperoxidase to azurophilic granules in HL-60 cells
Authors: Lemansky Peter , Gerecitano-Schmidek Mireille , Das Rajesh C , Schmidt Bernhard , Hasilik Andrej 
Published: September 2003

Abstract
Myeloperoxidase (MPO) is a cationic protein and one of the major constituents of azurophilic granules in neutrophils. Here, we examined whether intracellular transport of MPO and serglycin, a chondroitin sulfate (CS)-bearing proteoglycan, is correlated. First, we examined binding of MPO to CS–Sepharose and measured an ionic interaction, which was disrupted by 200–400 mM NaCl. Next, HL-60 promyelocytes were activated with a phorbol ester, which induced an almost complete rerouting of serglycin from the granular to the secretory pathway, concomitant with a similar effect on MPO transport and secretion. We then used the membrane-permeable cross-linker dithiobis(succininmidylpropionate; DSP) after labeling HL-60 cells with [35S]methionine and [35S]cysteine for 19 h. Immunoprecipitation of MPO revealed its cross-linking to high molecular material having the appearance of a proteoglycan in sodium dodecyl sulfate-polyacrylamide gels. This assumption was confirmed by labeling HL-60 cells with [35S]sulfate for 10 min followed by DSP cross-linking and immunoprecipitation. From three granular enzymes immunoprecipitated, only the cationic MPO was cross-linked to [35S]sulfate-labeled serglycin in appreciable quantities, whereas cathepsin D or β-N-acetylhexosaminidase was not. Thus, intracellular transport of MPO appears to be linked to that of serglycin. Extracts from high buoyant density organelles from human placenta containing MPO activity were subjected to CS-affinity chromatography. Proteins binding to CS were identified by mass spectrometry as MPO, lactoferrin, cathepsin G, and azurocidin/cationic antimicrobial protein of molecular weight 37 kDa, suggesting that serglycin may be a general transport vehicle for the cationic granular proteins of neutrophils.
Interaction of proteinase 3 with CD11b/CD18 (β2integrin) on the cell membrane of human neutrophils
Authors: David A , Kacher Y , Specks U , Aviram I 
Published: September 2003

Abstract
Proteinase 3 (PR3), the target autoantigen of antineutrophil cytoplasmic antibodies in the autoimmune vasculitis, Wegener’s granulomatosis, is a serine proteinase stored in granules of human neutrophils. As previously shown, PR3 is expressed also on the plasma membrane of unactivated neutrophils, and this expression increases in primed or stimulated cells. The current study demonstrates that membrane-bound PR3 colocalizes with the adhesion molecule CD11b/CD18 (β2 integrin). Immunoprecipitation experiments using plasma membranes of phorbol 12-myristate 13-acetate (PMA)-stimulated neutrophils revealed coimmunoprecipitation of PR3 with CD11b/CD18, indicating their location in the same complex. PR3 was also detected in TritonX-100-insoluble cytoskeleton of plasma membranes isolated from unactivated and activated neutrophils. Release of cytoskeletal PR3 by salt treatment implied electrostatic interaction with the enzyme. The serine protease inhibitor phenylmethylsulfonyl fluoride (PMSF) augmented membrane expression of PR3 in unactivated and PMA-stimulated neutrophils. PMSF significantly reduced adhesion of neutrophils to fibrinogen-coated plates and their NADPH oxidase activity. Moreover, the addition of exogenous PR3 (1–5 μg/ml) augmented the CD11b/CD18-dependent adhesion of neutrophils. Taken together, these results implicate the β2 integrin of neutrophils in their membrane association with PR3 and suggest a role of PR3 in the modulation of cell adhesion.
Nicotine induces human neutrophils to produce IL-8 through the generation of peroxynitrite and subsequent activation of NF-κB
Authors: Iho Sumiko , Tanaka Yukie , Takauji Rumiko , Kobayashi Chino , Muramatsu Ikunobu , Iwasaki Hiromichi , Nakamura Kishiko , Sasaki Yutaka , Nakao Kazuwa , Takahashi Takayuki 
Published: September 2003

AbstractLeukocytosis in tobacco smokers has been well recognized; however, the exact cause has not been elucidated. To test the hypothesis that tobacco nicotine stimulates neutrophils in the respiratory tract to produce IL-8, which causes neutrophilia in vivo, we examined whether nicotine induces neutrophil-IL-8 production in vitro; the causative role of NF-κB in its production, in association with the possible production of reactive oxygen intermediates that activate NF-κB; and the nicotinic acetylcholine receptors (nAChRs) involved in IL-8 production. Nicotine stimulated neutrophils to produce IL-8 in both time- and concentration-dependent manners with a 50% effective concentration of 1.89 mM. A degradation of IκB-α/β proteins and an activity of NF-κB p65 and p50 were enhanced following nicotine treatment. The synthesis of superoxide and the oxidation of dihydrorhodamine 123 (DHR) were also enhanced. The NOS inhibitor, nω-Nitro-l-arginine methyl ester, prevented nicotine-induced IL-8 production, with an entire abrogation of DHR oxidation, IκB degradation, and NF-κB activity. Neutrophils spontaneously produced NO whose production was not increased, but rather decreased by nicotine stimulation, suggesting that superoxide, produced by nicotine, generates peroxynitrite by reacting with preformed NO, which enhances the NF-κB activity, thereby producing IL-8. The nAChRs seemed to be involved in IL-8 production. In smokers, blood IL-8 levels were significantly higher than those in nonsmokers. In conclusion, nicotine stimulates neutrophil-IL-8 production via nAChR by generating peroxynitrite and subsequent NF-κB activation, and the IL-8 appears to contribute to leukocytosis in tobacco smokers.
Immature macrophages derived from mouse bone marrow produce large amounts of IL-12p40 after LPS stimulation
Authors: Oliveira M A P , Lima G M A C , Shio M T , Leenen P J M , Abrahamsohn I A 
Published: September 2003

Abstract
Production of IL-12 is an important indicator of the macrophage’s ability to regulate immune responses. In this study, we investigated the IL-12 production by macrophages in different developmental stages. To this end, macrophages were generated in vitro from precursors stimulated with M-CSF, GM-CSF or IL-3. Density separation yielded populations enriched in different maturation stages. Invariably, only cells banding at the 40−50% Percoll interface produced large amounts of IL-12p40 when stimulated with LPS, whereas only low levels of IL-12p70 were produced. These cells represented immature macrophages, as indicated by the absence of precursor markers CD31/ER-MP12, Ly-6C/ER-MP20 and ER-MP58, and by the low level of expression of mature-cell markers like ER-HR3, scavenger receptor and CD11b/Mac-1. Upon further maturation, the macrophages’ ability to produce IL-12p40 decreased, coinciding with increased nitric oxide production upon LPS stimulation. These results show that immature macrophages produce high levels of IL-12p40 and thus may either contribute to IL-12p70 production or regulate it.
Phase I and Pharmacokinetic Study of Two Different Schedules of Oxaliplatin, Irinotecan, Fluorouracil, and Leucovorin in Patients With Solid Tumors
Authors: Goetz Matthew P. , Erlichman Charles , Windebank Anthony J. , Reid Joel M. , Sloan Jeffrey A. , Atherton Pamela , Adjei Alex A. , Rubin Joseph , Pitot Henry , Galanis Evanthia , Ames Matthew M. , Goldberg Richard M. 
Published: September 2003

Purpose: We sought to determine the maximum-tolerated dose (MTD) and evaluate the toxicities and clinical activity of two irinotecan (CPT-11), fluorouracil (FU), leucovorin (LV), and oxaliplatin schedules in patients with advanced solid tumors. Additionally, we investigated the effect of CPT-11 on oxaliplatin pharmacokinetics. Patients and Methods: Thirteen patients (cohort 1) received intravenous CPT-11 (infusion) and FU/LV (bolus) on days 1, 8, 15, and 22 and oxaliplatin (infusion) on days 1 and 15 every 6 weeks for a total 37 courses (median, three courses) at three dose levels. Twenty-two cohort 2 patients received intravenous CPT-11/oxaliplatin (infusion, day 1) and FU/LV (90-minute bolus infusion, days 2 to 5) every 3 weeks for a total of 122 courses (median, four courses) at three dose levels. Pharmacokinetic and neurotoxicity assessments were performed at the cohort 2 MTD. Results: Dose-limiting toxicity (DLT) seen in both cohorts at the starting dose required dose de-escalation. Cohort 1 DLT included diarrhea and neutropenia. In cohort 2, diarrhea, vomiting, dehydration, neutropenia, febrile neutropenia, and paresthesias were DLTs. Antitumor activity was seen in both cohorts. In cohort 2, the total platinum area under the curve of patients increased 17% in cycle 2 (P = .048), but objective neurotoxicity was not seen. Conclusion: The toxicities resulting from the addition of oxaliplatin to CPT-11/FU/LV are significant but manageable. The MTDs for the weekly schedule are CPT-11 (75 mg/m2), oxaliplatin (50 mg/m2), FU (320 mg/m2), and LV (20 mg/m2); and, for the 3-weekly schedule, the MTDs are CPT-11 (175 mg/m2), oxaliplatin (85 mg/m2), FU (240 mg/m2), and LV (20 mg/m2). Second-cycle platinum accumulation raises the possibility for enhanced cumulative neurotoxicity with CPT-11/oxaliplatin combinations.