bluuebunny/crossref_metadata_2025 huggingface dataset:
Dendritic cells from different tissues induce production of different T cell cytokine profiles
Authors: Everson Michael P , McDuffie Deborrah S , Lemak David G , Koopman William J , McGhee Jerry R , Beagley Kenneth W
Published: January 2018

The precise role of antigen-presenting cells (APC) in regulating the balance of T-helper type 1 (Th1) and T-helper type 2 (Th2) cytokine production is unclear. Dendritic cells (DC), the most potent APC for activation of naive T cells, were found to regulate Th1 and Th2 cytokine profiles in a fashion dependent upon their tissue of origin. Spleen (systemic) DC induce mainly Th1 cytokines and Peyer’s patch (mucosal) DC induce predominantly Th2 cytokines. These findings support the current concept that different tissues, each with its distinct microenvironment of cytokines, hormones, and cellular elements, are involved in the selection, promotion, and/or maintenance of different immune responses. With regard to DC, it is apparent that the tissue of DC origin determines the cytokine profiles produced by T cells and that DC from different tissues favor either cellular versus humoral immune responses by influencing T cell cytokine production.
Identification of factors from rat neutrophils responsible for cytotoxicity to isolated hepatocytes
Authors: Ho John S , Buchweitz John P , Roth Robert A , Ganey Patricia E
Published: January 2018

Activated polymorphonuclear neutrophils (PMNs) have been shown to be cytotoxic to rat hepatic parenchymal cells in vitro. This cytotoxicity could be observed without direct cell-cell contact, since the conditioned medium from PMNs activated with formyl-Met-Leu-Phe (fMLP) was effective in hepatocyte killing. To identify the toxic factor(s) released by PMNs, degranulation was induced by fMLP in PMNs pretreated with cytochalasin B. The contents released from the phagocytes were subjected to gel filtration on a Sephadex G-100 column. Resulting fractions were tested for cytotoxicity to isolated hepatocytes by using release of alanine aminotransferase as a marker for hepatocyte injury. Cytotoxicity was associated with fractions containing cathepsin G and elastase and not with other fractions, including those containing myeloperoxidase. The former two enzymes were purified to homogeneity with a carboxymethyl cellulose column. Each of these enzymes demonstrated concentration-dependent cytotoxicity to hepatocytes at concentrations >2 μg/mL. Moreover, they exhibited an additive cytotoxic effect. Effective concentrations for the combined cathepsin C and elastase in the incubation mixture were similar to the concentrations of these enzymes in PMN-conditioned medium that produced cytotoxicity to hepatocytes. Cytotoxicity of either purified enzyme or of conditioned medium could be prevented by plasma α-1-antitrypsin or soybean trypsin-chymotrypsin inhibitor, which were also potent inhibitors of enzymic activity of both cathepsin G and elastase. By contrast, the serine protease inhibitors, aprotinin and 4-(2-aminoethyl)-benzenesulfonyl fluoride, were less effective in inhibiting cathepsin G and elastase activities as well as cytotoxicity caused by the purified proteases or PMN-conditioned medium. These results support the hypothesis that cathepsin G and elastase are important mediators of hepatic parenchymal cell killing produced by activated PMNs in vitro.
Cytokines induced by Sendai virus in human peripheral blood leukocytes
Authors: Hua Ji , Liao Mei-June , Rashidbaigi Abbas
Published: January 2018

Human peripheral blood leukocytes (hPBL) are a rich source of natural leukocyte interferon (IFN-α) when treated with Sendai virus. Sendai virus treatment of hPBL will also result in significant production of several chemokines and cytokines such as macrophage inflammatory protein-1α (MIP-1α), MIP-1β, RANTES, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-8, in a time-dependent way. A significant amount of MCP-1 is constitutively produced in overnight culture of leukocytes. The most abundant cytokine is IFN-α, which is induced to its maximum level approximately 11–15 h after addition of Sendai virus. The amount of IFN-α induced at 15 h after Sendai virus treatment is more than 16-fold higher than those of MIP-1α, MIP-1β, and RANTES. IFN-α is also induced more than 60-fold higher than TNF-α and IL-8. The amount of IL-6 induced is approximately 400-fold less than IFN-α. Limited amounts of other cytokines such as IL-1α, IL-1β, macrophage colony-stimulating factor, TNF-β, and IFN-γ are also induced in Sendai virus-treated hPBL. No measurable amount of granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor, leukemia inhibitory factor, IL-2, IL-3, IL-4, IL-5, IL-7, IL-10, IL-11, or IL-12 was induced in the supernatant of Sendai virus-treated hPBL.
Effects of released products from platelets on neutrophilic adhesion to endothelial cells and nylon fibers
Authors: Oryu Makoto , Sakamoto Haruhiko , Ogawa Yoshitada , Tanaka Sumiko , Sakamoto Noriko
Published: January 2018

In this study, the effects of platelet release products (PRPr), ATP, and ADP on the adhesion of human neutrophils to human umbilical vein endothelial cells (HUVEC) and nylon fibers (NF) are described and the implications of various adhesion molecules are considered. Adhesion of neutrophils to HUVEC and NF was increased by PRPr, ATP, and ADP, while their adhesion-increasing actions were cancelled or considerably repressed by apyrase treatment. When anti-CD11a or anti-CD11b was added to neutrophils with PRPr, ATP, or ADP, the adhesion-increasing action was cancelled or considerably repressed. On the other hand, anti-ICAM-1 and anti-CD35 had no significant effects on this action. The above results indicated that platelets, through ATP and ADP in PRPr, increased the adhesion of neutrophils to endothelial cells and foreign bodies. Although it was suggested that the adhesion-increasing action was at least partially based on CD11a and CD11b, ICAM-1 and CD35 had no part in the enhancement of the adhesion.
Polymorphonuclear neutrophils pulsed with synthetic peptides efficiently activate memory cytotoxic T lymphocytes
Authors: Reali Eva , Guerrini Remo , Moretti Sabrina , Spisani Susanna , Lanza Francesco , Tomatis Roberto , Traniello Serena , Gavioli Riccardo
Published: January 2018

Polymorphonuclear neutrophils (PMNs), traditionally considered effector cells in the inflammatory response, have recently been regarded as potential regulators of the immune response. In the present study we investigate whether PMNs are efficient antigen-presenting cells for reactivation of memory cytotoxic T lymphocytes (CTLs). PMNs were pulsed with synthetic peptides derived from Epstein-Barr virus (EBV) antigens. We have used the IVTDFSVIK (IVT) peptide derived from the Epstein-Barr virus—encoded nuclear antigen 4 protein, corresponding to the immunodominant epitope of HLA-A11–restricted CTL responses, and the CLGGLLTMV (CLG) peptide derived from the latent membrane protein 2 antigen, representing a subdominant epitope of HLA-A2–restricted CTL responses. The data indicate that peptide-pulsed PMNs selectively activate specific CTL responses to both immunodominant and subdominant epitopes. The efficiency of CTL induction by PMNs was comparable to that observed with the conventional method of EBV-specific CTL reactivation with the autologous lymphoblastoid cell line, as well as with peptide-pulsed monocyte-enriched adherent cells. On the contrary, unactivated peptide-pulsed lymphocytes failed to induce an epitope-specific CTL response. These results demonstrate that PMNs efficiently present antigens to memory virus-specific CTLs and suggest that they may have a role as antigen-presenting cells.
Expansion of the γδ T cell subset in vivo during bloodstage malaria in B cell-deficient mice
Authors: van der Heyde Henri C , Elloso M Merle , Chang Wun-Ling , Pepper Barbara J , Batchelder Joan , Weidanz William P
Published: January 2018

Mice rendered B cell-deficient either by chronic anti-μ treatment initiated at birth or by gene knockout (JHD and μ-MT mice) suppressed acute Plasmodium chabaudi infections with a time course similar to intact control mice. Moreover, both kinds of B cell-deficient mice showed a 50- to 100-fold increase in splenic γδ T cell number after suppression of parasitemia compared with uninfected B cell-deficient controls; the magnitude of this increase resulted in significantly (P < 0.05) greater numbers of splenic γδ T cells in the B cell-deficient mice than in infected B cell-intact controls (about 10-fold). In contrast, the number of splenic CD4+ αβ T cells was only slightly elevated (< 2-fold) in both kinds of B cell-deficient mice compared with their intact controls. The number of splenic γδ T cells following suppression of P. vinckei parasitemia was approximately ninefold greater in JHD mice than in C57BL/6 controls, whereas similar numbers of splenic CD4+ αβ T cells were detected. Maximal numbers of γδ T cells were in cell-cycle in both JHD and C57BL/6 mice during descending P. chabaudi parasitemia, but the number of γδ T cells in cell-cycle was greater in B cell-deficient mice than in intact controls. Interleukin-10 (IL-10), a potent TH1 cell-suppressive molecule, does not appear to down-regulate the γδ T cell response during malaria in B cell-intact mice because the magnitude of the γδ T cell response was not significantly greater in IL-10 knockout mice compared with heterozygote controls. These findings collectively indicate that a markedly enhanced expansion of the γδ T cell population occurs in the absence of B cells, and this expansion occurs predominantly during acute malaria when parasite burdens are similar in B cell-deficient animals and intact controls.
Chemotaxis by human neutrophils and their cytokineplasts treated with inhibitors of nitric oxide synthase: no suppression of orientation or trajectory
Authors: Malawista Stephen E , de Boisfleury Chevance Anne
Published: January 2018

Inhibitors of nitric oxide (NO) synthase are reported to inhibit both the adherence of polymorphonuclear leukocytes (PMN) to substrate and chemotaxis (directed locomotion) of PMN as determined in Boyden chamber assays. In the current study, we examined both human blood PMN and granule-poor motile cytoplasts derived from them (cytokineplasts, CKP), under direct microscopic observation with concomitant time-lapse video recording, for their ability to respond chemotactically to an erythrocyte destroyed by laser microirradiation. In this system we can observe directly and continuously the orientation and trajectory of PMN before, during, and after establishment of a chemotactic gradient. For both PMN and CKP we employed three different inhibitors of NO synthase (Nω-methyl-l-arginine, N-iminoethyl-l-ornithine, and diphenyleneiodonium) in at least twice the concentrations employed to inhibit chemotaxis of PMN in Boyden chambers or killing of bacteria in CKP. Although small differences in adhesion might not have been appreciated, treated PMN and CKP were each indistinguishable from untreated controls in their ability to orient in a newly created chemotactic gradient and in their trajectories toward the chemotactic target.
Unique CD8+ T cell-rich lymphoid aggregates in human uterine endometrium
Authors: Yeaman Grant R , Guyre Paul M , Fanger Michael W , Collins Jane E , White Hillary D , Rathbun Wayne , Orndorff Kenneth A , Gonzalez Jorge , Stern Judy E , Wira Charles R
Published: January 2018

Using confocal scanning laser microscopy of viable tissue sections, we have demonstrated organized lymphoid aggregates (LA), that have a unique structure, in the stratum basalis of uterine endometrium. These LA consist of a core of B cells surrounded by more numerous T cells and an outer halo of monocytes/macrophages. The T cells in the LA were almost exclusively CD8+CD4-. These CD8+ LA, in terms of both their T cell and B cell components, were either small or absent during the early proliferative stage of the menstrual cycle, significantly larger in size at mid-cycle and during the secretory phase, and absent in post-menopausal women, suggesting that their development is hormonally influenced. This new finding of a menstrual cycle-dependent, phenotypically unique, organized immune cell structure may lead to new insights into the mechanisms by which the endometrium accepts a semiallogeneic graft while providing resistance to infectious organisms.
Macrophage differentiation and expression of macrophage colony-stimulating factor in murine milky spots and omentum after macrophage elimination
Authors: Zhu Hong , Naito Makoto , Umezu Hajime , Moriyama Hiroshi , Takatsuka Hisakazu , Takahashi Kiyoshi , Shultz Leonard D
Published: January 2018

To elucidate the differentiation mechanisms of macrophages in the murine omentum, we studied the repopulation of these cells and the expression of macrophage colony-stimulating factor (M-CSF) in the milky spots and omental tissues in mice depleted of macrophages following administration of liposome-encapsulated dichloromethylene diphosphonate (clodronate). The macrophages in the omentum were spindle or dendritic in shape, expressed several macrophage-specific antigens and Ia antigen, and phagocytized intraperitoneally injected carbon particles. In the milky spots, macrophages and macrophage precursors were detected, and the number of precursors increased alter elimination of macrophages by intraperitoneal injection of liposome-encapsulated clodronate. Macrophage precursors in the milky spots proliferated, moved to the omentum, and transformed into dendritic-shaped macrophages. Expression of M-CSF mRNA extracted from the milky spots was markedly enhanced at 2 and 3 days after macrophage depletion. Localization of M-CSF protein and mRNA was observed in the stromal cells of the milky spots. In osteopetrosis (op/op) mutant mice that are defective in the production of functional M-CSF omental macrophages were absent. These results indicate that M-CSF locally produced in the milky spots plays an important role in providing a microenvironment for development and differentiation of omental macrophages.
Expression of TNF-α by human plasma cells in chronic inflammation
Authors: Di Girolamo Nick , Visvanathan Kumar , Lloyd Andrew , Wakefield Denis
Published: January 2018

Tumor necrosis factor-α (TNF-α) is a potent proinflammatory cytokine and mediator of the inflammatory response. It has been implicated in the pathogenesis of many inflammatory disorders, including rheumatoid arthritis (RA), septic shock, and Crohn's disease. Using a specific anti-human TNF-α antibody we detected immunoreactivity for this cytokine in the cytoplasm of inflammatory cells in several chronic inflammatory disorders, including RA, scleritis, and polyarteritis nodosa. These cells were identified predominantly as IgG-expressing plasma cells. Lymph nodes from patients with Hodgkin's lymphoma and breast cancer, but not from control subjects, were also found to contain TNF-α-positive plasma cells. Cultured EBV-B lymphocytes and a human plasma cell line (ARH-77) when stimulated with phorbol myristate acetate demonstrated cytoplasmic TNF-α immunoreactivity. Western blot analysis of cell membranes and conditioned media from both cell types revealed the presence of the 26-kDa membrane-bound form and the 17-kDa soluble form of TNF-α, respectively. TNF-α was quantitated by enzymelinked immunosorbent assay and found to be biologically active as determined by the L929 cytotoxicity assay. This is the first demonstration that plasma cells may be capable of modulating immune and inflammatory responses, not only by antibody production, but also by their secretion of a key inflammatory mediator, TNF-α. J.
HIV infection of macrophages and pathogenesis of AIDS dementia complex: interaction of the host cell and viral genotype
Authors: Cunningham A L , Naif H , Saksena N , Lynch G , Chang J , Li S , Jozwiak R , Alali M , Wang B , Fear W , Sloane A , Pemberton L , Brew B
Published: January 2018

AIDS dementia complex (ADC) develops in only a third of HIV-infected patients who progress to AIDS. Macrophages and microglial cells are the major cellular sites of productive HIV replication in brain. Using 11 blood isolates of HIV from asymptomatic patients there was marked variation in tropism and the level of productive infection in recently adherent monocytes and monocyte-derived macrophages cultured in vitro. However, less variation was seen with 19 blood isolates from advanced HIV infection and 11 postmortem tissue isolates from brain, cerebrospinal fluid, spleen, and lung. Newly adherent monocytes expressed CCR5 in all seven patients tested, consistent with their susceptibility to infection but not explaining the above variability. There is also marked regional variability in neuropathology in the brain of patients with ADC. We have demonstrated that there was marked variation in the V3 sequences of HIV clones from different regions of the cortex of a patient with ADC, suggesting independent evolution of HIV replication in brain. Furthermore, production of the neurotoxin quinolinic acid from HIV-infected macrophages varied, depending on the host and source of HIV isolate. Hence variations in viral genotype, production by infected macrophages, and subsequent toxin production may contribute to the variability in neuropathology between individuals and between different regions of the brain in the same individual.
Role of proinflammatory cytokines and β-chemokines in controlling HIV replication
Authors: Vicenzi Elisa , Biswas Priscilla , Mengozzi Manuela , Poli Guido
Published: January 2018

Several members of the cytokine network play an important role in controlling the replication of the human immunodeficiency virus (HIV) in several experimental systems. Their effects can be categorized in the following three functional groups: (1) HIV-inductive cytokines; (2) HIV-suppressive cytokines; (3) cytokines with both activating and inhibiting capacities. Studies on the mechanism of action of these molecules have highlighted the fact that several steps of the retrovirus life cycle, from binding to budding of progeny virions from the infected cell, are affected by cytokines. This general concept has been recently substantiated by the discovery that certain β-chemokines can act as blockers of viral entry by interfering with HIV coreceptors. Finally, it is important to recognize that cytokines have gone beyond their role as potential pathogenetic or protective endogenous cofactors in HIV replication and disease progression, and are becoming experimental therapeutic agents for HIV disease, best illustrated thus far by the case of interleukin-2.
Cellular and viral protein interactions regulating IκBα activity during human retrovirus infection
Authors: Hiscott John , Beauparlant Pierre , Crepieux Pascale , DeLuca Carmela , Kwon Hakju , Lin Rongtuan , Petropoulos Louisa
Published: January 2018

NF-κB/Rel transcription factors participate in the activation of numerous genes involved in immune regulation/inflammation including cytokines, cell surface receptors, adhesion molecules, and acute phase proteins. NF-κB activity is controlled by inhibitory proteins, IκBs, that maintain the DNA-binding forms of NF-κB in an inactive state in the cytoplasm. Many viruses, including the human retroviruses HIV-1 and HTLV-1, also utilize the NF-κB/IκB pathway to their transcriptional advantage during viral infection. Our recent studies have focused on the IκBα inhibitor and have characterized several protein interactions that modulate the functional activity of IκBα during human retrovirus infection. In this article, we summarize recent studies demonstrating that (1) chronic HIV-1 infection of human myelomonoblastic PLB-985 cells leads to constitutive NF-κB activity, activated in part due to enhanced IκBα turnover and increased NF-κB/Rel production; (2) HTLV-1 Tax protein physically associates with the IκBα protein in vivo and in vitro and also mediates a 20- to 40-fold stimulation of NF-κB DNA binding activity mediated via an enhancement of NF-κB dimer formation; (3) casein kinase II phosphorylates IκBα at multiple sites in the C-terminal PEST domain and regulates IκBα function; (4) transdominant forms of IκBα, mutated in critical Ser or Thr residues required for inducer-mediated (S32A, S36A) and/or constitutive phosphorylation block HIV LTR trans-activation and also effectively inhibit HIV-1 multiplication in a single cycle infection model; and (5) the amino-terminal 55aa of IκBα (NIK) interacts with the human homologue of dynein light chain 1, a small 9-kDa human homologue of the dynein light chain protein involved in microtubule and cytoskeletal dynamics. Together, our results highlight a number of intriguing molecular interactions between IκBα and cellular or viral proteins that modulate transcription factor activity and nuclear-cytoplasmic flow of host proteins.
Expression and function of the early activation antigen CD69 in murine macrophages
Authors: Marzio Rosa , Jirillo Emilio , Ransijn Adriana , Mauël Jacques , Corradin Sally Betz
Published: January 2018

CD69, a member of the natural killer cell gene complex family of signal transducing receptors, represents one of the earliest activation antigens in human and murine lymphocytes. In contrast, human monocytes may express CD69 in a constitutive fashion. We have evaluated the expression and function of CD69 in murine bone marrow-derived macrophages. CD69 expression as determined by flow cytometry was not constitutive but was induced by stimulation with interferon-γ (IFN-γ) plus bacterial lipopolysaccharide (LPS) or tumor necrosis factor α (TNF-α). Stimulation with LPS alone was equally effective. Infection with the protozoan parasite Leishmania did not induce CD69 expression nor influence CD69 up-regulation by IFN-γ plus LPS. Induction of CD69 expression was significantly inhibited in the presence of prostaglandin E2 or dibutyryl-cAMP. Stimulation of macrophages with anti-CD69 monoclonal antibody in the presence of IFN-γ induced both nitric oxide production and TNF-α release. Moreover, anti-CD69 stimulation of Leishmania-infected macrophages resulted in elimination of the intracellular parasite. These results suggest that CD69 is an activation antigen for murine macrophages and may serve as a signaling receptor for an as yet uncharacterized ligand.
Insulin-stimulated chemokinesis in normal human neutrophils is dependent on D-glucose concentration and sensitive to inhibitors of tyrosine kinase and phosphatidylinositol 3-kinase
Authors: Oldenborg Per-Arne , Sehlin Janove
Published: January 2018

This study shows that D-glucose and insulin, alone and in certain combinations, have chemokinetic effects on neutrophil granulocytes from healthy humans. A stimulatory chemokinetic effect of insulin was present at 40-160 μU/mL insulin but only in the presence of 5 mM, and not at 15 mM, D-glucose. D-Glucose alone dose-dependently increased the neutrophil locomotion, showing a maximum effect at 5–15 mM and a return toward the basal locomotion at 25 mM glucose. Because the stimulatory chemokinetic effects of 5 and 15 mM D-glucose alone were the same, it seems that the high glucose level does not inhibit the basic motile properties of the cells but may generate intracellular signals interfering with the signal transduction underlying the insulin effect. The tyrosine kinase inhibitor, genistein, or the phosphatidylinositol 3-kinase inhibitor, wortmannin, abolished the chemokinetic effect of 160 μU/mL insulin in the presence of 5 mM D-glucose. This indicates that the insulin effect on locomotion is indeed mediated by receptor-associated tyrosine kinase activation and involving phosphatidylinositol 3-kinase.
The effects of pregnancy on autoimmune diseases
Authors: Buyon Jill P
Published: January 2018

Internal gestation of a genetically foreign conceptus challenges the maternal host to circumvent immunological processes that recognize and eliminate nonself molecules. Accordingly, human viviparity involves a wide range of immunological modifications. This review examines the relationship between pregnancy and several autoimmune diseases prevalent in women. Pregnancy is associated with improvement in the clinical signs and symptoms of rheumatoid arthritis in more than 70% of patients. Maternal-fetal disparity in alleles of HLA-DRβl, DQα, and DQβ has been reported to be associated with pregnancies characterized by remission or improvement. These observations suggest that presentation of fetal DQα peptides might correct autoimmunity in patients with RA either by induction of maternal-regulatory T cells, or by affecting the maternal T cell receptor repertoire. In contrast, the course of systemic lupus erythematosus is more variable. Whether flare rates increase during or after pregnancy is unsettled, since individual patient series vary in the characteristics of patients accepted for study and in definitions of flare. Despite a high overall flare rate in some series approaching 60%, recorded flares were usually not severe. Only limited data are available regarding the incidence or outcome for either the mother with scleroderma or her fetus. The extent of diffuse skin disease and systemic involvement, particularly pulmonary, cardiac and renal, may be more important than the duration of the disease; limited disease carries a better prognosis for the mother and fetus. Highly specific autoantibody profiles in the mother (independent of whether she has a clinical disease) are associated with fetal demise and neonatal lupus syndromes, the most serious manifestation of which is isolated congenital heart block. The former is associated with antiphospholipid antibodies and the latter with antibodies directed against SSA/Ro and SSB/La polypeptides.
Human neutrophils are devoid of the integral membrane protein caveolin
Authors: Sengeløv Henrik , Voldstedlund Marianne , Vinten Jørgen , Borregaard Niels
Published: January 2018

The secretory vesicles of human neutrophils are rapidly mobilizable vesicles that contain several GPI-linked proteins, a characteristic feature of caveolae in other cells. To investigate whether secretory vesicles are structurally related to caveolae, we examined human neutrophils for the presence of caveolin, a major constituent of caveolae, by immunoblotting using monoclonal and polyclonal antibodies. Caveolin was not detected in lysates of human neutrophils nor in isolated plasma membrane/light membrane fractions in which secretory vesicles localize. In contrast, caveolin was readily detected in isolated membranes of adipose cells. We conclude that human neutrophils are devoid of caveolin and that secretory vesicles are not related to caveolae nor dependent on caveolae for mobilization.
Expression of macrophage-derived chemokine (MDC) mRNA in macrophages is enhanced by interleukin-1 β, tumor necrosis factor α, and lipopolysaccharide
Authors: Rodenburg R J T , Brinkhuis R F B , Peek R , Westphal J R , van Den Hoogen F H J , van Venrooij W J , van de Putte L B A
Published: January 2018

A cDNA encoding the CC chemokine MDC was isolated from a human macrophage cDNA library by differential hybridization using monocyte- and macrophage-specific cDNA probes. During monocyte to macrophage differentiation in vitro, MDC expression is first detected after 1 day of culturing and reaches maximum levels after 6 days when macrophages have fully matured, as judged from the expression of known macrophage marker genes. Exposure of macrophages to lipopolysaccharide (LPS) results in a dose-dependent increase in MDC mRNA levels, with maximum induction occurring after 6–8 h, whereas expression levels of macrophage inflammatory protein-1α (MIP-1α), MIP-2, interleukin-1β (IL-1β), and tumor necrosis factor α (TNF-α) respond much faster to LPS. Furthermore, MDC expression in macrophages is enhanced by the inflammatory mediators TNF-α and IL-1β. Similar to other TNF-α/IL-1β-inducible genes, costimulation of macrophages with both cytokines leads to higher MDC expression levels than stimulation with a single cytokine. By contrast, both resting and activated monocytes do not express MDC mRNA.
IgA Fc receptor (CD89) activation enables coupling to syk and Btk tyrosine kinase pathways: differential signaling after IFN-γ or phorbol ester stimulation
Authors: Launay Pierre , Lehuen Agnés , Kawakami Toshiaki , Blank Ulrich , Monteiro Renato C
Published: January 2018

IgA Fc receptors (FcαR) can mediate a variety of inflammatory responses. It has been demonstrated that the FcRγ subunit is critical in mediating signaling through FcαR. We show that aggregation of FcαR on U937 cells and blood neutrophils results in tyrosine phosphorylation of several intracellular proteins, including the FcR γ subunit, p72syk, and Bruton tyrosine kinase (Btk). Syk was found to be associated with FcαR and its phosphorylation was increased in phorbol myristate acetate (PMA)- and interferon-γ (IFN-γ)-treated U937 cells. In contrast, phosphorylation of Btk was only detected after cell treatment with PMA but not IFN-γ. These data indicate that signaling through FcαR γ2 involves at least two subfamilies of tyrosine kinases, syk and Btk. Our results also suggest that activation of tyrosine kinase pathways through FcαR depends on the activation state of the cell. This may be an important regulatory mechanism in IgA-mediated responses at inflammatory sites.
Mast cells produce ENA-78, which can function as a potent neutrophil chemoattractant during allergic airway inflammation
Authors: Lukacs Nicholas W , Hogaboam Cory M , Kunkel Steven L , Chensue Stephen W , Burdick Marie D , Evanoff Holly L , Strieter Robert M
Published: January 2018

The inflammatory response during allergic airway inflammation involves the recruitment of multiple leukocyte populations, including neutrophils, monocytes, lymphocytes, and eosinophils. All of these populations likely contribute to the pathology observed during repeated episodes of allergic airway inflammation. We have examined the role of a human neutrophil-specific chemokine (C-x-C), ENA-78, in a model of allergic airway responses and identified murine mast cells as a cellular source of an ENA-78-like molecule. Within this allergic airway model, neutrophil infiltration into the airway occurs within 4–8 h post-allergen challenge, persists within the airway until 24 h, and resolves by 48 h post-challenge. Neutrophil influx precedes the eosinophil infiltration, which peaks in the airway at 48 h post-allergen challenge. In this study the production of ENA-78 from challenged lungs demonstrated a significant increase in the allergen-, but not vehicle-, challenged lungs. In vivo neutralization of ENA-78 by passive immunization demonstrated a significant decrease in peak neutrophil infiltration at 8 h, with no effect on the eosinophil infiltration at 48 h post-challenge. Because ENA-78 has been shown to be chemotactic for neutrophils and given the involvement of mast cell degranulation in allergic responses, we examined mast cells for the presence of ENA-78. Cultured mast cells spontaneously released ENA-78, but on activation with IgE + antigen, NG-L-arginine methyl ester or compound 48/80 produced significantly increased levels of ENA-78. Supernatants from sonicated MC-9 mast cells induced an overwhelming influx of neutrophils into the BAL by 4 h post-intratracheal injection into mice, suggesting that the mast cell is a significant source of neutrophil chemotactic factors. Mast cell supernatant-mediated neutrophil infiltration was substantially decreased by preincubation of the supernatant with antibodies specific for ENA-78. These data indicate a major neutrophil chemotactic protein produced by mast cells during allergic responses may be mast cell-derived ENA-78.
Regulation of T helper cell differentiation by STAT molecules
Authors: Kaplan Mark H , Grusby Michael J
Published: January 2018

It is now well appreciated that the cytokines interleukin (IL)-12 and IL-4 are important for the generation of Th1 and Th2 cells, respectively. Only recently, however, have the molecular mechanisms by which these cytokines affect Th cell differentiation begun to be defined. Previous work from our laboratory has demonstrated that members of the signal transducer and activator of transcription (STAT) gene family are critical for the differentiation of Th cell subsets. In particular, Stat4-deficient mice show an impairment in the generation of Th1 cells, whereas Stat6-deficient animals do not generate Th2 cells. We have now generated Stat4-Stat6 double-deficient mice to determine whether STAT-independent pathways exist for the development of Th cell subsets. It is surprising that Th1 but not Th2 cells can be generated from double-deficient mice in vitro and these animals are able to mount an in vivo Th1 cell-mediated immune response. These results suggest a model of Th cell differentiation in which Stat4 and Stat6 have different roles in the development of Th cell subsets. J. Leukoc. Biol. 64: 2–5; 1998.
Neutrophils responded to immobilized lipopolysaccharide in the absence of lipopolysaccharide-binding protein
Authors: Nakatomi Kensuke , Aida Yoshitomi , Kusumoto Keisuke , Pabst Michael J , Maeda Katsumasa
Published: January 2018

Lipopolysaccharide (LPS) in solution primes neutrophils for enhanced release of superoxide in response to N-formyl-methionyl-leucyl-phenylalanine. We show that LPS immobilized on polystyrene or polypropylene acted on neutrophils by a mechanism different from that of LPS in solution. Coating the surface with 1% plasma, either before coating with LPS (plasma/LPS) or after coating with LPS (LPS/plasma), was essential to induce the LPS response in neutrophils. However, plasma could be replaced by fibrinogen, type I collagen or type IV collagen, or, to a lesser extent, by fibronectin or vitronectin, which was not true for LPS in solution. About 20% of the LPS added was immobilized on the plastic surfaces, based on its ability to adsorb anti-LPS antibody after extensive washing. The amount of soluble LPS that might have been released from surfaces during the incubation with neutrophils was too low to account for the priming by immobilized LPS. About 13–20 min was needed for neutrophils to become primed after incubation with immobilized LPS. Immobilized LPS induced up-regulation of CD11b/CD18 and latent alkaline phosphatase and also enhanced the adhesive response of neutrophils. Priming by immobilized LPS was inhibited by anti-CD14 antibody or by treatment of neutrophils with the LPS antagonist LA-14-PP. When immobilized LPS was treated with anti-LPS-binding protein (LBP) antibody, the response of neutrophils to LPS/plasma was inhibited but the response to plasma/LPS or fibrinogen/LPS was not. Thus, the LPS in plasma/LPS or fibrinogen/LPS acted on neutrophils in an LBP-independent manner. We conclude that the CD14-dependent LPS receptor system of neutrophils was capable of working in the absence of LBP, but only when LPS was immobilized on a surface coated with protein. J. Leukoc. Biol. 64: 177–184; 1998.
Interferon-α and granulocyte-macrophage colony-stimulating factor differentiate peripheral blood monocytes into potent antigen-presenting cells
Authors: Paquette Ronald L , Hsu Nicholas C , Kiertscher Sylvia M , Park Alice N , Tran Lawrence , Roth Michael D , Glaspy John A
Published: January 2018

The diverse roles of interferon-α (IFN-α) in regulating the immune response to infectious agents suggested that it might affect dendritic cell (DC) development. Peripheral blood mononuclear cells cultured with IFN-α and granulocyte-macrophage colony-stimulating factor (GM-CSF) developed a dendritic morphology and expressed high levels of the class I and II human leukocyte antigens (HLA), B7 costimulatory molecules, adhesion proteins, and CD40. Elevated DC expression of B7-2 and HLA-DR was observed with increasing IFN-α concentrations up to 5000 U/mL. The effects of IFN-α on DC immunophenotype were not reversed by adding neutralizing antibodies against interleukin-4 (IL-4) or tumor necrosis factor α to the cell cultures or by eliminating lymphocytes from the cultures. The addition of IFN-α to cultures containing optimal concentrations of IL-4 and GM-CSF significantly increased the B7-2 and HLA-DR levels above those present on DCs grown in two cytokines. The DCs generated with IFN-α and GM-CSF were potent antigen-presenting cells in allogeneic mixed leukocyte reactions. They also were capable of taking up, processing, and presenting tetanus toxin to autologous T lymphocytes. These results demonstrate an important role for IFN-α in the generation of DCs with potent antigen-presenting capabilities from peripheral blood monocytes. J. Leukoc. Biol. 64: 358–367; 1998.
Antibody-induced engagement of β2 integrins in human neutrophils causes a rapid redistribution of cytoskeletal proteins, Src-family tyrosine kinases, and p72syk that precedes de novo actin polymerization
Authors: Yan Sen Rong , Berton Giorgio
Published: January 2018

β2 Integrins mediate rearrangement of the cytoskeleton and activation of selective cell functions in neutrophils. To elucidate early events following β2 integrin ligation, we analyzed redistribution of cytoskeletal and signaling proteins as a consequence of antibody-induced integrin clustering. Incubation of neutrophils on surface-bound anti-β2 subunit antibodies induced a very rapid (within 1 min) redistribution of the cytoskeletal proteins talin, α-actinin, and paxillin, and the tyrosine kinases p58c-fgr, p53/56lyn, and p72syk to a cell fraction insoluble in Triton X-100. Cytoskeletal and signaling proteins redistribution preceded de novo actin polymerization because cytochalasin B did not inhibit this redistribution. Antibody engagement of all the three distinct β2 integrins (CD11a, CD11b, CD11c) expressed by neutrophils induced redistribution of cytoskeletal proteins and tyrosine kinases. Several tyrosine phosphorylated proteins were also rapidly redistributed as a consequence of β2 integrin engagement and this was not affected by blocking de novo actin polymerization with cytochalasin B. In addition, genistein, an inhibitor of tyrosine kinase activities which strongly reduced protein tyrosine phosphorylation, had no effect on redistribution of cytoskeletal proteins, Src-family kinases, and p72syk. These findings suggest that integrin-dependent cytoskeleton rearrangement in neutrophils occurs in at least two distinct steps and nucleation of some cytoskeletal proteins together with tyrosine kinases precedes rearrangement of the actin-based cytoskeleton and tyrosine kinases activation. On the basis of these and previous findings we propose a model explaining mechanisms of integrin signaling in neutrophils. J. Leukoc. Biol. 64: 401–408; 1998.
P-selectin and MAC-1 mediate monocyte rolling and adhesion to ECM-bound platelets under flow conditions
Authors: Kuijper P H M , Torres H I Gallardo , Houben L A M J , Lammers J-W J , Zwaginga J J , Koenderman L
Published: January 2018

Accumulation of monocyte-derived foam cells in focal areas of the atherosclerotic (A.S.-) lesion is one of the key events in early atherogenesis. Using a flow model for the damaged vessel wall, we examined the ability of ECM-bound platelets to induce monocyte tethering and adhesion. Whereas ECM-proteins alone induced monocyte adhesion only at low shear stresses (<100 mPa), ECM-bound platelets induced monocyte rolling and adhesion at shear stresses up to 240 mPa. Studies with specific antibodies showed that monocyte adhesion to platelets was mainly mediated by P-selectin and monocyte PSGL-1 (maximum inhibition 90%). β2-Integrin blocking CD18 and CD11b antibodies partly inhibited the arrest of rolling cells. Antibodies against other adhesion molecules such as LFA-1, PECAM-1, and β1-integrins had no effect. Even sparsely adhered platelets (~10% coverage of the surface) already strongly supported monocyte tethering. In conclusion, activated platelets present on ECM are a powerful adhesive substrate for monocyte recruitment under flow conditions. J. Leukoc. Biol. 64: 467–473; 1998.
Sulfite is released by human neutrophils in response to stimulation with lipopolysaccharide
Authors: Mitsuhashi Hideki , Nojima Yoshihisa , Tanaka Takaharu , Ueki Kazue , Maezawa Akira , Yano Shintaro , Naruse Takuji
Published: January 2018

Exposure to sulfite, a well-known air pollutant, induces inflammatory reactions characterized by neutrophil infiltration into the airways. Using a simple and sensitive assay for sulfite concentration in biological fluids, we demonstrate herein that human neutrophils released significant amounts of sulfite (1.0 nmol/h/107 cells) in response to lipopolysaccharide (LPS), a major component of bacterial endotoxin. A large proportion of the sulfite release by neutrophils was dependent on inorganic sulfate contained in culture media, suggesting production via the sulfate reducing pathway in this response. We also show that glucocorticoids and FK506 completely inhibit LPS-mediated sulfite release by neutrophils. Given the well-known antimicrobial activities of sulfite, our results suggest that sulfite acts as a neutrophil mediator of host defense. A putative role of sulfite as an endogenous biological mediator is further underscored by the observation that in vivo administration of LPS is associated with a marked increase in the serum concentration of sulfite in Wistar rats. Inhibition of sulfite release by immunosuppressive agents may contribute to increased susceptibility to bacterial infection commonly associated with the administration of these drugs. J. Leukoc. Biol. 64: 595–599; 1998.
Role of CD8+ and WC-1+ γ/δ T cells in resistance to Mycobacterium bovis infection in the SCID-bo mouse
Authors: Smith Ruth A , Kreeger John M , Alvarez Antonio J , Goin Jessica C , Davis William C , Whipple Diana L , Estes D Mark
Published: January 2018

The role of various effector T cell populations in the bovine immune response to Mycobacterium bovis infection is poorly understood. This is largely due to the difficulties associated with performing in vivo challenge studies in the natural host species. In this report, we utilized a fetal bovine-severe combined immunodeficient (SCID-bo) xenochimeric mouse model to study the protective role of two putative effector cell types, CD8+ T cells and a subpopulation of γ/δ T cells that express WC-1, a member of the cysteine-rich scavenger receptor superfamily (CRSR). We demonstrate that CD8+ T cells play a key role in protection and contribute substantially to bovine IFN-γ mRNA levels at 30 days post-infection. The role of WC-1 bearing cells to protection was less definitive but our results suggest that this population may play a pivotal role early in infection. Granuloma architecture was altered in anti-WC-1 (ILA29) but not anti-CD8 (ILA51) -treated animals, suggesting that this population may be involved in recruitment of various cell types to sites of infection. J. Leukoc. Biol. 65: 28–34; 1999.
P-selectin mediates neutrophil adhesion to endothelial cell borders
Authors: Burns Alan R , Bowden Robert A , Abe Yasunori , Walker David C , Simon Scott I , Entman Mark L , Smith C Wayne
Published: January 2018

During an acute inflammatory response, endothelial P-selectin (CD62P) can mediate the initial capture of neutrophils from the free flowing bloodstream. P-selectin is stored in secretory granules (Weibel-Palade bodies) and is rapidly expressed on the endothelial surface after stimulation with histamine or thrombin. Because neutrophil transmigration occurs preferentially at endothelial borders, we wished to determine whether P-selectin-dependent neutrophil capture (adhesion) occurs at endothelial cell borders. Under static or hydrodynamic flow (2 dyn/cm2) conditions, histamine (10-4 M) or thrombin (0.2 U/mL) treatment induced preferential (≥ 75%) neutrophil adhesion to the cell borders of endothelial monolayers. Blocking antibody studies established that neutrophil adhesion was completely P-selectin dependent. P-selectin surface expression increased significantly after histamine treatment and P-selectin immunostaining was concentrated along endothelial borders. We conclude that preferential P-selectin expression along endothelial borders may be an important mechanism for targeting neutrophil migration at endothelial borders. J. Leukoc. Biol. 65: 299–306; 1999.
The cellular immunology of multiple sclerosis
Authors: Al-Omaishi Jinan , Bashir Rifaat , Gendelman Howard E
Published: January 2018

Multiple sclerosis (MS) is a neurological disease that affects the central nervous system (brain and spinal cord) resulting in debilitating motor and sensory dysfunction. Its mean age of onset is 30 years and, with the exception of trauma, MS remains the most frequent cause of neurological disabilities for young adults. The disease is highly variable in its onset and progression. It may not be easily diagnosed, at least in its earliest stages. Significant disability is a hallmark of MS. Indeed, up to 50% of patients require walking aids and 10% are wheelchair-bound at 15 years after an initial diagnosis. Clinical features include deficits in sensory (parasthesias and numbness), motor (difficulties with fine movements and gait), balance, bladder, and sexual functions. Although the etiology for MS is not yet known, it is thought to be related to microbial, genetic, and/or environmental factors. Pathologically, MS is characterized by inflammation. An influx of mononuclear cells occurs through a disrupted blood–brain barrier into an immune-privileged central nervous system. The secretion of a variety of inflammatory cytokines and chemokines from glial cells leads to loss of myelin, disruption of oligodendrocyte integrity, and axonal loss. These events, in large measure, affect progressive neural atrophy. How brain inflammatory activities affect transendothelial migration of leukocytes into the brain and alter the process of myelination are the focal points for MS research activities. J. Leukoc. Biol. 65: 444-452; 1999.
Macrophage invasion does not contribute to muscle membrane injury during inflammation
Authors: Tidball James G , Berchenko Eugene , Frenette Jérôme
Published: January 2018

Previous observations have shown that neutrophil invasion precedes macrophage invasion during muscle inflammation and that peak muscle injury is observed at the peak of ED1+ macrophage invasion. We tested the hypothesis that neutrophil invasion causes subsequent invasion by ED1+ macrophages and that ED1+ macrophages then contribute significantly to muscle membrane injury during modified muscle use. Rat hindlimbs were unloaded for 10 days followed by reloading by normal ambulation to induce inflammation. Membrane injury was measured by assaying Evans blue-bound serum protein influx through membrane lesions. Muscle neutrophil populations increased significantly during the first 2 h of reloading but ED1+ macrophages did not increase until 24 h. Neutrophil invasion was uncoupled from subsequent macrophage invasion by reloading rat hindlimbs for 2hto cause neutrophil invasion, followed by resuspension for hours 2–24. This produced similar increases in neutrophil concentration as measured in muscles continuously reloaded for 24 h without causing an increase in macrophages. However, resuspension did not reduce the extent of muscle damage compared with that occurring in muscles that were reloaded continuously for 24 h. Thus, muscle invasion by neutrophils is not sufficient to cause invasion by ED1+ macrophages. In addition, muscle membrane injury that occurs during reloading is independent of invasion by ED1+ macrophages. J. Leukoc. Biol. 65: 492–498; 1999.