Macrophage-derived human resistin is induced in multiple helminth infections and promotes inflammatory monocytes and increased parasite burden.

Parasitic helminth infections can be associated with lifelong morbidity such as immune-mediated organ failure. A better understanding of the host immune response to helminths could provide new avenues to promote parasite clearance and/or alleviate infection-associated morbidity. Murine resistin-like molecules (RELM) exhibit pleiotropic functions following helminth infection including modulating the host immune response; however, the relevance of human RELM proteins in helminth infection is unknown. To examine the function of human resistin (hResistin), we utilized transgenic mice expressing the human resistin gene (hRetnTg+). Following infection with the helminth Nippostrongylus brasiliensis (Nb), hResistin expression was significantly upregulated in infected tissue. Compared to control hRetnTg- mice, hRetnTg+ mice suffered from exacerbated Nb-induced inflammation characterized by weight loss and increased infiltration of inflammatory monocytes in the lung, along with elevated Nb egg burdens and delayed parasite expulsion. Genome-wide transcriptional profiling of the infected tissue revealed that hResistin promoted expression of proinflammatory cytokines and genes downstream of toll-like receptor signaling. Moreover, hResistin preferentially bound lung monocytes, and exogenous treatment of mice with recombinant hResistin promoted monocyte recruitment and proinflammatory cytokine expression. In human studies, increased serum resistin was associated with higher parasite load in individuals infected with soil-transmitted helminths or filarial nematode Wuchereria bancrofti, and was positively correlated with proinflammatory cytokines. Together, these studies identify human resistin as a detrimental factor induced by multiple helminth infections, where it promotes proinflammatory cytokines and impedes parasite clearance. Targeting the resistin/proinflammatory cytokine immune axis may provide new diagnostic or treatment strategies for helminth infection and associated immune-mediated pathology

Altered expression of cytokines in mice infected intranasally with two syncytial variants of Herpes simplex virus type 1

Immune evasion strategies are important for the onset and the maintenance of viral infections. Many viruses have evolved mechanisms to counteract or suppress the host immune response. We have previously characterized two syncytial (syn) variants of Herpes simplex 1 (HSV-1) strain F, syn14-1 and syn17-2, obtained by selective pressure with a natural carrageenan. These variants showed a differential pathology in vaginal and respiratory mucosa infection in comparison with parental strain. In this paper, we evaluated the modulation of immune response in respiratory mucosa by these HSV-1 variants. We observed altered levels of Tumor Necrosis Factor-α and Interleukin-6 in lungs of animals infected with the syn14-1 and syn17-2 variants compared with the parental strain. Also, we detected differences in the recruitment of immune cells to the lung in syn variants infected mice. Both variants exhibit one point mutation in the sequence of the gene of glycoprotein D detected in the ectodomain of syn14-1 and the cytoplasmic tail of syn17-2. Results obtained in the present study contribute to the characterization of HSV-1 syn variants and the participation of the cellular inflammatory response in viral pathogenesis.Fil: Artuso, María Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Linero, Florencia Natalia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica. Laboratorio de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gazzaniga, Silvina Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Scolaro, Luis Alberto. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica. Laboratorio de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pujol, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Wainstok, Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Carlucci, Maria Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentin

Small particle-size talc is associated with poor outcome and increased inflammation in thoracoscopic pleurodesis

Rationale: Talc is very effective for pleurodesis, but there is concern about complications, especially acute respiratory distress syndrome. Objectives: It was the aim of this study to investigate if talc with a high concentration of small particles induces greater production of cytokines, and if pleural tumor burden has any influence on the local production and spillover of cytokines to the systemic circulation and eventual complications. Methods: We investigated 227 consecutive patients with malignant effusion submitted to talc pleurodesis. One hundred and three patients received 'small-particle talc' (ST; containing about 50% particles <10 ¿m) and 124 received 'large-particle talc' (with <20% particles <10 ¿m). Serial samples of both pleural fluid and blood were taken before and 3, 24, 48 and 72 h after thoracoscopy. Also, mesothelial cells were stimulated with both types of talc in vitro. Measurements and Results: Interleukin-8, tumor necrosis factor-¿, vascular endothelial growth factor, basic fibroblast growth factor and thrombin-antithrombin complex were measured in all samples. Early death (<7 days after talc) occurred in 8 of 103 patients in the ST and in 1 of 124 in the 'large-particle talc' group (p = 0.007). Patients who received ST had significantly higher proinflammatory cytokines in pleural fluid and serum after talc application, and also in supernatants of the in vitro study. Pleural tumor burden correlated positively with proinflammatory cytokines in serum, suggesting that advanced tumor states induce stronger systemic reactions after talc application. Conclusions: ST provokes a strong inflammatory reaction in both pleural space and serum, which is associated with a higher rate of early deaths observed in patients receiving it.Instituto de Salud Carlos III FIS 04/028

Effect of Perceived Stress on Cytokine Production in Healthy College Students

Chronic psychological stress impairs antibody synthesis following influenza vaccination. Chronic stress also increases circulating levels of proinflammatory cytokines and glucocorticoids in elders and caregivers, which can impair antibody synthesis. The purpose of this study was to determine whether psychological stress increases ex vivo cytokine production or decreases glucocorticoid sensitivity (GCS) of peripheral blood leukocytes from healthy college students. A convenience sample of Reserve Officer Training Corps (ROTC) students completed the Perceived Stress Scale (PSS). Whole blood was incubated in the presence of influenza vaccine and dexamethasone to evaluate production of interleukin-6 (IL-6), interleukin-1-beta (IL-1β), tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ). Multiple regression models controlling for age, gender, and grade point average revealed a negative relationship between PSS and GCS for vaccine-stimulated production of IL-1β, IL-6, and TNF-α. These data increase our understanding of the complex relationship between chronic stress and immune function

Inhaled Interleukin-10 before and after induction of experimental endotoxemia in the rat : effects on the inflammatory response

To determine the effects of inhaled IL-10 at different doses and different time points on the pulmonary and systemic inflammatory response during endotoxemia, 48 ventilated, anaesthetized rats (mean body weight ± standard deviation, 500 ± 33g) were randomly assigned to six groups (n = 8, each). Interleukin-10 was nebulised either prior to or following the intravenous injection of LPS (5mg/kg) at two doses (5.0 mycro-g or 0.5 mycro-g) in our groups. Eight rats received the same insult with no further treatment (LPS-only group). Another eight rats served as controls without endotoxemia but with aerosolized phosphate-buffered saline, the solvent of IL-10 (Sham group). Concentrations of TNF-alpha, IL-1beta, IL-6, and IFN-gamma were analyzed in plasma and bronchoalveolar lavage fluid (BALF). In addition, the nitrite release from ex-vivo cultured alveolar macrophages was determined. As compared to the LPS-only group, the concentrations of the proinflammatory cytokines TNF-alpha, IL-1beta, IL-6, and IFN-gamma in plasma were significantly reduced in the group, which inhaled 5 mycro-g IL-10 before LPS injection (p< 0.0125). Spontaneous nitrite release from exvivo cultured alveolar macrophages was suppressed in this group (p< 0.0125). Inhalation of 0.5 mycro-g IL-10 before LPS injection and both dosages of IL-10 inhalation (5 mycro-g or 0.5 mycro-g) after LPS injection did not significantly influence either inflammatory cytokine concentrations in BALF, in plasma or the nitrite release from ex-vivo cultured alveolar macrophages. In this study, inhaled IL-10 only demonstrated anti-inflammatory effects when it was administered at 5 mycro-g prior to the induction of experimental endotoxemia. Interleukin-10 aerosol had no effect when it was given either following induction of endotoxemia or given at a lower dosage (which here was 0.5 mycro-g) either before or following injection of lipopolysaccharide.Das "Acute Respiratory Distress Syndrome" (ARDS) ist eine akut auftretende, überwiegend Sepsis-induzierte, inflammatorische Erkrankung der Lunge mit hoher Letalität. Ein komplexes Netzwerk aus Zytokinen und anderen proinflammatorischen Mediatoren unterhält die pulmonale Entzündungreaktion. Dem Zytokin Interleukin-10 (IL-10) könnte in diesem Zusammenhang aufgrund seines spezifisch antiinflammatorischen und immunmodulierenden Wirkspektrums eine therapeutische Bedeutung zukommen. In tierexperimentellen Untersuchungen konnten die protektiven Wirkungen von systemisch appliziertem Interleukin-10 bezüglich verringerter Wirkspiegel proinflammatorischer Mediatoren sowie des Überlebens der Versuchstiere bei Sepsis belegt werden. In einer Untersuchung an ARDS-Erkrankten wiesen Patienten, deren bronchoalveoläre Lavage (BAL) hohe Konzentrationen an Interleukin-10 enthielt, eine signifikant niedrigere Letalität auf als Patienten mit niedriger IL-10-Konzentration. Die Inhalation von IL-10 über den Luftweg könnte lokal in der Lunge die Freisetzung von Entzündungsmediatoren verringern und so den Verlauf eines ARDS positiv beeinflussen. Im Rahmen einer bereits durchgeführten Studie der eigenen Arbeitsgruppe konnte gezeigt werden, dass die Inhalation von IL-10 (0.19 mycro-g/Tier) vor Induktion einer experimentellen Endotoxinämie (Beobachtungszeitraum 6h) zur signifikanten Reduktion proinflammatorischer Zytokine im Plasma sowie der BAL führte. Daneben bewirkte IL-10 Aerosol eine signifikante Verringerung der Nitritproduktion aus ex vivo kultivierten Alveolarmakrophagen (AM). Mit der vorliegenden Studie sollte untersucht werden, ob vernebeltes IL-10 auch in einer geringeren Dosierung als in der ersten Studie angewandt antiinflammatorisch wirksam ist. Daneben sollte geklärt werden, ob der Zeitpunkt der Applikation des IL-10 Aerosol relevant ist. Konkret sollte untersucht werden, ob die Inhalation von IL-10 erst nach Induktion der experimentellen Endotoxinämie ebenfalls antinflammatorisches Potential besitzt. Die Generierung und Verneblung des IL-10 Aerosols erfolgte in der vorliegenden Untersuchung mittels eines speziell für diesen Einsatz von der eigenen Arbeitsgruppe entwickelten und charakterisierten Verneblersystems. Der Vernebler produziert stabil Aerosopartikel, deren Größenverteilung (rund 2 mycro-m) mit hoher Wahrscheinlichkeit in alvelären Bereichen deponiert. Die alveoläre Depositionsfraktion des Verneblers beträgt rund 4% und liegt damit in einem Bereich, der aus der Humanmedizin für die Verneblung bei intubierten Patienten bekannt ist. An 48 narkotisierten, kontrolliert beatmeten Ratten wurde die antiinflammatorische Wirkung eines IL-10-Aerosols untersucht. Die Induktion des experimentellen Lungenschadens erfolgte durch intravenöse Injektion von Endotoxin (Lipopolysaccharid; LPS, in einer Dosierung von 5mg/kg). Als löslicher Bestandteil der Membran gram-negativer Bakterien führt LPS über die Freisetzung proinflammatorischer Substanzen zu entzündlichen Reaktionen, die lokal beschränkt oder auch systemisch auftreten können. Bei Versuchstieren unterschiedlicher Spezies bewirkt die systemische Applikation von LPS pulmonale Veränderungen, die denen des septisch bedingten ARDS des Menschen qualitativ entsprechen. Die Tiere wurden zufällig in eine der sechs Versuchsgruppen eingeteilt (je n=8): Die LPS-Gruppe erhielt eine LPS-Injektion (5 mg/kg/KG) ohne anschließende therapeutische Intervention. Die mit IL-10 behandelten Tiere erhielten das IL-10-Aerosol entweder vor oder nach Induktion der experimentellen Endotoxinämie nach unten genanntem Protokoll. In einer Kontroll (Sham)-Gruppe wurde die Auswirkung von Narkose, chirurgischer Präparation, Beatmung und Aerosolapplikation (IL-10-Trägerlösung; phosphatgepufferte Kochsalzlösung) evaluiert. Neben der in vivo Beobachtung von Hämodynamik (Herzfrequenz, mittlerer arterieller Blutdruck), Lungenmechanik, arteriellen Blutgasen und Blutbild, untersuchten wir anhand von Blutproben und einer Bronchoalveolären Lavage (BAL) die systemische und pulmonale Inflammation (inflammatorische Zytokine TNFalpha, IL-1beta, IL-6 und IFNgamma in Plasma und BAL). Die Verneblung von IL-10 erfolgte in zwei Dosierungen und zu zwei Zeitpunkten: in einer Gruppe wurde IL-10 in einer Dosierung von 5.0 mycro-g (0.19 mycro-g/Tier) vor, und in einer weiteren Gruppe nach Induktion der experimentellen Endotoxinämie vernebelt. In zwei weiteren Versuchgruppen wurde IL-10 in einer Dosierung von 0.5 mycro-g (0.019 mycro-g/Tier) ebenfalls vor sowie nach Injektion von LPS vernebelt. Die Endotoxinämie führte nur zu geringen Verschlechterungen der klinischen Parameter, aber sowohl pulmonal (BAL) als auch systemisch (Plasma) zeigte sich ein Anstieg proinflammatorischer Mediatoren. Gegenüber den Tieren, deren Endotoxinämie unbehandelt blieb, bewirkte nur die Inhalation von IL-10 in der höheren Dosierung (5 mycro-g) das signifikante Abfallen der proinflammatorischen Zytokine TNFalpha, IL-1beta, IL-6 und IFNgamma im Plasma sowie der Freisetzung von Nitrit aus kultivierten AM. IL-10 Aerosol hatte in keiner Dosierung respektive zu keinem Applikationszeitpunkt antiinflammatorische Effekte auf die Zytokinkonzentrationen in der BAL. Die präemptive Vernebelung von IL-10 in einer Dosierung von 5 mycro-g (0.19 mycro-g/Tier) vor Induktion einer experimentellen Endotoxinämie zeigte sowohl auf die AM Kultur als auch systemisch (Plasma) antinflammatorisches Wirkprofil. Demgegenüber zeigte IL-10 keine antinflammatorische Effekte, wenn es erst nach Injektion von LPS oder aber in geringerer Dosierung vernebelt wurde. Zur antiinflammatorischen Therapie der experimentellen Endotoxinämie durch LPS Injektion in der Spezies Ratte erscheint IL-10 Aerosol nur wirksam, wenn es in ausreichender Dosierung (5 mycro-g) sowie vor Injektion von LPS appliziert wird

Placental-mediated increased cytokine response to lipopolysaccharides: a potential mechanism for enhanced inflammation susceptibility of the preterm fetus.

BackgroundCerebral palsy is a nonprogressive motor impairment syndrome that has no effective cure. The etiology of most cases of cerebral palsy remains unknown; however, recent epidemiologic data have demonstrated an association between fetal neurologic injury and infection/inflammation. Maternal infection/inflammation may be associated with the induction of placental cytokines that could result in increased fetal proinflammatory cytokine exposure, and development of neonatal neurologic injury. Therefore, we sought to explore the mechanism by which maternal infection may produce a placental inflammatory response. We specifically examined rat placental cytokine production and activation of the Toll-like receptor 4 (TLR4) pathway in response to lipopolysaccharide exposure at preterm and near-term gestational ages.MethodsPreterm (e16) or near-term (e20) placental explants from pregnant rats were treated with 0, 1, or 10 μg/mL lipopolysaccharide. Explant integrity was assessed by lactate dehydrogenase assay. Interleukin-6 and tumor necrosis alpha levels were determined using enzyme-linked immunosorbent assay kits. TLR4 and phosphorylated nuclear factor kappa light chain enhancer of activated B cells (NFκB) protein expression levels were determined by Western blot analysis.ResultsAt both e16 and e20, lactate dehydrogenase levels were unchanged by treatment with lipopolysaccharide. After exposure to lipopolysaccharide, the release of interleukin-6 and tumor necrosis alpha from e16 placental explants increased by 4-fold and 8-9-fold, respectively (P &lt; 0.05 versus vehicle). Conversely, interleukin-6 release from e20 explants was not significantly different compared with vehicle, and tumor necrosis alpha release was only 2-fold higher (P &lt; 0.05 versus vehicle) following exposure to lipopolysaccharide. Phosphorylated NFκB protein expression was significantly increased in the nuclear fraction from placental explants exposed to lipopolysaccharide at both e16 and e20, although TLR4 protein expression was unaffected.ConclusionLipopolysaccharide induces higher interleukin-6 and tumor necrosis alpha expression at e16 versus e20, suggesting that preterm placentas may have a greater placental cytokine response to lipopolysaccharide infection. Furthermore, increased phosphorylated NFκB indicates that placental cytokine induction may occur by activation of the TLR4 pathway

Cooperative Stimulation of Dendritic Cells by Cryptococcus neoformans Mannoproteins and CpG Oligodeoxynucleotides

While mannosylation targets antigens to mannose receptors on dendritic cells (DC), the resultant immune response is suboptimal. We hypothesized that the addition of toll-like receptor (TLR) ligands would enhance the DC response to mannosylated antigens. Cryptococcus neoformans mannoproteins (MP) synergized with CpG-containing oligodeoxynucleotides to stimulate enhanced production of proinflammatory cytokines and chemokines from murine conventional and plasmacytoid DC. Synergistic stimulation required the interaction of mannose residues on MP with the macrophage mannose receptor (MR), CD206. Moreover, synergy with MP was observed with other TLR ligands, including tripalmitoylated lipopeptide (Pam3CSK4), polyinosine-polycytidylic acid (pI:C), and imiquimod. Finally, CpG enhanced MP-specific MHC II-restricted CD4+ T-cell responses by a mechanism dependent upon DC expression of CD206 and TLR9. These data suggest a rationale for vaccination strategies that combine mannosylated antigens with TLR ligands and imply that immune responses to naturally mannosylated antigens on pathogens may be greatly augmented if TLR and MR are cooperatively stimulated.National Institutes of Health (RO1 AI25780, RO1 AI37532, K08 AI 53542

Targeting neuroinflammation in Alzheimer’s disease

Almost 47 million people suffer from dementia worldwide, with an estimated new case diagnosed every 3.2 seconds. Alzheimer’s disease (AD) accounts for approximately 60%–80% of all dementia cases. Given this evidence, it is clear dementia represents one of the greatest global public health challenges. Currently used drugs alleviate the symptoms of AD but do not treat the underlying causes of dementia. Hence, a worldwide quest is under way to find new treatments to stop, slow, or even prevent AD. Besides the classic targets of the oldest therapies, represented by cholinergic and glutamatergic systems, β-amyloid (Aβ) plaques, and tau tangles, new therapeutic approaches have other targets. One of the newest and most promising strategies is the control of reactive gliosis, a multicellular response to brain injury. This phenomenon occurs as a consequence of a persistent glial activation, which leads to cellular dysfunctions and neuroinflammation. Reactive gliosis is now considered a key abnormality in the AD brain. It has been demonstrated that reactive astrocytes surround both Aβ plaques and tau tangles. In this condition, glial cells lose some of their homeostatic functions and acquire a proinflammatory phenotype amplifying neuronal damage. So, molecules that are able to restore their physiological functions and control the neuroinflammatory process offer new therapeutic opportunities for this devastating disease. In this review, we describe the role of neuroinflammation in the AD pathogenesis and progression and then provide an overview of the recent research with the aim of developing new therapies to treat this disorder

Driving chronicity in rheumatoid arthritis: perpetuating role of myeloid cells

Acute inflammation is a complex and tightly regulated homeostatic process that includes leukocyte migration from the vasculature into tissues to eliminate the pathogen/injury, followed by a pro-resolving response promoting tissue repair. However, if inflammation is uncontrolled as in chronic diseases such as Rheumatoid Arthritis (RA) it leads to tissue damage and disability. Synovial tissue inflammation in RA patients is maintained by sustained activation of multiple inflammatory positive-feedback regulatory pathways in a variety of cells including myeloid cells. In this review, we will highlight recent evidence uncovering biological mechanisms contributing to the aberrant activation of myeloid cells that contributes to perpetuation of inflammation in RA, and discuss emerging data on anti-inflammatory mediators contributing to sustained remission that may inform a novel category of therapeutic targets