39 research outputs found
Desiccating stress-induced disruption of ocular surface immune tolerance drives dry eye disease
Dry eye is an allegedly autoimmune disorder for which the initiatingmechanisms and the targeted antigens in the ocular surface are not known,yet there is extensive evidence that a localized T helper type 1 (Th1)/Th17effector T cell response is responsible for its pathogenesis. In this work, weexplore the reconciling hypothesis that desiccating stress, which is usuallyconsidered an exacerbating factor, could actually be sufficient to skew theocular surface?s mucosal response to any antigen and therefore drive thedisease. Using a mouse model of dry eye, we found that desiccating stresscauses a nuclear factor kappa B (NF-jB)- and time-dependent disruption ofthe ocular surface?s immune tolerance to exogenous ovalbumin. Thispathogenic event is mediated by increased Th1 and Th17 T cells andreduced regulatory T cells in the draining lymph nodes. Conversely, topicalNF-jB inhibitors reduced corneal epithelial damage and interleukin (IL)-1band IL-6 levels in the ocular surface of mice under desiccating stress. Theobserved effect was mediated by an augmented regulatory T cell response, afinding that highlights the role of mucosal tolerance disruption in dry eyepathogenesis. Remarkably, the NF-jB pathway is also involved in mucosaltolerance disruption in other ocular surface disorders. Together, theseresults suggest that targeting of mucosal NF-jB activation could havetherapeutic potential in dry eye.Fil: Guzman, Mauricio. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Keitelman, Irene AngĂ©lica. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Sabbione, Florencia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Trevani, AnalĂa Silvina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Giordano, Mirta Nilda. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Galletti, JeremĂas GastĂłn. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin
Restoring Conjunctival Tolerance by Topical Nuclear FactorâÎșB Inhibitors Reduces Preservative-Facilitated Allergic Conjunctivitis in Mice
Purpose.: To evaluate the role of nuclear factorâÎșB (NF-ÎșB) activation in eye drop preservative toxicity and the effect of topical NF-ÎșB inhibitors on preservative-facilitated allergic conjunctivitis. Methods.: Balb/c mice were instilled ovalbumin (OVA) combined with benzalkonium chloride (BAK) and/or NF-ÎșB inhibitors in both eyes. After immunization, T-cell responses and antigen-induced ocular inflammation were evaluated. Nuclear factorâÎșB activation and associated inflammatory changes also were assessed in murine eyes and in an epithelial cell line after BAK exposure. Results.: Benzalkonium chloride promoted allergic inflammation and leukocyte infiltration of the conjunctiva. Topical NF-ÎșB inhibitors blocked the disruptive effect of BAK on conjunctival immunological tolerance and ameliorated subsequent ocular allergic reactions. In line with these findings, BAK induced NF-ÎșB activation and the secretion of IL-6 and granulocyte-monocyte colony-stimulating factor in an epithelial cell line and in the conjunctiva of instilled mice. In addition, BAK favored major histocompatibility complex (MHC) II expression in cultured epithelial cells in an NF-ÎșBâdependent fashion after interaction with T cells. Conclusions.: Benzalkonium chloride triggers conjunctival epithelial NF-ÎșB activation, which seems to mediate some of its immune side effects, such as proinflammatory cytokine release and increased MHC II expression. Breakdown of conjunctival tolerance by BAK favors allergic inflammation, and this effect can be prevented in mice by topical NF-ÎșB inhibitors. These results suggest a new pharmacological target for preservative toxicity and highlight the importance of conjunctival tolerance in ocular surface homeostasis.Fil: Guzman, Mauricio. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Sabbione, Florencia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Gabelloni, MarĂa Laura. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Vanzulli, Silvia. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Trevani, AnalĂa Silvina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Giordano, Mirta Nilda. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Galletti, JeremĂas GastĂłn. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin
Trophoblast cells inhibit neutrophil extracellular trap formation and enhance apoptosis through vasoactive intestinal peptide-mediated pathways
STUDY QUESTION:Do human trophoblast cells modulate neutrophil extracellular trap (NET) formation, reactive oxygen species (ROS) synthesis and neutrophil apoptosis through mechanisms involving vasoactive intestinal peptide (VIP)?SUMMARY ANSWER:Trophoblast cells inhibited NET formation and ROS synthesis and enhanced neutrophil apoptosis through VIP-mediated pathways in a model of maternal-placental interaction.WHAT IS KNOWN ALREADY:Immune homeostasis maintenance at the maternal-placental interface is mostly coordinated by trophoblast cells. Neutrophil activation and NET formation increases in pregnancies complicated by exacerbated pro-inflammatory responses. VIP has anti-inflammatory and immunosuppressant effects and is synthesized by trophoblast cells.STUDY DESIGN, SIZE, DURATION:This is a laboratory-based observational study that sampled circulating neutrophils from 50 healthy volunteers to explore their response in vitro to factors derived from human trophoblast cells.PARTICIPANTS/MATERIALS, SETTING, METHODS:Peripheral blood neutrophils were isolated from healthy volunteers and tested in vitro with first trimester trophoblast cell line (Swan-71 and HTR8) conditioned media (CM) or with VIP. The effect of VIP and trophoblast CM on NET formation was assessed by co-localization of elastase and DNA by confocal microscopy, DNA release and elastase activity measurement. Neutrophil apoptosis was determined by flow cytometry or fluorescence microscopy. ROS formation was assessed by flow cytometry with a fluorescent probe. VIP silencing was performed by siRNA transfection. For phagocytosis of apoptotic neutrophils, autologous monocytes were sampled, and engulfment and cytokines were assessed by flow cytometry and ELISA.MAIN RESULTS AND THE ROLE OF CHANCE:Trophoblast CM and 10 nM VIP promoted neutrophil deactivation by preventing phorbol myristate acetate-induced NET formation and ROS synthesis while they increased neutrophil spontaneous apoptosis and reversed the anti-apoptotic effect of lipopolysaccharide (all P < 0.05 versus control). The effects of trophoblast CM were prevented by a VIP antagonist or when VIP knocked-down trophoblast cells were used (P < 0.05 versus control). Neutrophils driven to apoptosis by trophoblast CM could be rapidly engulfed by monocytes without increasing IL-12 production.LARGE SCALE DATA:Not applicable.LIMITATIONS, REASONS FOR CAUTION:The mechanisms of neutrophil deactivation by trophoblast VIP are based on the results obtained with neutrophils drawn from peripheral blood of healthy individuals interacting with trophoblast cell lines in vitro. These studies were designed to investigate biological processes at the cellular and molecular level; therefore, they have the limitations of studies in vitro and it is not possible to ascertain if these mechanisms operate similarly in vivo. We tested 50 neutrophil samples from healthy volunteers that have a normal variability in their responses. Cell lines derived from human trophoblast were used, and we cannot rule out a differential behavior of trophoblast cells in contact with neutrophils in vivo.WIDER IMPLICATIONS OF THE FINDINGS:Results presented here are consistent with an active mechanism through which neutrophils in contact with trophoblast cells would be deactivated and silently cleared by decidual macrophages throughout pregnancy. They support a novel immunomodulatory role of trophoblast VIP on neutrophils at the placenta, providing new clues for pharmacological targeting of immune and trophoblast cells in pregnancy complications associated with exacerbated inflammation.Fil: Calo, Guillermina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Sabbione, Florencia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Vota, Daiana Marina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Paparini, Daniel Esteban. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Ramhorst, Rosanna Elizabeth. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Trevani, AnalĂa Silvina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Perez Leiros, Claudia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; Argentin
Neutrophil extracellular traps stimulate proinflammatory responses in human airway epithelial cells
Tissue injury leads to the release of uric acid (UA). At high local concentrations, UA can form monosodium urate crystals (MSU). MSU and UA stimulate neutrophils to release extracellular traps (NET). Here, we investigated whether these NET could be involved in the development of inflammation by stimulating cytokine release by airway epithelial cells. We found that NET significantly increased the secretion of CXCL8/IL-8 and IL-6 by alveolar and bronchial epithelial cells. These effects were not observed when NETosis was inhibited by Diphenyleneiodonium, elastase inhibitor, or Cl-amidine. Similar findings were made with NET induced by cigarette smoke extract, suggesting that NET proinflammatory capacity is independent of the inducing stimulus. Furthermore, NET affected neither the viability and morphology of epithelial cells nor the barrier integrity of polarized cells. The epithelial stimulatory capacity of NET was not affected by degradation of DNA with micrococcal nuclease, treatment with heparin, or inhibition of the elastase immobilized to DNA, but it was significantly reduced by pretreatment with an anti-HMGB-1 blocking antibody. Altogether, our findings indicate that NET exert direct proinflammatory effects on airway epithelial cells that might contribute in vivo to the further recruitment of neutrophils and the perpetuation of inflammation upon lung tissue damage.Instituto de Estudios InmunolĂłgicos y FisiopatolĂłgico
Protein A Modulates Neutrophil and Keratinocyte Signaling and Survival in Response to Staphylococcus aureus
The type 1 TNF-α receptor (TNFR1) has a central role in initiating both pro-inflammatory and pro-apoptotic signaling cascades in neutrophils. Considering that TNFR1 signals Staphylococcus aureus protein A (SpA), the aim of this study was to explore the interaction of this bacterial surface protein with neutrophils and keratinocytes to underscore the signaling pathways that may determine the fate of these innate immune cells in the infected tissue during staphylococcal skin infections. Using human neutrophils cultured in vitro and isogenic staphylococcal strains expressing or not protein A, we demonstrated that SpA is a potent inducer of IL-8 in neutrophils and that the induction of this chemokine is dependent on the SpA-TNFR1 interaction and p38 activation. In addition to IL-8, protein A induced the expression of TNF-α and MIP-1α highlighting the importance of SpA in the amplification of the inflammatory response. Protein A contributed to reduce neutrophil mortality prolonging their lifespan upon the encounter with S. aureus. Signaling initiated by SpA modulated the type of neutrophil cell death in vitro and during skin and soft tissue infections (SSTI) in vivo triggering the apoptotic pathway instead of necrosis. Moreover, SpA induced pro-inflammatory cytokines in keratinocytes, modulating their survival in vitro and preventing the exacerbated necrosis and ulceration of the epithelium during SSTI in vivo. Taken together, these results highlight the importance of the inflammatory signaling induced by protein A in neutrophils and skin epithelial cells. The ability of protein A to modulate the neutrophil/epithelial cell death program in the skin is of clinical relevance considering that lysis of neutrophils and epithelial cells will promote an intense inflammatory response and contribute to tissue damage, a non-desirable feature of complicated SSTI.Fil: Ledo, Camila. Universidad MaimĂłnides. Ărea de Investigaciones BiomĂ©dicas y BiotecnolĂłgicas. Centro de Estudios BiomĂ©dicos, BiotecnolĂłgicos, Ambientales y de DiagnĂłstico. Departamento de Estudios BiomĂ©dicos y BiotecnolĂłgicos; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Gonzalez, Cintia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de Investigaciones en MicrobiologĂa y ParasitologĂa MĂ©dica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en MicrobiologĂa y ParasitologĂa MĂ©dica; ArgentinaFil: Garofalo, Ailin Natalia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de Investigaciones en MicrobiologĂa y ParasitologĂa MĂ©dica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en MicrobiologĂa y ParasitologĂa MĂ©dica; ArgentinaFil: Sabbione, Florencia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Keitelman, Irene AngĂ©lica. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Giai, Constanza. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de Investigaciones en MicrobiologĂa y ParasitologĂa MĂ©dica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en MicrobiologĂa y ParasitologĂa MĂ©dica; ArgentinaFil: Stella, InĂ©s Yolanda. Universidad MaimĂłnides; ArgentinaFil: Trevani, AnalĂa Silvina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Gomez, Marisa Ines. Universidad MaimĂłnides. Ărea de Investigaciones BiomĂ©dicas y BiotecnolĂłgicas. Centro de Estudios BiomĂ©dicos, BiotecnolĂłgicos, Ambientales y de DiagnĂłstico. Departamento de Estudios BiomĂ©dicos y BiotecnolĂłgicos; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de Investigaciones en MicrobiologĂa y ParasitologĂa MĂ©dica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en MicrobiologĂa y ParasitologĂa MĂ©dica; Argentin
Neutrophil Extracellular Traps Stimulate Proinflammatory Responses in Human Airway Epithelial Cells
Tissue injury leads to the release of uric acid (UA). At high local concentrations, UA can form monosodium urate crystals (MSU). MSU and UA stimulate neutrophils to release extracellular traps (NET). Here, we investigated whether these NET could be involved in the development of inflammation by stimulating cytokine release by airway epithelial cells. We found that NET significantly increased the secretion of CXCL8/IL-8 and IL-6 by alveolar and bronchial epithelial cells. These effects were not observed when NETosis was inhibited by Diphenyleneiodonium, elastase inhibitor, or Cl-amidine. Similar findings were made with NET induced by cigarette smoke extract, suggesting that NET proinflammatory capacity is independent of the inducing stimulus. Furthermore, NET affected neither the viability and morphology of epithelial cells nor the barrier integrity of polarized cells. The epithelial stimulatory capacity of NET was not affected by degradation of DNA with micrococcal nuclease, treatment with heparin, or inhibition of the elastase immobilized to DNA, but it was significantly reduced by pretreatment with an anti-HMGB-1 blocking antibody. Altogether, our findings indicate that NET exert direct proinflammatory effects on airway epithelial cells that might contribute in vivo to the further recruitment of neutrophils and the perpetuation of inflammation upon lung tissue damage.Fil: Sabbione, Florencia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Keitelman, Irene AngĂ©lica. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Iula, Leonardo Jairo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Ferrero, Mariana Cristina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Giordano, Mirta Nilda. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de MicrobiologĂa, InmunologĂa y BiotecnologĂa; ArgentinaFil: Baldi, Pablo Cesar. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Rumbo, MartĂn. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de Estudios InmunolĂłgicos y FisiopatolĂłgicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios InmunolĂłgicos y FisiopatolĂłgicos; ArgentinaFil: Jancic, Carolina Cristina. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de MicrobiologĂa, InmunologĂa y BiotecnologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Trevani, AnalĂa Silvina. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de MicrobiologĂa, InmunologĂa y BiotecnologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin
Transient tear hyperosmolarity disrupts the neuroimmune homeostasis of the ocular surface and facilitates dry eye onset
Dry eye disease (DED) is a highly prevalent ocular surface disorder with neuroimmune pathophysiology. Tear hyperosmolarity (THO), a frequent finding in affected patients, is considered a key element in DED pathogenesis, yet existing animal models are based on subjecting the ocular surface to the more complex desiccating stress â decreased tear production and/or increased evaporation â instead of strict hyperosmolar stress. Here we characterized a murine model of THO that does not involve desiccating stress, thus allowing us to dissect the contribution of THO to DED. Our results showed that THO is sufficient to disrupt neuroimmune homeostasis of the ocular surface in mice, and thus reproduce many subâclinical DED findings. THO activated nuclear factorâÎșB signalling in conjunctival epithelial cells and increased dendritic cell recruitment and maturation, leading to more activated (CD69+) and memory (CD62lo CD44hi) CD4+ Tâcells in the eyeâdraining lymph nodes. Ultimately, THO impaired the development of ocular mucosal tolerance to a topical surrogate antigen in a chain of events that included epithelial nuclear factorâÎșB signalling and activation of transient receptor potential vanilloid 1 as the probable hypertonicity sensor. Also, THO reduced the density of corneal intraepithelial nerves and terminals, and sensitized the ocular surface to hypertonicity. Finally, the adoptive transfer of Tâcells from THO mice to naĂŻve recipients under mild desiccating stress favoured DED development, showing that THO is enough to trigger an actual pathogenic Tâcell response. Our results altogether demonstrate that THO is a critical initiating factor in DED development.Fil: GuzmĂĄn Fonseca, Oscar Mauricio. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Miglio RodrĂguez, Maximiliano Sebastian. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Keitelman, Irene AngĂ©lica. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Shiromizu, Carolina Maiumi. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Sabbione, Florencia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Fuentes, Federico. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Trevani, AnalĂa Silvina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Giordano, Mirta Nilda. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Galletti, JeremĂas GastĂłn. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin
Neutrophil extracellular traps stimulate proinflammatory responses in human airway epithelial cells
Tissue injury leads to the release of uric acid (UA). At high local concentrations, UA can form monosodium urate crystals (MSU). MSU and UA stimulate neutrophils to release extracellular traps (NET). Here, we investigated whether these NET could be involved in the development of inflammation by stimulating cytokine release by airway epithelial cells. We found that NET significantly increased the secretion of CXCL8/IL-8 and IL-6 by alveolar and bronchial epithelial cells. These effects were not observed when NETosis was inhibited by Diphenyleneiodonium, elastase inhibitor, or Cl-amidine. Similar findings were made with NET induced by cigarette smoke extract, suggesting that NET proinflammatory capacity is independent of the inducing stimulus. Furthermore, NET affected neither the viability and morphology of epithelial cells nor the barrier integrity of polarized cells. The epithelial stimulatory capacity of NET was not affected by degradation of DNA with micrococcal nuclease, treatment with heparin, or inhibition of the elastase immobilized to DNA, but it was significantly reduced by pretreatment with an anti-HMGB-1 blocking antibody. Altogether, our findings indicate that NET exert direct proinflammatory effects on airway epithelial cells that might contribute in vivo to the further recruitment of neutrophils and the perpetuation of inflammation upon lung tissue damage.Instituto de Estudios InmunolĂłgicos y FisiopatolĂłgico
Neutrophils from chronic lymphocytic leukemia patients exhibit an increased capacity to release extracellular traps (NETs)
Chronic lymphocytic leukemia (CLL) is characterized by immune defects that contribute to a high rate of infections and autoimmune cytopenias. Neutrophils are the first line of innate immunity and respond to pathogens through multiple mechanisms, including the release of neutrophil extracellular traps (NETs). These web-like structures composed of DNA, histones, and granular proteins are also produced under sterile conditions and play important roles in thrombosis and autoimmune disorders. Here we show that neutrophils from CLL patients are more prone to release NETs compared to those from age-matched healthy donors (HD). Increased generation of NETs was not due to higher levels of elastase, myeloperoxidase, or reactive oxygen species production. Instead, we found that plasma from CLL patients was able to prime neutrophils from HD to generate higher amounts of NETs upon activation. Plasmatic IL-8 was involved in the priming effect since its depletion reduced plasma capacity to enhance NETs release. Finally, we found that culture with NETs delayed spontaneous apoptosis and increased the expression of activation markers on leukemic B cells. Our study provides new insights into the immune dysregulation in CLL and suggests that the chronic inflammatory environment typical of CLL probably underlies this inappropriate neutrophil priming.Fil: Podaza, Enrique Arturo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Sabbione, Florencia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Risnik, Denise Mariel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Borge, Mercedes. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: AlmejĂșn, MarĂa BelĂ©n. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de FisiologĂa, BiologĂa Molecular y Celular; ArgentinaFil: Colado, Ana. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: FernĂĄndez Grecco, Horacio. Servicio de HematologĂa, Sanatorio Municipal Dr. Julio MĂ©ndez; ArgentinaFil: Cabrejo, MarĂa del Rosario. Servicio de HematologĂa, Sanatorio Municipal Dr. Julio MĂ©ndez; ArgentinaFil: Bezares, Raimundo F.. Servicio de HematologĂa, Hospital Municipal Dr. Teodoro Alvarez; ArgentinaFil: Trevani, AnalĂa Silvina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina; ArgentinaFil: Gamberale, Romina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Giordano, Mirta Nilda. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin
Neutrophil autophagy during human active tuberculosis is modulated by SLAMF1
Neutrophils infected with Mycobacterium tuberculosis (Mtb) predominate in tuberculosis patientsâ lungs. Neutrophils phagocytose the pathogen, but the mechanism of pathogen elimination is controversial. Macroautophagy/autophagy, a crucial mechanism for several neutrophil functions, can be modulated by immunological mediators. The costimulatory molecule SLAMF1 can act as a microbial sensor in macrophages being also able to interact with autophagy-related proteins. Here, we demonstrate for the first time that human neutrophils express SLAMF1 upon Mtb-stimulation. Furthermore, SLAMF1 was found colocalizing with LC3B+ vesicles, and activation of SLAMF1 increased neutrophil autophagy induced by Mtb. Finally, tuberculosis patientsâ neutrophils displayed reduced levels of SLAMF1 and lower levels of autophagy against Mtb as compared to healthy controls. Altogether, these results indicate that SLAMF1 participates in neutrophil autophagy during active tuberculosis.Fil: Pellegrini, JoaquĂn Miguel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Sabbione, Florencia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Morelli, MarĂa Paula. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Tateosian, Nancy Liliana. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Castello, Florencia Andrea. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Amiano, NicolĂĄs Oscar. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Palmero, Domingo Juan. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Levi, Alberto. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Ciallella, Lorena. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Colombo, Maria Isabel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Trevani, AnalĂa Silvina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: GarcĂa, VerĂłnica Edith. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; Argentin