RESUMO
Leishmaniasis is a neglected tropical disease that causes several clinical manifestations. Parasites of the genus Leishmania cause this disease. Spread across five continents, leishmaniasis is a particular public health problem in developing countries. Leishmania infects phagocytic cells such as macrophages, where it induces adenosine triphosphate (ATP) release at the time of infection. ATP activates purinergic receptors in the cell membranes of infected cells and promotes parasite control by inducing leukotriene B4 release and NLRP3 inflammasome activation. Moreover, uridine triphosphate induces ATP release, exacerbating the immune response. However, ATP may also undergo catalysis by ectonucleotidases present in the parasite membrane, generating adenosine, which activates P1 receptors and induces the production of anti-inflammatory molecules such as prostaglandin E2 and IL-10. These mechanisms culminate in Leishmania's survival. Thus, how Leishmania handles extracellular nucleotides and the activation of purinergic receptors determines the control or the dissemination of the disease.
Assuntos
Leishmania , Leishmaniose , Receptores Purinérgicos , Adenosina , Trifosfato de Adenosina , Dinoprostona/imunologia , Humanos , Interleucina-10/imunologia , Leishmania/fisiologia , Leishmaniose/imunologia , Leucotrieno B4/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Receptores Purinérgicos/metabolismo , Transdução de SinaisRESUMO
OBJECTIVE AND DESIGN: This study tested the hypothesis that sickle red blood cell (SS-RBC) can induce inflammasome NLRP3 components gene expression in peripheral blood mononuclear cells (PBMCs) as well as interleukin-1ß (IL-1ß) and leukotriene B4 (LTB4) production. Additionally, we investigated the effect of hydroxyurea (HU) treatment in these inflammatory markers. METHODS: PBMCs from healthy donors (AA-PBMC) were challenged with intact and lysed RBCs from SCA patients (SS-RBC) and from healthy volunteers (AA-RBC). NLRP3, IL-1ß, IL-18 and Caspase-1 gene expression levels were assessed by quantitative PCR (qPCR). IL-1ß protein levels and LTB4 were measured by ELISA. RESULTS: We observed that lysed SS-RBC induced the expression of inflammasome NLRP3 components, but this increase was more prominent for CASP1 and IL18 expression levels. Moreover, we observed that intact SS-RBC induced higher production of IL-1ß and LTB4 than lysed SS-RBC. Although SCA patients treated with HU have a reduction in NLRP3 gene expression and LTB4 production, this treatment did not modulate the expression of other inflammasome components or IL-1ß production. CONCLUSIONS: Thus, our data suggest that caspase-1, IL-1ß and IL-18 may contribute to the inflammatory status observed in SCA and that HU treatment may not interfere in this inflammatory pathway.
Assuntos
Anemia Falciforme/imunologia , Antidrepanocíticos/uso terapêutico , Eritrócitos/imunologia , Inflamassomos/imunologia , Leucócitos Mononucleares/imunologia , Leucotrieno B4/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Adolescente , Anemia Falciforme/sangue , Anemia Falciforme/tratamento farmacológico , Antidrepanocíticos/farmacologia , Caspase 1/genética , Células Cultivadas , Criança , Humanos , Hidroxiureia/farmacologia , Hidroxiureia/uso terapêutico , Inflamassomos/genética , Interleucina-18/genética , Interleucina-18/imunologia , Interleucina-1beta/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/genéticaRESUMO
Leishmaniasis is a neglected tropical disease affecting millions of individuals worldwide. P2X7 receptor has been linked to the elimination of Leishmania amazonensis. Biological responses evoked by P2X7 receptor activation have been well-documented, including apoptosis, phagocytosis, cytokine release, such as IL-1ß. It was demonstrated that NLRP3 inflammasome activation and IL-1ß signaling participated in resistance against L. amazonensis. Furthermore, our group has shown that L. amazonensis elimination through P2X7 receptor activation depended on leukotriene B4 (LTB4) production and release. Therefore, we investigated whether L. amazonensis elimination by P2X7 receptor and LTB4 involved NLRP3 inflammasome activation and IL-1ß signaling. We showed that macrophages from NLRP3-/-, ASC-/-, Casp-1/11-/-, gp91phox-/- , and IL-1R-/- mice treated with ATP or LTB4 did not decrease parasitic load as was observed in WT mice. When ASC-/- macrophages were treated with exogenous IL-1ß, parasite killing was noted, however, we did not see parasitic load reduction in IL-1R-/- macrophages. Similarly, macrophages from P2X7 receptor-deficient mice treated with IL-1ß also showed decreased parasitic load. In addition, when we infected Casp-11-/- macrophages, neither ATP nor LTB4 were able to reduce parasitic load, and Casp-11-/- mice were more susceptible to L. amazonensis infection than were WT mice. Furthermore, P2X7-/- L. amazonensis-infected mice locally treated with exogenous LTB4 showed resistance to infection, characterized by lower parasite load and smaller lesions compared to untreated P2X7-/- mice. A similar observation was noted when infected P2X7-/- mice were treated with IL-1ß, i.e., lower parasite load and smaller lesions compared to P2X7-/- mice. These data suggested that L. amazonensis elimination mediated by P2X7 receptor and LTB4 was dependent on non-canonical NLRP3 inflammasome activation, ROS production, and IL-1ß signaling.
Assuntos
Inflamassomos/imunologia , Interleucina-1beta/imunologia , Leishmania/imunologia , Leishmaniose/imunologia , Leucotrieno B4/imunologia , Macrófagos/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Receptores Purinérgicos P2X7/imunologia , Transdução de Sinais/imunologia , Animais , Inflamassomos/genética , Interleucina-1beta/genética , Leishmaniose/genética , Leishmaniose/patologia , Leucotrieno B4/genética , Macrófagos/parasitologia , Camundongos , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Receptores Purinérgicos P2X7/genética , Transdução de Sinais/genéticaRESUMO
Tityus serrulatus sting causes thousands of deaths annually worldwide. T. serrulatus-envenomed victims exhibit local or systemic reaction that culminates in pulmonary oedema, potentially leading to death. However, the molecular mechanisms underlying T. serrulatus venom (TsV) activity remain unknown. Here we show that TsV triggers NLRP3 inflammasome activation via K(+) efflux. Mechanistically, TsV triggers lung-resident cells to release PGE2, which induces IL-1ß production via E prostanoid receptor 2/4-cAMP-PKA-NFκB-dependent mechanisms. IL-1ß/IL-1R actions account for oedema and neutrophil recruitment to the lungs, leading to TsV-induced mortality. Inflammasome activation triggers LTB4 production and further PGE2 via IL-1ß/IL-1R signalling. Activation of LTB4-BLT1/2 pathway decreases cAMP generation, controlling TsV-induced inflammation. Exogenous administration confirms LTB4 anti-inflammatory activity and abrogates TsV-induced mortality. These results suggest that the balance between LTB4 and PGE2 determines the amount of IL-1ß inflammasome-dependent release and the outcome of envenomation. We suggest COX1/2 inhibition as an effective therapeutic intervention for scorpion envenomation.
Assuntos
Proteínas de Transporte/genética , Dinoprostona/farmacologia , Interleucina-1beta/efeitos dos fármacos , Leucotrieno B4/farmacologia , Macrófagos Peritoneais/efeitos dos fármacos , Picadas de Escorpião/imunologia , Venenos de Escorpião/farmacologia , Animais , Araquidonato 5-Lipoxigenase/genética , Western Blotting , Proteínas de Transporte/imunologia , Celecoxib/farmacologia , AMP Cíclico/imunologia , Proteínas Quinases Dependentes de AMP Cíclico/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/imunologia , Inibidores de Ciclo-Oxigenase/farmacologia , Dinoprostona/imunologia , Técnicas In Vitro , Indóis/farmacologia , Indometacina/farmacologia , Inflamassomos/imunologia , Interleucina-1beta/imunologia , Leucotrieno B4/imunologia , Inibidores de Lipoxigenase/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos Peritoneais/imunologia , Camundongos , Camundongos Knockout , NF-kappa B/efeitos dos fármacos , NF-kappa B/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR , Fosfoproteínas , Antagonistas de Prostaglandina/farmacologia , Receptores de Prostaglandina E Subtipo EP2/efeitos dos fármacos , Receptores de Prostaglandina E Subtipo EP2/imunologia , Receptores de Prostaglandina E Subtipo EP4/efeitos dos fármacos , Receptores de Prostaglandina E Subtipo EP4/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Picadas de Escorpião/mortalidade , Escorpiões , Xantonas/farmacologiaRESUMO
This study aimed at establishing the immunological signature and an algorithm for clinical management of the different clinical stages of the HTLV-1-infection based on serum biomarkers. A panel of serum biomarkers was evaluated by four sets of innovative/non-conventional data analysis approaches in samples from 87 HTLV-1 patients: asymptomatic carriers (AC), putative HTLV-1 associated myelopathy/tropical spastic paraparesis (pHAM/TSP) and HAM/TSP. The analysis of cumulative curves and molecular signatures pointed out that HAM/TSP presented a pro-inflammatory profile mediated by CXCL10/LTB-4/IL-6/TNF-α/IFN-γ, counterbalanced by IL-4/IL-10. The analysis of biomarker networks showed that AC presented a strongly intertwined pro-inflammatory/regulatory net with IL-4/IL-10 playing a central role, while HAM/TSP exhibited overall immune response toward a predominant pro-inflammatory profile. At last, the classification and regression trees proposed for clinical practice allowed for the construction of an algorithm to discriminate AC, pHAM and HAM/TSP patients with the elected biomarkers: IFN-γ, TNF-α, IL-10, IL-6, IL-4 and CysLT. These findings reveal a complex interaction among chemokine/leukotriene/cytokine in HTLV-1 infection and suggest the use of the selected but combined biomarkers for the follow-up/diagnosis of disease morbidity of HTLV-1-infected individuals.
Assuntos
Biomarcadores/sangue , Infecções por HTLV-I/sangue , Mediadores da Inflamação/sangue , Paraparesia Espástica Tropical/sangue , Adulto , Idoso , Western Blotting , Quimiocina CXCL10/sangue , Quimiocina CXCL10/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Infecções por HTLV-I/imunologia , Infecções por HTLV-I/virologia , Interações Hospedeiro-Patógeno/imunologia , Vírus Linfotrópico T Tipo 1 Humano/imunologia , Vírus Linfotrópico T Tipo 1 Humano/fisiologia , Humanos , Mediadores da Inflamação/imunologia , Interferon gama/sangue , Interferon gama/imunologia , Interleucina-10/sangue , Interleucina-10/imunologia , Interleucina-4/sangue , Interleucina-4/imunologia , Interleucina-6/sangue , Interleucina-6/imunologia , Leucotrieno B4/sangue , Leucotrieno B4/imunologia , Masculino , Pessoa de Meia-Idade , Paraparesia Espástica Tropical/imunologia , Paraparesia Espástica Tropical/virologia , Receptores de Leucotrienos/sangue , Receptores de Leucotrienos/imunologia , Transdução de Sinais/imunologia , Fator de Necrose Tumoral alfa/sangue , Fator de Necrose Tumoral alfa/imunologia , Adulto JovemRESUMO
BACKGROUND: Eicosanoids and sand fly saliva have a critical role in the Leishmania infection. Here, we evaluated the effect of Lutzomyia longipalpis salivary gland sonicate (SGS) on neutrophil and monocyte recruitment and activation of eicosanoid production in a murine model of inflammation. METHODS: C57BL/6 mice were inoculated intraperitonealy with Lutzomyia longipalpis SGS or Leishmania infantum or both, followed by analyses of cell recruitment, parasite load and eicosanoid production. RESULTS: Intraperitoneal injection of Lutzomyia longipalpis SGS together with Leishmania infantum induced an early increased parasite viability in monocytes and neutrophils. L. longipalpis SGS increased prostaglandin E2 (PGE2), but reduced leukotriene B4 (LTB4) production ex vivo in peritoneal leukocytes. In addition, the pharmacological inhibition of cyclooxygenase 2 (COX-2) with NS-398 decreased parasite viability inside macrophages during Leishmania infection in the presence of L. longipalpis SGS arguing that PGE2 production is associated with diminished parasite killing. CONCLUSIONS: These findings indicate that L. longipalpis SGS is a critical factor driving immune evasion of Leishmania through modulation of PGE2/LTB4 axis, which may represent an important mechanism on establishment of the infection.
Assuntos
Dinoprostona/imunologia , Leishmania infantum/imunologia , Leishmaniose Visceral/imunologia , Leucotrieno B4/imunologia , Psychodidae/imunologia , Animais , Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase/farmacologia , Modelos Animais de Doenças , Feminino , Humanos , Leishmaniose Visceral/parasitologia , Leucócitos/parasitologia , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nitrobenzenos/farmacologia , Psychodidae/parasitologia , Glândulas Salivares/imunologia , Sulfonamidas/farmacologiaRESUMO
The functions of phagocytic cells against pathogens are initiated by the interaction between membrane receptors and molecular structures which compose the cell wall of these microorganisms. Thus our study aimed to identify the neutrophil receptors involved in the recognition of different strains of Paracoccidioides brasiliensis and the consequent modulation of immune response through the production of cytokines and inflammatory mediators. Neutrophils did not produce TNF-alfa in response to both strains. However, these cells produce IL-12, mainly in response to Pb 265, with participation of TLR2 and dectin-1. These cells also produce L-10, whose levels were higher for Pb 18 with involvement of TLR2 and MR and only TLR2 for Pb 265. The production of PGE2 and LTB4 was detected similarly for the two strains. For PGE2, MR and dectin-1 were involved, while in relation to LTB4, none of them. In summary, we demonstrated that neutrophils have a dynamic role during host immune response to P. brasiliensis, since in addition to their role as effector cells of innate immunity; they have the capacity to modulate innate and adaptative immune response against this fungus by producing cytokines and lipidic mediators. This modulation may be toward a pró- or anti-inflammatory pattern in a dependence of P. brasiliensis strains and PRR involved in fungus recognition by these cells.
Assuntos
Lectinas Tipo C/imunologia , Lectinas de Ligação a Manose/imunologia , Neutrófilos/imunologia , Paracoccidioides/imunologia , Receptores de Superfície Celular/imunologia , Receptor 2 Toll-Like/imunologia , Células Cultivadas , Dinoprostona/biossíntese , Dinoprostona/imunologia , Humanos , Interleucina-10/biossíntese , Interleucina-10/imunologia , Interleucina-12/biossíntese , Interleucina-12/imunologia , Subunidade p35 da Interleucina-12 , Leucotrieno B4/biossíntese , Leucotrieno B4/imunologia , Receptor de Manose , Paracoccidioides/classificação , Paracoccidioidomicose/imunologia , Fator de Necrose Tumoral alfa/biossínteseRESUMO
High diesel exhaust particle levels are associated with increased health effects; however, knowledge on the impact of its chemical contaminant 1,2-naphthoquinone (1,2-NQ) is limited. We investigated whether postnatal and adult exposures to 1,2-NQ influence allergic reaction and the roles of innate and adaptive immunity. Male neonate (6 days) and adult (56 days) C57Bl/6 mice were exposed to 1,2-NQ (100 nM; 15 min) for 3 days, and on day 59, they were sensitized and later challenged with ovalbumin (OVA). Airway hyper-responsiveness (AHR) and production of cytokines, immunoglobulin E (IgE) and leukotriene B4 (LTB4) were measured in the airways. Postnatal exposure to 1,2-NQ activated dendritic cells in splenocytes by increasing expressing cell surface molecules (e.g., CD11c). Co-exposure to OVA effectively polarized T helper (Th) type 2 (Th2) by secreting Th2-mediated cytokines. Re-stimulation with unspecific stimuli (PMA and ionomycin) generated a mixed Th1 (CD4(+)/IFN-γ(+)) and Th17 (CD4(+)/IL-17(+)) phenotype in comparison with the vehicle-matched group. Postnatal exposure to 1,2-NQ did not induce eosinophilia in the airways at adulthood, although it evoked neutrophilia and exacerbated OVA-induced eosinophilia, Th2 cytokines, IgE and LTB4 production without affecting AHR and mast cell degranulation. At adulthood, 1,2-NQ exposure evoked neutrophilia and increased Th1/Th2 cytokine levels, but failed to affect OVA-induced eosinophilia. In conclusion, postnatal exposure to 1,2-NQ increases the susceptibility to antigen-induced asthma. The mechanism appears to be dependent on increased expression of co-stimulatory molecules, which leads to cell presentation amplification, Th2 polarization and enhanced LTB4, humoral response and Th1/Th2 cytokines. These findings may be useful for future investigations on treatments focused on pulmonary illnesses observed in children living in heavy polluted areas.
Assuntos
Envelhecimento/imunologia , Poluentes Atmosféricos/toxicidade , Exposição por Inalação/efeitos adversos , Naftoquinonas/toxicidade , Pneumonia/induzido quimicamente , Hipersensibilidade Respiratória/induzido quimicamente , Emissões de Veículos/toxicidade , Imunidade Adaptativa/efeitos dos fármacos , Envelhecimento/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Citocinas/imunologia , Suscetibilidade a Doenças/induzido quimicamente , Imunidade Inata/efeitos dos fármacos , Imunoglobulina E/imunologia , Exposição por Inalação/análise , Leucotrieno B4/imunologia , Masculino , Ovalbumina/imunologia , Pneumonia/imunologia , Hipersensibilidade Respiratória/imunologia , Emissões de Veículos/análiseRESUMO
Paracoccidioidomycosis is a human systemic mycosis caused by the fungus Paracoccidioides brasiliensis. The mechanisms involved in innate immune response to this fungus are not fully elucidated. Leukotrienes are known to be critical for the clearance of various microorganisms, mainly by mediating the microbicidal function of phagocytes. We investigated the involvement of leukotriene B4 in the early stages of experimental paracoccidioidomycosis, which was induced by intratracheal inoculation of the fungus in selected mouse lines. The mouse lines utilized were produced through bi-directional phenotypic selection, endowed with maximal or minimal acute inflammatory reactivity, and designated AIRmax and AIRmin, respectively. AIRmax mice were more resistant to the infection, which was demonstrated by reduced lung fungal loads. However, the two lines produced similar amounts of leukotriene B4, and pharmacological inhibition of this mediator provoked similar fungal load increases in the two lines. The lower fungal load in the AIRmax mice was associated with a more effective inflammatory response, which was characterized by enhanced recruitment and activation of phagocytic cells and an increased production of activator cytokines. This process resulted in an increased release of fungicidal molecules and a diminution of fungal load. In both lines, leukotriene production was associated with a protective response in the lung that was consequent to the effect of this eicosanoid on the influx and activation of phagocytes.
Assuntos
Interações Hospedeiro-Patógeno , Leucotrieno B4/imunologia , Paracoccidioides/imunologia , Paracoccidioidomicose/imunologia , Animais , Contagem de Colônia Microbiana , Modelos Animais de Doenças , Resistência à Doença , Pulmão/microbiologia , Masculino , Camundongos , FagocitoseRESUMO
OBJECTIVE: Deposition of monosodium urate monohydrate (MSU) crystals in the joints promotes an intense inflammatory response and joint dysfunction. This study evaluated the role of the NLRP3 inflammasome and 5-lipoxygenase (5-LOX)-derived leukotriene B(4) (LTB(4) ) in driving tissue inflammation and hypernociception in a murine model of gout. METHODS: Gout was induced by injecting MSU crystals into the joints of mice. Wild-type mice and mice deficient in NLRP3, ASC, caspase 1, interleukin-1ß (IL-1ß), IL-1 receptor type I (IL-1RI), IL-18R, myeloid differentiation factor 88 (MyD88), or 5-LOX were used. Evaluations were performed to assess neutrophil influx, LTB(4) activity, cytokine (IL-1ß, CXCL1) production (by enzyme-linked immunosorbent assay), synovial microvasculature cell adhesion (by intravital microscopy), and hypernociception. Cleaved caspase 1 and production of reactive oxygen species (ROS) were analyzed in macrophages by Western blotting and fluorometric assay, respectively. RESULTS: Injection of MSU crystals into the knee joints of mice induced neutrophil influx and neutrophil-dependent hypernociception. MSU crystal-induced neutrophil influx was CXCR2-dependent and relied on the induction of CXCL1 in an NLRP3/ASC/caspase 1/IL-1ß/MyD88-dependent manner. LTB(4) was produced rapidly after injection of MSU crystals, and this was necessary for caspase 1-dependent IL-1ß production and consequent release of CXCR2-acting chemokines in vivo. In vitro, macrophages produced LTB(4) after MSU crystal injection, and LTB(4) was relevant in the MSU crystal-induced maturation of IL-1ß. Mechanistically, LTB(4) drove MSU crystal-induced production of ROS and ROS-dependent activation of the NLRP3 inflammasome. CONCLUSION: These results reveal the role of the NLRP3 inflammasome in mediating MSU crystal-induced inflammation and dysfunction of the joints, and highlight a previously unrecognized role of LTB(4) in driving NLRP3 inflammasome activation in response to MSU crystals, both in vitro and in vivo.
Assuntos
Proteínas de Transporte/metabolismo , Gota/metabolismo , Hiperalgesia/metabolismo , Inflamassomos/metabolismo , Leucotrieno B4/metabolismo , Infiltração de Neutrófilos/fisiologia , Neutrófilos/metabolismo , Animais , Caspase 1/metabolismo , Citocinas/metabolismo , Gota/induzido quimicamente , Gota/imunologia , Hiperalgesia/imunologia , Inflamassomos/imunologia , Inflamação/imunologia , Inflamação/metabolismo , Interleucina-1beta/metabolismo , Leucotrieno B4/imunologia , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR , Neutrófilos/imunologia , Espécies Reativas de Oxigênio/metabolismo , Membrana Sinovial/imunologia , Membrana Sinovial/metabolismo , Ácido Úrico/farmacologiaRESUMO
Because of the potential protective role of leukotrienes (LTs) in histoplasmosis and the therapeutic and prophylactic effects of cell-free antigens from Histoplasmacapsulatum (CFAgs), the aim of this study was to develop and characterise biodegradable LTB(4)/CFAgs-loaded microspheres (MS) that could promote cellular activation for future immunisation purposes. LTB(4)/CFAgs-loaded MS that were developed through a double emulsion/extraction process were characterised according to their size, zeta potential, morphology, entrapment efficiency and in vitro release kinetics. We evaluated the uptake of LTB(4)/CFAgs-loaded MS by bone marrow derived-macrophages (BMDM). The TNF-α and chemokines, and nitrite production, in the supernatant of BMDM cultures were analysed by enzyme-linked immunosorbent assay (ELISA) and Griess reaction, respectively. We found an instantaneous release of CFAgs and a prolonged release of LTB(4) from the poly-(d,l-lactide-co-glycolide) (PLGA) MS. The microencapsulation process did not alter the zeta potential nor the spherical morphology of the MS. The appropriate size of the LTB(4)/CFAgs-loaded MS (smaller than 10µm) enabled the efficient uptake by BMDM and also induced TNF-α, CXCL1/KC, CCL2/MCP-1, CCL5/RANTES and nitrite oxide release by these cells. In conclusion, the biodegradable LTB(4)/CFAgs-loaded MS were able to efficiently activate murine BMDM and thereby have the potential to be used in an effective vaccine against H. capsulatum infection.
Assuntos
Antígenos de Fungos/imunologia , Histoplasma/imunologia , Leucotrieno B4/imunologia , Macrófagos/imunologia , Microesferas , Animais , Antígenos de Fungos/metabolismo , Células Cultivadas , Quimiocinas/imunologia , Histoplasma/metabolismo , Ácido Láctico , Leucotrieno B4/metabolismo , Macrófagos/metabolismo , Camundongos , Óxido Nítrico/imunologia , Ácido Poliglicólico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Fator de Necrose Tumoral alfa/imunologiaRESUMO
Candida albicans is the most common opportunistic fungal pathogen and causes local and systemic disease in immunocompromised patients. Alveolar macrophages (AMs) are pivotal for the clearance of C. albicans from the lung. Activated AMs secrete 5-lipoxygenase-derived leukotrienes (LTs), which in turn enhance phagocytosis and microbicidal activity against a diverse array of pathogens. Our aim was to investigate the role of LTB(4) and LTD(4) in AM antimicrobial functions against C. albicans and the signaling pathways involved. Pharmacologic and genetic inhibition of LT biosynthesis as well as receptor antagonism reduced phagocytosis of C. albicans when compared with untreated or WT controls. Conversely, exogenous LTs of both classes augmented base-line C. albicans phagocytosis by AMs. Although LTB(4) enhanced mainly mannose receptor-dependent fungal ingestion, LTD(4) enhanced mainly dectin-1 receptor-mediated phagocytosis. LT enhancement of yeast ingestion was dependent on protein kinase C-δ (PKCδ) and PI3K but not PKCα and MAPK activation. Both LTs reduced activation of cofilin-1, whereas they enhanced total cellular F-actin; however, LTB(4) accomplished this through the activation of LIM kinases (LIMKs) 1 and 2, whereas LTD(4) did so exclusively via LIMK-2. Finally, both exogenous LTB(4) and LTD(4) enhanced AM fungicidal activity in an NADPH oxidase-dependent manner. Our data identify LTB(4) and LTD(4) as key mediators of innate immunity against C. albicans, which act by both distinct and conserved signaling mechanisms to enhance multiple antimicrobial functions of AMs.
Assuntos
Actinas/metabolismo , Candida albicans/metabolismo , Candidíase/metabolismo , Cofilina 1/metabolismo , Imunidade Inata/fisiologia , Leucotrieno B4/metabolismo , Macrófagos Alveolares/metabolismo , Actinas/genética , Actinas/imunologia , Animais , Candida albicans/imunologia , Candidíase/genética , Candidíase/imunologia , Cofilina 1/genética , Cofilina 1/imunologia , Ativação Enzimática/genética , Ativação Enzimática/imunologia , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/imunologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Lectinas Tipo C , Leucotrieno B4/genética , Leucotrieno B4/imunologia , Quinases Lim/genética , Quinases Lim/imunologia , Quinases Lim/metabolismo , Macrófagos Alveolares/imunologia , Proteínas de Membrana/genética , Proteínas de Membrana/imunologia , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/imunologia , Proteínas do Tecido Nervoso/metabolismo , Fagocitose/genética , Fagocitose/imunologia , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/imunologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteína Quinase C-delta , Ratos , Ratos WistarRESUMO
Recent in vitro data have suggested that the flavonoid quercetin (1) does not affect the functioning of neutrophils. Therefore, we evaluated in vivo and in vitro whether or not 1 affects neutrophil function, focusing on recruitment. The in vivo treatment with 1 inhibited in a dose-dependent manner the recruitment of neutrophils to the peritoneal cavity of mice induced by known chemotatic factors such as CXCL1, CXCL5, LTB(4), and fMLP. Furthermore, 1 also inhibited in a concentration-dependent manner the chemoattraction of human neutrophils induced by CXCL8, LTB(4), and fMLP in a Boyden chamber. In vitro treatment with 1 did not affect human neutrophil surface expression of CXCR1, CXCR2, BLT1, or FLPR1, but rather reduced actin polymerization. These results suggest that 1 inhibits actin polymerization, hence, explaining the inhibition of neutrophil recruitment in vivo and in vitro and highlighting its possible usefulness to diminish excessive neutrophil migration during inflammation.
Assuntos
Actinas/metabolismo , Quimiocina CXCL5/imunologia , Interleucina-8/efeitos dos fármacos , Leucotrieno B4/imunologia , N-Formilmetionina Leucil-Fenilalanina/imunologia , Infiltração de Neutrófilos/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Quercetina/farmacologia , Actinas/efeitos dos fármacos , Animais , Fatores Quimiotáticos/imunologia , Quimiotaxia/imunologia , Relação Dose-Resposta a Droga , Humanos , Inflamação/imunologia , Interleucina-8/imunologia , Masculino , Camundongos , Estrutura Molecular , Infiltração de Neutrófilos/imunologia , Neutrófilos/imunologia , Quercetina/química , Quercetina/imunologiaRESUMO
Previously, we have shown that electroacupuncture (EA) in rats decreased eosinophil infiltration into the pulmonary tissue (PT) and in the bronchoalveolar lavage (BAL) in an experimental model of asthma. Th2 cytokines, leukotriene B4 (LTB4) and nitric oxide (NO) are involved in the asthma inflammatory process. The aim of this study was to verify the effects of EA on these asthma mediators. Male Wistar rats were divided into control (C), immobilized (I), sham acupuncture (SA), and acupuncture (A) groups. All rats were sensitized, and EA treatment using clinical acupuncture points was started 24h after antigen priming. EA was done every other day for 2weeks. Subsequently, animals were challenged by inhalation and sacrificed 24h later. At this time, the BAL and lungs were collected and used to analyze cytokine production, LTB4 and NO. The EA increased IL-1 and IFN-gamma and decreased IL-4, IL-10, NO and LTB4 in the BAL and PT compared to the C and SA groups. The presence of eosinophils in the BAL negatively correlated with IL-1 and IFN-gamma production and positively correlated with IL-4 and IL-10 production. Our results show that the beneficial anti-inflammatory action of EA on asthma is related to the balance of the Thl/Th2 response and the reduction of LTB4 and NO. These results suggest that EA therapy could be an important complementary treatment for asthma.
Assuntos
Asma/imunologia , Citocinas/imunologia , Eletroacupuntura , Inflamação/imunologia , Leucotrieno B4/imunologia , Óxido Nítrico/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Animais , Líquido da Lavagem Broncoalveolar/imunologia , Eosinófilos/imunologia , Humanos , Masculino , Ratos , Ratos Wistar , Células Th1/imunologia , Células Th2/imunologiaRESUMO
Herein, we investigated the involvement of the 5-LO-derived lipid mediator LTB(4) in gammadelta T cell migration. When injected into the i.pl. space of C57BL/6 mice, LTB(4) triggered gammadelta T lymphocyte mobilization in vivo, a phenomenon also observed in in vitro chemotaxis assays. The i.pl. injection of Escherichia coli endotoxin (LPS) triggered increased levels of LTB(4) in pleural cavities. The in vivo inhibition of LTB(4) biosynthesis by the 5-LO inhibitor zileuton or the FLAP inhibitor MK886 attenuated LPS-induced gammadelta T cell accumulation into pleural cavities. Accordingly, 5-LO KO mice failed to recruit gammadelta T cells into the inflammatory site after i.pl. LPS. Antagonists of the high-affinity LTB(4) receptor BLT1, CP105,696, and LY292476 also attenuated LPS-induced gammadelta T cell accumulation in pleural cavities as well as in vitro chemotaxis toward pleural washes obtained from LPS-simulated mice. LTB(4)/BLT1 also accounted for gammadelta T cell migration induced by i.pl. administration of Mycobacterium bovis BCG or antigen in sensitized mice. BLT1 was expressed on naïve, resident as well as LPS-recruited gammadelta T cells. Isolated gammadelta T cells were found to undergo F-actin cytoskeleton reorganization when incubated with LTB(4) in vitro, confirming that gammadelta T lymphocytes can respond directly to LTB(4). In addition to its direct effect on gammadelta T cells, LTB(4) triggered their accumulation indirectly, via modulation of CCL2 production in mouse pleural cavities. These data show that gammadelta T cell migration into the pleural cavity of mice during diverse inflammatory responses is dependent on LTB(4)/BLT1.
Assuntos
Araquidonato 5-Lipoxigenase/metabolismo , Movimento Celular , Leucotrieno B4/metabolismo , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Receptores do Leucotrieno B4/metabolismo , Linfócitos T/metabolismo , Actinas/genética , Actinas/imunologia , Actinas/metabolismo , Animais , Araquidonato 5-Lipoxigenase/genética , Araquidonato 5-Lipoxigenase/imunologia , Benzopiranos , Ácidos Carboxílicos , Quimiocina CCL2/genética , Quimiocina CCL2/imunologia , Quimiocina CCL2/metabolismo , Citoesqueleto/genética , Citoesqueleto/imunologia , Citoesqueleto/metabolismo , Inflamação/genética , Inflamação/imunologia , Inflamação/metabolismo , Leucotrieno B4/genética , Leucotrieno B4/imunologia , Lipopolissacarídeos/farmacologia , Camundongos , Camundongos Knockout , Mycobacterium bovis/genética , Mycobacterium bovis/imunologia , Mycobacterium bovis/metabolismo , Receptores de Antígenos de Linfócitos T gama-delta/genética , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Receptores do Leucotrieno B4/antagonistas & inibidores , Linfócitos T/imunologiaRESUMO
Histoplasmosis is a pulmonary disease characterised by chronic granulomatous and suppurative inflammatory reactions caused by Histoplasma capsulatum. Regarding new therapies to control fungal infections, the aim of this study was to investigate whether pulmonary administration of leukotriene B(4) (LTB(4))-loaded microspheres (MS) could confer protection to 5-lipoxygenase knockout (5-LO(-/-)) mice infected by H. capsulatum. In this study, MS containing LTB(4) were administered intranasally to mice infected by H. capsulatum. On Day 14 after the infection, fungal recovery from the lungs and histology were evaluated and inflammatory cytokines were measured. Pulmonary administration of LTB(4)-loaded MS was able to reduce fungal recovery from infected lungs. Production of important inflammatory cytokines related to host defence was augmented following MS administration to the lungs. Lung histology also showed that infected mice presented a clear reduction in the fungal burden following the pulmonary release of LTB(4) from MS. Our study provides evidence that the proposed biodegradable microparticulate system, which can release LTB(4) to the lungs, can be employed as therapy, enhancing the antimicrobial activity of host cells during histoplasmosis.
Assuntos
Histoplasma/efeitos dos fármacos , Histoplasmose , Leucotrieno B4/farmacologia , Microesferas , Administração Intranasal , Animais , Citocinas/imunologia , Citocinas/metabolismo , Glicolatos , Histoplasmose/tratamento farmacológico , Histoplasmose/imunologia , Histoplasmose/microbiologia , Histoplasmose/patologia , Humanos , Inflamação/tratamento farmacológico , Inflamação/imunologia , Inflamação/microbiologia , Ácido Láctico , Leucotrieno B4/administração & dosagem , Leucotrieno B4/imunologia , Lipoxigenase/genética , Pulmão/imunologia , Pulmão/microbiologia , Pulmão/patologia , Pneumopatias Fúngicas/tratamento farmacológico , Pneumopatias Fúngicas/imunologia , Pneumopatias Fúngicas/microbiologia , Pneumopatias Fúngicas/patologia , Masculino , Camundongos , Camundongos Knockout , Ácido Poliglicólico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Resultado do TratamentoRESUMO
The D-mannose binding lectin ArtinM from Artocarpus integrifolia, previously known as KM+ and artocarpin, is considered a stimulant of Th1-type immunity, which is able to confer resistance to some intracellular pathogens. In addition, ArtinM induces neutrophil migration by haptotaxis through simultaneous interactions of its carbohydrate recognition domains (CRDs) with glycans expressed on the extracellular matrix and the neutrophil surface. In the present study, we have expanded the characterization of ArtinM as a neutrophil activator. Exposure of neutrophils to ArtinM for 15 min resulted in tyrosine phosphorylation of intracellular proteins, a process that was selectively inhibited by d-mannose or mannotriose. Shortly after stimulation, neutrophils secreted high levels of LTB(4) and underwent shedding of L-selectin from their surface. Exposure to ArtinM enhanced neutrophil functions, such as respiratory burst and zymozan and Listeria monocytogenes phagocytosis. In addition, ArtinM-stimulated neutrophils displayed increased CXCL-8 secretion and TLR2 gene transcription. These results demonstrate that ArtinM is able to induce potent neutrophil activation, a feature that should be strongly considered in the assessment of the lectin capacity to confer resistance against infections.
Assuntos
Movimento Celular , Lectinas de Ligação a Manose/farmacologia , Ativação de Neutrófilo , Neutrófilos/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Lectinas de Plantas/farmacologia , Humanos , Interleucina-8/biossíntese , Interleucina-8/imunologia , Interleucina-8/farmacologia , Selectina L/efeitos dos fármacos , Selectina L/imunologia , Selectina L/metabolismo , Leucotrieno B4/biossíntese , Leucotrieno B4/imunologia , Neutrófilos/imunologia , Fagocitose/imunologia , Receptor 2 Toll-Like/efeitos dos fármacos , Receptor 2 Toll-Like/imunologia , Receptor 2 Toll-Like/metabolismoRESUMO
Histoplasma capsulatum (Hc) is a facultative, intracellular parasite of worldwide significance. Infection with Hc produces a broad spectrum of diseases and may progress to a life-threatening systemic disease, particularly in individuals with HIV infection. Resolution of histoplasmosis is associated with the activation of cell-mediated immunity, and leukotriene B(4) plays an important role in this event. Lipid bodies (LBs) are increasingly being recognized as multifunctional organelles with roles in inflammation and infection. In this study, we investigated LB formation in histoplasmosis and its putative function in innate immunity. LB formation in leukocytes harvested from Hc-infected C57BL/6 mice peaks on day 2 postinfection and correlates with enhanced generation of lipid mediators, including leukotriene B(4) and PGE(2). Pretreatment of leukocytes with platelet-activating factor and BLT1 receptor antagonists showed that both lipid mediators are involved in cell signaling for LB formation. Alveolar leukocytes cultured with live or dead Hc also presented an increase in LB numbers. The yeast alkali-insoluble fraction 1, which contains mainly beta-glucan isolated from the Hc cell wall, induced a dose- and time-dependent increase in LB numbers, indicating that beta-glucan plays a signaling role in LB formation. In agreement with this hypothesis, beta-glucan-elicited LB formation was inhibited in leukocytes from 5-LO(-/-), CD18(low) and TLR2(-/-) mice, as well as in leukocytes pretreated with anti-Dectin-1 Ab. Interestingly, human monocytes from HIV-1-infected patients failed to produce LBs after beta-glucan stimulation. These results demonstrate that Hc induces LB formation, an event correlated with eicosanoid production, and suggest a role for these lipid-enriched organelles in host defense during fungal infection.
Assuntos
Antígenos CD18/metabolismo , Infecções por HIV/imunologia , Histoplasmose/imunologia , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Organelas/imunologia , Receptor 2 Toll-Like/metabolismo , beta-Glucanas/imunologia , Adulto , Animais , Antígenos CD18/imunologia , Parede Celular/química , Parede Celular/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , HIV-1 , Histoplasma/imunologia , Humanos , Lectinas Tipo C , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Leucotrieno B4/biossíntese , Leucotrieno B4/imunologia , Lipídeos , Masculino , Proteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/imunologia , Organelas/metabolismo , Receptor 2 Toll-Like/imunologiaRESUMO
OBJECTIVE: To investigate the mechanism underlying neutrophil migration into the articular cavity in experimental arthritis and, by extension, human inflammatory synovitis. METHODS: Antigen-induced arthritis (AIA) was generated in mice with methylated bovine serum albumin (mBSA). Migration assays and histologic analysis were used to evaluate neutrophil recruitment to knee joints. Levels of inflammatory mediators were measured by enzyme-linked immunosorbent assay. Antibodies and pharmacologic inhibitors were used in vivo to determine the role of specific disease mediators. Samples of synovial tissue and synovial fluid from rheumatoid arthritis (RA) or osteoarthritis patients were evaluated for CXCL1 and CXCL5 expression. RESULTS: High levels of CXCL1, CXCL5, and leukotriene B4 (LTB4) were expressed in the joints of arthritic mice. Confirming their respective functional roles, repertaxin (a CXCR1/CXCR2 receptor antagonist), anti-CXCL1 antibody, anti-CXCL5 antibody, and MK886 (a leukotriene synthesis inhibitor) reduced mBSA-induced neutrophil migration to knee joints. Repertaxin reduced LTB4 production in joint tissue, and neutrophil recruitment induced by CXCL1 or CXCL5 was inhibited by MK886, suggesting a sequential mechanism. Levels of both CXCL1 and CXCL5 were elevated in synovial fluid and were released in vitro by RA synovial tissues. Moreover, RA synovial fluid neutrophils stimulated with CXCL1 or CXCL5 released significant amounts of LTB4. CONCLUSION: Our data implicate CXCL1, CXCL5, and LTB4, acting sequentially, in neutrophil migration in AIA. Elevated levels of CXCL1 and CXCL5 in the synovial compartment of RA patients provide robust comparative data indicating that this mechanism plays a role in inflammatory joint disease. Together, these results suggest that inhibition of CXCL1, CXCL5, or LTB4 may represent a potential therapeutic strategy in RA.
Assuntos
Artrite/imunologia , Quimiotaxia de Leucócito/imunologia , Leucotrieno B4/imunologia , Neutrófilos/imunologia , Receptores de Interleucina-8B/imunologia , Animais , Quimiocina CXCL1/imunologia , Quimiocina CXCL5/imunologia , Ensaio de Imunoadsorção Enzimática , Humanos , Articulação do Joelho/imunologia , Articulação do Joelho/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB CRESUMO
OBJECTIVE: We investigated the effect of intrauterine undernourishment on some features of asthma using a model of allergic lung inflammation in rats. The effects of age at which the rats were challenged (5 and 9 wk) were also evaluated. METHODS: Intrauterine undernourished offspring were obtained from dams that were fed 50% of the nourished diet of counterparts and were immunized at 5 and 9 wk of age. They were tested for immunoglobulin E anti-ova titers (by passive cutaneous anaphylaxis), cell count in the bronchoalveolar fluid, leukotriene concentration, airway reactivity, mucus production, and blood corticosterone and leptin concentrations 21 d after immunologic challenge. RESULTS: Intrauterine undernourishment significantly reduced the antigen-specific immunoglobulin E production, inflammatory cell infiltration into airways, mucus secretion, and production of leukotrienes B(4)/C(4) in the lungs in both age groups compared with respective nourished rats. The increased reactivity to methacholine that follows antigen challenge was not affected by intrauterine undernourishment. Corticosterone levels increased with age in the undernourished rats' offspring, but not in the nourished rats' offspring. Undernourished offspring already presented high levels of corticosterone before inflammatory stimulus and were not modified by antigen challenge. Leptin levels increased with challenge in the nourished rats but not in the undernourished rats and could not be related to corticosterone levels in the undernourished rats. CONCLUSION: Intrauterine undernourishment has a striking and age-dependent effect on the offspring, reducing lung allergic inflammation.