RESUMEN

Macrophages play a pivotal role in tissue homeostasis, pathogen defense, and inflammation resolution. M1 and M2 macrophage phenotypes represent two faces in a spectrum of responses to microenvironmental changes, crucial in both physiological and pathological conditions. Neuraminidase 1 (Neu1), a lysosomal and cell surface sialidase responsible for removing terminal sialic acid residues from glycoconjugates, modulates several macrophage functions, including phagocytosis and Toll-like receptor (TLR) signaling. Current evidence suggests that Neu1 expression influences M1/M2 macrophage phenotype alterations in the context of cardiovascular diseases, indicating a potential role for Neu1 in macrophage polarization. For this reason, we investigated the impact of Neu1 deficiency on macrophage polarization in vitro and in vivo. Using bone marrow-derived macrophages (BMDMs) and peritoneal macrophages from Neu1 knockout (Neu1-/- ) mice and wild-type (WT) littermate controls, we demonstrated that Neu1-deficient macrophages exhibit an aberrant M2-like phenotype, characterized by elevated macrophage mannose receptor 1 (MMR/CD206) expression and reduced responsiveness to M1 stimuli. This M2-like phenotype was also observed in vivo in peritoneal and splenic macrophages. However, lymph node (LN) macrophages from Neu1-/- mice exhibited phenotypic alterations with reduced CD206 expression. Further analysis revealed that peripheral LNs from Neu1-/- mice were highly fibrotic, with overexpression of transforming growth factor-beta 1 (TGF-ß1) and hyperactivated TGF-ß signaling in LN macrophages. Consistently, TGF-ß1 was found to alter M1/M2 macrophage polarization in vitro. Our findings showed that Neu1 deficiency prompts macrophages towards an M2 phenotype and that microenvironmental changes, particularly increased TGF-ß1 in fibrotic tissues such as peripheral LNs in Neu1-/- mice, further influence M1/M2 macrophage polarization, highlighting its sensitivity to the local microenvironment. Therapeutic interventions targeting Neu1 or TGF-ß signaling pathways may offer the potential to regulate macrophage behavior across different diseases.

Asunto(s)

Microambiente Celular , Fibrosis , Ganglios Linfáticos , Macrófagos , Ratones Noqueados , Neuraminidasa , Animales , Ratones , Macrófagos/inmunología , Macrófagos/metabolismo , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/metabolismo , Ganglios Linfáticos/patología , Neuraminidasa/deficiencia , Neuraminidasa/genética , Neuraminidasa/metabolismo , Ratones Endogámicos C57BL , Activación de Macrófagos , Lectinas Tipo C/metabolismo , Lectinas Tipo C/genética , Lectinas Tipo C/deficiencia , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/metabolismo , Células Cultivadas , Transducción de Señal , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Receptores de Superficie Celular/deficiencia , Receptor de Manosa , Fenotipo , Factor de Crecimiento Transformador beta1/metabolismo

RESUMEN

Leishmania donovani is a protozoan parasite that causes visceral leishmaniasis, provoking liver and spleen tissue destruction that is lethal unless treated. The parasite replicates in macrophages and modulates host microbicidal responses. We have previously reported that neutrophil elastase (NE) is required to sustain L. donovani intracellular growth in macrophages through the induction of interferon beta (IFN-ß). Here, we show that the gene expression of IFN-ß by infected macrophages was reduced by half when TLR4 was blocked by pre-treatment with neutralizing antibodies or in macrophages from tlr2-/- mice, while the levels in macrophages from myd88-/- mice were comparable to those from wild-type C57BL/6 mice. The neutralization of TLR4 in tlr2-/- macrophages completely abolished induction of IFN-ß gene expression upon parasite infection, indicating an additive role for both TLRs. Induction of type I interferon (IFN-I), OASL2, SOD1, and IL10 gene expression by L. donovani was completely abolished in macrophages from NE knock-out mice (ela2-/-) or from protein kinase R (PKR) knock-out mice (pkr-/-), and in C57BL/6 macrophages infected with transgenic L. donovani expressing the inhibitor of serine peptidase 2 (ISP2). Parasite intracellular growth was impaired in pkr-/- macrophages but was fully restored by the addition of exogenous IFN-ß, and parasite burdens were reduced in the spleen of pkr-/- mice at 7 days, as compared to the 129Sv/Ev background mice. Furthermore, parasites were unable to grow in macrophages lacking TLR3, which correlated with lack of IFN-I gene expression. Thus, L. donovani engages innate responses in infected macrophages via TLR2, TLR4, and TLR3, via downstream PKR, to induce the expression of pro-survival genes in the host cell, and guarantee parasite intracellular development.

Asunto(s)

Interferón-alfa/metabolismo , Interferón beta/metabolismo , Leishmania donovani/inmunología , Leishmaniasis Visceral/inmunología , Macrófagos Peritoneales/inmunología , Transducción de Señal/genética , Receptor Toll-Like 2/metabolismo , Receptor Toll-Like 3/metabolismo , Receptor Toll-Like 4/metabolismo , eIF-2 Quinasa/metabolismo , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/farmacología , Femenino , Expresión Génica , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/inmunología , Técnicas de Inactivación de Genes , Interferón-alfa/genética , Interferón beta/genética , Leishmaniasis Visceral/parasitología , Elastasa de Leucocito/antagonistas & inhibidores , Elastasa de Leucocito/genética , Elastasa de Leucocito/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Transducción de Señal/efectos de los fármacos , Transducción de Señal/inmunología , Sulfonamidas/farmacología , Receptor Toll-Like 2/genética , Receptor Toll-Like 3/genética , Receptor Toll-Like 4/antagonistas & inhibidores , Receptor Toll-Like 4/inmunología , eIF-2 Quinasa/genética

RESUMEN

BACKGROUND: Immunomodulatory therapies are claimed to enhance antimicrobial immunity and counterbalance antimicrobial resistance mechanisms of pathogenic bacteria. PURPOSE: To investigate whether caffeine can be useful for control of inflammation derived from experimental systemic infection with Listeria monocytogenes. METHODS: Peritoneal macrophages (pMØ) from Swiss mice were cultured with caffeine in 96-well plates, and then infected with virulent L. monocytogenes 619. In another experiment, the pMØ were first infected with the bacterium and then treated with caffeine. Swiss mice were inoculated intraperitoneally with L. monocytogenes and then treated intravenously with caffeine (0.05; 0.5 or 5 mg/Kg). RESULTS: Caffeine did not exert direct antibacterial activity in vitro against L. monocytogenes. Macrophages exposed to caffeine before or after infection with L. monocytogenes had increased cell viability, although the intracellular bacterial loads were similar to the control groups. Caffeine treatments of Swiss mice reduced leukocyte infiltration into the peritoneal cavity after L. monocytogenes infection. However, the bacterial burden was reduced in the spleen and liver. The mRNA expressions of IL-1ß, IL-6 and the enzyme inducible nitric oxide synthase (iNOS) were reduced whereas IL-10 was increased. CONCLUSION: Caffeine has an anti-infectious potential and ameliorated infection-derived inflammation following experimental infection with L. monocytogenes.

Asunto(s)

Antiinflamatorios/farmacología , Cafeína/farmacología , Inflamación/tratamiento farmacológico , Listeria monocytogenes/patogenicidad , Listeriosis/tratamiento farmacológico , Macrófagos Peritoneales/efectos de los fármacos , Animales , Cafeína/análogos & derivados , Células Cultivadas , Quimiotaxis de Leucocito/efectos de los fármacos , Modelos Animales de Enfermedad , Interacciones Huésped-Patógeno , Inflamación/inmunología , Inflamación/metabolismo , Inflamación/microbiología , Mediadores de Inflamación/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Listeria monocytogenes/inmunología , Listeriosis/inmunología , Listeriosis/metabolismo , Listeriosis/microbiología , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/metabolismo , Macrófagos Peritoneales/microbiología , Ratones , Óxido Nítrico Sintasa de Tipo II/genética , Óxido Nítrico Sintasa de Tipo II/metabolismo , Virulencia

RESUMEN

Chagas disease is a life-threatening disorder caused by the protozoan parasite Trypanosoma cruzi. Parasite-specific antibodies, CD8+ T cells, as well as IFN-γ and nitric oxide (NO) are key elements of the adaptive and innate immunity against the extracellular and intracellular forms of the parasite. Bim is a potent pro-apoptotic member of the Bcl-2 family implicated in different aspects of the immune regulation, such as negative selection of self-reactive thymocytes and elimination of antigen-specific T cells at the end of an immune response. Interestingly, the role of Bim during infections remains largely unidentified. To explore the role of Bim in Chagas disease, we infected WT, Bim+/-, Bim-/- mice with trypomastigotes forms of the Y strain of T. cruzi. Strikingly, our data revealed that Bim-/- mice exhibit a delay in the development of parasitemia followed by a deficiency in the control of parasite load in the bloodstream and a decreased survival compared to WT and Bim+/- mice. At the peak of parasitemia, peritoneal macrophages of Bim-/- mice exhibit decreased NO production, which correlated with a decrease in the pro-inflammatory Small Peritoneal Macrophage (SPM) subset. A similar reduction in NO secretion, as well as in the pro-inflammatory cytokines IFN-γ and IL-6, was also observed in Bim-/- splenocytes. Moreover, an impaired anti-T. cruzi CD8+ T-cell response was found in Bim-/- mice at this time point. Taken together, our results suggest that these alterations may contribute to the establishment of a delayed yet enlarged parasitic load observed at day 9 after infection of Bim-/- mice and place Bim as an important protein in the control of T. cruzi infections.

Asunto(s)

Proteína 11 Similar a Bcl2/deficiencia , Enfermedad de Chagas/parasitología , Trypanosoma cruzi/patogenicidad , Animales , Proteína 11 Similar a Bcl2/genética , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Linfocitos T CD8-positivos/parasitología , Células Cultivadas , Enfermedad de Chagas/genética , Enfermedad de Chagas/inmunología , Enfermedad de Chagas/metabolismo , Modelos Animales de Enfermedad , Femenino , Interacciones Huésped-Parásitos , Interferón gamma/metabolismo , Interleucina-6/metabolismo , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/metabolismo , Macrófagos Peritoneales/parasitología , Ratones Endogámicos C57BL , Ratones Noqueados , Óxido Nítrico/metabolismo , Carga de Parásitos , Bazo/inmunología , Bazo/metabolismo , Bazo/parasitología , Factores de Tiempo , Trypanosoma cruzi/inmunología

RESUMEN

Chagas disease, caused by the parasite Trypanosoma cruzi, is considered endemic in more than 20 countries but lacks both an approved vaccine and limited treatment for its chronic stage. Chronic infection is most harmful to human health because of long-term parasitic infection of the heart. Here we show that immunization with a virus-like particle vaccine displaying a high density of the immunogenic α-Gal trisaccharide (Qß-αGal) induced several beneficial effects concerning acute and chronic T. cruzi infection in α1,3-galactosyltransferase knockout mice. Approximately 60% of these animals were protected from initial infection with high parasite loads. Vaccinated animals also produced high anti-αGal IgG antibody titers, improved IFN-γ and IL-12 cytokine production, and controlled parasitemia in the acute phase at 8 days post-infection (dpi) for the Y strain and 22 dpi for the Colombian strain. In the chronic stage of infection (36 and 190 dpi, respectively), all of the vaccinated group survived, showing significantly decreased heart inflammation and clearance of amastigote nests from the heart tissue.

Asunto(s)

Cardiomiopatía Chagásica/prevención & control , Corazón/parasitología , Vacunas Antiprotozoos/inmunología , Trypanosoma cruzi , Animales , Anticuerpos Antiprotozoarios/sangre , Cardiomiopatía Chagásica/parasitología , Cardiomiopatía Chagásica/patología , Citocinas/genética , Citocinas/metabolismo , Femenino , Regulación de la Expresión Génica/inmunología , Inmunoglobulina G/sangre , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/metabolismo , Macrófagos Peritoneales/parasitología , Ratones , Ratones Endogámicos C57BL , Parasitemia , Receptor Toll-Like 2/genética , Receptor Toll-Like 2/metabolismo , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/metabolismo

RESUMEN

Histoplasma capsulatum is the causative agent of histoplasmosis, a systemic disease responsible for most reported causes of morbidity and mortality among immunosuppressed individuals. Peptidogalactomannan (pGM) was purified from the yeast cell wall of H. capsulatum isolated from bats, and its structure and involvement in modulating the host immune response were evaluated. Gas chromatography, methylation analysis, and two-dimensional nuclear magnetic resonance (2D-NMR) were used for the structural characterization of pGM. Methylation and 2D-NMR data revealed that pGM comprises a main chain containing α-D-Manp (1 → 6) residues substituted at O-2 by α-D-Manp (1 → 2)-linked side chains, non-reducing end units of α-D-Galf, or ß-D-Galp linked (1→ 6) to α-D-Manp side chains. The involvement of H. capsulatum pGM in antigenic reactivity and in interactions with macrophages was demonstrated by ELISA and phagocytosis assay, respectively. The importance of the carbohydrate and protein moieties of pGM in sera reactivity was evaluated. Periodate oxidation abolished much pGM antigenic reactivity, suggesting that the sugar moiety is the most immunogenic part of pGM. Reactivity slightly decreased in pGM treated with proteinase K, suggesting that the peptide moiety plays a minor role in pGM antigenicity. In vitro experiments suggested that pGM is involved in the phagocytosis of H. capsulatum yeast and induction of IL-10 and IFN-γ secretion by peritoneal macrophages from C57BL/6 mice. These findings demonstrated the role of pGM in the H. capsulatum-host interaction.

Asunto(s)

Glicopéptidos/química , Glicopéptidos/farmacología , Histoplasma/química , Histoplasmosis/microbiología , Macrófagos Peritoneales/efectos de los fármacos , Mananos/química , Mananos/farmacología , Animales , Pared Celular/química , Pared Celular/inmunología , Quirópteros/microbiología , Femenino , Galactosa/análogos & derivados , Histoplasma/inmunología , Histoplasma/aislamiento & purificación , Histoplasmosis/genética , Histoplasmosis/inmunología , Humanos , Interferón gamma/genética , Interferón gamma/inmunología , Interleucina-10/genética , Interleucina-10/inmunología , Macrófagos Peritoneales/inmunología , Masculino , Espectrometría de Masas , Ratones , Ratones Endogámicos C57BL , Fagocitosis/efectos de los fármacos , Conejos

RESUMEN

BACKGROUND: Anti-inflammatory properties have been attributed to latex proteins of the medicinal plant Calotropis procera. PURPOSE: A mixture of cysteine peptidases (LPp2) from C. procera latex was investigated for control of inflammatory mediators and inflammation in a mouse model of Salmonella infection. METHODS: LPp2 peptidase activity was confirmed by the BANA assay. Cytotoxicity assays were conducted with immortalized macrophages. Peritoneal macrophages (pMØ) from Swiss mice were stimulated with lipopolysaccharide (LPS) in 96-well plates and then cultured with nontoxic concentrations of LPp2. Swiss mice intravenously received LPp2 (10 mg/kg) and then were challenged intraperitoneally with virulent Salmonella enterica Ser. Typhimurium. RESULTS: LPp2 was not toxic at dosages lower than 62.2 µg/mL. LPp2 treatments of pMØ stimulated with LPS impaired mRNA expression of pro-inflammatory cytokines IL-1ß, TNF-α, IL-6 and IL-10. LPp2 increased the intracellular bacterial killing in infected pMØ. Mice given LPp2 had a lower number of leukocytes in the peritoneal cavity in comparison to control groups 6 h after infection. The bacterial burden and histological damage were widespread in target organs of mice receiving LPp2. CONCLUSION: We conclude that LPp2 contains peptidases with strong anti-inflammatory properties, which may render mice more susceptible to early disseminated infection caused by Salmonella.

Asunto(s)

Antiinflamatorios/farmacología , Calotropis/química , Péptido Hidrolasas/farmacología , Proteínas de Plantas/farmacología , Infecciones por Salmonella/tratamiento farmacológico , Salmonella typhimurium/efectos de los fármacos , Animales , Antiinflamatorios/aislamiento & purificación , Regulación de la Expresión Génica , Interleucina-10/genética , Interleucina-10/inmunología , Interleucina-1beta/genética , Interleucina-1beta/inmunología , Interleucina-6/genética , Interleucina-6/inmunología , Látex/química , Lipopolisacáridos/antagonistas & inhibidores , Lipopolisacáridos/farmacología , Macrófagos Peritoneales/efectos de los fármacos , Macrófagos Peritoneales/inmunología , Ratones , Péptido Hidrolasas/aislamiento & purificación , Componentes Aéreos de las Plantas/química , Extractos Vegetales/química , Proteínas de Plantas/aislamiento & purificación , Plantas Medicinales , Cultivo Primario de Células , Infecciones por Salmonella/inmunología , Infecciones por Salmonella/microbiología , Infecciones por Salmonella/patología , Salmonella typhimurium/inmunología , Salmonella typhimurium/patogenicidad , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/inmunología

RESUMEN

Type 1 diabetes mellitus (T1D) is a chronic autoimmune disease characterized by insulin-producing pancreatic ß-cell destruction and hyperglycemia. While monocytes and NOD-like receptor family-pyrin domain containing 3 (NLRP3) are associated with T1D onset and development, the specific receptors and factors involved in NLRP3 inflammasome activation remain unknown. Herein, we evaluated the inflammatory state of resident peritoneal macrophages (PMs) from genetically modified non-obese diabetic (NOD), NLRP3-KO, wild-type (WT) mice and in peripheral blood mononuclear cells (PBMCs) from human T1D patients. We also assessed the effect of docosahexaenoic acid (DHA) on the inflammatory status. Macrophages from STZ-induced T1D mice exhibited increased inflammatory cytokine/chemokine levels, nitric oxide (NO) secretion, NLRP3 and iNOS protein levels, and augmented glycolytic activity compared to control animals. In PMs from NOD and STZ-induced T1D mice, DHA reduced NO production and attenuated the inflammatory state. Furthermore, iNOS and IL-1ß protein expression levels and NO production were lower in the PMs from diabetic NLRP3-KO mice than from WT mice. We also observed increased IL-1ß secretion in PBMCs from T1D patients and immortalized murine macrophages treated with advanced glycation end products and palmitic acid. The present study demonstrated that the resident PMs are in a proinflammatory state characterized by increased NLRP3/iNOS pathway-mediated NO production, up-regulated proinflammatory cytokine/chemokine receptor expression and altered glycolytic activity. Notably, ex vivo treatment with DHA reverted the diabetes-induced changes and attenuated the macrophage inflammatory state. It is plausible that DHA supplementation could be employed as adjuvant therapy for treating individuals with T1D.

Asunto(s)

Antiinflamatorios/farmacología , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Ácidos Docosahexaenoicos/farmacología , Inflamación/tratamiento farmacológico , Activación de Macrófagos/efectos de los fármacos , Macrófagos Peritoneales/efectos de los fármacos , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismo , Adulto , Animales , Células Cultivadas , Citocinas/metabolismo , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/enzimología , Diabetes Mellitus Experimental/inmunología , Diabetes Mellitus Tipo 1/inducido químicamente , Diabetes Mellitus Tipo 1/enzimología , Diabetes Mellitus Tipo 1/inmunología , Femenino , Humanos , Inflamación/inducido químicamente , Inflamación/enzimología , Inflamación/inmunología , Mediadores de Inflamación/metabolismo , Macrófagos Peritoneales/enzimología , Macrófagos Peritoneales/inmunología , Masculino , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Ratones Noqueados , Persona de Mediana Edad , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Embarazo , Transducción de Señal , Estreptozocina

RESUMEN

Melanin is a Sporothrix virulence factor that can inhibit the innate immune functions of macrophages such as phagocytosis and killing. However, no data on melanin's influence on antigen presentation by macrophages are available. In this study, we used conidia, yeasts, and melanin ghosts (MGs) from a black Sporothrix globosa strain (MEL+) and its ultraviolet-induced albino mutant (MEL-), to study the influence of melanin on expression of molecules involved in antigen presentation by mouse macrophages (MHC class II, CD80, CD86), as well as on levels of transcription factors regulating their expression (CIITA and promoters I, III, and IV). A murine infection model was used to assess the virulence of both strains and differences in expression of MHC class II and CD80/86 in vivo. MHC class II, CD86 CIITA, and PIV expressions were lower in macrophages infected with MEL+ than in macrophages infected with MEL- conidia, while CD80 expression was similar. No statistical difference in gene expression was observed between macrophages infected by MEL+ and MEL- yeasts. Infection by MGs alone had no clear effect on expression of antigen presentation-associated molecules. Mice infected with MEL+ S. globosa had significantly higher fungal burdens in the lung, liver, spleen, kidney, and testicle compared with mice infected with MEL- S. globosa 21 days post-infection. MHC class II expression changes in the animal study were similar to those observed in the in vitro experiment. Our results indicate that S. globosa melanin can inhibit expression of antigen presentation-associated molecules during both the early and late stages of infection, representing a new mechanism to evade host immunity and to enhance dissemination. Further investigations of melanin's impact on adaptive immunity will be helpful in understanding this fungal virulence factor.

Asunto(s)

Macrófagos Peritoneales/inmunología , Melaninas/inmunología , Sporothrix/inmunología , Esporotricosis/microbiología , Animales , Presentación de Antígeno , Antígenos de Histocompatibilidad Clase II/genética , Antígenos de Histocompatibilidad Clase II/inmunología , Interacciones Huésped-Patógeno , Humanos , Hígado/microbiología , Pulmón/microbiología , Macrófagos Peritoneales/microbiología , Masculino , Ratones , Ratones Endogámicos BALB C , Sporothrix/genética , Esporotricosis/genética , Esporotricosis/inmunología

RESUMEN

Morita-Baylis-Hillman adducts (MBHA) are synthetic molecules with several biological actions already described in the literature. It has been previously described that adduct 2-(3-hydroxy-2-oxoindolin-3-yl)acrylonitrile (ISACN) has anticancer potential in leukemic cells. Inflammation is often associated with the development and progression of cancer. Therefore, to better understand the effect of ISACN, this study aimed to evaluate the anti-inflammatory potential of ISACN both in vitro and in vivo. Results demonstrated that ISACN negatively modulated the production of inflammatory cytokines IL-1ß, TNF-α, and IL-6 by cultured macrophages. In vivo, ISACN 6 and 24 mg/kg treatment promoted reduced leukocyte migration, especially neutrophils, to the peritoneal cavity of zymosan-challenged animals. ISACN displays no anti-edematogenic activity, but it was able to promote a significant reduction in the production of inflammatory cytokines in the peritoneal cavity. These data show, for the first time, that MBHA ISACN negatively modulates several aspects of the inflammatory response, such as cell migration and cytokine production in vivo and in vitro, thus having an anti-inflammatory potential.

Asunto(s)

Acrilonitrilo/farmacología , Antiinflamatorios/farmacología , Citocinas/metabolismo , Mediadores de Inflamación/metabolismo , Macrófagos Peritoneales/efectos de los fármacos , Peritonitis/prevención & control , Acrilonitrilo/análogos & derivados , Animales , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/metabolismo , Ratones , Infiltración Neutrófila/efectos de los fármacos , Neutrófilos/efectos de los fármacos , Neutrófilos/inmunología , Neutrófilos/metabolismo , Peritonitis/inducido químicamente , Peritonitis/inmunología , Peritonitis/metabolismo , Zimosan

RESUMEN

BACKGROUND: Low molecular weight carrageenan (Cg) is a seaweed-derived sulfated polysaccharide widely used as inflammatory stimulus in preclinical studies. However, the molecular mechanisms of Cg-induced inflammation are not fully elucidated. The present study aimed to investigate the molecular basis involved in Cg-induced macrophages activation and cytokines production. METHODS: Primary culture of mouse peritoneal macrophages were stimulated with Kappa Cg. The supernatant and cell lysate were used for ELISA, western blotting, immunofluorescence. Cg-induced mouse colitis was also developed. RESULTS: Here we show that Cg activates peritoneal macrophages to produce pro-inflammatory cytokines such as TNF and IL-1ß. While Cg-induced TNF production/secretion depends on TLR4/MyD88 signaling, the production of pro-IL-1ß relies on TLR4/TRIF/SYK/reactive oxygen species (ROS) signaling pathway. The maturation of pro-IL1ß into IL-1ß is dependent on canonical NLRP3 inflammasome activation via Pannexin-1/P2X7/K+ efflux signaling. In vivo, Cg-induced colitis was reduced in mice in the absence of NLRP3 inflammasome components. CONCLUSIONS: In conclusion, we unravel a critical role of the NLRP3 inflammasome in Cg-induced pro-inflammatory cytokines production and colitis, which is an important discovery on the pro-inflammatory properties of this sulfated polysaccharide for pre-clinical studies. Video abstract Carrageenan (Cg) is one the most used flogistic stimulus in preclinical studies. Nevertheless, the molecular basis of Cg-induced inflammation is not totally elucidated. Herein, Lopes et al. unraveled the molecular basis for Cg-induced macrophages production of biological active IL-1ß. The Cg-stimulated macrophages produces pro-IL-1ß depends on TLR4/TRIF/Syk/ROS, whereas its processing into mature IL-1ß is dependent on the canonical NLRP3 inflammasome.

Asunto(s)

Carragenina/inmunología , Citocinas/inmunología , Activación de Macrófagos , Macrófagos Peritoneales/inmunología , Animales , Células Cultivadas , Inflamasomas/inmunología , Inflamación/inmunología , Interleucina-1beta/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Proteína con Dominio Pirina 3 de la Familia NLR/inmunología , Factor de Necrosis Tumoral alfa/inmunología

RESUMEN

B-1 cells are a B-lymphocyte subtype whose roles in immunity are not completely defined. These cells can produce cytokines (mainly IL-10) and natural and specific antibodies. Currently, extracellular vesicles (EVs) released by immune cells have emerged as new important entities in cell-cell communication. Immune cells release EVs that can activate and/or modulate other immune cells. Here, we characterized the EVs released by peritoneal B-1 cells infected or not with Leishmania (Leishmania) amazonensis. This Leishmania species causes cutaneous leishmaniasis and can infect macrophages and B-1 cells. Our results showed that peritoneal B-1 cells spontaneously release EVs, but the parasite stimulated an increase in EVs production by peritoneal B-1 cells. The treatment of BALB/c and C57BL/6 bone marrow-derived macrophages (BMDM) with EVs from infected peritoneal B-1 cells led to differential expression of iNOS, IL-6, IL-10, and TNF-α. Additionally, BALB/c mice previous treated with EVs released by peritoneal B-1 cells showed a significant lower lesion size and parasite burden. Thus, this study demonstrated that peritoneal B-1 cells could release EVs that can alter the functions of macrophages in vitro and in vivo these EVs altered the course of L. amazonensis infection. These findings represent the first evidence that EVs from peritoneal B-1 cells can act as a new mechanism of cellular communication between macrophages and B-1 cells, contributing to immunity against experimental leishmaniasis.

Asunto(s)

Subgrupos de Linfocitos B/inmunología , Comunicación Celular/inmunología , Vesículas Extracelulares/inmunología , Leishmania/inmunología , Leishmaniasis/inmunología , Macrófagos Peritoneales/inmunología , Animales , Subgrupos de Linfocitos B/patología , Citocinas/inmunología , Vesículas Extracelulares/patología , Femenino , Leishmaniasis/patología , Macrófagos Peritoneales/patología , Ratones , Ratones Endogámicos BALB C , Óxido Nítrico Sintasa de Tipo II/inmunología

RESUMEN

Annexin A1 (AnxA1) is a potent anti-inflammatory protein that downregulates proinflammatory cytokine release. This study evaluated the role of AnxA1 in the regulation of NLRP3 inflammasome activation and lipid release by starch-elicited murine peritoneal macrophages. C57bl/6 wild-type (WT) and AnxA1-null (AnxA1-/-) mice received an intraperitoneal injection of 1.5% starch solution for macrophage recruitment. NLRP3 was activated by priming cells with lipopolysaccharide for 3 h, followed by nigericin (1 h) or ATP (30 min) incubation. As expected, nigericin and ATP administration decreased elicited peritoneal macrophage viability and induced IL-1ß release, more pronounced in the AnxA1-/- cells than in the control peritoneal macrophages. In addition, nigericin-activated AnxA1-/- macrophages showed increased levels of NLRP3, while points of co-localization of the AnxA1 protein and NLRP3 inflammasome were detected in WT cells, as demonstrated by ultrastructural analysis. The lipidomic analysis showed a pronounced release of prostaglandins in nigericin-stimulated WT peritoneal macrophages, while ceramides were detected in AnxA1-/- cell supernatants. Different eicosanoid profiles were detected for both genotypes, and our results suggest that endogenous AnxA1 regulates the NLRP3-derived IL-1ß and lipid mediator release in macrophages.

Asunto(s)

Anexina A1/metabolismo , Inflamasomas/metabolismo , Macrófagos Peritoneales/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Animales , Anexina A1/inmunología , Inflamasomas/inmunología , Metabolismo de los Lípidos , Macrófagos Peritoneales/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL

RESUMEN

Bursera morelensis is used in Mexican folk medicine to treat wounds on the skin. It is an endemic tree known as "aceitillo", and the antibacterial and antifungal activity of its essential oil has been verified; it also acts as an anti-inflammatory. All of these reported biological activities make the essential oil of B. morelensis a candidate to accelerate the wound-healing process. The objective was to determine the wound-healing properties of B. morelensis' essential oil on a murine model. The essential oil was obtained by hydro-distillation, and the chemical analysis was performed by gas chromatography-mass spectrometry (GC-MS). In the murine model, wound-healing efficacy (WHE) and wound contraction (WC) were evaluated. Cytotoxic activity was evaluated in vitro using peritoneal macrophages from BALB/c mice. The results showed that 18 terpenoid-type compounds were identified in the essential oil. The essential oil had remarkable WHE regardless of the dose and accelerated WC and was not cytotoxic. In vitro tests with fibroblasts showed that cell viability was dose-dependent; by adding 1 mg/mL of essential oil (EO) to the culture medium, cell viability decreased below 80%, while, at doses of 0.1 and 0.01 mg/mL, it remained around 90%; thus, EO did not intervene in fibroblast proliferation, but it did influence fibroblast migration when wound-like was done in monolayer cultures. The results of this study demonstrated that the essential oil was a pro-wound-healing agent because it had good healing effectiveness with scars with good tensile strength and accelerated repair. The probable mechanism of action of the EO of B. morelensis, during the healing process, is the promotion of the migration of fibroblasts to the site of the wound, making them active in the production of collagen and promoting the remodeling of this collagen.

Asunto(s)

Bursera/química , Aceites Volátiles/farmacología , Aceites de Plantas/farmacología , Cicatrización de Heridas/efectos de los fármacos , Animales , Cromatografía de Gases y Espectrometría de Masas , Macrófagos Peritoneales/efectos de los fármacos , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/metabolismo , Ratones , Ratones Endogámicos BALB C , Aceites Volátiles/química , Fitoquímicos/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Aceites de Plantas/química , Piel/efectos de los fármacos , Piel/metabolismo , Piel/patología

RESUMEN

CCL3, a member of the CC-chemokine family, has been associated with macrophage recruitment to heart tissue and parasite control in the acute infection of mouse with Trypanosoma cruzi, the causative agent of Chagas disease. Here, we approached the participation of CCL3 in chronic chagasic cardiomyopathy (CCC), the main clinical form of Chagas disease. We induced CCC in C57BL/6 (ccl3+/+) and CCL3-deficient (ccl3-/-) mice by infection with the Colombian Type I strain. In ccl3+/+ mice, high levels of CCL3 mRNA and protein were detected in the heart tissue during the acute and chronic infection. Survival was not affected by CCL3 deficiency. In comparison with ccl3+/+, chronically infected ccl3-/- mice presented reduced cardiac parasitism and inflammation due to CD8+ cells and macrophages. Leukocytosis was decreased in infected ccl3-/- mice, paralleling the accumulation of CD8+ T cells devoid of activated CCR5+ LFA-1+ cells in the spleen. Further, T. cruzi-infected ccl3-/-mice presented reduced frequency of interferon-gamma (IFNγ)+ cells and numbers of parasite-specific IFNγ-producing cells, while the T. cruzi antigen-specific cytotoxic activity was increased. Stimulation of CCL3-deficient macrophages with IFNγ improved parasite control, in a milieu with reduced nitric oxide (NOx) and tumor necrosis factor (TNF), but similar interleukin-10 (IL-10), concentrations. In comparison with chronically T. cruzi-infected ccl3+/+ counterparts, ccl3-/- mice did not show enlarged heart, loss of left ventricular ejection fraction, QTc prolongation and elevated CK-MB activity. Compared with ccl3+/+, infected ccl3-/- mice showed reduced concentrations of TNF, while IL-10 levels were not affected, in the heart milieu. In spleen of ccl3+/+ NI controls, most of the CD8+ T-cells expressing the CCL3 receptors CCR1 or CCR5 were IL-10+, while in infected mice these cells were mainly TNF+. Lastly, selective blockage of CCR1/CCR5 (Met-RANTES therapy) in chronically infected ccl3+/+ mice reversed pivotal electrical abnormalities (bradycardia, prolonged PR, and QTc interval), in correlation with reduced TNF and, mainly, CCL3 levels in the heart tissue. Therefore, in the chronic T. cruzi infection CCL3 takes part in parasite persistence and contributes to form a CD8+ T-cell and macrophage-enriched cardiac inflammation. Further, increased levels of CCL3 create a scenario with abundant IFNγ and TNF, associated with cardiomyocyte injury, heart dysfunction and QTc prolongation, biomarkers of severity of Chagas' heart disease.

Asunto(s)

Cardiomiopatía Chagásica/fisiopatología , Quimiocina CCL3/fisiología , Interferón gamma/fisiología , Macrófagos Peritoneales/parasitología , Parasitemia/fisiopatología , Trypanosoma cruzi/fisiología , Factor de Necrosis Tumoral alfa/fisiología , Animales , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/inmunología , Células Cultivadas , Cardiomiopatía Chagásica/parasitología , Cardiomiopatía Chagásica/patología , Quimiocina CCL3/deficiencia , Quimiocina CCL3/farmacología , Quimiocina CCL5/farmacología , Quimiocina CCL5/uso terapéutico , Quimiotaxis de Leucocito/efectos de los fármacos , Citocinas/biosíntesis , Citocinas/genética , Citocinas/farmacología , Electrocardiografía/efectos de los fármacos , Femenino , Interferón gamma/farmacología , Macrófagos Peritoneales/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Miocarditis/etiología , Miocarditis/patología , Miocarditis/fisiopatología , ARN Mensajero/biosíntesis , Receptores de Quimiocina/antagonistas & inhibidores , Receptores de Quimiocina/biosíntesis , Receptores de Quimiocina/genética , Organismos Libres de Patógenos Específicos , Bazo/inmunología , Bazo/metabolismo , Volumen Sistólico , Trypanosoma cruzi/aislamiento & purificación , Factor de Necrosis Tumoral alfa/análisis

RESUMEN

Moderate aerobic training may be therapeutic for chronic low-grade inflammatory diseases due to the associated anti-inflammatory response that is mediated by immune cells. The peroxisome proliferator-activated receptor gamma (PPARγ) regulates the M1 (pro-inflammatory) and M2 (anti-inflammatory) polarization, as well as the immunometabolic response of macrophages. Against this background, the present study seeks to clarify whether the conditional deletion of PPARγ in macrophages would have any effect on the anti-inflammatory role of moderate aerobic training. To test this hypothesis, two mice strains were used: PPARγ LyzCre+/+ (KO) and littermates control animals (WT). Each genotype was divided into 1) sedentary high-fat diet (HF) and 2) high-fat diet and moderate aerobic training (HFT) (n = 5-8 per group). The experimental protocol lasted for 12 weeks, comprising 4 weeks of HF diet only and 8 weeks of HF diet and aerobic training (5 times/week, 50-60 minutes/day at 60% of maximum speed). Metabolic analyses were carried out on the serum glucose homeostase, adipose tissue morphology and cytokine content, and macrophage cytokine production.Immunophenotyping and gene expression were also performed. KO male mice were more prone to hypertrophy in the subcutaneous adipose tissue, though only the IL-1ß (p = 0.0049) was higher compared to the values observed in WT animals. Peritoneal macrophages from KO animals exhibited a marked inflammatory environment with an increase in TNF-α (p = 0.0008), IL- 1ß (p = 0.0017), and IL-6 (p < 0.0001) after lipopolysaccharide stimulation. The moderate aerobic training protected both genotypes from weight gain and reduced the caloric intake in the KO animals. Despite the attenuation of the M2 marker CD206 (p < 0.001) in the absence of PPAR-γ, the aerobic training modulated cytokine production in LPS stimulated peritoneal macrophages from both genotypes, reducing proinflammatory cytokines such as TNF-α (p = 0.0002) and IL-6 (p < 0.0001). Overall, our findings demonstrate the essential role of PPARγ in macrophage immunophenotypes. However, the deletion of PPARγ did not inhibit the exercise-mediated anti-inflammatory effect, underscoring the important role of exercise in modulating inflammation.

Asunto(s)

Inflamación/inmunología , Macrófagos Peritoneales/inmunología , PPAR gamma/inmunología , Condicionamiento Físico Animal , Animales , Dieta Alta en Grasa , Inmunofenotipificación , Interleucina-1beta/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Obesos , Factor de Necrosis Tumoral alfa/inmunología

RESUMEN

Sepsis is a leading cause of morbidity and mortality in intensive care units. Previously, we identified Protein Kinase C-delta (PKCδ) as an important regulator of the inflammatory response in sepsis. An important issue in development of anti-inflammatory therapeutics is the risk of immunosuppression and inability to effectively clear pathogens. In this study, we investigated whether PKCδ inhibition prevented organ dysfunction and improved survival without compromising pathogen clearance. Sprague Dawley rats underwent sham surgery or cecal ligation and puncture (CLP) to induce sepsis. Post-surgery, PBS or a PKCδ inhibitor (200µg/kg) was administered intra-tracheally (IT). At 24 hours post-CLP, there was evidence of lung and kidney dysfunction. PKCδ inhibition decreased leukocyte influx in these organs, decreased endothelial permeability, improved gas exchange, and reduced blood urea nitrogen/creatinine ratios indicating organ protection. PKCδ inhibition significantly decreased bacterial levels in the peritoneal cavity, spleen and blood but did not exhibit direct bactericidal properties. Peritoneal chemokine levels, neutrophil numbers, or macrophage phenotypes were not altered by PKCδ inhibition. Peritoneal macrophages isolated from PKCδ inhibitor-treated septic rats demonstrated increased bacterial phagocytosis. Importantly, PKCδ inhibition increased survival. Thus, PKCδ inhibition improved survival and improved survival was associated with increased phagocytic activity, enhanced pathogen clearance, and decreased organ injury.

Asunto(s)

Bacterias/inmunología , Inhibidores Enzimáticos/farmacología , Macrófagos Peritoneales , Neutrófilos , Proteína Quinasa C-delta/antagonistas & inhibidores , Sepsis , Animales , Quimiocinas , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/patología , Masculino , Neutrófilos/inmunología , Neutrófilos/patología , Fagocitosis/efectos de los fármacos , Proteína Quinasa C-delta/inmunología , Ratas , Ratas Sprague-Dawley , Sepsis/tratamiento farmacológico , Sepsis/inmunología , Sepsis/microbiología , Sepsis/patología

RESUMEN

The severity of Plasmodium falciparum malaria is associated with parasite cytoadherence, but there is limited knowledge about the effect of parasite cytoadherence in malaria-associated acute respiratory distress syndrome (ARDS). Our objective was to evaluate the cytoadherence of infected red blood cells (iRBCs) in a murine model of ARDS and to appraise a potential function of endothelial protein C receptor (EPCR) in ARDS pathogenesis. DBA/2 mice infected with P. berghei ANKA were classified as ARDS- or hyperparasitemia- (HP-) developing mice according to respiratory parameters and parasitemia. Lungs, blood, and bronchoalveolar lavage were collected for gene expression or protein analyses. Primary cultures of microvascular lung endothelial cells from DBA/2 mice were analyzed for iRBC interactions. Lungs from ARDS-developing mice showed evidence of iRBC accumulation along with an increase in EPCR and TNF concentrations. Furthermore, TNF increased iRBC adherence in vitro. Dexamethasone-treated infected mice showed low levels of TNF and EPCR mRNA expression and, finally, decreased vascular permeability, thus protecting mice from ARDS. In conclusion, we identified that increased iRBC cytoadherence in the lungs underlies malaria-associated ARDS in DBA/2-infected mice and that inflammation increased cytoadherence capacity, suggesting a participation of EPCR and a conceivable target for drug development.

Asunto(s)

Susceptibilidad a Enfermedades , Receptor de Proteína C Endotelial/metabolismo , Malaria/complicaciones , Malaria/parasitología , Síndrome de Dificultad Respiratoria/etiología , Síndrome de Dificultad Respiratoria/metabolismo , Animales , Biomarcadores , Citocinas/metabolismo , Modelos Animales de Enfermedad , Expresión Génica , Inmunohistoquímica , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/metabolismo , Masculino , Ratones , Plasmodium berghei , Plasmodium falciparum , Síndrome de Dificultad Respiratoria/tratamiento farmacológico , Síndrome de Dificultad Respiratoria/patología

RESUMEN

Galectin-3 (Gal-3) controls intercellular and cell-extracellular matrix interactions during immunological responses. In chronic inflammation, Gal-3 is associated with fibrotic events, regulates B cell differentiation and delays lupus progression. Gal-3 deficient mice (Lgals3-/-) have intense germinal center formation and atypical plasma cell generation correlated to high levels IgG, IgE, and IgA. Here, we used pristane (2,6,10,14-tetramethylpentadecane) to induce lupus-like syndrome in Lgals3-/- and Lgals3+/+ BALB/c mice. Mesentery and peritoneal cells were monitored because promptly react to pristane injected in the peritoneal cavity. For the first time, mesenteric tissues have been associated to the pathogenesis of experimental lupus-like syndrome. In Lgals3+/+ pristane-induced mice, mesentery was hallmarked by intense fibrogranulomatous reaction restricted to submesothelial regions and organized niches containing macrophages and B lymphocytes and plasma cells. In contrast, Lgals3-/- pristane-treated mice had diffuse mesenteric fibrosis affecting submesothelium and peripheral tissues, atypical M1/M2 macrophage polarization and significant DLL1+ cells expansion, suggesting possible involvement of Notch/Delta pathways in the disease. Early inflammatory reaction to pristane was characterized by significant disturbances on monocyte recruitment, macrophage differentiation and dendritic cell (DC) responses in the peritoneal cavity of pristane-induced Lgals3-/- mice. A correlative analysis showed that mesenteric damages in the absence of Gal-3 were directly associated with severe portal inflammation and hepatitis. In conclusion, it has suggested that Gal-3 orchestrates histological organization in the mesentery and prevents lupoid hepatitis in experimental lupus-like syndrome by controlling macrophage polarization, Notch signaling pathways and DC differentiation in mesenteric structures.

Asunto(s)

Galectina 3/metabolismo , Hepatitis/inmunología , Lupus Eritematoso Sistémico/inmunología , Macrófagos Peritoneales/inmunología , Mesenterio/patología , Animales , Modelos Animales de Enfermedad , Femenino , Fibrosis , Galectina 3/genética , Hepatitis/patología , Humanos , Inyecciones Intraperitoneales , Hígado/inmunología , Hígado/patología , Lupus Eritematoso Sistémico/inducido químicamente , Lupus Eritematoso Sistémico/complicaciones , Mesenterio/citología , Mesenterio/inmunología , Ratones , Ratones Noqueados , Terpenos/administración & dosificación , Terpenos/inmunología

RESUMEN

Here, we have investigated the possible effect of B-1 cells on the activity of peritoneal macrophages in E. cuniculi infection. In the presence of B-1 cells, peritoneal macrophages had an M1 profile with showed increased phagocytic capacity and index, associated with the intense microbicidal activity and a higher percentage of apoptotic death. The absence of B-1 cells was associated with a predominance of the M2 macrophages, reduced phagocytic capacity and index and microbicidal activity, increased pro-inflammatory and anti-inflammatory cytokines production, and higher percentual of necrosis death. In addition, in the M2 macrophages, spore of phagocytic E. cuniculi with polar tubular extrusion was observed, which is an important mechanism of evasion of the immune response. The results showed the importance of B-1 cells in the modulation of macrophage function against E. cuniculi infection, increasing microbicidal activity, and reducing the fungal mechanisms involved in the evasion of the immune response.

Asunto(s)

Subgrupos de Linfocitos B , Encephalitozoon cuniculi/inmunología , Encefalitozoonosis/inmunología , Encefalitozoonosis/patología , Macrófagos Peritoneales/inmunología , Animales , Apoptosis , Células Cultivadas , Femenino , Macrófagos Peritoneales/microbiología , Ratones Endogámicos BALB C , Fagocitosis/inmunología , Esporas Fúngicas/crecimiento & desarrollo , Esporas Fúngicas/inmunología , Enfermedades por Inmunodeficiencia Combinada Ligada al Cromosoma X/genética