RESUMO
Hybrid diamond-like carbon (DLC) with incorporated titanium dioxide (TiO2) nanoparticle coatings have low friction coefficient, high wear resistance, high hardness, biocompatibility, and high chemical stability. They could be employed to modify biomedical alloys surfaces for numerous applications in biomedical engineering. Here we investigate for the first time the in vivo inflammatory process of DLC coatings with incorporated TiO2 nanoparticles. TiO2-DLC films were grown on AISI 316 stainless-steel substrates using plasma-enhanced chemical vapor deposition. The coated substrates were implanted in CF1 mice peritoneum. The in vivo cytotoxicity and biocompatibility of the samples were analyzed from macrophage lavage. Analysis in the first weeks after implantation could be helpful to evaluate the acute cytotoxicity generated after a possible inflammatory process. The in vivo results showed no inflammatory process. A significant increase in nitric oxide production on the uncoated substrates was confirmed through cytometry, and the coated substrates demonstrated biocompatibility. The presence of TiO2 nanoparticles enhanced the wound healing activity, due to their astringent and antimicrobial properties. DLC and TiO2-DLC coatings were considered biocompatible, and the presence of TiO2 nanoparticles reduced the inflammatory reactions, increasing DLC biocompatibility.
Assuntos
Carbono/química , Membranas Artificiais , Nanopartículas Metálicas/química , Próteses e Implantes , Titânio/química , Ligas , Animais , Carbono/farmacologia , Materiais Revestidos Biocompatíveis/síntese química , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Diamante/química , Dureza , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/fisiologia , Teste de Materiais , Nanopartículas Metálicas/uso terapêutico , Camundongos , Aço Inoxidável/química , Aço Inoxidável/farmacologia , Propriedades de Superfície , Titânio/farmacologiaRESUMO
Sepsis caused by Gram-negative bacteria is the consequence of an unrestrained infection that continuously releases lipopolysaccharide (LPS) into the bloodstream, which triggers an uncontrolled systemic inflammatory response leading to multiorgan failure and death. After scrutinizing the immune modulation exerted by a recombinant Fasciola hepatica fatty acid binding protein termed Fh15, our group demonstrated that addition of Fh15 to murine macrophages 1 h prior to LPS stimulation significantly suppresses the expression of proinflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin-1ß (IL1-ß). The present study aimed to demonstrate that Fh15 could exert a similar anti-inflammatory effect in vivo using a mouse model of septic shock. Among the novel findings reported in this article, (i) Fh15 suppressed numerous serum proinflammatory cytokines/chemokines when injected intraperitoneally 1 h after exposure of animals to lethal doses of LPS, (ii) concurrently, Fh15 increased the population of large peritoneal macrophages (LPMs) in the peritoneal cavity (PerC) of LPS-injected animals, and (iii) Fh15 downregulated the expression on spleen macrophages of CD38, a cell surface ectoenzyme with a critical role during inflammation. These findings present the first evidence that the recombinant parasitic antigen Fh15 is an excellent modulator of the PerC cell content and in vivo macrophage activation, endorsing Fh15's potential as a drug candidate against sepsis-related inflammatory response.IMPORTANCE Sepsis is a potentially life-threatening complication of an infection. Sepsis is mostly the consequence of systemic bacterial infections leading to exacerbated activation of immune cells by bacterial products, resulting in enhanced release of inflammatory mediators. Lipopolysaccharide (LPS), the major component of the outer membrane of Gram-negative bacteria, is a critical factor in the pathogenesis of sepsis, which is sensed by Toll-like receptor 4 (TLR4). The scientific community highly pursues the development of antagonists capable of blocking the cytokine storm by blocking TLR4. We report here that a recombinant molecule of 14.5 kDa belonging to the Fasciola hepatica fatty acid binding protein (Fh15) is capable of significantly suppressing the LPS-induced cytokine storm in a mouse model of septic shock when administered by the intraperitoneal route 1 h after a lethal LPS injection. These results suggest that Fh15 is an excellent candidate for drug development against endotoxemia.
Assuntos
Movimento Celular/efeitos dos fármacos , Citocinas/metabolismo , Proteínas de Ligação a Ácido Graxo/administração & dosagem , Proteínas de Helminto/administração & dosagem , Lipopolissacarídeos/imunologia , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/fisiologia , Choque Séptico/patologia , ADP-Ribosil Ciclase 1/análise , Animais , Células Cultivadas , Citosol/química , Modelos Animais de Doenças , Ácidos Graxos/análise , Injeções Intravenosas , Glicoproteínas de Membrana/análise , Camundongos , Proteínas Recombinantes/administração & dosagem , Baço/imunologiaRESUMO
Previously, we reported that Lactobacillus rhamnosus CRL1505 peptidoglycan (PG05) improves the innate immune response in immunocompromised-malnourished mice after Streptococcus pneumoniae infection. This study extends those previous findings by demonstrating that the dietary recovery of malnourished mice with nasal administration of PG05 improves not only the innate immune response but the respiratory and systemic adaptive humoral response as well. PG05 enhanced the Th2 response, the recovery of B cells, and the concentration and opsonophagocytic activity of anti-pneumococcal antibodies. In addition, by performing comparative studies with the peptidoglycans from lactobacilli of the same species (L. rhamnosus CRL534) or with similar immunomodulatory properties (L. plantarum CRL1506), we demonstrated here that PG05 has unique immunomodulatory properties that cannot be extended to peptidoglycans from other probiotic strains. However, the knowledge of the molecular characteristics of PG05 is indispensable to understand immunomodulatory abilities of L. rhamnosus CRL1505.
Assuntos
Fatores Imunológicos/uso terapêutico , Imunoterapia/métodos , Lacticaseibacillus rhamnosus/imunologia , Desnutrição/complicações , Peptidoglicano/uso terapêutico , Pneumonia Pneumocócica/terapia , Probióticos , Imunidade Adaptativa , Administração Intranasal , Animais , Anticorpos Antibacterianos/sangue , Bacteriemia/imunologia , Bacteriemia/microbiologia , Líquido da Lavagem Broncoalveolar/citologia , Citocinas/sangue , Imunidade Celular , Hospedeiro Imunocomprometido , Fatores Imunológicos/administração & dosagem , Lactobacillus plantarum/imunologia , Contagem de Leucócitos , Pulmão/patologia , Macrófagos Peritoneais/fisiologia , Masculino , Desnutrição/dietoterapia , Desnutrição/imunologia , Camundongos , Peptidoglicano/administração & dosagem , Peptidoglicano/imunologia , Peptidoglicano/farmacologia , Fagocitose , Pneumonia Pneumocócica/imunologia , Pneumonia Pneumocócica/patologia , Streptococcus pneumoniae/imunologiaRESUMO
Macrophages have been considered an elusive yet emerging therapeutic target in tumor development since they are an important component in tumor microenvironment. The purpose of the present study was to evaluate the effect of C. sinensis on macrophage function (a component of tumor microenvironment which can alter the virulence of cancer) in high-fat diet fed rats. IMR-32 human neuroblastoma cell cytotoxicity was also investigated. The following parameters were observed to evaluate macrophage function: superoxide anion, hydrogen peroxide, nitric oxide, lysosomal volume and phagocytic capacity. High fat diet (HFD) plus C. sinensis supplementation promoted a decreased superoxide anion and hydrogen peroxide levels as well as lysosomal volume and phagocytic capacity. Nitric oxide was increased in the same group. In summary, C. sinensis offered an important anti-tumoral perspective from the standpoint of the tumor microenvironment and in vitro IMR-32 cytotoxicity.
Assuntos
Antineoplásicos/farmacologia , Cordyceps , Dieta Hiperlipídica , Hiperlipidemias/fisiopatologia , Macrófagos Peritoneais/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Animais , Antineoplásicos/isolamento & purificação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cordyceps/química , Humanos , Peróxido de Hidrogênio/metabolismo , Hiperlipidemias/etiologia , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos Peritoneais/fisiologia , Masculino , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Óxido Nítrico/metabolismo , Ratos Wistar , Superóxidos/metabolismo , Microambiente Tumoral/efeitos dos fármacosRESUMO
Stressors can increase plasma glucocorticoid (GC) levels and decrease plasma androgen levels in different species of vertebrates. GCs can have immune-enhancing or immunosuppressive effects, which are dependent upon stress duration and intensity. The worldwide decline in amphibian populations is strongly linked to an array of different stressors. The impacts of stress on GCs, androgens, and the immune response are important to clarify and should lead to the better development of conservation strategies. The present study in adult male toads of Rhinella schneideri investigated the effects of captivity (7, 30, and 60 days) on plasma corticosterone (CORT) and plasma testosterone (T), as well as innate immune responses, specifically humoral and cell mediated responses, as indicated by bacterial killing ability (BKA) and phagocytosis by peritoneal cells, respectively. Captivity increased CORT threefold and decreased T versus controls. CORT maintained a threefold elevation throughout the captivity period, while body mass and T gradually decreased with time in captivity. BKA was lower at day 30, versus days 7 and 60, while peritoneal cell phagocytic efficiency decreased after day 30, remaining low at day 60. Moreover, phagocytosis efficiency was positively associated with T and body condition, suggesting that the effects of chronic stress on reproductive potential and immune response might be associated with the state of energetic reserves.
Assuntos
Bufonidae/sangue , Corticosterona/sangue , Imunidade Celular/fisiologia , Macrófagos Peritoneais/fisiologia , Testosterona/sangue , Animais , Animais de Zoológico , Tamanho Corporal , Bufonidae/imunologia , MasculinoRESUMO
Mansonic schistosomiasis is a disease caused by the trematode Schistosoma mansoni, endemic to tropical countries. S. mansoni infection induces the formation of granulomas and potent polarization of Th2-type immune response. There is great interest in understanding the mechanisms used by this parasite that causes a modulation of the immune system. Recent studies from our group demonstrated that lipids of S. mansoni, including lysophosphatidylcholine (LPC) have immunomodulatory activity. In the present study, our aim was to investigate the role of lipids derived from S. mansoni in the activation and polarization of macrophages and to characterize the mechanisms involved in this process. Peritoneal macrophages obtained from wild type C57BL/6mice or bone marrow derived macrophages were stimulated in vitro with lipids extracted from adult worms of S. mansoni. We demonstrated that total schistosomal-derived lipids as well as purified LPC induced alternatively activated macrophages/M2 profile observed by increased expression of arginase-1, mannose receptor, Chi3l3, TGFß and production of IL-10 and PGE2 24h after stimulation. The involvement of the nuclear receptor PPARγ in macrophage response against LPC was investigated. Through Western blot and immunofluorescence confocal microscopy we demonstrated that schistosomal-derived LPC induces increased expression of PPARγ in macrophages. The LPC-induced increased expression of arginase-1 were significantly inhibited by the PPAR-γ antagonist GW9662. Together, these results demonstrate an immunomodulatory role of schistosomal-derived LPC in activating macrophages to a profile of the type M2 through PPARγ-dependent mechanisms, indicating a novel pathway for macrophage polarization triggered by parasite-derived LPC with potential implications to disease pathogenesis.
Assuntos
Lisofosfatidilcolinas/metabolismo , Macrófagos Peritoneais/metabolismo , Macrófagos Peritoneais/fisiologia , PPAR gama/metabolismo , Schistosoma mansoni/metabolismo , Animais , Arginase/metabolismo , Interleucina-10/metabolismo , Lipídeos/fisiologia , Ativação de Macrófagos/fisiologia , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Lipid bodies [lipid droplets (LBs)] are lipid-rich organelles involved in lipid metabolism, signalling and inflammation. Recent findings suggest a role for LBs in host response to infection; however, the potential functions of this organelle in Toxoplasma gondii infection and how it alters macrophage microbicidal capacity during infection are not well understood. Here, we investigated the role of host LBs in T. gondii infection in mouse peritoneal macrophages in vitro. Macrophages cultured with mouse serum (MS) had higher numbers of LBs than those cultured in foetal bovine serum and can function as a model to study the role of LBs during intracellular pathogen infection. LBs were found in association with the parasitophorous vacuole, suggesting that T. gondii may benefit from this lipid source. Moreover, increased numbers of macrophage LBs correlated with high prostaglandin E2 (PGE2) production and decreased nitric oxide (NO) synthesis. Accordingly, LB-enriched macrophages cultured with MS were less efficient at controlling T. gondii growth. Treatment of macrophages cultured with MS with indomethacin, an inhibitor of PGE2 production, increased the microbicidal capacity against T. gondii. Collectively, these results suggest that culture with MS caused a decrease in microbicidal activity of macrophages against T. gondii by increasing PGE2 while lowering NO production.
Assuntos
Gotículas Lipídicas/parasitologia , Ativação de Macrófagos/fisiologia , Macrófagos Peritoneais/parasitologia , Toxoplasma/fisiologia , Vacúolos/parasitologia , Animais , Bovinos , Interações Hospedeiro-Parasita , Indometacina/farmacologia , Gotículas Lipídicas/fisiologia , Macrófagos Peritoneais/química , Macrófagos Peritoneais/fisiologia , Macrófagos Peritoneais/ultraestrutura , Masculino , Camundongos , Camundongos Endogâmicos C3H , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Óxido Nítrico/biossíntese , Cultura Primária de Células , Prostaglandinas E/antagonistas & inibidores , Prostaglandinas E/biossíntese , Vacúolos/fisiologiaRESUMO
Lipid bodies [lipid droplets (LBs)] are lipid-rich organelles involved in lipid metabolism, signalling and inflammation. Recent findings suggest a role for LBs in host response to infection; however, the potential functions of this organelle in Toxoplasma gondii infection and how it alters macrophage microbicidal capacity during infection are not well understood. Here, we investigated the role of host LBs in T. gondii infection in mouse peritoneal macrophages in vitro. Macrophages cultured with mouse serum (MS) had higher numbers of LBs than those cultured in foetal bovine serum and can function as a model to study the role of LBs during intracellular pathogen infection. LBs were found in association with the parasitophorous vacuole, suggesting that T. gondii may benefit from this lipid source. Moreover, increased numbers of macrophage LBs correlated with high prostaglandin E2 (PGE2) production and decreased nitric oxide (NO) synthesis. Accordingly, LB-enriched macrophages cultured with MS were less efficient at controlling T. gondii growth. Treatment of macrophages cultured with MS with indomethacin, an inhibitor of PGE2 production, increased the microbicidal capacity against T. gondii. Collectively, these results suggest that culture with MS caused a decrease in microbicidal activity of macrophages against T. gondii by increasing PGE2 while lowering NO production.
Assuntos
Animais , Bovinos , Masculino , Camundongos , Gotículas Lipídicas/parasitologia , Ativação de Macrófagos/fisiologia , Macrófagos Peritoneais/parasitologia , Toxoplasma/fisiologia , Vacúolos/parasitologia , Interações Hospedeiro-Parasita , Indometacina/farmacologia , Gotículas Lipídicas/fisiologia , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Macrófagos Peritoneais/química , Macrófagos Peritoneais/fisiologia , Macrófagos Peritoneais/ultraestrutura , Óxido Nítrico/biossíntese , Cultura Primária de Células , Prostaglandinas E/antagonistas & inibidores , Prostaglandinas E/biossíntese , Vacúolos/fisiologiaRESUMO
The P2X7 receptor (P2X7R), an ATP-gated cation channel, is expressed predominantly in leukocytes. Activation of P2X7R has been implicated in the formation of a cytolytic pore (i.e., a large conductance channel) that allows the passage of molecules up to 900 Da in macrophages. At least two hypotheses have been presented to explain the conversion of a nonselective cation channel to a cytolytic pore. One hypothesis suggests that the pore is a separate molecular structure activated by P2X7R, and the second asserts that this is an intrinsic property of P2X7R (pore dilation). Based on connexin knockout and hemichannel antagonist studies, some groups have concluded that connexins and pannexins, the hemichannel-forming proteins in vertebrates, are fundamental components of the large conductance channel associated with P2X7R. Dye uptake and electrophysiology experiments were used to evaluate the efficacy and specificity of some hemichannel antagonists under conditions known to open the large conductance channel associated with P2X7R. Hemichannel antagonists and interference RNA (RNAi) targeting pannexin-1 did not affect P2X7R macroscopic currents [ATP, 1,570±189 pA; ATP+100 µM carbenoxolone (CBX), 1,498±100 pA; ATP+1 mM probenecid (Prob), 1,522±9 pA] or dye uptake in a FACS assay (ATP, 63±5%; ATP+100 µM CBX, 51.51±8.4%; ATP+1 mM Prob, 57.7±4.3%) in mouse macrophages. These findings strongly suggest that the high-permeability pore evident after prolonged P2X7R activation does not occur through connexin or pannexin hemichannels in murine macrophages. Another membrane protein may be involved in P2X7R pore formation.
Assuntos
Conexinas/fisiologia , Macrófagos Peritoneais/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Receptores Purinérgicos P2X7/fisiologia , Trifosfato de Adenosina/farmacologia , Animais , Linhagem Celular , Células Cultivadas , Masculino , Camundongos , Antagonistas do Receptor Purinérgico P2X/farmacologia , Ratos , Ratos WistarRESUMO
B-1 cells constitute a distinct B cell population with unique phenotypic and functional characteristics. They represent the main B cell population found in mouse peritoneal and pleural cavities. The communication between B-1 cells and peritoneal macrophages has been previously studied, and the effect this interaction has on macrophages has been previously described. Using an in vitro co-culture model, herein we demonstrated that peritoneal macrophages were able to increase survival rates and to stimulate proliferation of B-1 cells. IL-6 was also found to be important in B-1 cell survival; recombinant IL-6 increases the percentage of viable B-1 cells in culture. Furthermore, molecules involved in the IL-6 signaling pathway, such as STAT-3 and Bcl-2, were highly expressed in B-1 cells after co-culture with peritoneal macrophages. IL-6-deficient peritoneal macrophages were not able to increase B-1 cell survival, confirming the importance of this cytokine. Altogether, our results indicate a novel mechanism in which peritoneal macrophages are able to regulate the B-1 population via IL-6 secretion.