RESUMO
Neutrophils play an important role in periodontitis by producing nitric oxide (NO) and antimicrobial peptides, molecules with microbicidal activity via oxygen-dependent and -independent mechanisms, respectively. It is unknown whether variation in the production of antimicrobial peptides such as LL-37, human neutrophil peptides (HNP) 1-3, and NO by neutrophils influences the pathogenesis of periodontal diseases. We compared the production of these peptides and NO by lipopolysaccharide (LPS)-stimulated neutrophils isolated from healthy subjects and from patients with periodontitis. Peripheral blood neutrophils were cultured with or without Aggregatibacter actinomycetemcomitans-LPS (Aa-LPS), Porphyromonas gingivalis-LPS (Pg-LPS) and Escherichia coli-LPS (Ec-LPS). qRT-PCR was used to determine quantities of HNP 1-3 and LL-37 mRNA in neutrophils. Amounts of HNP 1-3 and LL-37 proteins in the cell culture supernatants were also determined by ELISA. In addition, NO levels in neutrophil culture supernatants were quantitated by the Griess reaction. Neutrophils from periodontitis patients cultured with Aa-LPS, Pg-LPS and Ec-LPS expressed higher HNP 1-3 mRNA than neutrophils from healthy subjects. LL-37 mRNA expression was higher in neutrophils from patients stimulated with Aa-LPS. Neutrophils from periodontitis patients produced significantly higher LL-37 protein levels than neutrophils from healthy subjects when stimulated with Pg-LPS and Ec-LPS, but no difference was observed in HNP 1-3 production. Neutrophils from periodontitis patients cultured or not with Pg-LPS and Ec-LPS produced significantly lower NO levels than neutrophils from healthy subjects. The significant differences in the production of LL-37 and NO between neutrophils from healthy and periodontitis subjects indicate that production of these molecules might influence individual susceptibility to important periodontal pathogens.
Assuntos
Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Peptídeos Catiônicos Antimicrobianos/biossíntese , Neutrófilos/metabolismo , Óxido Nítrico/biossíntese , Periodontite/imunologia , alfa-Defensinas/biossíntese , Estudos de Casos e Controles , Doença Crônica , Índice de Placa Dentária , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Lipopolissacarídeos , Neutrófilos/imunologia , Índice Periodontal , Periodontite/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Neutrophils play an important role in periodontitis by producing nitric oxide (NO) and antimicrobial peptides, molecules with microbicidal activity via oxygen-dependent and -independent mechanisms, respectively. It is unknown whether variation in the production of antimicrobial peptides such as LL-37, human neutrophil peptides (HNP) 1-3, and NO by neutrophils influences the pathogenesis of periodontal diseases. We compared the production of these peptides and NO by lipopolysaccharide (LPS)-stimulated neutrophils isolated from healthy subjects and from patients with periodontitis. Peripheral blood neutrophils were cultured with or without Aggregatibacter actinomycetemcomitans-LPS (Aa-LPS), Porphyromonas gingivalis-LPS (Pg-LPS) and Escherichia coli-LPS (Ec-LPS). qRT-PCR was used to determine quantities of HNP 1-3 and LL-37 mRNA in neutrophils. Amounts of HNP 1-3 and LL-37 proteins in the cell culture supernatants were also determined by ELISA. In addition, NO levels in neutrophil culture supernatants were quantitated by the Griess reaction. Neutrophils from periodontitis patients cultured with Aa-LPS, Pg-LPS and Ec-LPS expressed higher HNP 1-3 mRNA than neutrophils from healthy subjects. LL-37 mRNA expression was higher in neutrophils from patients stimulated with Aa-LPS. Neutrophils from periodontitis patients produced significantly higher LL-37 protein levels than neutrophils from healthy subjects when stimulated with Pg-LPS and Ec-LPS, but no difference was observed in HNP 1-3 production. Neutrophils from periodontitis patients cultured or not with Pg-LPS and Ec-LPS produced significantly lower NO levels than neutrophils from healthy subjects. The significant differences in the production of LL-37 and NO between neutrophils from healthy and periodontitis subjects indicate that production of these molecules might influence individual susceptibility to important periodontal pathogens.
Assuntos
Peptídeos Catiônicos Antimicrobianos/biossíntese , Neutrófilos/metabolismo , Óxido Nítrico/biossíntese , Periodontite/imunologia , alfa-Defensinas/biossíntese , Adulto , Estudos de Casos e Controles , Doença Crônica , Índice de Placa Dentária , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Humanos , Lipopolissacarídeos , Masculino , Pessoa de Meia-Idade , Neutrófilos/imunologia , Índice Periodontal , Periodontite/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
We have identified impaired neutrophils in elderly individuals which could be involved with Candida-related denture stomatitis (DS), an oral infection predominantly caused by Candida albicans, affecting especially elderly individuals using dental prosthesis. However, specific mechanisms performed by neutrophil contributing to the susceptibility of the elderly to DS are not fully understood. This study evaluated activation features of blood neutrophils from elderly and young individuals with DS. Blood neutrophils cultured with C. albicans from elderly subjects secreted decreased levels of CXCL8. However, C. albicans challenged-neutrophils from DS patients produced high IL-4 and IL-10, and low GM-CSF levels, regardless of age. Additional elastase activity of neutrophils from both elderly groups was detected after incubation with C. albicans, but only neutrophils from elderly DS demonstrated high myeloperoxidase activity. Therefore, DS patients have affected neutrophils, and the advance of age intensifies these damages. In summary, individuals with Candida-related denture stomatitis presented variation in the neutrophil phenotype and activation. Such alterations were more intense in neutrophils from infected elderly individuals.
Assuntos
Sangue/imunologia , Candida albicans/imunologia , Candidíase Bucal/imunologia , Ativação de Neutrófilo , Estomatite sob Prótese/imunologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Candida albicans/patogenicidade , Células Cultivadas , Citocinas/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Elastase Pancreática/metabolismo , Peroxidase/metabolismoRESUMO
Periodontal disease (PD) progression involves the selective leukocyte infiltration into periodontium, supposedly mediated by the chemokine/chemokine receptor system. In this study, we investigated the role of chemokine receptor CCR5 in the immunoregulation of experimental PD in C57BL/6 (WT) and CCR5KO mice. Aggregatibacter actinomycetem comitans infection triggered the chemoattraction of distinct CCR5+ leukocyte subpopulations (determined by flow cytometry): CCR5+F4/80+ leukocytes, which co-express CD14 , CCR2, TNF-α, and IL-1ß, indicative of activated macrophages; and CCR5+CD4+ cells, which co-express CXCR3, IFN-γ, and RANKL, indicative of Th1 lymphocytes, therefore comprising pro-osteoclastic and osteoclastogenic cell subsets, respectively. CCR5KO mice presented a lower PD severity (lower inflammation and alveolar bone loss) when compared with the WT strain, since the migration of F4/80+, TNF-α+, CD4+, and RANKL+ cells specifically decreased due to the lack of CCR5. Also, ELISA analysis demonstrated that the production of TNF-α, IL-1ß, IL-6, IFN-γ, and RANKL in periodontal tissues was significantly decreased in the CCR5KO strain. The periodontal bacterial load and antimicrobial patterns were unaltered in CCR5KO mice. Our results demonstrate that the chemokine receptor is involved in the migration of distinct leukocyte subpopulations throughout experimental PD, being a potential target for therapeutic intervention in PD.
Assuntos
Perda do Osso Alveolar/imunologia , Quimiotaxia de Leucócito/imunologia , Periodontite Crônica/imunologia , Osteoclastos/imunologia , Receptores CCR5/imunologia , Aggregatibacter actinomycetemcomitans/fisiologia , Perda do Osso Alveolar/metabolismo , Animais , Carga Bacteriana , Periodontite Crônica/metabolismo , Citocinas/biossíntese , Interferon gama/biossíntese , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ligante RANK/biossíntese , Receptores CCR5/biossíntese , Células Th1/imunologiaRESUMO
We previously showed that neutrophils from patients with Candida-related denture stomatitis exhibited damaged function, and the advance in age intensified this condition. Because such alterations had been determined in elderly people that were not denture wearers, the purpose of this study was to clarify functional and phenotypic characteristics of neutrophils from elderly denture wearers (EDW) and young denture wearers (YDW) without oral lesion. We enrolled 20 denture wearers (12 EDW and 8 YDW) and determined the positivity of Candida species on maxillary prosthesis and palate. Additionally, blood and salivary neutrophils were evaluated. Furthermore, cytokines and chemokines salivary levels were detected. YDW presented higher positivity of Candida albicans than elderly ones. However, blood neutrophils from EDW expressed less CXCR1, CD62L and CD11b and had lower C. albicans phagocytosis than YDW. Although myeloperoxidase and elastase activity was significantly higher in C. albicans-stimulated blood neutrophils from elderly, they produced high levels of IL-10 and low levels of Granulocyte macrophage-colony stimulating factor (GM-CSF). Despite apoptosis rate of salivary neutrophils was enhanced, these cells were at a high number in YDW. GM-CSF and IL10 were lower in saliva from elderly group. These data confirmed that ageing affects blood and salivary neutrophils and could predispose elderly to persistent oral infections.
Assuntos
Candidíase Bucal/metabolismo , Dentaduras , Neutrófilos/fisiologia , Saliva/citologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Anticorpos/sangue , Apoptose , Citocinas/metabolismo , Feminino , Citometria de Fluxo , Imunofluorescência , Humanos , Masculino , Pessoa de Meia-Idade , Necrose , Elastase Pancreática/metabolismo , Peroxidase/metabolismo , Fagocitose , Estatísticas não ParamétricasRESUMO
Periodontitis (PD) and rheumatoid arthritis (RA) have been found to be clinically associated and to share the chronic nature of the inflammatory reaction associated with bone resorption activity. However, the mechanisms underlying such association are unknown. Therefore, we examined the basis of Actinobacillus actinomycetemcomitans- and Porphyromonas gingivalis-induced PD and pristane-induced arthritis (PIA) interaction in mice. Higher severity PD in the genetically inflammation prone acute inflammatory reactivity maximum (AIRmax) mice strain was associated with higher levels of TNF-alpha, IL-1beta, IL-17, matrix metalloproteinase (MMP)-13, and RANKL, whereas PD/PIA co-induction resulted in even higher levels of IL-1beta, IFN-gamma, IL-17, RANKL, and MMP-13 levels. Conversely, PD/PIA co-induction in AIRmin strain did not alter the course of both pathologies. PIA/PD co-induction resulted in altered expression of T-cell subsets transcription factors expression, with T-bet and RORgamma levels being upregulated, whereas GATA-3 levels were unaltered. Interestingly, PIA induction resulted in alveolar bone loss, such response being highly dependent on the presence of commensal oral bacteria. No differences were found in PIA severity parameters by PD co-induction. Our results show that the interaction between experimental PD and arthritis in mice involves a shared hyper-inflammatory genotype and functional interferences in innate and adaptive immune responses.
Assuntos
Artrite Reumatoide/genética , Artrite Reumatoide/imunologia , Genótipo , Mediadores da Inflamação/fisiologia , Periodontite/genética , Periodontite/imunologia , Animais , Artrite Reumatoide/patologia , Inflamação/genética , Inflamação/imunologia , Inflamação/patologia , Mediadores da Inflamação/metabolismo , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/patologia , Camundongos , Camundongos Transgênicos , Periodontite/patologiaRESUMO
BACKGROUND AND OBJECTIVE: Inflammatory immune reactions that occur in response to periodontopathogens are thought to protect the host against infection, but may trigger periodontal destruction. However, the molecular and genetic mechanisms underlying host susceptibility to periodontal infection and to periodontitis development have still not been established in detail. MATERIAL AND METHODS: In this study, we examined the mechanisms that modulate the outcome of Aggregatibacter (Actinobacillus) actinomycetemcomitans-induced periodontal disease in mice mouse strains selected for maximal (AIRmax) or minimal (AIRmin) inflammatory reactions. RESULTS: Our results showed that AIRmax mice developed a more severe periodontitis than AIRmin mice in response to A. actinomycetemcomitans infection, and this periodontitis was characterized by increased alveolar bone loss and inflammatory cell migration to periodontal tissues. In addition, enzyme-linked immunosorbent assays demonstrated that the levels of the cytokines interleukin-1beta, tumor necrosis factor-alpha and interleukin-17 were higher in AIRmax mice, as were the levels of matrix metalloproteinase (MMP)-2, MMP-13 and receptor activator of nuclear factor-kappaB ligand (RANKL) mRNA levels. However, the more intense inflammatory immune reaction raised by the AIRmax strain, in spite of the higher levels of antimicrobial mediators myeloperoxidase and inducible nitric oxide synthase, did not enhance the protective immunity to A. actinomycetemcomitans infection, because both AIRmax and AIRmin strains presented similar bacterial loads in periodontal tissues. In addition, the AIRmax strain presented a trend towards higher levels of serum C-reactive protein during the course of disease. CONCLUSION: Our results demonstrate that the intensity of the inflammatory immune reaction is associated with the severity of experimental periodontitis, but not with the control of A. actinomycetemcomitans periodontal infection, suggesting that the occurrence of hyperinflammatory genotypes may not be an evolutionary advantage in the complex host-pathogen interaction observed in periodontal diseases.
Assuntos
Infecções por Actinobacillus/imunologia , Aggregatibacter actinomycetemcomitans/imunologia , Perda do Osso Alveolar/imunologia , Periodontite/imunologia , Perda do Osso Alveolar/microbiologia , Animais , Proteína C-Reativa/análise , Movimento Celular/fisiologia , Contagem de Colônia Microbiana , Suscetibilidade a Doenças/imunologia , Interações Hospedeiro-Patógeno , Interleucina-17/análise , Interleucina-1beta/análise , Contagem de Leucócitos , Leucócitos/imunologia , Masculino , Metaloproteinase 13 da Matriz/análise , Metaloproteinase 2 da Matriz/análise , Camundongos , Óxido Nítrico Sintase Tipo II/análise , Osteoprotegerina/análise , Periodontite/sangue , Periodontite/microbiologia , Peroxidase/análise , Ligante RANK/análise , Inibidor Tecidual de Metaloproteinase-1/análise , Inibidor Tecidual de Metaloproteinase-3/análise , Fator de Necrose Tumoral alfa/análiseRESUMO
BACKGROUND AND OBJECTIVE: Inflammatory cytokines such as tumor necrosis factor-alpha are involved in the pathogenesis of periodontal diseases. A high between-subject variation in the level of tumor necrosis factor-alpha mRNA has been verified, which may be a result of genetic polymorphisms and/or the presence of periodontopathogens such as Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola (called the red complex) and Aggregatibacter actinomycetemcomitans. In this study, we investigated the effect of the tumor necrosis factor-alpha (TNFA) -308G/A gene polymorphism and of periodontopathogens on the tumor necrosis factor-alpha levels in the periodontal tissues of nonsmoking patients with chronic periodontitis (n = 127) and in control subjects (n = 177). MATERIAL AND METHODS: The TNFA -308G/A single nucleotide polymorphism was investigated using polymerase chain reaction-restriction fragment length polymorphism analysis, whereas the tumor necrosis factor-alpha levels and the periodontopathogen load were determined using real-time polymerase chain reaction. RESULTS: No statistically significant differences were found in the frequency of the TNFA -308 single nucleotide polymorphism in control and chronic periodontitis groups, in spite of the higher frequency of the A allele in the chronic periodontitis group. The concomitant analyses of genotypes and periodontopathogens demonstrated that TNFA -308 GA/AA genotypes and the red-complex periodontopathogens were independently associated with increased levels of tumor necrosis factor-alpha in periodontal tissues, and no additive effect was seen when both factors were present. P. gingivalis, T. forsythia and T. denticola counts were positively correlated with the level of tumor necrosis factor-alpha. TNFA -308 genotypes were not associated with the periodontopathogen detection odds or with the bacterial load. CONCLUSION: Our results demonstrate that the TNFA -308 A allele and red-complex periodontopathogens are independently associated with increased levels of tumor necrosis factor-alpha in diseased tissues of nonsmoking chronic periodontitis patients and consequently are potentially involved in determining the disease outcome.
Assuntos
Adenina , Bacteroides/fisiologia , Periodontite Crônica/imunologia , Guanina , Polimorfismo de Nucleotídeo Único/genética , Porphyromonas gingivalis/fisiologia , Treponema denticola/fisiologia , Fator de Necrose Tumoral alfa/genética , Adulto , Aggregatibacter actinomycetemcomitans/fisiologia , Periodontite Crônica/microbiologia , Feminino , Frequência do Gene/genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Perda da Inserção Periodontal/imunologia , Perda da Inserção Periodontal/microbiologia , Bolsa Periodontal/imunologia , Bolsa Periodontal/microbiologia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Inflammatory immune reactions in response to periodontopathogens are thought to protect the host against infection, but may trigger periodontal destruction. Thus, we examined the mechanisms by which the proinflammatory cytokine tumour necrosis factor (TNF)-alpha modulates the outcome of Actinobacillus actinomycetemcomitans-induced periodontal disease in mice. Our results showed that TNF-alpha receptor p55-deficient mice [p55TNF-knock-out (KO)] developed a less severe periodontitis in response to A. actinomycetemcomitans infection, characterized by significantly less alveolar bone loss and inflammatory reaction. Real-time polymerase chain reaction (PCR) demonstrated that levels of chemokines (CXCL1, 3 and 10; CCL3 and 5) and their receptors (CXCR2 and 3, CCR5) were lower in p55TNF-KO mice, as were matrix metalloproteinase (MMP)-1, 2 and 9 and receptor activator of nuclear factor kB ligand (RANKL) mRNA levels. However, the absence of the TNF-alpha p55 results in an impairment of protective immunity to A. actinomycetemcomitans infection, characterized by increased bacterial load and higher levels of C-reactive protein during the course of disease. Such impaired host response may be the result of the reduced chemoattraction of lymphocytes, neutrophils and macrophages, and reduced inducible nitric oxide synthase expression (iNOS) and myeloperoxidase (MPO) production in periodontal tissues of p55 TNF-KO mice. Our results demonstrate the mechanisms involved determining periodontal disease severity by TNF-alpha receptor p55, and its role in providing immune protection to A. actinomycetemcomitans periodontal infection.
Assuntos
Infecções por Actinobacillus/imunologia , Aggregatibacter actinomycetemcomitans , Periodontite/imunologia , Periodonto/imunologia , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Receptores Chamariz do Fator de Necrose Tumoral/metabolismo , Infecções por Actinobacillus/patologia , Aggregatibacter actinomycetemcomitans/imunologia , Perda do Osso Alveolar , Animais , Anticorpos Antibacterianos/sangue , Proteína C-Reativa/análise , Quimiocina CCL5 , Quimiocina CXCL1 , Quimiocina CXCL10 , Quimiocinas CC/análise , Quimiocinas CC/genética , Quimiocinas CXC/análise , Quimiocinas CXC/genética , Primers do DNA/genética , Ensaio de Imunoadsorção Enzimática/métodos , Citometria de Fluxo , Interferon gama/análise , Interferon gama/genética , Interleucina-10/sangue , Interleucina-10/genética , Interleucina-1beta/análise , Interleucina-1beta/genética , Metaloproteinases da Matriz/análise , Metaloproteinases da Matriz/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Periodontite/patologia , Periodonto/patologia , Peroxidase/análise , Ligante RANK/análise , Ligante RANK/genética , Receptores CCR5/análise , Receptores CCR5/genética , Receptores CXCR3 , Receptores de Quimiocinas/análise , Receptores de Quimiocinas/genética , Receptores de Interleucina-8B/análise , Receptores de Interleucina-8B/genética , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Receptores Chamariz do Fator de Necrose Tumoral/imunologia , Fator de Necrose Tumoral alfa/imunologiaRESUMO
BACKGROUND AND OBJECTIVE: Inflammatory cytokines are thought to trigger periodontal tissue destruction. In addition to being regulated by anti-inflammatory mediators, their activity is under the control of suppressors of cytokine signaling (SOCS), which down-regulate the signal transduction as part of an inhibitory feedback loop. We therefore investigated the expression of SOCS-1, -2 and -3, and the cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-10, in different forms of human periodontal diseases. MATERIAL AND METHODS: Quantitative polymerase chain reaction (RealTime-PCR) was performed with mRNA from gingival biopsies of control subjects and from that of patients with chronic gingivitis and chronic periodontitis. RESULTS: Our results show that patients with chronic gingivitis and chronic periodontitis exhibit significantly higher SOCS-1, -2 and -3, TNF-alpha and interleukin-10 mRNA expression when compared with healthy controls. The data also demonstrate that SOCS-1 and -3 mRNA expression was higher in tissue from patients with chronic gingivitis than chronic periodontitis, while the levels of SOCS-2, TNF-alpha and interleukin-10 mRNA were similar in these groups. CONCLUSION: The increased expression of SOCS-1, -2 and -3 mRNA in diseased periodontal tissues is believed to be involved in the down-regulation of inflammatory cytokine and Toll-like receptor signaling, and therefore in the attenuation of both the inflammatory reaction and disease severity. Furthermore, it is possible that variation in the levels of SOCS mRNA expressed in different forms of periodontal diseases may determine the stable or progressive nature of the lesions.
Assuntos
Interleucina-10/análise , Periodontite/metabolismo , RNA Mensageiro/análise , Proteínas Supressoras da Sinalização de Citocina/análise , Fator de Necrose Tumoral alfa/análise , Adulto , Estudos de Casos e Controles , Progressão da Doença , Feminino , Gengivite/metabolismo , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
In the present study, we describe the ability of Trypanosoma cruzi trypomastigotes to stimulate the synthesis of beta-chemokines by macrophages. In vivo infection with T. cruzi led to MIP-1alpha, RANTES, and JE/MCP1 mRNA expression by cells from peritoneal inflammatory exudate. In addition, in vitro infection with T. cruzi resulted in expression of beta-chemokine MIP-1alpha, MIP-1beta, RANTES, and JE mRNA by macrophages. The expression of the beta-chemokine MIP-1alpha, MIP-1beta, RANTES, and JE proteins by murine macrophages cultured with trypomastigote forms of T. cruzi was confirmed by immunocytochemistry. Interestingly, macrophage infection with T. cruzi also resulted in NO production, which we found to be mediated mainly by beta-chemokines. Hence, treatment with anti-beta-chemokine-specific neutralizing antibodies partially inhibited NO release by macrophages incubated with T. cruzi parasites. Further, the addition of the exogenous beta-chemokines MIP-1alpha, MIP-1beta, RANTES, and JE/MCP-1 induced an increased T. cruzi uptake, leading to enhanced NO production and control of parasite replication in a dose-dependent manner. L-NMMA, a specific inhibitor of the L-arginine-NO pathway, caused a decrease in NO production and parasite killing when added to cultures of macrophages stimulated with beta-chemokines. Among the beta-chemokines tested, JE was more potent in inhibiting parasite growth, although it was much less efficient than gamma interferon (IFN-gamma). Nevertheless, JE potentiates parasite killing by macrophages incubated with low doses of IFN-gamma. Together, these results suggest that in addition to their chemotactic activity, murine beta-chemokines may also contribute to enhancing parasite uptake and promoting control of parasite replication in macrophages and may play a role in resistance to T. cruzi infection.
Assuntos
Quimiocina CCL2/biossíntese , Quimiocina CCL5/biossíntese , Proteínas Inflamatórias de Macrófagos/biossíntese , Macrófagos/parasitologia , Óxido Nítrico/biossíntese , Trypanosoma cruzi/imunologia , Animais , Células Cultivadas , Quimiocina CCL2/genética , Quimiocina CCL3 , Quimiocina CCL4 , Quimiocina CCL5/genética , Quimiocinas CC/biossíntese , Quimiocinas CC/genética , Feminino , Ativação de Macrófagos , Proteínas Inflamatórias de Macrófagos/genética , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C3H , Trypanosoma cruzi/crescimento & desenvolvimentoRESUMO
The activation of the nitric oxide (NO) production system and its involvement in the control of the lung fungal burden and in immunosuppression mechanisms were studied during the course of Paracoccidioides brasiliensis-infected mice. Mice that had been infected with the fungus were treated daily with a specific inhibitor of NO synthesis, N omega-nitro-L-arginine, or with buffered saline (control); NO production was assessed on the basis of spontaneous NO2- production by bronchoalveolar and peritoneal macrophages (Mphi) and of serum NO3- levels. The infection coursed with an elevation of NO3- levels. The Mphi produced NO2- and released TNF-alpha only after stimulation with LPS. In addition, the immunoproliferative responses of spleen cells that had been stimulated with the fungus Ag or with Con A were depressed. An examination of the lungs of infected animals showed a progressive increase in the size of the lesions. Treatment of the animals, which resulted in an inhibition of NO2- production by Mphi and a reduction of serum NO3- levels, caused the spontaneous release of TNF-alpha from infected animals and prevented the failure of the lymphoproliferative capacity of spleen cells. Furthermore, the treatment resulted in less pulmonary damage despite the fact that the lung fungal burden increased. It was also demonstrated that the NO donors S-nitroso-acetyl penicillamine and 3-morpholino-sydnonimine-hydrochloride were able to inhibit the growth of P. brasiliensis in vitro. These results suggest that although NO is important for the killing of the fungi, the activation of NO production in P. brasiliensis infection contributes to the occurrence of the immunosuppression observed during the course of the infection.