RESUMO
OBJECTIVES: This study evaluated the association between environmental factors and genetic variations in enzymes that metabolize antituberculosis (anti-TB) drugs [arylamine N-acetyltransferase 2, cytochrome P450 2E1 (CYP2E1), glutathione S-transferase theta 1 (GSTT1), and glutathione S-transferase mu 1] with antituberculosis drug-induced hepatotoxicity (ATDH). We also investigated the potential gene-gene and gene-environment interactions as well as their association with ATDH development in a population of hospitalized TB patients from Buenos Aires. PATIENTS AND METHODS: We investigated 364 TB patients who received anti-TB drugs. Physicians collected demographic and clinical data to identify environmental risk factors for ATDH development. Polymorphisms were detected using gene sequencing, PCR, and PCR-restriction fragment length polymorphisms. A binary logistic regression analysis was carried out to compare the results of TB patients with and without the development of hepatotoxicity. The multifactor dimensionality reduction method was used to examine genetic and environmental interactions in association with ATDH. RESULTS: This study suggests that the slow acetylator profile [odds ratio (OR): 3.02; 95% confidence interval (CI): 1.82-5.00; P<0.001], genotypes carrying the c2 variant (OR: 2.16; 95% CI: 1.33-3.51; P=0.002) or the A4 variant of CYP2E1 (OR: 2.13; 95% CI: 1.06-4.29; P=0.050), and female sex (OR: 1.94; 95% CI: 1.20-3.14; P=0.006) were independent predictor variables for ATDH. Patients carrying the slow acetylator profile and the c2 variant showed an increased risk (OR: 7.068; 95% CI: 3.34-14.95; P<0.001). We also identified a synergic interaction (epistasis) between GSTT1 and CYP2E1 associated with an increased risk for ATDH. A meaningful gene-environment interaction was associated with an increased risk of ATDH [testing balance accuracy=0.675 (P=0.001) and cross-validation consistency=10/10]. CONCLUSION: ATDH is a severe and prevalent adverse drug reaction and leads to drug discontinuation in 11% of TB patients. Our study created a prediction model that properly classified the 67.5% of TB patients in their risk of developing ATDH. The considerable number of TB patients in our country supports the use of pharmacogenetic testing and a comprehensive clinical history to identify patients with a high risk of suffering hepatotoxicity.
Assuntos
Antituberculosos/toxicidade , Epistasia Genética , Fígado/efeitos dos fármacos , Adulto , Feminino , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Adulto JovemRESUMO
Production of IFN-γ contributes to host defense against Mycobacterium tuberculosis (Mtb) infection. We previously demonstrated that Signaling lymphocytic activation molecule-associated protein (SAP) expression on cells from tuberculosis (TB) patients was inversely correlated with IFN-γ production. Here we first investigated the role of NK, T- and B-cell antigen (NTB-A)/SAP pathway in the regulation of Th1 response against Mtb. Upon antigen stimulation, NTB-A phosphorylation rapidly increases and afterwards modulates IFN-γ and IL-17 secretion. To sustain a healthy immune system, controlled expansion and contraction of lymphocytes, both during and after an adaptive immune response, is essential. Besides, restimulation-induced cell death (RICD) results in an essential homeostatic mechanism for precluding excess T-cell accumulation and associated immunopathology during the course of certain infections. Accordingly, we found that the NTB-A/SAP pathway was required for RICD during active tuberculosis. In low responder (LR) TB patients, impaired RICD was associated with diminished FASL levels, IL-2 production and CD25high expression after cell-restimulation. Interestingly, we next observed that SAP mediated the recruitment of the Src-related kinase FYNT, only in T cells from LR TB patients that were resistant to RICD. Together, we showed that the NTB-A/SAP pathway regulates T-cell activation and RICD during human TB. Moreover, the NTB-A/SAP/FYNT axis promotes polarization to an unfavorable Th2-phenotype.
Assuntos
Mycobacterium tuberculosis/imunologia , Família de Moléculas de Sinalização da Ativação Linfocitária/metabolismo , Células Th2/imunologia , Tuberculose/imunologia , Adulto , Morte Celular , Diferenciação Celular , Células Cultivadas , Feminino , Homeostase , Humanos , Imunidade , Terapia de Imunossupressão , Interferon gama/metabolismo , Interleucina-17/metabolismo , Ativação Linfocitária , Masculino , Proteínas de Neoplasias/metabolismo , Proteínas Tirosina Quinases/metabolismo , Transdução de SinaisRESUMO
INTRODUCTION: It has been widely reported that the slow acetylator phenotype of N-acetyltransferase 2 (NAT2) is associated with the development of antituberculosis drug-induced hepatotoxicity (ATDH). The aim of this report was to evaluate the level of agreement and accuracy of two recently recommended markers, the two-single nucleotide polymorphisms (SNP) (C282T and T341C) and tagSNP of NAT2 (rs1495741) genotypes, to predict the seven-SNP-inferred NAT2 phenotype in Bolivian and Argentinian tuberculosis (TB)-patient populations. In addition, we analyzed the association of these markers with ATDH. METHODS: We examined 331 TB patients who had been treated with anti-TB drugs. TagSNP of NAT2 genotyping was determined using PCR-restriction fragment length polymorphisms. The seven SNPs of NAT2 were determined using sequencing. Concordance analysis was carried out using Kendall's tau-b coefficient (w) and the degree of agreement with Cohen's κ coefficient (κ). Receiver operating characteristic receiver operating characteristic curves were obtained to measure the specificity and sensitivity of the method. A binary logistic regression was performed to identify variables associated with the development of ATDH. RESULTS: Both predictors showed a remarkable concordance (>95.0%) and an almost perfect agreement (κ>0.945; P<0.0001) with the predicted acetylator profile. However, the sensitivity of the tagSNP genotypes to predict the NAT2 acetylator phenotype was lower in the Bolivian population (92.3%) compared with the Argentinian population (100.0%). CONCLUSION: A nearly perfect agreement between both predictors and the predicted acetylation profile was observed with very high levels of sensitivity (>97%) and specificity (>98.0%). Furthermore, and as expected, both the two-SNP (C282T, T341C) and tagSNP were found to be independent variables in predicting ATDH with the same strength as seven-SNP of NAT2.
Assuntos
Antituberculosos/efeitos adversos , Arilamina N-Acetiltransferase/genética , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Polimorfismo de Nucleotídeo Único/genética , Tuberculose/tratamento farmacológico , Acetilação , Adulto , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium/efeitos dos fármacos , Tuberculose/microbiologia , Adulto JovemRESUMO
Interferon (IFN)-γ displays a critical role in tuberculosis (TB), modulating the innate and adaptive immune responses. Previously, we reported that secretory leukocyte protease inhibitor (SLPI) is a pattern recognition receptor with anti-mycobacterial activity against Mycobacterium tuberculosis (Mtb). Herein, we determined whether IFN-γ modulated the levels of SLPI in TB patients. Plasma levels of SLPI and IFN-γ were studied in healthy donors (HDs) and TB patients. Peripheral blood mononuclear cells from HDs and patients with TB or defective IFN-γ receptor 1* were stimulated with Mtb antigen and SLPI, and IFN-γR expression levels were measured. Both SLPI and IFN-γ were significantly enhanced in plasma from those with TB compared with HDs. A direct association between SLPI levels and the severity of TB was detected. In addition, Mtb antigen stimulation decreased the SLPI produced by peripheral blood mononuclear cells from HDs, but not from TB or IFN-γR patients. Neutralization of IFN-γ reversed the inhibition of SLPI induced by Mtb antigen in HDs, but not in TB patients. Furthermore, recombinant IFN-γ was unable to modify the expression of SLPI in TB patients. Finally, IFN-γR expression was lower in TB compared with HD peripheral blood mononuclear cells. These results show that Mtb-induced IFN-γ down-modulated SLPI levels by signaling through the IFN-γR in HDs. This inhibitory mechanism was not observed in TB, probably because of the low expression of IFN-γR detected in these individuals.
Assuntos
Interferon gama/metabolismo , Inibidor Secretado de Peptidases Leucocitárias/metabolismo , Índice de Gravidade de Doença , Tuberculose/metabolismo , Tuberculose/patologia , Adulto , Estudos de Casos e Controles , Humanos , Interferon gama/sangue , Inibidor Secretado de Peptidases Leucocitárias/sangue , Tuberculose/sangueRESUMO
Tuberculosis (TB) is one of the world's most pernicious diseases mainly due to immune evasion strategies displayed by its causative agent Mycobacterium tuberculosis (Mtb). Blood monocytes (Mos) represent an important source of DCs during chronic infections; consequently, the alteration of their differentiation constitutes an escape mechanism leading to mycobacterial persistence. We evaluated whether the CD16(+)/CD16(-) Mo ratio could be associated with the impaired Mo differentiation into DCs found in TB patients. The phenotype and ability to stimulate Mtb-specific memory clones DCs from isolated Mo subsets were assessed. We found that CD16(-) Mos differentiated into CD1a(+) DC-SIGN(high) cells achieving an efficient recall response, while CD16(+) Mos differentiated into a CD1a(-) DC-SIGN(low) population characterized by a poor mycobacterial Ag-presenting capacity. The high and sustained phosphorylated p38 expression observed in CD16(+) Mos was involved in the altered DC profile given that its blockage restored DC phenotype and its activation impaired CD16(-) Mo differentiation. Furthermore, depletion of CD16(+) Mos indeed improved the differentiation of Mos from TB patients toward CD1a(+) DC-SIGN(high) DCs. Therefore, Mos from TB patients are less prone to differentiate into DCs due to their increased proportion of CD16(+) Mos, suggesting that during Mtb infection Mo subsets may have different fates after entering the lungs.
Assuntos
Células Dendríticas/patologia , Monócitos/patologia , Receptores de IgG/metabolismo , Tuberculose/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Adulto , Antígenos CD1/imunologia , Antígenos CD1/metabolismo , Diferenciação Celular/imunologia , Células Dendríticas/enzimologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Feminino , Proteínas Ligadas por GPI/imunologia , Proteínas Ligadas por GPI/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Monócitos/enzimologia , Monócitos/imunologia , Monócitos/metabolismo , Mycobacterium tuberculosis/imunologia , Receptores de IgG/imunologia , Transdução de Sinais/imunologia , Transdução de Sinais/fisiologia , Tuberculose/enzimologia , Tuberculose/metabolismo , Tuberculose/microbiologia , Adulto Jovem , Proteínas Quinases p38 Ativadas por Mitógeno/imunologiaRESUMO
DTH (delayed type hypersensitivity) reactions are secondary cellular immune responses that appear 24-72 h after antigen exposure. Tuberculous pleurisy is a common manifestation of extrapulmonary TB (tuberculosis) and is considered a human model of Th1-mediated DTH. In order to identify functional cross-talk among cellular populations sited in this inflammatory microenvironment, we analysed phenotypic and functional features of human B-cells isolated from the PF (pleural fluid) of TB patients. Freshly isolated PF-B-cells displayed a lower expression of CD20, CD1d and HLA-DR, and a higher expression of CD95, CD38, CD25, CXCR3 (CXC chemokine receptor 3) and CXCR4 (CXC chemokine receptor 4) than their PB (peripheral blood) counterparts, suggesting a non-classical in situ activation. Although memory PF-T-cell frequencies were increased, the frequencies of memory PF-B-cells were not. We demonstrated that, upon stimulation with γ-irradiated M. tuberculosis, mycobacterially secreted proteins or a lectin mitogen, PF-B-cells had a strong activation and produced IL-10 by a mechanism that was dependent on bystander activation of CD19(-) PF cells. Besides, within PF cells, B-cells diminished in vitro M. tuberculosis-induced IFN (interferon)-γ production by T-cells and NK (natural killer) cells in an IL-10-dependent manner. Finally, we found that the lower the frequency of B-cells, the higher the ratio of IFN-γ/IL-10 within PF. Thus our results suggest that B-cells can regulate a human DTH reaction induced by M. tuberculosis.
Assuntos
Linfócitos B/metabolismo , Hipersensibilidade Tardia/imunologia , Interferon gama/biossíntese , Células Matadoras Naturais/metabolismo , Linfócitos T/metabolismo , Tuberculose Pleural/microbiologia , Linfócitos B/imunologia , Humanos , Imunidade Celular/imunologia , Interleucina-10/imunologia , Células Matadoras Naturais/imunologia , Mycobacterium tuberculosis/imunologia , Linfócitos T/imunologia , Tuberculose Pleural/imunologiaRESUMO
Immune control of Mycobacterium tuberculosis depends on interferon γ (IFN-γ)-producing CD4(+) lymphocytes. Previous studies have shown that T cells from patients with tuberculosis produce less IFN-γ, compared with healthy donors, in response to mycobacterial antigens, although IFN-γ responses to mitogens are preserved. In this work, we found that M. tuberculosis-induced IFN-γ production by human T cells correlated with phosphorylation of the mitogen-activated protein kinases (MAPKs), extracellular signal-regulated kinase (ERK), and p38. Moreover, the majority of IFN-γ-producing T cells expressed signaling lymphocyte activation molecule (SLAM), and SLAM activation further increased ERK phosphorylation. Interestingly, patients with tuberculosis had delayed activation of ERK and p38, and this was most marked in patients with the poorest IFN-γ responses (ie, low responders). Besides, SLAM signaling failed to phosphorylate ERK in low responders. Our findings suggest that activation of p38 and ERK, in part through SLAM, mediates T-cell IFN-γ production in response to M. tuberculosis, a pathway that is defective in patients with tuberculosis.
Assuntos
MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Interferon gama/biossíntese , Mycobacterium tuberculosis/imunologia , Linfócitos T/imunologia , Tuberculose Pulmonar/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Antígenos CD/metabolismo , Ativação Enzimática , Humanos , Fosforilação , Receptores de Superfície Celular/metabolismo , Transdução de Sinais , Membro 1 da Família de Moléculas de Sinalização da Ativação Linfocitária , Tuberculose Pulmonar/metabolismo , Tuberculose Pulmonar/microbiologiaRESUMO
BACKGROUND AND AIM: Treatment with antituberculosis (TB) drugs produces liver damage in a large proportion of patients. Isoniazid, an antibacterial drug, is primarily responsible for this hepatotoxicity. Several polymorphisms of the N-acetyltransferase 2 (NAT-2) and cytochrome P450 2E1 enzymes, which are involved in the metabolism of isoniazid, may be directly associated with the development of hepatotoxicity. This study was designed to analyze the association between the NAT-2 and CYP2E1 polymorphisms with the development of anti-TB drug-induced hepatotoxicity (ATDH). METHODS: One hundred and seventy-five TB patients who had been treated with anti-TB drugs were studied. The allelic and genotypic frequency distributions of the NAT-2 and CYP2E1 enzymes were studied using polymerase chain reaction-restriction fragment length polymorphisms methodology. A binary logistic regression analysis was used to compare the results between TB patients with and without the development of hepatotoxicity. RESULTS: Having a slow acetylator status (odds ratio [OR] = 2.615; confidence interval [CI] = 1.264-5.411; P = 0.01), being female (OR = 2.734; CI = 1.325-5.639, P = 0.006), and having Bolivian ethnicity (OR = 2.711; CI = 1.307-6.625, P = 0.007) were found to be independent predictor variables for ATDH. CONCLUSIONS: This study showed that a patient's NAT-2 acetylator status, gender, and ethnic origin may be regarded as important risk factors for developing hepatotoxicity. Contrary to expectations, the CYP2E1 c1/c2 polymorphism did not show a significant association with hepatotoxicity in this study. Given the increases in TB cases and ATDH incidence levels, as well as the associated hospitalization costs, it may also be helpful to know patients' acetylator status prior to or at the beginning of the TB treatment regimen.
Assuntos
Antituberculosos/efeitos adversos , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Acetilação , Adulto , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Antituberculosos/metabolismo , Argentina/epidemiologia , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , Bolívia/etnologia , Doença Hepática Induzida por Substâncias e Drogas/etnologia , Doença Hepática Induzida por Substâncias e Drogas/genética , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Distribuição de Qui-Quadrado , Estudos Transversais , Citocromo P-450 CYP2E1/genética , Citocromo P-450 CYP2E1/metabolismo , Etnicidade , Feminino , Frequência do Gene , Genótipo , Humanos , Modelos Logísticos , Masculino , Razão de Chances , Fenótipo , Polimorfismo Genético , Polimorfismo de Fragmento de Restrição , Estudos Prospectivos , Fatores de Risco , Fatores Sexuais , Adulto JovemRESUMO
Protective immunity against Mycobacterium tuberculosis is primarily mediated by the interaction of antigen-specific T cells and antigen presenting cells, which often depends on the interplay of cytokines produced by these cells. Costimulatory signals represent a complex network of receptor-ligand interactions that qualitatively and quantitatively influence immune responses. Thus, here we investigated the function of CD137 and CD137L, molecules known to have a central role in immune regulation, during human tuberculosis (TB). We demonstrated that M. tuberculosis antigen stimulation increased both CD137 and CD137L expression on monocytes and NK cells from TB patients and healthy donors, but only up-regulated CD137 on T lymphocytes. Blockage of the CD137 pathway enhanced the levels of interferon (IFN)-γ and tumor necrosis factor (TNF)-α produced by monocytes and NK against M. tuberculosis. In contrast, CD137 blockage significantly decreased the specific degranulation of CD8(+) T cells and the percentage of specific IFN-γ and TNF-α producing lymphocytes against the pathogen. Furthermore, inhibition of the CD137 pathway markedly increased T-cell apoptosis. Taken together, our results demonstrate that CD137:CD137L interactions regulate the innate and adaptive immune response of the host against M. tuberculosis.
Assuntos
Imunidade Adaptativa , Imunidade Inata , Mycobacterium tuberculosis/imunologia , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologia , Ligante 4-1BB/metabolismo , Células Cultivadas , Humanos , Células Matadoras Naturais/imunologia , Linfócitos T/imunologia , Tuberculose/imunologiaRESUMO
A case of a 20-year-old man with multilevel non-contiguous tuberculous spondylitis (cervical, dorsal 6, dorsal 10 and lumbar) is presented. In the context of disseminated tuberculosis in an HIV-negative patient with serious compromise of his general condition and multiple locations of the disease, some of these with fistulas that secreted caseum. The acute paraplegia led, considering the sensory level at dorsal 6, to a first urgent decompression surgery via the posterior approach. A scheduled surgery was then performed, first in the cervical region via the anterior approach, with corpectomy, placement of a vertebral body replacement plus autologous graft and plate with screws. Subsequently, dislocation of dorsal level 6 was evidenced backwards, compressing the spinal cord and, given the mechanical instability, a third surgical stage was indicated by posterior approach, which included reduction, decompression and fixation, resolving the three levels by posterior approach with bars and screws. The surgical, medical and physiotherapy treatment of this rare form of Pott's disease was successful, with recovery of his mechanical stability and progressive recovery of his neurological status. The surgical, medical and physiotherapy treatment of this rare form of Pott's disease was successful, with recovery of his mechanical stability and progressive recovery of his neurological status.
Se presenta el caso de un varón de 20 años con espondilitis tuberculosa multinivel no contigua (cervical, dorsal 6, dorsal 10 y lumbar). Se trata de un paciente HIV negativo con tuberculosis diseminada con grave compromiso de su estado general y múltiples localizaciones de la enfermedad. Algunas tenían fistulas que secretaban caseum. El paciente presentó paraplejía aguda que requirió, teniendo en cuenta el nivel sensitivo a nivel dorsal 6, una primera cirugía urgente de descompresión por vía posterior. Luego se efectuó la cirugía programada. En primera instancia, la región cervical por vía anterior, con corporectomía, colocación de reemplazo de cuerpo vertebral más injerto autólogo y placa con tornillos. Posteriormente se evidenció luxación del nivel dorsal 6 hacia atrás comprimiendo la médula espinal y, dada la inestabilidad mecánica, se indicó un tercer tiempo quirúrgico por vía posterior que comprendió reducción, descompresión y fijación, resolviendo los tres niveles por vía posterior con barras y tornillos. El tratamiento quirúrgico, médico y kinésico de esta forma poco frecuente del mal de Pott fue exitoso, con recuperación de su estabilidad mecánica y progresiva recuperación de su estado neurológico.
Assuntos
Tuberculose da Coluna Vertebral , Masculino , Humanos , Adulto Jovem , Adulto , Tuberculose da Coluna Vertebral/complicações , Tuberculose da Coluna Vertebral/diagnóstico por imagem , Tuberculose da Coluna Vertebral/cirurgia , Vértebras Torácicas/cirurgiaRESUMO
Tuberculous pleurisy allows the study of specific cells at the site of Mycobacterium tuberculosis infection. Among pleural lymphocytes, natural killer (NK) cells are a major source of interferon gamma (IFN-gamma), and their functions are regulated by activating and inhibitory receptors. Programmed death-1 (PD-1), programmed death ligand 1 (PD-L1), and programmed death ligand 2 (PD-L2) are recognized inhibitory receptors in adaptive immunity, but their role during innate immunity remains poorly understood. We investigated the PD-1:PD-L1/PD-L2 pathway on NK cell effector functions in peripheral blood and pleural fluid from patients with tuberculosis. M. tuberculosis stimulation significantly up-regulated PD-1, PD-L1, and PD-L2 levels on NK cells. Interestingly, a direct correlation between PD-1 and IFN-gamma expression on NK cells was observed. Moreover, blockade of the PD-1 pathway markedly augmented lytic degranulation and IFN-gamma production of NK cells against M. tuberculosis. Furthermore, PD-1(+) NK cells displayed a diminished IFN-gamma mean fluorescence intensity, denoting the relevance of PD-1 on IFN-gamma regulation. Together, we described a novel inhibitory role played by PD-1:PD-L interactions in innate immunity in tuberculosis.
Assuntos
Antígenos CD/imunologia , Proteínas Reguladoras de Apoptose/imunologia , Apoptose , Imunidade Inata , Mycobacterium tuberculosis/imunologia , Tuberculose/imunologia , Tuberculose/patologia , Adulto , Antígeno B7-H1 , Sangue/imunologia , Perfilação da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/imunologia , Interferon gama/antagonistas & inibidores , Interferon gama/metabolismo , Células Matadoras Naturais/imunologia , Pleura/imunologia , Proteína 2 Ligante de Morte Celular Programada 1 , Receptor de Morte Celular Programada 1 , Regulação para CimaRESUMO
Tuberculous pleurisy, one of the most common manifestations of extrapulmonary tuberculosis, is characterized by a T-cell-mediated hypersensitivity reaction along with a Th1 immune profile. In this study, we investigated functional cross-talk among T and NK cells in human tuberculous pleurisy. We found that endogenously activated pleural fluid-derived NK cells express high ICAM-1 levels and induce T-cell activation ex vivo through ICAM-1. Besides, upon in vitro stimulation with monokines and PAMP, resting peripheral blood NK cells increased ICAM-1 expression leading to cellular activation and Th1 polarization of autologous T cells. Furthermore, these effects were abolished by anti-ICAM-1 Ab. Hence, NK cells may contribute to the adaptive immune response by a direct cell-contact-dependent mechanism in the context of Mycobacterium tuberculosis infection.
Assuntos
Molécula 1 de Adesão Intercelular/metabolismo , Células Matadoras Naturais/imunologia , Mycobacterium tuberculosis , Linfócitos T/imunologia , Tuberculose Pleural/imunologia , Adulto , Antígeno CD11a/imunologia , Antígeno CD56/imunologia , Comunicação Celular/imunologia , Cisteína/análogos & derivados , Cisteína/farmacologia , Humanos , Molécula 1 de Adesão Intercelular/efeitos dos fármacos , Molécula 1 de Adesão Intercelular/imunologia , Interleucina-12/farmacologia , Interleucina-15/farmacologia , Interleucina-18/farmacologia , Lipopolissacarídeos/farmacologia , Lipoproteínas/farmacologia , Pessoa de Meia-Idade , Fosfotransferases (Aceptor do Grupo Fosfato)RESUMO
During a chronic infection such as tuberculosis, the pool of tissue dendritic cells (DC) must be renewed by recruitment of both circulating DC progenitors and monocytes (Mo). However, the microenvironment of the inflammatory site affects Mo differentiation. As DC are critical for initiating a Mycobacterium tuberculosis-specific T-cell response, we argue that interference of M. tuberculosis with a correct DC generation would signify a mechanism of immune evasion. In this study, we showed that early interaction of γ-irradiated M. tuberculosis with Mo subverts DC differentiation in vitro. We found that irradiated M. tuberculosis effect involves (1) the loss of a significant fraction of monocyte population and (2) an altered differentiation process of the surviving monocyte subpopulation. Moreover, in the absence of irradiated M. tuberculosis, DC consist in a major DC-specific intercellular adhesion molecule 3-grabbing non-integrin receptor (DC-SIGN(high))/CD86(low) and minor DC-SIGN(low)/CD86(high) subpopulations, whereas in the presence of bacteria, there is an enrichment of DC-SIGN(low)/CD86(high) population. Besides, this population enlarged by irradiated M. tuberculosis, which is characterized by a reduced CD1b expression, correlates with a reduced induction of specific T-lymphocyte proliferation. The loss of CD1molecules partially involves toll-like receptors (TLR-2)/p38 MAPK activation. Finally, several features of Mo, which have been differentiated into DC in the presence of irradiated M. tuberculosis, resemble the features of DC obtained from patients with active tuberculosis. In conclusion, we suggest that M. tuberculosis escapes from acquired immune response in tuberculosis may be caused by an altered differentiation into DC leading to a poor M. tuberculosis-specific T-cell response.
Assuntos
Células Dendríticas/imunologia , Células Dendríticas/microbiologia , Adulto , Antígenos CD1/metabolismo , Antígeno B7-2/metabolismo , Moléculas de Adesão Celular/metabolismo , Diferenciação Celular/imunologia , Proliferação de Células , Células Cultivadas , Humanos , Interleucina-10/metabolismo , Lectinas Tipo C/metabolismo , Teste de Cultura Mista de Linfócitos , Macrófagos/imunologia , Receptor de Manose , Lectinas de Ligação a Manose/metabolismo , Pessoa de Meia-Idade , Mycobacterium tuberculosis/patogenicidade , Receptores de Superfície Celular/metabolismo , Receptor 2 Toll-Like/metabolismo , Tuberculose/imunologia , Tuberculose/fisiopatologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
RATIONALE: Human secretory leukocyte protease inhibitor (SLPI) displays bactericidal activity against pathogens such as Escherichia coli and Streptococcus. Furthermore, it has been reported that murine SLPI shows potent antimycobacterial activity. OBJECTIVES: The aim of the present study was to investigate whether human recombinant SLPI not only kills mycobacteria but also acts as a pattern recognition receptor for the host immune system. METHODS: For the in vivo experiment, BALB/c mice were infected by intranasal instillation with Mycobacterium bovis BCG and viable BCG load in lung homogenates was later determined. For the in vitro experiments, SLPI was incubated overnight with a suspension of M. bovis BCG or the virulent strain Mycobacterium tuberculosis H37Rv, and the percentage survival as well as the binding of SLPI to mycobacteria was determined. Furthermore, bacteria phagocytosis was also determined by flow cytometry. MEASUREMENTS AND MAIN RESULTS: Intranasal SLPI treatment decreased the number of colony-forming units recovered from lung homogenates, indicating that SLPI interfered with M. bovis BCG infection. Moreover, SLPI decreased the viability of both M. bovis BCG and H37Rv. We demonstrated that SLPI attached to the surface of the mycobacteria by binding to pathogen-associated molecular pattern mannan-capped lipoarabinomannans and phosphatidylinositol mannoside. Furthermore, we found that in the sputum of patients with tuberculosis, mycobacteria were coated with endogenous SLPI. Finally, we showed that phagocytosis of SLPI-coated mycobacteria was faster than that of uncoated bacteria. CONCLUSIONS: The present results demonstrate for the first time that human SLPI kills mycobacteria and is a new pattern recognition receptor for them.
Assuntos
Mycobacterium tuberculosis/fisiologia , Inibidor Secretado de Peptidases Leucocitárias/metabolismo , Tuberculose Pulmonar/metabolismo , Animais , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Fagocitose , Escarro/química , Escarro/microbiologia , Tuberculose Pulmonar/imunologia , Tuberculose Pulmonar/microbiologiaRESUMO
Resumen Se presenta el caso de un varón de 20 años con espondilitis tuberculosa multinivel no contigua (cervical, dorsal 6, dorsal 10 y lumbar). Se trata de un paciente HIV negativo con tuberculosis dise minada con grave compromiso de su estado general y múltiples localizaciones de la enfermedad. Algunas tenían fistulas que secretaban caseum. El paciente presentó paraplejía aguda que requirió, teniendo en cuenta el nivel sensitivo a nivel dorsal 6, una primera cirugía urgente de descompresión por vía posterior. Luego se efectuó la cirugía programada. En primera instancia, la región cervical por vía anterior, con corporectomía, colocación de reemplazo de cuerpo vertebral más injerto autólogo y placa con tornillos. Posteriormente se evidenció luxación del nivel dorsal 6 hacia atrás comprimiendo la médula espinal y, dada la inestabilidad mecánica, se indicó un tercer tiempo quirúrgico por vía posterior que comprendió reducción, descompresión y fijación, resolviendo los tres niveles por vía posterior con barras y tornillos. El tratamiento quirúrgico, médico y kinésico de esta forma poco frecuente del mal de Pott fue exitoso, con recuperación de su estabilidad mecánica y progresiva recuperación de su estado neurológico.
Abstract A case of a 20-year-old man with multilevel non-contiguous tuberculous spondylitis (cervical, dorsal 6, dorsal 10 and lumbar) is presented. In the context of disseminated tuberculosis in an HIV-negative patient with serious compromise of his general condition and multiple locations of the disease, some of these with fistulas that secreted caseum. The acute paraplegia led, considering the sensory level at dorsal 6, to a first urgent decompression surgery via the posterior approach. A scheduled surgery was then performed, first in the cervical region via the anterior approach, with corpectomy, placement of a vertebral body replace ment plus autologous graft and plate with screws. Subsequently, dislocation of dorsal level 6 was evidenced backwards, compressing the spinal cord and, given the mechanical instability, a third surgical stage was indi cated by posterior approach, which included reduction, decompression and fixation, resolving the three levels by posterior approach with bars and screws. The surgical, medical and physiotherapy treatment of this rare form of Pott's disease was successful, with recovery of his mechanical stability and progressive recovery of his neurological status. The surgical, medical and physiotherapy treatment of this rare form of Pott's disease was successful, with recovery of his mechanical stability and progressive recovery of his neurological status.
RESUMO
IFN-γ release assays (IGRAs) are better indicators of Mycobacterium tuberculosis infection than the tuberculin skin test (TST) in Bacillus Calmette-Guérin (BCG)-vaccinated populations. However, IGRAs do not discriminate active and latent infections (LTBI) and no gold standard for LTBI diagnosis is available. Thus, since improved tests to diagnose M. tuberculosis infection are required, we assessed the efficacy of several M. tuberculosis latency antigens. BCG-vaccinated healthy donors (HD) and tuberculosis (TB) patients were recruited. QuantiFERON-TB Gold In-Tube, TST and clinical data were used to differentiate LTBI. IFN-γ production against CFP-10, ESAT-6, Rv2624c, Rv2626c and Rv2628 antigens was tested in peripheral blood mononuclear cells. LTBI subjects secreted significantly higher IFN-γ levels against Rv2626c than HD. Additionally, Rv2626c peptide pools to which only LTBI responded were identified, and their cumulative IFN-γ response improved LTBI discrimination. Interestingly, whole blood stimulation with Rv2626c allowed the discrimination between active and latent infections, since TB patients did not secrete IFN-γ against Rv2626c, in contrast to CFP-10 + ESAT-6 stimulation that induced IFN-γ response from both LTBI and TB patients. ROC analysis confirmed that Rv2626c discriminated LTBI from HD and TB patients. Therefore, since only LTBI recognizes specific epitopes from Rv2626c, this antigen could improve LTBI diagnosis, even in BCG-vaccinated people.
Assuntos
Antígenos de Bactérias/imunologia , Interferon gama/imunologia , Leucócitos Mononucleares/imunologia , Mycobacterium bovis/imunologia , Mycobacterium tuberculosis/imunologia , Vacinas contra a Tuberculose/administração & dosagem , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vacinas contra a Tuberculose/imunologiaRESUMO
Protective immunity against Mycobacterium tuberculosis (Mtb) requires IFNG. Besides, IFNG-mediated induction of autophagy suppresses survival of virulent Mtb in macrophage cell lines. We investigated the contribution of autophagy to the defense against Mtb antigen (Mtb-Ag) in cells from tuberculosis patients and healthy donors (HD). Patients were classified as high responders (HR) if their T cells produced significant IFNG against Mtb-Ag; and low responders (LR) when patients showed weak or no T cell responses to Mtb-Ag. The highest autophagy levels were detected in HD cells whereas the lowest quantities were observed in LR patients. Interestingly, upon Mtb-Ag stimulation, we detected a positive correlation between IFNG and MAP1LC3B-II/LC3-II levels. Actually, blockage of Mtb-Ag-induced IFNG markedly reduced autophagy in HR patients whereas addition of limited amounts of IFNG significantly increased autophagy in LR patients. Therefore, autophagy collaborates with human immune responses against Mtb in close association with specific IFNG secreted against the pathogen.
Assuntos
Antígenos de Bactérias/imunologia , Autofagia/efeitos dos fármacos , Interferon gama/metabolismo , Interferon gama/farmacologia , Mycobacterium tuberculosis/imunologia , Tuberculose/tratamento farmacológico , Autofagia/imunologia , Feminino , Humanos , Macrófagos/imunologia , Macrófagos/microbiologia , Masculino , Células Th1/efeitos dos fármacos , Células Th1/imunologia , Tuberculose/imunologiaAssuntos
Aspergilose/diagnóstico por imagem , Aspergillus fumigatus/isolamento & purificação , Pneumopatias Fúngicas/diagnóstico por imagem , Adulto , Aspergilose/diagnóstico , Aspergilose/microbiologia , Diagnóstico Diferencial , Humanos , Pneumopatias Fúngicas/diagnóstico , Pneumopatias Fúngicas/microbiologia , Masculino , Escarro/microbiologia , Tomografia Computadorizada por Raios X , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico por imagemRESUMO
INTRODUCTION: Arylamine N-acetyltransferase-2 (NAT-2) is a key human enzyme in drug detoxification and elimination. Mutations in NAT-2 affect the activity of anti-tuberculosis drugs and result in three different phenotypes: rapid (RA), intermediate (IA) and slow acetylators (SA). METHODOLOGY: The allelic, genotypic and phenotypic frequencies of NAT-2 were studied in 185 patients from Buenos Aires by restriction fragment length polymorphism. RESULTS: The following allele frequencies were obtained: *4 = 29.9%, *5 = 37.0, *6 = 25.6%, *7 = 8% and *14 = 1.3%. With regard to the phenotype, we observed that 53.6% of the population was SA, 35.7% was IA and 10.7% was RA. CONCLUSION: A high prevalence of SA might have an impact on anti-TB drug-induced hepatotoxicity.
Assuntos
Antituberculosos/metabolismo , Arilamina N-Acetiltransferase/genética , Frequência do Gene , Antituberculosos/efeitos adversos , Argentina , Genótipo , Humanos , Polimorfismo de Fragmento de RestriçãoRESUMO
Th1 lymphocytes are crucial in the immune response against Mycobacterium tuberculosis. Nevertheless, IFN-γ alone is not sufficient in the complete eradication of the bacteria, suggesting that other cytokines might be required for pathogen removal. Th17 cells have been associated with M. tuberculosis infection, but the role of IL-17-producing cells in human TB remains to be understood. Therefore, we investigated the induction and regulation of IFN-γ and IL-17 during the active disease. TB patients were classified as High and Low Responder individuals according to their T cell responses against the antigen, and cytokine expression upon M. tuberculosis stimulation was investigated in peripheral blood and pleural fluid. Afterwards, the potential correlation among the proportions of cytokine-producing cells and clinical parameters was analyzed. In TB patients, M. tuberculosis induced IFN-γ and IL-17, but in comparison with BCG-vaccinated healthy donors, IFN-γ results were reduced significantly, and IL-17 was markedly augmented. Moreover, the main source of IL-17 was represented by CD4(+)IFN-γ(+)IL-17(+) lymphocytes, a Th1/Th17 subset regulated by IFN-γ. Interestingly, the ratio of antigen-expanded CD4(+)IFN-γ(+)IL-17(+) lymphocytes, in peripheral blood and pleural fluid from TB patients, was correlated directly with clinical parameters associated with disease severity. Indeed, the highest proportion of CD4(+)IFN-γ(+)IL-17(+) cells was detected in Low Responder TB patients, individuals displaying severe pulmonary lesions, and longest length of disease evolution. Taken together, the present findings suggest that analysis of the expansion of CD4(+)IFN-γ(+)IL-17(+) T lymphocytes in peripheral blood of TB patients might be used as an indicator of the clinical outcome in active TB.