Polimorfismo gênico de receptores TLRs e citocinas: papel na resposta imune em pacientes com tuberculose pulmonar / Genomic polymorphism of TLR s and cytokine receptors: role in immune response in patients with pulmonary tuberculosis

It is estimated that one-third of the total world population is latently infected with M. tuberculosis and only 5-10% of the infected individuals will develop active TB disease during their life-time. The reason why some infected individuals develop active disease, while others do not is not yet entirely understood. Given the central role of TLR-2 in the incitement of inflammation, polymorphisms in its gene might be involved in both infectious and inflammatory diseases. The aim of this study was to evaluate the influence of TLR2 - 16934A/T and GT repeat polymorphisms on the immune response of PTB patients undergoing anti-TB treatment at different time points of anti-tuberculosis treatment: T1 (beginning), T2 (3 months) and T3 (end). For this we genotyped TLR2 -16934 and (GT)n repeats polymorphisms and evaluated the immune response of pulmonary tuberculosis patients during the time of anti-tuberculosis treatment. The present study suggests that TLR2 - 16934A/T and GT repeats polymorphisms can influence differential TLR-2, NF-κB and cytokine levels during anti-TB treatment. We also suggest that PTB patients with TLR2 - 16934 AA genotype may have a worst outcome of the disease, since they have a lower IFN-γ, cytokine essential to initiate the protective immunity to active TB. This association could not be made in our study due to the low number of patients evaluated. Since TLR-2 play a major role in initiating immune response against M...

Analysis of the expression of toll-like receptors 2 and 4 and cytokine production during experimental Leishmania chagasi infection

Toll-like receptors (TLRs) recognise pathogen-derived molecules and influence immunity to control parasite infections. This study aimed to evaluate the mRNA expression of TLRs 2 and 4, the expression and production of the cytokines interleukin (IL)-12, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-17, IL-10 and transforming growth factor (TGF)-β and the production of nitric oxide (NO) in the spleen of mice infected with Leishmania chagasi. It also aimed to evaluate any correlations between mRNA expression TLR2 and 4 and cytokines and NO production. Infection resulted in increased TLR2-4, IL-17, TNF-α and TGF-β mRNA expression during early infection, with decreased expression during late infection correlating with parasite load. IFN-γ and IL-12 mRNA expression decreased at the peak of parasitism. IL-10 mRNA expression increased throughout the entire time period analysed. Although TGF-β, TNF-α and IL-17 were highly produced during the initial phase of infection, IFN-γ and IL-12 exhibited high production during the final phase of infection. IL-10 and NO showed increased production throughout the evaluated time period. In the acute phase of infection, there was a positive correlation between TLR2-4, TNF-α, IL-17, NO, IL-10 and TGF-β expression and parasite load. During the chronic phase of infection, there was a positive correlation between TLR2-4, TNF-α, IL-17 and TGF-β expression and parasite load. Our data suggest that infection by L. chagasi resulted in modulation of TLRs 2 and 4 and cytokines.

Citocinas e proteínas de fase aguda do soro como marcadores de regressão da resposta inflamatória ao tratamento da tuberculose pulmonar / Cytokines and acute phase serum proteins as markers of inflammatory regression during the treatment of pulmonary tuberculosis

OBJETIVO: Analisar o padrão de citocinas pró- e antiinflamatórias e da resposta de fase aguda (RFA) como marcadores de resposta ao tratamento da tuberculose pulmonar. MÉTODOS: Determinação dos níveis de interferon-gama (IFN-γ), tumor necrosis factor-alpha (TNF-α, fator de necrose tumoral-alfa), interleucina-10 (IL-10) e transforming growth factor-beta (TGF-β, fator transformador de crescimento-beta), pelo método ELISA, em sobrenadante de cultura de células mononucleares do sangue periférico e monócitos, assim como dos níveis de proteínas totais, albumina, globulinas, alfa-1-glicoproteína ácida (AGA), proteína C reativa (PCR) e velocidade de hemossedimentação (VHS) em 28 doentes com tuberculose pulmonar, em três tempos: antes (T0), aos três meses (T3) e aos seis meses (T6) de tratamento, em relação aos controles saudáveis, em um único tempo. RESULTADOS: Os pacientes apresentaram valores maiores de citocinas e RFA que os controles em T0, com diminuição em T3 e diminuição (TNF-α, IL-10, TGF-β, AGA e VHS) ou normalização (IFN-γ e PCR) em T6. CONCLUSÕES: PCR, AGA e VHS são possíveis marcadores para auxiliar no diagnóstico de tuberculose pulmonar e na indicação de tratamento de indivíduos com baciloscopia negativa; PCR (T0 > T3 > T6 = referência) pode também ser marcador de resposta ao tratamento. Antes do tratamento, o perfil Th0 (IFN-γ, IL-10, TNF-α e TGF-β), indutor de e protetor contra inflamação, prevaleceu nos pacientes; em T6, prevaleceu o perfil Th2 (IL-10, TNF-α e TGF-β), protetor contra efeito nocivo pró-inflamatório do TNF-α ainda presente. O comportamento do IFN-γ (T0 > T3 > T6 = controle) sugere sua utilização como marcador de resposta ao tratamento.

OBJECTIVE: To evaluate the pattern of pro-inflammatory cytokines, anti-inflammatory cytokines and the acute phase response (APR) as markers of the response to treatment of pulmonary tuberculosis. METHODS: Twenty-eight patients with pulmonary tuberculosis were evaluated at three time points: pretreatment (T0), treatment month 3 (T3) and treatment month 6 (T6). Levels of interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), interleukine-10 (IL-10) and transforming growth factor-beta (TGF-β) were determined using ELISA in the supernatant of peripheral blood mononuclear cell and monocyte culture. Levels of total protein, albumin, globulins, C-reactive protein (CRP), alpha-1-acid glycoprotein (AAG) and erythrocyte sedimentation rate (ESR) were also determined. All of these parameters were also evaluated, only once, in a group of healthy controls. RESULTS: In relation to controls, patients presented cytokine levels and APR that were higher at T0, lower at T3 and either lower (TNF-α, IL-10, TGF-β, AAG and ESR) or normal (IFN-γ and CRP) at T6. CONCLUSIONS: For individuals with negative smear sputum microscopy, CRP, AAG and ESR are potential markers of pulmonary tuberculosis and of the need for treatment; CRP (T0 > T3 > T6 = reference) can also be a marker of treatment response. In the patients, the Th0 profile (IFN-γ, IL-10, TNF-α and TGF-β), inducer of and protector against inflammation, predominated at T0, whereas the Th2 profile (IL-10, TNF-α and TGF-β), protecting against the harmful pro-inflammatory effect of the remaining TNF-α, predominated at T6. The behavior of IFN-γ (T0 > T3 > T6 = controls) suggests its use as a marker of treatment response.

Definition of a diagnostic routine in individuals with inconclusive serology for chagas disease

Despite the existence of highly sensitive tests, inconclusive serological results are frequent in chronic chagasic infection. This study aimed to define a diagnostic conduct for 30 individuals with inconclusive serology (G3) for chagasic infection assisted at the Outpatient Unit for Infectious and Parasitic Diseases of the Botucatu School of Medicine. Twenty-one individuals with negative serology (G1) and 33 with positive serology (G2) were also studied. Serological methods ELISA, HAI, IFI and immunoblotting TESA-cruzi were used for G1, G2 and G3, and parasitological methods xenodiagnosis, hemoculture and PCR-LIT were used for G2 and G3 individuals. ELISA, HAI and IFI were performed in 5 different blood samples in G2 and G3. TESA-cruzi was carried out only once in G1, G2 and G3 and, since it is the most sensitive, it was utilized as standard. In G3, positivity for ELISA reached 86 percent in the fifth blood sample; the ELISA+HAI+IFI combination showed a maximum of 44.8 percent in the second sample; and TESA-cruzi, 76 percent in one single sample. Xenodiagnosis positivity was 9.4 percent; hemoculture showed 15.2 percent; and PCR-LIT exhibited 22 percent positivity in G2. Nevertheless, in G3, positivity percentage was 3.4 percent for xenodiagnosis, 6.7 percent for PCR-LIT, and no positive result was found for hemoculture. In G3, PCR-LIT resolved one case which was still inconclusive according to serology tests. In order to define inconclusive diagnoses, the results suggest the combined use of ELISA+HAI+IFI in 2 blood samples, decreasing the occurrence of false positive/negative results. If results remain inconclusive, the performance of TESA-cruzi and PCR-LIT, if necessary, is recommended.

Detection of enterotoxins genes in coagulase-negative staphylococci isolated from foods

A intoxicação alimentar estafilocócica ocorre devido à ingestão de alimentos contaminados com enterotoxinas. Essa contaminação tem sido oriunda, principalmente, da manipulação humana, ou de matérias-primas procedentes de animais portadores. Embora Staphylococcus aureus coagulase positiva, seja o principal agente de intoxicação alimentar, alguns pesquisadores enfatizam que os estafilococos coagulase-negativa (ECN) podem produzir as enterotoxinas estafilocócicas, podendo contribuir para a intoxicação alimentar. Este estudo teve como objetivos isolar os ECN de alimentos e verificar a capacidade enterotoxigênica dessas linhagens. Foram estudadas 88 amostras de alimentos, sendo que 22,7 por cento foram positivas para ECN com crescimento entre 102 e 106 UFC/g or mL. A espécie predominante dentre as linhagens isoladas foi S. epidermidis (40 por cento), seguido por S. warneri (20 por cento), S. xylosus (20 por cento), S. saccharolyticus (15 por cento) e S. hominis (5 por cento). Entre as linhagens isoladas, quatro apresentaram genes para produção de enterotoxinas pelo método de Reação da Polimerase em Cadeia (PCR), com predominância do gene sea. Não se detectou a produção de enterotoxina pelo método de aglutinação em látex (RPLA). Através dos resultados obtidos, observou-se que os ECN isolados de alimentos não devem ser ignorados quanto à sua capacidade toxigênica, necessitando de maior estudo e atenção para melhor caracterização desse grupo de microrganismos em alimentos.