Search results for "Bacterium"
showing 10 items of 595 documents
Th0 to Th1 switch of CD4 T cell clones specific from the 16-kDa antigen of Mycobacterium tuberculosis after successful therapy: lack of involvement o…
2005
Abstract In this study, we have examined the influence of HLA-DR molecules and the structure of the epitope repertoire of the 16-kDa protein of Mycobacterium tuberculosis on the acquisition of the cytokine secretion pattern of CD4 T cell clones, obtained from tuberculous patients before and after anti-mycobacterial therapy. Our data indicate that TB patients have a predominant Th0 response against the 16-kDa protein and its epitopes and that healing, induced by anti-mycobacterial therapy, is associated with a shift toward a predominant Th1 phenotype. Moreover, both HLA-DR molecules restricting the clone specificity and the nature of the recognized epitope do not play any role in the generat…
Mycobacterium tuberculosis Immune Response in Patients With Immune-Mediated Inflammatory Disease
2021
Subjects with immune-mediated inflammatory diseases (IMID), such as rheumatoid arthritis (RA), have an intrinsic higher probability to develop active-tuberculosis (TB) compared to the general population. The risk ranges from 2.0 to 8.9 in RA patients not receiving therapies. According to the WHO, the RA prevalence varies between 0.3% and 1% and is more common in women and in developed countries. Therefore, the identification and treatment of TB infection (TBI) in this fragile population is important to propose the TB preventive therapy. We aimed to study the M. tuberculosis (Mtb) specific T-cell response to find immune biomarkers of Mtb burden or Mtb clearance in patients with different TB …
Damping excessive inflammation and tissue damage in Mycobacterium tuberculosis infection by Toll IL-1 receptor 8/single Ig IL-1-related receptor, a n…
2007
Abstract Toll IL-1R 8/single Ig IL-1-related receptor (TIR8/SIGIRR) is a member of the IL-1R family, expressed by epithelial tissues and immature dendritic cells, and is regarded as a negative regulator of TLR/IL-1R signaling. Tir8-deficient mice were rapidly killed by intranasal administration of low doses of Mycobacterium tuberculosis, despite controlling efficiently the number of viable bacilli in different organs. Tir8−/−-infected mice showed an increased number of neutrophils and macrophages in the lungs; however, mycobacteria-specific CD4 and CD8 T cells were similar in Tir8−/− and Tir8+/+ mice. Exaggerated mortality of Tir8−/− mice was due to massive liver necrosis and was accompanie…
Biology of gama delta T Cells in Tuberculosis and Malaria
2002
Tuberculosis and malaria remain the leading causes of mortality among human infectious diseases in the world. It is estimated that 3 to 5 million people die from tuberculosis and malaria each year. Although it is traditionally believed that CD4 and CD8 alphabeta T lymphocytes are mandatory for protective immune responses against Mycobacterium tuberculosis and Plasmodium falciparum (the ethiologic agents of tuberculosis and the most severe form of malaria, respectively), there is still incomplete understanding of the mechanisms of immune protection and of the causes of its failure in the affected patients. Several studies in humans and animal models have suggested that Vgamma9/Vdelta2 T cell…
Mycobacterium tuberculosis secretory proteins downregulate T cell activation by interfering with proximal and downstream T cell signalling events
2015
Background Mycobacterium tuberculosis (M. tuberculosis) modulates host immune response, mainly T cell responses for its own survival leading to disease or latent infection. The molecules and mechanisms utilized to accomplish immune subversion by M. tuberculosis are not fully understood. Understanding the molecular mechanism of T cell response to M. tuberculosis is important for development of efficacious vaccine against TB. Methods Here, we investigated effect of M. tuberculosis antigens Ag85A and ESAT-6 on T cell signalling events in CD3/CD28 induced Peripheral blood mononuclear cells (PBMCs) of PPD+ve healthy individuals and pulmonary TB patients. We studied CD3 induced intracellular calc…
A helicopter perspective on TB biomarkers: pathway and process based analysis of gene expression data provides new insight into TB pathogenesis.
2013
Biomarker host genetic signatures are considered key tools for improved early diagnosis of tuberculosis (TB) disease (development). The analysis of gene expression changes based on a limited number of genes or single study designs, however, may not be sufficient for the identification of universal diagnostic biomarker profiles. Here we propose that biological pathway and process based analyses from multiple data sets may be more relevant for identification of key pathways in TB pathogenesis, and may reveal novel candidate diagnostic TB biomarkers. A number of independent genome-wide gene expression studies have recently been performed to study expression of biomarkers for TB disease. We hav…
IL-4 depletion enhances host resistance and passive IgA protection against tuberculosis infection in BALB/c mice.
2007
The influence of Th2 cytokines in tuberculosis has been a matter of dispute. Here we report that IL-4 has a profound regulatory effect on the infection of BALB/c mice with Mycobacterium tuberculosis. Depletion of IL-4 with a neutralizing mAb caused only evanescent reduction of lung infection, but when combined with i.n. inoculations of IgA anti-mycobacterial alpha-crystallin mAb and mouse rIFN-gamma, we observed a 40-fold reduction of the bacterial counts in the lungs at 3 wks following i.n. infection (p<0.001). In genetically deficient IL-4-/- BALB/c mice, infection in both lung and spleen was substantially reduced for up to 8 wks without further treatment. Reconstitution of IL-4-/- mice w…
Tuberculosis en el Departamento de Salud Valencia-Doctor Peset. Aportación de los métodos de microbiología molecular
2018
La tuberculosis (TB) se mantiene como problema importante de salud pública a pesar de la disminución progresiva de su incidencia en nuestro medio. Los programas de control deben incluir objetivos de mejora en detección precoz de pacientes bacilíferos y la eficacia y rapidez de los métodos de rutina microbiológica para identificación y sensibilidad de Mycobacterium tuberculosis complex, detectando cepas multirresistentes (MDR-TB) de forma rápida y sencilla. En este trabajo se describe el modelo de funcionamiento del Servicio de Microbiología en la detección y control de las TB del Departamento de Salud Valencia- Dr. Peset en los últimos once años, calculando la evolución de tasas de incidenc…
Understanding the dialog between the gut microbiota and the endosymbiont in the model system Blattella germanica
2020
Aquesta tesi doctoral forma part de la investigació sobre l’evolució de la simbiosi en insectes realitzada durant molts anys pel grup de Genètica Evolutiva de la Universitat de València. L’organisme model utilitzat en aquest estudi és la panerola alemanya, Blattella germanica, un insecte omnívor i cosmopolita. La panerola alemanya posseeix dos simbionts: un endosimbiont, Blattabacterium, i una microbiota intestinal complexa. La funció de l’endosimbiont ha estat proposada prèviament com a la producció de metabòlits essencials mitjançant el reciclatge del nitrogen a través de la via ureolítica. Aquesta panerola comparteix la font d’aliment i l’ambient amb els humans, cosa que podria explicar …
¿Pueden los probióticos modificar las complicaciones asociadas a la obesidad infantil?
2022
En los últimos años, la microbiota intestinal se ha convertido en una novedosa y prometedora diana terapéutica para el tratamiento de la obesidad y enfermedades asociadas. Nuestra cepa de estudio, Bifidobacterium pseudocatenulatum CECT 7765, ha demostrado en repetidos estudios con modelos animales de obesidad que mejora alteraciones metabólicas e inmunológicas y restaura el daño vascular. HIPÓTESIS Y OBJETIVOS Según nuestra hipótesis, los resultados obtenidos en modelos murinos podrían ser reproducibles en humanos con el consumo regular de B. pseudocatenulatum CECT 7765, junto con la adopción de hábitos de alimentación saludables. El presente estudio clínico tiene como objetivo evaluar los …