Browsing by Author "Saraiva, Margarida"
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- CD5L is upregulated upon infection with Mycobacterium tuberculosis with no effect on disease progressionPublication . Cardoso, Marcos S.; Gonçalves, Rute; Oliveira, Liliana; Silvério, Diogo; Téllez, Erica; Paul, Tony; Sarrias, Maria Rosa; Carmo, Alexandre M.; Saraiva, MargaridaTuberculosis (TB) alone caused over a billion deaths in the last 200 years, making it one of the deadliest diseases to humankind. Understanding the immune mechanisms underlying protection or pathology in TB is key to uncover the much needed innovative approaches to tackle TB. The scavenger receptor cysteine-rich molecule CD5 antigen-like (CD5L) has been associated with TB, but whether and how CD5L shapes the immune response during the course of disease remains poorly understood. Here, we show an upregulation of CD5L in circulation and at the site of infection in C57BL/6 Mycobacterium tuberculosis-infected mice. To investigate the role of CD5L in TB, we studied the progression of M. tuberculosis aerosol infection in a recently described genetically engineered mouse model lacking CD5L. Despite the increase of CD5L during infection of wild-type mice, absence of CD5L did not impact bacterial burden, histopathology or survival of infected mice. Absence of CD5L associated with a modest increase in the numbers of CD4+ T cells and the expression of IFN-γ in the lungs of infected mice, with no major effect in overall immune cell dynamics. Collectively, this study confirms CD5L as a potential diagnostic biomarker to TB, showing no discernible impact on the outcome of the infection.
- Comprehensive assessment of environmental fungus-reactive T cells response in hypersensitivity pneumonitis patientsPublication . Santos, Rita F.; Coelho, Andreia L.; Rufo, João C.; Coelho, David; Gonçalves, Melany; Gonçalves, Samuel L.; Cunha, Cristina; Carvalho, Agostinho; Delgado, Luís; Morais, António; Saraiva, Margarida; Novais-Bastos, HélderHypersensitivity pneumonitis (HP) is an interstitial lung disease that results in parenchymal and small airways inflammation and culminates in breathlessness, negatively impacting patient’s quality of life and survival. HP is initiated by an exaggerated immune response triggered by the inhalation of a variety of environmental antigens. The identification of the triggering antigen is a cornerstone of the diagnostic algorithm, and importantly, exposure avoidance ameliorates the clinical outcomes. However, the inciting antigen is not identified in a large proportion of patients. A difficult to identify, but common inciting antigen, is exposure to household fungi.
- Decoding host-environment interactions in progressive pulmonary fibrosis: insights from hypersensitivity pneumonitisPublication . Meneses, Alexandra; Cardoso, Catarina G.; Coelho, David B.; Melo, Natália; Mota, Patrícia C.; Guimarães, Susana; Moura, Conceição S.; Carvalho, André; Sokhatska, Oksana; Beltrão, Marília; Delgado, Luís; Morais, António; Saraiva, Margarida; Bastos, Hélder N.; Santos, Rita F.Interstitial lung diseases (ILDs) comprise a heterogeneous group of parenchymal lung disorders characterized by diffuse infiltration of immune effector cells, fibroblasts, myofibroblasts, and extracellular matrix deposition at various pulmonary compartments. These conditions can progress to end-stage fibrosis, respiratory failure, and eventually, death. In 2020, we initiated the first national ILD registry and biobank under the FIBRALUNG project, which has enrolled over 950 cases to date, with over 40% of the cases being fibrotic ILDs. The most represented fibrotic ILD groups are Hypersensitivity Pneumonitis (HP) (46%), Idiopathic Pulmonary Fibrosis (IPF) (20%), and unclassifiable ILD (8%). HP is the leading cause of pulmonary fibrosis, nearly doubling the number of IPF cases, which contrasts with numbers from other countries. This underscores the importance of investigating non-IPF progressive pulmonary fibrosis within our setting. Longitudinal patient follow-up and biological sample collection were performed allowing patient stratification according to progression criteria. Our work so far has highlighted a potential role of CCL2-CCR2 axis in fibrotic HP disease progression. Elevated serum CCL2 strongly associated with disease progression and acute exacerbations, with baseline levels above 1080 pg/mL predicting oneyear progression/mortality. To complement these findings, we are conducting blood transcriptome analyses across different HP patient groups to identify progression-specific signatures. Simultaneously, lung microbiome profiling is underway to explore its role in fibrotic progression. These integrative approaches aim to uncover novel biomarkers and mechanistic pathways, paving the way for tailored therapeutic interventions.
- IL-10 and Cdc42 modulate astrocyte-mediated microglia activation in methamphetamine-induced neuroinflammationPublication . Silva, Ana Isabel; Socodato, Renato; Pinto, Carolina; Terceiro, Ana Filipa; Canedo, Teresa; Relvas, João Bettencourt; Saraiva, Margarida; Summavielle, TeresaMethamphetamine (Meth) use is known to induce complex neuroinflammatory responses, particularly involving astrocytes and microglia. Building upon our previous research, which demonstrated that Meth stimulates astrocytes to release tumor necrosis factor (TNF) and glutamate, leading to microglial activation, this study investigates the role of the anti-inflammatory cytokine interleukin-10 (IL-10) in this process. Our findings reveal that the presence of recombinant IL-10 (rIL-10) counteracts Meth-induced excessive glutamate release in astrocyte cultures, which significantly reduces microglial activation. This reduction is associated with the modulation of astrocytic intracellular calcium (Ca2+) dynamics, particularly by restricting the release of Ca2+ from the endoplasmic reticulum to the cytoplasm. Furthermore, we identify the small Rho GTPase Cdc42 as a crucial intermediary in the astrocyte-to-microglia communication pathway under Meth exposure. By employing a transgenic mouse model that overexpresses IL-10 (pMT-10), we also demonstrate in vivo that IL-10 prevents Meth-induced neuroinflammation. These findings not only enhance our understanding of Meth-related neuroinflammatory mechanisms, but also suggest IL-10 and Cdc42 as putative therapeutic targets for treating Meth-induced neuroinflammation.
- Uncovering the mechanisms of protection during mycobacterium tuberculosis infectionPublication . Queirós, Sofia; Silva, Marta L.; Fernandes, Ana I.; Medina-Lopes, Mónica; Saraiva, Margarida; Cardoso, Marcos SantosTuberculosis (TB) is one of the most devastating infectious diseases affecting humankind, having caused 1.25 million deaths in 2023. The identification of effective protective mechanisms in TB could critically contribute to the urgent need of new therapies to stop TB. It is known that genetically related Mycobacterium tuberculosis (Mtb) isolates shape the immune response and disease outcomes. Using the natural genetic diversity of Mtb as a tool to understand protection in TB, my project focuses on the slow progressing infection caused by Mtb isolates of lineage 6 (L6), in which we hypothesize that critical protective mechanisms operate. Analyses of in vitro (macrophages) and in vivo (mouse) infections were performed in susceptible C3HeB/FeJ or resistant C57BL/6 mice, to compare the immune response and outcome of infection caused by Mtb belonging to L6 or L4. Results: In vitro (macrophage) infections showed that both Mtb L6 and Mtb L4 isolates grow overtime, but Mtb L6 grows slower than Mtb L4. In vivo, we found that C57BL/6 mice infected with Mtb L6 offer a unique model of full protection. Strikingly, flow cytometry analysis revealed a faster recruitment of activated CD4+ T cells to the lungs in the Mtb L6-infected C57BL/6, which might suggest that protection may be achieved by this early T cells recruitment. Our results indicate that a slower growth of Mtb L6 in macrophages together with earlier T cell responses in the lung may underlie fully infection control. The ongoing RNA-sequencing analyses will highlight putative protective immune mechanisms operating in this model, of great interest to devise new strategies to control TB.
- Unveiling common molecular pathways linked to ILDs with progressive fibrosing phenotype: the role of MUC5BPublication . Santos, Rita F.; Gonçalves, Melany; Mota, Patrícia Caetano; Cardoso, Catarina Gouveia; Coelho, Andreia L.; Sokhatska, Oksana; Beltrão, Marília; Guimarães, Susana; Delgado, Luís; Soares, Miguel; Morais, António; Saraiva, Margarida; Bastos, Hélder NovaisProgressive fibrosing ILDs (PF-ILDs) comprise a heterogeneous group of lung disorders associated with high morbidity and mortality, that exhibit a continuous worsening phenotype despite standard treatment. Among PF-ILDs are pulmonary fibrosis (IPF) and fibrotic hypersensitivity pneumonitis (HP), involving complex interactions between host genetics and different environmental triggers, shaping the immune milieu that ultimately drives the fibrotic cascade in a susceptible patient. The MUC5B promoter variant rs35705950 is the common genetic variant associated with the greatest risk of developing IPF. As IPF and fibrotic HP present phenotypic resemblances, we aim to analyze the role of rs35705950 MUC5B single nucleotide polymorphism (SNP) in common molecular pathways linked to PF-ILDs. Herein, taking advantage of our extensive ILD patients’ cohort, we found that MUC5B rs35705950 GT and TT genotypes frequency was dramatically increased in IPF and fibrotic HP compared to healthy controls.