Bruno Marcel Silva de Melo (original) (raw)

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Papers by Bruno Marcel Silva de Melo

Nature immunology, Feb 14, 2024

Journal of Investigative Dermatology

ABSTRACTCD4+ T cells are key components of the immune response during lung infections and can med... more ABSTRACTCD4+ T cells are key components of the immune response during lung infections and can mediate protection against tuberculosis (TB) or influenza. However, CD4+ T cells can also promote lung pathology during these infections, making it unclear how these cells control such discrepant effects. Using mouse models of hypervirulent TB and influenza, we observed that exaggerated accumulation of parenchymal CD4+ T cells promotes lung damage. Low numbers of lung CD4+ T cells, in contrast, are sufficient to protect against hypervirulent TB. In both situations, lung CD4+ T cell accumulation is mediated by CD4+ T cell-specific expression of the extracellular ATP (eATP) receptor P2RX7. P2RX7 upregulation in lung CD4+ T cells promotes expression of the chemokine receptor CXCR3 and favors in situ proliferation. Our findings suggest that direct sensing of lung eATP by CD4+ T cells is critical to induce tissue CD4+ T cell accumulation and pathology during lung infections.GRAPHICAL ABSTRACT

Journal of Investigative Dermatology, 2021

In their report, Chen et al. provide new insights into psoriasis pathogenesis, showing that neutr... more In their report, Chen et al. provide new insights into psoriasis pathogenesis, showing that neutrophil infiltration of skin lesions increases vascular endothelial cell (VEC) activation, leading to cutaneous vasodilation and enhanced vascular permeability. In patients with psoriasis, neutrophil-derived matrix metalloproteinase 9 (MMP-9) plays a pivotal role in VEC barrier dysfunction, via extracellular signal-regulated kinase-1/2 and p38 pathways. Pharmacologic inhibition of MMP-9 in two different models confers reduced cutaneous vasodilation, vascular permeability, and inflammation, suggesting MMP-9 as a target in psoriasis pathogenesis.

Revista Verde de Agroecologia e Desenvolvimento Sustentável, 2013

The rampant use of pesticides has caused many environmental problems such as contamination of soi... more The rampant use of pesticides has caused many environmental problems such as contamination of soil, water, ecosystems, in addition to affecting the health of the field worker and consumer. In the search for alternative pest control in stored seeds, many researchers have been devoted to studying extracts and vegetable oils, capable of controlling the pests. The objective of this work was to control the maize weevil (Sitophilus zeamais) with hydroalcoholic extracts of Momordica charantia L. and C. baccatum L. in different doses. Treatment was performed in the grain extracts of M. charantia (leaves, stems and fruits) and C. baccatum (fruit) and these seeds were stored in containers with a capacity of 250g pet, for a period of 120 days, every 30 days where there were the analysis of the rate of infestation of seeds. The extract of M. charantia extract was superior to C. baccatum in controlling the infestation of S. zeamais during 120 days of storage in which the extract of M. charantia ...

Frontiers in Cellular and Infection Microbiology, 2021

The risk of developing severe forms of tuberculosis has increased by the acquired immunodeficienc... more The risk of developing severe forms of tuberculosis has increased by the acquired immunodeficiency syndrome (AIDS) epidemic, lack of effective drugs to eliminate latent infection and the emergence of drug-resistant mycobacterial strains. Excessive inflammatory response and tissue damage associated with severe tuberculosis contribute to poor outcome of the disease. Our previous studies using mice deficient in the ATP-gated ionotropic P2X7 receptor suggested this molecule as a promising target for host-directed therapy in severe pulmonary tuberculosis. In this study, we assessed the effects of P2X7 pharmacological blockade on disease severity. First, we observed an increase inP2RX7gene expression in the peripheral blood of tuberculosis patients compared to healthy donors. Lung leukocytes of mice infected with hypervirulent mycobacteria also showed increased expression of the P2X7 receptor. P2X7 blockade in mice with advanced tuberculosis recapitulated in many aspects the disease in P2...

Science Immunology, 2021

IL-12 protects from psoriasiform inflammation via interfollicular keratinocytes by promoting skin... more IL-12 protects from psoriasiform inflammation via interfollicular keratinocytes by promoting skin homeostasis.

COVID-19 patients may exhibit neuropsychiatric and neurological symptoms. We found that anxiety a... more COVID-19 patients may exhibit neuropsychiatric and neurological symptoms. We found that anxiety and cognitive impairment are manifested by 28-56% of SARS-CoV-2-infected individuals with mild respiratory symptoms and are associated with altered cerebral cortical thickness. Using an independent cohort, we found histopathological signs of brain damage in 25% of individuals who died of COVID-19. All of the affected brain tissues exhibited foci of SARS-CoV-2 infection and replication, particularly in astrocytes. Infection of neural stem cell-derived astrocytes changed energy metabolism, altered key proteins and metabolites used to fuel neurons and for biogenesis of neurotransmitters, and elicited a secretory phenotype that reduces neuronal viability. Our data support the model where SARS-CoV-2 reaches the brain, infects astrocytes and triggers neuropathological changes that contribute to the structural and functional alterations in the brain of COVID-19 patients.