macrophages
Observation | Host-Microbe BiologyLaccase Affects the Rate of Cryptococcus neoformans Nonlytic Exocytosis from MacrophagesCryptococcus neoformans is a yeast that causes severe disease, primarily in immunosuppressed people. It has many attributes that allow it to survive and cause disease, such as a polysaccharide capsule and the dark pigment melanin produced by the laccase enzyme. Upon infection, the yeast is ingested by cells called macrophages, whose function is to kill them. Instead,...
Research Article | Host-Microbe BiologyStaphylococcus aureus ATP Synthase Promotes Biofilm Persistence by Influencing Innate ImmunityMedical device-associated biofilm infections are a therapeutic challenge based on their antibiotic tolerance and ability to evade immune-mediated clearance. The virulence determinants responsible for bacterial biofilm to induce a maladaptive immune response remain largely unknown. This study identified a critical role for S. aureus ATP synthase in influencing the host...
Research Article | Host-Microbe BiologyThree Related Enzymes in Candida albicans Achieve Arginine- and Agmatine-Dependent Metabolism That Is Essential for Growth and Fungal Virulence...We show that the C. albicans ureohydrolases arginase (Car1), agmatinase (Agt1), and guanidinobutyrase (Gbu1) can orchestrate an arginase-independent route for polyamine production and that this is important for C. albicans growth and survival in microenvironments of the mammalian host.
Research Article | Host-Microbe BiologyInhibition of Fatty Acid Oxidation Promotes Macrophage Control of Mycobacterium tuberculosisMycobacterium tuberculosis (Mtb) is the leading infectious disease killer worldwide. We discovered that intracellular Mtb fails to grow in macrophages in which fatty acid β-oxidation (FAO) is blocked. Macrophages treated with FAO inhibitors rapidly generate a burst of mitochondria-derived reactive oxygen species, which promotes NADPH oxidase recruitment and autophagy...
Research Article | Host-Microbe BiologyDectin-1 Stimulation of Hematopoietic Stem and Progenitor Cells Occurs In Vivo and Promotes Differentiation Toward Trained Macrophages via an Indirect Cell-Autonomous MechanismInvasive candidiasis is an increasingly frequent cause of serious and often fatal infections. Understanding host defense is essential to design novel therapeutic strategies to boost immune protection against Candida albicans. In this article, we delve into two new concepts that have arisen over the last years: (i) the delivery of myelopoiesis-inducing signals by...
Research Article | Host-Microbe BiologyEhrlichia chaffeensis Uses an Invasin To Suppress Reactive Oxygen Species Generation by Macrophages via CD147-Dependent Inhibition of Vav1 To Block Rac1 ActivationEhrlichia chaffeensis is an obligatory intracellular bacterium with the capability of causing an emerging infectious disease called human monocytic ehrlichiosis. E. chaffeensis preferentially infects monocytes and macrophages, professional phagocytes, equipped with an arsenal of antimicrobial mechanisms, including rapid reactive oxygen species (ROS)...
Research Article | Host-Microbe BiologySimian Immunodeficiency Virus-Infected Memory CD4+ T Cells Infiltrate to the Site of Infected Macrophages in the Neuroparenchyma of a Chronic Macaque Model of Neurological Complications of AIDSWhile the use of combination antiretroviral therapy effectively suppresses systemic viral replication in the body, neurocognitive disorders as a result of HIV infection of the central nervous system (CNS) remain a clinical problem. Therefore, the use of nonhuman primate models is necessary to study mechanisms of neuropathogenesis. The neurotropic, molecular clone SIVsm804E-CL757 (CL757) results in neuroAIDS in 50% of infected rhesus...
Research Article | Host-Microbe BiologyMetabolism of Gluconeogenic Substrates by an Intracellular Fungal Pathogen Circumvents Nutritional Limitations within MacrophagesHistoplasma is a primary human fungal pathogen that survives and proliferates within host immune cells, particularly within the macrophage phagosome compartment. The phagosome compartment is a nutrient-limited environment, requiring Histoplasma yeasts to be able to assimilate available carbon sources within the phagosome to meet their nutritional needs. In this study, we showed that Histoplasma yeasts do not...
Research Article | Host-Microbe BiologyA MicroRNA Network Controls Legionella pneumophila Replication in Human Macrophages via LGALS8 and MX1Cases of Legionella pneumophila pneumonia occur worldwide, with potentially fatal outcome. When causing human disease, Legionella injects a plethora of virulence factors to reprogram macrophages to circumvent immune defense and create a replication niche. By analyzing Legionella-induced changes in miRNA expression and genomewide chromatin...
Research Article | Host-Microbe BiologyNucleic Acid-Sensing Toll-Like Receptors Play a Dominant Role in Innate Immune Recognition of PneumococciThe pneumococcus is a bacterium that frequently causes infections in the lungs, ears, sinus cavities, and meninges. During these infections, body defenses are triggered by tissue-resident cells that use specialized receptors, such as Toll-like receptors (TLRs), to sense the presence of bacteria. We show here that pneumococci are predominantly detected by TLRs that are located inside intracellular vacuoles, including endosomes, where...