Search results for "PHAGOCYTOSIS"
showing 10 items of 169 documents
The Role of Spatial Exploration and Territoriality in Establishing Gilthead Seabream (Sparus aurata) Hierarchies, and Their Effects upon Underlying S…
2023
Territoriality, spatial exploration and social hierarchy are strictly related behaviors in gregarious fishes, and are often under-appreciated in farms where the individuals are confined within crowded spaces. In this study, we investigated the role of spatial exploration, elucidating the importance of time upon forming the social organization, and the role of the territoriality in gilthead seabream (Sparus aurata), using two experimental approaches. In the first approach, three fish were placed sequentially in the aquarium with an interval of two days (sequential model), while in the second (simultaneous model), two fish were simultaneously placed in an aquarium divided by a barrier which w…
Development and validation of new methods for the study of oxidative stress by Imaging Flow Cytometry
2017
El estrés oxidativo se origina debido a un desequilibrio entre la producción de especies reactivas de oxígeno (ROS) y los mecanismos celulares antioxidantes. Este desequilibrio en el estado normal redox puede causar efectos tóxicos a través de la producción de radicales libres y peróxidos, que dañan a componentes esenciales de la célula, como proteínas, lípidos y ADN. Actualmente se cree que el estrés oxidativo está relacionado con los mecanismos en un gran número de enfermedades degenerativas y cáncer, y también se le atribuye un papel importante en el proceso de envejecimiento. En algunos casos, la producción de especies reactivas de oxígeno (ROS) no es un fenómeno indeseable sino que for…
The Metabolic Sensor GPR43 Receptor Plays a Role in the Control of Klebsiella pneumoniae Infection in the Lung
2018
Pneumonia is one of the leading causes of death and mortality worldwide. The inflammatory responses that follow respiratory infections are protective leading to pathogen clearance but can also be deleterious if unregulated. The microbiota is known to be an important protective barrier against infections, mediating both direct inhibitory effects against the potential pathogen and also regulating the immune responses contributing to a proper clearance of the pathogen and return to homeostasis. GPR43 is one receptor for acetate, a microbiota metabolite shown to induce and to regulate important immune functions. Here, we addressed the role of GPR43 signaling during pulmonary bacterial infection…
Mycobacterium tuberculosis Drives Expansion of Low-Density Neutrophils Equipped With Regulatory Activities
2019
In human tuberculosis (TB) neutrophils represent the most commonly infected phagocyte but their role in protection and pathology is highly contradictory. Moreover, a subset of low-density neutrophils (LDNs) has been identified in TB, but their functions remain unclear. Here, we have analyzed total neutrophils and their low-density and normal-density (NDNs) subsets in patients with active TB disease, in terms of frequency, phenotype, functional features, and gene expression signature. Full-blood counts from Healthy Donors (H.D.), Latent TB infected, active TB, and cured TB patients were performed. Frequency, phenotype, burst activity, and suppressor T cell activity of the two different subse…
Neutrophils: Between host defence, immune modulation, and tissue injury.
2015
Neutrophils, the most abundant human immune cells, are rapidly recruited to sites of infection, where they fulfill their life-saving antimicrobial functions. While traditionally regarded as short-lived phagocytes, recent findings on long-term survival, neutrophil extracellular trap (NET) formation, heterogeneity and plasticity, suppressive functions, and tissue injury have expanded our understanding of their diverse role in infection and inflammation. This review summarises our current understanding of neutrophils in host-pathogen interactions and disease involvement, illustrating the versatility and plasticity of the neutrophil, moving between host defence, immune modulation, and tissue da…
CD11b Regulates Fungal Outgrowth but Not Neutrophil Recruitment in a Mouse Model of Invasive Pulmonary Aspergillosis
2019
Abstract Background and Aims: In immunosuppressed individuals Aspergillus (A.) fumigatus is a frequent cause of invasive pulmonary aspergillosis (IPA) which is highly associated with relevant morbidity and mortality. Moreover, it often occurs in patients suffering from leukocyte-adhesion deficiency type 1 (LAD1) which is triggered by a functional loss of CD18 in ß2 integrin receptors as these receptors consist of an alpha subunit (CD11a-CD11d) and CD18 as the common beta subunit. ß2 integrin receptors are differentially expressed by leukocytes, and are required for cell-cell interaction, transendothelial migration, uptake of opsonized pathogens, and cell signaling processes. Here, we asked …
Apoptotic-like Leishmania exploit the host´s autophagy machinery to reduce T-cell-mediated parasite elimination
2015
Apoptosis is a well-defined cellular process in which a cell dies, characterized by cell shrinkage and DNA fragmentation. In parasites like Leishmania, the process of apoptosis-like cell death has been described. Moreover upon infection, the apoptotic-like population is essential for disease development, in part by silencing host phagocytes. Nevertheless, the exact mechanism of how apoptosis in unicellular organisms may support infectivity remains unclear. Therefore we investigated the fate of apoptotic-like Leishmania parasites in human host macrophages. Our data showed--in contrast to viable parasites--that apoptotic-like parasites enter an LC3(+), autophagy-like compartment. The compartm…
Uptake of Bead-Adsorbed Versus Soluble Antigen by Bone Marrow Derived Dendritic Cells Triggers Their Activation and Increases Their Antigen Presentat…
1995
The property to internalize particles has for long time been ascribed primarily to macrophages. DC in contrast were considered generally as phagocytosis negative. Fully mature DC which can be isolated from various tissues of the body do indeed not take up particulate material; however immature DC which arise in differentiating bone marrow cultures do exhibit phagocytic capacity1. Consistent with their immature phenotype epidermal Langerhans cells were also described to possess phagocytic potential2.
Granulocyte Activity Is Enhanced by Culture Supernatants of Mononuclear Leukocytes Incubated with Tetrachlorodecaoxide
1995
Granulocytes (polymorphonuclear leukocytes, PMNs) and monocytes/ macrophages are important in wound healing. Within the first few hours PMNs and monocytes begin to infiltrate sites of injury. The major function of PMNs is to kill microbes and phagocytose cellular debris so that healing can proceed [1]. Monocytes/macrophages invading the wound are also active in phagocytosis. In addition they release a number of cytokines including growth factors, interleukin-8 (IL-8), and tumor necrosis factor (TNF-α) needed for new tissue formation and shown to stimulate PMNs [1–3].
Seabream (Sparus aurata) long-term dominant-subordinate interplay affects phagocytosis by peritoneal cavity cells.
2012
Fish are sensitive to stressful conditions that affect their innate immune systems and increase their susceptibility to diseases. We examined the social stress of paired gilthead seabream (Sparus aurata). Social hierarchies (dominant/subordinate) were characterised by behavioural changes, such as “aggressiveness” and “feeding order”; hierarchical positions were established within an hour of exposure to social stress and remained unchanged for approximately 1 year. To characterise physiological stress, we measured blood plasma levels of cortisol, glucose, and lactate as well as osmolarity and observed that the levels of these stress markers were higher in subordinate individuals than in domi…