These include neutrophils, eosinophils, and basophils. - are the predominant phagocytes of the early inflammatory response, arriving 6 to 12 hours after the initial injury.
In addition, the inflammatory consequences of particle internalization vary remarkably. Phagocytosis mediated by the Fc receptor is strongly proinflammatory, complement receptor—mediated phagocytosis is noninflammatory, and the uptake of apoptotic cells is anti-inflammatory [ 1 ].
Eosinophils serve as the body's primary defense against parasites. T lymphocytes and B lymphocytes are involved in acquired immunity. Neutrophils are the predominant phagocytes in the early inflammatory site. 40. Which chemical mediators induce pain during an inflammatory response?
- A phagocyte produced in bone marrow that migrates into tissues and is transformed into a macrophage. Macrophages are important in cellular initiation of the inflammatory response. They are the predominant phagocytic cell in the late inflammatory response, responsive to cytokines, and promote wound healing.
C. Chronic inflammation is characterized by a dense infiltrate of lymphocytes and macrophages. Giant cells are multinucleated cells that are formed by fused macrophages during granuloma formation. Chronic inflammation often results in pus formation, purulent discharge, and incomplete wound healing.
Infection with a virus can lead to the start of the inflammatory process, but is not the specific activation factor. Mast cells release the contents of their granules to initiate synthesis of other mediators of inflammation among other actions. Macrophages are one cell type involved in phagocytosis. 8.
The coagulation (clotting) system is a group of plasma proteins that form a fibrinous meshwork at an injured or inflamed site. This protein system (1) prevents the spread of infection to adjacent tissues, (2) traps microorganisms and foreign bodies at the site of inflammation for removal by infiltrating cells (e.g., neutrophils and macrophages), ...
The biologic activity of platelet-activating factor is virtually identical to that of leukotrienes; namely, it causes endothelial cell retraction to increase vascular permeability, leukocyte adhesion to endothelial cells, and platelet activation.
The complement cascade can be activated by at least three different means, and its products have four functions: (1) anaphylatoxic activity, resulting in mast cell degranulation, (2) leukocyte chemotaxis, (3) opsonization, and (4) cell lysis.
Vasodilation (increased size of the blood vessels) causes slower blood velocity and increases blood flow to the injured site. Endothelial cell contraction (not expansion) leads to increased capillary permeability.
If the epithelial barrier is damaged, then a highly efficient local and systemic response (inflammation) is mobilized to limit the extent of damage, to protect against infection, and to initiate the repair of damaged tissue. The response to a specific offending agent is the function of the adaptive immune response.
Endothelial cell contraction . ANS: A. The increased blood flow as a result of vasodilation and increasing concentration of red cells at the site of inflammation cause locally increased warmth and redness. The other options do not accurately identify the process that results in inflammatory redness and heat.
The coagulation (clotting) system is a group of plasma proteins that form a fibrinous meshwork at an injured or inflamed site. This protein system (1) prevents the spread of infection to adjacent tissues, (2) traps microorganisms and foreign bodies at the site of inflammation for removal by infiltrating cells (e.g., neutrophils and macrophages), ...
The complement cascade can be activated by at least three different means, and its products have four functions: (1) anaphylatoxic activity, resulting in mast cell degranulation, (2) leukocyte chemotaxis, (3) opsonization, and (4) cell lysis.
Phagocytosis is an ancient adaptation. In primitive organisms, it is primarily used for the acquisition of nutrients [ 4 ], whereas, in higher organisms, it occurs in specialized cells (e.g., macrophages, DCs, and neutrophils) and is required for a wide variety of specialized biologic events.
Macrophages are a cornerstone of the innate immune system. They detect infectious organisms via a plethora of receptors, phagocytose them, and orchestrate an appropriate host response. Phagocytosis is extraordinarily complex: numerous receptors stimulate particle internalization, the cytoskeletal elements mediating internalization differ by ...
Pathogen-associated motifs include mannans in the yeast cell wall, formylated peptides in bacteria, and lipopolysaccharides (LPSs) and lipoteichoic acids on the surface of gram-negative and gram-positive bacteria. The recognition mechanisms leading to phagocytosis can be pattern based, humoral, or a combination.
Amphiphysin IIm binds to dynamin 2, and the role of these 2 proteins in regulating phagocytosis was probed with dominant negative mutants [ 16, 18 ]. Both mutants inhibited phagocytosis and appeared to do so by preventing the insertion of membrane into the forming pseudopod; actin polymerization was unaffected.
The phagolysosome is an acidic, hydrolytic compartment in which the pathogen is killed and digested in preparation for antigen presentation. This general model is reasonably useful in facilitating the dissection of phagocytosis.
This process, called antigen presentation, results in specific T cell activation and is the interface between the innate and adaptive immune systems.
Innate immunity is the first line of defense against microbial infection. It is mediated primarily by white blood cells, such as macrophages, neutrophils, and dendritic cells (DCs), although I will focus only on macrophages.