Master this deck with 20 terms through effective study methods.
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Mast cells are a type of immune cell found in connective tissues close to blood vessels and in subepithelial areas of the respiratory, genitourinary, and gastrointestinal tracts. They play a crucial role in allergic responses and inflammation.
Basophils are granulocytes present in low numbers in circulation, and their primary function is to release histamine and other mediators during allergic reactions and inflammation. They are produced from stem cells in the bone marrow.
Mast cells and basophils release their granules through mechanisms such as binding to anaphylatoxins (C3a, C5a), crosslinking of IgE bound to their surface receptors, and binding to lectins. This release leads to the production of various mediators.
The main mediators released by mast cells include histamine, cytokines, tumor necrosis factor (TNFα), and platelet-activating factor (PAF). These mediators are involved in vasodilation and increased vascular permeability.
Dendritic cells (DCs) are antigen-presenting cells that serve as the primary interface between the innate and adaptive immune systems. They recognize microbial antigens and present peptide antigens to T helper (CD4) cells using MHC molecules.
Acute phase proteins are a heterogeneous group of plasma proteins produced mainly in the liver in response to infection, trauma, or malignancy. They play a critical role in the innate immune response and help limit tissue damage.
Cytokines are small signaling molecules that mediate communication between cells in the immune system. They induce growth, chemotaxis, activation, and regulation of immune responses, and can be classified into interleukins, monokines, lymphokines, and chemokines.
MHC class I molecules (HLA A, B, C) are responsible for presenting peptide antigens to CD8+ T cells. They play a crucial role in the recognition of infected or cancerous cells by cytotoxic T lymphocytes.
Natural killer (NK) cells are large granular lymphocytes that primarily kill virus-infected and tumor cells. They use a variety of receptors to distinguish between healthy and infected cells, and they release cytotoxic granules to induce apoptosis in target cells.
NK cells recognize infected cells through killer activation receptors (KARs) and killer inhibitory receptors (KIRs). KIRs recognize MHC class I molecules, and when these are downregulated by viral infection, NK cells are activated to kill the infected cells.
Phagocytosis involves several stages: the movement of phagocytes towards microbes, attachment of the microbe to the phagocyte surface, endocytosis leading to phagosome formation, fusion of the phagosome with lysosomes, and ultimately the killing of the microbe.
Interleukins are a type of cytokine that play various roles in the immune response, including activating lymphocytes, inducing fever, and promoting phagocyte mobilization. Specific interleukins, such as IL-2 and IL-4, are critical for T cell growth and differentiation.
Toll-like receptors (TLRs) are a type of microbial recognition receptor that mediate the immune response by recognizing pathogen-associated molecular patterns (PAMPs). They play a key role in cytokine production and the induction of adaptive immune responses.
Complement receptors, such as CD35 (CR1), enhance phagocytosis by binding to complement-coated microbes. They facilitate the recognition and clearance of pathogens by immune cells.
Interferons (IFNs) are cytokines that protect against viral infections by inhibiting protein synthesis in infected cells and enhancing the immune response. Type I interferons (IFNα, IFNβ) are produced in response to viral infections, while Type II interferon (IFNγ) activates immune cells.
Macrophages are key players in the immune response, acting as phagocytes that engulf and destroy pathogens. They also produce cytokines that activate other immune cells and help coordinate the immune response.
CD14 is a receptor that binds lipopolysaccharides (LPS) from bacterial cell walls, facilitating the recognition of pathogens by immune cells. It plays a crucial role in the activation of macrophages and the induction of inflammatory responses.
The three main types of dendritic cells are Langerhans cells, interdigitating cells, and follicular dendritic cells. Each type has distinct locations and functions in the immune system, primarily in antigen presentation and T cell activation.
IL-10 is a cytokine produced by Th2 cells and macrophages that plays a role in regulating immune responses. It inhibits the production of pro-inflammatory cytokines and promotes the differentiation of Th2 cells, thus helping to control inflammation.
Scavenger receptors are a type of microbial recognition receptor that bind to bacterial and yeast cell wall components. They facilitate the phagocytosis of pathogens and play a role in the induction of adaptive immune responses.