BIOL 1119 Lecture Notes - Lecture 25: Heparin, Fibroblast, Monocyte
24 Mar 2017
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Document Summary
Messengers that link the components of the immune system together. Che(cid:373)ical co(cid:373)(cid:373)u(cid:374)icatio(cid:374) (cid:374)etwork that allows differe(cid:374)t i(cid:373)(cid:373)u(cid:374)e syste(cid:373) cells to (cid:862)talk(cid:863) to one another. Secreted by leukocytes, other immune cells, endothelial cells and injured cells: paracrine messenger local effect, autocrine messenger self effect, hormone blood stream. Cytokines usually act in most cases over a short distance on neighboring cells or on the same cell that secrete them (paracrine) Act on broad range of target cells. Regulate inflammation and immune responses: many cytokines are redundant in their action, cytokines include interferons (anti-viral), interleukins (stimulate other wbc), chemotactic factors (attract wbcs like neutrophils) Cytokines which nonspecifically inhibit viral replication in hot cells. Interferons alert neighboring cells: by bonding to surface receptors on nearby cell: activate 2nd msg system that stimulates those cells to make various kinds of antiviral proteins. Activated complement brings about 4 methods of pathogen destruction: promotes phagocytosis, causes immune clearance, causes cytolysis, promotes inflammation.
