What is the common pathway of cellular innate immunity?
- physical and chemical barriers to infection
- cellular response to infection
- activation of the adaptive immune response
What happens after tissue damage?
bacteria and tissue damage cause resident sentinel cells to release chemoattractants and vasoactive factors that trigger a local increase in blood flow and capillary permeability, allowing influx of fluid and cells.
What is the inflammation role?
key for host defence, tissue repair and restoration of homeostasis
What causes acute inflammation?
allergic reaction, chemical irritants, infection, trauma injury, burns, frostbite
What does acute inflammation cause?
chronic inflammation
What does chronic inflammation cause?
cardiovascular disease, neurological disease, autoimmune disease, rheumatoid arthritis, cancer, cancer, lupus, fibromyalgia and chronic fatigue syndrome
what are the first cells to act in inflammation?
monocytes and macrophages
How do macrophages differentiate between self and nonself cells
the receptors recognize cell-surface carbohydrates of bacterial calls but not human ones
What are the names of the receptors macrophages express for microbes?
Pattern recognition receptors (PRRs)
Are these receptors less specific than those of adaptive immunity?
one receptor can bind to a large class of microbes instead of being specififc to individual microbes
What do PRRs bind to?
Pathogen associated molecular patterns (PAMP)
What is the likely pathway of a marophage receptor that recognizes components of a microbial surface?
microorganisms are bound on the surface of macrophage, they are internalized by receptor-mediated endocytosis and then fusion of the endosome with a lysosome forms phagolysosome.
Other than phagocytosis, what else can occur once a PRR binds to a PAMP
signal transduction cascade, which leads to changes in transcription in the cell, thus new proteins by translation, inflammatory cytokines
What are cytokines?
proteins that communicate between cells of the immune system
What are chemokines?
specific type of cytokine which induce cell movement and migration
What are endocrines?
cytokines that must pass within blood stream to reach target cell
What are paracrines?
cytokines that act on neighbouring cells (diffusion of a new nanometers)
What are autocrine?
cells that receives a signal from itself
What are cytokines produced by activated by macrophages?
IL-1B, TNF-a, IL-6, CXCL8 (IL-8), IL-12
What do IL-1B and TNF-a cytokines responsible for?
induce blood vessels to become more permeable enabling effector cells and fluid containing soluble effector molecules to enter the infected tissues.
What is IL-6 responsible for?
Induces fat and muscle cells to metabolize make heat and raise the temperature in the infected tissue
What is CXCL8 or IL-8 responsible for?
recruits neutrophils from the blood and guides them to infected tissues
What is IL-12 responsible for?
recruits and activated NK cells that in turn secrete cytokines that strengthen the macrophages response to infection
What is vasodilation?
vascular dilation increases blood flow and introduces gaps between the cells of the endothelium, allows more cells to get to the site
