Ch.16 Innate Immunity Part 2 Flashcards
what are some inflammation responses?
Redness
pain
heat
swelling
may or may not have a loss of function
what are some inflammation responses functions?
(a) destroy/remove agent;
(b) confine agent to local area;
(c) repair/replace damaged tissue
what happens during early stage of inflammation ?
Cytokine release – TNF-tumor necrosis factor –> induces formation of
acute-phase proteins
what are the stages of inflammation?
vasodilation
phagocyte migration
phagocytosis
repair
what does vasodilation do?
increases blood flow in the area (redness & heat)
what is vasodilation triggered by?
chemicals
histamine
kinins
what does increased permeability do?
permits entry of blood cells into the site (edema, swelling)
what is increased permeability permits entry of blood cells into the site (edema, swelling) due to?
kinins
leukotrienes (mast cells)
steps to the inflammatory response
- chemicals such as histamine kinins, prostaglandin leukotrienes, and cytokines are released by damaged cells
- Blood clot forms
- Abcess starts to form
- margination- phagocytes
stick to blood vessel walls - Diapedisis-phagocytes squeeze between cells. exiting blood vessel
- Phagocytosis of invading bacteria occurs
- phagocytosis removes microbes, and damaged tissue; pus formation
- tissue repair; replacements of dead, damaged tissues
in response to cytokines, what does it cause?
cause phagocytes to stick to blood vessel walls margination
what happens during diapedesis?
phagocytes squeeze between cells. exiting blood vessel
what does the hypothalamus do?
body’s thermostat
regulates body temp
what causes fevers?
pyrogens
what are exogenous pyrogens?
outside the body (bacteria viruses, others)
what are endogenous pyrogens (interleukin-1)?
act on the hypothalamus raising the temperature set point
what does elevated temperature cause?
slow pathogen growth
increases T cell activity
lowers the concentration of available iron
what does the complement cascade rely on?
on soluble protein factors in the blood to attack bacterial pathogens
define classical pathway
C3 is activated by contact between complement and pathogen via antibodies
define alternate pathway
C3 is activated by contact between complement & pathogen via surface glycolipid complexes
define lectin pathway
C3 is activated by contact between lectin & pathogen via surface-specific carbohydrates
ex: mannose
what are the effects of complement?
opsonization
inflammation
cytolysis
how does complement affect opsonization?
activated C3b proteins bind microbe;
phagocyte binds to C3b-> enhances phagocytosis
how does complement affect inflammation?
C3a & C5a bind mast cells causing the release of histamine, kinins
C5a also acts as a chemoattractant for phagocytes
how does complement affect cytolysis?
C3b proteins split C5 -> C5a + C5b
C5b promotes the formation of a complete protein complex that inserts into the plasma
form membrane attack complex MAC
channels form in the microbe causing lysis
what interferons?
cytokines that interfere with viral replication
how are interferons produced?
in response to infection
what kind of action is interferons?
is host specific
what are type 1 interferons?
high antiviral potency
bind receptors on uninfected host cell
renders them resistant to viral infection
what are type 2 interferons?
activates neutrophils and macrophages;
increases MHC antigen on their surface
describe interferons
not very long-acting
not very stable
toxic in high doses
effective in acute viral infection
cannot help virus-infected cells
what binds free irons in the human body?
transferrins
lactoferrins
ferritin
hemoglobin
what are antimicrobial substances?
iron-binding proteins
compete with pathogens for iron
required as a cofactor for many enzymes
what do pathogens produce to bind iron?
pathogens produce siderophores to bind
what is AMPS synthesis triggered by?
proteins
carbohydrate molecules on microbial cell surface
what does AMP act against?
bacteria
viruses
fungi
eukaryotic parasites
how does AMP kill?
by lysing cells
inhibiting cell wall synthesis
hydrolyzing DNA, RNA
what does AMP attract?
dendritic & mast cells
