Macrophages and Early Response to Microbial Invasion Flashcards
What is the structure of the nucleus of neutrophils?
it is condensed chromatin - segmented
What are neutrophils considered in regards to a bacterial infection?
it is the first line of defense
How long do neutrophils circulate?
8-10 hours
What are neutrophils removed by?
migration into the gut or by Kuepfer cells in the liver
How long can neutrophils live in normal tissue?
1-2 days
In tissues, how do neutrophils die?
via apoptosis
Are neutrophils innate or adaptive?
innate
What is the origin of neutrophils and macrophages?
bone marrow
Where are macrophages located?
in tissue
What is the function of macrophages?
sentinel cells, present antigen, kill and phagocytose bacteria, repair themselves, part of chronic infection, accumulate if neutrophil fails
What type of inflammation is associated with neutrophils?
acute
Is a macrophage or a neutrophil associeated with abcesses?
neutrophil
Is a macrophage or a neutrophil associeated with granulomas?
macrophages
What are the central roles that a macrophage plays in the immune system?
antigen presentation, sentinel cells, phagocytosis
Where are resident macrophages located?
bone, liver, brain, kidney, lung
What is the name and function of the resident macrophage in bone?
osteoclasts for remodeling
What is the name and function of the resident macrophage in the liver?
Kupffer cell for removing bacteria
What is the name and function of the resident macrophage in the brain?
microglial cells for clean up
What is the name and function of the resident macrophage in the kidney?
mesangial cell for trapping and removal of bacteria
What is the name and function of the resident macrophage in the lungs?
Pams for cleaning up bacteria
What is a sentinel cell?
defender cells that detect microbial entry and release pro-inflammatory cytokines to protect themselves and the cell
What are the types of sentinel cells?
dendrites, mast cells, and macrophages
Where are the patern recognition receptors found?
on cell surfaces and intercellular membranes
What do PRRs bind to and what is their function?
they bind to pAMPs and dAMPS to initiate the production of pro-inflammatory cytokines, produce IL2 (for NK cells), and produce nitroc oxide
What is a pAMP?
pathogen associated molecular patterns: molecules produced by microorganisms but not mammalian cells
What is a dAMP?
damage associated molecular patterns: molecules found within mammalian cells and released when the cell is damaged or dies
How to pAMPs and dAMPs work?
Bind to PRR to Upregulate proinflammatory cytokines which activate the innate immune system, neutrophils, macrophages, and the adaptive immune system to be ready to respond
What does a macrophage do when something has bound to its pattern recognition receptor?
Initiate the production of pro-inflammatory cytokines, produce IL2 (for NK cells), and produce nitroc oxide
Define inflammasome.
complex in the cytosol that is important in the release of pro-inflammatory cytokines
What are major pro-inflammatory cytokines?
IL1, IL6, and TNFs
How would the body react if small amounts of pro-inflammatory cytokines were released?
local inflammation
How would the body react if moderate amounts of pro-inflammatory cytokines were released?
animal looks and feels sick - fever, lethargy, loss of appetite, neutrophilia
How would the body react if large amounts of pro-inflammatory cytokines were released?
vasodilation, damages endothelial cells, low cardiac output, lung fills with fluid (septic shock) – can kill you
Explain the immunologic basis for the most common reason why a puppy may develop a low-grade fever and be lethargic 24 hours after a vaccination.
Moderate quantities of pro-inflammatory cytokines
How long does it take for the acute phase protein response to occur?
made within 24 hours
Where does the acute phase protein response occur?
in the liver
What is the purpose of the acute phase protein response?
control the infection until antigen specific response can happen
What are the major acute phase proteins?
serum amyloid A and P, and C reactive protein
What is the function of C reactive protein?
acts like an opsonin and activates compliment
What is the funciton of serum amyloid P?
can activate compliment
What is the function of serum amyloid A?
it is a chemoattractant for neutrophils, monocytes, and T cells
What does negative acute phase protein mean?
a protein that goes down in the inflammatory response
What is an example of a negatibe acute phase protein?
albumin
What are the 3 general types of macrophage activation?
innate, classical activation, and alternative activation
What molecules are associated with innate microphage activation?
PRRs which are activated by pAMPs and dAMPS
What is the function of innate macrophage activation?
lysosomal enzyme production and phagocytosis
What molecules are associated with classical activation of macrophages?
M1 macrophages activated by interferon gamma
What is interferon gamma secreted by?
T1 helper cells and NK cells
What is the function of classical activation of macrophages?
produce nitric oxide, proinflammatoru, antimicrobial, early in response
What molecules are associated with alternative activation of macrophages?
IL4, IL10, and IL13 - M2 macrophages
What is the function of alternative activation of macrophages?
tissue repair, promote healing, late in response, decreased killing, increased MHC II expression
What are the 5 cardinal signs of acute inflammation?
redness, heat, swelling, pain, and loss of function
What causes redness and heat?
increased permeability and dilation of blood
What causes swelling?
increased vascular permeability
What causes pain?
prostaglandins which act on nerve endings, swelling too
What causes loss of function?
the pain and swelling
