Flashcards in Lecture 2: Cells of the Immune System 2 Deck (30)
What do the Common Lymphoid Progenitors differentiate into?
1. NK cells
2. B cell lymphocytes
3. T cell lymphocytes
What do the Common Myeloid Progenitors differentiate into?
3) Mast cells
8) Dendritic cells
What determines what an HSC will differentiate into?
Which 2 cytokines signal to make common myeloid progenitors?
Which cytokine signals to produce common lymphoid progenitors?
After differentiating and maturing, where do immune cells go?
Into the blood; bits of digested pathogen are brought to lymphoid organs by other immune cells allowing for lymphocytes to find their match
lymphocytes only go to the site of infection when ________
they met their specific pathogen in the lymphoid organ
What are the 4 common lymphoid depot sites where lymphocytes meet their pathogen?
1) Lymph nodes
2) Mucosal lymphoid tissue
4) Tonsils and Adenoids
Route of activated lymphocyte back to the blood stream from the lymph and ultimately to the site of infection?
lymph drainage into thoracic duct --> left subclavian vein
This system of matching pathogen and lymphocyte is dependent on what?
COOPERATION between adaptive and innate systems (innate presents pathogen to adaptive and adaptive eradicates)
What are the most abundant white blood cells? (Which also happen to be the most important front line defense cells of innate system)
What is the other name for neutrophils and what is the morphological hallmark of neutrophils?
PMNs; 3-lobed nucleus (think 3 letters, 3 lobes)
What are the 2 methods in which neutrophils kill pathogens?
2) extracellular killing via granule release (also damages nearby tissue) and NETs (neutrophil extracellular traps)
True or false: neutrophils are long lived
FALSE, they usually die after one round of phagocytosis (dead neutrophils = pus)
What is the process of antigen presentation?
Dendritic cell constantly sampling environment, finds pathogen, carries fragment from infection thru lymph where it meets with a T cell for "debriefing"
T cell can then become an effector cell and go out to fight battle
Where does the lymph meet the blood stream?
Subclavian vein (thoracic duct empties into it)
What makes up the myeloid family?
mast cell, basophil, neutrophil, eosinophil, macrophage, myeloid dendritic cell
Which are more common, myeloid or lymphoid cells?
MYELOID (think granulocytes like neutrophils)
What are the two kinds of granules present in neutrophils?
1) Primary (azurophilic) - direct toxic/enzymatic activity
2) Secondary - free radical formation
Do tissues have resident populations of neutrophils?
NO, they are constantly circulating, only migrate to tissues during times of infection
What kind of cells are the work horses of the adaptive immune response?
Can macrophages recognize specific pathogens?
No, but they recognize CONSERVED MICROBIAL PATTERNS (like gram negative bacteria, activating macrophage TLR4)
What innate cells initiate adaptive immunity?
Dendritic cells (present antigen to immune system and signal to T-cells to proliferate)
Describe the morphology of eosinophils and their function?
bi-lobed nucleus, kill parasites
Eosinophils trigger ______ cells which release histamine causing vasodilation
What is the function of Mast cells?
release histamine and heparin (stored in granules)
What effect does the release of histamine have on blood flow?
INCREASES it (vasodilates area)
What are the front line defense cells of lymphoid origin?
Natural killer cells (have distinctive granular cytoplasm)
Main function of NK cells?
To contain infection (recognizes cells that don't look quite right like viral infections)