Flashcards in the Cells of Immunity Deck (45):
Range of white blood cells in body
4500, 11000 (7400)
Range of neutrophils
Range of Eosinophils
Phagocytes: Primary functions
ingest, destroy microbes, and "scavenge"
scavenger effect = phagocytic removal of dead matter and debris
Which cells are considered phagocytes?
neutrophils and macrophages
Steps in functional response to phagocytes:
recruitment of the cells to the sites of infection
Recognition of and activation by microbes
ingestion via phagocytosis
destruction of ingested microbes
Activated phagocytes secrete what? and why?
cytokines, promote immune responses
Neutrophils in Normal blood smear
also called polynuclear leukocytes because of nucleus is segmented into 3-5 connected bodies
diameter of a neutrophil
time wise, what part of the inflammatory process does the neutrophil mediate?
Neutrophils are produced in the
T/F Neutrophils arise from the same precursors that give rise to mononuclear phagocytes
an adult produces more than
1 x 10^11 neutrophils a day
How long do neutrophils circulate in the blood?
from a few hours to days
After entering tissues specifically, how long do neutrophils live?
1-2 days and then die
Production of neutrophils is stimulated by
a cytokine called granulocyte colony stimulating factor (G-CSF)
Neutrophil _____ _____ stain with ______ dyes
specific granules, neutral
Eosinophils stain with ____ dyes
Basophils stain with ___ dyes
Neutrophils respond to microbes of different sizes. How? What happens?
1.Neutrophils bind/internalize yeast cells
2.sequester them in phagosomes
3. fuse with azurophilic granules which release ROS and enzymes such neutrophil elastase into phag., contributing to their death
4. molecules as large as the hyphae (unicellular yeast) however cant be engulfed, so azurophilic granules are free to deliver their contents instead into the nucleus, which triggers chromatin decondensation and the release of NETs,
5. NETs contribute to immobalization and killing of extracellular organisms, but at the cost of tissue damage.
Neutrophil Extracellular Traps (NETs)
DNA and histones, decorated by proteins from primary granules and secondary granules
mitochondria can also serve as a source of DNA for NET
Formation of NETs
rapid, active process (occurs in 3 minutes)
possibly mediated by a cell death-dependent process referred to as NETosis
NETosis process (2 events)
chromatin condensation, nuclear membrane disintegration
4 medical conditions associated with NETosis
bacterial clearance, thrombosis, sepsis, SLE
Mast cells, Basophils, Eosinophils
Play role in innate AND adaptive immune responses
protect against helminths and reactions that cause allergic diseases
Mast, basophils, Eosinophils are active in innate AND adaptive immunity T/F
Common trait between Mast cells, basophils and Eosinophils
Share the common feature of having cytoplasmic granules filled with various inflammatory and antimicrobial mediators
what are in those granules the granulocytes all have?
inflammatory and antimicrobial mediators
Mast cells and staining
Mast cells contain histamine and other mediators, and stain purple with Giemsa
Basophils and staining
basophils stain blue with Giemsa
Eosinophils and staining
Eosinophils contain basic proteins and stain red with acidic dye and eosin
RED/BLUE/PURPLE indicates what cells dyed?
Purple = Mast cells (with Giemsa)
Blue = Basophils (with Giemsa)
Red = Eosinophils (with acidic dyes and Eosin)
Strategic Location of Mast Cells
Common at sites in the body that are EXPOSED TO THE EXTERNAL ENVIRONMENT such as the skin
found near blood vessels, where they can regulate vascular permeability and effector-cell recruitment
mast cells can modulate the behavior of neighborhood cell populations
Neutrophils: Specific Granule
Secretory phospholipase A2
Neutrophil: Azurophil granule
Granules in a Neutrophil include
Specific granules, azurophilic granules, tertiary granules
Mononuclear Phagocyte System includes...
circulating monocytes and resident tissue macrophages
Mononuclear Phagocyte System
macrophages play role in both innate and adaptive immunity
"Long lived macrophages" do what?
take up residence in specific tissues, and assume specialize phenotypes depending on the organ
Cells of the macrophage lineage arise from...
committed precursors in the bone marrow, driven by monocyte/macrophage colony-stimulating factor (M-CSF)
enter blood circulation, and then migrate into tissues, where they further mature into macrophages, especially during inflammation