Monocytosis & Monocytopenia Flashcards
Monocytosis –>
increased number of monocytes in the blood
monocytosis occurs in response to
chronic infections, autoimmune disorders, proliferation of macrophages can occur in tissues
sarcoidosis
proliferation of macrophages in tissues
Monocytopenia –>
low number of monocytes in the blood.
monoctypenia occurs in response to…
chemotherapy and endotoxemia
Origin and maturation of Mononuclear Phagocytes
fetus
HSC in fetus/yolk sac —> embryonic tissue mac precursor –> through blood –> differentiation into tissue kinds
(sinosoidal cells, kupfer cells, microglial cells, alveolar cells)
Origin and maturation of Mononuclear Phagocytes
adult
HSC in bone marrow –> monocyte/dendritic cell precursor –> monoblast –> monocyte –> macrophage
Macrophages: where are they found? how common? what do they do exactly?
not in circulation, but in tissues
ubiquitous
phagocytosis + APC
Macrophage expresses ___________ receptors
PRR and scavanger receptors
What kind of molecular signals do macrophages detect?
danger signals in the form of pathogens, foreign substances (silica/asbestos etc), dead dying cells
in what systems are MOs active?
both innate and adaptive
MO PRRs stimulate the production of cytokines ___ and ___
TNF and IL-1beta
MO roles
would repair
cytokines/chemokines (leukocyte recruitment)
deposition of extracellular matrix components at sites of injury
what are MO cytokines that push for the development of TH1 cells?
IL-12, TNF, IL-23
“feedback loop” with T cells
IL-12, TNF, IL-23 amplifies Th1 cells to produce IFN-gamma
MO cytokines suspected to be the main drivers behind chronic inflammatory autoimmune disease (name these diseases too)
IL-1beta and TNF
rheumatoid arthritis, atherosclerosis, pulmonary fibrosis, Crohn’s disease
Phagocytosis requires 3 things
1) energy from metabolism
2) additional cell membrane
3) cytoplasmic contractile protein system
what is the “scavenger function”
“ingest” and “destroy” microbes and damaged tissues
steps in phagocytosis
1) recruitment
2) recognition
3) ingestion via phagocytosis
4) digestion (destruction)
diapedesis vs chemotaxis
diapedesis: cellular emigration of phagocytes out of blood circulation into tissues
chemotaxis: when a phagocyte moves toward other cells/organisms by cytoplasmic streaming in response to chemotaxins.
chemotaxins
C5a in response LPS
N-formylmethionine (on bacterial cells, not eukaryotic cells)….phagocytes have a receptor for the N-terminus amino acids, which causes them to chase them
