Macrophages Flashcards
How does Mo extravasion differ from N extravasion?
involves Mo-specific chemokines and adhesion molecules
How are Mo more efficient than N?
sustained pathogenic activity and longer life span
What does Mo extravasion occur?
Immediately following N influx
What is Mo extravasion facilitated by?
release of Mo-specific chemokines and chemotactic agents
What are Mo-specific chemokines secreted by?
endothelial cells (CCL2-CCR4)
N (CCL4-CCR1)
M0 (CCL7-CCR2)
What are the chemotactic agents involved in Mo extravasion?
beta-defensins, chimerin, TNFalpha
What do E-cells and Mo express respectively during the tethering stage?
E-cells = P-selectin Mo = P-selectin glycoprotein ligand (PSGL-1)
What do E-cells and Mo express respectively during the rolling stage?
E-cells = E-selectin Mo = CD62L (L-selectin)
What do E-cells and Mo express respectively for adhesion molecules?
E-cell = ICAM 1&2 and VCAM 1 Mo = LFA-1 & MAC-1
What complement receptors do M0 express?
CD35 (CR1) and CD11b/CD18 (CR3)
What do complement receptors on M0 do?
enables the M0 to phagocytize microbes opsinised by C3 components
M0 express Fc receptors enabling them to?
carry out antigen-specific phagocytosis
What do mammalian M0 express?
high affinity CD64 and low affinity CD32 and CD16
What does expression of CD64 allow M0 to do?
Recognize single IgG-Ag complexes
What does expression of CD32 and CD16 allow M0 to do?
recognize multivalent immune complexes
M0 express CD71 enabling them to?
allow internalization of transferrin that has sequestered iron
What mechanisms of killing do M0 rely on?
oxidative and non-oxidative
M0 utilize the contents of what granulocyte?
N
What are the 2 subpopulations of M0?
pro-inflammatory M1 and anti-inflammatory M2
What does pro-inflammatory M1 do (Draw it)?
In the end it produces potent antimicrobial oxidants peroxynitrite and a nitrogen dioxide radical
What do M1 M0s secrete? What do these do?
IL12 and IL23 which are critical effectors for the acute phase intracellular infections
What can prolonged M1 M0 do?
damage host tissues and are involved in acute inflammatory disease (ex. gastroenteritis)