L2.1 Neutrophils and macrophages in control of infection Flashcards
features of neutrophils
short lived numerous rapid infiltration infected itssue has granules phagoctyic does oxidative killing
features of macrophages
range from short lived to long lived
-diverse
-adapt to diff types of inflamm
does Nitorgen based killing
types of receptors innvolved in phagocytosis
opsonic and non opsonic receptors
what is opsonic receptors
interacts with AB stuck to pathgen
non opsonic receptors meaning
receptor that interacts with the pathogen directly
process of phagocytosis
the receptors interacts with pathogen or AB
- pathogen taken in and transported in phagosome
- phaogosome fuses with lysosomes to form phagolysosome
- pathogen broken down and killed off
types of neutrophil granules
primary, seco, terti
one eg of each neutrophil ggranule groups
1- lysosome
2-lactoferrin- extract Fe ion
3- gelatinase
what is NADPH oxidase
multi unit enzyme that produces toxic molecules using O2 to kill off MOs
process of oxidative killing using NAPH enzymes
- binding to the enzymes activates this
- transports superoxide anions into the phagosome lumen
- anions gets converted into hydrogen peroxide
- then into hypocholric acid (bleach)
- this kills MOs off
what is the disease called when there is NADPH oxidase deficiency
CGD
how dooes neutrophils die and through what process
by NETosis
- where the nuclear membrane break down
- chromatiin and DNA de condenses
- membrane ruptures
- the chromatin act like traps to catch any MOs
- other molecules helps like peptides, elastase
two kinds of macrophages
tissue resident and inflammatory
what the tissue resident macropahges
dervived from foetal progenitors (fetal stem cells), not from bone marrow
function of tissue resident macropahges
always in tissue as a barrier to pathogens
what are the inflamm macrophages
dervived from monocytes
- monocytes enter tissues then differentiate into macrophages
what is M1 macrophage
macrophages that is classically activated
- typically by IFN-γ (LPS), and produce proinflammatory cytokines, phagocytize microbes, and initiate an immune response.
what can M1 macrophage produce that is very toxic
nitric oxide
what is M2 maocrphages
alternatively activated by IL-1, IL-5
- produces urea and ornthine
name of process where neutrophils and macropahge move where they are needed
chemotaxis
chemotaxis process
- neutrophils and macropahges rolling in the plasma
- somehow they connect with E-selectin (endothelial cell)
- other cell surface molecules nd receptors tightly bind to these phago cells
- the phago cells squeeze between the membrane
- chemokines interact with the cells and initiate signalling
what is CARD9
CLRs (receptors mainly recognising fungi) use CARD9 to signal for pahocytosis, chemokine production, respiratory burst
when theres CARD9 mutation, why is there a brain infection
without the CARD9, the immune system cant signal to kill the fungal mass by phagocytosis
is the process of chemotaxis working normally w/o CARD9
yes apart from when the neutrophils cant interact with chemokines
what makes neutrohil attracting chemokines
when fungnal brain infection deteced, the CARD9+ microglia produces them
