14. Listeria monocytogenes Flashcards
L. monocytogenes can cause what diseases aside from listeriosis?
Sepsis and meningitis
Where does L. monocytogenes reproduce?
Liver cells
3 L. monocytogenes virulence factors?
- Adhesins (InlA, InlB)
- Vacuole degradation (LLO, PLC, Mpl)
- Actin nucleation (ActA)
3 different types of vacuole degradation molecules?
Pore-forming hemolysin, phospholipase hemolysin, metalloprotease
Motif found on L.monocytogenes internalins?
Leucine-rich repeats (LRRs)
Which part of internalins interacts with host cell receptors?
N-terminal
What does InlA bind to? InlB?
InlA - E-cadherin on intestinal epithelial cells
InlB - Met receptor
How are lipoteichoic acid (LTA) associated with internalins?
InlB is non-covalently attached to LTA, which is anchored to the inner membrane
How are actin and clathrin recruited during L. monocytogenes invasion?
InlA/InlB interaction with E-cadherin/Met
Why isn’t the cell lysed once L.monocytogenes escapes from the vacuole?
Because LLO activity is mazimized in a vacuole and minimized in the cytosol
Main difference between LLO and PLC in how they function for vacuole escape?
LLO - form pores in membrane
PLC - degrade phospholipids by cleaving phosphodiester bond
In L.monocytogenes, ActA mimics host cell ______________
WASP actin nucleating factors
ActA is anchored non-covalently to _______ via its C-term
cell wall
How are actin comet tails formed by ActA?
ActA recruits VASP that recruits profilin (actin monomer binding protein) that recruits actin => polymerization forms comet tails
What part of L. monocytogenes is a PAMP that induces sepsis?
Lipoteichoic acid (LTA)
