Immune evasion and subversion Flashcards
What is antigenic variation in pathogens
Pathogens alter their surface antigens to avoid immune detection
How do pathogens hide from the immune system
The hide in imme priveleged compartments
What is molecular mimicry in immune evasion
Pathogens produce hostlike molecules to avoid detection
How do some pathogens eliminate immune cells
Superantigens induce massive t cell activation then apoptosis
Hiv selectively depletes CD4 cells
How do pathogens skew immune response
Pathogens manipulate immune responses to favour less effective responses
Why are some resistance to killing mechanisms developed by pathogens
tb inhibits phagosome maturation
listeria - uses listerolysin to escape phagosome
What are the host immune mechanisms involved in the molecular arms race
Redundancy in immune genes
PRRs
Adaptive immunity allows real time evolution
Advantages pathogens have in the arm race
High replication rates and muation rates enable rapid evolutions
How does iron acquisition battle play out between host and pathogen
macrophages reduce fe2+ availabilty and lactoferrin sequesters iron
pathogen strategies occur as well
How does mtb evade immune response
prevents phagosome maturation and inhibits acidification
LAM blocks signalling
Zmpa secretion block inflammasome activation
Arginase 1 reduces NO production
How does listeria monocytogenes evade killing
Escape into cytoplasm using LLO
What are the key immune evasion strategies of the plague( yersinia pestis)
Weak LPS and TLR4 detection
TType 3 secretion system disable host immune signalling
YopJ inhibits TLR signalling by removing ubiquitin markers
What happens if the LPS or TYpe 3 secretion system of yersinia pestis is interrupted
Virulence signficantly drops
