immune response to bacterial pathogens

Question 1

innate immunity

Answer 1

rapid response
relatively non-specific
no memory
particularly important in our response against bacterial pathogens

Question 2

what does the innate imunity best deal with?

Answer 2

the earlier stages of pathogenesis an some effect on the early stages of replication

• exposure
• adherence
• invasion
• replication

Question 3

physical and chemical barriers to bacterial attachment and invasior

Answer 3

skin
airways
gut

Question 4

antimicrobial peptides (AMP’s)

Answer 4

such as defensins
they have a charge and this charge works well to break down the bacterial cell membranes
especially the gram negative bacteria
it binds to specific lipid receptors and disrupts the bilayer and the membrane bound machinery.

Question 5

Lysozymes

Answer 5

especially active against gram positive bacteria.

it breaks the bonds between the glycopeptides. it breaks the NAM and the NAG apart in the glycopeptides

Question 6

inflammatory response stage 1

Answer 6

the macrophages phagocytose and antigens that have entered and the mast cell releases cytokines

Question 7

killing and digestion of phagocytosed microbes

Answer 7

low pH - acid environment 
reactive oxygen and reactive nitrogen intermediates 
enzymes 
- proteases
- lipases
- nucleases

Question 8

6 stages pf phagocytosis

Answer 8

1. pseudopodia formation
2. adherence of bacteria to phagocytic cell
3. ingestion
4. vacuole/ lysosome fusion
5. killing and digestion
6. elimination (exocytosis)

Question 9

alternative pathway for complement activation

Answer 9

microbe detection

which leads to label, recruit and destroy

Question 10

classical pathway for complement activation

Answer 10

antibodies attached to the microbe which leads to label, recruit and destroy.

Question 11

lectin pathway for complement activation

Answer 11

mannose binding lectin to the microbe which leads to label (C3b), destroy (C9) and recruit (C3a)

Question 12

destroy

Answer 12

membrane attack complex formation
-pores in bacterial cell walls - death
C9

Question 13

label

Answer 13

opsonisation
labels pathogens which bind to complement rectors on phagocytes
C3b

Question 14

recruit

Answer 14

complement proteins act as peptide mediators of inflammation and recruit phagocytes
C3a and C5a

Question 15

how do microbes avoid innate immune responses?

Answer 15

make molecules that resist antimicrobial peptides
evase uptake by encasing in a slimy capsule
prevent fusion of phagosome with lysosome during phagocytosis