Antimicrobial peptides

Question 1

What is the role of antimicrobial peptides in the immune response towards the bacteria

Answer 1

The first line of response towards extracellular bacteria, Since AMPs always are produced and stored before pathogen encounter, as a part of the innate immunity. Since the adaptive and humoral response takes a lot of time, usually bacteria is killed in this way

Question 2

What is the mechanism of antimicrobial peptides on bacteria

Answer 2

• Inhibit cell-wall synthesis of the bacteria
• Activation of autolysin - making the bacteria to kill itself
• Inhibit the synthesis of DNA, RNA and peptides
• inhibit the enzymatic activity

Question 3

Which are the four antimicrobial peptides in humans

Answer 3

• Alpha-defensins
• Beta-defensins
• Cys-free linear peptides
• Saposin family

Question 4

What is the function of antimicrobial peptides in the body

Answer 4

• Antimicrobial - kill harmful microbes
• Immunomodulatory - increase or dampen, depending on the sitatution
• Homeostasis - control of the microflora

Question 5

Give examples of how bacteria can evade antimicrobial peptides

Answer 5

S.typhimurium - make its membrane harder to penetrate
S.aureus - make the surface less charged
N.gonnorhoeae - efflux pump family