PAMPs that drive the Innate Immune Response

Question 1

How does the host respond to O-Ag of LPS?

Answer 1

• O-Ag triggers the alternative pathway of complement
• Gram-negative bacteria should be sensitive to MAC
• C3a and C5a stimulate inflammation and attract neutrophils to gut lumen

Question 2

How does the host respond to Lipid A of LPS?

Answer 2

Lipid A is recognized by TLR4

Question 3

How does the host respond to peptidoglycan?

Answer 3

• TLR2 responds to peptidoglycan in all extracellular bacteria
• TLR2 also responds to teichois and lipitechoic acids of gram negative bacteria

Question 4

How does the fost respond to flagella?

Answer 4

• Flagella are recognized by TLR5