6 - R immunité

Question 1

Choose an innate immune receptor and discuss its function; explain molecular mechanisms

Answer 1

That’s the exam question

Question 2

What is the difference between innate and adaptive immunity?

Answer 2

Innate immunity is molecular pattern specific and provides a 1st line of defense against pathogens. We are born with the genes that code for the innate imm cells and they provide a link to the adaptive immune system

Adaptive : 2nd line of defense that is activated by the innate imm system. There is rearrangements of genetic material for specific defense that is antigen specific (higher resolution recognition). This triggers clonal expansion of lymphocytes

Question 3

Name the 6 innate immune receptors and their main role.

Answer 3

1) TLR = membrane PRR → mediate cytokine production
2) NLR = cytoplasmic PRR = mediate cytokine production
3) RLR (cytoplasmic) = protect against foreign RNA (viral response)
4) CLR (C-type lectin-R) = membrane PRR
5) FPR ( bacterial/mitochondrial)
6) SR = membrane = large # ligands like cholesterol and lipids

Question 4

Describe the function and molecular mecanisms of RLR’s

Answer 4

1 ) RLR = RIG-1-like reception

2) Rôle = Discrimination between host and foreign RNA = important in antiviral response
3) Mecanism

• Host mRNA = espaces recgonition by 7methyl-Guasine 5’ ends
• tRNA = 5’ clivage + modifications
• RIG-1 is inactivated by structure preventing CARD activation (Caspase activated recruitment domain)
• dsRNA or Tri-phosphate-5’ viral RNA recognized and bind to RIG-1
• Recruitment of ATP and release of CARD
• CARD interacts with IPS-1 on mitochondrie outer membrane
• Transduction ↑ IRF3/7 = ↑ IFN
• Transduction = ↑ NF-kB which both lead to cell death.