Dendritic cells and migration, host innate immune receptors

Question 1

What do FcY receptors bind and what are it’s effects?

Answer 1

bind immune complexed consisting of IgG and antigens and induce internalization of the immune complexes. Can have activating or inhibitory effects. Leads to a signalling cascade.

Question 2

What do C-type lectins bind and what are it’s effects?

Answer 2

Have lectin domains which recognise carbohydrates, which can be pathogenic or self. Can have activating or inhibitory effect. Are good for recognition and phagocytosis but also antigen presentation.

Question 3

What do Toll like receptors (TLRs) bind?

Answer 3

Recognize PAMPs. Are on the plasma membrane where they bind dsRNA and on the endosome bind ssRNA (viruses).

Question 4

Which signals cause DC maturations?

Answer 4

Danger signals (DAMPs) cause DC maturation, (which increases MHC expression, co-stimulatory molecules, migration, production of inflammatory cytokines and makes antigen processing/presentation possible.)

Question 5

Which receptors recognise pathogens indirectly and to what does it lead?

Answer 5

Complement receptors and FC-receptors, this leads to opsonized microbes.

Question 6

Which receptors recognise pathogens directly?

Answer 6

scavenger receptors (SRs) and pattern recognition receptors (PRRs).

Question 7

What are examples of PAMPs and by what receptor are they recognised?

Answer 7

PAMPs are molecular signatures of invading pathogens, which can be cell wall components or DNA/RNA. They are recognized by PRRs.

Question 8

Which receptors are intercellular?

Answer 8

NOD-like receptors and RIG-I-like receptors are intercellular (in the cytoplasma).

Question 9

Which cytokine do all receptors stimulate?

Answer 9

All receptors stimulate NF-kB and this always leads to stimulating pro-inflammatory cytokines in the end.

Question 10

Which proteins are important in the TLR signalling pathway?

Answer 10

MyD88 (ssRNA/TLR7/8/9) and TRIF (dsRNA/TLR3).

Question 11

What do RIG-I-like receptors (RLRs) bind?

Answer 11

It recognizes viral RNA in the cytoplasm. It is TLR-independent.

Question 12

What do NOD-like receptors (NLRs) bind?

Answer 12

Recognize PAMPs and endogenous molecules in cytosol. Can be Intracellular bacterial peptidoglycans and other components of the cell wall.

Question 13

What protein is important in the NLR signalling pathway and to what does it lead?

Answer 13

the NALP protein oligomerizes and activates the inflammasome.

Question 14

What is the function of IL-1B?

Answer 14

IL-1B is central in all the immune responses. It is stimulating adhesion, triggers other cytokine production, affect chemokines for migration, affects neutrophils and NK cells but most importantly stimulates co-stimulation of T-cells and is essential in T17 development.

Question 15

What are examples of classical ways of vaccination?

Answer 15

Classical ways of vaccination are a whole-inactivated virus, a live-attenuated (weakened) virus, a protein subunit of a virus-like particle.

Question 16

What are examples of Next Generation vaccination?

Answer 16

Next-generation vaccination use viral signatures like a viral vector, DNA or RNA. Or use antigen-presenting cells (with adjuvant) with epitopes for the virus.

Question 17

What does the adjuvant in vaccination do?

Answer 17

It activates the PRR.

Question 18

What is important for cancer vaccination?

Answer 18

For cancer vaccination we need activation of CD8+ T cells which requires presentation in MHCI, so the antigen needs to be cytosolic or cross-presented. Therefore you need a high amount of antigen and maturation of DCs. The subset of DC is also important.