Lecture 16

Question 1

What are the two types of immune responses?

Answer 1

Innate and adaptive

Question 2

What is the first line of defense of immunity?

Answer 2

Epithelial barriers
Skin
Bronchial
Gut

Question 3

What are features of the microbiological barrier?

Answer 3

Produce metabolic products to stop pathogen growth
deplete nutrients for pathogens
provide protective layer

Question 4

Where are immune cells produced?

Answer 4

Bone marrow,
Blood
Lymph nodes

Question 5

What are the two types of immunometabolism?

Answer 5

systemic immunometabolism
cellular immunometabolism

Question 6

What are the function of macrophages?

Answer 6

phagocytosis
cytokine production
antigen presentation

Question 7

What are the functions of dendritic cells?

Answer 7

Antigen uptake
cytokine production
antigen presentation

Question 8

What are the function of neutrophils

Answer 8

phagocytosis

Question 9

What is the basic principle of the immune system?

Answer 9

recognise invading microorganisms
formulate a response to clear the infection

Question 10

What are PAMPs?

Answer 10

Pathogen associated molecular patters: Unique to pathogens and recognised by immune system

Question 11

What are PRRs (Patterns recognition receptors)?

Answer 11

PRRs recognize PAMPs (evolutionary conserved)

Question 12

What are the three types of PRRs?

Answer 12

Toll like receptors (TLR)
Nod like receptors (NLR)
Rig like helicases (RLH)

Question 13

What are TLRs (Toll like receptors)

Answer 13

Transmembrane protein recognize PAMPs thorugh ligand binding domain

Question 14

What are NLR and RLH?

Answer 14

soluble molecules that scan the cytoplasm for PAMPs

Question 15

What are TLR recognized by?

Answer 15

TIR domain and Leucine rich repeat (LRR) which recognizes the PAMPs

Question 16

What is the TLR cascade?

Answer 16

TLR acivates ubiquitine ligase -> activating NfkB and induce cytokine production in the nucleus

Question 17

What are DAMPs (Danger Associated Molecular
Patterns) and what do they do?

Answer 17

DAMPs are released when cells are dying and can activate PRRs (serve as warning to other cells)

Question 18

What are cytokines?

Answer 18

peptides that mediate communication between cells
mediate immune response and inflammation

Question 19

What are chemokines?

Answer 19

Peptides that recruite immune cells to infection or injury

Question 20

How are pathogens cleared by the immune system?

Answer 20

Phagocytosis (bacteria)
Killing of pathogens (parasites)
killing of host cells (viruses)

Question 21

How are pathogens cleared by macrophages?

Answer 21

Recptors on mycrophages bind microbes and their components -> internalize them and break them down in phagolysosomes

Question 22

What are B-cells?

Answer 22

Sole producers of antibodies

Question 23

How can antibodies recognize several different antigens?

Answer 23

The posses a region of hypervariability for binding to antigens

Question 24

WHat do T-cells do?

Answer 24

mediate immune protetcion (CD4 and CD8 cells)
recognize antigens by MHC presentation

Question 25

What do CD8 T-cells do?

Answer 25

Recognize antigens on cell surface and kill the cells. Antigen is presented on MHCI cells

Question 26

What do CD4 T-cells do?

Answer 26

MHCII antigen presentation -> activate B-cells and macrophages

Question 27

Why are lymphocytes so special for immune responses?

Answer 27

Each lymphocyte only recognizes 1 antigen and there are millions which results in millions of different specificities

Question 28

How is it possible to produce millions of different antigen recpetors when the genome only has 20000 genes? (lymphocytes)

Answer 28

Through gene rearrangment (V(D)J recombination) 1 V 1 D and 1 J gene come together and are further augmented by deletions / insertions to generate millions of antigen receptors

Question 29

How do antigen receptors discriminate between self and non-self?

Answer 29

self reactive lymphocytes are degraded (clonal deletion) only mature lymphocytes continue

Question 30

What is the clonal selection hypothesis?

Answer 30

Lymphocytes upon interacting with forgein antigen differentiate into effector cells and memory cells which bear the same receptors (clonal expansion)