Immunology 02. Linking II and AI

Question 1

Answer 1

Question 2

Answer 2

Question 3

Answer 3

Question 4

Answer 4

Question 5

Answer 5

Question 6

Answer 6

Question 7

Answer 7

Question 8

Answer 8

Question 9

Answer 9

Question 10

Answer 10

Question 11

Answer 11

Question 12

Answer 12

Question 13

Answer 13

Question 14

Answer 14

Question 15

Answer 15

Question 16

Answer 16

Question 17

CD4 and CD8 tackle what kinds of antigen?

Answer 17

CD4 and CD8 tackle what kinds of antigen?
CD4: exogenous sources of antigen presented on MHC II
CD8: endogenous sources of antigen presented on MHC I

Just remember I x 8 = II x 4 Ezpz :))

Question 18

Function of APCs? (3 functions)

Answer 18

Function of APCs? (3 functions)
1) Capture Antigens and bring them to correct place (peripheral lymphoid organs, through where naive lymphocytes circulate)

2) Present antigens in the form that can be recognized by specific lymphocytes

T cells: MHC associated peptides
B cells: Naive antigens, APCs including macrophages

3) provide second signals (B7) for T cell activation

Question 19

Functions of T lymphocytes?

Answer 19

Functions of T lymphocytes?
1) Primary defence against intracellular microbes
2) Activation of other cells (phagocytes, B cells)
3) Killing of infected cell

Question 20

Give 4 reasons why dendritic cells are the most efficient APCs for initiating immune response? LRMM

Answer 20

Give 4 reasons why dendritic cells are the most efficient APCs for initiating immune response? LRMM
- Location
- Receptors for capturing and recognising microbes
- Migration to T cell zones of lymphoid organs
- Maturation during migration

Question 21

Maturation of DC results in what changes in the DC?

Answer 21

Maturation of DC results in what changes in the DC?

Increase levels of MHC, induce costimulators such as B7, CD40 and decrease endocytic capacity

Question 22

Most efficient APC?

Answer 22

Most efficient APC?
Dendritic cells

Question 23

Most important professional antigen presenting cells?

Answer 23

Most important professional antigen presenting cells?
Dendritic cells

Question 24

Naive T cells bind peptide in association with MHC molecules via ??

Answer 24

Naive T cells bind peptide in association with MHC molecules via ??
TcR

Question 25

T cell activation requires which 3 signals?

Answer 25

T cell activation requires which 3 signals?
Peptide/MHC complex signal

Costimulatory signals

Cytokine signals

Question 26

TCR makes contact with both

Answer 26

TCR makes contact with both
MHC and peptide

Question 27

What are each type of T cells good at?

Answer 27

What are each type of T cells good at?
Helper T cells good at stimulating Ab production by B cells (Th2), macrophages to fight phagocytosed microbes (Th1).

**Cytotoxic T **cells (CD8+) kill infected cells and eliminate reservoirs of infection which are usually cytosolic and endogenous

Question 28

What are the dual specificities that t cells antigen receptors have?

Answer 28

What are the dual specificities that t cells antigen receptors have?
1) for peptide antigen (responsible for specificity of immune response)
2) for polymorphic residues of self MHC molecules (responsible for MHC restriction)

**Meaning TcRs “see” and recognise both peptide antigens and self MHCs **

Question 29

What happens to t cell in thymus, secondary lymphoid organs and site of infection?

Answer 29

What happens to t cell in thymus, secondary lymphoid organs and site of infection?
1) T cell selection
2)* T cell activation*
3) T cell effector function

Question 30

What kind of t cells are selected in the thymus?

Answer 30

What kind of t cells are selected in the thymus?
Only T cells that “see” MHC molecules in the thymus are selected to survive (binds weakly to self MHCs, aka positive selection)

Question 31

What kind(s) of stimulation does T cell need to be activated?

Answer 31

What kind(s) of stimulation does T cell need to be activated?
T cells need both the **specific signal from the antigen **and the co-stimulatory signal to be activated

(and cytokine signals)