L41. Adaptive Immunity

Question 1

Name the 2 types of adaptive immune response.

Answer 1

Cell-mediated response

antibody (humoral) response

Question 2

Cell mediated immunity: which cells is it driven by?

Answer 2

T cells

Question 3

Cell mediated immunity : what does it involve the activation of?

Answer 3

macrophages
natural killer cells
cytotoxic T-lymphocytes

Question 4

Humoral immunity : which cells drive it? Why?

Answer 4

B-cells produce antibodies

Question 5

How does immunological memory occur?

Answer 5

When a pathogen is remembered by a signature T cell and/or B cell receptor

Question 6

What is the time frame for adaptive immunity?

Answer 6

4-7 days from the start of infection

Question 7

Describe the 2 stages following “recognition by naïve B and T cells”.

Answer 7

2. Clonal expansion and differentiation

3. Removal of infectious agent

Question 8

Name 3 adaptive immunity receptors

Answer 8

1. T cell receptors
2. B cell receptors
3. MHC proteins

Question 9

What do T cells do?

Answer 9

Give rise to cellular immunity.
Can respond to many antigens, called “T cell repertoire”.
“Thymic education” means they only respond to foreign pathogens

Question 10

What is the role of CD4+ cells?

Answer 10

T helper cells which help support other immune cells to fight threats

Question 11

What are CD8+ cells?

Answer 11

Cytotoxic T cells which destroy infected self cells

Question 12

What do T-regs do?

Answer 12

Regulate or suppress other immune cells

Question 13

How do all cells start?

Answer 13

As naïve cells and have protein specific receptors

Question 14

Name the co-receptors of the following and what they each bind to.
CD8
CD4

Answer 14

CD8 has a co-receptor that binds to MHC1

CD4 has a co-receptor that binds to MHC2

Question 15

What is CD3?

Answer 15

A co-receptor involved in CD4 and CD8 T-cell activation

Question 16

What are most T cell receptors made of?

Answer 16

alpha and beta chains

Question 17

Name the 2 regions which make up the T cell receptor.

Answer 17

Constant region

Variable region

Question 18

Which genes make up the variable region, and which chains are they found on?

Answer 18

V (variable) (alpha and beta)
J (joining) (alpha and beta)
D (diversity) (beta only) (closes to B in alphabet)

Question 19

How are genes re-arranged, and by which enzymes?

Answer 19

Somatic recombination by RAG enzymes

Question 20

Name the 2 types of T cell selection after the thymus interaction.

Answer 20

Positive selection

Negative selection

Question 21

What happens to positively and negatively selected CD4/CD8 cells?

Answer 21

Leave the thymus and regulate in the blood/lymphatics.

Question 22

*Even although cells which leave the thymus (to regulate in the blood) are educated, what cell type are they still classed as?

Answer 22

“Naïve T cells”

Question 23

What do immature dentritic cells do?

Answer 23

Take up the antigen to be processed in the epidermis. They migrate to the lymph nodes and mature on the way.

Question 24

What does “priming” refer to?

Answer 24

The 3 signals required for activation and fate determination of T cells.

Question 25

Name the middle step. 1. Activation of T cell by T cell receptor and MHC2. (this is known as anergy if step 2 is absent) 2. ___________________ 3. differentiation into subsets of effector T cells (using cytokines)

Answer 25

1. Activation of T cell by T cell receptor and MHC2. (this is known as anergy if step 2 is absent) 2. Survival and clonal expansion of T cells using CD28 3. differentiation into subsets of effector T cells (using cytokines)

Question 26

Name the 5 CD4 cell subsets.

Answer 26

``` Th1 Th2 Th17 Tfh Treg ```

Question 27

Give the role and source of Th1

Answer 27

supporting macrophage function | interferon y

Question 28

Give the role and source of Th2

Answer 28

supporting humoral responses and allergic reactions | interleukin 4,5 and 6

Question 29

Give the role of Th17

Answer 29

Supports innate immune responses

Question 30

Give the role of Tfh

Answer 30

T follicular helper cells work with b cells for antibody production

Question 31

Give the role of Tregs

Answer 31

Immune suppression, inhibit T cell and dendritic cell activation.

Question 32

What activates CD8 cells?

Answer 32

T cell receptor and MHC1 interaction

Question 33

What does CD8 activation result in?

Answer 33

Induces host cell apoptosis | produces enzymes

Question 34

What is the activation of T cells called? What does it result in?

Answer 34

Activation is called priming. | Results in the generation of memory T cells