Immunology 2

Question 1

What are primary (or central) lymphoid tissues?

Answer 1

Where lymphocytes develop

Question 2

What are secondary lymphoid tissues?

Answer 2

Where the adaptive immunity response are initiated

Question 3

Give an example of primary lymphoid tissue?

Answer 3

Bone marrow, thymus

Question 4

Give an example of secondary lymphoid tissue?

Answer 4

Lymph nodes, Spleen, Mucosa-associated lympohd tissue (e.g.peyers patches, appendix, BALT)

Question 5

What is a thymocyte?

Answer 5

An immature T cell that moves out tof the bone marrow and migrates into the thymus

Question 6

How many lobes does the thymus have?

Answer 6

2. It is bi-lobed.

Question 7

Lobules are separates by connective tissue called what?

Answer 7

Trabeculae

Question 8

Each lobule has an outer WHAT and inner WHAT?

Answer 8

outer cortex

inner medulla

Question 9

What do nurse cells do?

Answer 9

They are involved in selecting thymocytes to ensure they are mature when they leave the thymus

Question 10

The cortex is

a) loosely packed with cells
b) tightly packed with cells

Answer 10

b) tightly packed with cells

Question 11

The medulla is

a) loosely packed with cells
b) tightly packed with cells

Answer 11

a) loosely packed with cells

Question 12

The site of positive selection is

a) the cortex
b) the medulla

Answer 12

a) the cortex

Question 13

The site of negative selection is

a) the cortex
b) the medulla

Answer 13

b) the medulla

Question 14

Cd stands for what?

Answer 14

cluster of differentiation

Question 15

Mature cells are all CD3+. True or false.

Answer 15

True

Question 16

CD8 interacts with

a) MHC class 1
b) MHC class 2

Answer 16

a) MHC class 1

Question 17

CD4 interacts with

a) MHC class 1
b) MHC class 2

Answer 17

b)MHC class 2

Question 18

Immature T cells are CD3-, CD4- and CD8-. What is this state called?

Answer 18

Double negative thymocytes

Question 19

Interaction with what causes the production of CD3, CD4, CD8 in T cells?

Answer 19

Cortical Epithelial cells and Dendritic cells

Question 20

Immature T cells activated to express CD3, CD4 and CD8, following positive selection of cells in the thymus, are called what?

Answer 20

double positive thymocytes

Question 21

CD4+ t cells are known as

Answer 21

helper T cells

Question 22

CD8+ t cells are known as

Answer 22

cytotoxic T cells

Question 23

What is an antigen?

Answer 23

Molecule that can be recognised by lymphocytes as foreign and has a defined shape.

Question 24

Antigens are transported tot he lymph nodes by cells such as?

Answer 24

dendritic cells.

Bacteria can also be transported free

Question 25

Lymph nodes are situated at sites prone to infection. True or False.

Answer 25

True

Question 26

What are bean shaped structures which filter and trap antigen from the lymph.

Answer 26

Lymph nodes

Question 27

Where in the lymph nodes do B cells get activated?

Answer 27

Cortex

Question 28

Where in lymph nodes do T cells get activated?

Answer 28

Paracortex

Question 29

What is the general name of how lymphocytes cross the endothelium?

Answer 29

rolling behaviour

Question 30

In rolling behaviour L-selectin on the lymphocyte binds to what? And with what affinity?

Answer 30

Either glycCAM-1 (proteoglycan) or CD34 on the high endothelial venial (HEV). Low affinity

Question 31

What is chemokine? | What does it do?

Answer 31

Chemokine is a chemoattractant cytokine which binds chemokine receptors on lymphocytes giving activation signal for adhesion molecule Ifa-1, which changes conformation and binds very tightly to ICAM-1.

Question 32

What affinity is the interaction between ICAM-1 and Ifa-1 in rolling behaviour?

Answer 32

Very tight

Question 33

What is the Germinal Centre?

Answer 33

The site where you get the proliferation of an activated B cell (releases b cells that differentiate into plasma cells into the lymphatic which leads to the blood stream)

Question 34

What are lymphoid follicles?

Answer 34

A loose network of follicular dendritic cells (FDCs) in a region rich in B cells.

Question 35

What is the difference between FDCs and DCs?

Answer 35

``` FDC are not leukocytes and are not derived from bone marrow precursors. They are also not phagocytic and do not express MHC class II proteins. ```

Question 36

The spleen is composed of red and WHAT pulp?

Answer 36

red and white pulp

Question 37

Is it the red or white pulp that acts as a lymph node?

Answer 37

white pulp

Question 38

What happens in the red pulp?

Answer 38

- red blood cells disposed of

Question 39

What is the structure of the white pulp?

Answer 39

Lymphocytes surround a central arteriole forming Periarteriolar Lymphoid Sheaths (PALS). Primary follicles are attached to PALS where you get differentiating lymphocytes

Question 40

MALT protects mucus membranes lining what?

Answer 40

digestive, respiratory and urogenital systems

Question 41

BALT is a form of MALT. True or false

Answer 41

True

Question 42

What is the function of MALT?

Answer 42

protects the gut

Question 43

peyers patches are a form of what?

Answer 43

lymph nodes. They are a form of GALT

Question 44

What is an M cell?

Answer 44

An M cell (microfold) is a specialised cell above the peyers patches which transportantigen from the gut into the lymphoid tissue

Question 45

What are intraepithelial lymphocytes?

Answer 45

specialised lymphocytes that localise in the epithelial layer (they are able to leave and circulate also)

Question 46

Naiive T cells have L-selectin which binds WHAT and alpha4beta7 which binds WHAT?

Answer 46

L-selectin binds GlyCAM-1 | alpha4beta7 binds MadCAM-1

Question 47

Cells activated in peyers patches have high/low a4b7 and high/low L-selectin.

Answer 47

cells activated in PPs have high α4b7 and low L-selectin which helps them re-enter the secondary lymphoid organ where they encountered Antigen

Question 48

what does a4b7 do

Answer 48

Encourages localisation in mucosal tissue cell the first encountered the antigen