Cell mediated and humoral immunity (10)

Question 1

What cells can entire the secondary lymphoid tissue and possibly acquire membrane IgD?

Answer 1

Nieve B cells expressing membrane IgM.

Question 2

Where do activate B lymphocytes divide and differentiate?

Answer 2

2ndry lymphoid tissue.

Question 3

What mediates the humoral immune response?

Answer 3

Soluble antibody proteins.

Question 4

What is an example of secondary lymphoid tissue other than the lymph nodes?

Answer 4

Spleen.

Question 5

What Ig class is commonly found in dimers?

Answer 5

A

Question 6

What Ig class is commonly found as pentamers?

Answer 6

M

Question 7

What is the main antibody in tissues?

Answer 7

G

Question 8

What do the IgG subclasses mainly differ in?

Answer 8

Length and number of disulphides in hinge region.

Question 9

What can IgG activate?

Answer 9

Complement.

Question 10

What FC receptors does IgG bind to?

Answer 10

Phagocytes and NK Cells.

Question 11

What can IgG do that other immunoglobin classes can not?

Answer 11

Cross the placenta.

Question 12

What receptor can IgG bind to on the trophoblast?

Answer 12

FcRn

Question 13

What property of IgG means it can bind to FcRN on the trophoblast?

Answer 13

Long serum half life.

Question 14

What sort of response is IgG important in?

Answer 14

Secondary or memory responses.

Question 15

Why is IgM usually serum restricted?

Answer 15

It has a mw of 970,000 daltons

Question 16

What does IgM not have?

Answer 16

A defined hinge region Instead it has a ‘functional hinge’.

Question 17

IgM has 5 subunits. What else is associated with its structure?

Answer 17

J chain.

Question 18

What response is IgM important in?

Answer 18

Primary

Question 19

What is IgM good at (2 things)?

Answer 19

1. Being a agglutinator to a particular antigen

2. Activating complement

Question 20

Isotype switching occurs on which Ig class to produce what other Ig classes.

Answer 20

Occurs on M to produce G, A or E.

Question 21

What is usually required to allow for isotype switching?

Answer 21

T cell help via cytokines.

Question 22

The level of IgM is higher in the primary response compared to the secondary response. True or false?

Answer 22

False. It is the same level in both responses.

Question 23

IgA is either monomeric or dimeric. True or false?

Answer 23

False, it can also be polymeric.

Question 24

What subclass of IgA is found in primates?

Answer 24

IgA2

Question 25

What contains IgA?

Answer 25

Milk

Question 26

What Fc receptors does IgA bind?

Answer 26

Phagocytes.

Question 27

Why was IgA thought to originally have little importance?

Answer 27

Rapid catabolism.

Question 28

Where in the body is IgA present?

Answer 28

Secretions and mucosal surfaces.

Question 29

What Ig classes contain the J chain?

Answer 29

M and A.

Question 30

Where would you find IgA that contains the J chain?

Answer 30

Secretions.

Question 31

What is found with secretory IgA?

Answer 31

IgA dimer, J chain, secretory component.

Question 32

Polymeric Ig molecules (M and A) can undergo specilised transport via what receptor?

Answer 32

Poly- Ig

Question 33

How much IgA does mucosal lymphoid tissues produce each day?

Answer 33

5g.

Question 34

Where does the Poly-Ig receptor transport IgA/M too/ from?

Answer 34

From the submucosa via epithelial cells into the lumen.

Question 35

What is it thought IgA could have a role in?

Answer 35

Fighting infection passively.

Question 36

What percentage of serum Ig is IgD?

Answer 36

<1%

Question 37

Where is IgD found?

Answer 37

As an antigen receptor on many B lymphocytes, often with IgM.

Question 38

Where in the body do plasma cells/ B cells produce IgD? What does IgD do here?

Answer 38

Upper respiratory tract. Here it can interact with receptors on basophils inducing antimicrobial, inflammatory and B cell stimulatory factors.

Question 39

Monomeric IgM contains a functional hinge. What other Ig class also contains this?

Answer 39

IgE.

Question 40

What Ig class is found in the smallest amount in serum and what percent is it found at?

Answer 40

E. Only 0.0003% of serum is this class. This is a 'trace' level.

Question 41

What can IgE bind to?

Answer 41

High affinity FcR receptors on mast cells and basophils.

Question 42

What is released during mast cell degranulation?

Answer 42

Histamine and other inflammatory mediators.

Question 43

What is the main biological role for immunogloblins?

Answer 43

Label pathogens for elimation and destruction.

Question 44

All antibodies are at least what?

Answer 44

Divalent.

Question 45

What antibodies neutralize toxins?

Answer 45

G and A.

Question 46

What antibodies immobilise pathogens?

Answer 46

M.

Question 47

What antibodies prevent the pathogens binding to host?

Answer 47

G and A

Question 48

What antibodies agglutinate particles such as bacteria?

Answer 48

M and A.

Question 49

What do all antibodies do?

Answer 49

Form immune complexes with soluble antigen