Foundations in Immunology 3

Question 1

What are properties of the adaptive immune system that is different to the innate immune system?

Answer 1

Very specific

Immunological memory

Question 2

What antigen do B cells use to recognise free antigens?

Answer 2

BCR (surface IgM)

Question 3

What receptor do T cells use when they are being shown an antigen?

Answer 3

MHC

Question 4

How do antibodies from a memory cell bind to antigens compared to regular cells?

Answer 4

With much higher affinity

Question 5

What is a naive B cell?

Answer 5

B cell that has not been exposed to an antigen

Question 6

What happens once a naive B cell is exposed to an antigen?

Answer 6

Becomes a memory B cell or a plasma cell

Question 7

What are the 2 kinds of adaptive immunity?

Answer 7

Active

Passive

Question 8

What is active immunity?

Answer 8

Uses the hosts own immune cells

Question 9

What is passive immunity?

Answer 9

Transfer of someone else’s immune cells

Question 10

Which of active and passive immunity creates immunological memory?

Answer 10

Active immunity

Question 11

What can active and passive immunity be further classified into?

Answer 11

Natural

Artificial

Question 12

Where are B cells produced?

Answer 12

Bone marrow

Question 13

What do B cells do on activation?

Answer 13

Differentiate into plasma cells

Question 14

What are plasma cells?

Answer 14

Responsible for antibody production

Question 15

Is it more important for B or T cells to be tolerant?

Answer 15

T cells because B cells need the help of T cells to make antibodies

Question 16

What happens to B cells that recognise self antigens?

Answer 16

Die in bone marrow by apoptosis

Question 17

What are epitopes?

Answer 17

Part of the antigen that antibodies bind to

Question 18

How can epitopes differ from each other, other than their structure and what they bind to?

Answer 18

Some induce larger immune responses than others

Question 19

What is an antigen?

Answer 19

Any substance capable of triggering an immune response

Question 20

What does the structure of an antibody consist of?

Answer 20

Variable region

Constant region

Question 21

What are the different antibody classes?

Answer 21

IgG

IgA

IgM

IgD

IgE

Question 22

What is IgG good for?

Answer 22

Good opsoniser

Question 23

What is IgA good for?

Answer 23

Protects mucosal surfaces, resistant to stomach acid

Question 24

What is IgM good for?

Answer 24

Fixing compliment and opsonisation

Question 25

What is IgD good for?

Answer 25

No known function

Question 26

What is IgE good for?

Answer 26

Defends against parasites, causing anaphylactic shock and allergies

Question 27

What is the antibody structure held by?

Answer 27

Disulphide bonds

Question 28

What are the two kinds of chains in the antibody structure?

Answer 28

Light chains

Heavy chains

Question 29

What receptor is in the heavy chains?

Answer 29

Fc

Question 30

What receptor is in the light chain?

Answer 30

Antigen binding region

Question 31

What are the 2 kinds of light chains?

Answer 31

Lamda

Kappa

Question 32

How many kinds of light chain are present in each antibody?

Answer 32

One, with both chains being identical

Question 33

What are the 2 regions of the heavy chain?

Answer 33

Constant region

Variable region

Question 34

What is the variable region?

Answer 34

Antigen binding site

Question 35

What are the 2 ways of activating an antibody?

Answer 35

T cell dependant

T cell independant

Question 36

What is used to activate antibodies without T cells?

Answer 36

Mitogen

Question 37

What is a mitogen?

Answer 37

Antigen with a very large number of repeated epitopes

Question 38

When do B cells produce antibodies?

Answer 38

When they are activated

Question 39

What is the first antibody that B cells produce?

Answer 39

IgM

Question 40

What does the class of the antibody depend on?

Answer 40

The constant region

Question 41

When is the compliment system activated by antibodies?

Answer 41

When they are bound to an antigen

Question 42

What are the 3 ways that antibodies eliminate pathogens by?

Answer 42

Neutralisation

Opsonisation

Compliment activation

Question 43

What does neutralisation do?

Answer 43

Discourages of prevents pathogens from initiating an infection

Question 44

What does opsonisation do?

Answer 44

Targets for phagocyte

Question 45

What happens to neutralised and opsonised complexes?

Answer 45

Phagocytoses by macrophages

Question 46

What is antibody dependant cytotoxicity (ADCC)?

Answer 46

The process of killing antibody coated target cells by leukocytes which have specific Fc receptors for these bound antibodies

Question 47

What is humoral immunity?

Answer 47

Aspect of immunity by the macromolecules found in extracellular fluid such as secreted antibodies and compliment proteins

Question 48

What is cell mediated immunity?

Answer 48

Immune response that does not involve antibodies, but the activation of phagocytes and antigen specific cytotoxic T cells with the release of various cytokines

Question 49

What is the process of B cell activation and class switching?

Answer 49

1) Antigen is recognised by BCR
2) B cell expresses MHCII and antigen complex on its surface
3) Gets recognised bt TCR of T_H2 cell
4) CD4 on B cell also binds to CD4L of T_H2 cell
5) T_H2 cell releases cytokines (IL2/4/5) which are recognised by ILR on B cell (interleukin receptor)
6) This determines the class switching of the B cell
7) B cell produces antibodies

Question 50

What determines the class switching of the B cell?

Answer 50

The cytokines released by the helper T cell

Question 51

What is the process of compliment mediated activation of B cell?

Answer 51

1) C3b is bound to a pathogen and degrades to C3d, C3df and iC3b
2) C3d reamins bound to pathogen and binds to a receptor on the surface of the B cell called CR2
3) Binding of CR2 and IgM greatly enhances the signals into the B cell so it is activated

Question 52

What receptor binds to C3d on a B cell?

Answer 52

CR2