Foundations in Immunology 3 Flashcards Preview

Science for Medicine > Foundations in Immunology 3 > Flashcards

Flashcards in Foundations in Immunology 3 Deck (52):
1

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

Very specific

Immunological memory

2

What antigen do B cells use to recognise free antigens?

BCR (surface IgM)

3

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

MHC

4

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

With much higher affinity

5

What is a naive B cell?

B cell that has not been exposed to an antigen

6

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

Becomes a memory B cell or a plasma cell

7

What are the 2 kinds of adaptive immunity?

Active 

Passive

8

What is active immunity?

Uses the hosts own immune cells

9

What is passive immunity?

Transfer of someone else's immune cells

10

Which of active and passive immunity creates immunological memory?

Active immunity

11

What can active and passive immunity be further classified into?

Natural

Artificial

12

Where are B cells produced?

Bone marrow

13

What do B cells do on activation?

Differentiate into plasma cells

14

What are plasma cells?

Responsible for antibody production

15

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

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

16

What happens to B cells that recognise self antigens?

Die in bone marrow by apoptosis

17

What are epitopes?

Part of the antigen that antibodies bind to

18

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

Some induce larger immune responses than others

19

What is an antigen?

Any substance capable of triggering an immune response

20

What does the structure of an antibody consist of?

Variable region

Constant region

21

What are the different antibody classes?

IgG

IgA

IgM

IgD

IgE

22

What is IgG good for?

Good opsoniser

23

What is IgA good for?

Protects mucosal surfaces, resistant to stomach acid

24

What is IgM good for?

Fixing compliment and opsonisation

25

What is IgD good for?

No known function

26

What is IgE good for?

Defends against parasites, causing anaphylactic shock and allergies

27

What is the antibody structure held by?

Disulphide bonds

28

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

Light chains

Heavy chains

29

What receptor is in the heavy chains?

Fc

30

What receptor is in the light chain?

Antigen binding region

31

What are the 2 kinds of light chains?

Lamda

Kappa

32

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

One, with both chains being identical

33

What are the 2 regions of the heavy chain?

Constant region

Variable region

34

What is the variable region?

Antigen binding site

35

What are the 2 ways of activating an antibody?

T cell dependant

T cell independant

36

What is used to activate antibodies without T cells?

Mitogen

37

What is a mitogen?

Antigen with a very large number of repeated epitopes

38

When do B cells produce antibodies?

When they are activated

39

What is the first antibody that B cells produce?

IgM

40

What does the class of the antibody depend on?

The constant region

41

When is the compliment system activated by antibodies?

When they are bound to an antigen

42

What are the 3 ways that antibodies eliminate pathogens by?

Neutralisation

Opsonisation

Compliment activation

43

What does neutralisation do?

Discourages of prevents pathogens from initiating an infection

44

What does opsonisation do?

Targets for phagocyte

45

What happens to neutralised and opsonised complexes?

Phagocytoses by macrophages

46

What is antibody dependant cytotoxicity (ADCC)?

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

47

What is humoral immunity?

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

48

What is cell mediated immunity?

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

49

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

1) Antigen is recognised by BCR

2) B cell expresses MHCII and antigen complex on its surface

3) Gets recognised bt TCR of TH2 cell

4) CD4 on B cell also binds to CD4L of TH2 cell

5) TH2 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

50

What determines the class switching of the B cell?

The cytokines released by the helper T cell

51

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

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

52

What receptor binds to C3d on a B cell?

CR2