IIH L09-L12 B cell block

Question 1

How do TCRs recognise antigens? L09

Answer 1

Only short peptide sequences, only recognised on MHCs

Question 2

How do BCRs recognise antigens? L09

Answer 2

Whole antigen, plasma cells secrete antibodies/immunoglobulins to produce a soluble antigen receptor

Question 3

Where are MHC class I found? L09

Answer 3

All nucleated cells except neurones

Question 4

What type of protein do MHC class I recognise? L09

Answer 4

Endogenous

Question 5

What cells recognise MHC class I’s? L09

Answer 5

Cytotoxic T cells which express CD8 on their surface

Question 6

What does TAP protein do? L09

Answer 6

Controls peptides entering the endoplasmic reticulum, only in MHC I

Question 7

What are the two proteins that assist the folding of the MHC I? L09

Answer 7

Calnexin and calreticulin

Question 8

What protein retains a pool of MHC in the ER? L09

Answer 8

Tapasin; it binds MHC I to TAP

Question 9

Where are MHC class II found? L09

Answer 9

On antigen-presenting cells (DCs, macrophages, and B cells)

Question 10

What type of protein do MHC class II recognise? L09

Answer 10

Exogenous

Question 11

What cells recognise MHC class II’s? L09

Answer 11

T helper cells which express CD4 on their surface

Question 12

What protects the groove of MHC II from picking up peptides? L09

Answer 12

The invariant chain

Question 13

What catalyses the antigenic peptide being inserted into the groove of MHC II? L09

Answer 13

HLA-DM

Question 14

What are fully developed B cells called? L09

Answer 14

Plasma cells

Question 15

What is an example of a signalling molecule found on the surface of a B cell? L09

Answer 15

CD19, CD79, CD21

Question 16

What is the TCR composed of? L09

Answer 16

Two non-identical Ig-domain polypeptide chains

Question 17

What is the name of the signalling molecule and TCR complex? L09

Answer 17

CD3 complex

Question 18

What is somatic recombination? L09

Answer 18

Unique mechanism of genetic recombination that results in a highly diverse range of immunoglobulins and TCRs

Question 19

What are the names of the four gene segments that make up the genes for immunoglobulins? L09

Answer 19

Variable (V)
Diversity (D)
Joining (J)
Constant (C)

Question 20

What are the two enzymes required for somatic recombination? L09

Answer 20

RAG-1 and RAG-2

Question 21

Which region of the immunoglobulin is affected by somatic hypermutation? L09

Answer 21

Variable region; how you develop high affinity antibodies to antigen in germinal centres

Question 22

Which region of the immunoglobulin is affected by class switching? L09

Answer 22

Constant region; different classes of immunoglobulin have different effector functions, so a change allows different effector actions against the same antigen

Question 23

What is an antigen? L10

Answer 23

Molecules that induce an immune response through the activation of antigen specific B/T cells

Question 24

What is an epitope? L10

Answer 24

The molecular structure recognised by the binding site of an antibody or TCR

Question 25

What are the five classes of Ig? L10

Answer 25

M, A, G, D, E

Question 26

Which immunoglobulin can pass through the placenta? L10

Answer 26

IgG

Question 27

Which immunoglobulin is pentameric? L10

Answer 27

IgM

Question 28

Which immunoglobulin mediates type I hypersensitivity? L10

Answer 28

IgE

Question 29

Which immunoglobulin is in breast milk? L10

Answer 29

IgA

Question 30

In the spleen, how do lymphocytes enter the secondary lymphoid tissue? L12

Answer 30

Through the walls of the marginal zone blood sinusoids

Question 31

In tissues (excluding the spleen), how do lymphocytes enter the secondary lymphoid tissue? L12

Answer 31

Through high endothelial venules (afferent lymphatics)

Question 32

How do lymphocytes leave the spleen if they do not encounter an antigen? L12

Answer 32

Through the red-pulp blood sinusoids

Question 33

How do lymphocytes leave the tissues (excluding spleen) if they do not encounter an antigen? L12

Answer 33

Through efferent lymphatics

Question 34

Where do B cells migrate to in secondary lymphoid tissue? L12

Answer 34

Follicles

Question 35

What is T-cell priming? L12

Answer 35

Antigen-specific activation of naive CD4+ T helper cells at the surface of dendritic cells

Question 36

Where do B-blasts differentiate into antibody-secreting plasma cells? L12

Answer 36

Medullary cords

Question 37

What type of antibodies are produced in germinal centres? L12

Answer 37

High affinity, class switched antibodies (IgM to IgA/IgG)

Question 38

What is affinity maturation? L12

Answer 38

Process by which B cells produce antibodies with increased affinity for antigen during the course of an immune response

Question 39

What is an MHC I molecule made up of? L09

Answer 39

3 alpha subunits (expressed on chromosome 6), and 1 beta microglobulin subunit (expressed on chromosome 15)

Question 40

What is an MHC II molecule made up of? L09

Answer 40

2 alpha subunits and 2 beta subunits (all expressed on chromosome 6)

Question 41

State the lengths of peptide that normally bind MHC I?

Answer 41

8-10 residues

Question 42

State the lengths of peptide that normally bind MHC II?

Answer 42

15-25 residues

Question 43

Two examples of how NK cells can recognise virally infected cells?

Answer 43

CD16 (= FcγRIII) | ADCC

Question 44

Cytokine that is released from somatic cells and limits the spread of the virus?

Answer 44

IFNalpha

Question 45

Two cytokines that Th1 CD4+ T cells secrete to stimuate macrophages to clear their intracellular pathogens?

Answer 45

IFNγ | TNFα

Question 46

Name three intracellular bacterial pathogens.

Answer 46

Mycobacteria Salmonella Listeria

Question 47

How many antibodies can one B cell produce?

Answer 47

10^5