CHP 4 - Adaptive Immune System

Question 1

Which receptor on the T cell is responsible for recognizing pathogens?

Answer 1

T-cell Receptors

Question 2

T/F: T-cell receptors are transmembrane proteins

Answer 2

True

Question 3

T-cell receptors are heterodimers and can consist which chains?

Answer 3

1) alpha and beta
2) gamma and delta

Question 4

In order to T-cell receptors for recognize antigen, they must attached to which molecule? – a receptor found on other cells

Answer 4

MHC molecule

Question 5

MHC I binds/interacts with which T-cell substype?

Answer 5

CD8+

Question 6

MHC II binds/interacts with which T-cell subtype?

Answer 6

CD4+

Question 7

MCH I can be found on which cells?

Answer 7

All nucleated cells

Question 8

MHC II can be found on which cells?

Answer 8

Antigen presenting cells ( immune cells)

Question 9

Elaborate which cells of the innate immune system will have MHC II?

Answer 9

1) Macrophages
2) Neutrophils
3) Dendritic cells

Question 10

MHC I presents peptides that have been degraded from _______ the cell

Answer 10

Inside

Question 11

MHC II presents peptides that have been degraded from _______ the cell

Answer 11

Outside

Question 12

CD8 + T cells express a receptor that recognizes antigen presented by which MHC class molecule?

Answer 12

MHC I

Question 13

CD4 + T cells express a receptor that recognizes antigen presented by which MHC class molecule?

Answer 13

MHC II

Question 14

CD8 coreceptor binds to the ____ chain of the MHC class I

Answer 14

alpha

Question 15

CD4 coreceptor binds to the ____ chain of the MHC II class molecule

Answer 15

Beta chain

Question 16

What is the basic immunoglobulin structure?

Answer 16

2 heavy chains, 2 light chains held by disulfide linkages

Question 17

T/F: immunoglobulins have 2 identical binding sites?

Answer 17

True

Question 18

Which region of immunoglobulins is responsible for forming a single antigen binding site?

Answer 18

Variable region of the heavy chains and light chains

Question 19

What are the five major functions of soluble immunoglobulins?

Answer 19

1) Neutralization of foreign particles or pathogens
2) Opsonization – increases phagocytosis
3) Complement activation – classical pathway activation of complement system
4) Activation of innate immune cells – due to phagocytosis and complement system enhancement
5) Protection of internal mucosal surfaces

Question 20

Why does the adaptive immune system require several days to two weeks to respond to new pathogen?

Answer 20

1) Receptor diversity – somatic recombination
2) Antigen presentation and migration
3) Proliferation and differentiation of antigen specific B cells and T cells

Question 21

CD8 T cells engage with class _____ MHC and differentiate into ____________.

Answer 21

I ; cytotoxic

Question 22

CD4 T cells engage with class ___ MHC and differentiate into _____________.

Answer 22

II ; Helper T cells

Question 23

What is the function of a Helper T cell?

Answer 23

Stimulate B cells to proliferate and differentiate into memory B cells and plasma B cells

Question 24

Somatic recombination only occurs in __________ T cells and B cells

Answer 24

Developing

Question 25

Which segments during somatic recombination are spliced and recombined in the alpha T cell receptor and light chains of an immunoglobulin?

Answer 25

V and J

Question 26

Which segments during somatic recombination are spliced and recombined in the beta chain of a T cell receptor and heavy chains of an immunoglobulin?

Answer 26

V, D, and J

Question 27

What are the two different types of light chains in immunoglobuolins?

Answer 27

K (Kabba) and Lamda

Question 28

Heavy chain of an immunoglobulin has which recombination segments?

Answer 28

V, D, and J

Question 29

The light chains of an immunoglobulin has which recombination segments?

Answer 29

V and J

Question 30

T/F: Each B cell can express immunoglobulin with different light chains (Kabba and Lamda)

Answer 30

False; must be the same light chain Kabba and Kabba or Lamda and Lamda

Question 31

Recombination of lymphocyte genes requires the action of VDJ recombinase through ________ enzyme which recognizes _______ at different gene segments

Answer 31

RAG; RSSs

Question 32

How does diversity occur at the joints? (after RAG1/RAG2 cleave VDJ segments?

Answer 32

1) addition of P-nucleotides in single strand overhangs 2) Deletion of nucleotides 3) Addition of random nucleotides called N-nucleotides 4) Junctional sequence diversity amplifies receptor diversity

Question 33

Which enzyme is responsible for adding P-nucleotides on single strand overhangs?

Answer 33

Artemis

Question 34

Which enzyme is responsible for deleting nucleotides?

Answer 34

Exonuclease

Question 35

Which enzyme is responsible for the addition of random nucleotides called N-nucleotides?

Answer 35

(TdT) Terminal deoxynucleotydil transfersase

Question 36

What mechanisms result in T cell and B cell receptor diversity?

Answer 36

T cell and B cells 1) Multiple gene segments - V(D)J 2) Templated nucleotide addition (P-nucleotide addition) 3) Deletion of nucleotides - exonuclease trimming 4) Non templated nucleotide addition (N-nucleotides) ONLY B cells Combination diversity of light chains with heavy chains

Question 37

Which self tolerance mechanism is responsible for selecting cells with functional receptors?

Answer 37

Positive selection

Question 38

Which self tolerance mechanisms is responsible for terminating cells with high affinity to self-receptors?

Answer 38

Negative selection

Question 39

When a lymphocyte lacks membrane receptors that recognize antigen it dies by ?

Answer 39

Neglect

Question 40

Lymphocytes with functioning MHC receptors are ___________ selected to continue their development

Answer 40

Positively

Question 41

Lymphocytes that are too likely to recognize self-antigen are ____________ selected and die by apoptosis

Answer 41

Negatively

Question 42

To prevent circulation of self-reactive lymphocytes, receptors are tested for binding affinity to self-antigen. This type of selectivity is also known as?

Answer 42

Negative selection

Question 43

Developing lymphocytes are tested for their presence and binding capacity of their receptor. This type of selectivity is known as?

Answer 43

Positive selection

Question 44

What are the steps of MHC class I peptide presention?

Answer 44

1) proteins in cytoplasm digested to peptide fragments via proteasome 2) transportation of peptide fragments to ER and loaded to MHC I 3) Class I MHC peptide complex exits ER and travels to plasma membrane 4) Recognition of MHC I peptide complex from CD8 T cell

Question 45

How does MHC I peptide complex travel to the plasma membrane?

Answer 45

Through secretion pathway via vesicles to the Golgi complex and eventually to the plasma membrane

Question 46

What are the steps of MHC II peptide complex presentation?

Answer 46

1) Synthesis of MHC II molecule at ER - inactive state 2) Transportation of inactive MHC II molecule to Golgi complex through secretory pathway via vesicles and wait for fusion with phagolysosome 3) Recognition of extracellular pathogen and phagocytosis 4) Fusion of phagolysosome and vesicle containing MHC II molecule -- now active 5) transportation of MHC II peptide complex to plasma membrane 6) CD4 T cell recognition

Question 47

T cell receptors associate with other transmembrane proteins that form the _____

Answer 47

CD3 complex

Question 48

What do naive B cells initially secrete? (type of immunoglobulin)

Answer 48

IgM

Question 49

Naive B cells have cell which subtype of immunoglobulins on its cell surface?

Answer 49

IgM and IgD

Question 50

Give reasons as to why the primary immune response requires time

Answer 50

1) antigen recognition and processing 2) migration of dendritic cells to lymph nodes 3) T cell presentation 4) activation and differentiation of T cells and B cells

Question 51

What needs to occur for the CD3 complex of a T cell receptor to change structure and send signaling motifs?

Answer 51

Phosphorylation

Question 52

All CD8 T cell's become into cytotoxic T cells when exposed to an antigen. However, CD4 can become into other T cells. What are these effector T cells?

Answer 52

1) NK T cells 2) TH2 - Helper T cell 3) Th17 - activates neutrophils 4) Memory T cells 5) Regulatory T cells -- induces tolerance

Question 53

Which proteins are associated with B cell receptors and have cytoplasmic domains with signaling motifs?

Answer 53

Ig-alpha and ig-beta

Question 54

Ig-alpha and Ig-beta signals B cells to?

Answer 54

differentiate into antibody secreting cells (plasma cells)