Cell immunity

Question 1

BCR

Answer 1

B-cell receptor immunoglobulin

Question 2

TCR general structure

Answer 2

Similar structure to Aby with Vr and Cr regions, has two polypeptide chains connected via disulphide bridge which forms a single binding site

Question 3

MHC

Answer 3

major histocompatibility complex, TCRs can only recognize peptide antigens when presented on these

Question 4

TCR diversity

Answer 4

alpha and beta chains are fragmented and rearranged by RAG enzyme

Question 5

TCR alpha chain

Answer 5

analogous to the light chain with variable, joining and constant domain interchanged

Question 6

TCR beta chain

Answer 6

analogous to the heavy chain with variable, diversity, joining and constant domains interchanged

Question 7

Where are TCR chains assembled

Answer 7

Endoplasmic reticulum

Question 8

CD3 complex

Answer 8

2 epsilon (external)
1 delta (external)
1 gamma (external)
2 zeta (internal)
they are needed for transduction to membrane and intracellular signalling

Question 9

Gamma: delta TCR

Answer 9

alternate TCR formed mostly in fetal stage <5% might be involved in cancer friend vs foe

Question 10

TCR gamma chain

Answer 10

analogous to light chain with variable, joining and constant region

Question 11

TCR delta chain

Answer 11

Found within Alpha chain fragments it is analogous to heavy chain with variable, diversity, joining and constant regions

Question 12

CD4 T-cell

Answer 12

Helper T-cells bind to MHC 2 on professional antigen presenters (dendrites, macrophages, B-Cells)

Question 13

CD8 T-cell

Answer 13

Killer T-cell binds to MHC 1 on every cell in the body looking for pathogenic antigen

Question 14

What does CD stand for

Answer 14

Cluster of Differentiation

Question 15

CD8

Answer 15

Has an alpha and beta chain with long transmembrane legs connected via disulphide bond that stabilized the TCR:MHC1 interaction

Question 16

CD4

Answer 16

has one peptide chain with 4 domains and only one transmembrane leg, stabilized TCR:MHC2 interaction

Question 17

Classes of T-Helper

Answer 17

Differentiation occurs after activation by MHC2 and B7
Th1 activates macrophages
Th2 activates B-cells to become plasma cells and secrete Aby

Question 18

MHC 1

Answer 18

expressed on all nucleated cells
has a binding groove made from only one peptide chain

Question 19

MHC 2

Answer 19

only found on Ag presenting cells
-thymus epithelium
-B or T cells
-Professional APC
-Dendrites
-Macrophages
- B-Cells
Binding groove made of two peptide chains

Question 20

MHC Ag binding

Answer 20

MHC has degenerate peptide binding and can bind many different types of Ag

Question 21

Self tolerance

Answer 21

Immune cells ignore the self proteins offered by MHC 1 receptors when no pathogen Ag is present

Question 22

MHC class 1 Ag source

Answer 22

Proteasomes degrade internal proteins, transfered to MHC 1 by TAP transporter, sometimes self made but sometime virus made

Question 23

MHC class 2 Ag source

Answer 23

Professional APC take in extracellular pathogen into phagosome and break it down, then MHC 2 enters and takes AG to surface of cell

Question 24

CLIP

Answer 24

invariant chain fragment preventing pre mature binding of Ag to MHC 2, is removed by HLA-DM in the phagolysosome

Question 25

MHC isotypes

Answer 25

Do not rearrange during life time, just have allelic conversion once to make new isotype for a new person. extra diversity via genetic polymorphism

Question 26

MHC class 1 isoforms

Answer 26

A. -| B. | These are highly polymorph C. -| E - oligomorphic F - monomorphic G - oligomorphic

Question 27

MHC class 2 isoforms

Answer 27

DM-oligomorphic DO-oligo-monomorphic DP-polymorphic DQ-polymorphic DR- highly-oligomorphic

Question 28

MHC restriction

Answer 28

TCR binds only to antigen and MHC isoform that it recognizes

Question 29

antigen presentation

Answer 29

dendritic cells and macrophages travel through the lymph to secondary lymphoid tissues to present Ag to T-lymphocytes

Question 30

Leukocyte selectins (lectins)

Answer 30

leukocyte adhesion molecule to aid in homing to secondary lymphoid tissues

Question 31

vascular addressing (mucin-like_

Answer 31

leukocyte adhesion molecule to aid in homing to secondary lymphoid tissues

Question 32

Leukocyte integrin recetpros

Answer 32

leukocyte adhesion molecule to aid in homing to secondary lymphoid tissues

Question 33

ICAMs

Answer 33

inter-cellular adhesion molecules leukocyte adhesion molecule to aid in homing to secondary lymphoid tissues

Question 34

CD2

Answer 34

lymphocyte function assoc. leukocyte adhesion molecule to aid in homing to secondary lymphoid tissues

Question 35

CD B7

Answer 35

co-stimulatory interacts with CD28 on t-cells

Question 36

APC maturation

Answer 36

immature APC express innate immune receptors for microbial surface. once triggered it up regulates MHC 2 and B7 to trigger T-cells

Question 37

CD28

Answer 37

on T-cells it interacts with CD B7 to confirm that the antigen presented in a pathogen

Question 38

IL-2

Answer 38

interleukin 2 is produced by activated T-cells via B7 and CD 28 and IL-2 stimulates proliferation and differentiation

Question 39

Anergy

Answer 39

non-responsiveness in T-cells due to lack of B7 binding. That means the Ag bound is most likely a self protein and so the T-cell becomes unresponsive to that Ag

Question 40

CTLA4

Answer 40

another receptor on T-cells that binds B7 but with 20x more affinity than CD28. this receptor reduces proliferation and activation (slows immune system down)

Question 41

FAS ligand

Answer 41

Programs apoptosis and triggered by CD8 T-cells

Question 42

t-cell programmed death

Answer 42

FAS ligand and lytic granules (performs and granzymes)

Question 43

Autocrine T-cell activation

Answer 43

Occurs when CD8 t-cell binds to pathogen presenting MHC1 on dendritic cell. B7 is present too and therefore T-cell is activated, it produces it's own IL-2 and triggers Kill program

Question 44

Co-stimulatory T-cell activation

Answer 44

CD4 and CD8 bind to same inactivated APC, CD4 is presented pathogen Ag and activates cell to produce B7, CD8 cell now has B7 to be activated and kills

Question 45

Paracrine T-cell activation

Answer 45

Activated CD4 cell detects pathogen Ag and produces IL-2 into ECF, this activates CD8

Question 46

Apoptosis

Answer 46

programmed death that provides no inflamm response as it is clean and no inflamm soup is released