T cells

Question 1

T lymphocyte involved in effector function

Answer 1

cytotoxic T lymphocytes (Tc)

Question 2

T lymphocyte involved in regulatory immune function

Answer 2

Helper T cells (Th cells)

Question 3

How T cells react with antigen

Answer 3

T cell Receptor (TcR) - present on T cell membrane surface, derived from bone marrow

Question 4

CD4+

• expressed by what cell
• interacts with which MHC
• binds with which region of MHC

Answer 4

• coreceptor on Th cells
• MHCII
• beta 2 domain of MHCII

Question 5

CD3

• expressed by which cells
• important

Answer 5

both Tc and Th cells

important for clonal expansion

Question 6

How B cells react with antigen

Answer 6

immunoglobulins

Question 7

TcR look structurally similar to

Answer 7

FAB region on antibody where antigen binds

Question 8

Two major types of CD4+

Answer 8

Th1, Th2

Question 9

This specific type of cell modulates phagocytic cell and inflammatory reactions

Answer 9

Th1

Question 10

This specific type of cell produce factors that help stimulate B cells to differentiate into plasma cells

Answer 10

Th2

Question 11

TcR recognize what complex

Answer 11

MHCII with a bound processed peptidal antigen on an APC

Question 12

Rearrangement of T cell receptors occur at this site

Answer 12

Thymus (arise in bone marrow, mature in thymus)

Question 13

Which step of rearrangement/mode of diversity is NOT present in T cells?

Answer 13

Somatic hypermutation - only in B cells

Question 14

TcR structure. Which part is equivalent to the heavy chain?

Answer 14

Valpha Vbeta
Calpha Cbeta

beta is like heavy chain

Question 15

Which part of TcR structure will undergo rearrangement first?

Answer 15

Variable beta chain rearranges first, then produces alpha chain which will undergo VJ rearrangement like light chain

Question 16

What is the signal that induces Th cell to become a Th1 cell?

Answer 16

IL-12 released from professional APC

Question 17

Signature cytokine of Th1

Answer 17

interferon gama

Question 18

After Th cell binds to profession APC, explain in 3 steps how it matures to Th1 cell

Answer 18

professional APC releases IL-12
induces Th to become Th1 cell
Th1 will release interferon gamma

Question 19

Function of interferon gamma

Answer 19

professional APC (like macrophages) increase production of oxidative species = BETTER KILLER

Question 20

Important property of interferon gamma

Answer 20

class switch factor. tells B cells to produce IgG for opsonization

Question 21

When would you develop a Th1?

Answer 21

To produce IgG when macrophage wants to opsonize

Question 22

Explain in 3 steps how Th2 cell develops

Answer 22

1. Macrophage does NOT release IL-12
2. Th cell will produce IL-4, feeds back on to itself
3. Converts Th cell to Th2

Question 23

IL-4

Answer 23

Th2

Question 24

Il-12

Answer 24

Th1

Question 25

Il-4 is a class switch factor for

Answer 25

IgE

Question 26

Why would you develop Th2?

Answer 26

To produce IgE, might be more important for parasitic infection, wont ingest it to destroy it

Question 27

receptor for HIV

Answer 27

CD4+

Question 28

Marker expressed on Tc cells

Answer 28

CD8+

Question 29

CD8+ - expressed by what cell - interacts with which MHC - binds with which region of MHC

Answer 29

- Tc cel - MHCI - alpha 3

Question 30

A second receptor on T cells encoded from distinct family of genes but with structurally similar polypeptide chains

Answer 30

gamma and delta

Question 31

When does Tcell activation occur?

Answer 31

When TcR of T cell has engaged processed antigen in context of an MHC on APC

Question 32

Birthplace of T cells

Answer 32

bone marrow

Question 33

thymocyte

Answer 33

maturing T cell in thymus

Question 34

Maturation steps of Thymus

Answer 34

DN>DP>SP>PS>NS

Question 35

Enters thymus as double negative through which region of thymus?

Answer 35

Cortical region

Question 36

Double negative

Answer 36

CD4- CD8- TcR- CD3-

Question 37

T cells undergo beta and alpha chain rearrangement in this region

Answer 37

cortical region (first step)

Question 38

Transitions from double negative to double positive in this region

Answer 38

From cortical region on way to cortico-medullary junction

Question 39

This part of TcR undergoes VDJ rearrangement

Answer 39

beta genes

Question 40

Once beta chain is complete, a small portion migrates to cell membrane via this structure to trigger allelic exclusion

Answer 40

Surrogate alpha chain

Question 41

This part of TcR undergoes VJ rearrangement

Answer 41

alpha gene

Question 42

T cells reacts with these to become single positive

Answer 42

MHCI and MHCII

Question 43

MHC in thymus react with

Answer 43

SELF MADE antigens

Question 44

Presents peptides from all over by inducing tissue specific genes

Answer 44

Auto immune regulator element (AIRE)

Question 45

After surviving positive and negative selection, T cells leave through this region of thymus

Answer 45

Medulla

Question 46

Fate for cells that don't pass the selection tests in thymus or see antigen

Answer 46

apoptosis

Question 47

Percentage of T cells that survive the selection test in thymus

Answer 47

5%

Question 48

These cells exress MHCI and II for purpose of single positive

Answer 48

Thymic epithelial cells

Question 49

This part of selection ensures Tcell wont engage its own MHC once released

Answer 49

negative selection

Question 50

process becoming either a CD4+ OR a CD8+ based on interaction with specific MHC

Answer 50

positive selection

Question 51

This enzyme is not present in T cells so that hypermutation does not occur

Answer 51

AID (activation induced cytodine deaminase)

Question 52

Occurs by genetic recombination of constant (C) gene segments to synthesize Ig isotypes

Answer 52

Ig class switching

Question 53

Occurs by genetic recombination of constant (C) gene segments to synthesize Ig isotypes

Answer 53

Ig class switching