Helper T Cells.

Question 1

What 2 immune cells are helped by T helper cells?

Answer 1

B cells.

Cytotoxic T cells.

Question 2

When can naive T cells be activated?

Answer 2

When they are presented an antigen by a dendritic cell.

Question 3

What tissues will naive T helper cells always be activated in?

Answer 3

The secondary lymphoid organs.

Question 4

What is a naive T cell?

Answer 4

A mature lymphocyte that has not interacted with its antigen.

Question 5

When will a T cell go from naive to activated?

Answer 5

When it is presented with its antigen.

Question 6

What cells can helper T cells present antigens to?

Answer 6

Cytotoxic T cells.

B cells.

Question 7

When can a T cell interact with other immune cells?

Answer 7

After it has seen an antigen.

Question 8

Can helper T cells interact with APCs?

Answer 8

Yes.

Question 9

Why can helper T cells interact with multiple APCs?

Answer 9

Because T cells have so many receptors on their cell surface.

Question 10

What happens once a naive T cells TCR has bound to an antigen?

Answer 10

The T cell proliferates and differentiates.

Question 11

Why do B cells and cytotoxic T cells need help from T cells?

Answer 11

As they cannot have a good response without help from T helper cells.

Question 12

What are the 2 main types of T helper cells?

Answer 12

TH1 and TH2 cells.

Question 13

What is a TH-0 cell?

Answer 13

A naive T cell in the lymph node.

Question 14

What are the 4 cell types that can be formed once a naive T cell has been presented with an antigen?

Answer 14

TH-1.

TH-2.

TH-17.

T-REG.

Question 15

What dictates what type of helper T cell is formed following antigen presentation?

Answer 15

The cytokines that are present.

Question 16

What are T-REGs?

Answer 16

T-regulatory cells which are anti inflammatory and shut down immune responses.

Question 17

What do T-REG cells help to regulate?

Answer 17

Autoimmunity.

Question 18

What is the major function of T-REG cells?

Answer 18

To end immune responses when a disease has been cured.

Question 19

What are the most potent inflammatory cells and can cause a lot of autoimmune reactions?

Answer 19

TH-17 cells.

Question 20

What form of immunity are TH-1 cells associated with?

Answer 20

Cell mediated immunity.

Question 21

Why are TH-1 cells often called pro-inflammatory T helper cells?

Answer 21

As the cytokines they secrete activate macrophages.

Question 22

What form of immunity are TH-2 cells associated with?

Answer 22

Humoral immunity.

Question 23

What is the major role of TH-2 cells?

Answer 23

They help B cells produce the correct antibodies to fight extracellular pathogens.

Question 24

Do TH-1 and TH-2 cell function at the same time?

Answer 24

No, they are antagonistic.

Question 25

What is the function of IL-2 in T cell differentiation?

Answer 25

It helps T helper cells to go from undifferentiated T helper cells to a TH-1 cell.

Question 26

What T helper cells are involved in cell mediated immunity?

Answer 26

TH-1 cells.

Question 27

What T helper cells secrete IL-2?

Answer 27

TH-1 cells.

Question 28

How does IL-2 affect T cell activation?

Answer 28

It leads to the proliferation of all T cells.

Question 29

Why do TH-1 cells secrete interferon gamma?

Answer 29

As interferon gamma activates macrophages.

Question 30

What interleukin is responsible for causing undifferentiated T helper cells to from TH-2 cells?

Answer 30

IL-4.

Question 31

What 2 interleukins are secreted by activated TH-2 cells?

Answer 31

IL-4 and IL-5.

Question 32

What is the function of IL-4?

Answer 32

It helps TH-2 cells communicate with B cells.

Question 33

What is the function of IL-5?

Answer 33

It activates eosinophils.

Question 34

If TH-1 cells are active, will there be many TH-2 cells active?

Answer 34

No, and vice versa.

Question 35

What are the 2 cytokines associated with TH-1 cells?

Answer 35

IL-2. Interferon gamma.

Question 36

What is the function of interferon gamma?

Answer 36

It activates macrophages.

Question 37

What is the function of IL-2?

Answer 37

It activates T cells, B cells and NK cells.

Question 38

What cytokines are secreted by TH-2 cells?

Answer 38

IL-4. IL-5.

Question 39

What is the function of IL-4?

Answer 39

It stimulates B cell proliferation and helps to neutralise antibody production.

Question 40

What is the best neutralising antibody?

Answer 40

IGG.

Question 41

How does IGG function as a neutralising antibody?

Answer 41

It binds to a microbe and prevents it from performing its function.

Question 42

What is the function of IL-5?

Answer 42

It helps with B cell responses and activates eosinophils.

Question 43

What CD molecules are always found on T helper cells?

Answer 43

CD-4.

Question 44

What happens when naive T cells differentiate into TH-1 cells?

Answer 44

They produce interferon gamma to activate macrophages.

Question 45

What innate immune cell is activated when TH-1 cells are formed?

Answer 45

Macrophages.

Question 46

What innate immune cell is activated when TH-2 cells are formed?

Answer 46

They produce IL-4 and IL-5.

Question 47

What is the function of immune profiling?

Answer 47

To differentiate between TH-1 and TH-2 cells.

Question 48

How do we perform immune profiling?

Answer 48

We stain to differentiate interferon gamma and IL-4. TH-1 are interferon gamma positive and IL-4 negative. TH-2 cells are interferon gamma negative and IL-4 positive.

Question 49

Why do we perform immune profiling?

Answer 49

To know whether a pathogen is mediated by TH-1 or TH-2 cells.

Question 50

Why is it important to know whether a pathogen is mediated by TH-1 or TH-2 cells?

Answer 50

It helps us understand whether the pathogen initiates a cell mediated response or a humoral response. This allows us to tailor drugs to the pathogen.

Question 51

What is the role of cytotoxic T cells?

Answer 51

To recognise and kill virally infected cells, tumour cells and MHC incompatible cells.

Question 52

What must cells display on their MHC-1 if they are to be killed by an NK cell?

Answer 52

An endogenous foreign antigen. A tumour antigen. A foreign MHC.

Question 53

How do T helper cells interact with B cells?

Answer 53

T helper cells help to activate B cells.

Question 54

Why do TH-2 cells secrete IL-4?

Answer 54

It helps a B cell differentiate into a plasma cell.

Question 55

What T cells tend to dictate adaptive immunity?

Answer 55

CD4+ T cells.