T cell mediated immunity

Question 1

Mature circulating T cells that have not yet encountered their specific antigens are known as:

Answer 1

Naive T cells

Question 2

A naive T cell that meets its specific antigen, presented to it as a peptide:MHC complex on the surface of an APC, is induced to:

Answer 2

proliferate and differentiate into effector T cells

Question 3

All effector T cells act on other …. cells, because they require antigens to be presented on …

Answer 3

Host, MHC

Question 4

CD8 T cells recognise pathogen presented on

Answer 4

MHC class 1 molecules

Question 5

Naive CD8 T cells differentiate into ……… T cells that recognise and kill ………. cells

Answer 5

cytotoxic, infected

Question 6

CD4 T cells recognise pathogen presented on … ….. .

Answer 6

MHC class II

Question 7

The main CD4 effector subsets are:

Answer 7

Th1, Th2, Th17

Question 8

The primary function in the adaptive immune response of Th17 CD4 effector T cells is:

Answer 8

To enhance neutrophil response

Question 9

The two main functions of Th1 CD4 effector T cells in the adaptive immune response is:

Answer 9

1. To activate infected macrophages

2. Assist B cells with antibody production

Question 10

The two main functions of Th2 CD4 effector T cells in the adaptive immune response is:

Answer 10

1. Assist B cells with antibody production

2. Assist B cells with switching to IgE

Question 11

The main function of CD8 cytotoxic T cells is:

Answer 11

To kill virus infected cells

Question 12

The pathogens targeted by CD8 cytotoxic T cells are:

Answer 12

1. Viruses

2. Some intracellular bacteria

Question 13

The pathogens targeted by CD4 Th1 cells are:

Answer 13

1. Microbes that persist in macrophage vesicles (e.g. mycobacteria, Listeria, Leishmania, pneumocystis)
2. Extracellular bacteria

Question 14

The pathogens targeted by CD4 Th2 cells are:

Answer 14

Helminths

Question 15

The pathogens targeted by CD4 Th17 cells are:

Answer 15

Extracellular bacteria

Question 16

The general role of CD4 regulatory T cells (various types) is to:

Answer 16

Suppress T cell responses

Question 17

The activation of naive T cells in response to antigen, and their subsequent proliferation and differentiation into effector cells, constitutes a ……. ….-…….. …… ………

Answer 17

primary cell-mediated immune response

Question 18

The two major components of cell mediated immunity stimulated by effector T cells are:

Answer 18

1. Macrophage activation
2. Cytotoxicity
   (also stimulate B cell antibody production - non cell mediated immunity)

Question 19

What type of T cell is generated in addition to effector T cells as part of the primary T cell response?

Answer 19

Memory T cells

Question 20

The activation and clonal expansion of a naive T cell is often called: ……. . Why?

Answer 20

Priming; to distinguish it from the responses of effector T cells to antigen on their target cells and the responses of primed memory Tcells

Question 21

In the activation of naive T cells, signal 1 is:

Answer 21

Antigen specific activation of the T cell receptor

Question 22

In the activation of naive T cells, signal 2 is:

Answer 22

Interaction of costimulatory molecules on APCs with ligands on the T cells

Question 23

In the activation of naive T cells, signal 3 is:

Answer 23

Cytokines that control differentiation into different types of effector cells

Question 24

What sets in motion the 3 signals for activation of naive T cells?

Answer 24

Much earlier signals arising from the intial detection of the pathogens by the innate immune system

Question 25

Give an example of a receptor of the innate immune system

Answer 25

TLRs

Question 26

What pattern do TLR and other similar receptors recognise? Why is this essential?

Answer 26

They recognise pathogen associated molecular patterns that signify the presence of non-self. These signals are essential to activate APCs so that they can activate naive T cells

Question 27

What is the most important APC?

Answer 27

The dendritic cell

Question 28

What is the function of a dendritic cell?

Answer 28

To ingest and present antigen

Question 29

Are DCs part of the innate or adaptive immune response?

Answer 29

DCs detect antigen at sites of infection and are activated as part of the innate immune response

Question 30

When a DC is activated, what does it do?

Answer 30

Activated DCs migrate to local lymphoid tissue and mature into cells that are effective APCs for recirculating naive T cells.