t cell activation

Question 1

what are the requirements for t cell activation?

Answer 1

Antigen presented as peptides
by APCs using MHC molecules
Co-stimulators on the APCs
Cytokines

Question 2

what are co- stimulators

Answer 2

APCs express molecules that are required for t cell activation in addition to the antigen

Question 3

what are co stimulators (2)

Answer 3

Co-stimulators are important molecules that help activate our immune system

Question 4

what happens when you have an activated APC

Answer 4

increased expression of co stimulators and secretion of cytokines

Question 5

what are b7 co stimulautors?

Answer 5

molecules found on immune cells that play a crucial role in activating T cells.

Question 6

what do t helpers do?

Answer 6

T helper cells
co-ordinate the immune response

Question 7

what does a non specifc defense lead to?

Answer 7

macrophage/ neutrophil activation/ leukocyte migration

Question 8

what does humoral immunity lead to?

Answer 8

activation of B cells

Question 9

what does cellular immunity lead to?

Answer 9

activation of t cytoxic cells

Question 10

what is the role of naiive t cells

Answer 10

Naïve T cells differentiate into different types of T helper cells

Question 11

what is naive t cells dependant on?

Answer 11

is dependent on the type of cytokine secreted by the APC also dependant on what other cells are there as well

Question 12

what does Pro-inflammatory macrophages give rise to?

Answer 12

Tissue damage

Question 13

what does Anti-inflammatory macrophages give rise to?

Answer 13

Tissue repair

Question 14

what does the TREG cell do? 1/2

Answer 14

Immunosuppression by binding to B7 molecules on APCs

Question 15

what does the TREG cell do? 2/2

Answer 15

inhibit activation of neutrophils
- promotes angiogenesis

Question 16

summarise Cytotoxic T cell activation

Answer 16

APCs are usually dendritic cells
Antigens need to be presented on MHC I molecules
T helper cells aid in CTLs activation in 2 ways

Question 17

T helper cells aid in CTLs activation in 2 ways.

what ways do they help?

Answer 17

T helper cells secrete IL-2 which helps to activate naïve CTLs cells
T cells enhance the ability of APCs to stimulate CTLs cells

Question 18

what are CTLs cells?

Answer 18

identifying and destroying cells infected with pathogen

Question 19

what are the steps in Cytotoxic T cell activation

Answer 19

antigen recognition
lymphocyte activation
clonal expansion
differentiation
effector functions

Question 20

what are the 2 major types of MHC protein molecules?

Answer 20

Class I MHC molecules
Class II MHC molecules

Question 21

what is a Class II MHC molecules

Answer 21

are restricted to cells of theimmune system- macrophages, dendritic cells and B cells

Question 22

what is a Class I MHC molecules

Answer 22

present on everynucleated cellin an organisms

Question 23

where are CLASS 1 MHC molecules located?

Answer 23

MHCI molecules present peptides to T Cytotoxic cells

Question 24

where are CLASS 2 MHC molecules located?

Answer 24

MHCII molecules present peptides to T Helper cells

Question 25

what do cytotoxic t cells also produce?

Answer 25

Cytotoxic T cells also produce INF-γ (aids in activation of macrophages)

Question 26

describe memory t cells?

Answer 26

Specific for the antigen Persist for years/lifetime Respond more rapidly to specific antigen stimulation than naïve cells

Question 27

what TCR also known as?

Answer 27

T cell receptors

Question 28

each t cell has what?

Answer 28

number of TCRs (of a single specificity)

Question 29

what cell is only required in antigen recoginstion?

Answer 29

Only the TCR

Question 30

what is intergrin needed for?

Answer 30

adhesion

Question 31

what is CD28, CD3, CD4, CD8 needed for?

Answer 31

signal transduction.

Question 32

what is the structure like in a TCR ?

Answer 32

can bind only one antigen recognise antigens displayed as short peptides

Question 33

What are the main types of APCs

Answer 33

dendritic cells, macrophages, and B cells

Question 34

what can TCRs recongise?

Answer 34

antigens displayed as short peptides on MHC molecules

Question 35

t helper cells TCR recognise what?

Answer 35

recognise antigens displayed on MHC II molecules

Question 36

t cytotoxic cell TCR recognise what?

Answer 36

recognise antigens displayed on MHC I molecules

Question 37

what cells do t helper cells recognise?

Answer 37

CD4+ cells

Question 38

what do t cytoxic cells recongise?

Answer 38

CD8+

Question 39

CD4+ and CD8+ aid in what?

Answer 39

initiating signalling pathways within the cell

Question 40

binding of antigen to a tcr results in what?

Answer 40

activates a number of signalling pathways in the cell which results in its differentiation, proliferation activation of other effector activities