Adaptive B Cells And T Cells

Question 1

What disease can inflammation cause?

Answer 1

Type 2 diabetes
Alzheimer’s
Chronic disease
Hepatitis and liver cancer
CVD

Question 2

What is the main function of B-cells?

Answer 2

Make antibodies - but they require help from T-cells

Question 3

What is the main function of T cells?

Answer 3

Identify antigens by interacting with APCs (macrophages and dendritic cells)

Question 4

What is electrophoresis?

Answer 4

Electrophoresis of serum identifies different globulins
Serum proteins are called globulins and are named by their mobility in the assay

Question 5

What are gamma globulins?

Answer 5

Immunoglobulins
Increase after infection
On the far right in electrophoresis

Question 6

Which parts of the antibody bind to what?

Answer 6

Variable region binds to antigens
Constant region bind to receptors within immune system - called Fc receptors

Question 7

Describe the structure and function of IgG

Answer 7

Secreted into blood supply
Removes pathogens from blood and tissues
Major antibody

Question 8

What is the action of IgG?

Answer 8

1. Variable region binds to antigen and leaves Fc domain exposed
2. A cluster of Fc domins generates a signal to the immune system
3. Recruits a complement cascade to the surface of the pathogen
4. Generates a membrane attack complex that kills the pathogen
5. Second signal recruits phagocytosis cells e.g. macrophages
6. Opsonisation and phagocytosis
7. Phagocytes Aldo generate ROS to help kill pathogens

Question 9

What is the structure of IgA?

Answer 9

Made of 2 immunoglobulin A molecules joined at their tails by joining (J) protein

Question 10

What is the function of IgA?

Answer 10

Important for defence against infection at mucosal surfaces
Made in large quantities, 5g secreted unto gut daily

Question 11

What is the action of IgA?

Answer 11

1. IgA binds to IgA receptor and secreted across epithelial cells to protect mucosal surfaces
2. Secretion occurs as tail of IgA binds to IgA receptor which carries IgA across the epithelial cells
3. Secreted IgA able to bind to pathogens that have not yet entered the body

Question 12

What is the structure of IgE?

Answer 12

Look like IgG but different Fc domain

Question 13

What is the function of IgE?

Answer 13

Secreted into blood supply and bind to IgE receptors on mast cells and eosinophils
For defence against parasite infections of tissues

Question 14

What is the response to parasites by IgE?

Answer 14

1. Defines antigen specificity of eosinophils and mast cells
2. Binding to IgE receptors causes release of inflammation mediators like histamines
3. Mast cells release histamine allowing IgE to defend against parasites
4. Eosinophils damage parasites via release of: peroxidase, ribonuclease, deoxyribonuclease, lipase, plasminogen, major basic protein

Question 15

Describe the role of IgE in allergies

Answer 15

1. If the body asks an IgE that recognises an allergen it will bind to allergen
2. Triggered histamine release from mast cells
3. Can also contribute to asthma

Question 16

How the instant region of an antibody determine the function of the antibody?

Answer 16

By finding the right effector cell
This allows vaccination to protect all sites of infection

Question 17

What is the function of cytotoxic T-cells?

Answer 17

Recognises infected cells and kill them
Kills tumour cells
Contains granules filled with enzymes e.g. perforin, release these enzymes into space between T-cell and infected cell - kills infected cell

Question 18

What is the function of helper T cells?

Answer 18

Help B-cells to make antibodies