B2 - Monoclonal Antibodies

Question 1

What are antibodies produced by?

Answer 1

White blood cells.

Question 2

Monoclonal antibodies are made from lots of clones of a single white blood cell. What does this mean?

Answer 2

All the antibodies are identical and will only target one protein antigen.

Question 3

How do you make monoclonal antibodies? (5 marks)

Answer 3

Animal (usually a mouse) injected with chosen antigen
The white blood cells in the mouse which recognise the antigen will start to divide and produce antibodies.
Blood taken from the mouse and cell produced from the right antibody are extracted
The cell are fused with tumour cells (because they divide many times).
The resulting cells are placed in a culture medium. This produces many cell that can produce lots of the antibody.

Question 4

Monoclonal antibodies can be made to bind to anything. Why is this useful?

Answer 4

They will only bind to a specific molecule. So it can be used to target a specific cell in the body

Question 5

How can monoclonal antibodies help in diagnosing a disease?

Answer 5

Monoclonal antibodies can be made to detect a particular pathogen

Question 6

What pathogen causes malaria?

Answer 6

Plasmodium falciparum

Question 7

What is used Plasmodium falciparum pathogen detected in a sample of blood?

Answer 7

A diagnostic stick

Question 8

What is on a diagnostic stick for malaria?

Answer 8

Monoclonal antibodies specific to the antigens on the surface of plasmodium.

Question 9

How are the monoclonal antibodies on a malaria diagnostic stick labelled?

Answer 9

With dye.

Question 10

What happens to the blood sample on a malaria diagnostic stick if the disease is detected?

Answer 10

The blood sample and the antibodies move along the length of the stick towards a test strip.
Monoclonal antibodies which also recognise the plasmodium antigens are stuck to the test strip.
If the pathogen is present then the antibodies on the test strip and the antibodies which are stuck to the dye will bind to the pathogens antigens and the test strip will change colour.

Question 11

What happens to the blood sample on a malaria diagnostic stick if the pathogen is not present?

Answer 11

The blood sample and the antibodies move along the length of the stick towards a test strip.
Monoclonal antibodies which also recognise the plasmodium antigens are stuck to the test strip.
If the pathogen is not present then the labelled monoclonal antibodies will not become stuck to the test strip and it won’t change colour.

Question 12

Why does using a diagnostic stick to detect malaria result in the patient receiving the correct treatment sooner?

Answer 12

Because the test is very sensitive and specific to only one pathogen this means that diagnosis is quicker and more accurate than was previously possible

Question 13

What can monoclonal antibodies be used for?

Answer 13

To diagnose and treat a disease.

Question 14

Why are monoclonal antibodies good at killing cancer cells? (3 marks)

Answer 14

Because they can be programmed to target a specific cells
As well as tagging specific for the immune system to destroy
And to deliver drugs to specific locations

Question 15

What are tumour markers?

Answer 15

Antigens found on cancer cells membranes that aren’t found on normal body cells.

Question 16

Why aren’t cancer cell attacked by the white blood cells in the immune response?

Answer 16

As cancer are produced by the body’s he tumour markers aren’t recognised by the body as foreign.

Question 17

How are monoclonal antibodies made in the lab to treat cancer?

Answer 17

Monoclonal antibodies will bind to the tumour markers and be used to treat the cancer.

Question 18

Monoclonal antibodies trigger a normal immune response to cancer cells. How does this happen? (3)

Answer 18

(1) monoclonal antibodies are injected into the patient’s blood stream.
(2) The antibodies bind to the tumour marker on the cancer cells.
(3) for some types of monoclonal antibodies the cell is labelled and there is a normal immune response e.g. the patient’s body recognise the cells as foreign and attack them

Question 19

Monoclonal antibodies can target drugs to cancer cells. How do they do this?

Answer 19

(1) Anti-cancer drug is attached to the monoclonal antibodies.
(2) Antibodies injected into the patients blood stream and they bind to the cancer cells
(3) the drug kills the cancer cells but doesn’t kill any normal cell near the tumour

Question 20

Describe an anti-cancer drug that is attached to monoclonal antibodies.

Answer 20

It might be a radioactive or toxic substance that stops cancer cell growing and dividing.

Question 21

What are other cancer treatments and what are their side effects?

Answer 21

Radiotherapy and chemotherapy.

Side effects: hair loss and vomiting.

Question 22

Why do antibody based drugs have less severe side effect than radiotherapy and chemotherapy treatments.

Answer 22

Antibody based drugs are targeted directly to the cancer cells.
Radiotherapy and chemotherapy effect healthy cells as well as the cancer cells.

Question 23

Explain how monoclonal antibodies can be used to deliver drugs to cancer cells. (3 marks)

Answer 23

anti cancer drugs can be attached to monoclonal antibodies(1 mark)
They are injected into the patient’s blood stream (1 mark)
The monoclonal antibodies bind to specific tumour markers on a cancer cell and so deliver the drug to these cells