Tumour immunity

Question 1

What happens to cells when they are referred to as cancer?

Answer 1

• Damaged cells do not undergo programmed cell death
• Growth/replication is no longer controlled
• Cellular metabolism is altered

Question 2

What is a tumour?

Answer 2

A swelling or lesion caused by an abnormal growth of cells

Question 3

What is the difference when a tumour is cancerous?

Answer 3

Arises from a single cells that uncontrollably proliferates

Question 4

What are the different possible causes of tumours?

Answer 4

• Oncogenes
• Carcinogens
• Age
• Gender susceptibility
• Immune deficiency
• Infection

Question 5

What is an oncogene?

Answer 5

Protein encoding genes which if deregulated trigger the onset and development of cancer

Question 6

Define a benign and malignant tumour

Answer 6

Benign - at a single site, local, cannot spread by invasion or metastasis
Malignant - forms a secondary tumour, causes tissue damage which leads to inflammation, cells invade neighbouring tissues and enter blood stream

Question 7

Which types of tumours can be treated surgically?

Answer 7

Benign and pre-malignant

Question 8

What happens when a malignant tumour is first recognised by the host?

Answer 8

It is seen as a wound and triggers a normal innate immune response - sends a wave of macrophages to the site

Question 9

What is a neoantigen?

Answer 9

These can be detected in tumours by immunosurveillance, most are abnormal self-proteins, which when recognised, trigger an immune response

Question 10

What are the different tumour antigens?

Answer 10

• Can be excessive amounts of normal proteins or tumour specific antigens
• Tumours rarely express new antigens, they are often normal proteins that are abnormal in some fashion

Question 11

What response can promote tumour formation?

Answer 11

Inflammation

Question 12

What is tumour surveillance?

Answer 12

A system of immunosurveillance which eradicates tumours before they can grow

Question 13

Which cells are involved in targeting tumour cells found during tumour surveillance?

Answer 13

• Macrophage
• Dendritic cell
• CD8 cell mediated cytotoxicity
• NK cell
• Antibody dependent cell cytotoxicity

Question 14

Which 3 cells are involved in tumour immunity?

Answer 14

Cytotoxic CD8 T-cell
Macrophages
NK cells

Question 15

Which cells are relied on to recognise the tumour antigen within an MHC complex?

Answer 15

CD8 killer cells

Question 16

Why can CD8 t-cells not cause cell death?

Answer 16

Tumour cells are immune

Question 17

What is the role of the B-cell compartment in the adaptive immune response to tumour immunity?

Answer 17

B-cells are converted into plasma cells which produce antibodies specific to the neoantigen - they coat the tumour which triggers antibody dependant cell cytotoxicity (ADCC) from an NK cell

Question 18

Describe ADCC activity against tumours

Answer 18

• Tumour antigen mediated attack by NK cells

- Innate and lack memory

Question 19

What are tumour associated macrophages?

Answer 19

Under the control of the tumour and allow tumour maintenance

• Angiogenesis = new blood vessel development
• Tumour invasion of tissues
• Inflammation

Question 20

What is immunotherapy?

Answer 20

Stimulating them immune system to attack tumours

Question 21

Which cells/molecules are involved in non-specific immune stimulation during immunotherapy?

Answer 21

• Microbial products
• Cytokines = Interferons, Tumour necrosis factor, IL-2, IL-4
• Cytokine activated cells = T-cells, NK cells

Question 22

What are active and passive immunisation (immunotherapy)?

Answer 22

Active = Inject with modified tumour cells
Passive = Inject anti-tumour antibodies