Lecture 18: Tumor Immunology

Question 1

Diverse collection of diseases that result from abnormal and invasive cell proliferation

Answer 1

cancer

Question 2

Why does the immune system fail to see cancer cells as “foreign”?

Answer 2

very similar to normal cells

Question 3

“Swelling”

Answer 3

tumor

Question 4

Tissue containing abnormally multiplying cells

Answer 4

tumor

Question 5

Metastasis

Answer 5

spreading of tumor cells through lymph or blood

Question 6

Carcinomas involve

Answer 6

epithelial cells

Question 7

Sarcomas involve

Answer 7

non-epithelial cells

Question 8

Leukemias involve

Answer 8

circulating cells

Question 9

Lymphomas involve

Answer 9

solid lymphoid tumors

Question 10

Myelomas involve

Answer 10

bone marrow

Question 11

Where do melanomas occur?

Answer 11

Skin

Question 12

Where do lymphomas occur?

Answer 12

lymph nodes

Question 13

Where does leukemia occur?

Answer 13

Bone marrow

Question 14

What mutagens are especially associated with cancer?

Answer 14

chemicals, radiation, viruses

Question 15

A mutagenic agent causes:

Answer 15

increased mutation rate

Question 16

How do tumor specific antigens play a role in tumor cell elimination?

Answer 16

CTLs can recognize these and kill the tumor cell

Question 17

What happens when a mutated protein is presented on an MHC I?

Answer 17

Since it is no longer a “self” determinant, it can be recognized by a CD8

Question 18

What are 3 types of tumor associated antigens?

Answer 18

1) Proteins resulting from reactivated embryonic genes
2) Proteins resulting from mutations
3) Overexpressed self proteins (whose density results in naive T cell recognition)

Question 19

How are tumors able to evade immune responses?

Answer 19

Mutations, which are selected for when they are no longer recognized pre-formed immune responses

Question 20

What cells are involved in tumor immunity?

Answer 20

CTLs and NK

Question 21

Why is it significant that up to half of human tumors have defects in expression in 1 or more HLA class I allotypes?

Answer 21

CTLs will be unable to recognize the cells

Question 22

How can a tumor suppress its environment?

Answer 22

Produce cytokines (such as TGF-beta)

Question 23

How is an antibody humanized, why?

Answer 23

Add human heavy chains so the antibody can be recognized by human Fc receptors

Question 24

What are 2 function of humanized monoclonal antibodies?

Answer 24

diagnostics or treatment

Question 25

How do humanized monoclonal antibodies carry out target killing of tumor cells?

Answer 25

hmAbs are conjugated to toxins or radionuclides

Question 26

In order to use hmAbs as treatment, what is necessary?

Answer 26

Tumor specific antigens must be present (so Ab can be made against them)

Question 27

How does a conjugated toxin kill a tumor cell?

Answer 27

The antibody binds to a surface receptor (example: CD33) on a target cell
Once internalized, the toxin is cleaved and activated
The toxin can pass into the nucleus, where it creates double stranded breaks in the DNA (and apoptosis)

Question 28

How does a radionuclide kill a tumor cell?

Answer 28

Radioactive nuclide Ab binds to malignant B cell and irradiates it
Radiation damages the cells DNA and kills the cell

Question 29

QUESTIONS NEEDED ABOUT THE MOUSE IMAGE

Answer 29

WTF