FINAL EXAM: Immunity to Tumors

Question 1

Altered self-cells that fail to grow normally are called…?

Answer 1

Tumor or neoplastic cells

Question 2

Benign tumor

Answer 2

Not capable of indefinite growth

Question 3

Malignant tumor

Answer 3

CANCER- continues to grow and is progressively invasive

Question 4

How does a metastastic tumor spread?

Answer 4

Via lymph or blood

Question 5

Carcinoma

Answer 5

Malignant tumor of epithelial cells

Question 6

Sarcoma

Answer 6

Solid tumor of connective tissue

Question 7

Leukemia

Answer 7

Malignant tumor of of bone marrow cells that proliferate as single cells

Question 8

Lymphoma

Answer 8

Malignant tumor of bone marrow cells that grow as tumor masses

Question 9

How are tumor antigens classified?

Answer 9

Based on their pattern of expression

Question 10

TSA

Answer 10

Tumor specific antigen

Question 11

How are TSAs induced?

Answer 11

By viruses or carcinogens

Question 12

FOCMA antigen

Answer 12

Virus-induced TSA found on neoplastic lymphoid cells of cats with Feline Leukemia Virus

Question 13

Carcinogens induce ________ mutations

Answer 13

random

Question 14

TAA

Answer 14

Tumor Associated Antigens

Question 15

Where and when are TAA’s expressed?

Answer 15

Expressed on normal cells, but higher in concentration in cancer patients

Question 16

How are tumor antigens (TAAs) processed, presented and recognized?

Answer 16

Processed as cytosolic proteins.
Presented as peptides together with class I MHC molecules on the surface of tumor cells
Recognized by CTLs as altered self-cells

Question 17

What are reactivated gene products?

Answer 17

Products of developmental genes only expressed during embryonic development

Question 18

Oncofetal genes

Answer 18

Cancer cells only in embryonic or fetal life that do NOT provoke protective immunity

Question 19

Why are oncofetal genes clinically relevant?

Answer 19

Important for tumor diagnosis

Question 20

AFP

Answer 20

Alpha-fetoprotein

Question 21

What does AFP do?

Answer 21

It is an immunoregulatory protein found majorly in fetal serum

Question 22

Where is AFP synthesized?

Answer 22

Yolk sac and fetal liver

Question 23

When would you see elevated AFP levels?

Answer 23

In patients with hepatocellular carcinoma

Question 24

CEA

Answer 24

Carcinoembryonic antigen

Question 25

Where is CEA found?

Answer 25

Integral membrane protein found on: gastrointestinal cells pancreatic cells liver cells

Question 26

When is CEA found?

Answer 26

During the first 2 trimesters of gestation

Question 27

When would you see increased levels of CEA?

Answer 27

In patients with carcinomas of the colon, pancreas, stomach, and breast.

Question 28

What does CEA do?

Answer 28

It is an intercellular adhesion molecule that promotes the binding of tumor cells to one another

Question 29

CEA and AFP are both what?

Answer 29

Oncofetal antigens

Question 30

Tumor antigens induce both ______ and _____ responses that results in the killing of tumor cells.

Answer 30

Humoral and CMI responses

Question 31

CTLs

Answer 31

CD8+ Cytolytic T Lymphocytes

Question 32

What do CTLs do?

Answer 32

Kill malignant cells expressing mutant cellular proteins or oncogenic viral proteins

Question 33

What is cross-priming in relation to CTLs?

Answer 33

The process of expressing co-stimulators that provide the 2nd signals needed for differentiation of CD8+ T cells into antitumor CTLs

Question 34

Do effector CTLs need co-stimulation in order to recognize and kill tumor cells?

Answer 34

NO

Question 35

What do NK (natural killer) cells do?

Answer 35

Kill tumor cells that have reduced class 1 MHC expression

Question 36

What receptor is commonly found on NK cells?

Answer 36

FcyRIII [CD16]

Question 37

What does the FcyRIII [CD16] receptor on NK cells do?

Answer 37

Binds to IgG coated tumor cells leading to ADCC

Question 38

What receptors are found on macrophages that allow them to bind to IgG coated tumor cells and mediate ADCC?

Answer 38

Fcy receptors

Question 39

When macrophages kill tumor cells, what is released?

Answer 39

Nitric Oxide and cytokine TNF-a.

Question 40

What does TNF-a do to tumors when secreted by activated macrophages?

Answer 40

Causes hemorrhage and necrosis of the tumor

Question 41

How do antibodies kill tumor cells?

Answer 41

By activating complement or by ADCC with NK cells and macrophages

Question 42

How do tumors evade immune responses?

Answer 42

By failing to produce tumor antigen, not expressing Class 1 MHC molecules, lack of co-stimulation, immunosuppresion or antigen masking. This causes T- cells to not be able to recognize the tumor cell.

Question 43

How do tumors achieve antigen-masking?

Answer 43

By increasing their expression of of cell surface glycocalyx molecules

Question 44

What are some methods of tumor immunotherapy?

Answer 44

``` Cytokine therapy Tumor Necrosis Factor Interferons Adoptive Cellular Therapy Monoclonal antibodies Tumor Vaccines ```