Tumor Immunology

Question 1

What cells are most important in the immunologic response to cancer?

Answer 1

CD 8+ T Cells

Question 2

What is the difference between tumor-specific antigens and tumor-associated antigens?

Answer 2

Tumor-specific antigens are expressed only on tumor cells and not on normal cells.

Tumor-associated antigens are expressed on tumor cells, but may also be expressed at low levels on normal cells.

Question 3

What tumor-associated antigen is overexpressed in many breast cancers?

Answer 3

HER2

Question 4

How are tumor antigens presented to T cells?

Answer 4

They are presented on MHC I to CD 8+ T cells

Question 5

By what process are CD 8+ T cells activated?

Answer 5

Cross presentation - APCs ingest cancer antigens and present on MHC I to CD 8+ T cells

Question 6

What type of immune response (Th1, Th2, Th17) is associated with cancer immunity?

Answer 6

Th1 response promoted by CD 4+ T cells

Question 7

What is the function of IFN-y?

Answer 7

Pro-inflammatory cytokine

Question 8

Through what two methods can CD8+ T cells kill tumor cells?

Answer 8

Perforins & Granzymes to induce apoptosis

Question 9

What cells are responsible for kill tumor cells that do not express MHC I?

Answer 9

NK cells

Question 10

There are two pathways for macrophage activation. Which pathway is responsible for promoting tumor suppression?

Answer 10

M1 - Classical Pathway

Question 11

There are two pathways for macrophage activation. Which pathway is associated with promotion of tumor growth?

Answer 11

M2 - Alternative Pathway

Question 12

Tumors prefer an environment with (low/high) inflammation?

Answer 12

Low inflammation - creating an anti-inflammatory environment is one way tumors evade the immune response

Question 13

Some tumors promote the induction of regulatory T cells and peripheral tolerance when tumor antigen is presented. How is this possible?

Answer 13

Tumor cells present PD-1 on their surface that binds to B7 on CD4+ T cells and inhibits an immune response

Question 14

True/False. Any immune response generated by T cells will attack the tumor.

Answer 14

False. The immune system may generate a response based on tumor antigen presentation, but tumors mutate and change so rapidly that the antigen may no longer be expressed or the tumor developed a way to evade the response

Question 15

What are the four general methods by which tumors evade an immune response?

Answer 15

1. Fail to produce tumor antigens
2. Reduced activation of APCs
3. Inhibition of T cell activation
4. Inhibition of T cell response

Question 16

What is a major shortcoming of tumor vaccines?

Answer 16

You must already have a tumor before for the vaccine to be effective

Question 17

What is the MOA of Bispecific T Cell Engager monoclonal antibodies?

Answer 17

Facilitate T cell destruction of tumor cells by binding both a tumor antigen and a T cell

Question 18

What is the use of the BCG vaccine in cancer therapy?

Answer 18

Used in the treatment of bladder cancer - Bacteria bind tumor cells and facilitate an immune response

Question 19

What is the MOA of immune checkpoint blockade antibodies for cancer therapy?

Answer 19

Antibodies block PD-1 & CD28 to prevent inhibitory signaling by tumor cells and promote T cell activation

Question 20

Why are CAR T cells effective in treating tumors?

Answer 20

The T cells bypass the normal activation mechanism and cannot be inhibited by PD-1 or CTLA-4 binding

Question 21

CAR T therapy is indicated for use in what type of cancer?

Answer 21

Lymphoblastic leukemia

Question 22

What are the possible ADRs associated with immunological tumor treatments?

Answer 22

Cytokine syndrome, destruction of normal B & T cells, tumor is not completely eradicated

Question 23

What are the primary anti-inflammatory cytokines that are stimulated by some tumors?

Answer 23

IL-10 & TGF-B