281 - Tumor Immunology Flashcards

1
Q

What is pseudoprogression after immunotherapy?

A

Tumor appears to grow at first

(probably due to lots of immune cells going there)

Be patient! Likely to regress later

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Briefly describe the oncolytic virus approach to treating melanoma

A

HSV-1 is re-engineered to fight melanoma -> TVEC

  • TVEC is injected into tumor
  • Causes tumor lysis, expression of GM-CSF in the microenvironment
  • Attracts lots of immune cells
  • -> anti-tumor response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the difference between type 1 and type 2 macrophages?

A

Type 1 (M1) = turn on adaptive immunity

Type 2 (M2) = limits adaptive immunity

  • M1’s are eager and excitable*
  • M2’s are burnt out ard ready to limit activities*
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the most significant side effect of immune therapies?

A

Autoimmunity

  • Goal is to maximize immune response to tumor, but also need to prevent autoimmunity*
  • Rash/desquamation, colitis, hypophysitis, encephalitis*
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

List 2 things that can prevent T-cell activation

1 during the priming phase, 1 in the tumor microenvironment

A
  • Priming: T-cell can express CTLA-4
    • Binds APC’s B7 with higher affinity than T cell’s CD28
    • CD28 needed for secondary activation; if CTLA-4 binds B7, B7-CD28 interaction cannot occur and T-cell does not activate
  • Tumor environment: Tumor cell can expres PD-L1
    • Binds to T-cell PD-1 receptor
    • Prevents T-cell activation
    • Anti-PDL1 or Anti-PD1 therapies prevent this interaction, allow the T-cell to become active

Using a combo of Anti-PDL1 and anti-CTLA4 = helpful!!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which cells activate T cells via the T cell recpetor?

A

Dendritic cells

Causes T cells to differentiatie into CD4+ helper or CD8+ cytotoxic

Dendritic cells = key link between innate and adaptive immunity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the primary and secondary signals that work together to activate T-cells?

A
  • Primary
    • APC presents antigen on MHC to T-cell receptor
  • Secondary
    • APC expresses B7, which binds to CD28 on the T-cell

If T-cell expresses CTLA-4, it has a higher affinity for B7 than CD28; will prevent activation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does the immune system normally work to fight cancer?

A
  • Innate immune cells cause cancer lysis
    • Antigen-indeepndent process
    • Creates tumor neoantigens
  • Dendritic cells uptake neoantigens
    • Express to T-cells; antigen dependent
    • Activates the adaptive immune system
  • T-cells become activated
  • ​CD8+ cytotoxic T cells go to the tumor
    • Antigen-dependent cell death
    • Goal is to shrink tumor

Things in blue = drugs that can augment this system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do tumors evade the immune system?

A
  • Equilibirium
    • Tumor cells are there, but they are dormant - hiding from the immune system
  • Escape
    • Tumor figures out how to take over without being caught by the immune system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which cells are involved in the innate and adaptive immune systems?

A
  • Innate
    • Macrophages
    • Dendritic cells
    • NK cells
    • Neutrophils
  • Adaptive
    • T cells
    • B cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly