Final Content - week 8 Flashcards

(70 cards)

1
Q

What’s B7?
Where is it located?

A

A ligand
On APC

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

What’s CD28?
Where is it located?

A

A receptor protein
On CD8+

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

Whats MHC-1?
Where is it located?

A

A precenter molecule
On APC

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

What’s TCR?
Where is it located?

A

T-cell receptor
On CD8+

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

What’s CTLA-4?
Where is it located?

A

A receptor protein
On CD8+

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

CD8+ activation pathway: mechanism 1

A

B7 - CD28 binding

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

CD8+ activation pathway: mechanism 2

A

MHC1 - Antigen - TCR binding

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

What happens upon CD8+ activation?

A

CD8+ T cells become cytotoxic T lymphocytes (CTLs), killing antigen of interest via cellular attack

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

CD8+ inhibition pathway: mechanism 1

A

MHC1 - Antigen - TCR and B7 - CTLA4 binding

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

CD8+ inhibition pathway: mechanism 2

in which cell is the receptor present? the ligand?

A

PD-1R / PD-Ligand binding

PD1R located on the T-cell
PDL located on APCs or target cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens upon CD8+ inactivation?

A

There will be no cellular attack

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Is CD8+ inhibition a good thing?

A

Generally, yes. Inhibition pathways, also known as immune checkpoints, are there to inhibit autoimmunity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What’s autoimmunity?

A

immune system attacking healthy tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Are CD8+ activation and inactivation both immune checkpoints?

A

No, only CD8+ inactivation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are TATA/TSTA?

A

Tumor antigens w/ immune response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is immunogenic?
what are some examples?

A

capable of triggering immune response
e.g. TATA/TSTA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are immunogenic tumor antigens?

A

molecules found on cancer cells that immune system recognizes to target cells for its death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Explain the hallmark - avoidance of immune destruction

A

cancer avoiding immune system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Hallmark - Avoidance of immune destruction: down regulation of tumor antigens.

Explain:
(a) what this means
(b) how is this accomplished

A

(a) cancer can hide its identity such that CD8+ T-cells cannot detect it

(b) Cancer undergoes immuno editing to remove non-critical functional antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Hallmark - Avoidance of immune destruction: Avoids by down regulating MHC-1 expression

Explain:
(a) what this means
(b) how is this accomplished

A

(a) MHC-1 is not properly displayed on cell membrane

(b) cancer cells lose proteins that usually drive MHC1 onto the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Hallmark - Avoidance of immune destruction: decrease stress signals

Explain:
(a) what this means
(b) how is this accomplished

A

(a) there is a decrease in MHC1 cells so that neither T or NK cells kill cancer

(b) decoy MICB/MICA bind to NKG2D receptor on NK cells
–> healthy MICB/MICA remain in cancer cells but do NOT interact w/ NK cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

If cancer cells aren’t killed by CD8+ T cells, what else has the ability to kill cancer cells?

A

NK cells (Natural Killer cell)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the difference between healthy MICB/A cells and decoy MICB/A?

A

healthy = located on cell surface and signal NK cell activation

decoy = secreted from cancer cells and act as deceptive molecules, preventing NK cell activation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Hallmark - Avoidance of immune destruction: decrease apoptosis

“don’t kill me”

Explain:
(a) what this means
(b) how is this accomplished

A

(a) apoptosis - programed cell death - is decreased

(b) there is a decrease in the FASR - FASL binding in FAS mediated apoptosis. IAPS will increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what does IAPs stand for?
Inhibitors of Apoptosis Proteins
26
Hallmark - Avoidance of immune destruction: cancer counteracts "I'll kill you instead" Explain: (a) what this means (b) how is this accomplished
(a) cancer kills healthy cells instead (b) 1. tumor cells release soluble FASL that bind T-cell FASR (t-cell receptor), inducing FAS mediated apoptosis in T-cells 2. increase in PD1R on tumor cell - decreases effectiveness of cancer cell apoptosis 3. release cytotoxins to inhibit + kill T-cells via attraction and activation of TREGs
27
What's TREGs?
* TREGs stand for Regulatory T cells * They are a type of immune cell * suppress the immune response -->global inhibitor of the immune response
28
Is TREGs good or bad in terms of cancer?
Bad: tumors can exploit TREGs to evade immune attack.
29
PAP is common in what type of cancer?
Prostate cancer
30
Therapeutics - passive immunity. Explain what it means
introducing antibodies or immune cells from another source
31
what is ADCC - Antibody-Dependent Cellular Cytotoxicity?
attack innate immune cells such that they do NOT need a specific antigen for immune response --> process where cells destroy target cells that are coated w/ antibodies
32
Immunology therapeutics: Vectibix
EGFR antibody against colorectal cancer --> monoclonal antibody --> induce ADCC against CC
33
Immunology therapeutics: Herceptin
HER2-R antibody against breast cancer --> monoclonal antibody --> induce ADCC against CC
34
Immunology therapeutics: Avastin
Anti-VEGF (decreases angiogenesis) --> monoclonal antibody --> induce ADCC against CC
35
Immunology therapeutics: Rituxan
D20 antigen antibody (B-cell cancers, non-hodgkins lymphoma) --> monoclonal antibody --> induce ADCC against CC
36
Immune checkpoint therapeutics: Yervoy
(a) antibody blocking CTLA-4 checkpoint (b) increases cytotoxic T cell activation
37
Immune checkpoint therapeutics: Keytruda
(a) antibody blocking PD-1 checkpoint (b) increases cytotoxic T cell killing
38
what are immune checkpoint co-stimulatory/inhibitory molecules involved in?
in regulating T cell activation
39
Oncolytic virus therapeutics: T-vec
(a) oncolytic virus - modified herpes simplex virus that selectively infects and kills cancer cells (b) only replicates in cancer cells
40
Direct Killing - explain the prupose/mechanism.
an immune system's way of eliminating abnormal cells via cell-to-cell contact
41
what are some examples of cells that kill via direct mechanism?
Cytotoxic T lymphocytes (CTLs) Natural Killer (NK) cells:
42
Systematic Killing - an immune system's way of eliminating abnormal cells. explain the mechanism
immune system launches a larger, coordinated attack against abnormal cells -->It doesn't rely on direct cell-to-cell contact.
43
what are some examples of cells that kill via systematic mechanism?
Antibody-dependent cellular cytotoxicity (ADCC) Cytokines
44
Therapeutic vaccines: provenge
(a) Adoptive cell therapy (b) FDA approved therapeutic vaccine for metastatic prostate cancer
45
how does provenge work?
(a) uses body's immune cells to fight cancer (b) results in stronger immune cells that are able to fight cancer --> essentially boosts and amplifies immune cells via provenge
46
Therapeutic vaccines: CAR-T cells
Patiens own t-cells removed via blood and undergo genetic modifications which results in better t-cells --> injected back into patient and won't be rejected bc its their own cells
47
CAR-T cell adjustment 1 problem and solution
problem: tumors down regulate MHC-1 solution: Cells are modified to gain the ability of recognizing an antibody located on the tumor surface w/o the need of MHC-1
48
CAR-T cell adjustment 2 problem and solution
problem: CAR-T cells can cause autoimmunity solution: adding self activating domains to CAR-T cells such that they can self activate
49
CAR-T cell adjustment 3 problem and solution
problem: CAR-T cells might not be as effective solution: increase co-stimulatory molecules (CD28) expressed on cell surface
50
What is a way in which cancer cells are able to evade CAR-T cells even after modifications?
the tumor cell removes antigens given that antigens can be recognized even without MHC1
51
What is another way in which cancer cells are able to evade CAR-T cells even after modifications?
T-cell exhaustion via cancer cells releasing PDL into extracellular fluid. CAR-T cells will bind PDL @ a higher frequency which deactivates T-cells
52
Can CAR-T cells fight cancer adjustments? how?
yes, by further modification
53
Whats a further modification used to fight cancer adjustments?
CAR-T cell's native receptor, PD1, is removed
54
4th gen CAR-T cells - TRUCKS (a) modification? (b) why?
(a) modification: added production of immuno-stimulating molecules (b) to increase T cell activity and decrease TREG activity
55
5th gen CAR-T cells (a) modification? (b) why?
(a) removed self activating domain and instead, activation is tied to antigen binding (b) to minimize off-target effects of car-t cells as too much co-stimulatory domains can potentially attack cells outside of cancer
56
what are the current problems with ex-vivo production of car-t cells?
(a) excessive immune response - cytokine release syndrome (CRS) - overactive immune system can hurt us (b) Parkinsons-like symptoms in CAR-T cell patients - Immune Effector Cell-Associated Neurotoxicity - in repose to overactive CAR-T cells
57
what are some future CAR-T cell therapies?
Addition of NK signals Combinatorial therapies using -->Immune checkpoint blockers -->VEGF antibodies -->Different antigens
58
Hallmark of cancer: angiogenesis explain
Formation of new capillaries - the smallest blood vessels in your body - from current vessels; tightly regulated
59
explain the early process of angiogenesis. a - d
(a) cell proliferation - rapid and uncontrolled division - releases growth factors such as VEGF/EGF via RAS/PI3K pathway (b) matrix degradation occurs - degradation relies on proteases (c) cancer cells begin migration away from main tumor - relies on EMT (epithelial-mesenchymal transition) to increase motility (d) re-establishment - restoring blood flow and nutrient supply to the growing tumor.
60
Normal angiogenesis process - 4 total
1. embryonic development 2. wound healing 3. menstruation 4. growth
61
Pathological angiogenesis - 3 total
1. psoriasis 2. diabetic retinopathy 3. cancer
62
angiogenic therapeutics - 4 total
1. heart attacks 2. natural damage 3. bone healing 4. blood flow
63
tumor angiogenesis: What is the rate limiting step in tumor growth?
Nutrients & oxygen
64
tumor angiogenesis: How large can a tumor grow with limited blood supply?
1-2mm
65
tumor angiogenesis: What process do tumors go through to solve this problem?
angiogenesis
66
ANGIOGENIC SWITCH: What characterizes angiogenic vasculature in tumors? 4 total
1. Disorganization, leaks, improper cell junctions - Caused by an excess of positive factors 2. Poorly associated pericytes --> Pericytes: support cells for vasculature, tightly associated with basement layer 3. Lack of vessel-type distinctions --> Capillaries vs. venules vs. arterioles 4. Holes to the basement layer - Lack of endothelial cells; not forming a distinct layer
67
ANGIOGENIC SWITCH: What triggers an angiogenic switch? 3 total
1. Activation of oncogenes ex. RAS/MAPK pathway 2. Down-regulation of tumor suppressors ex. p53 3. Environmental cues ex. hypoxia
68
whats HIF-Alpha?
Hypoxia-Inducible Factor-alpha - a protein that plays a critical role in the body's response to low oxygen levels (hypoxia
69
explain HIF-Alpha w/ oxygen
Hif-a will associate w/ VHL protein to target it for degradation which results in no VEGF production
70
explain HIF-Alpha w/o oxygen - hypoxic state
hif-a translocates into nucleus and beings VEGF transcription