Quiz 7 - German - NK And Gamma Delta Cells Flashcards
What are NK cells?
Lymphocytes
What do NK cells do?
Destroy diseased and dysfx self cells
Diverse receptor expression and interaction
May form memory cells
Balance of activating and inhibitory signals
NK cells interact with which MHC?
- MHC Class I*
- Same with CD8 cells
How do NK cells recognize targets?
By lack of MHC I
So, not a self cell, or cell may not be the correct self cell (Transplant issues)
What 3 things do NK cells do when activated?
Cytokine release
Divide and proliferate
Kill directly
What does MHC typically present when the cell is infected?
Usually viruses
*Peptides are expressed, but this class expresses viral infections
Where are NK cells found?
All over body, especially the periphery
T/F - NK cells will kill unless inhibited via an inhibitory receptor.
TRUE
Occurs when a normal, healthy cell expresses MHC I and inhibits activation from occurring
If a cell is lacking MHC I, what happens?
NK cell is activated and kills the cell
Cancer cells and cells affected by a pathogen that has caused the MHC to be not expressed
T/F - NK cells have an inhibitory receptor and a stimulatory receptor. If the stimulatory receptor is not overcome via the inhibitory receptor, the NK cell is activated.
TRUE
What happens when a cell is stressed?
NK cell receives more stimulating signals than inhibitory signals
*Virus infected cells
What 3 cell states regulate NK cell targeting?
Protection
-Healthy cells express both stimulating and inhibitory signals
Missing-self
-Unhealthy cells reduce MHC I expression
Induced-self
-Unhealthy cells increase stress ligand expression
T/F - To be inhibited, the stimulating signals must be overcome by inhibitory signals.
TRUE
What do cytokines do in NK cell killing?
Stimulating signals
Receptor expressing
Release IFNs, IL-12
Which receptors are activating?
Which receptors are inhibitory?
Activating
- NKG2D
- CD16 (Fc receptor)
Inhibitory
- NKG2A
- KIR Family
The activating receptors are structured how and what is their ligand structure?
- NKG2D
- CD16 (Fc receptor)
NKG2D -Receptor structure —Lectin-like -Ligand structure —MHC Class I (Similar to that)
CD16 -Receptor structure —Ig-like (2) -Ligand structure —Immunoglobulin
The inhibitory receptors have what structure and their ligands have what structure?
- NKG2A
- KIR Family
NKG2A -Receptor structure —Lectin-like -Ligand structure —MHC Class I
KIR Family -Receptor structure —Ig-like (2 or 3) -Ligand structure —MHC Class I
What are the 3 major NK cell receptor families?
CD16 (This is an override, the NK cell will be activated if this is bound)
-IgG Fc receptor
—Activating receptor
NKG Family
- NKG2A - INHIBITORY - Binds MHC I
- NKG2B - ACTIVATING - Binds MIC proteins
KIR (Killer-cell Ig-like Receptor) Family
- INHIBITORY - Binds MHC I
- Detects healthy self tissue*
Inhibitory receptors recognize conventional _____ ___.
Activating receptors recognize ________ ________.
MHC I
Stress ligands
Tell me 3 things about MHC education.
NK cells detect specific MHC I isotype
NK cells MUST detect that specific MHC I
NK cells ONLY detect that specific MHC I
HLA- A, B, C receptors?
T and NK cell receptors
HLA-E, G receptors?
NK cells
HLA-F receptors?
Intracellular chaperone
NK cells have activation and effector responses. Tell me the 3 activation responses.
1 - Target Cell Interaction
- Downregged MHC I
- Stress ligands
- CD16
2 - Leukocyte interactions
- Antigen presenting cells
- Th cells
- NKT cells
3 - Cytokines
- IFNs, IL-12
- Proliferation, Receptor expression, cytokine and granule production
What are the 2 effector fxs of NK cells?
Cytokine release
Cytotoxicity
Tell me how the NK cells are activated in the innate system.
- 2 activating signals needed
- MHC surveillance
- Stress ligands
Tell me how NK cells are activated in the adaptive system.
-SINGLE signal
—Fc receptor
-Ig targeting
CD 4 cells interact with what MHC?
MHC II
CD 8 and NK cells interact with what MHC?
MHC I
In what 3 ways are NK cells cytotoxic?
1 - Degranulation
—Perforins - Cause holes
—Granzymes - Proteases thru holes - Induce apoptosis
—Work the same way as CD8
2 - Death-receptors
—FasLigand
—TRAIL
3 - Interferons and NO
What to gamma:delta cells do?
Remove diseased and malignant cells
-Monitor tissue health
They sit in the mucosal epithelial layer and monitor the situations
What unique antigens do gamma:delta bind?
Phosphoantigens
Phospholipids
Lipids
Gamma:Delta cells have a similar activity as?
Both CD8 and CD4
CD8
- Directly kill
- Cytokine and chemokine release
CD4
-NK, macrophage, and DC activation
Gamma:delta cells express ________ ligand receptors that can help to detect the presence and absence of MHC I.
Stress
-Promote tissue repair and homeostasis
CD1 expresses self and non-self ________.
LIPIDS
Exquisite specificity
Gamma:delta cell receptors interact with ______.
CD1
- Discriminate self vs non-self
- Activation, potential targeted killing
- Co-signal dependent
What 3 things do gamma:delta receptors bind?
Phospholipid receptors
MHC I-related receptors
Stress ligands
T/F - Gamma:delta cells have a rapid response to local pathogens and disease.
TRUE
- PAMPs
- Stress ligands
Do gamma:delta cells promote inflammation?
YOU BET THEY DO!
- Th17 and Th1 activation
- NK activation
T/F - gamma:delta cells drive adaptive initiation.
TRUE
- DC and macrophage stimulation
- Direct presentation
T/F - Gamma:delta cells are directly cytotoxic.
TRUE
- Perforin and granzymes
- CD16
