Summer Immuno Lecture 8 Flashcards

Neutrophils have a typical half-life of approximately what duration?
A. 30 minutes
B. 6 weeks
C. 20 days
D. A few days

Inducible regulatory T cells arise from which precursor population?

____ ____ cells

Which cytokine-rich environment favors inducible Treg formation?
A. IL-2 rich
B. IL-12 rich
C. IFN-gamma rich
D. TGF-beta rich

iTregs are considered regulatory because they produce cytokines that do what?

____ ____ responses

Which cytokine pair is classically produced by iTregs in this material?

_____ binds receptors on APCs and reduces expression of Pattern Recognition Receptors (PRRs).

A macrophage exposed to IL-10 becomes harder to activate. Which mechanism best explains this?

Reduced ____ expression

IL-10 binding to APCs also reduces which co-stimulatory molecule family?

____

A patient overproduces IL-10 during infection. Which APC change would most impair naive T-cell activation?

Reduced ____ expression

TGF-beta dampens T-cell responses by reducing which T-cell property?

____ ____

TGF-beta reduces the effectiveness of which effector lymphocyte group?

___ ___ cells

As an immune battle is won, immune activation decreases partly because less of what remains?
A. Host MHC
B. Foreign antigen
C. Plasma antibody
D. Naive lymphocytes

Reduced foreign antigen after pathogen clearance decreases activation of which systems?
A. Coagulation and fibrinolysis
B. Complement and clotting
C. Platelets and endothelium
D. Innate and adaptive

Naive T cells keep _____ stored inside the _____ before activation.

After the T cell is activated, _____ moves to the surface and helps turn down T-cell activation

After activation, CTLA-4 begins moving to the T-cell surface after approximately how long?
A. 30 minutes
B. 6 weeks
C. 2 days
D. 1 week

B7 proteins on APCs bind which inhibitory receptor with very high affinity.

Compared with CD28, B7 has approximately how much greater affinity for CTLA-4?
A. 1000-fold
B. 10-fold
C. 2-fold
D. Equal affinity

CTLA-4 dampens T-cell activation by outcompeting which activation receptor?

Early in naive T-cell activation, B7 binding to CD28 primarily provides what signal?
A. Apoptotic signal
B. Trafficking signal
C. Activation signal
D. Antibody signal

As CTLA-4 increases on the T-cell surface, the T cell becomes progressively what?
A. More cytotoxic
B. Less activated
C. More chemotactic
D. Less antigen-specific

Shortly after T-cell activation, another inhibitory receptor is upregulated. Which receptor is this?
A. PD-1
B. PD-L1
C. CD40
D. GlyCAM-1

The ligand for PD-1 is which molecule?
A. CD28
B. B7
C. PD-L1
D. FasL

PD-L1 appears on the surface of which tissues?

____ tissues

PD-L1 restrains activated T cells that have been working for what duration?
A. Before antigen exposure
B. For some time
C. Only minutes
D. Since thymic selection

CTLA-4 and PD-1 are collectively called what?
A. Checkpoint proteins
B. Chemokine receptors
C. Adhesion molecules
D. Pattern receptors

Checkpoint proteins help do what as an immune battle winds down?
A. Activate naive T cells
B. Recruit neutrophils
C. Crosslink BCRs
D. Decommission T cells

Immune weapons help ramp down quickly after victory because many have what property?
A. Short half-lives
B. Permanent activation
C. Long telomeres
D. High antigen affinity

NK cells have a typical half-life of approximately what duration?
A. A few hours
B. 1 week
C. 6 weeks
D. 2 days

Activated macrophages are maintained by IFN-gamma produced mainly by which cells here?

___ cells

When NK cells die off, activated macrophages tend to do what?

Dendritic cells live approximately how long after reaching a lymph node?

Plasma B cells die off after approximately how long of labor?

T cells require a special shutdown pathway partly because they naturally have what property?

____ ____

The natural apoptosis pathway limiting repeatedly activated T cells is called what?
A. AICD
B. ADCC
C. DTH
D. MALT

AICD stands for which process?
A. Antigen-independent clonal division
B. Adaptive immune cell deletion
C. Antibody-induced complement destruction
D. Activation-induced cell death

CTLs express which ligand that binds death receptors on target cells?
A. CD40L
B. Fas ligand
C. PD-L1
D. ICOSL

Fas ligand on CTLs plugs into which receptor on target cells?
A. CD28
B. CTLA-4
C. Fas
D. B7

Virgin T cells are initially how responsive to Fas self-ligation?
A. Highly sensitive
B. Partially cytotoxic
C. Permanently apoptotic
D. Insensitive

After repeated activation and reactivation, T cells become more sensitive to what?
A. Fas self-ligation
B. BCR crosslinking
C. Complement opsonization
D. CXCL13 migration

A repeatedly activated T cell dies when its own FasL binds its own Fas receptor. What process is this?

_____-_____ apoptosis

A repeatedly activated T cell is killed when FasL on another T cell binds its Fas receptor. Which pathway is involved?
A. PD-1 blockade
B. CTLA-4 competition
C. Fas-mediated AICD
D. B7-mediated priming

Once an invader is destroyed, approximately what fraction of responding T cells die off?
A. More than 90%
B. About 5%
C. Nearly 50%
D. Less than 10%

Which molecule most directly reduces APC co-stimulation?
A. IL-10
B. IL-2
C. IL-17
D. IFN-gamma

Which molecule most directly reduces T-cell proliferation?
A. TNF
B. IL-4
C. TGF-beta
D. IL-5