Summer Immuno Lecture 6 Flashcards

A viral infection activates cytotoxic T cells, and a bacterial infection activates helper T cells. Once these T cells begin performing their immune functions, what are they called?

_____ _____

A helper T-cell clone produces IL-4 and IL-5 but not IFN-gamma or IL-17. What best explains this finding?
A. Subset-restricted cytokine programs
B. Uniform cytokine secretion
C. Antibody class deletion
D. TCR chain editing

Effector helper T cells are classically divided into which three major cytokine-producing groups?

A cell samples microbial products, reads local cytokine signals, and determines how helper T cells should respond. Which cell is being described?

A dendritic cell detects both microbial motifs and local soluble immune signals. Which two input systems is it integrating?
A. MHC and TCRs
B. Fc and complement receptors
C. PRRs and cytokine receptors
D. BCRs and integrins

Skin cells near an infection release a characteristic mixture of signals that helps dendritic cells identify the attack location. What are these signals?

_______

An activated dendritic cell instructs a helper T cell how to respond. Which output best conveys this plan?
A. Antibody and complement
B. Histamine and leukotrienes
C. Perforin and granzyme
D. Co-stimulation and cytokines

A dendritic cell leaves infected intestinal tissue and primes a helper T cell. Its instructions mainly reflect what prior information?
A. T-cell receptor affinity
B. Local tissue immune signals
C. Bone marrow stromal signals
D. Plasma antibody concentration

A patient with gram-negative sepsis has macrophage activation after recognition of LPS. Which receptor is most directly involved?

A dendritic cell detects molecules from gram-positive bacteria. Which Toll-like receptor is classically involved?

During a viral infection, dendritic cells detect double-stranded RNA produced during replication. Which receptor recognizes it?

During a viral infection, dendritic cells detect single-stranded RNA produced during replication. Which receptor recognizes it?

A dendritic cell detects unmethylated CpG DNA during infection. Which receptor is most associated with this pattern?

Unmethylated CpG dinucleotides are detected by innate immune cells. This pattern most strongly suggests which source?
A. Bacterial DNA
B. Viral envelope
C. Fungal capsule
D. Helminth cuticle

A dendritic cell presents antigen plus IL-12 to a virgin helper T cell. Which helper subset is most likely induced?

Which cytokine trio best matches the classical Th1 profile?

A Th1 response helps activate macrophages and natural killer cells early in infection. Which cytokine performs this function?

A macrophage has already been activated during intracellular infection. Which Th1 cytokine helps keep it activated?

A patient needs B-cell class switching toward human IgG3 during a Th1 response. Which cytokine provides this influence?

A cytokine keeps NK cells “charged up” and promotes proliferation of CTLs, NK cells, and Th1 cells. Which cytokine is this?

Tissue invasion by a parasite causes activated dendritic cells to polarize helper T cells toward which cytokine subset?

Which 5 cytokines best matches the Th2 subset?

A Th2 cytokine acts as a growth factor for helper T cells already secreting Th2 cytokines. Which cytokine is it?

A mucosal immune response encourages B cells to produce IgA antibodies. Which Th2 cytokine is responsible?

A helminth-associated immune response promotes B-cell class switching toward IgE. Which cytokine most directly supports this?

During intestinal parasite defense, goblet-cell mucus production increases. Which cytokine best explains this effect?

Fungi attack a mucosal barrier. Activated dendritic cells produce TGF-beta plus IL-6. Which helper subset is favored?

Which cytokine trio best matches the Th17 subset in this material?

A growth factor expands helper T cells producing the Th17 cytokine subset. Which cytokine is this?

A mucosal fungal infection triggers recruitment of massive numbers of neutrophils. Which cytokine is most responsible?

B cells guarding mucosal surfaces begin producing IgG3 and IgA. Which Th17 cytokine caused this shift?

A dendritic cell tells a helper T cell where to migrate but gives no clear effector instructions. What subset results?
A. Th1
B. Th0
C. Th2
D. Th17

A helper T cell retains the ability to produce a broad range of cytokines after incomplete dendritic-cell instruction. What is this called?
A. Th2 polarization
B. Th1 commitment
C. Th17 maturation
D. Th0 subset

A Th0 cell reaches infected tissue and encounters cytokines specific to that site. What happens next?
A. It adopts a relevant subset
B. It becomes permanently anergic
C. It deletes its TCR
D. It stops cytokine secretion

A researcher finds helper T cells that do not fit neatly into Th1, Th2, or Th17 categories. What is the best interpretation?
A. All T cells are mislabeled
B. Only CTLs make cytokines
C. The paradigm has exceptions
D. Dendritic cells lack cytokines

A Th1-polarized response becomes dominant during infection. Which cytokine helps suppress proliferation of competing Th2 cells?

A Th2 response is limiting excessive Th1 expansion. Which cytokine most directly mediates this inhibition?

Why do Th helper subsets inhibit one another?
A. To increase antibody diversity
B. To prevent competing activation
C. To destroy infected cells
D. To increase cytokine range

What is a cytokine property?
A. Limited local range
B. Permanent receptor binding
C. Systemic endocrine spread
D. Antigen-specific recognition

A patient receives intradermal tuberculin and returns days later for evaluation. What immune phenomenon is being tested?
A. Type I hypersensitivity
B. Immune-complex disease
C. Delayed-type IV hypersensitivity
D. Complement-mediated lysis

The tuberculosis skin test requires waiting several days after tuberculin injection. This delay best reflects which process?
A. T cell-mediated inflammation
B. Immediate mast-cell degranulation
C. IgE-mediated wheal formation
D. Direct bacterial toxin injury

A cytotoxic T lymphocyte kills a virus-infected epithelial cell by delivering enzymes into the target cell. Which pair is most involved?
A. FasL and IL-10
B. Perforin and granzyme B
C. IFN-gamma and IL-4
D. IL-17 and IL-23

A CTL releases a molecule that disrupts the target cell membrane, allowing entry of apoptotic enzymes. Which molecule does this?

A CTL delivers an enzyme into an infected target cell, triggering apoptosis. Which molecule is responsible?

A cytotoxic T cell uses a death-receptor pathway instead of granule exocytosis. Which molecule on the CTL is responsible?

_____ _____

Fas ligand on a CTL triggers apoptosis by binding which target-cell structure?

_____ _____

A CTL secretes IFN-gamma near infected cells. What is the main local effect?
A. Decrease class II MHC
B. Increase class I MHC
C. Suppress Fas expression
D. Block granzyme uptake

Why does CTL-derived IFN-gamma help future CTL recognition?
A. It increases IgE switching
B. It recruits eosinophils locally
C. It raises MHC I expression
D. It suppresses viral apoptosis

A virus-infected cell is killed by apoptosis rather than necrosis. Why is apoptosis safer locally?
A. Less surrounding tissue damage
B. More enzyme leakage occurs
C. More complement activation occurs
D. Greater neutrophil rupture occurs

Necrosis of an infected cell can worsen nearby injury because it releases which contents?
A. Antibodies and cytokines
B. MHC and TCRs
C. Enzymes and chemicals
D. Perforin and FasL

A CTL induces apoptosis in a virus-infected cell before viral assembly is complete. What benefit does this provide?

Destroys viral ______ ______

A cytotoxic T cell uses three major weapons against infected host cells. Which set is most complete?
A. IL-4, IL-5, IL-13
B. TLR2, TLR3, TLR9
C. Perforin, FasL, IFN-gamma
D. IgA, IgE, IgG3

Which set of helper T cells help to attack fungi or extracellular bacteria?

produced by Th1 helper t-cells, will stimulate prolonged activity of NK Cells after 16 hours

stimulates macrophage activation and prolonged activity & stimulates b-cell class switching to produce IgG3

What cell conveys "gameplan" to the helper T cell?

What subset would be activated if you have a puncture wound that results in a bacterial infection or if you are attacked by a virus that replicates in the tissues?

What subset would be activated if you have been infected by a parasite (e.g., hook worms) or you have eaten some food that is contaminated with pathogenic bacteria?

Th2 are induced by ______ and ______

What cytokine stimulates the production of mucus in the intestine?

TH17 Cells are induced by ______, ______, ______

What cytokine can cause B cells that guard the mucosal surfaces to produce IgG3 and IgA antibodies.

Once a Killer T cell has been activated and mobilized to the sight of attack

First way of killing
1. ______ is a close relative of MAC which will punch holes in the membrane
2. ______ will induce apoptosis

2nd Way
A killer T cell can use a fas ligand which can bind to Fas and induce ______