Unit 5 Question Bank
The five tabs are the five sections of the real paper. Items tagged
Past Paper 2019 or 2020 are the genuine questions, reproduced verbatim.
Items tagged Slide come from the TMU lecture; items tagged Janeway's are built
from the textbook to cover examinable ground. Nothing is invented. Janeway's 10e is a reflowed
edition with no printed page numbers, so it is cited by numbered section (§1-14), not by page.
0 / 29 answered
1Which of the following does not belong to the properties of cytokines?
Answer: C
Specificity. The five cytokine attributes are pleiotropism, redundancy, synergy, antagonism and cascade induction. Specificity belongs to the antigen receptors — TCR, BCR and antibody. Cytokines are the opposite of specific: one cytokine does many things (pleiotropism) and many cytokines do the same thing (redundancy).Past Papers 2019 & 2020, Section III Q15 — verbatim, both years
2Cytokines secreted by Th2 cells include:
Answer: D
IL-4, IL-5, IL-10 (with IL-6 and IL-13) is the Th2 profile — and Th2 makes neither IL-2 nor IFN-γ. IL-2, IFN-γ and TNF are Th1. IL-1, IL-12 and TNF drive antibacterial innate immunity; IFN-α/β are the antiviral type I interferons. ⭐ This is the content behind the one True/False item that changes between the two papers.TMU Lecture 7 — Immune Cells Slide 139 · Past Paper 2020, Section IV Q3
3Cytokines secreted by Th1 cells include:
Answer: A
IL-2, IFN-γ and TNF, and specifically not IL-4. TMU's slide writes the third as TNF-α; the circulated student sheets write TNF-β; Janeway's shows Th1 cells release both TNF-α and lymphotoxin (which is TNF-β). Write TNF, or TNF-α if a form is demanded — that is your department's own wording.Past Paper 2020, Section II Q7 · TMU Lecture 7 — Immune Cells Slide 139
4Which cytokine drives the differentiation of Th0 into Th2 cells?
Answer: B
IL-4 drives Th0 → Th2. IL-12 and IFN-γ drive Th0 → Th1. Note the self-reinforcing design: each lineage secretes the very cytokine that drives its own differentiation and inhibits the other, so the commitment locks itself in.TMU Lecture 7 — Immune Cells Slide 144
5A single cytokine mediating several different biological effects on different target cells is called:
Answer: C
Pleiotropism — one cytokine, many effects. Its mirror image is redundancy: many cytokines, one effect. Together they are why the cytokine network cannot be specific, and why blocking a single cytokine therapeutically so often disappoints — something else covers for it.TMU Lecture 5 (Juan Li) Slide 14
6Two cytokines interacting to produce an effect greater than expected from either alone is called:
Answer: D
Synergy. Its opposite is antagonism, where two cytokines oppose each other's action — as IFN-γ and IL-4 do across the Th1/Th2 divide.TMU Lecture 5 (Juan Li) Slide 16
7A cytokine acting on the very cell that secreted it is acting in which manner?
Answer: A
Autocrine — the classic example being a T cell that makes IL-2 and drives its own proliferation. Paracrine (on a nearby cell) is the commonest mode; endocrine action through the circulation is how a local infection produces systemic fever.TMU Lecture 5 (Juan Li) Slide 12
8Which statement about cytokine secretion is correct?
Answer: B
Cytokine secretion is a brief, self-limited event — nothing is stockpiled, so a cell that needs a cytokine must transcribe it. Synthesis is also promiscuous both ways: IL-6 comes from macrophages, endothelium and T cells, while a single Th cell makes IL-2, IL-4, IL-5, IL-10 and IFN-γ.TMU Lecture 5 (Juan Li) Slide 10
9Type I interferons are:
Answer: C
Type I = IFN-α and IFN-β, the antiviral interferons made by dendritic cells and infected cells. Type II = IFN-γ, made by activated T and NK cells, and it is principally an immune-activating molecule — Janeway's calls it the principal macrophage-activating cytokine.TMU Lecture 5 (Juan Li) Slide 20
10Chemokines are classified into CXC, CC, C and CX3C families on the basis of:
Answer: D
The letters read out the structure directly: C is cysteine and X is any amino acid. CC = two adjacent cysteines; CXC = one residue between them; CX3C = three residues between; C = a single cysteine. The name is a structural description, not a list to memorise.TMU Lecture 5 (Juan Li) Slide 26
11Which cytokines principally mediate antiviral innate immunity?
Answer: A
Type I interferons — the clue is in the name, since interferon was defined by its ability to interfere with viral replication. IL-1, TNF and IL-12 handle antibacterial innate immunity; IL-2/IL-4/IL-5 regulate adaptive immunity; CSF, EPO and TPO stimulate haematopoiesis.TMU Lecture 5 (Juan Li) Slide 27
12Which set of cytokines stimulates haematopoiesis?
Answer: B
The colony-stimulating factors together with IL-7, erythropoietin, IL-6, IL-11 and thrombopoietin. Again the class name gives it away — a colony-stimulating factor stimulates formation of cell colonies in bone marrow.TMU Lecture 5 (Juan Li) Slides 21, 27
13A soluble cytokine receptor (sCKR) functions by:
Answer: C
It is a decoy — the binding site with no cell attached, so anything it captures is neutralised before it reaches a cell-bound receptor. The drug etanercept (a soluble TNF receptor fused to Fc, used in rheumatoid arthritis) is a manufactured version of this natural mechanism.TMU Lecture 5 (Juan Li) Slide 32
14How many families of cytokine receptor are described?
Answer: D
Five families. Note that the Ig superfamily appears here as well — the same Ig fold you met in Unit 3, which also builds TCR, MHC, CD4, CD8, B7 and ICAM.TMU Lecture 5 (Juan Li) Slide 30
15Cytokine storm is best defined as:
Answer: A
Its typical features are increased capillary permeability with loss of blood pressure and shock, sometimes fatal. It is a failure of the containment described earlier: secretion stops being brief, local and self-limited and becomes systemic and self-amplifying — cascade induction with no brake.TMU Lecture 5 (Juan Li) Slides 33–34
16Which of the following is a correct contrast between cytokines and hormones?
Answer: B
Both are secreted messengers acting through high-affinity receptors, but a cytokine acts locally (usually paracrine or autocrine) while a hormone usually acts at a distance. Cytokines differ from growth factors in the other direction: growth factors are made constitutively, cytokine production is carefully regulated.TMU Lecture 5 (Juan Li) Slide 5
1 Cytokine (CK) — 3 marks+
Any of numerous secreted, low-molecular-weight proteins that regulate the intensity and duration of the immune response by exerting a variety of effects on lymphocytes and other immune cells that express the appropriate receptor. Cytokines act locally (autocrine or paracrine) rather than at a distance, are not stored preformed, and play a role in both innate and adaptive immunity. ⭐ Set as a Section I definition in BOTH the 2019 and 2020 papers.Past Paper 2019, Section I Q3 and Past Paper 2020, Section I Q3 · TMU Lecture 5 (Juan Li) Slide 7
2 Attributes of cytokines — 3 marks+
Pleiotropism — one cytokine mediates diverse effects on different target cells. Redundancy — several cytokines mediate the same effect. Synergy — two cytokines together produce a greater effect than either alone. Antagonism — two cytokines oppose each other. Cascade induction — one cytokine induces others, which then mediate its biological effect. Cytokines notably do NOT possess specificity.TMU Lecture 5 (Juan Li) Slides 14, 16
3 Autocrine, paracrine and endocrine action — 3 marks+
Autocrine — the cytokine acts on the same cell that secreted it. Paracrine — it acts on a nearby cell; this is the usual mode. Endocrine — it enters the circulation and acts at a distance from the site of production.TMU Lecture 5 (Juan Li) Slide 12
4 Interferon (IFN) — 3 marks+
A class of cytokine that interferes with viral infection and replication. Type I comprises IFN-α and IFN-β, produced by dendritic cells and infected cells, and is the antiviral arm. Type II is IFN-γ, produced by activated T cells and NK cells, and acts principally to activate macrophages.TMU Lecture 5 (Juan Li) Slide 20
5 Chemokine — 3 marks+
A large family of structurally homologous cytokines that stimulate leukocyte movement and regulate the migration of leukocytes from the blood into tissues. Classified by primary structure into CXC, CC, C and CX3C families, where C is cysteine and X is any amino acid — the letters describe the spacing of the first two cysteines.TMU Lecture 5 (Juan Li) Slides 24, 26
6 Th1 and Th2 cells — 3 marks+
The two effector lineages of CD4⁺ helper T cells, arising from Th0. Th1 produces IL-2, IFN-γ and TNF (not IL-4), promotes cellular immunity by activating macrophages, NK cells and CTL, and participates in type IV hypersensitivity. Th2 secretes IL-4, IL-5, IL-6, IL-10, IL-13 (not IL-2 or IFN-γ), promotes humoral immunity and class switching to IgG1 and IgE, and participates in type I hypersensitivity and defence against parasites. IL-12 + IFN-γ drive Th1; IL-4 drives Th2.TMU Lecture 7 — Immune Cells Slides 139–144
7 Soluble cytokine receptor (sCKR) — 3 marks+
A cytokine receptor that has detached from the cell membrane to circulate in solution, where it competitively antagonises the effect of its cytokine by binding it before it can reach a cell-bound receptor. The drug etanercept — a soluble TNF receptor fused to an Fc fragment — is a therapeutic application of this principle.TMU Lecture 5 (Juan Li) Slide 32
8 Cytokine storm — 3 marks+
The pathological secretion of extremely high levels of cytokines, induced by massive infection with particular pathogens. Typical features include increased capillary permeability with resultant loss of blood pressure and shock, sometimes leading to death; also clotting, renal failure, lung injury, cell death and immune paralysis.TMU Lecture 5 (Juan Li) Slides 33–34
1Cytokines secreted by Th1 cells include ? , ? and ? .3 mark(s)
⚠️ IFN-γ and IL-2 are beyond doubt. For the third, TMU Lecture 7 slide 139 writes TNF-α, the circulated student sheets write TNF-β, and Janeway's shows Th1 cells release both TNF-α and lymphotoxin (which is TNF-β). Write TNF, or TNF-α if a specific form is required — that is your department's own wording.
Past Paper 2020, Section II Q7 · TMU Lecture 7 — Immune Cells Slide 1392Cytokines secreted by Th2 cells include ? , ? and ? .3 mark(s)
Also IL-6 and IL-13. Th2 makes neither IL-2 nor IFN-γ. This exact set is what makes the True/False trap work — IL-4, IL-5, IL-10 is a Th2 profile, so the 2019 statement attributing it to Th1 is false and the 2020 statement attributing it to Th2 is true.
TMU Lecture 7 — Immune Cells Slide 1393The five attributes of cytokines are ? , ? , ? , ? and ? .5 mark(s)
Cytokines notably do not possess specificity — that is the property MCQ Q15 asks about.
TMU Lecture 5 (Juan Li) Slides 14, 164Cytokines may act in three ways: ? action on the same cell, ? action on a nearby cell, and ? action at a distance through the circulation.3 mark(s)
Paracrine is the usual mode, which is why cytokines are described as acting locally in contrast to hormones.
TMU Lecture 5 (Juan Li) Slide 125Type I interferons are ? and ? ; type II interferon is ? .3 mark(s)
Type I is produced by dendritic cells and infected cells and is antiviral; type II is produced by activated T cells and NK cells and mainly activates macrophages.
TMU Lecture 5 (Juan Li) Slide 206Differentiation of Th0 into Th1 is induced by ? and ? , while differentiation into Th2 is induced by ? .3 mark(s)
Each lineage then secretes the cytokine that drives its own differentiation and inhibits the other, so the commitment becomes self-locking.
TMU Lecture 7 — Immune Cells Slide 1447The six classes of cytokine are ? , ? , ? , ? , ? and ? .6 mark(s)
The interleukins now run from IL-1 to IL-39. Each class name states its original defining function, which is why the biological-activity table can largely be reconstructed from the class names.
TMU Lecture 5 (Juan Li) Slides 20–241Cytokines secreted by Th1 cells include IL-4, IL-5, IL-10. (2019 wording)
FALSE
FALSE. IL-4, IL-5 and IL-10 are the Th2 profile. Th1 secretes IL-2, IFN-γ and TNF. ⭐ In the 2020 paper the same sentence appears with Th2 in place of Th1 — and the answer becomes TRUE. This is the only item on the entire paper whose answer changes between the two years.Past Paper 2019, Section IV Q3
2Cytokines secreted by Th2 cells include IL-4, IL-5, IL-10. (2020 wording)
TRUE
TRUE — the Th2 profile, along with IL-6 and IL-13. Compare with the statement above: one word changed and the correct answer inverted. Anyone who memorised the 2019 key without learning the profiles scores 11 out of 12 and never finds out why.Past Paper 2020, Section IV Q3
3Specificity is one of the defining attributes of cytokines.
FALSE
False. The five attributes are pleiotropism, redundancy, synergy, antagonism and cascade induction. Specificity belongs to the antigen receptors. Pleiotropism and redundancy between them make specificity structurally impossible: one cytokine does many things, and many cytokines do the same thing.Past Papers 2019 & 2020, Section III Q15 · TMU Lecture 5 (Juan Li) Slide 14
4Cytokines are stored in granules as preformed molecules ready for rapid release.
FALSE
False. Cytokine secretion is a brief, self-limited event: they are not stored preformed, but synthesised on demand and secreted immediately. This is why cytokine effects are normally confined in time as well as in space.TMU Lecture 5 (Juan Li) Slide 10
5One cytokine can be produced by several different cell types.
TRUE
True — IL-6 is made by macrophages, endothelial cells and T cells alike. The converse is also true: one Th cell makes IL-2, IL-4, IL-5, IL-10 and IFN-γ. This promiscuity is precisely why the older names (monokine, lymphokine) were abandoned in favour of classification by function.TMU Lecture 5 (Juan Li) Slide 10
6IFN-γ is a type I interferon produced by infected cells.
FALSE
False. IFN-γ is type II, produced by activated T cells and NK cells, and acts mainly to activate macrophages. Type I is IFN-α and IFN-β, produced by dendritic cells and infected cells, and is the antiviral arm.TMU Lecture 5 (Juan Li) Slide 20
1
Describe the general characteristics (attributes) of cytokines.
6 marks
Secretion. A brief, self-limited event — cytokines are not stored preformed but synthesised and immediately secreted.
Synthesis. Different cell types make the same cytokine (IL-6 from macrophages, endothelium and T cells); one cell type makes many cytokines.
Action. Through high-affinity receptors on target cells, in three modes: autocrine (same cell), paracrine (nearby cell) and endocrine (at a distance).
| Attribute | Meaning |
|---|---|
| Pleiotropism | One cytokine, diverse effects on different target cells |
| Redundancy | Several cytokines, the same effect |
| Synergy | Two cytokines together exceed the sum of their separate effects |
| Antagonism | Two cytokines oppose each other |
| Cascade induction | One cytokine induces others, which mediate its effect |
Cytokines do not possess specificity — stating this explicitly is worth a mark, and it is what MCQ Q15 tests.
Marking guide: 1 mark per attribute (5) plus 1 for the modes of action or the non-storage/receptor points. Explicitly noting the absence of specificity distinguishes a complete answer.
2
Compare Th1 and Th2 cells.
6 marks
| Th1 | Th2 | |
|---|---|---|
| Cytokines produced | IL-2, IFN-γ, TNF — not IL-4 | IL-4, IL-5, IL-6, IL-10, IL-13 — not IL-2 or IFN-γ |
| Induced by | IL-12 and IFN-γ | IL-4 |
| Promotes | Cellular immunity | Humoral immunity |
| Main effect | Activates macrophages for intracellular killing; promotes NK function and CTL proliferation and differentiation | Activates B cells for proliferation, differentiation and antibody production; activates eosinophils |
| Antibody class helped | IgG2a | IgG1 and IgE |
| Hypersensitivity | Type IV | Type I |
| Also | Certain autoimmune diseases | Defence against parasites |
Worth adding: each lineage's cytokines inhibit the other lineage (IFN-γ suppresses Th2; IL-4 and IL-10 suppress Th1), so the commitment is self-reinforcing.
Marking guide: 1 mark per row. The cytokine row and the cellular-vs-humoral row carry the most weight — an answer that reverses them cannot pass, and it is exactly the error the True/False question is designed to catch.
3
Classify the cytokines and give the principal biological activity of each class.
6 marks
| Class | Activity | Members |
|---|---|---|
| Interleukin (IL) | Made by leukocytes, acting on leukocytes | IL-1 to IL-39 |
| Interferon (IFN) | Interferes with viral infection and replication | Type I: IFN-α, IFN-β · Type II: IFN-γ |
| TNF | Necrosis of tumour cells; promotes inflammation | TNF-α, TNF-β (lymphotoxin) |
| CSF | Stimulates colony formation in bone marrow | GM-CSF, M-CSF, G-CSF |
| Growth factor | Stimulates cell growth and proliferation | NGF, EGF, VEGF, FGF, PDGF |
| Chemokine | Stimulates leukocyte movement; regulates migration from blood into tissue | CXC, CC, C, CX3C |
General activities: innate antibacterial — IL-1, TNF, IL-12; innate antiviral — IFN-α, IFN-β; adaptive — IL-2, IL-4, IL-5, IL-6, IFN-γ; haematopoiesis — CSF, IL-7, EPO, IL-6, IL-11, TPO.
Marking guide: 1 mark per class named with its activity. Adding the four general-activity groupings secures full marks.