Interleukins

INTERLEUKINS

Q. 1

Which of the interleukins is responsible for endogenous pyrexia in a young lady admitted on the medical ward?

 A

IL1

 B

IL6

 C

INF gamma

 D

IFN alpha

Q. 1

Which of the interleukins is responsible for endogenous pyrexia in a young lady admitted on the medical ward?

 A

IL1

 B

IL6

 C

INF gamma

 D

IFN alpha

Ans. A

Explanation:

IL1 also konwn as endogenous pyrogen causes fever by inducing the production of prostaglandin E2 which acts on the hypothalamus and induce a fever like reaction.

IL 1 is produced by macrophages.


Q. 2

The genetic defect associated with decreased response to interferon therapy to Hepatitis C is:

 A

IL28B

 B

IL15

 C

c-KIT

 D

NAT2

Q. 2

The genetic defect associated with decreased response to interferon therapy to Hepatitis C is:

 A

IL28B

 B

IL15

 C

c-KIT

 D

NAT2

Ans. A

Explanation:

Some patients with hepatitis C may not respond well to treatment with interferon as expected. They are harboring genetic variation in IL28B usually.

Ref: Harrison, Edition-18, Page-42


Q. 3

Interleukin – 7 is produced by which one of the following –

 A

Macrophage

 B

B cells

 C

T cells

 D

Stromal cells

Q. 3

Interleukin – 7 is produced by which one of the following –

 A

Macrophage

 B

B cells

 C

T cells

 D

Stromal cells

Ans. D

Explanation:

Ans. is `d’ i.e., Stromal cells

.       IL-7 is produced by spleen and bone marrow stromal cells.

.       It acts as B and T cell growth factor.


Q. 4

Interleukin responsible for pyrexia is?

 A

ILI

 B

IL6

 C

INF gamma

 D

a and b

Q. 4

Interleukin responsible for pyrexia is?

 A

ILI

 B

IL6

 C

INF gamma

 D

a and b

Ans. D

Explanation:

Ans. is ‘a > b’ i.e., IL1 > IL6


Q. 5

The following interleukin is characteristically produced in a TH1 response –

 A

IL-2

 B

IL -4

 C

IL-5

 D

IL-10

Q. 5

The following interleukin is characteristically produced in a TH1 response –

 A

IL-2

 B

IL -4

 C

IL-5

 D

IL-10

Ans. A

Explanation:

Ans. is ‘a i.e., IL-2

A.T helper —1 (TH‘) secretes          –> IL-2 and interferon –

B. T helper — 2 (TH2) secretes            —> IL-4, IL-5, IL-6, IL-13

Also know

T-cell receptor (TCR)

o The T cell receptor is a molecule found on T cells that is responsible for recognizing antigens bound to MHC molecules.

o TCR of CD4 T cells recognises the antigens bound to MHC class II.

o TCR of CDs T cells recognises the antigens bound to MHC class I.

o TCR is a heterodimer made up of an a and a 3 chain (TCR a fi) in 95% of cases, and a y and a 8 chain in 5% of cases (TCR 1,5).

o TCR 78 binds to antigens without MHC involvement.

o TCR a.I3 recognises antigens presented on MHC molecule of antigen presenting cells.

o There are also some accessory molecules associated with TCR CD, and ‘C’ proteins.

o These accessory molecules do not bind to antigen, but involve in signal transduction after TCR has bound to antigen.

o TCR diversity is generated by somatic rearrangements of the genes that encode TCR.

o Rearrangement of these genes occur only in T-cell during their development in thymus; hence the presence of TCR gene rearrangements demonstrated by molecular analysis is marker of T-lineage cells. TCR Co-receptors

o The signal from the T-cell complex is enhanced by simulataneous binding of the MHC molecules by a specific co-receptor.

o On helper T cell, this co-receptor is CD4 that exclusively binds to the class II MHC on antigen presenting cells. o On cytotoxic T cell, this co-receptor is CD8 that is specific for class I MHC on antigen presenting cells.

o The Co-receptor not only ensures the specificity of the TCR for the correctly – presented antigen but also allows

prolonged engagement between antigen presenting cells and the T-cell.

TCR costimulator

o Beside TCR, MHC, CD4/CDs interaction there is another molecule on T cell that activate the T-cell—> costimulator. o It is CD-28 on the surface of T cells that interact with B7-1 (CD-80) and B7-2 (CD-86) expressed on antigen presenting cells.

o So, for activation of T-cells, two signals are required

o Signal 1 —> via TCR by TCR, MHC, CD4/CD8 interactions.

o Signal 2 –> CD-28, B7-1 / B7-2 interaction.


Q. 6

Interleukin secreted by macrophages, stimulating lymphocytes is –

 A

INF alpha

 B

TNF alpha

 C

IL-1

 D

IL-6

Q. 6

Interleukin secreted by macrophages, stimulating lymphocytes is –

 A

INF alpha

 B

TNF alpha

 C

IL-1

 D

IL-6

Ans. C

Explanation:

 

Interleukin -I

o Also known as leucocyte activating factor (LAF) or B cell activating factor (BAF).

  • Mainly secreted by macrophages and monocytes; and epithelial cells.
  • Other sources are B-lymphocytes, fibroblasts and Endothelial cells.

o Immunological effects of IL-1

  • Activation of T cells for the production of IL – 2.
  • B cell proliferation and antibody synthesis
  • Neutrophil chemotaxis and increased PMN release from bone marrow.
  •  Increases body temperature (important endogenous pyrogen).
  •  Bone marrow cell proliferation
  • Induction of acute phase protein.

Q. 7

Mast cells release interleukin –

 A

1

 B

2

 C

4

 D

All

Q. 7

Mast cells release interleukin –

 A

1

 B

2

 C

4

 D

All

Ans. D

Explanation:

All are true


Q. 8

Which interleukin is needed for differentiation of eosinophils:

September 2009

 A

IL1

 B

IL2

 C

IL4

 D

IL5

Q. 8

Which interleukin is needed for differentiation of eosinophils:

September 2009

 A

IL1

 B

IL2

 C

IL4

 D

IL5

Ans. D

Explanation:

Ans. D: IL5


Q. 9

IL-5 is released in which hypersensitivity reaction:

September 2011

 A

Type I

 B

Type II

 C

Type III

 D

Type IV

Q. 9

IL-5 is released in which hypersensitivity reaction:

September 2011

 A

Type I

 B

Type II

 C

Type III

 D

Type IV

Ans. A

Explanation:

Ans. A: Type I

T-helper2 (Th2) cells release IL4, IL5, GM-CSF and other local factors that lead to an influx of eosinophils and tissue damage in contact dermatitis type of type IV hypersensitivity reaction


Q. 10

T cell interleukins are all except ‑

 A

IL 1

 B

IL 2

 C

IL 4

 D

IL 5

Q. 10

T cell interleukins are all except ‑

 A

IL 1

 B

IL 2

 C

IL 4

 D

IL 5

Ans. A

Explanation:

Ans. is ‘a’ i.e., IL 1

Cytokines: Messenger molecules of immune system

  • The induction and regulation of immune responses involve multiple interactions among lymphocytes, dendritic cells, macrophages, other inflammatory cells (e.g., neutrophils), and endothelial cells.
  • Many cellular interactions and functions of leukocytes are mediated by secreted proteins called cytokines.
  • Molecularly defined cytokines are called interleukins, because they mediate communications between leukocytes.
  • Cytokines which contribute to different types of immune responses are as follows:
  • In innate immune responses: TNF, IL-1, IL-12, type I IFNs, IFN-y,
  • In adaptive immune responses (T cell): Inducer cytokines – IL-2, IL-4, IL-5, IL-17 and IFN-y; Terminating cytokines – TGF-P and IL-10.
  • Stimulate hematopoiesis and are called colony-stimulating factors:GM-CSF, and IL-7.

Q. 11

TNF and IL1 are produced by ‑

 A

Neutrophils

 B

Monocytes

 C

Lymphocytes

 D

Activated Macrophages

Q. 11

TNF and IL1 are produced by ‑

 A

Neutrophils

 B

Monocytes

 C

Lymphocytes

 D

Activated Macrophages

Ans. D

Explanation:

Ans. is ‘d’ i.e., Activated Macrophages

Tumor Necrosis Factor (TNF) and Interleukin-1 (IL-1)

TNF and IL-I serve critical roles in leukocyte recruitment by promoting adhesion of leukocytes to endothelium and their migration through vessels.

These cytokines are produced mainly by activated macrophages and dendritic cells; TNF is also produced by T lymphocytes and mast cells, and IL-1 is produced by some epithelial cells as well.

The secretion of TNF and IL-1 can be stimulated by microbial products, immune complexes, foreign bodies, physical injury, and a variety of other inflammatory stimuli.


Q. 12

Important step in activation of naïve CD 4+ T cells and initiation of cell mediated immune response is played by Interleukin‑

 A

1

 B

2

 C

3

 D

4

Q. 12

Important step in activation of naïve CD 4+ T cells and initiation of cell mediated immune response is played by Interleukin‑

 A

1

 B

2

 C

3

 D

4

Ans. B

Explanation:

Ans. is ‘b’ i.e., 2

Activation of CD4+ T Cells:

  • Naive CD4+ T cells recognize peptides displayed by dendritic cells and secrete IL-2, which functions as an autocrine growth factor to stimulate proliferation of the antigen- responsive T cells.
  • The subsequent differentiation of antigen-stimulated T cells to TH1 or TH17 cells is driven by the cytokines produced by APCs at the time of T-cell acti- vation.
  • In some situations the APCs (dendritic cells and macrophages) produce IL-12, which induces differentiation of CD4+ T cells to the TH1 subset. IFN-y produced by these effector cells promotes further TH1 development, thus amplifying the reaction.
  • If the APCs produce inflammatory cytokines such as IL-1, IL-6, and a close relative of IL-12 called IL-23, these stimulate differentiation of T cells to the TH17 subset.

Q. 13

IL1 antagonist is ‑

 A

Anakinra

 B

Abatacept

 C

Adalimumab

 D

Leflunomide

Q. 13

IL1 antagonist is ‑

 A

Anakinra

 B

Abatacept

 C

Adalimumab

 D

Leflunomide

Ans. A

Explanation:

Ans. is ‘a’ i.e., Anakinra


Q. 14

Which of the following interleukin is secreted by T helper 2 cells‑

 A

IL 11

 B

IL 7

 C

IL 1

 D

IL 13

Q. 14

Which of the following interleukin is secreted by T helper 2 cells‑

 A

IL 11

 B

IL 7

 C

IL 1

 D

IL 13

Ans. D

Explanation:

Ans. is ‘d’ i.e., IL 13


Q. 15

Interleukin 2 is produced by

 A

T helper cells 1

 B

T helper cells 2

 C

Natural killer cells

 D

Basophils

Q. 15

Interleukin 2 is produced by

 A

T helper cells 1

 B

T helper cells 2

 C

Natural killer cells

 D

Basophils

Ans. A

Explanation:

Ans. is ‘a’ i.e., T helper cells 1


Q. 16

All are true regarding interleukin-1 except ‑

 A

Primary source is monocyte-macrophage system

 B

Endogenous pyrogens

 C

Inhibit IL-2 production by T-cells

 D

All are true

Q. 16

All are true regarding interleukin-1 except ‑

 A

Primary source is monocyte-macrophage system

 B

Endogenous pyrogens

 C

Inhibit IL-2 production by T-cells

 D

All are true

Ans. C

Explanation:

Ans. is ‘c’ i.e., Inhibit IL-2 production by T-cells

Interleukin -1

  • Also known as leucocyte activating factor (LAF) or B cell activating factor (BAF).
  • Principally secreted by macrophages and monocytes; and epithelial cells.
  • Other sources are B lymphocytes, fibroblasts and endothelial cells.
  • Immunological effects-
  • Activation of T cells for the production of IL – 2.
  • B cell proliferation and antibody synthesis
  • Neutrophil chemotaxis and increased PMN release from bone marrow.
  • Increases body temperature (important endogenous pyrogen).
  • Bone marrow cell proliferation
  • Induction of acute phase protein.


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