BT302 Final Term MCQs and Subjective by Tabih Fatima

35: Interleukins:

They are mediators between leucocytes

36: Chemokine:

They are responsible for leucocytes migration 37: Cytokines function as cascade signaling in the form of cytokine network.

38: mRNA

For cytokines are short lived.

39: What is Redundancy?

It is due to the nature of cytokine receptors. 40: Different cells can respond to same cytokine due to: Structural similarities 41: Cytokine response in how many ways: Three ways

42: what is Autocrine :

Effect on same cell which secrete cytokine

43: Paracrine:

Effect on nearby cells to cells which secrete cytokine

44: Endocrine:

Effect on distant cells through circulation 45: Cytokines categorized on which basis:

Two basis

46: On basis of source cell what are Monokines?

It produced by mononuclear phagocytic cells e.g. Interferon gamma & Interleukin (IL1) from macrophages & Monocytes.

47: On basis of source cell what Lymphokines?

Produced by activated lymphocytes e.g. IL-3, IL-4 & IL-5

48: On basis of source cell what Interleukins?

They are mediators between leucocytes e.g. IL-1, IL10& IL-18

49: On basis of source cell what Chemokine’s?

They are responsible for leucocytes migration e.g. IL-8 50: Types of cytokine on basis of function: 1: Cytokines which act for innate (non-Specific) immune system e.g. TNFα, IL-1, Il 10 etc. 2: Cytokines which act for Adaptive (Specific) immune system e.g. Il2,IL-4 & IL-5

51: What are Tumor Necrosis Factor-Alpha (TNF-α) :

It is produced by activated macrophages in response to microbes or their products for example lipopolysaccharides (LPS) of gram negative bacteria. It acts a mediator of acute inflammation. It recruits neutrophils and macrophages at the site of infection either by stimulating endothelial cells to secrete adhesion proteins or by secreting chemokines. Moreover, TNF-a induces fever and acute phase proteins in host.

52) IL-1

This is also an inflammatory cytokine as like TNF-a. It is produced by activated macrophages. Furthermore, it also help to activate T-cells.

53) IL-10

It is an inhibitory cytokine which inhibits the cytokine production of cytokines from macrophages.

54) IL-12

This cytokine is produced by dendritic cells and macrophages. It enhances the cytolytic activity of cytotoxic T-cells

55) Type I interferon

This class of interferon include Interferon α & β. These inhibit viral replication in cells by increasing the expression of class I MHC which in turn make them susceptible to cytotoxic T-lymphocytes (CTL).

56) IFN-γ

It is produced primarily by Th1 cells. It enhances the cytolytic activity of NK cells by induction of class I & II MHC molecules.

57) Chemokines

These are chemotactic cytokines produced by many leucocytes. These recruits inflammatory cells at site of infection for an inflammatory response.

Q58. Which cytokines which act primarily for Adaptive (Specific) immune system?

1) IL-2

It is produced by T-helper (Th) cells but Cytotoxic T-cells (Tc) also produced it in lesser extent. It stimulate B-cell division. It can also activate NK cells and monocytes. Moreover, IL-2 acts on T-cells in autocrine manner.

2. IL-4

IL-4 is produced by macrophages and Th2 cells. It promotes the development of Th2 from naïve T-helper (Th) cells. The Differentiated Th2 cells result in the production of antibodies. IL-4 also involves in the class switching of antibody into IgE

3. IL-5

IL-5 is produced by Th2 cells. It promotes the development of B-cells and eosinophils. It also activates mature eosinophils.

4. Tumor Growth Factor (TGF)-β

TGFβ is produced by T cells and many other cells types. It acts as inhibitory cytokine which inhibits the proliferation of T-cells and activation of macrophages. It also acts on neutrophils and endothelial cells to block the effects of proinflammatory cytokines.

Q59. What are three phases of Immuno-regulation ?

1. Recognition phase
2. Activation Phase
3. Effector Phase