by RIZWAN ULLAH CVAS JHANG

1. Presented By:
Group 3rd(VA 123-132)
Presented to:
Sir Usman Waheed

3. Origin of the name
 Interferons are named after their ability to
"interfere" with viral replication within host cells.
DEFINITION:
Natural Interferons are glycoproteins and proteins
made and released by host cells to counteract both
micro-organisms; viruses, bacteria, parasites and
tumor cells.

4. INTERFERONS BASICS
 Interferons play an important role in the first line
of defense against viral infections
 Interferons are part of the non-specific immune
system
 Interferons are made by cells in response to an
appropriate stimulus

5. Types of interferon
According to pharmacological
structure
1. Alpha (leukocyte interferon)
 By virus infected leukocytes
2. Beta (fibroblast interferon)
 By virus infected fibroblasts or
epithelial cells
3. Gamma (immune interferon)
 By activated T cells & NK cells

7. MODE OF ACTION
OF INTERFERON

8. virus
cells
(Other stimuli:
exogenous ds RNA,
LPS, bacterial
components)

9. virus
interferon

10. virus
Inhibitor
y
proteins
No replication

12. Viral Defence Against Interferon
 inhibit action of interferon-induced protein
kinase
 inhibit Natural Killer function
 complement activation
 prevent apoptosis in host cell

13. DIFFERENCE BETWEEN
INTERFERONS AND ANTIBODIES
ANTIBODY:
Antibody are globular proteins produced by plasma cells
of B cells that reacts specifically with antigen that
stimulated their production.

14. INTERFERON
Interferons are antiviral glycoproteins released by living
cells in response to viral attack and induce a viral
resistant state to neighboring cells.

15. Antibodies Interferons
1) Antibodies produced are circulated in
blood and lymph to dispose off
antigens.
Interferons released by infected cells
enter the neighboring healthy cells to
enhance their antiviral defence.
2) They are slow in action but give a
long lasting protection because of
immunologic memory.
They are quick in action but give only
temporary protection.
3) They act outside the cell and can
directly bind to epitopes of antigen.
They act inside the cell and induce
synthesis of many defense proteins to
establish an antiviral state.
4) They form body’s 3rd line defence
which involves specific immune
response.
They form body’s 2nd line of defence
which involve non-specific response.
Major Differences

17. ANY QUESTION
????????

18. THANK YOU!