Interferons final ppt.pptx

Interferons

1. INTERFERONS

2. Definition These are naturally occurring proteins inside the body which interferes with the ability of viruses to reproduce. They belong to cytokine barriers of innate immunity.

3. IMPORTANT FEATURES First recognised by their ability to interfere with viral infections in culture cells Does not protect the virus infected cell that produces it Itself is not an antiviral agent It moves to other cells where it produces an antiviral state(By inhibiting Viral replication)

4. Types ∆ IFN Alpha * Produced by macrophages *Antiviral action ∆ IFN Beta Produced by fibroblasts Antiviral action ∆ IFN Gamma Produced by T helper cells Major role in activation of anti cancer immunity

5. Mechanism of action No direct action Non specific in action Induce host cells to produce certain proteins which in turn inhibit host cell protein synthesis INTERFERONS are produced quickly following infection Donot have immunological memory

6. INDUCTION OF INTERFERON A. IFN-alpha & beta (Type-I- IFNS) When prototypic cell of origin is exposed to - Viruses -Double stranded RNA - Cytokines B. IFN-Y (Type-II- IFNS) Following a number of immunological stimuli including : -T-cell specific antigen -Staphylococcal enterotoxin -A -Mitogens (Phyto haemagglutinin,PhorbolEster etc)

7. INDUCERS The following agents can induce IFN synthesis * Togaviruses * Vesicular stomatitis virus * Sendai virus * New castle disease virus * ds RNA * Bacterial endotoxins

8. Applications IFN Alpha is used in following Clinical Conditions: . * Topically: . Rhinoviral infections,genital warts,herpetic keratitis . * Systemically : Chronic hepatitis B,C& D infection *Antiproliferative action can be utilised to treat hairy cell leukemia,Kaposi’s sarcoma And autoimmune diseases such as multiple sclerosis

9. Preparation of interferons Available in 2 forms: * Human IFNs ✓ Prepared commercially byr ecombinant DNA technology * Pegylated IFNs ✓ IFN Alpha linked to polyethylene glycol ✓ Slower absorption,decreased clearance,more sustained serum Concentration ✓ Can be administered once ina week

10. Genital warts Herpetic keratitis Kaposi’s Sarcoma