BIOTECHNOLOGY - V. H. Herasymenko - 2006

Part II. Special Biotechnologies

Chapter 13. BIOTECHNOLOGY OF INTERFERON PRODUCTION

13.1. CLASSES AND TYPES OF INTERFERONS

There are three distinct classes of interferons: leukocyte (α-interferon), fibroblast (β-interferon), and immune (γ-interferon).

1) α-Interferon is synthesized by leukocytes in response to viral infection. It has approximately 20 recombinant variants (A, B, C, D, E, F, etc.) that differ in their Amino Acid Composition and sequence within the polypeptide chain, as well as in their biological activity.

2) β-Interferon is produced by Connective Tissue fibroblasts under viral induction.

3) γ-Interferon is biosynthesized in sensitized T-lymphocytes in response to mitogens, bacterial and viral Antigens, and antisera directed against lymphocyte surface determinants. No recombinant variants have been identified for either β- or γ-interferons.

The interferon classes differ in their molecular Structure, certain biological properties, and the types of Cells that produce them within the body. Specifically, the β-interferon Class consists of several Proteins, with the number of genes encoding them approaching 20; γ-interferon is represented by a single protein encoded by a single Gene. To date, a single gene corresponding to human β-interferon has been isolated, namely interferon β₁. This protein accounts for virtually all the antiviral activity observed following fibroblast induction. β- and γ-interferons are conjugated with glucose residues (glycosylated), whereas α-interferon lacks monosaccharide residues.

In addition to these three classes, interferons are categorized into two types. α- and β-Interferons belong to type I and are classified as virus-induced. Immune, or γ-interferon, belongs to type II, The Biosynthesis of which is induced by other agents (such as staphylococcal protein A-enterotoxin, various antigens, etc.).