BIOTECHNOLOGY - V. H. Gerasymenko - 2006

Part II. Special Biotechnologies

Chapter 13. BIOTECHNOLOGY OF INTERFERON PRODUCTION

13.2. TRADITIONAL METHODS FOR INTERFERON PRODUCTION

The process of interferon production is basically similar for all types of Cells grown in culture that produce interferon. Most commonly, cells are infected with Sendai virus or Newcastle disease virus and centrifuged after 24 hours. A crude interferon preparation is obtained from the supernatant and subsequently subjected to purification.

Production of α-interferon. Under the auspices of the International Committee of the Red Cross, the production and testing of α-interferon preparations obtained from donor Blood Leukocytes was established in Finland. Sendai virus or Newcastle disease virus was used as an inducer. However, the efficiency of interferon production by simple isolation is very low. From 250 L of blood (which can be obtained from 500–1000 Donors), 0.25–0.5 mg of pure α-interferon is obtained, which is sufficient to treat 50 patients with a mild form of the disease and only one patient with a severe form.

The technology for producing interferons from blood leukocytes became widespread, but it could not fully meet the demand for this preparation due to several drawbacks: first, the limited availability of raw Materials (donor blood); second, normal, i.e., non-cancerous, leukocytes cannot be successfully cultured, making large-scale interferon production overly complex; third, the purity of the final product is unsatisfactory because a mixture of α-interferons is obtained; and fourth, the high production cost of the resulting product.

French and Israeli scientists developed a facility for isolating interferon from leukocytes of patients with chronic myeloid leukemia treated with Sendai virus. As a result, the interferon yield was significantly higher than when using normal leukocytes. However, because the method is based on the cultivation of Cancer cells, The Scope of application of the resulting interferon is limited.

Fibroblast interferon (β-interferon) is synthesized by fibroblasts (Connective Tissue cells) obtained from fetal Tissues or from foreskin material of newborn infants after circumcision, following their Treatment with Sendai virus.

Fibroblasts can be cultured, making them suitable for large-scale interferon production. This is simpler than obtaining it from leukocytes. However, the method has drawbacks: in culture vessels, fibroblasts form a monolayer one Cell thick, which limits the interferon yield. This yield can be increased by introducing microscopic microbeads into the culture medium, to which the cells attach.

The yield of β-interferon from fibroblast cultures is higher, but it remains costly. Given that only elevated doses of interferon are effective in cancer treatment, according to American researchers, treating a single cancer patient with interferon costs $20,000–$40,000.

Immune, or γ-interferon, is synthesized by T-lymphocytes. Its production is induced by numerous substances. At the University of Texas, by stimulating lymphocytes with staphylococcal protein A (enterotoxin), a yield of 1,000 units of γ-interferon per 1 million cells was achieved. The British firm Wellcome obtained interferon from lymphoblastoid cells harvested from newborn hamsters. In the USA, interferon was produced from a culture of donor blood lymphocytes stimulated with a mitotic agent.

Overall, none of the Methods for obtaining interferons of all three classes could satisfy demand due to low product yields, high costs (industrial production costs reach $40–$50 per 1 million units), and insufficient purity of the preparations.

Consequently, research began in all countries aimed at applying Introduction/32.html">Genetic Engineering METHODS to produce relatively inexpensive interferon in quantities sufficient to meet the demand from public health, veterinary medicine, and livestock sectors.