Radiation Oncology/RT Techniques/Interferon alpha (IFNα)

• Interferons (IFNs) are a group of signaling proteins made and released by host cells in response to the presence of several viruses
• In a typical scenario, a virus-infected cell will release interferons causing nearby cells to heighten their anti-viral defenses
• The mammalian types are designated IFN-α (alpha), IFN-β (beta), IFN-κ (kappa), IFN-δ (delta), IFN-ε (epsilon), IFN-τ (tau), IFN-ω (omega), and IFN-ζ (zeta, also known as limitin)
• The IFN-α proteins are produced mainly by plasmacytoid dendritic cells (pDCs)
  • They are mainly involved in innate immunity against viral infection
  • The genes responsible for their synthesis come in 13 subtypes that are called IFNA1, IFNA2, IFNA4, IFNA5, IFNA6, IFNA7, IFNA8, IFNA10, IFNA13, IFNA14, IFNA16, IFNA17, IFNA21
  • These genes are found together in a cluster on chromosome 9
• IFN-α is also made synthetically as medication in hairy cell leukemia
  • The pegylated types are pegylated interferon alfa-2a and pegylated interferon alfa-2b
• Alpha interferons are used in the treatment of chronic viral hepatitis (C and B), some solid tumors (e.g., Kaposi sarcomas in patients with HIV infection), melanoma, and certain leukemias