An interferon is a protein produced by the body's immune system in response to an infection. Interferons are part of a larger group of proteins known as cytokines, and they are made by cells such as leukocytes, T-cells, and fibroblasts. In addition to being made naturally in the body, interferon can also be produced in laboratories for the purpose of medical treatment, and several pharmaceutical companies have versions of interferon on the market.
There are three types of interferon: Type I, Type II, and Type III. These types are divided by the types of cells they interact with, how they are produced, and what they do. Type I interferons include subclassifications known as alpha, beta, kappa, delta, epsilon, tau, omega, and zeta. The Type II interferons include interferon-gamma, made by the T-cells, while the Type III category consists of several versions of interferon-lambda. The Type III classification is not accepted by all members of the medical community.
When the body detects the signs of a viral intrusion or infection, it can trigger the production of interferons. The interferons can stimulate the production of specific proteins, inhibiting viral replication inside the cells of the body and making the body more resistant to the virus. The body only makes these proteins when they are needed, because they can interfere with normal activities such as the production of red blood cells. Other animals also produce cytokines in response to infections and viral incursions, although these proteins vary from animal to animal.
In medical therapy, interferons are sometimes administered to boost the function of the immune systems. Interferon injections are used in the treatment of some cancers so that the body can fight the atypical cells characteristic of the cancer more effectively, and these proteins are also used in the treatment of conditions such as hepatitis C. Interferon treatment can be grueling for patients, and they generally experience symptoms such as nausea, irritability, and fatigue.
Additional types of interferon are constantly being discovered, and researchers are always learning new things about the functions of these proteins in the body. Additional research has revealed a range of potential therapeutic uses, and it has also helped the medical community understand how the immune system works, and what can cause it to break down. In addition to being approved for a range of medical treatments, these proteins are sometimes administered in off-label situations to treat conditions which appear to respond to interferon.