Researchers are now investigating interferon-beta and interferon-gamma, both of which have some similar antitumor effects. And all the interferons are being evaluated in combination with other cytokines or in combination with chemotherapy . What isn't understood very well yet is the exact mechanism that makes the interferons effective. They may make the tumor cells seem more foreign (increase the antigenicity), which makes them more vulnerable to attack by antibodies or by the various immune cells.
Interleukins There are many interleukins (IL-1 through IL-12). The one most intensively investigated by the National Institutes of Health of the United States and many universities is interleukin-2, which increases the activity of lymphocytes . The lymphocytes that have been non-specifically activated by IL-2 are called LAK cells (lymphokine-activated killer cells), and these do a much better job of identifying and destroying tumor cells than ordinary lymphocytes. All the other interleukins are still in an early investigational stage, but several will soon be studied in cancer patients.
Some researchers have tried to make IL-2 treatment more effective by collecting lymphocytes from a patient's blood with a special machine, activating them with IL-2 in the laboratory, then returning them to the patient as LAK cells along with more IL-2. An alternative is to activate lymphocytes from a patient's tumor, producing what are called tumor infiltrating lymphocytes (TIL cells).
