High Levels of Antibodies May Be Linked to Low Levels of Cancer

Active immunization can trigger the body to produce highly efficient IgE antibodies that attack tumors. This achievement, performed in an animal model, is based on the skillful combination of two established experimental techniques.

The study's results will be published in May 1, 2007, issue of the journal Cancer Research, and are part of a project funded by the Austrian Science Fund (FWF; Vienna, Austria). The antibodies produced during the study belong to a class that also plays a critical role in the development of allergic reactions.

Individuals who suffer from allergies are very familiar with immunoglobulin E (IgE). It is this class of antibodies that plays a major role in causing an allergy sufferer's immune system to overreact. In addition, oncologists are well acquainted with IgE. Many in-depth studies have demonstrated that those individuals with increased levels of IgE are much less likely to suffer from certain types of cancer. Or in other words, allergy sufferers are at a lower risk of developing cancer.

"In actual fact, the IgE produced during an allergic reaction does not attack cancer tumors but instead attacks allergens, for example pollen,” explained the study's leader, Prof. Erika Jensen-Jarolim, head of the department of pathophysiology at the Medical University of Vienna (Austria). "The fact that IgE nevertheless acts against tumors is more of a fortunate side-effect of the highly efficient characteristic of this antibody class. It was our aim to make this antibody class, which is typical for allergies, act directly against tumors. At the same time, we wanted to encourage the long-term production of IgE in the body by means of active immunization.”

Prof. Jensen-Jarolim's group recently succeeded in achieving active immunization against specific types of tumors in mice. However, due to the selected type of immunization (injection below the abdominal wall), the antibodies that were produced belonged to the IgG class. This type of antibody generates a much more limited and shorter-term effect against tumors than IgE antibodies.

Prof. Jensen-Jarolim used one of her group's previous successes--achieved as part of another FWF project on food allergies--to ensure that immunization resulted in the intended activation of IgE. These results validate that food proteins are effective in inducing IgE-dependent immune reactions when they withstand the acidic environment of the stomach.

Prof. Jensen-Jarolim's team, therefore, fed mice a peptide very similar to a tumor peptide while decreasing acidification in the stomach, thus deterring digestion of the peptide. As a consequence, a type of allergic reaction was triggered against this tumor-like peptide--the mice produced tumor-specific IgE antibodies. The result is the world's first active IgE-stimulating tumor vaccination.


Related Links:
Austrian Science Fund
Medical University of Vienna