Crabshoot; September 1994; Scientific American Magazine; by Beardsley; 1 Page(s)

The idea of using a vaccine for stimulating the immune system to fight tumors has a long, undistinguished history. Because early attempts were based on extracts of tumors, which are inherently variable, occasional reports of success generally led nowhere.

In the past few years the climate has radically changed. Advanced cell culture techniques have made possible the identi fication of specific antigens--substances recognized by the immune system-- that are present on tumor cells in larger amounts than they are on ordinary cells. Using monoclonal antibodies, workers have been able to distinguish different types of cells in the immune system from one another so that the body's responses can be minutely monitored. More recently, tools such as the polymerase chain reaction (PCR) have been used to analyze and copy tiny samples of gene fragments. Rapid progress in identifying cytokines, the chemicals that control the immune system, raises the hope that essential support from T cells can be mobilized.