SCIENTISTS are testing a new generation of cancer vaccines that use a person’s dendritic cells, a type of white blood cell, to stimulate the body’s immune system. Normally, the immune system has trouble recognising tumours because cancer cells arise from the same tissues as normal cells. But these vaccines “train” the immune cells to distinguish malignant cells from normal ones, and to attack only the cancer cells.
1. Doctors extract a number of dendritic cells, which normally patrol for disease-producing agents.
2. Bits of the patient’s tumours, containing antibody-producing antigens, are exposed in the laboratory to dendritic cells, which pick up the antigens.
3. The antigen-bearing dendritic cells are injected back into the patient. They then display the antigen to the killer T-cells, which become activated to hunt down cells in the body that carry that particular antigen.
4. Unlike chemotherapy or radiation, these vaccines do not destroy healthy cells or have debilitating side effects.