Genetic techniques to overcome antitumor anergy

Immunotherapy of malignant tumors is often hampered by "immune escape" phenomenons of tumor cells. Both active (e.g. induction of T-cell apoptosis, secretion of immunomodulators, -downregulators) and passive (e.g. antigen shedding, loss of MHC-class I/II molecules on the tumor cell surface) mechanisms are involved in this process. Another reason are inborn or acquired immunodeficiency syndromes. Gene technology tries to reconstitute the immunocompetent status by genetic compensation or modulation of the defect. Some of these trials have been performed already in phase I studies of different kinds of tumors and will be shortly presented here.