Active cellular immunotherapy of cancer, via gene-modified tumor cells
, may develop to an effective treatment modality. Here we discuss some
of the cytokines used in gene transfer, the importance of MHC class I
expression on tumor cells used as vaccines, the relevance of experime
ntal tumor systems to human tumors, and the use of live versus irradia
ted vaccines. Possible methods for effective gene transfer and possibl
e protocols for immunotherapy studies are presented. Our studies in tw
o highly metastatic murine tumors, the Lewis lung carcinoma (3LL) and
the B16 melanoma, and immune mechanisms involved in immunotherapy of m
etastasis are summarized.