Whether tumors of different lineages share common Ags is a critical issue for understanding anti-tumor immune responses and for designing Ag-specific tumor immunotherapy. Because of lack of cross-protection among individually derived tumors, it has been proposed that tumor Ags are specific for individual tumors. Here we show that lack of cross-protection is not due to lack of a shared tumor Ag. Thus, a plasmocytoma J558 transfected with the costimulatory molecule B7 activates a cross-reactive CTL response in vivo. The major Ag recognized by the cross-reactive CTL is P1A, which is expressed in mastocytoma P815, plasmocytoma J558, and fibrosarcoma Meth A. Surprisingly, no significant cross-protection can be detected among P1A- expressing tumors after immunization with either P1A-expressing or B7- transfected P815 cells. Our results demonstrate that multiple lineages of tumors are not cross-protected even though they share a tumor Ag that can be recognized by CTL. These results have important implications for tumor immunotherapy.
|Original language||English (US)|
|Number of pages||7|
|Journal||Journal of Immunology|
|Publication status||Published - 1995|
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