RT Journal Article SR Electronic T1 Intratumoral Vaccination with Vaccinia-Expressed Tumor Antigen and Granulocyte Macrophage Colony-Stimulating Factor Overcomes Immunological Ignorance to Tumor Antigen JF Cancer Research JO Cancer Res FD American Association for Cancer Research SP 6956 OP 6961 VO 63 IS 20 A1 Yang, Arvin S. A1 Monken, Claude E. A1 Lattime, Edmund C. YR 2003 UL http://cancerres.aacrjournals.org/content/63/20/6956.abstract AB Using a murine transitional cell carcinoma tumor model, MB49, which naturally expresses the male antigen HY, we evaluated whether tumor ignorance as determined by lack of a systemic immune response could be overcome by immunization with vaccinia expressed tumor antigen and granulocyte macrophage colony-stimulating factor. Systemic tumor ignorance of MB49 was demonstrated by the lack of a splenic HY-specific CTL response in MB49-bearing female mice. In contrast, we demonstrated HY-specific CTL priming in the draining lymph nodes. MB49-bearing female B6 mice were immunized with VVHY+VVGMCSF intratumorally or in the contralateral flank. Intratumoral VVHY, VVGMCSF, and keyhole limpet hemocyanin (to produce CD4 help) generated splenic HY-specific CD8 CTLs, whereas immunization with the combination in the contralateral flank or single agents given intratumorally failed to yield a splenic response. Purified male T cells injected intratumorally, as a source of HY antigen, also generated a HY-specific response, whereas contralateral immunizations did not. These finding expand the understanding of tumor immunological ignorance and support intratumoral vaccination as a strategy for immunotherapy of established tumors. ©2003 American Association for Cancer Research.