Monitoring the trafficking of adoptively transferred antigen-specific CD8-positive T cells in vivo, using noninvasive luminescence imaging

Understanding of the trafficking of antigen-specific CD8⁺ T cells in vivo will provide insight about how our immune system controls infectious diseases and cancers. In the current study we used a luciferase-expressing human papillomavirus type 16 (HPV-16) E7-specific CD8 ⁺ T cell for adoptive transfer to control E7-expressing TC-1 tumor cells. We used noninvasive luminescence imaging to monitor the trafficking of E7-specific CD8⁺ T cells over time. We also boosted the luciferase-expressing E7-specific CD8⁺ T cells in vivo, using E7-expressing vaccinia. We found that injected E7-specific T cells preferentially migrated to the E7-expressing tumor site but not to the E7-negative control tumor site, and increased in number at the tumor site over time. In addition, vaccination with E7-expressing vaccinia led to a significant increase in the number of E7-specific CD8+ T cells at the tumor site, resulting in a significant antitumor effect compared with vaccination with wild-type vaccinia. Thus, our data suggest that the antitumor effects generated by adoptive transfer of E7-specific CD8+ T cells can be significantly enhanced by vaccination with E7-expressing vaccinia and that our system represents a plausible approach to investigate the trafficking and biology of antigen-specific T cells in vivo.