Presence of gd TcR+ Tumor Infiltrating Lymphocytes (TILs) in One Case of Pediatric Osteogenic Sarcoma

To characterize ab and gd TcR expression in cultured TILs from a metastatic osteogenic sar- coma.Patient and methods: TILs were isolated from a lung metastasis of an osteogenic sarcoma in a 16- year-old female patient. Culture conditions were IL- 2 and anti-CD3 MoAb+IL-2. TcR expression and surface phenotype were studied by flow cytometry. 4h-chromium release assays were used to assess cytotoxicity.
Results:IL-2-expanded tumor infiltrating T-lym- phocytes contained 50% gd TcR+ cells whereas gd TcR+ cells represented 20% of T-cells in cultures expanded with anti-CD3 MoAb+IL-2. The phenotype of gd TcR+ cells was CD3+, CD16-, CD4-, CD8-, and CD29+. AnH-CD3 MoAb + IL-2-expanded TILs mediated a significant lysis of thé autologous tumor and of an allogeneic lymphoma and displayed a higher activity against thé NK-sensitive target K562. In cold target experiments, unlabeled autol- ogous tumor cells blocked thé lysis of K562, indicating that MHC-unrestricted effectors were involved in thé lysis of both targets.
Conclusions: This report demonstrates thé ex- pansion of large numbers of gd TcR+ T-cells after short-term culture of TILs from a metastatic os- teosarcoma. Further studies are needed to déter- mine thé role of gd TcR+ cells in host immune responses directed against this tumor.