Treatment of Murine Gliomas by Adoptive Transfer ofex VivoActivated Tumor-Draining Lymph Node Cells

The adoptive transfer of tumor-reactive T lymphocytes has recently been demonstrated to be an effective means for mediating the regression of experimental intracranial fibrosarcomas. In this study, mice bearing syngeneic intracranial GL261 gliomas were cured by the combination of sublethal whole body irradiation followed by the intravenous transfer of tumor-draining lymph node (LN) T cells activated with anti-CD3 or staphylococcal enterotoxin C2 (SEC2). To further identify the functional effector T cell population in the adoptive immunotherapy, LN T cells were separated into two subsets, based on the level of expression of the cell adhesion molecule CD62L (L-selectin). As few as 5 × 105CD62Llowcells could cure the majority of animals, whereas 2 × 106CD62Lhighcells were completely ineffective. Moreover, T cells isolated from advanced intracranial tumors were identified to be predominantly CD62Llow. In contrast, spleens contained a mixture of CD62L low and high cells similar to the transferred cell population. T cells in the glioma site were more actively proliferating than those isolated from the spleen. Mice cured of GL261 tumors demonstrated long-term immunologic memory by rejecting intracranial challenges of the original tumor but not an immunologically distinct tumor. Furthermore, despite infiltration of transferred cells into the intracranial tumors, cured mice did not exhibit any apparent neurologic abnormalities during treatment, prolonged follow-up, or after intracranial tumor rechallenge. This study demonstrates the effective treatment of an intracranial murine glioma by the systemic adoptive transfer of activated tumor-draining LN T cells and selective tumor infiltration by the therapeutically active CD62LlowT cells.