Establishment of experimental malignant glioma-specific cytotoxic T lymphocyte clone by T cell growth factor

Abstract
✓ In an attempt to facilitate the long-term proliferative growth and subsequent cloning of cytotoxic T lymphocytes (CTL's) against syngeneic murine 203-glioma (20-methylcholanthrene-induced ependymoblastoma of C57BL/6 mouse origin), sensitized T lymphocytes from tumor-bearing mice were cultured in the presence of T cell growth factor (TCGF). Of five clones established by a limiting dilution technique, two clones (G-CTLL 1 and 2) exhibited tumor-specific cytotoxicity. G-CTLL 1 cells, which possessed much higher cytotoxic activity than G-CTLL 2 cells, were further analyzed. G-CTLL 1 cells were maintained in a TCGF-dependent exponential proliferative culture for over 18 months and continued to mediate an extremely high cytotoxic activity with the target specificity (50- to 100-fold increases over the peak cytotoxic activity of sensitized T lymphocytes in tumor-bearing mice). Their phenotypes of surface antigens were Thy-1+ (weak positive), Lyt-1.−2.+3+, and asialo-GM1−, and their cytotoxicity was blocked by ...