title: Ex vivo expansion of tumor-draining lymph node cells using compounds which activate intracellular signal transduction. II. Cytokine production and in vivo efficacy of glioma-sensitized lymphocytes.
abstract: We have investigated the anti-tumor activity of ex vivo activated and expanded T cells which had been sensitized in vivo to one of two different syngeneic rat glioma cell lines; D74 or RT-2. Rats were sensitized by inoculation of irradiated tumor cells into each hind foot pad. After 10 days, the tumor-draining lymph node (DLN) from each popliteal region was excised and prepared as a single cell suspension. Tumor-DLN lymphocytes were next activated overnight in RPMI-1640 medium containing 10% fetal bovine serum (FBS), Bryostatin-1 (5 nM), ionomycin (1 microM), and 20 U human recombinant interleukin-2 (IL-2) per ml. Culture for seven days in RPMI-1640 supplemented with FBS and IL-2 resulted in approximately 100-fold expansion of the lymphocyte population. Both D74- and RT-2-sensitized T cells constitutively secreted tumor necrosis factor-alpha, and both lymphocyte populations produced comparable amounts of the cytokine when co-cultured with either glioma cell line. Neither D74- and RT-2-sensitized effectors constitutively secreted gamma-interferon (gamma-IFN), but both populations produced gamma-IFN when exposed to either glioma cell line in vitro. D74-sensitized T cells released significantly more gamma-IFN than the RT-2 DLN lymphocytes. In vitro Chromium-release assays indicated that RT-2-sensitized T cells were more cytotoxic for RT-2 targets than for the D74 line and that D74-sensitized effectors were also more cytotoxic for RT-2 targets. To assess in vivo therapeutic efficacy, rats who had been inoculated intradermally with RT-2 cells three days earlier received an intravenous injection of RT-2- or D74-sensitized DLN cells (10(6) cells/gram body weight) expanded after activation with Bryostatin-1 and ionomycin or an equal number of lymphokine-activated killer (LAK) cells. Tumor diameters were measured daily and revealed that injection of glioma-sensitized lymphocytes led to the elimination of tumor while treatment with LAK cells had no therapeutic benefit. These results indicate, that at least for these two glioma lines, gamma-IFN release, rather than in vitro cytotoxicity, was a better predictor for in vivo immunotherapeutic efficacy of the glioma-sensitized, expanded T cells.
authors.affiliation: Virginia Commonwealth University, Medical College of Virginia, Department of Anatomy, Richmond, USA.
authors.forename: C D
authors.initials: CD
authors.lastname: Rice
authors.forename: N G
authors.initials: NG
authors.lastname: Baldwin
authors.forename: R T
authors.initials: RT
authors.lastname: Biron
authors.forename: H D
authors.initials: HD
authors.lastname: Bear
authors.forename: R E
authors.initials: RE
authors.lastname: Merchant
mesh_terms: D000818:Animals; D001932:Brain Neoplasms / Q000276:immunology* / Q000648:ultrastructure; D002450:Cell Communication / Q000187:drug effects*; D002860:Chromium Radioisotopes; D016207:Cytokines / Q000096:biosynthesis*; D005260:Female; D005910:Glioma / Q000276:immunology* / Q000648:ultrastructure; D016219:Immunotherapy, Adoptive; D007371:Interferon-gamma / Q000096:biosynthesis; D008198:Lymph Nodes / Q000166:cytology / Q000187:drug effects / Q000648:ultrastructure*; D051381:Rats; D011916:Rats, Inbred F344; D015398:Signal Transduction / Q000187:drug effects*; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D002860:Chromium Radioisotopes; D016207:Cytokines; D007371:Interferon-gamma