Activation of CD8+ murine T cells from tumor-draining lymph nodes by phorbol dibutyrate plus calcium ionophore

• Published in: Journal of immunotherapy Vol. 12; no. 1; p. 32
• Main Authors: Tuttle, T M, Inge, T H, McCrady, C M, Bethke, K P, Bear, H D
• Format: Journal Article
• Language: English
• Published: United States 01-07-1992
• Subjects: Animals; Cells, Cultured; Cytotoxicity Tests, Immunologic; Female; Immunophenotyping; Immunotherapy, Adoptive; Ionomycin - pharmacology; Lymph Nodes - immunology; Lymph Nodes - pathology; Lymphocyte Activation - drug effects; Lymphocyte Depletion; Mice; Mice, Inbred C57BL; Phorbol 12,13-Dibutyrate - pharmacology; Remission Induction - methods; Sarcoma, Experimental - chemically induced; Sarcoma, Experimental - drug therapy; Sarcoma, Experimental - immunology; Sarcoma, Experimental - pathology; T-Lymphocytes, Regulatory - drug effects; Time Factors
• ISSN: 1053-8550
• DOI: 10.1097/00002371-199207000-00004

When lymphocytes from the lymph nodes draining the site of a progressively growing MCA-105 sarcoma are stimulated in vitro with autologous tumor and low-dose interleukin-2 (IL-2), they will grow and develop the ability to lyse autologous tumor cells in vitro; these lymphocytes can also eradicate tumor metastases in vivo. Phorbol esters and calcium ionophores activate signal transduction pathways in T cells and mimic the events triggered by antigen binding. We therefore sought to determine whether large numbers of MCA-105 tumor-specific, therapeutically active T cells could be obtained from MCA-105 draining lymph nodes (DLNs) following a brief exposure to phorbol dibutyrate (PDBu) and ionomycin (Io). DLN cells primarily stimulated with autologous tumor, followed by a secondary stimulation with PDBu-Io and cultured in 20 U/ml IL-2, demonstrated marked expansion of cell numbers during 3 weeks in culture, had moderate cytolytic activity [37% at effector:target ratio (E:T) = 80:1], and were all CD8+ T cells. In contrast, DLN cells stimulated primarily with PDBu-Io and cultured in 20 U/ml IL-2 demonstrated at least 8-10-fold greater growth than antigen-stimulated DLN cells during 3 weeks, were moderately cytolytic (31% at E:T = 80:1), and were a mixed population of CD8+ and CD4+ T lymphocytes. DLN cells that were expanded by either protocol, like cells stimulated repeatedly in vitro with tumor cells, could eliminate MCA-105 pulmonary metastases when given with IL-2 in an adoptive immunotherapy model. DLN cells stimulated primarily with PDBu-Io completely eradicated MCA-105 metastases but had no in vivo antitumor activity against the syngeneic B16 melanoma or MCA-203 sarcoma.