Activation of CD8+ murine T cells from tumor-draining lymph nodes by phorbol dibutyrate plus calcium ionophore.
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.(ABSTRACT TRUNCATED AT 250 WORDS)
Tuttle
T M
TM
Department of Surgery, Massey Cancer Center, Medical College of Virginia, Richmond 23298.
Inge
T H
TH
McCrady
C M
CM
Bethke
K P
KP
Bear
H D
HD
D000818:Animals; D002478:Cells, Cultured; D003601:Cytotoxicity Tests, Immunologic; D005260:Female; D016130:Immunophenotyping; D016219:Immunotherapy, Adoptive; D015759:Ionomycin / Q000494:pharmacology*; D008198:Lymph Nodes / Q000276:immunology* / Q000473:pathology; D008213:Lymphocyte Activation / Q000187:drug effects*; D008212:Lymphocyte Depletion; D051379:Mice; D008810:Mice, Inbred C57BL; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology*; D012074:Remission Induction / Q000379:methods; D012513:Sarcoma, Experimental / Q000139:chemically induced / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects*; D013997:Time Factors
D015240:Phorbol 12,13-Dibutyrate; D015759:Ionomycin