The designer cytokine hyper-IL-6 mediates growth inhibition and GM-CSF-dependent rejection of B16 melanoma cells.
The low immunogenic B16 melanoma cell line was transfected with a mammalian expression vector containing the complementary DNA for a sIL-6R/IL-6 fusion protein, termed Hyper-IL-6 (H-IL-6), which was shown to have biological activities at 100-1000-fold lower concentrations than IL-6 in combination with sIL-6R. The secreted p84 glycoprotein was detected in the supernatant of transfected cells and was fully active on BAF3/gp130 cells, which respond to IL-6/sIL-6R but not to IL-6 alone. Administration of recombinant H-IL-6 to C57BL/6 mice resulted in a prolonged acute phase protein gene expression indicating long systemic persistence of the fusion protein. Transfected B16 cells (B16/H-IL6 cells) showed morphological alterations in combination with a dramatic growth inhibition in vitro. Subcutaneous injection in C57BL/6 mice resulted in an almost complete rejection of B16/H-IL6 cells. This effect was partially abolished in FVB/BL/6 mice transgenic for a GM-CSF receptor antagonist, indicating a GM-CSF-dependent rejection of H-IL-6 transfected B16 cells. These results demonstrate that the anti-tumor effect of cytokines like IL-6 which are secreted by transfected melanoma cells at least in part depends on GM-CSF activity.
Ozbek
S
S
Department of Medicine, Section of Pathophysiology, University of Mainz, Obere Zahlbacher Strasse 63, D-55101 Mainz, Germany.
Peters
M
M
Breuhahn
K
K
Mann
A
A
Blessing
M
M
Fischer
M
M
Schirmacher
P
P
Mackiewicz
A
A
Rose-John
S
S
D000818:Animals; D004347:Drug Interactions; D006084:Graft Rejection; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000494:pharmacology*; D006131:Growth Inhibitors / Q000494:pharmacology*; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D015850:Interleukin-6 / Q000235:genetics / Q000494:pharmacology*; D008546:Melanoma, Experimental / Q000276:immunology*; D051379:Mice; D008822:Mice, Transgenic; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / Q000037:antagonists & inhibitors; D018123:Receptors, Interleukin / Q000235:genetics; D019947:Receptors, Interleukin-6; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000494:pharmacology*; D014162:Transfection
D006131:Growth Inhibitors; D007166:Immunosuppressive Agents; D015850:Interleukin-6; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor; D018123:Receptors, Interleukin; D019947:Receptors, Interleukin-6; D011993:Recombinant Fusion Proteins; C104543:interleukin 6-interleukin 6 receptor fusion protein, recombinant; D016178:Granulocyte-Macrophage Colony-Stimulating Factor