Monocyte-Conditioned Medium Factor as Auto-activation Signal for Monocyte Tumor Cytotoxicity
The usefulness of tumoricidal macrophages as cancer treatment modality has been studied previously. Recently, cancer researchers have gained much interest in the use of biological response modifiers; therefore we, like others [1, 2], wanted to study the feasibility of using tumoricidal macrophages as an additional modality for the treatment of cancer. We studied the effects of two immunomodulators, lipopolysaccharide (LPS) and human recombinant interferon-γ (IFN-γ) on the development of tumor cytotoxicity in freshly isolated and cultured human monocytes. In our system, freshly isolated monocytes showed very low levels of tumor cytotoxicity when the effector cells were cultured in a medium supplemented with autologous serum. Enhanced tumor cytotoxicity was only observed when LPS was added to the culture medium; IFN-γ did not enhance tumor cytotoxicity at all. The addition of both LPS and IFN-γ did result in cytotoxicity levels equivalent to those obtained with LPS alone, indicating neither additive nor synergistic effects of the two immunomodulators.
KeywordsAutologous Serum Biological Response Modifier Tumoricidal Activity Centrifugal Elutriation Separation Chamber
Unable to display preview. Download preview PDF.
- 1.Stevenson HC, Stevenson GW (1987) Adoptive cellular cancer immunotherapy. In:Oldham RK (ed) Principals of cancer biotherapy. Raven, New York, pp 385–397Google Scholar
- 3.Plas A, de Witte T, Wessels H, Haanen C (1988) A new multichamber counterflow centrifuge rotor with high-separation capacity and versatile potentials. Exp Hematol 16:355–359Google Scholar
- 5.Adams DO, Edelson PJ, Koren H (eds) (1981) Methods for studying mononuclear phagocytes. Academic, New YorkGoogle Scholar
- 7.Old LJ (1988) Tumor necosis factor. Sci Am May:41–49Google Scholar