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A possible clinical application of multicytokine-producing cytotoxic mononuclear cell (MCCM) therapy
M Katano1, E Kubota, H Yamamoto
1Department of Surgery, Hospital Laboratory, Saga Medical School, Japan.
Abstract:
When peripheral blood mononuclear cells (PBMC) were incubated with a streptococcal preparation, OK-432, for 24 h, PBMC acquired cytolytic activity against cultured and fresh human tumor cells. Such PBMC were called OK-432-activated mononuclear cells (OK-MC). OK-MC produce several kinds of cytokines such as interferon alpha (IFN alpha), IFN gamma, and tumor growth inhibitory factor (TGIF) both in vitro and in vivo. OK-MC-produced cytokines also inhibited the growth of cultured and fresh human tumor cells. The growth inhibition was examined by human tumor clonogenic assay using a double-layer agar technique. The results indicate that two pathways of anti-tumor activity are induced in OK-MC, i.e., cell-mediated and cytokine-mediated.
Insights
Peripheral blood mononuclear cells (PBMC), when treated with OK-432, become activated (OK-MC) and gain the ability to kill human tumor cells. These OK-MC also release cytokines that inhibit tumor growth through cell-mediated and cytokine-mediated pathways.
Area of Science:
- Immunology
- Cancer Biology
- Biotherapy
Background:
- Peripheral blood mononuclear cells (PBMC) are key immune cells.
- Understanding how to activate immune cells against cancer is crucial for developing new therapies.
Purpose of the Study:
- To investigate the anti-tumor activity of PBMC activated by OK-432 (OK-432-activated mononuclear cells, OK-MC).
- To characterize the mechanisms of anti-tumor action induced by OK-MC.
Main Methods:
- Incubation of PBMC with OK-432 for 24 hours.
- Assessing cytolytic activity against cultured and fresh human tumor cells.
- Measuring cytokine production (interferon alpha, interferon gamma, tumor growth inhibitory factor) in vitro and in vivo.
- Evaluating tumor cell growth inhibition using a human tumor clonogenic assay with a double-layer agar technique.
Main Results:
- PBMC incubated with OK-432 acquired significant cytolytic activity against human tumor cells, termed OK-MC.
- OK-MC produced various cytokines, including interferon alpha, interferon gamma, and tumor growth inhibitory factor.
- These cytokines demonstrated inhibitory effects on the growth of both cultured and fresh human tumor cells.
- The study identified two distinct anti-tumor mechanisms: cell-mediated and cytokine-mediated.
Conclusions:
- OK-432 effectively activates PBMC to exert anti-tumor effects.
- OK-MC employ both direct cell killing and cytokine-mediated inhibition to combat tumor growth.
- These findings suggest potential therapeutic applications for OK-432-activated immune cells in cancer treatment.