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Published on: March 9, 2016
[Activity of Enterococcus faecalis (FK-23) preparation as a biological response modifier]
1Research Institute, Nichinichi Food Co., Mie, Japan.
Abstract:
The biological activity of a preparation of heat killed cells of Enterococcus faecalis, FK-23 which was isolated from the feces of a healthy human, was investigated in C3H/He mice. Intraperitoneal injection of the preparation caused an accumulation of neutrophils and macrophages in the peritoneal cavity of the mice 6 h later. As a parameter of the activation of macrophages, the effect of the FK-23 preparation on the production of tumor necrosis factor (TNF) was examined. The mice were given two consecutive intravenous injections of the preparation at a dose of 10 micrograms/mouse and, 3 h later, of 300 micrograms/mouse. The TNF level in the sera reached 99 U/ml in mice 2 h after the second injection. This preparation also stimulated peritoneal macrophages to produce TNF in vitro and increased the capacity of neutrophils to adhere to plastic plates and to release active oxygens, but did not induce blastogenic transformation of lymphocytes. These results suggest that the FK-23 preparation is a biological response modifier (BRM) with various activities on phagocytes similar to a streptococcal antitumor agent, OK432.
Insights
Heat-killed Enterococcus faecalis FK-23 immune preparation activates macrophages and neutrophils in mice. This biological response modifier (BRM) shows potential for immune modulation, similar to OK432.
Area of Science:
- Immunology
- Microbiology
Context:
- Enterococcus faecalis FK-23, a heat-killed bacterial preparation isolated from human feces, was investigated for its biological activities.
- The study utilized a mouse model (C3H/He mice) to assess the in vivo and in vitro effects of FK-23.
Purpose:
- To investigate the biological activity and immune-modulating effects of the Enterococcus faecalis FK-23 preparation.
- To evaluate FK-23's impact on phagocyte activation, specifically neutrophils and macrophages, and cytokine production.
Summary:
- Intraperitoneal injection of FK-23 led to neutrophil and macrophage accumulation in mouse peritoneal cavities.
- FK-23 stimulated macrophages to produce tumor necrosis factor (TNF) in vitro and in vivo, with serum TNF levels reaching 99 U/ml.
- The preparation enhanced neutrophil adherence and active oxygen release but did not induce lymphocyte blastogenesis.
Impact:
- These findings suggest FK-23 acts as a biological response modifier (BRM) with significant phagocyte-activating properties.
- The immune activities observed are comparable to those of the streptococcal antitumor agent OK432, indicating potential therapeutic applications.
