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Updated: Aug 15, 2026
Isolation of Murine Peritoneal Macrophages to Carry Out Gene Expression Analysis Upon Toll-like Receptors Stimulation
Published on: April 29, 2015
Stimulation of various functions in murine peritoneal macrophages by glucans produced by glucosyltransferases from
Inwook Choi1, Gayoung Jo, Seunghyun Kim
1Korea Food Research Institute, Kyunggi-do 463-420, Korea. choiw@kfri.re.kr
Abstract:
The glucan that was produced by glucosyltransferases (GTFs) from Streptococcus mutans was examined for its stimulating functions toward murine peritoneal macrophages. Soluble glucan was obtained by the reaction with cell-free crude GTFs and sucrose, followed by ethanol precipitation, dispersion in water and re-precipitation by ethanol. Soluble glucan, those average molecular weight was about 3 x 10(5), was composed of mixture of alpha-1,6 and alpha-1,3 linkages in a 3:1 ratio. When 30 and 60 microg/ml of the glucan was incubated with peritoneal macrophages, the lysosomal phosphatase activity was increased in a dose-dependent manner, indicating that soluble glucan may activate macrophages. To examine its effects on the various functions of macrophages, soluble glucan was orally administered daily at a level of 100 mg/kg of body weight to C57BL/6 mice. Significant stimulation of the production of H2O2 by the macrophages was observed without any increase in NO production. The production of tumor necrosis factor-alpha (TNF-alpha) by the macrophages was also stimulated from 538.73-555.06 pg/ml to 585.73-596.40 pg/ml during 15 days of oral administration of soluble glucan. The cytotoxicity of peritoneal macrophages against B16 tumor cells was significantly enhanced by 25-38% during 15 days of oral administration. These results may indicate that soluble glucan stimulates the immune functions of macrophages.
Insights
This study shows that soluble glucan from Streptococcus mutans stimulates immune cells. Oral administration of this glucan enhanced macrophage activity and cytotoxicity against tumor cells.
Area of Science:
- Immunology
- Microbiology
- Biochemistry
Background:
- Streptococcus mutans produces glucans via glucosyltransferases (GTFs).
- Glucans can modulate immune responses.
- Investigating the immunomodulatory effects of specific glucan structures is important.
Purpose of the Study:
- To investigate the immune-stimulating functions of soluble glucan produced by Streptococcus mutans GTFs.
- To determine the effects of soluble glucan on murine peritoneal macrophages in vitro and in vivo.
Main Methods:
- Soluble glucan was isolated and characterized (average MW ~3x10^5, alpha-1,6 and alpha-1,3 linkages in 3:1 ratio).
- In vitro assays assessed macrophage lysosomal phosphatase activity, H2O2 production, and TNF-alpha production.
- In vivo studies involved oral administration of soluble glucan to C57BL/6 mice, followed by assessment of macrophage functions and cytotoxicity against B16 tumor cells.
Main Results:
- Soluble glucan increased macrophage lysosomal phosphatase activity in a dose-dependent manner in vitro.
- Oral administration of soluble glucan stimulated H2O2 production by macrophages without increasing NO production.
- Tumor necrosis factor-alpha (TNF-alpha) production and macrophage cytotoxicity against B16 tumor cells were significantly enhanced after 15 days of oral administration.
Conclusions:
- Soluble glucan derived from Streptococcus mutans exhibits immunomodulatory properties.
- The findings suggest that soluble glucan can activate macrophages and enhance their anti-tumor activity.
- Soluble glucan represents a potential therapeutic agent for modulating immune functions.
