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Effects of inactivated streptococci (OK-432) on macrophage functions in mice
Abstract:
The effects of inactivated streptococci (OK-432) on murine macrophage functions were investigated. In vivo treatment of peritoneal macrophages with OK-432 augmented the direct cytotoxic activity against TU5 tumor cells in a 48 h tritiated thymidine release assay. OK-432 also stimulated the rapid (6 h, 51Cr release) macrophage-mediated killing of Actinomycin D-sensitized WEHI 164 sarcoma cells. Moreover, the expression of la antigens on peritoneal macrophages was found to be greatly enhanced after in vivo treatment with OK-432. The immunomodulatory effects of OK-432 on macrophages functions may contribute to the antitumor activity of inactivated streptococci.
Insights
Inactivated streptococci (OK-432) enhance macrophage cytotoxic activity against tumor cells and increase la antigen expression. These immunomodulatory effects suggest OK-432
Area of Science:
- Immunology
- Oncology
- Microbiology
Background:
- Macrophage functions are crucial in host defense and tumor surveillance.
- Inactivated bacterial preparations are explored for immunomodulatory and anti-tumor potential.
Purpose of the Study:
- To investigate the impact of inactivated streptococci (OK-432) on murine macrophage functions.
- To assess OK-432's influence on macrophage-mediated cytotoxicity and antigen expression.
Main Methods:
- In vivo administration of OK-432 to mice.
- Peritoneal macrophages were isolated and assessed for cytotoxic activity using 48h tritiated thymidine release assay against TU5 tumor cells.
- Macrophage-mediated killing of Actinomycin D-sensitized WEHI 164 sarcoma cells was measured via 6h 51Cr release assay.
- Expression of la antigens on macrophages was analyzed.
Main Results:
- OK-432 treatment augmented direct cytotoxic activity of macrophages against TU5 tumor cells.
- OK-432 stimulated rapid macrophage-mediated killing of Actinomycin D-sensitized WEHI 164 sarcoma cells.
- In vivo OK-432 treatment significantly enhanced the expression of la antigens on peritoneal macrophages.
Conclusions:
- Inactivated streptococci (OK-432) modulate murine macrophage functions, enhancing their cytotoxic capabilities.
- OK-432 upregulates la antigen expression on macrophages, potentially improving antigen presentation.
- The immunomodulatory effects of OK-432 on macrophages may underlie its observed anti-tumor activity.