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Research on the production site of tumor necrosis factor (TNF)
Abstract:
Tumor Necrosis Factor (TNF) is an active component of serum taken from Corynebacterium parvum (C. parvum) infected mice treated with lipopolysaccharide (LPS). To locate the production site of TNF, we tried to block TNF production by using the following reagents; carrageenan, hydrocortisone, and trypan blue. Following the injection of a large dose of carrageenan, administered before C. parvum treatment, TNF production was completely blocked. However, when administered after C. parvum treatment but prior to LPS injection, no blockage was observed. Injecting hydrocortisone before the LPS injection also blocked TNF release. However, this treatment, when administered before the injection of C. parvum, had no observable influence on TNF production. A large dose of trypan blue, administered before the LPS injection, also blocked the release of TNF. A low dose of trypan blue resulted in only partial blockage of TNF production. A large dose of trypan blue, administered prior to C. parvum treatment, also showed partial blockage of TNF production. Macrophage-enriched peritoneal exudate cells (PEC), taken from mice infected with C. parvum, released TNF into the supernatant after stimulation with LPS. These results strongly suggest that the production site of TNF is located within the activated macrophage and deeply related with lysosome.
Insights
Tumor Necrosis Factor (TNF) production in mice is blocked by carrageenan, hydrocortisone, and trypan blue, indicating activated macrophages are the primary site. These findings link TNF release to lysosomal activity in macrophages.
Area of Science:
- Immunology
- Cell Biology
Background:
- Tumor Necrosis Factor (TNF) is a key component in serum from mice infected with Corynebacterium parvum (C. parvum) and treated with lipopolysaccharide (LPS).
- Identifying the cellular source of TNF is crucial for understanding immune responses.
Purpose of the Study:
- To investigate the production site of TNF in C. parvum-infected mice treated with LPS.
- To elucidate the role of specific reagents in modulating TNF production.
Main Methods:
- Mice were treated with C. parvum and LPS, with interventions including carrageenan, hydrocortisone, and trypan blue at various stages.
- TNF production was assessed by blocking agents.
- Macrophage-enriched peritoneal exudate cells (PEC) were isolated and stimulated with LPS in vitro.
Main Results:
- Carrageenan, hydrocortisone, and trypan blue effectively blocked TNF production when administered at specific time points relative to C. parvum and LPS treatments.
- Hydrocortisone blocked TNF release when given before LPS but not before C. parvum.
- Macrophage-enriched PEC from C. parvum-infected mice released TNF upon LPS stimulation.
Conclusions:
- These findings strongly suggest that activated macrophages are the primary production site of TNF.
- TNF production is closely associated with lysosomal activity within macrophages.