Enterotoxin type B
In the field of molecular biology, enterotoxin type B, also known as Staphylococcal enterotoxin B (SEB), is an enterotoxin produced by the gram-positive bacteria Staphylococcus aureus. It is a common cause of food poisoning, with severe diarrhea, nausea and intestinal cramping often starting within a few hours of ingestion.
Being quite stable, the toxin may remain active even after the contaminating bacteria are killed. It can withstand boiling at 100 °C for a few minutes.
Gastroenteritis occurs because SEB is a superantigen, causing the immune system to release a large amount of cytokines that lead to significant inflammation.
Additionally, this protein is one of the causative agents of toxic shock syndrome.
The effects of Staphylococcal enterotoxin B (SEB) on regulation of immune response have been recognized; whether SEB can enhance the effects of immunotherapy on glioma remains to be investigated.
A study tests a hypothesis that administration with SEB enhances the effects of specific immunotherapy on glioma growth in mice. In this study, a glioma-bearing mouse model was developed by adoptive transfer with GL261 cells (a mouse glioma cell line). The mice were treated with the GL261 cell extracts (used as an Ag) with or without administration of SEB.
Zheng et al observed that treating glioma-bearing mice with the glioma Ag and SEB induced glioma-specific Th9 cells in both glioma tissue and the spleen. Treating CD4+ CD25- T cells with SEB increased p300 phosphorylation, histone H3K4 acetylation at the interleukin (IL)-9 promoter locus, and increased the IL-9 transcriptional factor binding to the IL-9 promoter. Treating CD4+ CD25- T cells with both SEB and glioma Ag induced glioma-specific Th9 cells. The glioma-specific Th9 cells induced glioma cell apoptosis in the culture. Treating the glioma-bearing mice with SEB and glioma Ag significantly inhibited the glioma growth. In conclusion, SEB plus glioma Ag immunotherapy inhibits the experimental glioma growth, which may be a novel therapeutic remedy for the treatment of glioma 1).