Evaluation of Biologic Activity of Attenuated Endotoxin in Mice.

摘要

Bacterial endotoxins increase nonspecific host resistance to a number of stresses. For example, resistance to radiation-induced damage is achieved through stimulation of granulocytic proliferation by endotoxin. Endotoxin is also a B-lymphocyte mitogen and thus has been used as an adjuvant for promoting resistance to antigens such as cancer cell implants. Repeated small doses of endotoxin, furthermore, can be used to establish a refractory state (tolerance) to further challenge with endotoxin. All of the resistance enhancing actions of endotoxin described above may contribute to the ability of endotoxin to increase resistance to bacterial infections. Experiments were designed to test the hypothesis that Salmonella typhosa endotoxin could be attenuated by treatment with ferric chloride (FeCl3) and that this preparation retained the biological activity of normal endotoxin. The authors found attenuated endotoxin to be as biologically active as untreated endotoxin, but it had the additional advantage of being relatively nontoxic.