In vivo protection against scorpion toxins by liposomal immunization.
The possibility of raising a humoral immune response able to induce protection from the lethal effects of scorpion toxins was evaluated in the mouse model. A toxic fraction from the venom of the scorpion Tityus serrulatus was entrapped in sphingomyelin-cholesterol liposomes which yielded a conveniently detoxified immunogen. After three injections of this immunogen, all but three of a group of 18 mice developed an IgG response which was shown to be both specific and of good affinity for the toxic antigen. In vitro neutralization assays indicated that pre-incubation of a lethal dose of the toxic fraction with immune sera strongly diminished its toxicity. In vivo protection assays showed that mice with the highest levels of circulating anti-toxin antibodies could resist the challenge by double the normal LD50 of the toxic fraction, which killed all control non-immune mice. The protection was, however, found to be limited both in its duration and its effectiveness against higher amounts of toxin.
Chavez-Olortegui
C
C
Fundaçao Ezequiel Diaz, Belo Horizonte, Brazil.
Amara
D A
DA
Rochat
H
H
Diniz
C
C
Granier
C
C
D000818:Animals; D000992:Antitoxins / Q000097:blood; D002784:Cholesterol / Q000276:immunology; D002845:Chromatography; D004797:Enzyme-Linked Immunosorbent Assay; D007114:Immunization; D007074:Immunoglobulin G / Q000097:blood; D008081:Liposomes / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009500:Neutralization Tests; D012604:Scorpion Venoms / Q000276:immunology* / Q000633:toxicity; D013109:Sphingomyelins / Q000276:immunology
D000992:Antitoxins; D007074:Immunoglobulin G; D008081:Liposomes; D012604:Scorpion Venoms; D013109:Sphingomyelins; D002784:Cholesterol