Immunization with a synthetic robustoxin derivative lacking disulphide bridges protects against a potentially lethal challenge with funnel-web spider (Atrax robustus) venom.
The venom of male Atrax robustus spiders is potentially lethal to primates. These spiders have been responsible for a number of human deaths. Robustoxin is the lethal toxin in the venom. It is a highly cross-linked polypeptide that has 42 amino acid residues and four disulphide bridges. If these bridges are broken, the resulting polypeptide is non-toxic. Robustoxin was chemically synthesized with all of its eight cysteine residues protected with acetamidomethyl groups in order to avoid formation of disulphide bridges. The resulting derivative was co-polymerized with keyhole limpet haemocyanin. Two Macaca fascicularis monkeys were immunized with this conjugate. The monkeys were challenged,under anaesthesia,with a potentially lethal dose of male A.robustus crude venom. Both monkeys showed some minor symptoms of intoxication but recovered fully with no adverse after-effects. Immunization with the same immunogen, in the absence of keyhole limpet haemocyanin, did not protect a third monkey. The N-terminal 23 amino acid peptide derived from the sequence of robustoxin was synthesized and conjugated with ovalbumin. A fourth monkey was immunized with this conjugate. However,it was not protected against challenge.The implications of these results for the preparation of synthetic peptide vaccines are discussed.
Comis
Alfio
A
School of Biological and Chemical Sciences, Deakin University, Geelong,Victoria 3217, Australia.
Tyler
Margaret
M
Mylecharane
Ewan
E
Spence
Ian
I
Howden
Merlin
M
D000818:Animals; D008252:Macaca fascicularis / Q000276:immunology*; D008297:Male; D051379:Mice; D009498:Neurotoxins / Q000737:chemistry / Q000276:immunology* / Q000633:toxicity; D001098:Spider Bites / Q000517:prevention & control*; D013111:Spider Venoms / Q000737:chemistry / Q000276:immunology* / Q000633:toxicity; D013112:Spiders / Q000737:chemistry*; D014614:Vaccines, Synthetic / Q000737:chemistry / Q000276:immunology*
D009498:Neurotoxins; D013111:Spider Venoms; D014614:Vaccines, Synthetic; C044536:robustoxin