Recently observed in the South-West, the Latrodectus tredecimguttatus is a species of spider better known as the European black widow. Its bites can cause latrodectism, a disease in which the spider’s venom – more precisely a neurotoxin called alpha-latrotoxin – attacks the nervous system and causes intense pain, headaches, nausea or even l hypertension.
If the symptoms of lactrodectism can be effectively treated using antibodies derived from horses, a team of researchers has just developed entirely human antibodies which would make the treatment safer for humans. His work was published in the journal Frontiers in Immunology.
Human antibodies that neutralize black widow neurotoxin
“Many patients bitten by black widows are not fully treated because antivenom is made from horse-derived proteins that are foreign to the human body and can cause unwanted side effects”, such as serum sickness or allergic reactions, we can read in a press release. However, scientists have succeeded in creating, for the first time, in the laboratory, human antibodies capable of neutralizing black widow venom in a cellular test, a “first step to replace horse serums”.
To do this, they used a technique in vitro called “phage exposure” which makes it possible to study the interactions between proteins, peptides and DNA using bacteriophages. “This approach uses extremely diverse gene collections of more than ten billion different antibodies, explain the researchers. From this great diversity of antibodies, we were able to select antibodies that can bind to the desired target, in this case alpha-latrotoxin.”
In total, 45 of the 75 antibodies developed succeeded in eliminating in vitro neurotoxin, but it is a specific candidate, called MRU44-4-A1, which has shown the most promising results and could be the subject of a new therapeutic treatment.
Pending clinical trials of antibodies on humans
Note, however, that only two of the antibodies in question have proven effective against the venom released by other varieties of black widow, such as the Latrodectus mactansfound in North America.
“To develop a potential treatment against all latrotoxins, not just that of the European black widow, we would need ‘cross-reactive’ antibodies [c’est-à-dire spécifiques à plusieurs antigènes] further improved”, says biologist Michael Hust, lead author of the study. He specifies that further research is needed to assess the effectiveness of the antibodies before clinical trials on humans can be launched.
