Joining the dark side: waterfall spiders in subterranean habitats, with the description of a new genus and two new species from Brazil (Araneae: Trechaleidae)

Posted by
  Joining the dark side: waterfall spiders in subterranean habitats, with the description of a new genus and two new species from Brazil (Araneae: Trechaleidae) Abstract Trechaleidae is a family of spiders often recognized by its semiaquatic species, but its diversity extends beyond these well-known examples. In this study, we describe Troglotrechalea gen. nov. , a new genus with two novel species, T. faleroae spec. nov. and T. agorai spec. nov. , found exclusively in subterranean habitats within karst formations in central and southeastern Brazil. Both species exhibit pale coloration, but unmodified eyes and legs if compared to other species in the family. The slight degree of troglomorphism, along with their geographic and habitat records, suggests that these species are restricted to hypogean habitats, although they probably move through epigean habitats. Additionally, we report in detail the occurrence of the trechaleid genera Enna O. Pickard-Cambridge, 1897, Heidrunea Brescovi...

Evaluation of the immunoprotective power of a multiple antigenic peptide against Aah II toxin of Androctonus australis hector scorpion

Posted by

 


Evaluation of the immunoprotective power of a multiple antigenic peptide against Aah II toxin of Androctonus australis hector scorpion

Abstract

Scorpion envenoming (SE) is a public health problem in developing countries. In Algeria, the population exposed to the risk of SE was estimated at 86.45% in 2019. Thus, the development of a vaccine to protect the exposed population against scorpion toxins would be a major advance in the fight against this disease.

This work aimed to evaluate the immunoprotective effect of a Multiple Antigenic Peptide against the Aah II toxin of Androctonus australis hector scorpion, the most dangerous scorpion species in Algeria. The immunogen MAP1Aah2 was designed and tested accordingly. This molecule contains a B epitope, derived from Aah II toxin, linked by a spacer to a universal T epitope, derived from the tetanus toxin.

The results showed that MAP1Aah2 was non-toxic despite the fact that its sequence was derived from Aah II toxin. The immunoenzymatic assay revealed that the 3 immunization regimens tested generated specific anti-MAP1Aah2 antibodies and cross-reacted with the toxin. Mice immunized with this immunogen were partially protected against mortality caused by challenge doses of 2 and 3 LD50 of the toxin. The survival rate and developed symptoms varied depending on the adjuvant and the challenge dose used. In the in vitro neutralization test, the immune sera of mice having received the immunogen with incomplete Freund’s adjuvant neutralized a challenge dose of 2 LD50.

Hence, the concept of using peptide dendrimers, based on linear epitopes of scorpion toxins, as immunogens against the parent toxin was established. However, the protective properties of the tested immunogen require further optimizations.


Benazzouz, S. M., Benlouahmia, N., Bouhadida, K., Benlamara, M., Arezki, N., El Kheir Sadeddine, O., Issad, M., Attal, N., Mansouri, K., Derrar, F., & Djidjik, R. (2024). Evaluation of the immunoprotective power of a multiple antigenic peptide against Aah II toxin of Androctonus australis hector scorpion. Vaccine: X, 100503. https://doi.org/10.1016/j.jvacx.2024.100503