TY  - JOUR
PY  - 2022//
TI  - Neutralizing dromedary-derived nanobodies against boti-like toxin from the most hazardous scorpion venom in the Middle East and North Africa region
JO  - Frontiers in immunology
A1  - Ben Abderrazek, Rahma
A1  - Ksouri, Ayoub
A1  - Idoudi, Faten
A1  - Dhaouadi, Sayda
A1  - Hamdi, Emna
A1  - Vincke, Cécile
A1  - Farah, Azer
A1  - Benlasfar, Zakaria
A1  - Majdoub, Hafedh
A1  - El Ayeb, Mohamed
A1  - Muyldermans, Serge
A1  - Bouhaouala-Zahar, Balkiss
SP  - e863012
EP  - e863012
VL  - 13
IS  - 
N2  - Scorpion envenoming is a severe health problem in many regions causing significant clinical toxic effects and fatalities. In the Middle East/North Africa (MENA) region, Buthidae scorpion stings are responsible for devastating toxic outcomes in human. The only available specific immunotherapeutic treatment is based on IgG fragments of animal origin. To overcome the limitations of classical immunotherapy, we have demonstrated the in vivo efficacy of NbF12-10 bispecific nanobody at preclinical level. Nanobodies were developed against BotI analogues belonging to a distinct structural and antigenic group of scorpion toxins, occurring in the MENA region. From Buthus occitanus tunetanus venom, BotI-like toxin was purified. The 41 N-terminal amino acid residues were sequenced, and the LD(50) was estimated at 40 ng/mouse. The BotI-like toxin was used for dromedary immunization. An immune VHH library was constructed, and after screening, two nanobodies were selected with nanomolar and sub-nanomolar affinity and recognizing an overlapping epitope. NbBotI-01 was able to neutralize 50% of the lethal effect of 13 LD(50) BotI-like toxins in mice when injected by i.c.v route, whereas NbBotI-17 neutralized 50% of the lethal effect of 7 LD(50). Interestingly, NbBotI-01 completely reduced the lethal effect of the 2 LD(50) of BotG50 when injected at 1:4 molar ratio excess. More interestingly, an equimolar mixture of NbBotI-01 with NbF12-10 neutralized completely the lethal effect of 7 and 5 LD(50) of BotG50 or AahG50, at 1:4 and 1:2 molar ratio, respectively. Hence, NbBotI-01 and NbF12-10 display synergic effects, leading to a novel therapeutic candidate for treating Buthus occitanus scorpion stings in the MENA region.<p />  <p>Language: en</p>
LA  - en
SN  - 1664-3224
UR  - http://dx.doi.org/10.3389/fimmu.2022.863012
ID  - ref1
ER  -