OBTAINING SPECIFIC ANTIBODIES AGAINST BLACK MAMBA VENOM USING SILICA NANOPARTICLES AS ADJUVANT

FEDERICO G. BAUDOU; MARTÍN DESIMONE; GUILLERMO L. MONTERO; MARÍA HERRERA; FLORENCIA S. CONTI; LAURA LEIVA; MAURICIO DE MARZI

Mar del Plata

Congreso; Reunión Anual de Sociedades de Biociencia 2022; 2022

Reunion conjunta: SAIC, SAI, SAFIS

Ophidism is a global problem that causes approximately 130 thousand deaths per year. In particular, Dendroaspis polylepis (black mamba) has a highly lethal venom (V) due to the presence of Kunitz-type toxins (dendrotoxins) and three finger toxins (3FTXs). Specific antivenom (AV) to avoid fatal accidents are produced by hyperimmunizing animals with V and adjuvants (ADJ). On the other hand, nanoparticles (NPs) have a wide spectrum of application, given their potential therapeutic, immunomodulation and ability to capture antigens and induce specific responses. Hence the interest in associating it with V, replacing classic ADJ such as Freund (F). Here, we generated complexes called nanovenoms (NV) by mixing10 mg of silica NPs (SiOHNPs, diameter=400 nm, negative charge) and 1 mg of whole V from black mamba for 3 h under stirring. Then, we calculated the subcutaneous (SC) LD50 of V and NV in mice (CD-1, 18-22 g, N=5/level) using Probits. In addition, we immunized (5 doses, every 15 days) with V, F-V and NV groups of 5 mice and 3 rabbits (new zealand, 2.8-3.5 kg) (via SC, 5-10 µg V/mouse, 500 µg V/rabbit). At 30 and 60 days we took blood samples and the antibody titter (Ab) was measured in serum for each group by ELISA. At the end, the presence of specific Ab in rabbit crude serum was tested by Western Blot, and the neutralizing potency (ED50) of the lethal activity of V (challenge 1.5 LD50 V, intravenous route, IV) was studied.The LD 50 (µg V/mouse) was V=7.67 (CI=4.76-10.09) and NV=9.95 (CI=2.54-12.16). In mice there was no significant increase in the Ab titter measured by ELISA in the NV group, but in rabbits it was significantly higher compared to F-V (p