An innovative approach in the detection of Toxocara canis excretory/secretory antigens using specific nanobodies.

An innovative approach in the detection of Toxocara canis excretory/secretory antigens using specific nanobodies. Int J Parasitol. 2019 May 28;: Authors: Morales-Yanez FJ, Sariego I, Vincke C, Hassanzadeh-Ghassabeh G, Polman K, Muyldermans S Abstract Human toxocariasis is a zoonosis resulting from the migration of larval stages of the dog parasite Toxocara canis into the human paratenic host. Despite its well-known limitations, serology remains the most important tool to diagnose the disease. Our objective was to employ camelid single domain antibody fragments also known as nanobodies (Nbs) for a specific and sensitive detection of Toxocara canis excretory/secretory (TES) antigens. From an alpaca immune Nb library, we retrieved different Nbs with specificity for TES antigens. Based on ELISA experiments, these Nbs did not show any cross-reactivity with Ascaris lumbricoides, Ascaris suum, Pseudoterranova decipiens, Anisakis simplex and Angiostrongylus cantonensis larval antigens. Western blot and immunocapturing revealed that Nbs 1TCE39, 1TCE52 and 2TCE49 recognize shared epitopes on different components of TES antigen. The presence of disulphide bonds in the target antigen seems to be essential for recognition of the epitopes by these three Nbs. Three separate sandwich ELISA formats, using monovalent and bivalent Nbs, were assessed to maximize the detection of TES antigens in solution. The combination of biotinylated, bivalent Nb 2TCE...
Source: International Journal for Parasitology - Category: Parasitology Authors: Tags: Int J Parasitol Source Type: research