CHARACTERIZATION OF SINGLE DOMAIN ANTIBODIES DERIVED FROM CAMELIDS (NANOBODIES OR VHH) AGAINST THE STRAIN O1/ CAMPOS OF FOOT-AND-MOUTH DISEASE VIRUS FOR DIAGNOSTIC APPLICATION

BOZZO J; MARCHESE F; MATTION N; GRIPPO V

Mar del Plata

Congreso; REUNION CONJUNTA SAIC SAI SAFIS 2018; 2018

SAIC SAI SAFIS

Foot-and-Mouth Disease (FMD) is a viral disease of livestock with serious economic repercussions. In one hand, development of innovative diagnostic methods for the FMD control is of concern due to the economic importance of susceptible species. In the other hand, camelids present heavy chain only antibodies, so the variable domain consists of a single domain (VHH or nanobody). These antibodies represent a novel tool with unique characteristics conferring great potential in the development of more sensitive diagnostic methods. For this reason, the present work aimed to obtain and characterize VHH specific against FMDV for its application in diagnostic innovation.For this purpose, 32 specific nanobodies against O1/ Campos (O1C) strain were selected by Phage Display methodology. Two immune VHH libraries constructed previously in the laboratory were used as VHH source. These nanobodies showed no reactivity against other FMDV strains (A24/Cruzeiro, A/Arg/2001 and C3/ Indaial) in ELISA. In order to analyze VHH diversity, the most reactive nanobodies in ELISA (17 out of these 32) were analyzed by fingerprinting, showing 12 different patterns. Moreover, we confirmed that 13 out of these 17 VHH were unique by sequencing. These 13 nanobodies were expressed as soluble protein in E. coli WK6 strain. Later, 4 of these VHH were purified from periplasmic extract by IMAC. Reactivity of these soluble antibodies was confirmed by ELISA and Western Blot (WB) against O1C strain and recombinant FMDV structural proteins (SPs). Furthermore, we calculated the IC50 as an indicator of apparent affinity for these nanobodies.In conclusion, we obtained 13 different VHH that showed a high reactivity against O1C strain in ELISA and only two recognized FMDV SPs in WB. Even more, these nanobodies did not react against other FMDV strains. These VHH represent a potential tool for innovation in diagnostic, typification and vaccine quality control of FMDV.