ENZYMATIC BIOSENSORS CAN DISCRIMINATE BETWEEN FOOT-AND-MOUTH DISEASE VIRUS INFECTED AND VACCINATED ANIMALS

MARÍA T. SÁNCHEZ; MARÍA R. FERRAZ; LAURA DELGUI; ESTHER BLANCO; ANTONIO VILLAVERDE; MARÍA F. ROSAS; FRANCISCO SOBRINO

Barcelona

Encuentro; XV Meeting European Study Group On The Molecular Biology Of Picornaviruses; 2008

Organised by Albert Bosch & Esteban Domingo

Detection of infection-specific antibodies is a key issue for the control of foot-and-mouth disease virus (FMDV), which causes one of the most damaging and feared animal diseases. Antibodies to FMDV NS proteins, mainly those to the 3AB region, have been shown to permit specific serological distinction between infected and conventionally vaccinated animals, by standard techniques. Biosensors constitute a promising tool as they can allow development of rapid and species-independent diagnostic tests. We previously showed that insertion of multiple FMDV peptides, corresponding to an important B cell site in capsid protein VP1, near to the active site of recombinant β–galactosidase, dramatically increase the enzymatic responsiveness to specific anti-peptide antibodies, including sera from infected animals. Here, we report that recombinant β–galactosidases accommodating per monomer, at one or two insertion sites, sequences from the FMDV NS protein 3B, can be reactivated by MAbs to this protein. Interestingly, these recombinant β–galactosidases, particularly those incorporating a single copy of each of two different 3B sequences, could be efficiently reactivated by sera from infected animals. Enzymatic reaction conditions have been optimized as to allow differentiation between infected sera and those from naïve or conventionally vaccinated animals, providing the basis for further developments.