INVESTIGADORES
GRIPPO vanina
congresos y reuniones científicas
Título:
Feasibility studies of camelid-derived single domain antibodies (VHH or nanobodies)as capture antibodies in a liquid phase blocking ELISA to detect antibodies elicited after FMDV vaccination
Autor/es:
BOZZO J; MARCHESE F; GRIPPO V
Lugar:
Virtual
Reunión:
Congreso; GFRA BA 2021; 2021
Resumen:
Foot and Mouth Disease (FMD) is a viral disease of cloven-hoofed animals with a high economic impact.The potency of the vaccine applied in Argentina is controlled batch-to-batch by Liquid Phase Blocking ELISA. This assay measures specific anti-FMDV antibody (Ab) titers in the serum of vaccinated animals using polyclonal rabbit serum (RS) as capture Ab. On the other hand, camelid-derived single domain Abs (nanobodies or VHH) have revolutionized the field of monoclonal Abs, presenting high specificity and affinity for the antigen (Ag), high stability andproduction yield. The usage of VHH as capture Abs could provide better inter-batch reproducibility and simplify the production. For this reason, we aimed to study the usage of nanobodies (Nbs) in lp-ELISA as capture Abs to detect antibodies elicited in vaccinated bovines.For this purpose, two llamas were immunized with the anti-FMDV vaccine and VHH libraries were constructed from llama blood. Specific VHH against the O1C strain were selected by phage display. The 4 most reactive Nbs were studied to be used as capture Ab in lp-ELISA, using the standardized reagents of ELISA-FLP provided by the Cevan Technical Service. As a result, all 4 VHH were able to capture the Ag.The highest capture level was observed using VHH 2F1 and was comparable to RS. For this reason, VHH 2F1 was studied as the capture Ab in a VHH lp-ELISA and compared to RS lp-ELISA. The Ab titer of 81 sera from vaccinated animals was determined by both ELISA and their concordance was analyzed by the Band-Altman method. The correlation coefficient rendered a value of 0.97 (95%CI=0.98-0.95) with Limits of Agreement (LOA) of 0.2, indicating a high concordance.In conclusion, all 4 Nbs were able to capture O1C strain in ELISA, showing VHH 2F1 the highest capture level. The lp-ELISA using VHH 2F1 as the capture Ab showed comparable results to the RS lp-ELISA. Thus, VHH lp-ELISA has the potential to be used to detect antibodies elicited in bovines by FMDV vaccines.