The resulting images were imported into Adobe Photoshop for editing

The resulting images were imported into Adobe Photoshop for editing. == Competing interests == The authors declare that they have no competing interests. == Authors contributions == MY: designed all experiments, produced and purified mAbs, performed peptide ELISA, antigenic profiling ELISA and drafted the manuscript. HKN/2/11 exhibited the highest antigenic variation compared to the others. Furthermore, the panel of mAbs was used in vaccine matching by antigenic profiling ELISA with O1/Manisa as the reference strain. However, there was no correlation between vaccine matching by antigenic ELISA and the gold standard method, virus neutralisation test (VNT), for the forty-six FMDV/O isolates. Nine isolates had particularly poor correlation with the reference vaccine strain as revealed by the low r1values in VNT. The amino acid sequences of the outer capsid Revaprazan Hydrochloride proteins for these nine isolates were analyzed and compared with the vaccine strain O1/Manisa. The isolate ECU/4/10 displayed three unique amino acid substitutions around the antigenic sites 1, 3 and 4. == Conclusions == The panel of mAbs is useful to monitor the emergence of antigenically different strains and determination of relevant antigenic site differences. However, for vaccine matching VNT remains the preferred method but a combination of VNT, antigenic profiling with a panel of mAbs and genetic sequencing would probably be more ideal for full characterization of any new outbreak isolates as well as for selection of vaccine strains from FMDV antigen banks. Keywords:Foot-and-mouth disease, Monoclonal antibody, Antigenic site, Vaccine matching == Introduction == Foot-and-mouth disease (FMD) is usually a highly infectious and acute disease that affects cloven-hoofed animals such as cattle, pigs, goats, sheep and deer. Its rapid spread, high morbidity and loss of productivity have severe implications for animal farming which leads to considerable financial losses. For these reasons, the use Revaprazan Hydrochloride of vaccine is usually often favoured to prevent and control FMD. Vaccination was used successfully to help control the FMD outbreak in the Netherlands in 2001 [1]. Vaccination may be an economically optimal strategy, although the questions of where, how, and when to use vaccination for FMD need to be further addressed [2]. Foot-and-mouth disease virus (FMDV) comes in seven serotypes (O, A, C, Asia 1, SAT 1, 2 and 3). Among the seven serotypes of FMDV, O and A are the most widespread. FMD viruses frequently change at different antigenic sites. Within the serotypes, there is considerable antigenic variability [3]. There is no cross-immunity among the seven serotypes. This is evidenced in animals that have previously been infected with one serotype, but remain susceptible to the six other serotypes. Consequently, FMDV-specific antibodies protect only against homologous, but not heterologous FMD outbreaks. Thus, the vaccine selected must be highly specific to the strain involved and matched as closely as possible with the outbreak isolate. It has been indicated that lack of vaccine-induced protection may involve the use of an inadequately matched vaccine [4]. A direct relationship has been shown between the level of serum neutralizing antibody and animal protection [5]. However, selection of the proper vaccine is extremely difficult because of the antigenic variation within FMDV serotypes. In general, methods for vaccine strain selection mainly rely on two in vitro indirect serological methods: (a) virus neutralisation test (VNT) using vaccine strain-specific serum pool [6] and (b) an ELISA using polyclonal antibodies [7]. VNT is more relevant to in vivo protection than other measures [8] and seems to produce the most reproducible inter-laboratory results [9]. Although the neutralisation test Revaprazan Hydrochloride has been widely used for many years, it is time consuming and requires live virus. In addition, the results are inconsistent because of (1) different cells and different sera used and (2) different interpretation of cytopathic effect (CPE) in different laboratories. ELISA, on the other hand, has advantages over VNT because it is rapid and no live virus is required. But the ELISA using polyclonal antibodies is difficult to standardize. Sequence analysis can reveal genetic changes of viruses. Thus it can Rabbit Polyclonal to MOBKL2B reveal the emergence of new strains and may indicate if an outbreak isolate is similar to a vaccine strain [10]. However, the procedure is complicated and takes days to complete. Antigenic profiling ELISA using mAbs provides a fast and more sensitive method for the characterization of field and vaccine strains [11-15]. A rapid and simple method to compare antigenic profiles and characterization of new field isolates has been reported using panels of mAb [16]. However, antibody binding sites were not well-characterized and identified in that study. Thus it is impossible to locate mutations and identify differences among isolates. Mahapatra et al. [17] reported that they were unable to find a correlation between the micro neutralization results and antigenic profiling ELISA using mAbs. Up until now, the information is limited regarding the relationship of.