ABSTRACT
The serum neutralization (SN) test has been regarded as the "gold standard" for seroconversion following foot-and-mouth disease virus (FMDV) vaccination, although a high-level biosafety laboratory is necessary. ELISA is one alternative, and its format is constantly being improved. For instance, standard polyclonal antisera have been replaced by monoclonal antibodies (MAbs) for catching and detecting antibodies, and inactive viruses have been replaced by virus-like particles (VLPs). To the best of current knowledge, however, no researchers have evaluated the performances of different MAbs as tracers. In previous studies, we successfully identified site 1 and site 2 MAbs Q10E and P11A. In this study, following the established screening platform, the VLPs of putative escape mutants from sites 1 to 5 were expressed and used to demonstrate that S11B is a site 3 MAb. Additionally, the vulnerability of VLPs prompted us to assess another diagnostic antigen: unprocessed polyprotein P1. Therefore, we established and evaluated the performance of blocking ELISA (bELISA) systems based on VLPs and P1, pairing them with Q10E, P11A, S11B, and the non-neutralizing TSG MAb as tracers. The results indicated that the VLP paired with S11B demonstrated the highest correlation with the SN titers (R2 = 0.8071, n = 63). Excluding weakly positive serum samples (SN = 16-32, n = 14), the sensitivity and specificity were 95.65% and 96.15% (kappa = 0.92), respectively. Additionally, the P1 pairing with Q10E also demonstrated a high correlation (R2 = 0.768). We also discovered that these four antibodies had steric effects on one another to varying degrees, despite recognizing distinct antigenic sites. This finding indicated that MAbs as tracers could not accurately detect specific antibodies, possibly because MAbs are bulky compared to a protomeric unit. However, our results still provide convincing support for the application of two pairs of bELISA systems: VLP:S11B-HRP and P1:Q10E-HRP.
Subject(s)
Antineoplastic Agents, Immunological , Foot-and-Mouth Disease Virus , Foot-and-Mouth Disease , Animals , Antibodies, Monoclonal , Antibodies, Viral , Enzyme-Linked Immunosorbent Assay/methods , Foot-and-Mouth Disease/diagnosis , Foot-and-Mouth Disease/prevention & control , SwineABSTRACT
Positive-stranded RNA viruses modify host organelles to form replication organelles (ROs) for their own replication. The enteroviral 3A protein has been demonstrated to be highly associated with the COPI pathway, in which factors operate on the ER-to-Golgi intermediate and the Golgi. However, Sar1, a COPII factor exerting coordinated action at endoplasmic reticulum (ER) exit sites rather than COPI factors, is required for the replication of foot-and-mouth disease virus (FMDV). Therefore, further understanding regarding FMDV 3A could be key to explaining the differences and to understanding FMDV's RO formation. In this study, FMDV 3A was confirmed as a peripheral membrane protein capable of modifying the ER into vesicle-like structures, which were neither COPII vesicles nor autophagosomes. When the C-terminus of 3A was truncated, it was located at the ER without vesicular modification. This change was revealed using mGFP and APEX2 fusion constructs, and observed by fluorescence microscopy and electron tomography, respectively. For the other 3A truncation, the minimal region for modification was aa 42-92. Furthermore, we found that the remodeling was related to two COPII factors, Sar1 and Sec12; both interacted with 3A, but their binding domains on 3A were different. Finally, we hypothesized that the N-terminus of 3A would interact with Sar1, as its C-terminus simultaneously interacted with Sec12, which could possibly enhance Sar1 activation. On the ER membrane, active Sar1 interacted with regions of aa 42-59 and aa 76-92 from 3A for vesicle formation. This mechanism was distinct from the traditional COPII pathway and could be critical for FMDV RO formation.
Subject(s)
Foot-and-Mouth Disease Virus , Monomeric GTP-Binding Proteins , Animals , Coat Protein Complex I/metabolism , Endoplasmic Reticulum/metabolism , Foot-and-Mouth Disease Virus/physiology , Golgi Apparatus/metabolism , Monomeric GTP-Binding Proteins/metabolism , Protein Transport/physiologyABSTRACT
In the case of serotype O foot-and-mouth disease virus (FMDV), antibodies against five neutralizing sites play a pivotal role in protection of animals, with site 1 being considered the most crucial. However, recent studies indicated that the antibodies of vaccinated farm animals are mainly against site 2 rather than site 1. In Taiwan, blanket vaccination had been implemented for more than fifteen years, in which the porcinophilic isolate O/Penghu/2012 showed significant amino acid alterations in site 2 compared to the early isolate O/TW/97. To study the antigenicity of site 2, MAbs against site 2 are required. In this study, we generated site 2 mutated virus-like particles (mVLPs) with only VP2-S72â¯N mutation, and successfully identified five site 2 MAbs from a previously prepared O/TW/97 MAb panel by immunofluorescence assay (IFA) and ELISA based on the different reactivity to wild-type VLP and mVLP. In conclusion, the established model was proved as an effective method to reveal the epitope that a MAb recognizes. By applying this MAb panel and sequence alignment, we demonstrated that the O/Penghu/2012 isolate not only showed significant genetic difference in site 2 but also significant antigenic difference from the ancestral O/TW/97.
Subject(s)
Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antigens, Viral/immunology , Foot-and-Mouth Disease Virus/genetics , Foot-and-Mouth Disease Virus/immunology , Foot-and-Mouth Disease/immunology , Mutation , Animals , Antibodies, Viral/immunology , Antigens, Viral/genetics , Epitopes/genetics , Epitopes/immunology , Foot-and-Mouth Disease/epidemiology , Foot-and-Mouth Disease/virology , Neutralization Tests , Swine , Swine Diseases/epidemiology , Swine Diseases/immunology , Swine Diseases/prevention & control , Swine Diseases/virology , Taiwan/epidemiologyABSTRACT
Studies related to healthcare ICT integration in Malaysia are relatively little, thus this paper provide a literature review of the integration of information and communication technologies (ICT) in the healthcare sector in Malaysia through the hospital information system (HIS). Our study emphasized on secondary data to investigate the factors related to ICT integration in healthcare through HIS. Therefore this paper aimed to gather an in depth understanding of issues related to HIS adoption, and contributing in fostering HIS adoption in Malaysia and other countries. This paper provides a direction for future research to study the correlation of factors affecting HIS adoption. Finally a research model is proposed using current adoption theories and external factors from human, technology, and organization perspectives.