Immunogenicity of foot-and-mouth disease virus structural polyprotein P1 expressed in transgenic rice

Analysis of Foot and Mouth Disease Virus Polyprotein for Multi Peptides Vaccine Design: An In silico Strategy

Foot-and-mouth disease virus (FMDV) is small RNA virus from Picornaviridae family; genus Aphthovirus. FMDV causes maximum levels of infectivity in cattle and harmful socioeconomic effects. The present report attempted to design vaccine candidate from the polyprotein of FMDV to stimulate protective immune response. The IEDB server was used to predict B and T cells epitopes that were linked via GPGPG and YAA linkers, respectively. Mycobacterium tuberculosis 50S ribosomal protein was exploited as an adjuvant and a six histidine-tag sequence was linked to the carboxyl end of the vaccine for purification and identification. The predicted vaccine comprised 313aa and was antigenic and not allergic. Moreover, the vaccine was acidic and showed stability and hydrophilicity. Vaccine secondary and tertiary structures were predicted. The tertiary structure was refined to ameliorate the quality of the global and local structures of the vaccine. Vaccine model validation was performed and the final quality score of the structural model was computed. The validated model was used for molecular docking with bovine (N*01801-BoLA-A11) allele. Docking process in terms of binding free energy score was significant. Vaccine solubility was investigated based on the protein of E. coli and the stability was based on the disulfide bonding to lessen the entropic and mobile points in vaccine. Lastly, the in silico cloning ensured the proper cloning and best translation of the DNA of vaccine in molecular vectors.

Immunogenic profiling and designing of a novel vaccine from capsid proteins of FMDV serotype Asia-1 through reverse vaccinology

Foot-and-mouth disease is one of the devastating transboundary animal diseases causing heavy losses to the livestock industry. Different vaccines based on the inactivated FMD virus are used against this disease, but lack of immunological memory and the need for high biocontainment are the major drawbacks of these vaccines. A novel vaccine comprising recombinant antigenic regions is effective, as they lack viruses for production. Considering the fact, capsid proteins vp4, vp2, vp3, and vp1 with 3C protease of FMDV serotype Asia-1 were analyzed through reverse vaccinology approaches in this study. The sequence and structural analysis of the proteins is carried out through various bioinformatic tools and the sequence analysis has figured out the acidic nature and thermal stability of the proteins, likewise, the phylogenetic analysis helped us to trace the FMDV isolates, elucidating that selected proteins belong to the strain (Group VII), which is currently circulating in Pakistan. Next, the B-cell and MHC Class-I epitopes are identified from the antigenic proteins by immunoinformatic tools. The highly conserved, antigenic, and non-allergenic epitopes are used to design the vaccine. Accordingly, the codon adaptation and in silico cloning of the corresponding genes is performed. Thus, the bacterial expression vector could be used for efficient expression and large-scale production of the vaccine.

The potential of plant-made vaccines to fight picornavirus

INTRODUCTION

Several Picornaviruses are pathogens that generate serious problems for human and animal health worldwide. Vaccination is an attractive approach to fight against picornaviruses. In this regard, the development of low-cost vaccines is a priority to ensure coverage; especially in developing and low-income countries. In this context, plant-made vaccines are a convenient technology since plant cells are low-cost bioreactors capable of producing complex antigens that preserve their antigenic determinants; moreover, they can serve as biocapsules to achieve oral delivery.

AREAS COVERED

In the present review the advances in the development of plant-made vaccines against picornaviruses are summarized and placed in perspective. The main diseases that have been targeted using this approach include Poliovirus, Food and mouth disease virus, Hepatitis A virus, and Enterovirus 71.

EXPERT OPINION

Several vaccine candidates against picornavirus have been characterized at the preclinical level; with many of them capable of inducing humoral and cellular responses that led to neutralization of pathogens when evaluated in vitro and test animal challenge assays. Plant-made vaccines are a promise to fight picornaviruses; especially in the developing world where limited resources hamper vaccination coverage. A critical analysis of the road ahead for this technology is provided.

Minimally processed crude leaf extracts of Nicotiana benthamiana containing recombinant foot and mouth disease virus-like particles are immunogenic in mice

Foot-and-mouth disease (FMD) remains one of the most feared viral diseases affecting cloven-hoofed animals, and results in severe economic losses. Currently available vaccines are based on inactivated FMD virus (FMDV). The use of recombinant FMDV-like particles (VLPs) as subunit vaccines has gained importance because of their immunogenic properties and safety. We evaluated the production of FMD VLPs, via Agrobacterium-mediated transient expression, and the immunogenicity of these structures in mice. Leaves were infiltrated with pEAQ-HT and pRIC 3.0 vectors encoding the capsid precursor P1-2A and the protease 3C. The recombinant protein yield was 3-4 mg/kg of fresh leaf tissue. Both groups of mice immunized with purified VLPs and mice immunized with the crude leaf extract elicited a specific humoral response with similar antibody titers. Thus, minimally processed plant material containing transiently expressed FMD VLPs could be a scalable and cost-effective technology for the production of a recombinant subunit vaccine against FMDV.

Plant-based oral vaccines against zoonotic and non-zoonotic diseases

The shared diseases between animals and humans are known as zoonotic diseases and spread infectious diseases among humans. Zoonotic diseases are not only a major burden to livestock industry but also threaten humans accounting for >60% cases of human illness. About 75% of emerging infectious diseases in humans have been reported to originate from zoonotic pathogens. Because antibiotics are frequently used to protect livestock from bacterial diseases, the development of antibiotic-resistant strains of epidemic and zoonotic pathogens is now a major concern. Live attenuated and killed vaccines are the only option to control these infectious diseases and this approach has been used since 1890. However, major problems with this approach include high cost and injectable vaccines is impractical for >20 billion poultry animals or fish in aquaculture. Plants offer an attractive and affordable platform for vaccines against animal diseases because of their low cost, and they are free of attenuated pathogens and cold chain requirement. Therefore, several plant-based vaccines against human and animals diseases have been developed recently that undergo clinical and regulatory approval. Plant-based vaccines serve as ideal booster vaccines that could eliminate multiple boosters of attenuated bacteria or viruses, but requirement of injectable priming with adjuvant is a current limitation. So, new approaches like oral vaccines are needed to overcome this challenge. In this review, we discuss the progress made in plant-based vaccines against zoonotic or other animal diseases and future challenges in advancing this field.

The Last Ten Years of Advancements in Plant-Derived Recombinant Vaccines against Hepatitis B

Disease prevention through vaccination is considered to be the greatest contribution to public health over the past century. Every year more than 100 million children are vaccinated with the standard World Health Organization (WHO)-recommended vaccines including hepatitis B (HepB). HepB is the most serious type of liver infection caused by the hepatitis B virus (HBV), however, it can be prevented by currently available recombinant vaccine, which has an excellent record of safety and effectiveness. To date, recombinant vaccines are produced in many systems of bacteria, yeast, insect, and mammalian and plant cells. Among these platforms, the use of plant cells has received considerable attention in terms of intrinsic safety, scalability, and appropriate modification of target proteins. Research groups worldwide have attempted to develop more efficacious plant-derived vaccines for over 30 diseases, most frequently HepB and influenza. More inspiring, approximately 12 plant-made antigens have already been tested in clinical trials, with successful outcomes. In this study, the latest information from the last 10 years on plant-derived antigens, especially hepatitis B surface antigen, approaches are reviewed and breakthroughs regarding the weak points are also discussed.

New Strategies Toward Edible Vaccines: An Overview

With the ever growing population, advancements in edible vaccines and related technologies have seen a rise in popularity. Antigenic peptides incorporated into an edible part of a plant can be administered raw as a vaccine. While conventional vaccines have improved the quality of life by drastically reducing the onset of diseases, edible vaccines are able to perform the same with greater accessibility and at an affordable price. Low cost of production, ease of storage, transportation and administration are some of the many reasons behind the push for the development of edible vaccines. This article aims at giving an overview of the different plant systems used to produce vaccines in various experiments, as well as the merits and demerits of using that particular expression system. Further, the article elaborates on the problems faced in the production of edible vaccines and the measures adopted to surpass them. The major obstacle in the process is attaining a sufficiently large concentration of foreign antigen in the plant system. The article discusses various plant expression systems like banana, rice, alfalfa, mushroom, potato, tomato, pea, tobacco, and maize. When these were reviewed, it was found that the inability to produce the desired antigen concentration was one of the primary reasons why edible vaccines sometimes fail to generate the desired level of immune response in the recipient. We conclude with a promising solution to the problem by incorporating nano-technological advancements to the already existing protocols for edible vaccine development.

Plant-produced viral bovine vaccines: what happened during the last 10 years?

Vaccination has proved to be an efficient strategy to deal with viral infections in both human and animal species. However, protection of cattle against viral infections is still a major concern in veterinary science. During the last two decades, the development of efficient plant-based expression strategies for recombinant proteins prompted the application of this methodology for veterinary vaccine purposes. The main goals of viral bovine vaccines are to improve the health and welfare of cattle and increase the production of livestock, in a cost-effective manner. This review explores some of the more prominent recent advances in plant-made viral bovine vaccines against foot-and-mouth disease virus (FMDV), bovine rotavirus (BRV), bovine viral diarrhoea virus (BVDV), bluetongue virus (BTV) and bovine papillomavirus (BPV), some of which are considered to be the most important viral causative agents of economic loss in cattle production.

Mucosal Vaccines from Plant Biotechnology

The use of plants for production of recombinant proteins has evolved over the past 25 years. The first plant-based vaccines were expressed in stably transgenic plants, with the idea to conveniently deliver “edible vaccines” by ingestion of the antigen-containing plant material. These systems provided a proof of concept that oral delivery of vaccines in crude plant material could stimulate antigen-specific serum and mucosal antibodies. Transgenic grains like rice in particular provide a stable and robust vehicle for antigen delivery. However, some issues exist with stably transgenic plants, including relatively low expression levels and regulatory issues. Thus, many recent studies use transient expression with plant viral vectors to achieve rapid high expression in Nicotiana benthamiana, followed by purification of antigen and intranasal delivery for effective stimulation of mucosal immune responses.

Transgenic plants: a 5-year update on oral antipathogen vaccine development

The progressive interest in transgenic plants as advantageous platforms for the production and oral delivery of vaccines has led to extensive research and improvements in this technology over recent years. In this paper, the authors examine the most significant advances in this area, including novel approaches for higher yields and better containment, and the continued evaluation of new vaccine prototypes against several infectious diseases. The use of plants to deliver vaccine candidates against viruses, bacteria, and eukaryotic parasites within the last 5 years is discussed, focusing on innovative expression strategies and the immunogenic potential of new vaccines. A brief section on the state of the art in mucosal immunity is also included.

Novel transgenic rice-based vaccines

Oral vaccination can induce both systemic and mucosal antigen-specific immune responses. To control rampant mucosal infectious diseases, the development of new effective oral vaccines is needed. Plant-based vaccines are new candidates for oral vaccines, and have some advantages over the traditional vaccines in cost, safety, and scalability. Rice seeds are attractive for vaccine production because of their stability and resistance to digestion in the stomach. The efficacy of some rice-based vaccines for infectious, autoimmune, and other diseases has been already demonstrated in animal models. We reported the efficacy in mice, safety, and stability of a rice-based cholera toxin B subunit vaccine called MucoRice-CTB. To advance MucoRice-CTB for use in humans, we also examined its efficacy and safety in primates. The potential of transgenic rice production as a new mucosal vaccine delivery system is reviewed from the perspective of future development of effective oral vaccines.