RESUMEN
Gastrointestinal infections caused by Clostridium difficile lead to significant impact in terms of morbidity and mortality, causing from mild symptoms, such as a low-grade fever, watery stools, and minor abdominal cramping as well as more severe symptoms such as bloody diarrhea, pseudomembrane colitis, and toxic megacolon. Vaccination is a viable approach to fight against C. difficile and several efforts in this direction are ongoing. Plants are promising vaccine biofactories offering low cost, enhanced safety, and allow for the formulation of oral vaccines. Herein, the CdeM protein, which is a spore antigen associated with immunoprotection against C. difficile, was selected to begin the development of plant-based vaccine candidates. The vaccine antigen is based in a fusion protein (LTB-CdeM), carrying the CdeM antigen, fused to the carboxi-terminus of the B subunit of the Escherichia coli heat-labile enterotoxin (LTB) as a mucosal immunogenic carrier. LTB-CdeM was produced in plants using a synthetic optimized gene according codon usage and mRNA stability criteria. The obtained transformed tobacco lines produced the LTB-CdeM antigen in the range of 52-90 µg/g dry weight leaf tissues. The antigenicity of the plant-made LTB-CdeM antigen was evidenced by GM1-ELISA and immunogenicity assessment performed in test mice revealed that the LTB-CdeM antigen is orally immunogenic inducing humoral responses against CdeM epitopes. This report constitutes the first step in the development of plant-based vaccines against C. difficile infection.
Asunto(s)
Antígenos Bacterianos , Clostridioides difficile/genética , Plantas Modificadas Genéticamente , Esporas Bacterianas/genética , Vacunas Comestibles , Administración Oral , Animales , Anticuerpos Antibacterianos/sangre , Antígenos Bacterianos/genética , Antígenos Bacterianos/metabolismo , Enterotoxinas/genética , Proteínas de Escherichia coli/genética , Inmunoglobulina G/sangre , Ratones , Ratones Endogámicos BALB C , Agricultura Molecular , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Nicotiana/genética , Nicotiana/metabolismo , Vacunas Comestibles/genética , Vacunas Comestibles/inmunología , Vacunas Comestibles/metabolismoRESUMEN
This review provides an outlook of the medical applications of immunomodulatory compounds taken from Pleurotus and proposes this fungus as a convenient host for the development of innovative vaccines. Although some fungal species, such as Saccharomyces and Pichia, occupy a relevant position in the biopharmaceutical field, these systems are essentially limited to the production of conventional expensive vaccines. Formulations made with minimally processed biomass constitute the ideal approach for developing low cost vaccines, which are urgently needed by low-income populations. The use of edible fungi has not been explored for the production and delivery of low cost vaccines, despite these organisms' attractive features. These include the fact that edible biomass can be produced at low costs in a short period of time, its high biosynthetic capacity, its production of immunomodulatory compounds, and the availability of genetic transformation methods. Perspectives associated to this biotechnological application are identified and discussed.
Asunto(s)
Biotecnología/métodos , Pleurotus/metabolismo , Tecnología Farmacéutica/métodos , Vacunas Comestibles/metabolismo , Vacunas de Subunidad/metabolismo , Vacunas Sintéticas/metabolismo , Humanos , Pleurotus/genética , Vacunas Comestibles/genética , Vacunas de Subunidad/genética , Vacunas Sintéticas/genéticaRESUMEN
The worldwide need to produce safe and affordable vaccines with a minimum requirement of manufacture and processing, together with the advancements achieved in biotechnology, have promoted the development of efficient alternatives to traditional ones. One of the available options is the use of transgenic plants, not only as a protein production system but as an antigen transportation system as well, being capable of delivering antigens to the mucosal immune targets, becoming what is known as edible vaccines. The versatility of the plant production system allows for instance, to express and to accumulate foreign antigens in edible plant tissues. Thus, the hypothesis for the choice of plant-based vaccines is that once a plant-based vaccine is eaten, the susceptible host mounts a mucosal immune response against the antigen that is expressed in the plant, becoming protected against the pathogen from which the antigen was selected. This idea is still under study. Here, we described the basis of the system, the promising future and the possible drawbacks.