The corn smut (‘Huitlacoche’) as a new latform for oral vaccines

"The development of new alternative platforms for subunit vaccine production is a priority in the biomedical field. In this study, Ustilago maydis, the causal agent of common corn smut or 'huitlacoche' has been genetically engineered to assess expression and immunogenicity of the B subunit of the cholera toxin (CTB), a relevant immunomodulatory agent in vaccinology. An oligomeric CTB recombinant protein was expressed in corn smut galls at levels of up to 1.3 mg g(-1) dry weight (0.8% of the total soluble protein). Mice orally immunized with 'huitlacoche'-derived CTB showed significant humoral responses that were well-correlated with protection against challenge with the cholera toxin (CT). These findings demonstrate the feasibility of using edible corn smut as a safe, effective, and low-cost platform for production and delivery of a subunit oral vaccine. The implications of this platform in the area of molecular pharming are discussed.

Revista Iberoamericana de Micología Huitlacoche (corn smut), caused by the phytopathogenic fungus Ustilago maydis, as a functional food

a b s t r a c t Background: In recent years the need has arisen to study and develop (or re-discover) foods that have nutritional characteristics as well as specific functions, such as improving health and/or reducing the risk of disease. For this reason knowledge of the nutritional value of food is important to promote greater consumer acceptance. In Mexico huitlacoche (also, cuitlacoche) has traditionally been prized as a delicacy since the time of the Aztecs and is currently being studied as a potential functional food and as a producer of natural bioactive substances that are used in fortifying foods. Aims: To present an updated review about the properties of the huitlacoche (corn smut) as functional food. Methods: A bibliographic search was performed and data were discussed. Results: The data of the works reviewed here show that huitlacoche contains many compounds that confer to it unique organoleptic and nutraceutical characteristics. Conclusions: The content of bioactive substances in huitlacoche supports the proposal that this is a good functional food as well as producer of compounds to enrich other foods. © r e s u m e n Antecedentes: Durante los últimos años ha surgido la necesidad de elaborar, estudiar o redescubrir los alimentos que, además de proporcionarnos los beneficios nutricionales que los caracterizan, puedan cumplir una función específica, como mejorar la salud o reducir el riesgo de contraer enfermedades. Por este motivo, el conocimiento del valor nutrimental de los alimentos es importante para que estos tengan una mejor aceptación entre los consumidores. En México, el huitlacoche o cuitlacoche ha sido tradicionalmente apreciado como una delicia culinaria desde la época de los aztecas, y actualmente se está estudiando su potencial como alimento funcional y como productor de sustancias bioactivas naturales, que puedan ser utilizadas en la producción de alimentos fortificados. Objetivos: Presentar una revisión actualizada acerca de las propiedades del huitlacoche (carbón del maíz) como alimento funcional. Métodos: Se realizó una investigación bibliográfica y los datos fueron discutidos. Resultados: Los datos de los trabajos revisados aquí indican que el huitlacoche contiene muchos compuestos que le confieren características organolépticas y nutracéuticas únicas. Conclusiones: El contenido de sustancias bioactivas en el huitlacoche apoya la propuesta de que éste es un buen alimento funcional, además de producir compuestos para enriquecer otros alimentos

Invasive Fungal Infection Caused by Magnusiomyces capitatus in an Immunocompromised Pediatric Patient with Acute Lymphoblastic Leukemia in Mexico City: A Case Report

Magnusiomyces capitatus (also denominated “Geotrichum capitatum” and “the teleomorph stage of Saprochaete capitata”) mainly affects immunocompromised patients with hematological malignancies in rare cases of invasive fungal infections (IFIs). Few cases have been reported for pediatric patients with acute lymphoblastic leukemia (ALL), in part because conventional diagnostic methods do not consistently detect M. capitatus in infections. The current contribution describes a systemic infection in a 15-year-old female diagnosed with ALL. She arrived at the Children’s Hospital of Mexico City with a fever and neutropenia and developed symptoms of septic shock 4 days later. M. capitatus ENCB-HI-834, the causal agent, was isolated from the patient’s blood, urine, bile, and peritoneal fluid samples. It was identified with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and a phylogenetic reconstruction using internal transcribed spacer (ITS) and 28S ribosomal sequences. The phylogenetic sequence of M. capitatus ENCB-HI-834 clustered with other M. capitatus-type strains with a 100% identity. In vitro antifungal testing, conducted with the Sensititre YeastOne susceptibility system, found the following minimum inhibitory concentration (MIC) values (μg/mL): posaconazole 0.25, amphotericin B 1.0, fluconazole > 8.0, itraconazole 0.25, ketoconazole 0.5, 5-flucytosine ≤ 0.06, voriconazole 0.25, and caspofungin > 16.0. No clinical breakpoints have been defined for M. capitatus. This is the first clinical case reported in Mexico of an IFI caused by M. capitatus in a pediatric patient with ALL. It emphasizes the importance of close monitoring for a timely and accurate diagnosis of neutropenia-related IFIs to determine the proper treatment with antibiotics, antifungals, and chemotherapy for instance including children with ALL

The corn smut-made cholera oral vaccine is thermostable and induces long-lasting immunity in mouse

"The use of corn smut for the production of recombinant vaccines has been recently implemented by our group. In this study, the stability and immunogenic properties of the corn smut-based cholera vaccine, based on the cholera toxin B subunit (CTB), were determined in mouse. The immunogenic potential of distinct corn smut CTB doses ranging from 1 to 30 ?g were assessed, with maximum humoral responses at both the systemic (IgG) and intestinal (IgA) levels at a dose of 15 ?g. The humoral response last for up to 70 days after the third boost. Mice were fully protected against a challenge with cholera toxin after receiving three 15 ?g-doses. Remarkably, the corn smut-made vaccine retained its immunogenic activity after storage at room temperature for a period of 1 year and no reduction on CTB was observed following exposure at 50 °C for 2 h. These data support the use of the corn smut-made CTB vaccine as a highly stable and effective immunogen and justify its evaluation in target animal models, such as piglet and sheep, as well as clinical evaluations in humans.

Inhibition of polyamine oxidase activity affects tumor development during the maize-Ustilago maydis interaction

Ustilago maydis is a biotrophic plant pathogenic fungus that leads to tumor development in the aerial tissues of its host, Zea mays. These tumors are the result of cell hypertrophy and hyperplasia, and are accompanied by the reprograming of primary and secondary metabolism of infected plants. Up to now, little is known regarding key plant actors and their role in tumor development during the interaction with U. maydis. Polyamines are small aliphatic amines that regulate plant growth, development and stress responses. In a previous study, we found substantial increases of polyamine levels in tumors. In the present work, we describe the maize polyamine oxidase (PAO) gene family, its contribution to hydrogen peroxide (H2O2) production and its possible role in tumor development induced by U. maydis. Histochemical analysis revealed that chlorotic lesions and maize tumors induced by U. maydis accumulate H2O2 to significant levels. Maize plants inoculated with U. maydis and treated with the PAO inhibitor 1,8-diaminooctane exhibit a notable reduction of H2O2 accumulation in infected tissues and a significant drop in PAO activity. This treatment also reduced disease symptoms in infected plants. Finally, among six maize PAO genes only the ZmPAO1, which encodes an extracellular enzyme, is up-regulated in tumors. Our data suggest that H2O2 produced through PA catabolism by ZmPAO1 plays an important role in tumor development during the maize-U. maydis interaction.Fil: Jasso Robles, Francisco Ignacio. Universidad Autónoma de San Luis Potosí. Facultad de Ciencias; MéxicoFil: Jiménez Bremont, Juan Francisco. Instituto Potosino de Investigación Científica y Tecnológica; MéxicoFil: Becerra Flora, Alicia. Instituto Potosino de Investigación Científica y Tecnológica; MéxicoFil: Juárez Montiel, Margarita. Instituto Potosino de Investigación Científica y Tecnológica; MéxicoFil: Gonzalez, Maria Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Pieckenstain, Fernando Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: García de la Cruz, Ramón Fernando. Universidad Autónoma de San Luis Potosí. Facultad de Ciencias Químicas; MéxicoFil: Rodríguez Kessler, Margarita. Universidad Autónoma de San Luis Potosí. Facultad de Ciencias; Méxic

The Corn Smut (‘Huitlacoche’) as a New Platform for Oral Vaccines

<div><p>The development of new alternative platforms for subunit vaccine production is a priority in the biomedical field. In this study, <i>Ustilago maydis</i>, the causal agent of common corn smut or ‘huitlacoche’has been genetically engineered to assess expression and immunogenicity of the B subunit of the cholera toxin (CTB), a relevant immunomodulatory agent in vaccinology. An oligomeric CTB recombinant protein was expressed in corn smut galls at levels of up to 1.3 mg g-1 dry weight (0.8% of the total soluble protein). Mice orally immunized with ‘huitlacoche’-derived CTB showed significant humoral responses that were well-correlated with protection against challenge with the cholera toxin (CT). These findings demonstrate the feasibility of using edible corn smut as a safe, effective, and low-cost platform for production and delivery of a subunit oral vaccine. The implications of this platform in the area of molecular pharming are discussed.</p></div

Antibody levels of BALB/c mice immunized with corn smut galls expressing CTB protein.

<p>Detection of: (a) anti-CTB IgA antibodies in intestinal washes, and (b) anti-CTB IgG antibodies in sera. Mice immunized with different treatments (biomass from ‘huitlacoche’: FB 1 x FB2-CTB 3 and FB1 x FB2 as control) were bled at day 21, and serum was diluted 1:40. Statistical differences versus the WT group are indicated by an asterisk (<i>P</i> < 0.05).</p

Tumors induced on maize plants, after inoculation with FB2-CTB strains paired with FB1 strain.

<p>Leaf tumors induced in 8-day-old maize seedlings inoculated with (a) FB1 x FB2, (b) FB1 x FB2-CTB 3 and (c) FB1 x FB2-CTB 4 crosses. Photos were taken 8 days post-inoculation (dpi). Corn smut galls (‘huitlacoche’) produced by inoculating with (d) FB1 x FB2, (e) FB1 x FB2-CTB 3 and (f) FB1 x FB2-CTB 4 crosses. Plants were grown under greenhouse conditions and photos were taken 18–20 dpi.</p

Immunoprotection against CT challenge of BALB/c mice immunized with galls expressing the CTB protein.

<p>Mice were immunized with either WT galls or FB1 x FB2-CTB 3 galls, and then challenged with CT. Control groups consisted of an unimmunized mice group challenged with CT (PBS/challenged) and an unimmunized unchallenged mice group (unchallenged). Mice were challenged with 10 μg of CT one week following the last boost. After 6 h of CT toxin administration, mice were sacrificed, and fluid accumulation (FA) was estimated by weighing carcass and small intestines. Comparisons between challenged and unchallenged groups have been made, and significant differences found against the unchallenged group are denoted using an asterisk (<i>P</i>< 0.05). Note the lower FA values in the group immunized with FB1 x FB2-CTB 3 galls.</p