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BACKGROUND: Highly palatable food triggers behavioral responses including strong motivation. These effects involve the reward system and dopamine neurons, which modulate neurons in the nucleus accumbens (NAc). The molecular mechanisms underlying the long-lasting effects of highly palatable food on feeding behavior are poorly understood. METHODS: We studied the effects of 2-week operant conditioning of mice with standard or isocaloric highly palatable food. We investigated the behavioral responses and dendritic spine modifications in the NAc. We compared the translating messenger RNA in NAc neurons identified by the type of dopamine receptors they express, depending on the kind of food and training. We tested the consequences of invalidation of an abundant downregulated gene, Ncdn. RESULTS: Operant conditioning for highly palatable food increased motivation for food even in well-fed mice. In wild-type mice, free choice between regular and highly palatable food increased weight compared with access to regular food only. Highly palatable food increased spine density in the NAc. In animals trained for highly palatable food, translating messenger RNAs were modified in NAc neurons expressing dopamine D2 receptors, mostly corresponding to striatal projection neurons, but not in neurons expressing D1 receptors. Knockout of Ncdn, an abundant downregulated gene, opposed the conditioning-induced changes in satiety-sensitive feeding behavior and apparent motivation for highly palatable food, suggesting that downregulation may be a compensatory mechanism. CONCLUSIONS: Our results emphasize the importance of messenger RNA alterations in D2 striatal projection neurons in the NAc in the behavioral consequences of highly palatable food conditioning and suggest a modulatory contribution of Ncdn downregulation.
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L-DOPA-induced dyskinesia (LID) is a frequent adverse side effect of L-DOPA treatment in Parkinson's disease (PD). Understanding the mechanisms underlying the development of these motor disorders is needed to reduce or prevent them. We investigated the role of TrkB receptor in LID, in hemiparkinsonian mice treated by chronic L-DOPA administration. Repeated L-DOPA treatment for 10 days specifically increased full-length TrkB receptor mRNA and protein levels in the dopamine-depleted dorsal striatum (DS) compared to the contralateral non-lesioned DS or to the DS of sham-operated animals. Dopamine depletion alone or acute L-DOPA treatment did not significantly increase TrkB protein levels. In addition to increasing TrkB protein levels, chronic L-DOPA treatment activated the TrkB receptor as evidenced by its increased tyrosine phosphorylation. Using specific agonists for the D1 or D2 receptors, we found that TrkB increase is D1 receptor-dependent. To determine the consequences of these effects, the TrkB gene was selectively deleted in striatal neurons expressing the D1 receptor. Mice with TrkB floxed gene were injected with Cre-expressing adeno-associated viruses or crossed with Drd1-Cre transgenic mice. After unilateral lesion of dopamine neurons in these mice, we found an aggravation of axial LID compared to the control groups. In contrast, no change was found when TrkB deletion was induced in the indirect pathway D2 receptor-expressing neurons. Our study suggests that BDNF/TrkB signaling plays a protective role against the development of LID and that agonists specifically activating TrkB could reduce the severity of LID.
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Discinesia Inducida por Medicamentos , Levodopa , Ratones , Animales , Levodopa/toxicidad , Antiparkinsonianos/farmacología , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Dopamina/metabolismo , Receptor trkB/metabolismo , Discinesia Inducida por Medicamentos/metabolismo , Cuerpo Estriado/metabolismo , Ratones Transgénicos , Neuronas Dopaminérgicas/metabolismo , Receptores de Dopamina D2/metabolismo , Oxidopamina/farmacologíaRESUMEN
BACKGROUND: Highly palatable food triggers behavioral alterations reminiscent of those induced by addictive drugs. These effects involve the reward system and dopamine neurons, which modulate neurons in the nucleus accumbens (NAc). The molecular mechanisms underlying the effects of highly palatable food on feeding behavior are poorly understood. METHODS: We studied the effects of 2-week operant conditioning of mice with standard or isocaloric highly palatable food. We investigated the behavioral effects and dendritic spine modifications in the NAc. We compared the translating mRNA in NAc neurons identified by the type of dopamine receptors they express, depending on the type of food and training. We tested the consequences of invalidation of an abundant downregulated gene, Ncdn (Neurochondrin). RESULTS: Operant conditioning for highly palatable food increases motivation for food even in well-fed mice. In control mice, free access to regular or highly palatable food results in increased weight as compared to regular food only. Highly palatable food increases spine density in the NAc. In animals trained for highly palatable food, translating mRNAs are modified in NAc dopamine D2-receptor-expressing neurons, mostly corresponding to striatal projection neurons, but not in those expressing D1-receptors. Knock-out of Ncdn, an abundant down-regulated gene, opposes the conditioning-induced changes in satiety-sensitive feeding behavior and apparent motivation for highly palatable food, suggesting down-regulation may be a compensatory mechanism. CONCLUSIONS: Our results emphasize the importance of mRNA alterations D2 striatal projection neurons in the NAc in the behavioral consequences of highly palatable food conditioning and suggest a modulatory contribution of Ncdn downregulation.
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Dystonia is often associated with functional alterations in the cerebello-thalamic pathways, which have been proposed to contribute to the disorder by propagating pathological firing patterns to the forebrain. Here, we examined the function of the cerebello-thalamic pathways in a model of DYT25 dystonia. DYT25 (Gnal+/-) mice carry a heterozygous knockout mutation of the Gnal gene, which notably disrupts striatal function, and systemic or striatal administration of oxotremorine to these mice triggers dystonic symptoms. Our results reveal an increased cerebello-thalamic excitability in the presymptomatic state. Following the first dystonic episode, Gnal+/- mice in the asymptomatic state exhibit a further increase of the cerebello-thalamo-cortical excitability, which is maintained after θ-burst stimulations of the cerebellum. When administered in the symptomatic state induced by a cholinergic activation, these stimulations decreased the cerebello-thalamic excitability and reduced dystonic symptoms. In agreement with dystonia being a multiregional circuit disorder, our results suggest that the increased cerebello-thalamic excitability constitutes an early endophenotype, and that the cerebellum is a gateway for corrective therapies via the depression of cerebello-thalamic pathways.
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Distonía , Trastornos Distónicos , Animales , Cerebelo , Modelos Animales de Enfermedad , Distonía/genética , Trastornos Distónicos/genética , Ratones , Vías Nerviosas , TálamoRESUMEN
Forebrain dopamine-sensitive (dopaminoceptive) neurons play a key role in movement, action selection, motivation, and working memory. Their activity is altered in Parkinson's disease, addiction, schizophrenia, and other conditions, and drugs that stimulate or antagonize dopamine receptors have major therapeutic applications. Yet, similarities and differences between the various neuronal populations sensitive to dopamine have not been systematically explored. To characterize them, we compared translating mRNAs in the dorsal striatum and nucleus accumbens neurons expressing D1 or D2 dopamine receptor and prefrontal cortex neurons expressing D1 receptor. We identified genome-wide cortico-striatal, striatal D1/D2 and dorso/ventral differences in the translating mRNA and isoform landscapes, which characterize dopaminoceptive neuronal populations. Expression patterns and network analyses identified novel transcription factors with presumptive roles in these differences. Prostaglandin E2 (PGE2) was a candidate upstream regulator in the dorsal striatum. We pharmacologically explored this hypothesis and showed that misoprostol, a PGE2 receptor agonist, decreased the excitability of D2 striatal projection neurons in slices, and diminished their activity in vivo during novel environment exploration. We found that misoprostol also modulates mouse behavior including by facilitating reversal learning. Our study provides powerful resources for characterizing dopamine target neurons, new information about striatal gene expression patterns and regulation. It also reveals the unforeseen role of PGE2 in the striatum as a potential neuromodulator and an attractive therapeutic target.
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Dinoprostona , Misoprostol , Animales , Cuerpo Estriado/metabolismo , Dinoprostona/metabolismo , Dinoprostona/farmacología , Dopamina/metabolismo , Neuronas Dopaminérgicas/metabolismo , Exones , Expresión Génica , Ratones , Misoprostol/metabolismo , Misoprostol/farmacología , ARN Mensajero/metabolismo , Receptores de Dopamina D1/metabolismoRESUMEN
Assembly of the Bacillus subtilis spore coat involves over 80 proteins which self-organize into a basal layer, a lamellar inner coat, a striated electrodense outer coat and a more external crust. CotB is an abundant component of the outer coat. The C-terminal moiety of CotB, SKRB , formed by serine-rich repeats, is polyphosphorylated by the Ser/Thr kinase CotH. We show that another coat protein, CotG, with a central serine-repeat region, SKRG , interacts with the C-terminal moiety of CotB and promotes its phosphorylation by CotH in vivo and in a heterologous system. CotG itself is phosphorylated by CotH but phosphorylation is enhanced in the absence of CotB. Spores of a strain producing an inactive form of CotH, like those formed by a cotG deletion mutant, lack the pattern of electrondense outer coat striations, but retain the crust. In contrast, deletion of the SKRB region, has no major impact on outer coat structure. Thus, phosphorylation of CotG by CotH is a key factor establishing the structure of the outer coat. The presence of the cotB/cotH/cotG cluster in several species closely related to B. subtilis hints at the importance of this protein phosphorylation module in the morphogenesis of the spore surface layers.
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Bacillus subtilis/fisiología , Proteínas Bacterianas/fisiología , Esporas Bacterianas/fisiología , Secuencia de Aminoácidos , Bacillus subtilis/citología , Pared Celular/genética , Pared Celular/metabolismo , Fosforilación , Eliminación de Secuencia , Esporas Bacterianas/citologíaRESUMEN
Abnormal structural and functional connectivity in the striatum during neurological disorders has been reported using functional magnetic resonance imaging (fMRI), although the effects of cell-type specific neuronal stimulation on fMRI and related behavioral alterations are not well understood. In this study, we combined DREADD technology with fMRI ("chemo-fMRI") to investigate alterations of spontaneous neuronal activity. These were induced by the unilateral activation of dopamine D1 receptor-expressing neurons (D1-neurons) in the mouse dorsal striatum (DS). After clozapine (CLZ) stimulation of the excitatory DREADD expressed in D1-neurons, the fractional amplitude of low frequency fluctuations (fALFF) increased bilaterally in the medial thalamus, nucleus accumbens and cortex. In addition, we found that the gamma-band of local field potentials was increased in the stimulated DS and cortex bilaterally. These results provide insights for better interpretation of cell type-specific activity changes in fMRI.
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Cuerpo Estriado/diagnóstico por imagen , Actividad Motora/fisiología , Red Nerviosa/diagnóstico por imagen , Neuronas/fisiología , Animales , Clozapina/farmacología , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/fisiología , Femenino , Imagen por Resonancia Magnética , Masculino , Ratones , Ratones Transgénicos , Actividad Motora/efectos de los fármacos , Red Nerviosa/efectos de los fármacos , Red Nerviosa/fisiología , Neuronas/efectos de los fármacosRESUMEN
Dystonia is a movement disorder characterized by sustained or intermittent muscle contractions and its pathophysiological mechanisms are still poorly understood. Dominant mutations of the GNAL gene are a cause of isolated dystonia (DYT25) in patients. Some mutations result in a complete loss of function of the encoded protein, Gαolf, an adenylyl-cyclase-stimulatory G-protein highly enriched in striatal projection neurons, where it mediates the actions of dopamine and adenosine. We used male and female heterozygous Gnal knock-out mice (Gnal+/-) to study how GNAL haplodeficiency is implicated in dystonia. In basal conditions, no overt dystonic movements or postures or change in locomotor activity were observed. However, Gnal haploinsufficiency altered self-grooming, motor coordination, and apparent motivation in operant conditioning, as well as spine morphology and phospho-CaMKIIß in the striatum. After systemic administration of oxotremorine, an unselective cholinergic agonist, Gnal+/- mice developed more abnormal postures and movements than WT mice. These effects were not caused by seizures as indicated by EEG recordings. They were prevented by the M1-preferring muscarinic antagonists, telenzepine, pirenzepine, and trihexyphenidyl, which alleviate dystonic symptoms in patients. The motor defects were worsened by mecamylamine, a selective nicotinic antagonist. These oxotremorine-induced abnormalities in Gnal+/- mice were replicated by oxotremorine infusion into the striatum, but not into the cerebellum, indicating that defects in striatal neurons favor the appearance of dystonia-like movement alterations after oxotremorine. Untreated and oxotremorine-treated Gnal+/- mice provide a model of presymptomic and symptomatic stages of DYT25-associated dystonia, respectively, and clues about the mechanisms underlying dystonia pathogenesis.SIGNIFICANCE STATEMENT Adult-onset dystonia DYT25 is caused by dominant loss-of-function mutations of GNAL, a gene encoding the stimulatory G-protein Gαolf, which is critical for activation of the cAMP pathway in the striatal projection neurons. Here, we demonstrate that Gnal-haplodeficient mice have a mild neurological phenotype and display vulnerability to developing dystonic movements after systemic or intrastriatal injection of the cholinergic agonist oxotremorine. Therefore, impairment of the cAMP pathway in association with an increased cholinergic tone creates alterations in striatal neuron functions that can promote the onset of dystonia. Our results also provide evidence that untreated and oxotremorine-treated Gnal-haplodeficient mice are powerful models with which to study presymptomic and symptomatic stages of DYT25-associated dystonia, respectively.
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Encéfalo/patología , Encéfalo/fisiopatología , Modelos Animales de Enfermedad , Distonía/patología , Distonía/fisiopatología , Subunidades alfa de la Proteína de Unión al GTP/genética , Animales , Femenino , Heterocigoto , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , MovimientoRESUMEN
Altered synaptic bioactive lipid signaling has been recently shown to augment neuronal excitation in the hippocampus of adult animals by activation of presynaptic LPA2-receptors leading to increased presynaptic glutamate release. Here, we show that this results in higher postsynaptic Ca2+ levels and in premature onset of spontaneous neuronal activity in the developing entorhinal cortex. Interestingly, increased synchronized neuronal activity led to reduced axon growth velocity of entorhinal neurons which project via the perforant path to the hippocampus. This was due to Ca2+-dependent molecular signaling to the axon affecting stabilization of the actin cytoskeleton. The spontaneous activity affected the entire entorhinal cortical network and thus led to reduced overall axon fiber numbers in the mature perforant path that is known to be important for specific memory functions. Our data show that precise regulation of early cortical activity by bioactive lipids is of critical importance for proper circuit formation.
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Axones/fisiología , Señalización del Calcio/fisiología , Ácido Glutámico/metabolismo , Redes y Vías Metabólicas/fisiología , Proyección Neuronal/fisiología , Fosfolípidos/metabolismo , Transmisión Sináptica/fisiología , Animales , Axones/ultraestructura , Calcio/metabolismo , Células Cultivadas , RatonesRESUMEN
The lateral habenula (LHb) encodes aversive signals, and its aberrant activity contributes to depression-like symptoms. However, a limited understanding of the cellular mechanisms underlying LHb hyperactivity has precluded the development of pharmacological strategies to ameliorate depression-like phenotypes. Here we report that an aversive experience in mice, such as foot-shock exposure (FsE), induces LHb neuronal hyperactivity and depression-like symptoms. This occurs along with increased protein phosphatase 2A (PP2A) activity, a known regulator of GABAB receptor (GABABR) and G protein-gated inwardly rectifying potassium (GIRK) channel surface expression. Accordingly, FsE triggers GABAB1 and GIRK2 internalization, leading to rapid and persistent weakening of GABAB-activated GIRK-mediated (GABAB-GIRK) currents. Pharmacological inhibition of PP2A restores both GABAB-GIRK function and neuronal excitability. As a consequence, PP2A inhibition ameliorates depression-like symptoms after FsE and in a learned-helplessness model of depression. Thus, GABAB-GIRK plasticity in the LHb represents a cellular substrate for aversive experience. Furthermore, its reversal by PP2A inhibition may provide a novel therapeutic approach to alleviate symptoms of depression in disorders that are characterized by LHb hyperactivity.
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Conducta Animal/efectos de los fármacos , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Depresión/metabolismo , Canales de Potasio Rectificados Internamente Asociados a la Proteína G/efectos de los fármacos , Habénula/efectos de los fármacos , Desamparo Adquirido , Plasticidad Neuronal/efectos de los fármacos , Piperazinas/farmacología , Proteína Fosfatasa 2/antagonistas & inhibidores , Receptores de GABA-B/efectos de los fármacos , Estrés Psicológico/metabolismo , Animales , Modelos Animales de Enfermedad , Electrochoque , Canales de Potasio Rectificados Internamente Asociados a la Proteína G/genética , Canales de Potasio Rectificados Internamente Asociados a la Proteína G/metabolismo , Habénula/metabolismo , Inmunohistoquímica , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica , Actividad Motora , Técnicas de Placa-Clamp , Fenotipo , Receptores de GABA-B/metabolismo , Restricción Física , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Grooming behaviour is the most common innate behaviour in animals. In rodents, it consists of sequences of movements organized in four phases, executed symmetrically on both sides of the animal and creating a syntactic chain of behavioural events. The grooming syntax can be altered by stress and novelty, as well as by several mutations and brain lesions. Grooming behaviour is known to be affected by alterations of the dopamine system, including dopamine receptor modulation, dopamine alteration in genetically modified animals, and after brain lesion. While a lot is known about the initiation and syntactic modifications of this refined sequence of movements, effects of unilateral lesion of dopamine neurons are unclear particularly regarding the symmetry of syntactic chains. In the present work we studied grooming in mice unilaterally lesioned in the medial forebrain bundle by 6-hydroxydopamine. We found a reduction in completion of grooming bouts, associated with reduction in number of transitions between grooming phases. The data also revealed the development of asymmetry in grooming behaviour, with reduced tendency to groom the contralateral side to the lesion. Symmetry was recovered following treatment with L-DOPA. Thus, the present work shows that unilateral lesion of dopamine neurons reduces self-grooming behaviour by affecting duration and numbers of events. It produces premature discontinuation of grooming chains but the sequence syntax remains correct. This deficient grooming could be considered as an intrinsic symptom of Parkinson's disease in animal models and could present some similarities with abnormalities of motor movement sequencing seen in patients. Our study also suggests grooming analysis as an additional method to screen parkinsonism in animal models.
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Aseo Animal , Animales , Dopaminérgicos/farmacología , Neuronas Dopaminérgicas/patología , Lateralidad Funcional , Levodopa/farmacología , Masculino , Haz Prosencefálico Medial/patología , Ratones Endogámicos C57BL , Enfermedad de Parkinson Secundaria/patología , Enfermedad de Parkinson Secundaria/psicologíaRESUMEN
Located at neuronal terminals, the postsynaptic density (PSD) is a highly complex network of cytoskeletal scaffolding and signaling proteins responsible for the transduction and modulation of glutamatergic signaling between neurons. Using ion-mobility enhanced data-independent label-free LC-MS/MS, we established a reference proteome of crude synaptosomes, synaptic junctions, and PSD derived from mouse hippocampus including TOP3-based absolute quantification values for identified proteins. The final dataset across all fractions comprised 49 491 peptides corresponding to 4558 protein groups. Of these, 2102 protein groups were identified in highly purified PSD in at least two biological replicates. Identified proteins play pivotal roles in neurological and synaptic processes providing a rich resource for studies on hippocampal PSD function as well as on the pathogenesis of neuropsychiatric disorders. All MS data have been deposited in the ProteomeXchange with identifier PXD000590 (http://proteomecentral.proteomexchange.org/dataset/PXD000590).
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Hipocampo/química , Densidad Postsináptica/química , Proteínas/análisis , Proteómica , Animales , RatonesRESUMEN
BACKGROUND: Bacteria of the suborder Corynebacterineae include significant human pathogens such as Mycobacterium tuberculosis and M. leprae. Drug resistance in mycobacteria is increasingly common making identification of new antimicrobials a priority. Mycobacteria replicate intracellularly, most commonly within the phagosomes of macrophages, and bacterial proteins essential for intracellular survival and persistence are particularly attractive targets for intervention with new generations of anti-mycobacterial drugs. METHODOLOGY/PRINCIPAL FINDINGS: We have identified a novel gene that, when inactivated, leads to accelerated death of M. smegmatis within a macrophage cell line in the first eight hours following infection. Complementation of the mutant with an intact copy of the gene restored survival to near wild type levels. Gene disruption did not affect growth compared to wild type M. smegmatis in axenic culture or in the presence of low pH or reactive oxygen intermediates, suggesting the growth defect is not related to increased susceptibility to these stresses. The disrupted gene, MSMEG_5817, is conserved in all mycobacteria for which genome sequence information is available, and designated Rv0807 in M. tuberculosis. Although homology searches suggest that MSMEG_5817 is similar to the serine:pyruvate aminotransferase of Brevibacterium linens suggesting a possible role in glyoxylate metabolism, enzymatic assays comparing activity in wild type and mutant strains demonstrated no differences in the capacity to metabolize glyoxylate. CONCLUSIONS/SIGNIFICANCE: MSMEG_5817 is a previously uncharacterized gene that facilitates intracellular survival of mycobacteria. Interference with the function of MSMEG_5817 may provide a novel therapeutic approach for control of mycobacterial pathogens by assisting the host immune system in clearance of persistent intracellular bacteria.
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Proteínas Bacterianas/genética , Genes Bacterianos/genética , Macrófagos/microbiología , Viabilidad Microbiana/genética , Mycobacterium smegmatis/citología , Mycobacterium smegmatis/genética , Secuencia de Aminoácidos , Animales , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Línea Celular , Elementos Transponibles de ADN/genética , ADN Intergénico/genética , Regulación Bacteriana de la Expresión Génica , Reordenamiento Génico/genética , Marcación de Gen , Prueba de Complementación Genética , Humanos , Espacio Intracelular/microbiología , Macrófagos/citología , Ratones , Datos de Secuencia Molecular , Mutagénesis Insercional/genética , Infecciones por Mycobacterium no Tuberculosas/microbiología , Mycobacterium smegmatis/crecimiento & desarrollo , FN-kappa B/metabolismo , Fagocitosis , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Homología de Secuencia de Aminoácido , Estrés Fisiológico/genéticaRESUMEN
Antigen-specific antibody responses against a model antigen (the B subunit of the heat labile toxin of enterotoxigenic Escherichia coli, LTB) were studied in sheep following oral immunisation with plant-made and delivered vaccines. Delivery from a root-based vehicle resulted in antigen-specific immune responses in mucosal secretions of the abomasum and small intestine and mesenteric lymph nodes. Immune responses from the corresponding leaf-based vaccine were more robust and included stimulation of antigen-specific antibodies in mucosal secretions of the abomasum. These findings suggest that oral delivery of a plant bioencapsulated antigen can survive passage through the rumen to elicit mucosal and systemic immune responses in sheep. Moreover, the plant tissue used as the vaccine delivery vehicle affects the magnitude of these responses.
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Antígenos de Plantas/inmunología , Vacunas Bacterianas/inmunología , Enterotoxinas/genética , Plantas Modificadas Genéticamente/inmunología , Administración Oral , Animales , Vacunas Bacterianas/síntesis química , Vacunas Bacterianas/química , Escherichia coli Enterotoxigénica/inmunología , Enterotoxinas/administración & dosificación , Enterotoxinas/inmunología , Enterotoxinas/metabolismo , Infecciones por Escherichia coli/prevención & control , Inmunidad Celular/efectos de los fármacos , Inmunización/métodos , Inmunización/veterinaria , Masculino , Modelos Teóricos , Mucosa Bucal/efectos de los fármacos , Mucosa Bucal/inmunología , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/metabolismo , Ovinos , Enfermedades de las Ovejas/prevención & controlRESUMEN
As commercial approval of the first, purified, plant-based biopharmaceuticals for parenteral delivery to humans approaches, improved strategies for delivery of plant-made vaccines and therapeutics are required to ensure their further development and to fulfil the prospect of supplying a global solution for affordable medicines. To ensure that this occurs, research should investigate and characterise the host immune system in addition to the effects of adjuvants and carrier vehicles on consistency and efficacy of vaccination. In this review we explore the basic understandings of pharmaceutical delivery and its effect on immunogenicity in an effort to advance the plant-made pharmaceutical platform.
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Plantas Modificadas Genéticamente/genética , Vacunación/métodos , Vacunas/biosíntesis , Adyuvantes Inmunológicos/administración & dosificación , Administración Oral , Animales , Ensayos Clínicos como Asunto , Sistemas de Liberación de Medicamentos , Humanos , Inmunidad Mucosa , Modelos Animales , Plantas Modificadas Genéticamente/metabolismoRESUMEN
This study investigated the site of release of a model vaccine antigen from plant cells and the corresponding induced immune response. Three plant tissues (leaf, fruit and hairy root) and two formulations (aqueous and lipid) were compared in two mouse trials. A developed technique that enabled detection of antigen release by plant cells determined that antigen release occurred at early sites of the gastrointestinal tract when delivered in leaf material and at later sites when delivered in hairy roots. Lipid formulations delayed antigen release from all plant materials tested. While encapsulation in the plant cell provided some protection of the antigen in the gastrointestinal tract and influenced antigen release, formulation medium was also an important consideration with regard to vaccine delivery and immunogenicity. Systemic immune responses induced from the orally delivered vaccine benefited from late release of antigen in the mouse gastrointestinal tract. The influences to the mucosal immune response induced by these vaccines were too complex to be determined by studies performed here with no clear trend regarding plant tissue site of release or formulation medium. Expression and delivery of the model antigen in plant material prepared in an aqueous formulation provided the optimal systemic and mucosal, antigen-specific immune responses.
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Antígenos Bacterianos/administración & dosificación , Toxinas Bacterianas/administración & dosificación , Enterotoxinas/administración & dosificación , Proteínas de Escherichia coli/administración & dosificación , Magnoliopsida , Plantas Modificadas Genéticamente , Vacunas/administración & dosificación , Agrobacterium/genética , Agrobacterium/metabolismo , Animales , Anticuerpos Antibacterianos/sangre , Antígenos Bacterianos/biosíntesis , Antígenos Bacterianos/genética , Infecciones Bacterianas/prevención & control , Toxinas Bacterianas/biosíntesis , Toxinas Bacterianas/genética , Enterotoxinas/biosíntesis , Enterotoxinas/genética , Proteínas de Escherichia coli/biosíntesis , Proteínas de Escherichia coli/genética , Femenino , Tracto Gastrointestinal/inmunología , Inmunidad Mucosa , Inmunoglobulina A/inmunología , Inmunoglobulina G/sangre , Magnoliopsida/genética , Magnoliopsida/metabolismo , Ratones , Ratones Endogámicos C57BL , Hojas de la Planta , Plantas Modificadas Genéticamente/metabolismo , Vacunación/métodosRESUMEN
Interest is growing for the use of plant-made vaccines for veterinary purposes since the regulatory landscape still enables delivery of either crude extracts or minimally processed plant materials to animals for medicinal purposes. In this article, we highlight the current research directions taken with four diseases considered as important constraints to international trade in animals: avian influenza, Newcastle disease, foot-and-mouth disease and diarrheal disease caused by enterotoxigenic Escherichia coli. We also discuss appropriate plant production platforms with regards to plant species and transformation methodologies, possible areas of development, and the remaining challenges for plant-made vaccines for veterinary purposes.