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1.
PLoS Genet ; 19(9): e1010893, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37733679

RESUMEN

Brains are highly metabolically active organs, consuming 20% of a person's energy at resting state. A decline in glucose metabolism is a common feature across a number of neurodegenerative diseases. Another common feature is the progressive accumulation of insoluble protein deposits, it's unclear if the two are linked. Glucose metabolism in the brain is highly coupled between neurons and glia, with glucose taken up by glia and metabolised to lactate, which is then shuttled via transporters to neurons, where it is converted back to pyruvate and fed into the TCA cycle for ATP production. Monocarboxylates are also involved in signalling, and play broad ranging roles in brain homeostasis and metabolic reprogramming. However, the role of monocarboxylates in dementia has not been tested. Here, we find that increasing pyruvate import in Drosophila neurons by over-expression of the transporter bumpel, leads to a rescue of lifespan and behavioural phenotypes in fly models of both frontotemporal dementia and Alzheimer's disease. The rescue is linked to a clearance of late stage autolysosomes, leading to degradation of toxic peptides associated with disease. We propose upregulation of pyruvate import into neurons as potentially a broad-scope therapeutic approach to increase neuronal autophagy, which could be beneficial for multiple dementias.


Asunto(s)
Enfermedad de Alzheimer , Demencia Frontotemporal , Humanos , Animales , Demencia Frontotemporal/genética , Enfermedad de Alzheimer/genética , Neuroglía , Ácido Pirúvico , Drosophila , Glucosa
2.
BMC Genomics ; 24(1): 587, 2023 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-37794325

RESUMEN

BACKGROUND: Developing high yielding varieties is a major challenge for breeders tackling the challenges of climate change in agriculture. The panicle (inflorescence) architecture of rice is one of the key components of yield potential and displays high inter- and intra-specific variability. The genus Oryza features two different crop species: Asian rice (Oryza sativa L.) and the African rice (O. glaberrima Steud.). One of the main morphological differences between the two independently domesticated species is the structure (or complexity) of the panicle, with O. sativa displaying a highly branched panicle, which in turn produces a larger number of grains than that of O. glaberrima. The gene regulatory network that governs intra- and interspecific panicle diversity is still under-studied. RESULTS: To identify genetic factors linked to panicle architecture diversity in the two species, we used a set of 60 Chromosome Segment Substitution Lines (CSSLs) issued from third generation backcross (BC3DH) and carrying genomic segments from O. glaberrima cv. MG12 in the genetic background of O. sativa Tropical Japonica cv. Caiapó. Phenotypic data were collected for rachis and primary branch length, primary, secondary and tertiary branch number and spikelet number. A total of 15 QTLs were localized on chromosomes 1, 2, 3, 7, 11 and 12, QTLs associated with enhanced secondary and tertiary branch numbers were detected in two CSSLs. Furthermore, BC4F3:5 lines carrying different combinations of substituted segments were produced to decipher the effects of the identified QTL regions on variations in panicle architecture. A detailed analysis of phenotypes versus genotypes was carried out between the two parental genomes within these regions in order to understand how O. glaberrima introgression events may lead to alterations in panicle traits. CONCLUSION: Our analysis led to the detection of genomic variations between O. sativa cv. Caiapó and O. glaberrima cv. MG12 in regions associated with enhanced panicle traits in specific CSSLs. These regions contain a number of key genes that regulate panicle development in O. sativa and their interspecific genomic variations may explain the phenotypic effects observed.


Asunto(s)
Oryza , Introgresión Genética , Sitios de Carácter Cuantitativo , Fenotipo , Genómica
3.
Plant Cell Physiol ; 63(11): 1654-1666, 2022 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-35876043

RESUMEN

Through the process of domestication, selection is targeted on a limited number of plant traits that are typically associated with yield. As an unintended consequence, domesticated plants often perform poorly compared to their wild progenitors for a multitude of traits that were not under selection during domestication, including abiotic and biotic stress tolerance. Over the past decade, advances in sequencing technology have allowed for the rigorous characterization of host-associated microbial communities, termed the microbiome. It is now clear that nearly every conceivable plant interaction with the environment is mediated by interactions with the microbiome. For this reason, plant-microbiome interactions are an area of great promise for plant breeding and crop improvement. Here, we review the literature to assess the potential impact that domestication has had on plant-microbiome interactions and the current understanding of the genetic basis of microbiome variation to inform plant breeding efforts. Overall, we find limited evidence that domestication impacts the diversity of microbiomes, but domestication is often associated with shifts in the abundance and composition of microbial communities, including taxa of known functional significance. Moreover, genome-wide association studies and mutant analysis have not revealed a consistent set of core candidate genes or genetic pathways that confer variation in microbiomes across systems. However, such studies do implicate a consistent role for plant immunity, root traits, root and leaf exudates and cell wall integrity as key traits that control microbiome colonization and assembly. Therefore, selection on these key traits may pose the most immediate promise for enhancing plant-microbiome interactions through breeding.


Asunto(s)
Domesticación , Microbiota , Estudio de Asociación del Genoma Completo , Bacterias/genética , Fitomejoramiento , Plantas/genética , Rizosfera
4.
Oncologist ; 27(6): 453-461, 2022 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-35373299

RESUMEN

BACKGROUND: ADXS31-142 is an attenuated Listeria monocytogenes-based immunotherapy targeting prostate-specific antigen (PSA), being evaluated as monotherapy and combined with pembrolizumab for metastatic castration-resistant prostate cancer (mCRPC). PATIENTS AND METHODS: The 2-part phase I/II KEYNOTE-046 study enrolled men with mCRPC who have progressed after 2 or fewer prior systemic treatment regimens in the metastatic setting. In Part A, intravenous ADXS31-142 monotherapy was given every 3 weeks (q3w) to 3 dose-escalation cohorts. In Part B, ADXS31-142 (1 × 109 colony-forming units) plus pembrolizumab (200 mg) was administered intravenously q3w for 3 doses with a fourth pembrolizumab dose 3 weeks later (12-week cycles) for up to 24 months or until progression/toxicity. Endpoints included safety, overall response rate, progression-free survival (PFS), overall survival (OS), and immunogenicity. RESULTS: Fifty patients received ADXS31-142 alone (n = 13) or with pembrolizumab (n = 37). Among the 37 RECIST-evaluable patients (n = 8 Part A; n = 29 Part B), there were no objective responses. Median PFS was 2.2 months (95% CI: 0.8-7.4) with monotherapy and 5.4 months (95% CI: 2.3-7.9) with the combination; median OS was 7.8 months (95% CI: 4.4-18.5) and 33.7 months (95% CI: 15.4-not evaluable), respectively. Promising OS benefit was observed in combination-treated patients who had received prior docetaxel (16.0 months, 95% CI: 6.4-34.6; n = 20) and those with visceral metastasis (16.4 months, 95% CI 4.0-not evaluable; n = 11). All patients had ≥1 treatment-related adverse event, mostly grade 1/2 manageable events. No additive toxicity was observed with combination treatment. CONCLUSIONS: Combining ADXS31-142 with pembrolizumab was safe and well tolerated. The observed OS in mCRPC warrants further testing of this combination. CLINICAL TRIAL REGISTRATION: NCT02325557.


Asunto(s)
Neoplasias de la Próstata Resistentes a la Castración , Anticuerpos Monoclonales Humanizados/farmacología , Anticuerpos Monoclonales Humanizados/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Docetaxel/uso terapéutico , Humanos , Inmunoterapia , Masculino , Neoplasias de la Próstata Resistentes a la Castración/tratamiento farmacológico , Neoplasias de la Próstata Resistentes a la Castración/patología
5.
Rev Gastroenterol Peru ; 42(2): 126-130, 2022.
Artículo en Español | MEDLINE | ID: mdl-36513359

RESUMEN

Acute pancreatitis is an inflammatory condition that is related to various etiologies. However, an infrequent one is acute infection by hepatotropic viruses. We present the case of a 33-year-old man who consulted the emergency department for abdominal pain and generalized jaundice. Serological studies reported acute infection by Hepatitis B Virus; The patient was managed with clinical and paraclinical monitoring of liver function tests together with supportive therapy with dextrose. The patient persisted with increasing abdominal pain and cholestasis, so they were considered differential. Magnetic resonance imaging of the upper abdomen showed acute non-biliary pancreatitis that was concluded secondary to the infectious process due to hepatitis B after ruling out other causes. The patient did not require changes in management with improvement in liver function tests, so he was discharged from hospital with favorable evolution in outpatient follow-up. Acute pancreatitis secondary to Hepatitis B Virus is a pathology that should be suspected and studied when the patient's clinical picture does not show improvement; Diagnosis is based on measurement of pancreatic enzyme levels.


Asunto(s)
Hepatitis B , Pancreatitis , Masculino , Humanos , Adulto , Pancreatitis/diagnóstico , Pancreatitis/etiología , Virus de la Hepatitis B , Enfermedad Aguda , Dolor Abdominal/etiología , Hepatitis B/complicaciones , Hepatitis B/diagnóstico
6.
J Neurosci ; 40(42): 8042-8054, 2020 10 14.
Artículo en Inglés | MEDLINE | ID: mdl-32928890

RESUMEN

Brain-derived neurotrophic factor (BDNF) is a key regulator of the morphology and connectivity of central neurons. We have previously shown that BDNF/TrkB signaling regulates the activity and mobility of the GTPases Rab5 and Rab11, which in turn determine the postendocytic sorting of signaling TrkB receptors. Moreover, decreased Rab5 or Rab11 activity inhibits BDNF-induced dendritic branching. Whether Rab5 or Rab11 activity is important for local events only or for regulating nuclear signaling and gene expression is unknown. Here, we investigated, in rat hippocampal neuronal cultures derived from embryos of unknown sex, whether BDNF-induced signaling cascades are altered when early and recycling endosomes are disrupted by the expression of dominant-negative mutants of Rab5 and Rab11. The activity of both Rab5 and Rab11 was required for sustained activity of Erk1/2 and nuclear CREB phosphorylation, and increased transcription of a BDNF-dependent program of gene expression containing CRE binding sites, which includes activity-regulated genes such as Arc, Dusp1, c-fos, Egr1, and Egr2, and growth and survival genes such as Atf3 and Gem Based on our results, we propose that early and recycling endosomes provide a platform for the integration of neurotrophic signaling from the plasma membrane to the nucleus in neurons, and that this mechanism is likely to regulate neuronal plasticity and survival.SIGNIFICANCE STATEMENT BDNF is a neurotrophic factor that regulates plastic changes in the brain, including dendritic growth. The cellular and molecular mechanisms underlying this process are not completely understood. Our results uncover the cellular requirements that central neurons possess to integrate the plasma membrane into nuclear signaling in neurons. Our results indicate that the endosomal pathway is required for the signaling cascade initiated by BDNF and its receptors at the plasma membrane to modulate BDNF-dependent gene expression and neuronal dendritic growth mediated by the CREB transcription factor. CREB is a key transcription factor regulating circuit development and learning and memory.


Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/farmacología , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/biosíntesis , Hipocampo/metabolismo , Neuronas/metabolismo , Transducción de Señal/fisiología , Proteínas de Unión al GTP rab/fisiología , Proteínas de Unión al GTP rab5/fisiología , Animales , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/genética , Dendritas/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/fisiología , Sistema de Señalización de MAP Quinasas/fisiología , Fosforilación , Cultivo Primario de Células , Ratas
7.
Paediatr Anaesth ; 31(10): 1097-1104, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34173295

RESUMEN

BACKGROUND: The Ramsay scale is the most widely used scale during pediatric procedures although it has not been formally validated. OBJECTIVE: To validate the Ramsay scale during invasive procedures under sedation in pediatrics. METHODS: A prospective analytic study was conducted in two hospitals. All patients ≥6 months that were undergoing invasive procedures under sedation were enrolled. All were recorded, and these videos were edited and randomized. 150 videos were scored by four observers (a pediatrician, a pediatric intensive care unit nurse, an anesthetist, and an operating room nurse). All videos were scored with the Ramsay scale and University of Michigan Sedation Scale. Observers were blinded to drug administration. Construct validity was measured through Wilcoxon test paired samples after administration of sedatives. Criterion validity, intra-observer reliability, and interobserver correlation were evaluated by comparing the scores of the scales using Spearman's correlation coefficient. Interobserver agreement was measured using the intraclass correlation coefficient. To assess test-retest reliability, 50 videos were randomly selected and reevaluated. RESULTS: Sixty-five patients were included. Construct validity was demonstrated through changes in the Ramsay scale scoring after administration of sedatives (p < .0001). Regarding criterion validity, the Ramsay scale had a high correlation with the UMSS (ρ = 0.621). Intra-observer agreement was ρ = 0.884. The Ramsay scale showed interobserver reliability with an intraclass correlation coefficient = 0.94 when comparing it with the University of Michigan Sedation Scale. Internal consistency was α = 0.91. Regarding applicability, in our study, it was applied in two hospitals in different areas by four professionals from distinct categories. CONCLUSIONS: The Ramsay scale is valid, reliable, and applicable to monitoring sedation for invasive procedures under deep sedation in pediatrics.


Asunto(s)
Sedación Profunda , Monitoreo Fisiológico/métodos , Pediatría , Niño , Sedación Consciente , Humanos , Hipnóticos y Sedantes , Estudios Prospectivos , Reproducibilidad de los Resultados
8.
Glia ; 68(6): 1213-1227, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-31876077

RESUMEN

Lactate/pyruvate transport between glial cells and neurons is thought to play an important role in how brain cells sustain the high-energy demand that neuronal activity requires. However, the in vivo mechanisms and characteristics that underlie the transport of monocarboxylates are poorly described. Here, we use Drosophila expressing genetically encoded FRET sensors to provide an ex vivo characterization of the transport of monocarboxylates in motor neurons and glial cells from the larval ventral nerve cord. We show that lactate/pyruvate transport in glial cells is coupled to protons and is more efficient than in neurons. Glial cells maintain higher levels of intracellular lactate generating a positive gradient toward neurons. Interestingly, during high neuronal activity, raised lactate in motor neurons is dependent on transfer from glial cells mediated in part by the previously described monocarboxylate transporter Chaski, providing support for in vivo glia-to-neuron lactate shuttling during neuronal activity.


Asunto(s)
Astrocitos/metabolismo , Encéfalo/metabolismo , Ácido Láctico/metabolismo , Neuroglía/metabolismo , Neuronas/metabolismo , Animales , Drosophila/metabolismo , Glucosa/metabolismo , Transportadores de Ácidos Monocarboxílicos/metabolismo , Ácido Pirúvico/metabolismo
9.
Genomics ; 111(6): 1794-1801, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-30529701

RESUMEN

Sugarcane is an economically important crop for both food and biofuel industries. Marker-assisted breeding in sugarcane is becoming a reality with the recent development and deployment of markers linked with disease resistance genes. Large linkage disequilibrium in sugarcane makes genome-wide association studies (GWAS) a better alternative to biparental mapping to identify markers associated with agronomic traits. GWAS was conducted on a Louisiana core collection to identify marker-trait associations (MTA) for 11 cane yield and sucrose traits using single nucleotide polymorphism (SNP) and insertion-deletion (Indel) markers. Significant (P < .05) MTAs were identified for all traits where the top ranked markers explained up to 15% of the total phenotypic variation. High correlations (0.732 to 0.999) were observed between sucrose traits and 56 markers were found consistent across multiple traits. These markers following validation in more diverse populations could be used in marker-assisted selection of clones in sugarcane breeding program in Louisiana and elsewhere.


Asunto(s)
Mapeo Cromosómico , Genoma de Planta , Desequilibrio de Ligamiento , Polimorfismo de Nucleótido Simple , Carácter Cuantitativo Heredable , Saccharum/genética , Marcadores Genéticos , Estudio de Asociación del Genoma Completo , Louisiana , Fitomejoramiento , Saccharum/metabolismo , Sacarosa/metabolismo
10.
Infection ; 47(3): 489-492, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30430399

RESUMEN

BACKGROUND: Listeria monocytogenes is a food-borne, facultative intracellular bacterium that causes severe diseases such as sepsis and meningoencephalitis in immunocompromised hosts. Because it stimulates robust T-lymphocyte-mediated responses, attenuated L. monocytogenes are candidate vaccine vectors for tumor immunotherapy. CASE: We report a case of bacteremia caused by vaccine strain L. monocytogenes (Axalimogene filolisbac) occurring 31 months after immunization against human papilloma virus (HPV) associated cervical cancer. CONCLUSION: Receipt of a L. monocytogenes-based vaccine is a novel risk factor for delayed L. monocytogenes bacteremia.


Asunto(s)
Bacteriemia/diagnóstico , Listeria monocytogenes/aislamiento & purificación , Listeriosis/diagnóstico , Infecciones por Papillomavirus/prevención & control , Neoplasias del Cuello Uterino/prevención & control , Bacteriemia/microbiología , Vacunas Bacterianas , Resultado Fatal , Femenino , Humanos , Inmunización , Listeriosis/microbiología , Persona de Mediana Edad , Oklahoma , Infecciones por Papillomavirus/virología , Factores de Tiempo , Neoplasias del Cuello Uterino/virología
11.
Int Braz J Urol ; 45(5): 1064-1070, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31184456

RESUMEN

The anti-Müllerian hormone triggers the regression of uterus and fallopian tubes in male embryos; if there are problems in the synthesis or action of this protein, Müllerian structures persist in an otherwise phenotypic male. The most frequent clinical presentation of Persistent Mullerian Duct syndrome is cryptorchidism and inguinal hernia. The few cases reported in adults are incidental findings or inguinal hernias. However, we present an adult male with history of bilateral cryptorchidism with unsuccessful orchidopexy, who presents with a large abdominal mass with the finding of a seminomatous tumor and persistence of Müllerian structures, in whom the variant c.916delC (p.Leu306Cysfs*29) in the AMHR2 gene not previously reported was documented.


Asunto(s)
Trastorno del Desarrollo Sexual 46,XY/genética , Homocigoto , Mutación , Fenotipo , Adulto , Hormona Antimülleriana/genética , Colombia , Criptorquidismo/genética , Criptorquidismo/cirugía , Análisis Citogenético , Trastorno del Desarrollo Sexual 46,XY/cirugía , Humanos , Masculino , Conductos Paramesonéfricos/anomalías , Conductos Paramesonéfricos/cirugía , Seminoma/genética , Seminoma/cirugía , Síndrome , Neoplasias Testiculares/genética , Neoplasias Testiculares/cirugía
12.
Ecol Lett ; 21(3): 345-355, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29314479

RESUMEN

Human activities often replace native forests with warmer, modified habitats that represent novel thermal environments for biodiversity. Reducing biodiversity loss hinges upon identifying which species are most sensitive to the environmental conditions that result from habitat modification. Drawing on case studies and a meta-analysis, we examined whether observed and modelled thermal traits, including heat tolerances, variation in body temperatures, and evaporative water loss, explained variation in sensitivity of ectotherms to habitat modification. Low heat tolerances of lizards and amphibians and high evaporative water loss of amphibians were associated with increased sensitivity to habitat modification, often explaining more variation than non-thermal traits. Heat tolerances alone explained 24-66% (mean = 38%) of the variation in species responses, and these trends were largely consistent across geographic locations and spatial scales. As habitat modification alters local microclimates, the thermal biology of species will likely play a key role in the reassembly of terrestrial communities.


Asunto(s)
Anfibios , Biodiversidad , Ecosistema , Reptiles , Animales , Bosques , Humanos , Metaanálisis como Asunto , Microclima
13.
Ann Diagn Pathol ; 32: 28-34, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29414394

RESUMEN

Acute reoviral infection has been extensively studied given the virus's propensity to target malignant cells and activate caspase-3 mediated apoptosis. Reovirus infection of malignant N1E-115 mouse neuroblastoma cells led to significant increased expression of importin-ß and exportin-5 mRNAs (qRTPCR) and proteins (immunohistochemistry) which was partially blocked by small interfering LNA oligomers directed against the reoviral genome. Co-expression analysis showed that the N1E-115 cells that contained reoviral capsid protein had accumulated importin-ß and exportin-5, as well as activated caspase 3. Reoviral oncolysis using a syngeneic mouse model of multiple myeloma similarly induced a significant increase in importin-ß and exportin-5 proteins that were co-expressed with reoviral capsid protein and caspase-3. Apoptotic proteins (BAD, BIM, PUMA, NOXA, BAK, BAX) were increased with infection and co-localized with reoviral capsid protein. Surprisingly the anti-apoptotic MCL1 and bcl2 were also increased and co-localized with the capsid protein suggesting that it was the balance of pro-apoptotic molecules that correlated with activation of caspase-3. In summary, productive reoviral infection is strongly correlated with elevated importin-ß and exportin-5 levels which may serve as biomarkers of the disease in clinical specimens.


Asunto(s)
Biomarcadores/metabolismo , Carioferinas/metabolismo , Mieloma Múltiple/metabolismo , Viroterapia Oncolítica/métodos , Infecciones por Reoviridae/metabolismo , beta Carioferinas/metabolismo , Animales , Línea Celular Tumoral , Ratones , Ratones Endogámicos C57BL , Mieloma Múltiple/virología , Virus Oncolíticos
15.
BMC Bioinformatics ; 16: 290, 2015 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-26370412

RESUMEN

BACKGROUND: T cell epitope prediction tools and associated vaccine design algorithms have accelerated the development of vaccines for humans. Predictive tools for swine and other food animals are not as well developed, primarily because the data required to develop the tools are lacking. Here, we overcome a lack of T cell epitope data to construct swine epitope predictors by systematically leveraging available human information. Applying the "pocket profile method", we use sequence and structural similarities in the binding pockets of human and swine major histocompatibility complex proteins to infer Swine Leukocyte Antigen (SLA) peptide binding preferences. We developed epitope-prediction matrices (PigMatrices), for three SLA class I alleles (SLA-1*0401, 2*0401 and 3*0401) and one class II allele (SLA-DRB1*0201), based on the binding preferences of the best-matched Human Leukocyte Antigen (HLA) pocket for each SLA pocket. The contact residues involved in the binding pockets were defined for class I based on crystal structures of either SLA (SLA-specific contacts, Ssc) or HLA supertype alleles (HLA contacts, Hc); for class II, only Hc was possible. Different substitution matrices were evaluated (PAM and BLOSUM) for scoring pocket similarity and identifying the best human match. The accuracy of the PigMatrices was compared to available online swine epitope prediction tools such as PickPocket and NetMHCpan. RESULTS: PigMatrices that used Ssc to define the pocket sequences and PAM30 to score pocket similarity demonstrated the best predictive performance and were able to accurately separate binders from random peptides. For SLA-1*0401 and 2*0401, PigMatrix achieved area under the receiver operating characteristic curves (AUC) of 0.78 and 0.73, respectively, which were equivalent or better than PickPocket (0.76 and 0.54) and NetMHCpan version 2.4 (0.41 and 0.51) and version 2.8 (0.72 and 0.71). In addition, we developed the first predictive SLA class II matrix, obtaining an AUC of 0.73 for existing SLA-DRB1*0201 epitopes. Notably, PigMatrix achieved this level of predictive power without training on SLA binding data. CONCLUSION: Overall, the pocket profile method combined with binding preferences from HLA binding data shows significant promise for developing T cell epitope prediction tools for pigs. When combined with existing vaccine design algorithms, PigMatrix will be useful for developing genome-derived vaccines for a range of pig pathogens for which no effective vaccines currently exist (e.g. porcine reproductive and respiratory syndrome, influenza and porcine epidemic diarrhea).


Asunto(s)
Algoritmos , Biología Computacional/métodos , Mapeo Epitopo/métodos , Epítopos de Linfocito T/inmunología , Antígenos de Histocompatibilidad Clase II/inmunología , Antígenos de Histocompatibilidad Clase I/inmunología , Modelos Teóricos , Alelos , Animales , Dominio Catalítico , Epítopos de Linfocito T/química , Humanos , Simulación del Acoplamiento Molecular , Fragmentos de Péptidos/inmunología , Fragmentos de Péptidos/metabolismo , Unión Proteica , Conformación Proteica , Estructura Terciaria de Proteína , Curva ROC , Porcinos , Vacunas/inmunología
16.
J Hepatol ; 62(1): 48-55, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25157982

RESUMEN

BACKGROUND & AIMS: Spontaneous resolution of hepatitis C virus (HCV) infection depends upon a broad T cell response to multiple viral epitopes. However, most patients fail to clear infections spontaneously and develop chronic disease. The elevated number and function of CD3(+)CD4(+)CD25(+)FoxP3(+) regulatory T cells (T(reg)) in HCV-infected patients suggest a role of Treg cells in impaired viral clearance. The factors contributing to increased Treg cell activity in chronic hepatitis C cases remain to be delineated. METHODS: Immunoinformatics tools were used to predict promiscuous, highly-conserved HLA-DRB1-restricted immunogenic consensus sequences (ICS), each composed of multiple T cell epitopes. These sequences were synthesized and added to cultures of peripheral blood mononuclear cells (PBMCs), derived from patients who resolved HCV infection spontaneously, patients with persistent infection, and non-infected individuals. The cells were collected and following 5days incubation, quantified and characterized by flow cytometry. RESULTS: One immunogenic consensus sequence (ICS), HCV_G1_p7_794, induced a marked increase in Treg cells in PBMC cultures derived from infected patients, but not in patients who spontaneously cleared HCV or in non-infected individuals. An analogous human peptide (p7_794), on the other hand, induced a significant increase in Treg cells among PBMCs derived from both HCV-infected and non-infected individuals. JanusMatrix analyses determined that HCV_G1_p7_794 is comprised of Treg cell epitopes that exhibit extensive cross-reactivity with the human proteome. CONCLUSIONS: A virus-encoded peptide (HCV_G1_p7_794) with extensive human homology activates cross-reactive CD3(+)CD4(+)CD25(+)FoxP3(+) natural Treg cells, which potentially contributes to immunosuppression and to the development of chronic hepatitis C.


Asunto(s)
Epítopos de Linfocito T/inmunología , Hepacivirus/inmunología , Hepatitis C Crónica/inmunología , Tolerancia Inmunológica , Linfocitos T Reguladores/inmunología , Adulto , Femenino , Citometría de Flujo , Hepatitis C Crónica/metabolismo , Hepatitis C Crónica/virología , Humanos , Masculino , Adulto Joven
17.
JAMA ; 314(3): 237-46, 2015 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-26197184

RESUMEN

IMPORTANCE: Human infections with the avian influenza A(H7N9) virus were first reported in China in 2013 and continue to occur. Hemagglutinin H7 administered alone is a poor immunogen necessitating evaluation of adjuvanted H7N9 vaccines. OBJECTIVE: To evaluate the immunogenicity and safety of an inactivated H7N9 vaccine with and without AS03 adjuvant, as well as mixed vaccine schedules that included sequential administration of AS03- and MF59-containing formulations and of adjuvanted and unadjuvanted formulations. DESIGN, SETTING, AND PARTICIPANTS: Double-blind, phase 2 trial at 5 US sites enrolled 980 adults aged 19 through 64 years from September 2013 through November 2013; safety follow-up was completed in January 2015. INTERVENTIONS: The H7N9 vaccine was given on days 0 and 21 at nominal doses of 3.75 µg, 7.5 µg, 15 µg, and 45 µg of hemagglutinin with or without AS03 or MF59 adjuvant mixed on site. MAIN OUTCOMES AND MEASURES: Proportions achieving a hemagglutination inhibition antibody (HIA) titer of 40 or higher at 21 days after the second vaccination; vaccine-related serious adverse events through 12 months after the first vaccination; and solicited signs and symptoms after vaccination through day 7. RESULTS: Two doses of vaccine were required to induce detectable antibody titers in most participants. After 2 doses of an H7N9 formulation containing 15 µg of hemagglutinin given without adjuvant, with AS03 adjuvant, or with MF59 adjuvant, the proportion achieving an HIA titer of 40 or higher was 2% (95% CI, 0%-7%) without adjuvant (n = 94), 84% (95% CI, 76%-91%) with AS03 adjuvant (n = 96), and 57% (95% CI, 47%-68%) with MF59 adjuvant (n = 92) (P < .001 for comparison of the AS03 and MF59 schedules). The 2 schedules alternating AS03-and MF59-adjuvanted formulations led to lower geometric mean titers (GMTs) of (41.5 [95% CI, 31.7-54.4]; n = 92) and (58.6 [95% CI, 44.3-77.6]; n = 96) than the group induced by 2 AS03-adjuvanted formulations (n = 96) (103.4 [95% CI, 78.7-135.9]; P < .001) but higher GMTs than 2 doses of MF59-adjuvanted formulation (n = 94) (29.0 [95% CI, 22.4-37.6]; P < .001). CONCLUSIONS AND RELEVANCE: The AS03 and MF59 adjuvants augmented the immune responses to 2 doses of an inactivated H7N9 influenza vaccine, with AS03-adjuvanted formulations inducing the highest titers. This study of 2 adjuvants used in influenza vaccine formulations with adjuvant mixed on site provides immunogenicity information that may be informative to influenza pandemic preparedness programs. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01942265.


Asunto(s)
Adyuvantes Inmunológicos/administración & dosificación , Subtipo H7N9 del Virus de la Influenza A , Vacunas contra la Influenza/administración & dosificación , Gripe Humana/inmunología , Adulto , Factores de Edad , Anticuerpos Antivirales/sangre , Método Doble Ciego , Combinación de Medicamentos , Femenino , Pruebas de Inhibición de Hemaglutinación , Hemaglutinación por Virus/inmunología , Humanos , Vacunas contra la Influenza/efectos adversos , Vacunas contra la Influenza/inmunología , Gripe Humana/prevención & control , Masculino , Persona de Mediana Edad , Polisorbatos/administración & dosificación , Escualeno/administración & dosificación , alfa-Tocoferol/administración & dosificación
18.
BMC Bioinformatics ; 15 Suppl 4: S1, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25104221

RESUMEN

BACKGROUND: Immune recognition of foreign proteins by T cells hinges on the formation of a ternary complex sandwiching a constituent peptide of the protein between a major histocompatibility complex (MHC) molecule and a T cell receptor (TCR). Viruses have evolved means of "camouflaging" themselves, avoiding immune recognition by reducing the MHC and/or TCR binding of their constituent peptides. Computer-driven T cell epitope mapping tools have been used to evaluate the degree to which particular viruses have used this means of avoiding immune response, but most such analyses focus on MHC-facing 'agretopes'. Here we set out a new means of evaluating the TCR faces of viral peptides in addition to their agretopes, integrating evaluations of both sides of the ternary complex in a single analysis. METHODS: This paper develops what we call the Janus Immunogenicity Score (JIS), bringing together a well-established method for predicting MHC binding, with a novel assessment of the potential for TCR binding based on similarity with self. Intuitively, both good MHC binding and poor self-similarity are required for high immunogenicity (i.e., a robust T effector response). RESULTS: Focusing on the class II antigen-processing pathway, we show that the JIS of T effector epitopes and null or regulatory epitopes deposited in a large database of epitopes (Immune Epitope Database) are significantly different. We then show that different types of viruses display significantly different patterns of scores over their constituent peptides, with viruses causing chronic infection (Epstein-Barr and cytomegalovirus) strongly shifted to lower scores relative to those causing acute infection (Ebola and Marburg). Similarly we find distinct patterns among influenza proteins in H1N1 (a strain against which human populations rapidly developed immunity) and H5N1 and H7N9 (highly pathogenic avian flu strains, with significantly greater case mortality rates). CONCLUSION: The Janus Immunogenicity Score, which integrates MHC binding and TCR cross-reactivity, provides a new tool for studying immunogenicity of pathogens and may improve the selection and optimization of antigenic elements for vaccine design.


Asunto(s)
Biología Computacional/métodos , Epítopos de Linfocito T/inmunología , Antígenos de Histocompatibilidad Clase II/inmunología , Complejo Mayor de Histocompatibilidad , Receptores de Antígenos de Linfocitos T/inmunología , Vacunas Virales/inmunología , Virus/inmunología , Animales , Reacciones Cruzadas , Bases de Datos Factuales , Humanos , Subtipo H1N1 del Virus de la Influenza A/inmunología , Subtipo H5N1 del Virus de la Influenza A/inmunología , Gripe Humana/inmunología , Modelos Biológicos , Modelos Moleculares , Infecciones por Orthomyxoviridae/inmunología , Linfocitos T/inmunología , Linfocitos T/virología , Proteínas Virales/inmunología , Vacunas Virales/química , Virosis/inmunología
19.
Brief Bioinform ; 13(3): 329-36, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-21930656

RESUMEN

In recent years, numerous biocomputational tools have been designed to extract functional and evolutionary information from multiple sequence alignments (MSAs) of proteins and genes. Most biologists working actively on the characterization of proteins from a single or family perspective use the MSA analysis to retrieve valuable information about amino acid conservation and the functional role of residues in query protein(s). In MSAs, adjustment of alignment parameters is a key point to improve the quality of MSA output. However, this issue is frequently underestimated and/or misunderstood by scientists and there is no in-depth knowledge available in this field. This brief review focuses on biocomputational approaches complementary to MSA to help distinguish functional residues in protein families. These additional analyses involve issues ranging from phylogenetic to statistical, which address the detection of amino acids pivotal for protein function at any level. In recent years, a large number of tools has been designed for this very purpose. Using some of these relevant, useful tools, we have designed a practical pipeline to perform in silico studies with a view to improving the characterization of family proteins and their functional residues. This review-guide aims to present biologists a set of specially designed tools to study proteins. These tools are user-friendly as they use web servers or easy-to-handle applications. Such criteria are essential for this review as most of the biologists (experimentalists) working in this field are unfamiliar with these biocomputational analysis approaches.


Asunto(s)
Biología Computacional/métodos , Proteínas/química , Aminoácidos/genética , Bases de Datos de Proteínas , Filogenia , Alineación de Secuencia , Análisis de Secuencia de Proteína
20.
Biotechnol Bioeng ; 111(11): 2170-82, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24888712

RESUMEN

Despite high quality standards and continual process improvements in manufacturing, host cell protein (HCP) process impurities remain a substantial risk for biological products. Even at low levels, residual HCPs can induce a detrimental immune response compromising the safety and efficacy of a biologic. Consequently, advanced-stage clinical trials have been cancelled due to the identification of antibodies against HCPs. To enable earlier and rapid assessment of the risks in Chinese Hamster Ovary (CHO)-based protein production of residual CHO protein impurities (CHOPs), we have developed a web tool called CHOPPI, for CHO Protein Predicted Immunogenicity. CHOPPI integrates information regarding the possible presence of CHOPs (expression and secretion) with characterizations of their immunogenicity (T cell epitope count and density, and relative conservation with human counterparts). CHOPPI can generate a report for a specified CHO protein (e.g., identified from proteomics or immunoassays) or characterize an entire specified subset of the CHO genome (e.g., filtered based on confidence in transcription and similarity to human proteins). The ability to analyze potential CHOPs at a genomic scale provides a baseline to evaluate relative risk. We show here that CHOPPI can identify clear differences in immunogenicity risk among previously validated CHOPs, as well as identify additional "risky" CHO proteins that may be expressed during production and induce a detrimental immune response upon delivery. We conclude that CHOPPI is a powerful tool that provides a valuable computational complement to existing experimental approaches for CHOP risk assessment and can focus experimental efforts in the most important directions. Biotechnol. Bioeng. 2014;111: 2170-2182. © 2014 Wiley Periodicals, Inc.


Asunto(s)
Productos Biológicos/inmunología , Productos Biológicos/metabolismo , Biología Computacional/métodos , Contaminación de Medicamentos , Animales , Células CHO/metabolismo , Cricetulus , Internet , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/metabolismo
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