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1.
Nature ; 596(7872): 417-422, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34192737

RESUMEN

Although two-dose mRNA vaccination provides excellent protection against SARS-CoV-2, there is little information about vaccine efficacy against variants of concern (VOC) in individuals above eighty years of age1. Here we analysed immune responses following vaccination with the BNT162b2 mRNA vaccine2 in elderly participants and younger healthcare workers. Serum neutralization and levels of binding IgG or IgA after the first vaccine dose were lower in older individuals, with a marked drop in participants over eighty years old. Sera from participants above eighty showed lower neutralization potency against the B.1.1.7 (Alpha), B.1.351 (Beta) and P.1. (Gamma) VOC than against the wild-type virus and were more likely to lack any neutralization against VOC following the first dose. However, following the second dose, neutralization against VOC was detectable regardless of age. The frequency of SARS-CoV-2 spike-specific memory B cells was higher in elderly responders (whose serum showed neutralization activity) than in non-responders after the first dose. Elderly participants showed a clear reduction in somatic hypermutation of class-switched cells. The production of interferon-γ and interleukin-2 by SARS-CoV-2 spike-specific T cells was lower in older participants, and both cytokines were secreted primarily by CD4 T cells. We conclude that the elderly are a high-risk population and that specific measures to boost vaccine responses in this population are warranted, particularly where variants of concern are circulating.


Asunto(s)
Envejecimiento/inmunología , Vacunas contra la COVID-19/inmunología , Inmunidad , SARS-CoV-2/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento/sangre , Anticuerpos Neutralizantes/sangre , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Autoanticuerpos/inmunología , Linfocitos B/citología , Linfocitos B/inmunología , Linfocitos B/metabolismo , Vacuna BNT162 , Vacunas contra la COVID-19/administración & dosificación , Femenino , Personal de Salud , Humanos , Inmunidad/genética , Inmunización Secundaria , Inmunoglobulina A/inmunología , Cambio de Clase de Inmunoglobulina , Inmunoglobulina G/genética , Inmunoglobulina G/inmunología , Memoria Inmunológica/inmunología , Inflamación/sangre , Inflamación/inmunología , Interferón gamma/inmunología , Interleucina-2/inmunología , Masculino , Persona de Mediana Edad , Hipermutación Somática de Inmunoglobulina , Glicoproteína de la Espiga del Coronavirus/inmunología , Linfocitos T/inmunología , Vacunación , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/inmunología , Vacunas de ARNm
2.
Nature ; 592(7853): 277-282, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33545711

RESUMEN

The spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical for virus infection through the engagement of the human ACE2 protein1 and is a major antibody target. Here we show that chronic infection with SARS-CoV-2 leads to viral evolution and reduced sensitivity to neutralizing antibodies in an immunosuppressed individual treated with convalescent plasma, by generating whole-genome ultra-deep sequences for 23 time points that span 101 days and using in vitro techniques to characterize the mutations revealed by sequencing. There was little change in the overall structure of the viral population after two courses of remdesivir during the first 57 days. However, after convalescent plasma therapy, we observed large, dynamic shifts in the viral population, with the emergence of a dominant viral strain that contained a substitution (D796H) in the S2 subunit and a deletion (ΔH69/ΔV70) in the S1 N-terminal domain of the spike protein. As passively transferred serum antibodies diminished, viruses with the escape genotype were reduced in frequency, before returning during a final, unsuccessful course of convalescent plasma treatment. In vitro, the spike double mutant bearing both ΔH69/ΔV70 and D796H conferred modestly decreased sensitivity to convalescent plasma, while maintaining infectivity levels that were similar to the wild-type virus.The spike substitution mutant D796H appeared to be the main contributor to the decreased susceptibility to neutralizing antibodies, but this mutation resulted in an infectivity defect. The spike deletion mutant ΔH69/ΔV70 had a twofold higher level of infectivity than wild-type SARS-CoV-2, possibly compensating for the reduced infectivity of the D796H mutation. These data reveal strong selection on SARS-CoV-2 during convalescent plasma therapy, which is associated with the emergence of viral variants that show evidence of reduced susceptibility to neutralizing antibodies in immunosuppressed individuals.


Asunto(s)
Tratamiento Farmacológico de COVID-19 , COVID-19/terapia , COVID-19/virología , Evolución Molecular , Mutagénesis/efectos de los fármacos , SARS-CoV-2/efectos de los fármacos , SARS-CoV-2/genética , Adenosina Monofosfato/análogos & derivados , Adenosina Monofosfato/farmacología , Adenosina Monofosfato/uso terapéutico , Anciano , Alanina/análogos & derivados , Alanina/farmacología , Alanina/uso terapéutico , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , COVID-19/inmunología , Enfermedad Crónica , Genoma Viral/efectos de los fármacos , Genoma Viral/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Evasión Inmune/efectos de los fármacos , Evasión Inmune/genética , Evasión Inmune/inmunología , Tolerancia Inmunológica/efectos de los fármacos , Tolerancia Inmunológica/inmunología , Inmunización Pasiva , Terapia de Inmunosupresión , Masculino , Proteínas Mutantes/química , Proteínas Mutantes/genética , Proteínas Mutantes/inmunología , Mutación , Filogenia , SARS-CoV-2/inmunología , SARS-CoV-2/metabolismo , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Factores de Tiempo , Carga Viral/efectos de los fármacos , Esparcimiento de Virus , Sueroterapia para COVID-19
3.
Nature ; 593(7857): 136-141, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33706364

RESUMEN

Transmission of SARS-CoV-2 is uncontrolled in many parts of the world; control is compounded in some areas by the higher transmission potential of the B.1.1.7 variant1, which has now been reported in 94 countries. It is unclear whether the response of the virus to vaccines against SARS-CoV-2 on the basis of the prototypic strain will be affected by the mutations found in B.1.1.7. Here we assess the immune responses of individuals after vaccination with the mRNA-based vaccine BNT162b22. We measured neutralizing antibody responses after the first and second immunizations using pseudoviruses that expressed the wild-type spike protein or a mutated spike protein that contained the eight amino acid changes found in the B.1.1.7 variant. The sera from individuals who received the vaccine exhibited a broad range of neutralizing titres against the wild-type pseudoviruses that were modestly reduced against the B.1.1.7 variant. This reduction was also evident in sera from some patients who had recovered from COVID-19. Decreased neutralization of the B.1.1.7 variant was also observed for monoclonal antibodies that target the N-terminal domain (9 out of 10) and the receptor-binding motif (5 out of 31), but not for monoclonal antibodies that recognize the receptor-binding domain that bind outside the receptor-binding motif. Introduction of the mutation that encodes the E484K substitution in the B.1.1.7 background to reflect a newly emerged variant of concern (VOC 202102/02) led to a more-substantial loss of neutralizing activity by vaccine-elicited antibodies and monoclonal antibodies (19 out of 31) compared with the loss of neutralizing activity conferred by the mutations in B.1.1.7 alone. The emergence of the E484K substitution in a B.1.1.7 background represents a threat to the efficacy of the BNT162b2 vaccine.


Asunto(s)
Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Vacunas contra la COVID-19/inmunología , COVID-19/inmunología , COVID-19/terapia , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Vacunas Sintéticas/inmunología , Anciano , Anciano de 80 o más Años , Enzima Convertidora de Angiotensina 2/metabolismo , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/aislamiento & purificación , Anticuerpos Neutralizantes/aislamiento & purificación , Anticuerpos Antivirales/aislamiento & purificación , COVID-19/metabolismo , COVID-19/virología , Femenino , Células HEK293 , Humanos , Evasión Inmune/genética , Evasión Inmune/inmunología , Inmunización Pasiva , Masculino , Persona de Mediana Edad , Modelos Moleculares , Mutación , Pruebas de Neutralización , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/metabolismo , Vacunas Sintéticas/administración & dosificación , Sueroterapia para COVID-19 , Vacunas de ARNm
4.
Brain ; 145(11): 4097-4107, 2022 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-36065116

RESUMEN

COVID-19 is associated with neurological complications including stroke, delirium and encephalitis. Furthermore, a post-viral syndrome dominated by neuropsychiatric symptoms is common, and is seemingly unrelated to COVID-19 severity. The true frequency and underlying mechanisms of neurological injury are unknown, but exaggerated host inflammatory responses appear to be a key driver of COVID-19 severity. We investigated the dynamics of, and relationship between, serum markers of brain injury [neurofilament light (NfL), glial fibrillary acidic protein (GFAP) and total tau] and markers of dysregulated host response (autoantibody production and cytokine profiles) in 175 patients admitted with COVID-19 and 45 patients with influenza. During hospitalization, sera from patients with COVID-19 demonstrated elevations of NfL and GFAP in a severity-dependent manner, with evidence of ongoing active brain injury at follow-up 4 months later. These biomarkers were associated with elevations of pro-inflammatory cytokines and the presence of autoantibodies to a large number of different antigens. Autoantibodies were commonly seen against lung surfactant proteins but also brain proteins such as myelin associated glycoprotein. Commensurate findings were seen in the influenza cohort. A distinct process characterized by elevation of serum total tau was seen in patients at follow-up, which appeared to be independent of initial disease severity and was not associated with dysregulated immune responses unlike NfL and GFAP. These results demonstrate that brain injury is a common consequence of both COVID-19 and influenza, and is therefore likely to be a feature of severe viral infection more broadly. The brain injury occurs in the context of dysregulation of both innate and adaptive immune responses, with no single pathogenic mechanism clearly responsible.


Asunto(s)
Lesiones Encefálicas , COVID-19 , Gripe Humana , Humanos , Proteínas de Neurofilamentos , COVID-19/complicaciones , Biomarcadores , Autoanticuerpos , Inmunidad
7.
Proc Natl Acad Sci U S A ; 117(49): 31301-31308, 2020 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-33229589

RESUMEN

The function of the nucleus depends on the integrity of the nuclear lamina, an intermediate filament network associated with the linker of nucleoskeleton and cytoskeleton (LINC) complex. The LINC complex spans the nuclear envelope and mediates nuclear mechanotransduction, the process by which mechanical signals and forces are transmitted across the nuclear envelope. In turn, the AAA+ ATPase torsinA is thought to regulate force transmission from the cytoskeleton to the nucleus. In humans, mutations affecting nuclear envelope-associated proteins cause laminopathies, including progeria, myopathy, and dystonia, though the extent to which endogenous mechanical stresses contribute to these pathologies is unclear. Here, we use the Caenorhabditis elegans germline as a model to investigate mechanisms that maintain nuclear integrity as germ cell nuclei progress through meiotic development and migrate for gametogenesis-processes that require LINC complex function. We report that decreasing the function of the C. elegans torsinA homolog, OOC-5, rescues the sterility and premature aging caused by a null mutation in the single worm lamin homolog. We show that decreasing OOC-5/torsinA activity prevents nuclear collapse in lamin mutants by disrupting the function of the LINC complex. At a mechanistic level, OOC-5/torsinA promotes the assembly or maintenance of the lamin-associated LINC complex and this activity is also important for interphase nuclear pore complex insertion into growing germline nuclei. These results demonstrate that LINC complex-transmitted forces damage nuclei with a compromised nuclear lamina. Thus, the torsinA-LINC complex nexus might comprise a therapeutic target for certain laminopathies by preventing damage from endogenous cellular forces.


Asunto(s)
Caenorhabditis elegans/metabolismo , Núcleo Celular/metabolismo , Laminopatías/patología , Mecanotransducción Celular , Animales , Proteínas de Caenorhabditis elegans/metabolismo , Interfase , Longevidad , Meiosis , Modelos Biológicos , Mutación/genética , Poro Nuclear/metabolismo , Profase
8.
J Infect Dis ; 225(10): 1822-1831, 2022 05 16.
Artículo en Inglés | MEDLINE | ID: mdl-34850023

RESUMEN

BACKGROUND: Immune defects in chronic pulmonary aspergillosis (CPA) are poorly characterized. We compared peripheral blood cytokine profiles in patients with CPA versus healthy controls and explored the relationship with disease severity. METHODS: Interferon-gamma (IFNγ), interleukin (IL)-17, tumor necrosis factor-α, IL-6, IL-12, and IL-10 were measured after in vitro stimulation of whole blood with lipopolysaccharide (LPS), phytohemagglutinin, ß-glucan, zymosan (ZYM), IL-12 or IL-18, and combinations. Clinical parameters and mortality were correlated with cytokine production. RESULTS: Cytokine profiles were evaluated in 133 patients (57.1% male, mean age 61 years). In comparison to controls, patients with CPA had significantly reduced production of IFNγ in response to stimulation with ß-glucan + IL-12 (312 vs 988 pg/mL), LPS + IL-12 (252 vs 1033 pg/mL), ZYM + IL-12 (996 vs 2347 pg/mL), and IL-18 + IL-12 (7193 vs 12 330 pg/mL). Age >60 (hazard ratio [HR], 1.71; 95% confidence interval [CI], 1.00-2.91; P = .05) and chronic obstructive pulmonary disease (HR, 1.69; 95% CI, 1.03-2.78; P = .039) were associated with worse survival, whereas high IFNγ production in response to beta-glucan + IL-12 stimulation (HR, 0.48; 95% CI, .25-0.92; P = .026) was associated with reduced mortality. CONCLUSIONS: Patients with CPA show impaired IFNγ production in peripheral blood in response to stimuli. Defective IFNγ production ability correlates with worse outcomes. Immunotherapy with IFNγ could be beneficial for patients showing impaired IFNγ production in CPA.


Asunto(s)
Interferón gamma , Aspergilosis Pulmonar , Citocinas , Femenino , Humanos , Interleucina-12 , Interleucina-18 , Lipopolisacáridos , Masculino , Persona de Mediana Edad , Factor de Necrosis Tumoral alfa , beta-Glucanos
9.
Gac Med Mex ; 159(2): 154-160, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37094237

RESUMEN

Anti-cytokine autoantibodies (ACAA) have been reported to be an important cause of secondary immunodeficiencies. High titers of neutralizing autoantibodies may cause susceptibility to different life-threatening infectious diseases. For example, neutralizing autoantibodies against IFNg have been reported to be correlated with susceptibility to mycobacterial infections and intracellular fungal pathogens. Autoantibodies against IL-6 were detected in patients with subcutaneous abscesses and recurrent staphylococcal cellulitis; on the other hand, patients with cryptococcosis, nocardiosis, and pulmonary alveolar proteinosis were positive for autoantibodies to GM-CSF. A relationship has also been established between autoantibodies against IL-17 and IL-22 and chronic mucosal Candida infections, which have been identified in patients with APECED or thymoma. Autoantibodies against type-I IFN have been recently reported during the onset of acute COVID-19. These ACAAs resemble genetic defects in cytokines or their signaling pathways. Therefore, they may be considered to be primary immunodeficiencies phenocopies. Consequently, the detection of ACAA could be important in the diagnosis of patients, particularly in the case of late-onset diseases, in order to decide appropriate treatments. This review presents an overview of current understanding of ACAA-associated secondary immunodeficiencies.


Los autoanticuerpos anticitocinas (ACAA) han sido reportados como causa importante de inmunodeficiencias secundarias. Altos títulos de autoanticuerpos neutralizantes pueden causar susceptibilidad a diferentes enfermedades infecciosas potencialmente mortales. Por ejemplo, se ha informado que autoanticuerpos neutralizantes contra IFNg se correlacionan con susceptibilidad a infecciones micobacterianas y patógenos fúngicos intracelulares. Autoanticuerpos contra IL-6 se detectaron en pacientes con abscesos subcutáneos y celulitis estafilocócica recurrente; asimismo, pacientes con criptococosis, nocardiosis y proteinosis alveolar pulmonar fueron positivos a autoanticuerpos contra GM-CSF. También se ha establecido una relación entre los autoanticuerpos contra IL-17 e IL-22 y las infecciones crónicas por Candida en mucosas, que se han identificado en pacientes con poliendocrinopatía autoinmune tipo 1 o timoma. Recientemente se han reportado autoanticuerpos contra interferón tipo I durante el inicio de COVID-19 aguda. Estos ACAA se asemejan a defectos genéticos en citocinas o en sus rutas de señalización. Por ello, pueden considerarse fenocopias de inmunodeficiencias primarias. De esta forma, la detección de ACAA podría ser importante en el diagnóstico, particularmente en pacientes con enfermedades de aparición tardía, para decidir los tratamientos apropiados. Esta revisión presenta una descripción general de la comprensión actual de las inmunodeficiencias secundarias asociadas a ACAA.


Asunto(s)
COVID-19 , Criptococosis , Síndromes de Inmunodeficiencia , Humanos , Citocinas , Autoanticuerpos
10.
J Mater Cycles Waste Manag ; 25(2): 1153-1167, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36747511

RESUMEN

The aim of this study was to analyze the efficiency of a system of treatment of organic swine waste as a management tool in the transformation of organic waste into products of value in the swine industry. The residues from the pig farm and the products obtained (compost, biol and biogas) were quantified and characterized, as were the energy used within the process and the distribution of the products. The negative impacts on the soil and adjacent river, as well as the efficiency of the compost as fertilizers and biol in grass and corn crops, were evaluated. The subsystems were: S1-slurry separation, S2-anaerobic digestion, S3-composting solid fraction of slurry, and S4-composting of dead tissues. S2 was not efficient in obtaining biol, with COD and TSS required. The process requires 31.1 kW/d of electrical energy and 3.22 L/d of diesel. The biogas (35,486.0 m3/d) is used for cooking food and heating houses, whilst the compost (82 kg/d) and biol (7.72 m3/d) replace inorganic fertilizers in crops. The system was adequate for the transformation of 38,109.0 kg/d of waste into valuable products. The biol needs further treatment time or to couple biodigesters-another treatment. The pig farm can be considered eco-efficient.

11.
J Clin Immunol ; 41(5): 934-943, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33523338

RESUMEN

Autosomal dominant hyper-IgE syndrome caused by dominant-negative loss-of-function mutations in signal transducer and activator of transcription factor 3 (STAT3) (STAT3-HIES) is a rare primary immunodeficiency with multisystem pathology. The quality of life in patients with STAT3-HIES is determined by not only the progressive, life-limiting pulmonary disease, but also significant skin disease including recurrent infections and abscesses requiring surgery. Our early report indicated that hematopoietic stem cell transplantation might not be effective in patients with STAT3-HIES, although a few subsequent reports have reported successful outcomes. We update on progress of our patient now with over 18 years of follow-up and report on an additional seven cases, all of whom have survived despite demonstrating significant disease-related pathology prior to transplant. We conclude that effective cure of the immunological aspects of the disease and stabilization of even severe lung involvement may be achieved by allogeneic hematopoietic stem cell transplantation. Recurrent skin infections and abscesses may be abolished. Donor TH17 cells may produce comparable levels of IL17A to healthy controls. The future challenge will be to determine which patients should best be offered this treatment and at what point in their disease history.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Síndrome de Job/terapia , Adolescente , Niño , Femenino , Humanos , Interleucina-17/sangre , Síndrome de Job/sangre , Síndrome de Job/inmunología , Masculino , Factor de Transcripción STAT3
12.
Am J Bot ; 108(2): 216-235, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33576061

RESUMEN

With more than 200 species, the genus Agave is one of the most interesting and complex groups of plants in the world, considering for instance its great diversity and adaptations. The adaptations include the production of a single, massive inflorescence (the largest among plants) where after growing for many years, sometimes more than 30, the rosette dies shortly afterward, and the remarkable coevolution with their main pollinators, nectarivorous bats, in particular of the genus Leptonycteris. The physiological adaptations of Agave species include a photosynthetic metabolism that allows efficient use of water and a large degree of succulence, helping to store water and resources for their massive flowering event. Ecologically, the agaves are keystone species on which numerous animal species depend for their subsistence due to the large amounts of pollen and nectar they produce, that support many pollinators, including bats, perching birds, hummingbirds, moths, and bees. Moreover, in many regions of Mexico and in the southwestern United States, agaves are dominant species. We describe the contributions of H. S. Gentry to the understanding of agaves and review recent advances on the study of the ecology and evolution of the genus. We analyze the present and inferred past distribution patterns of different species in the genus, describing differences in their climatic niche and adaptations to dry conditions. We interpret these patterns using molecular clock data and phylogenetic analyses and information of their coevolving pollinators and from phylogeographic, morphological, and ecological studies and discuss the prospects for their future conservation and management.


Asunto(s)
Agave , Animales , Abejas , Ecología , México , Filogenia , Polinización , Sudoeste de Estados Unidos
13.
Ecotoxicol Environ Saf ; 215: 112122, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33725489

RESUMEN

The human ingestion of mercury (Hg) from sea food is of big concern worldwide due to adverse health effects, and more specifically if shark consumption constitutes a regular part of the human diet. In this study, the total mercury (THg) concentration in muscle tissue were determined in six sympatric shark species found in a fishing vessel seized in the Galapagos Marine Reserve in 2017. The THg concentrations in shark muscle samples (n = 73) varied from 0.73 mg kg-1 in bigeye thresher sharks (Alopias superciliosus) to 8.29 mg kg-1 in silky sharks (Carcharhinus falciformis). A typical pattern of Hg bioaccumulation was observed for all shark species, with significant correlation between THg concentration and shark size for bigeye thresher sharks, pelagic thresher sharks (Alopias pelagicus) and silky sharks. Regarding human health concerns, the THg mean concentration exceeded the maximum weekly intake fish serving in all the studied species. Mass-Dependent Fractionation (MDF, δ202Hg values) and Mass-Independent Fractionation (MIF, Δ199Hg values) of Hg in whitetip sharks (Carcharhinus longimanus) and silky sharks, ranged from 0.70‰ to 1.08‰, and from 1.97‰ to 2.89‰, respectively. These high values suggest that both species are feeding in the epipelagic zone (i.e. upper 200 m of the water column). While, blue sharks (Prionace glauca), scalloped hammerhead sharks (Shyrna lewini) and thresher sharks were characterized by lower Δ199Hg and δ202Hg values, indicating that these species may focus their foraging behavior on prey of mesopelagic zone (i.e. between 200 and 1000 m depth). In conclusion, the determination of THg concentration provides straight-forward evidence of the human health risks associated with shark consumption, while mercury isotopic compositions constitute a powerful tool to trace the foraging strategies of these marine predators. CAPSULE: A double approach combining Hg concentrations with stable isotopes ratios allowed to assess ontogeny in common shark species in the area of the Galapagos Marine Reserve and the human health risks concern associated to their consumption.


Asunto(s)
Mercurio/metabolismo , Tiburones/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , Bioacumulación , Monitoreo del Ambiente/métodos , Conducta Alimentaria , Humanos , Isótopos , Mercurio/análisis , Isótopos de Mercurio , Músculos/química , Alimentos Marinos , Tiburones/fisiología , Contaminantes Químicos del Agua/análisis
14.
Semin Cell Dev Biol ; 84: 90-99, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-29242146

RESUMEN

In virtually all sexually reproducing animals, oocytes arrest in meiotic prophase and resume meiosis in a conserved biological process called meiotic maturation. Meiotic arrest enables oocytes, which are amongst the largest cells in an organism, to grow and accumulate the necessary cellular constituents required to support embryonic development. Oocyte arrest can be maintained for a prolonged period, up to 50 years in humans, and defects in the meiotic maturation process interfere with the faithful segregation of meiotic chromosomes, representing the leading cause of human birth defects and female infertility. Hormonal signaling and interactions with somatic cells of the gonad control the timing of oocyte meiotic maturation. Signaling activates the CDK1/cyclin B kinase, which plays a central role in regulating the nuclear and cytoplasmic events of meiotic maturation. Nuclear maturation encompasses nuclear envelope breakdown, meiotic spindle assembly, and chromosome segregation whereas cytoplasmic maturation involves major changes in oocyte protein translation and cytoplasmic organelles and is less well understood. Classically, meiotic maturation has been studied in organisms with large oocytes to facilitate biochemical analysis. Recently, the nematode Caenorhabditis elegans is emerging as a genetic paradigm for studying the regulation of oocyte meiotic maturation. Studies in this system have revealed conceptual, anatomical, and molecular links to oocytes in all animals including humans. This review focuses on the signaling mechanisms required to control oocyte growth and meiotic maturation in C. elegans and discusses how the downstream regulation of protein translation coordinates the completion of meiosis and the oocyte-to-embryo transition.


Asunto(s)
Desarrollo Embrionario/fisiología , Meiosis/fisiología , Oocitos/citología , Oogénesis/fisiología , Animales , Caenorhabditis elegans , Humanos , Transducción de Señal/fisiología
15.
Am J Bot ; 107(3): 510-525, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32072632

RESUMEN

PREMISE: Domestication usually involves local adaptation to environmental conditions. Cucurbita species are a promising model for studying these processes. Cucurbita moschata is the third major crop in the genus because of its economic value and because it displays high landrace diversity, but research about its genetic diversity, population structure, and phylogeography is limited. We aimed at understanding how geography and elevation shape the distribution of genetic diversity in C. moschata landraces in Mexico. METHODS: We sampled fruits from 24 localities throughout Mexico. We assessed 11 nuclear microsatellite loci, one mtDNA region, and three cpDNA regions but found no variation in cpDNA. We explored genetic structure with cluster analysis, and phylogeographic relationships with haplotype network analysis. RESULTS: Mitochondrial genetic diversity was high, and nuclear genetic differentiation among localities was intermediate compared to other domesticated Cucurbita. We found high levels of inbreeding. We recovered two mitochondrial lineages: highland (associated with the Trans-Mexican Volcanic Belt) and lowland. Nuclear microsatellites show that localities from the Yucatan Peninsula constitute a well-differentiated group. CONCLUSIONS: Mexico is an area of high diversity for C. moschata, and these landraces represent important plant genetic resources. In Mexico this species is characterized by divergence processes linked to an elevational gradient, which could be related to adaptation and may be of value for applications in agriculture. The Isthmus of Tehuantepec may be a partial barrier to gene flow. Morphological variation, agricultural management, and cultural differences may be related to this pattern of genetic structure, but further studies are needed.


Asunto(s)
Cucurbita , ADN Mitocondrial , Variación Genética , Haplotipos , México , Filogenia , Filogeografía
16.
BMC Infect Dis ; 20(1): 828, 2020 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-33176707

RESUMEN

BACKGROUND: Severe and disseminated non-tuberculous mycobacterial (NTM) infections are frequently linked to a genetic predisposition but acquired defects of the interferon gamma (IFNγ) / interleukin 12 (IL-12) pathway need to be considered in adult patients with persistent or recurrent infections. Neutralizing anti-IFNγ autoantibodies disrupting IFNγ signalling have been identified as the cause of a severe and unique acquired immunodeficiency syndrome with increased susceptibility to NTM and other intracellular pathogens. CASE PRESENTATION: An adult Asian female with a previous history of recurrent NTM infections presented with persistent diarrhea, abdominal pain, night sweats and weight loss. Severe colitis due to a simultaneous infection with cytomegalovirus (CMV) and Salmonella typhimurium was diagnosed, with both pathogens also detectable in blood samples. Imaging studies further revealed thoracic as well as abdominal lymphadenopathy and a disseminated Mycobacterium intracellulare infection was diagnosed after a lymph node biopsy. Further diagnostics revealed the presence of high-titer neutralizing anti-IFNγ autoantibodies, allowing for the diagnosis of adult-onset immunodeficiency with anti-IFNγ autoantibodies (AIIA). CONCLUSIONS: We here present a severe case of acquired immunodeficiency with anti-IFNγ autoantibodies with simultaneous, disseminated infections with both viral and microbial pathogens. The case illustrates how the diagnosis can cause considerable difficulties and is often delayed due to unusual presentations. Histological studies in our patient give further insight into the pathophysiological significance of impaired IFNγ signalling. B-cell-depleting therapy with rituximab offers a targeted treatment approach in AIIA.


Asunto(s)
Autoanticuerpos/inmunología , Infecciones por Citomegalovirus/diagnóstico , Citomegalovirus/aislamiento & purificación , Síndromes de Inmunodeficiencia/diagnóstico , Interferón gamma/inmunología , Linfadenopatía/diagnóstico , Complejo Mycobacterium avium/aislamiento & purificación , Infección por Mycobacterium avium-intracellulare/diagnóstico , Infecciones por Salmonella/diagnóstico , Salmonella typhimurium/aislamiento & purificación , Adulto , Antibacterianos/uso terapéutico , Antivirales/uso terapéutico , Autoanticuerpos/sangre , Biopsia , Infecciones por Citomegalovirus/complicaciones , Infecciones por Citomegalovirus/tratamiento farmacológico , Infecciones por Citomegalovirus/virología , Diagnóstico Tardío , Femenino , Estudios de Seguimiento , Humanos , Síndromes de Inmunodeficiencia/complicaciones , Síndromes de Inmunodeficiencia/tratamiento farmacológico , Factores Inmunológicos/uso terapéutico , Interferón gamma/metabolismo , Interleucina-12/metabolismo , Linfadenopatía/complicaciones , Linfadenopatía/tratamiento farmacológico , Linfadenopatía/patología , Infección por Mycobacterium avium-intracellulare/complicaciones , Infección por Mycobacterium avium-intracellulare/tratamiento farmacológico , Infección por Mycobacterium avium-intracellulare/microbiología , Infecciones por Salmonella/complicaciones , Infecciones por Salmonella/tratamiento farmacológico , Infecciones por Salmonella/microbiología , Resultado del Tratamiento
17.
J Mol Evol ; 87(9-10): 327-342, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31701178

RESUMEN

Twenty-nine DNA regions of plastid origin have been previously identified in the mitochondrial genome of Cucurbita pepo (pumpkin; Cucurbitaceae). Four of these regions harbor homolog sequences of rbcL, matK, rpl20-rps12 and trnL-trnF, which are widely used as molecular markers for phylogenetic and phylogeographic studies. We extracted the mitochondrial copies of these regions based on the mitochondrial genome of C. pepo and, along with published sequences for these plastome markers from 13 Cucurbita taxa, we performed phylogenetic molecular analyses to identify inter-organellar transfer events in the Cucurbita phylogeny and changes in their nucleotide substitution rates. Phylogenetic reconstruction and tree selection tests suggest that rpl20 and rbcL mitochondrial paralogs arose before Cucurbita diversification whereas the mitochondrial matK and trnL-trnF paralogs emerged most probably later, in the mesophytic Cucurbita clade. Nucleotide substitution rates increased one order of magnitude in all the mitochondrial paralogs compared to their original plastid sequences. Additionally, mitochondrial trnL-trnF sequences obtained by PCR from nine Cucurbita taxa revealed higher nucleotide diversity in the mitochondrial than in the plastid copies, likely related to the higher nucleotide substitution rates in the mitochondrial region and loss of functional constraints in its tRNA genes.


Asunto(s)
Cucurbita/genética , Genoma Mitocondrial/genética , Plastidios/genética , Evolución Biológica , Evolución Molecular , Genes de Plantas/genética , Genoma de Planta/genética , Mitocondrias/genética , Filogenia , Análisis de Secuencia de ADN
18.
Proc Biol Sci ; 286(1908): 20191440, 2019 08 14.
Artículo en Inglés | MEDLINE | ID: mdl-31409251

RESUMEN

Cucurbita pepo is an economically important crop, which consists of cultivated C. pepo ssp. pepo, and two wild taxa (C. pepo ssp. fraterna and C. pepo ssp. ovifera). We aimed at understanding the domestication and the diversity of C. pepo in Mexico. We used two chloroplast regions and nine nuclear microsatellite loci to assess the levels of genetic variation and structure for C. pepo ssp. pepo's landraces sampled in 13 locations in Mexico, five improved varieties, one C. pepo ssp. fraterna population and ornamental C. pepo ssp. ovifera. We tested four hypotheses regarding the origin of C. pepo ssp. pepo's ancestor through approximate Bayesian computation: C. pepo ssp. ovifera as the ancestor; C. pepo ssp. fraterna as the ancestor; an unknown extinct lineage as the ancestor; and C. pepo ssp. pepo as hybrid from C. pepo ssp. ovifera and C. pepo ssp. fraterna ancestors. Cucurbita pepo ssp. pepo showed high genetic variation and low genetic differentiation. Cucurbita pepo ssp. fraterna and C. pepo ssp. pepo shared two chloroplast haplotypes. The three subspecies were well differentiated for microsatellite loci. Cucurbita pepo ssp. fraterna was probably C. pepo ssp. pepo's wild ancestor, but subsequent hybridization between taxa complicate defining C. pepo ssp. pepo's ancestor.


Asunto(s)
Cucurbita/genética , Domesticación , Variación Genética , Repeticiones de Microsatélite/genética , Núcleo Celular/genética , Cloroplastos/genética , México , Filogeografía
19.
Curr Opin Infect Dis ; 32(4): 330-336, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31116133

RESUMEN

PURPOSE OF REVIEW: The current review gives a concise and updated overview of the relative new field of anticytokine autoantibodies (ACAA) and associated infections with a focus on recent findings regarding clinical manifestions, diagnostic and treatments. RECENT FINDINGS: Several recent case reports of unusual presentations of patients with neutralizing autoantibodies to IFN-γ and granulocyt macrophage colony-stimulating factor and expand the spectrum of clinical manifestations and suggest that anticytokine-mediated acquired immunodeficiency causing susceptibility to infection may be underdiagnosed. There is an expanding geographical distribution of antigranulocyt macrophage colony-stimulating factor associated Cryptococcus gattii infection. The spectrum of identified infections in patients with neutralizing antibodies to IFN-γ has a strong endemic component. Rituximab or cyclophophamide in addition to antimycobacterials could be a treatment options in refractory cases. NF-κB2 deficiency may be associated with a complex pattern of high titre neutralizing ACAA similar to autoimmune polyglandular syndrome type I and Thymoma. New technique for the detection of anticytokine antibodies are presented. Quantiferon testing, which is widely available for TB-diagnostic, may be repurposed to detect anti-IFN-γ autoantibodies. We propose that this test could be as well used to show if they are neutralizing. SUMMARY: ACAA are an emerging cause of acquired immunodeficiency which is likely underdiagnosed. Recent case reports document expanding spectra of clinical manifestations. NF-κB2 deficiency may be associated with a complex anti cytokine autoantibody pattern.


Asunto(s)
Autoanticuerpos/efectos adversos , Citocinas/antagonistas & inhibidores , Susceptibilidad a Enfermedades , Infecciones/diagnóstico , Infecciones/etiología , Infecciones/terapia , Anticuerpos Neutralizantes/inmunología , Autoanticuerpos/inmunología , Citocinas/inmunología , Susceptibilidad a Enfermedades/inmunología , Predisposición Genética a la Enfermedad , Factor Estimulante de Colonias de Granulocitos/antagonistas & inhibidores , Factor Estimulante de Colonias de Granulocitos/inmunología , Humanos , Interferón gamma/antagonistas & inhibidores , Interferón gamma/inmunología , Infecciones por Mycobacterium/diagnóstico , Infecciones por Mycobacterium/etiología , Infecciones por Mycobacterium/terapia , FN-kappa B/deficiencia , Infecciones Oportunistas/diagnóstico , Infecciones Oportunistas/etiología , Infecciones Oportunistas/terapia , Índice de Severidad de la Enfermedad
20.
Mol Phylogenet Evol ; 128: 38-54, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30036701

RESUMEN

Knowledge of the role of geographical and ecological events associated to the divergence process of wild progenitors is important to understand the process of domestication. We analysed the temporal, spatial and ecological patterns of the diversification of Cucurbita, an American genus of worldwide economic importance. We conducted a phylogenetic analysis based on six chloroplast regions (5907 bp) to estimate diversification rates and dates of divergence between taxa. This is the first phylogenetic study to include C. radicans, a wild species that is endemic to the Trans Mexican Volcanic Belt. We performed analysis of ancestral area reconstruction and paleoreconstructions of species distribution models to understand shifts in wild species ranges. We used principal component analysis (PCA) and multivariate analysis of variance (MANOVA) to evaluate the environmental differentiation among taxa within each clade. The phylogenetic analyses showed good support for at least six independent domestication events in Cucurbita. The genus Cucurbita showed a time of divergence of 11.24 Ma (6.88-17 Ma 95% HDP), and the dates of divergence between taxa within each group ranged from 0.35 to 6.58 Ma, being the divergence between C. lundelliana and C. okeechobeensis subsp. martinezii the most recent. The diversification rate of the genus was constant through time. The diversification of most wild taxa occurred during the Pleistocene, and its date of divergence is concordant with the dates of divergence reported for specialized bees of the genera Xenoglossa and Peponapis, suggesting a process of coevolution between Cucurbita and their main pollinators that should be further investigated. Tests of environmental differentiation together with ancestral area reconstruction and species distribution models past projections suggest that divergence was promoted by the onset of geographic barriers and secondary range contraction and by expansion related to glacial-interglacial cycles.


Asunto(s)
Cucurbita/clasificación , Ecosistema , Filogenia , Filogeografía , Biodiversidad , Cloroplastos/genética , Análisis de Componente Principal , Factores de Tiempo
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