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Despite the success of the BNT162b2 mRNA vaccine, the immunological mechanisms that underlie its efficacy are poorly understood. Here we analyzed the innate and adaptive responses to BNT162b2 in mice, and show that immunization stimulated potent antibody and antigen-specific T cell responses, as well as strikingly enhanced innate responses after secondary immunization, which was concurrent with enhanced serum interferon (IFN)-γ levels 1 d following secondary immunization. Notably, we found that natural killer cells and CD8+ T cells in the draining lymph nodes are the major producers of this circulating IFN-γ. Analysis of knockout mice revealed that induction of antibody and T cell responses to BNT162b2 was not dependent on signaling via Toll-like receptors 2, 3, 4, 5 and 7 nor inflammasome activation, nor the necroptosis or pyroptosis cell death pathways. Rather, the CD8+ T cell response induced by BNT162b2 was dependent on type I interferon-dependent MDA5 signaling. These results provide insights into the molecular mechanisms by which the BNT162b2 vaccine stimulates immune responses.
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Linfocitos T CD8-positivos , Vacunas , Inmunidad Adaptativa , Animales , Vacuna BNT162 , Humanos , Inmunidad Innata , Ratones , Vacunas Sintéticas , Vacunas de ARNmRESUMEN
BACKGROUND: Conventional basophil activation tests (BATs) measure basophil activation by the increased expression of CD63. Previously, fluorophore-labeled avidin, a positively-charged molecule, was found to bind to activated basophils, which tend to expose negatively charged granule constituents during degranulation. This study further compares avidin versus CD63 as basophil activation biomarkers in classifying peanut allergy. METHODS: Seventy subjects with either a peanut allergy (N = 47), a food allergy other than peanut (N = 6), or no food allergy (N = 17) were evaluated. We conducted BATs in response to seven peanut extract (PE) concentrations (0.01-10,000 ng/mL) and four control conditions (no stimulant, anti-IgE, fMLP (N-formylmethionine-leucyl-phenylalanine), and anti-FcεRI). We measured avidin binding and CD63 expression on basophils with flow cytometry. We evaluated logistic regression and XGBoost models for peanut allergy classification and feature identification. RESULTS: Avidin binding was correlated with CD63 expression. Both markers discriminated between subjects with and without a peanut allergy. Although small by percentage, an avidin+ /CD63- cell subset was found in all allergic subjects tested, indicating that the combination of avidin and CD63 could allow a more comprehensive identification of activated basophils. Indeed, we obtained the best classification accuracy (97.8% sensitivity, 96.7% specificity) by combining avidin and CD63 across seven PE doses. Similar accuracy was obtained by combining PE dose of 10,000 ng/mL for avidin and PE doses of 10 and 100 ng/mL for CD63. CONCLUSIONS: Avidin and CD63 are reliable BAT activation markers associated with degranulation. Their combination enhances the identification of activated basophils and improves the classification accuracy of peanut allergy.
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Prueba de Desgranulación de los Basófilos , Hipersensibilidad al Cacahuete , Humanos , Hipersensibilidad al Cacahuete/diagnóstico , Hipersensibilidad al Cacahuete/metabolismo , Avidina/metabolismo , Inmunoglobulina E/metabolismo , Basófilos/metabolismo , Citometría de Flujo , Arachis , Tetraspanina 30/metabolismoRESUMEN
BACKGROUND: During the COVID-19 pandemic, novel nanoparticle-based mRNA vaccines were developed. A small number of individuals developed allergic reactions to these vaccines although the mechanisms remain undefined. METHODS: To understand COVID-19 vaccine-mediated allergic reactions, we enrolled 19 participants who developed allergic events within 2 h of vaccination and 13 controls, nonreactors. Using standard hemolysis assays, we demonstrated that sera from allergic participants induced stronger complement activation compared to nonallergic subjects following ex vivo vaccine exposure. RESULTS: Vaccine-mediated complement activation correlated with anti-polyethelyne glycol (PEG) IgG (but not IgM) levels while anti-PEG IgE was undetectable in all subjects. Depletion of total IgG suppressed complement activation in select individuals. To investigate the effects of vaccine excipients on basophil function, we employed a validated indirect basophil activation test that stratified the allergic populations into high and low responders. Complement C3a and C5a receptor blockade in this system suppressed basophil response, providing strong evidence for complement involvement in vaccine-mediated basophil activation. Single-cell multiome analysis revealed differential expression of genes encoding the cytokine response and Toll-like receptor (TLR) pathways within the monocyte compartment. Differential chromatin accessibility for IL-13 and IL-1B genes was found in allergic and nonallergic participants, suggesting that in vivo, epigenetic modulation of mononuclear phagocyte immunophenotypes determines their subsequent functional responsiveness, contributing to the overall physiologic manifestation of vaccine reactions. CONCLUSION: These findings provide insights into the mechanisms underlying allergic reactions to COVID-19 mRNA vaccines, which may be used for future vaccine strategies in individuals with prior history of allergies or reactions and reduce vaccine hesitancy.
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BACKGROUND: The impact of exposure to air pollutants, such as fine particulate matter (PM), on the immune system and its consequences on pediatric asthma, are not well understood. We investigated whether ambient levels of fine PM with aerodynamic diameter ≤2.5 microns (PM2.5 ) are associated with alterations in circulating monocytes in children with or without asthma. METHODS: Monocyte phenotyping was performed by cytometry time-of-flight (CyTOF). Cytokines were measured using cytometric bead array and Luminex assay. ChIP-Seq was utilized to address histone modifications in monocytes. RESULTS: Increased exposure to ambient PM2.5 was linked to specific monocyte subtypes, particularly in children with asthma. Mechanistically, we hypothesized that innate trained immunity is evoked by a primary exposure to fine PM and accounts for an enhanced inflammatory response after secondary stimulation in vitro. We determined that the trained immunity was induced in circulating monocytes by fine particulate pollutants, and it was characterized by the upregulation of proinflammatory mediators, such as TNF, IL-6, and IL-8, upon stimulation with house dust mite or lipopolysaccharide. This phenotype was epigenetically controlled by enhanced H3K27ac marks in circulating monocytes. CONCLUSION: The specific alterations of monocytes after ambient pollution exposure suggest a possible prognostic immune signature for pediatric asthma, and pollution-induced trained immunity may provide a potential therapeutic target for asthmatic children living in areas with increased air pollution.
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Contaminantes Atmosféricos , Contaminación del Aire , Asma , Humanos , Material Particulado/efectos adversos , Monocitos , Inmunidad Entrenada , Contaminantes Atmosféricos/efectos adversos , Contaminantes Atmosféricos/análisis , Asma/etiología , Asma/inducido químicamente , Contaminación del Aire/efectos adversosRESUMEN
MOTIVATION: For immune system monitoring in large-scale studies at the single-cell resolution using CyTOF, (semi-)automated computational methods are applied for annotating live cells of mixed cell types. Here, we show that the live cell pool can be highly enriched with undefined heterogeneous cells, i.e. 'ungated' cells, and that current semi-automated approaches ignore their modeling resulting in misclassified annotations. RESULT: We introduce 'CyAnno', a novel semi-automated approach for deconvoluting the unlabeled cytometry dataset based on a machine learning framework utilizing manually gated training data that allows the integrative modeling of 'gated' cell types and the 'ungated' cells. By applying this framework on several CyTOF datasets, we demonstrated that including the 'ungated' cells can lead to a significant increase in the precision of the 'gated' cell types prediction. CyAnno can be used to identify even a single cell type, including rare cells, with higher efficacy than current state-of-the-art semi-automated approaches. AVAILABILITY AND IMPLEMENTATION: The CyAnno is available as a python script with a user-manual and sample dataset at https://github.com/abbioinfo/CyAnno. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
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Células , Aprendizaje Automático , Biología Computacional , Análisis de la Célula IndividualRESUMEN
BACKGROUND: Multifood oral immunotherapy (mOIT) with adjunctive anti-IgE (omalizumab, XOLAIR® ) treatment affords safe, effective, and rapid desensitization to multiple foods, although the specific immune mechanisms mediating this desensitization remain to be fully elucidated. METHODS: Participants in our phase 2 mOIT trial (NCT02643862) received omalizumab from baseline to week 16 and mOIT from week 8 to week 36. We compared the immune profile of PBMCs and plasma taken at baseline, week 8, and week 36 using high-dimensional mass cytometry, component-resolved diagnostics, the indirect basophil activation test, and Luminex. RESULTS: We found (i) decreased frequency of IL-4+ peanut-reactive CD4+ T cells and a marked downregulation of GPR15 expression and CXCR3 frequency among γδ and CD8+ T-cell subsets at week 8 during the initial, omalizumab-alone induction phase; (ii) significant upregulation of the skin-homing receptor CCR4 in peanut-reactive CD4+ T and Th2 effector memory (EM) cells and of cutaneous lymphocyte-associated antigen (CLA) in peanut-reactive CD8+ T and CD8+ EM cells; (iii) downregulation of CD86 expression among antigen-presenting cell subsets; and (iv) reduction in pro-inflammatory cytokines, notably IL-17, at week 36 post-OIT. We also observed significant attenuation of the Th2 phenotype post-OIT, defined by downregulation of IL-4 peanut-reactive T cells and OX40 in Th2EM cells, increased allergen component-specific IgG4/IgE ratio, and decreased allergen-driven activation of indirectly sensitized basophils. CONCLUSIONS: This exploratory study provides novel comprehensive insight into the immune underpinnings of desensitization through omalizumab-facilitated mOIT. Moreover, this study provides encouraging results to support the complex immune changes that can be induced by OIT.
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Omalizumab , Hipersensibilidad al Cacahuete , Administración Oral , Alérgenos , Desensibilización Inmunológica , Humanos , Inmunoglobulina E , Omalizumab/uso terapéuticoRESUMEN
The Pti1 kinase was identified from a reverse genetic screen as contributing to pattern-triggered immunity (PTI) against Pseudomonas syringae pv. tomato (Pst). The tomato genome has two Pti1 genes, referred to as Pti1a and Pti1b. A hairpin-Pti1 (hpPti1) construct was developed and was used to generate two independent stable transgenic tomato lines that had reduced transcript abundance of both genes. In response to P. syringae pv. tomato inoculation, these hpPti1 plants developed more severe disease symptoms, supported higher bacterial populations, and had reduced transcript accumulation of PTI-associated genes, as compared with wild-type plants. In response to two flagellin-derived peptides, the hpPti1 plants produced lesser amounts of reactive oxygen species (ROS) but showed no difference in mitogen-activated protein kinase (MAPK). Synthetic Pti1a and Pti1b genes designed to avoid silencing were transiently expressed in the hpPti1 plants and restored the ability of the plants to produce wild-type levels of ROS. Our results identify a new component of PTI in tomato that, because it affects ROS production but not MAPK signaling, appears to act early in the immune response.
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Resistencia a la Enfermedad , Flagelina/farmacología , Péptidos/farmacología , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/metabolismo , Pseudomonas syringae/fisiología , Especies Reactivas de Oxígeno/metabolismo , Solanum lycopersicum/enzimología , Bioensayo , Muerte Celular/efectos de los fármacos , Resistencia a la Enfermedad/efectos de los fármacos , Resistencia a la Enfermedad/genética , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Silenciador del Gen , Genes de Plantas , Prueba de Complementación Genética , Solanum lycopersicum/genética , Solanum lycopersicum/microbiología , Enfermedades de las Plantas/genética , Inmunidad de la Planta/efectos de los fármacos , Plantas Modificadas Genéticamente , Pseudomonas syringae/efectos de los fármacos , Análisis de Secuencia de ARNAsunto(s)
Hipersensibilidad a los Alimentos , Mastocitos , Humanos , Mastocitos/fisiología , SelenometioninaRESUMEN
BACKGROUND: Effector proteins are translocated into host cells by plant-pathogens to undermine pattern-triggered immunity (PTI), the plant response to microbe-associated molecular patterns that interferes with the infection process. Individual effectors are found in variable repertoires where some constituents target the same pathways. The effector protein AvrPto from Pseudomonas syringae has a core domain (CD) and C-terminal domain (CTD) that each promotes bacterial growth and virulence in tomato. The individual contributions of each domain and whether they act redundantly is unknown. RESULTS: We use RNA-Seq to elucidate the contribution of the CD and CTD to the suppression of PTI in tomato leaves 6 h after inoculation. Unexpectedly, each domain alters transcript levels of essentially the same genes but to a different degree. This difference, when quantified, reveals that although targeting the same host genes, the two domains act synergistically. AvrPto has a relatively greater effect on genes whose expression is suppressed during PTI, and the effect on these genes appears to be diminished by saturation. CONCLUSIONS: RNA-Seq profiles can be used to observe relative contributions of effector subdomains to PTI suppression. Our analysis shows the CD and CTD multiplicatively affect the same gene transcript levels with a greater relative impact on genes whose expression is suppressed during PTI. The higher degree of up-regulation versus down-regulation during PTI is plausibly an evolutionary adaptation against effectors that target immune signaling.
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Proteínas Bacterianas/metabolismo , Enfermedades de las Plantas/microbiología , Inmunidad de la Planta/genética , Pseudomonas syringae/patogenicidad , Solanum lycopersicum/genética , Transcriptoma , Regulación hacia Abajo , Regulación de la Expresión Génica de las Plantas , Solanum lycopersicum/microbiología , Análisis de Secuencia de ARN , Regulación hacia ArribaAsunto(s)
Alérgenos/inmunología , Arachis/inmunología , Linfocitos T CD8-positivos/inmunología , Hipersensibilidad al Cacahuete/inmunología , Péptidos/inmunología , Proteínas de Plantas/inmunología , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Inmunoglobulina E/inmunología , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
BACKGROUND: Decades of intensive tomato breeding using wild-species germplasm have resulted in the genomes of domesticated germplasm (Solanum lycopersicum) being intertwined with introgressions from their wild relatives. Comparative analysis of genomes among cultivated tomatoes and wild species that have contributed genetic variation can help identify desirable genes, such as those conferring disease resistance. The ability to identify introgression position, borders, and contents can reveal ancestral origins and facilitate harnessing of wild variation in crop breeding. RESULTS: Here we present the whole-genome sequences of two tomato inbreds, Gh13 and BTI-87, both carrying the begomovirus resistance locus Ty-3 introgressed from wild tomato species. Introgressions of different sizes on chromosome 6 of Gh13 and BTI-87, both corresponding to the Ty-3 region, were identified as from a source close to the wild species S. chilense. Other introgressions were identified throughout the genomes of the inbreds and showed major differences in the breeding pedigrees of the two lines. Interestingly, additional large introgressions from the close tomato relative S. pimpinellifolium were identified in both lines. Some of the polymorphic regions were attributed to introgressions in the reference Heinz 1706 genome, indicating wild genome sequences in the reference tomato genome. CONCLUSIONS: The methods developed in this work can be used to delineate genome introgressions, and subsequently contribute to development of molecular markers to aid phenotypic selection, fine mapping and discovery of candidate genes for important phenotypes, and for identification of novel variation for tomato improvement. These universal methods can easily be applied to other crop plants.
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Begomovirus/genética , Variación Genética , Genoma de Planta/genética , Solanum lycopersicum/genética , Solanum/genética , Secuencia de Bases , Mapeo Cromosómico , Resistencia a la Enfermedad , Genotipo , Endogamia , Solanum lycopersicum/inmunología , Solanum lycopersicum/virología , Datos de Secuencia Molecular , Fenotipo , Filogenia , Polimorfismo de Nucleótido Simple , Análisis de Secuencia de ADN , Solanum/inmunología , Solanum/virologíaRESUMEN
Understanding antigen-specific T-cell responses, for example, following virus infections or allergen exposure, is of high relevance for the development of vaccines and therapeutics. We aimed on optimizing immunophenotyping of T cells after antigen stimulation by improving staining procedures for flow and mass cytometry. Our method can be used for primary cells of both mouse and human origin for the detection of low-frequency T-cell response using a dual-barcoding system for individual samples and conditions. First, live-cell barcoding was performed using anti-CD45 antibodies prior to an in vitro T-cell stimulation assay. Second, to discriminate between stimulation conditions and prevent cell loss, sample barcoding was combined with a commercial barcoding solution. This dual-barcoding approach is cell sparing and, therefore, particularly relevant for samples with low cell numbers. To further reduce cell loss and to increase debarcoding efficiency of multiplexed samples, we combined our dual-barcoding approach with a new centrifugation-free washing system by laminar flow (Curiox™). Finally, to demonstrate the benefits of our established protocol, we assayed virus-specific T-cell response in SARS-CoV-2-vaccinated and SARS-CoV-2-infected patients and compared with healthy non-exposed individuals by a high-parameter CyTOF analysis. We could reveal a heterogeneity of phenotypes among responding CD4, CD8, and gd-T cells following antigen-specific stimulations. Our protocol allows to assay antigen-specific responses of minute populations of T cells to virus-derived peptides, allergens, or other antigens from the same donor sample, in order to investigate qualitative and quantitative differences.
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Antígenos , Linfocitos T , Humanos , Animales , Ratones , Citometría de Flujo/métodos , Inmunofenotipificación , Coloración y Etiquetado , Linfocitos T CD8-positivosRESUMEN
Food allergies are a leading cause of anaphylaxis, and allergen-specific immune responses in both the innate and the adaptive immune system play key roles in its pathogenesis. We conducted a comprehensive phenotypic and functional investigation of immune cell responses from nonallergic (NA) and peanut allergic (PA) participants cultured with media alone or peanut protein and found, surprisingly, that NK cell activation was strongly associated with the immune response to allergen in PA participants. Peanut-responsive NK cells manifested a distinct expression pattern in PA participants compared with NA participants. Allergen-activated NK cells expressed both Th2 and immune regulatory cytokines, hinting at a potential functional role in mediating and regulating the Th2 allergic response. Depletion of CD3+ T cells attenuated the response of NK cells to peanut-allergen stimulation, suggesting that peanut-responsive NK cells are T cell dependent. We also showed that oral immune therapy was associated with decreased NK responses to peanut allergen stimulation in vitro. These results demonstrate that NK cells are associated with the food-allergic immune response, and the magnitude of this mobilized cell population suggests that they play a functional role in allergic immunity.
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Hipersensibilidad a los Alimentos , Hipersensibilidad al Cacahuete , Alérgenos , Arachis , Citocinas/metabolismo , Humanos , Células Asesinas Naturales , Hipersensibilidad al Cacahuete/terapiaRESUMEN
IgE-mediated food allergies in infants are a significant health concern, with peanut allergy being of particular interest due to its prevalence and severity. Among individuals who produce peanut-specific IgE some experience no adverse reaction on peanut consumption. This asymptomatic phenotype is known as sensitized tolerance. To elucidate the immune environment of peanut sensitized tolerant and clinically allergic one-year-olds, high-dimensional mass cytometry was conducted as part of the HealthNuts study. The resulting data includes peripheral blood mononuclear cells from 36 participants encompassing non-allergic, peanut sensitized with tolerance, and clinically peanut allergic infants. The raw mass cytometry data is described here and freely available for reuse through the Immunology Database and Analysis Portal (ImmPort). Additional allergy information and serum vitamin D levels of the participants were measured and are also included in the data upload. These high-dimensional mass cytometry data, when combined with clinical information, offer a broad immune profile of peanut allergic and sensitized tolerant infants.
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Hipersensibilidad al Cacahuete , Arachis , Inmunoglobulina E , Leucocitos , Leucocitos Mononucleares , Hipersensibilidad al Cacahuete/sangre , Citofotometría , Humanos , LactanteRESUMEN
While food allergy oral immunotherapy (OIT) can provide safe and effective desensitization (DS), the immune mechanisms underlying development of sustained unresponsiveness (SU) following a period of avoidance are largely unknown. Here, we compare high dimensional phenotypes of innate and adaptive immune cell subsets of participants in a previously reported, phase 2 randomized, controlled, peanut OIT trial who achieved SU vs. DS (no vs. with allergic reactions upon food challenge after a withdrawal period; n = 21 vs. 30 respectively among total 120 intent-to-treat participants). Lower frequencies of naïve CD8+ T cells and terminally differentiated CD57+CD8+ T cell subsets at baseline (pre-OIT) are associated with SU. Frequency of naïve CD8+ T cells shows a significant positive correlation with peanut-specific and Ara h 2-specific IgE levels at baseline. Higher frequencies of IL-4+ and IFNγ+ CD4+ T cells post-OIT are negatively correlated with SU. Our findings provide evidence that an immune signature consisting of certain CD8+ T cell subset frequencies is potentially predictive of SU following OIT.
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Hipersensibilidad al Cacahuete , Hipersensibilidad al Cacahuete/terapia , Desensibilización Inmunológica/métodos , Inmunoglobulina E , Linfocitos T CD8-positivos , Estudios de Factibilidad , Administración Oral , Arachis , Alérgenos , Factores Inmunológicos , Diferenciación CelularRESUMEN
Importance: As of May 2021, more than 32 million cases of COVID-19 have been confirmed in the United States, resulting in more than 615â¯000 deaths. Anaphylactic reactions associated with the Food and Drug Administration (FDA)-authorized mRNA COVID-19 vaccines have been reported. Objective: To characterize the immunologic mechanisms underlying allergic reactions to these vaccines. Design, Setting, and Participants: This case series included 22 patients with suspected allergic reactions to mRNA COVID-19 vaccines between December 18, 2020, and January 27, 2021, at a large regional health care network. Participants were individuals who received at least 1 of the following International Statistical Classification of Diseases and Related Health Problems, Tenth Revision anaphylaxis codes: T78.2XXA, T80.52XA, T78.2XXD, or E949.9, with documentation of COVID-19 vaccination. Suspected allergy cases were identified and invited for follow-up allergy testing. Exposures: FDA-authorized mRNA COVID-19 vaccines. Main Outcomes and Measures: Allergic reactions were graded using standard definitions, including Brighton criteria. Skin prick testing was conducted to polyethylene glycol (PEG) and polysorbate 80 (P80). Histamine (1 mg/mL) and filtered saline (negative control) were used for internal validation. Basophil activation testing after stimulation for 30 minutes at 37 °C was also conducted. Concentrations of immunoglobulin (Ig) G and IgE antibodies to PEG were obtained to determine possible mechanisms. Results: Of 22 patients (20 [91%] women; mean [SD] age, 40.9 [10.3] years; 15 [68%] with clinical allergy history), 17 (77%) met Brighton anaphylaxis criteria. All reactions fully resolved. Of patients who underwent skin prick tests, 0 of 11 tested positive to PEG, 0 of 11 tested positive to P80, and 1 of 10 (10%) tested positive to the same brand of mRNA vaccine used to vaccinate that individual. Among these same participants, 10 of 11 (91%) had positive basophil activation test results to PEG and 11 of 11 (100%) had positive basophil activation test results to their administered mRNA vaccine. No PEG IgE was detected; instead, PEG IgG was found in tested individuals who had an allergy to the vaccine. Conclusions and Relevance: Based on this case series, women and those with a history of allergic reactions appear at have an elevated risk of mRNA vaccine allergy. Immunological testing suggests non-IgE-mediated immune responses to PEG may be responsible in most individuals.
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Vacunas contra la COVID-19/efectos adversos , Hipersensibilidad/diagnóstico , Adolescente , Adulto , Anciano , Vacunas contra la COVID-19/uso terapéutico , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/diagnóstico , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Femenino , Humanos , Hipersensibilidad/epidemiología , Masculino , Persona de Mediana Edad , Factores de Riesgo , Estados Unidos/epidemiología , United States Food and Drug Administration/organización & administración , United States Food and Drug Administration/estadística & datos numéricos , Vacunación/efectos adversosRESUMEN
IgE-mediated peanut allergic is common, often serious, and usually lifelong. Not all individuals who produce peanut-specific IgE will react upon consumption of peanut and can eat the food without adverse reactions, known as sensitized tolerance. Here, we employ high-dimensional mass cytometry to define the circulating immune cell signatures associated with sensitized tolerance and clinical allergy to peanut in the first year of life. Key features of clinical peanut allergic are increased frequency of activated B cells (CD19hiHLADRhi), overproduction of TNFα and increased frequency of peanut-specific memory CD4 T cells. Infants with sensitized tolerance display reduced frequency but hyper-responsive naive CD4 T cells and an increased frequency of plasmacytoid dendritic cells. This work demonstrates the utility and power of high-dimensional mass cytometry analysis to interrogate the cellular interactions that are associated with allergic sensitization and clinical food allergy in the first year of life.
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Alérgenos/inmunología , Arachis/inmunología , Tolerancia Inmunológica/inmunología , Inmunoglobulina E/inmunología , Hipersensibilidad al Cacahuete/inmunología , Linfocitos B/inmunología , Linfocitos B/metabolismo , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Células Cultivadas , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Femenino , Humanos , Inmunoglobulina E/metabolismo , Memoria Inmunológica , Lactante , Masculino , Espectrometría de Masas/métodos , Hipersensibilidad al Cacahuete/diagnóstico , Cultivo Primario de Células , Factor de Necrosis Tumoral alfa/inmunología , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Plants and animals detect the presence of potential pathogens through the perception of conserved microbial patterns by cell surface receptors. Certain solanaceous plants, including tomato, potato and pepper, detect flgII-28, a region of bacterial flagellin that is distinct from that perceived by the well-characterized FLAGELLIN-SENSING 2 receptor. Here we identify and characterize the receptor responsible for this recognition in tomato, called FLAGELLIN-SENSING 3. This receptor binds flgII-28 and enhances immune responses leading to a reduction in bacterial colonization of leaf tissues. Further characterization of FLS3 and its signalling pathway could provide new insights into the plant immune system and transfer of the receptor to other crop plants offers the potential of enhancing resistance to bacterial pathogens that have evolved to evade FLS2-mediated immunity.
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Flagelina/metabolismo , Inmunidad de la Planta , Proteínas de Plantas/genética , Proteínas Quinasas/genética , Solanum lycopersicum/genética , Solanum lycopersicum/inmunología , Solanum lycopersicum/microbiología , Hojas de la Planta/inmunología , Hojas de la Planta/microbiología , Proteínas de Plantas/metabolismo , Proteínas Quinasas/metabolismo , Transducción de SeñalRESUMEN
Bacterial speck disease caused by Pseudomonas syringae pv. tomato (Pst) is a persistent problem on tomato (Solanum lycopersicum L.). Resistance against race 0 Pst strains is conferred by the Pto protein, which recognizes either of two pathogen effectors: AvrPto or AvrPtoB. However, current tomato varieties do not have resistance to the increasingly common race 1 strains, which lack these effectors. We identified accessions of Solanum habrochaites S. Knapp & D. M. Spooner that are resistant to the race 1 strain T1. Genome sequence comparisons of T1 and two Pst strains that are virulent on these accessions suggested that known microbe-associated molecular patterns (MAMPs) or effectors are not involved in the resistance. We developed an F2 population from a cross between one T1-resistant accession, LA2109, and a susceptible tomato cultivar to investigate the genetic basis of this resistance. Linkage analysis using whole-genome sequence of 58 F2 plants identified quantitative trait loci (QTL), qRph1, in a 5.8-Mb region on chromosome 2, and qRph2, in a 52.4-Mb region on chromosome 8, which account for 24 and 26% of the phenotypic variability, respectively. High-resolution mapping of qRph1 confirmed it contributed to T1 resistance and delimited it to a 1060-kb region containing 139 genes, including three encoding receptor-like proteins (RLPs) and 17 encoding receptor-like protein kinases (RLKs). One RLK gene, Solyc02g072470, is a promising candidate for qRph1, as it is highly expressed in LA2109 and induced on treatment with MAMPs. qRph1 might be useful for enhancing resistance to race 1 strains and its future characterization could provide insights into the plant immune system.