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1.
Plant Cell ; 35(1): 218-238, 2023 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-36066192

RESUMO

Ensuring food security for an ever-growing global population while adapting to climate change is the main challenge for agriculture in the 21st century. Although new technologies are being applied to tackle this problem, we are approaching a plateau in crop improvement using conventional breeding. Recent advances in CRISPR/Cas9-mediated gene engineering have paved the way to accelerate plant breeding to meet this increasing demand. However, many traits are governed by multiple small-effect genes operating in complex interactive networks. Here, we present the gene discovery pipeline BREEDIT, which combines multiplex genome editing of whole gene families with crossing schemes to improve complex traits such as yield and drought tolerance. We induced gene knockouts in 48 growth-related genes into maize (Zea mays) using CRISPR/Cas9 and generated a collection of over 1,000 gene-edited plants. The edited populations displayed (on average) 5%-10% increases in leaf length and up to 20% increases in leaf width compared with the controls. For each gene family, edits in subsets of genes could be associated with enhanced traits, allowing us to reduce the gene space to be considered for trait improvement. BREEDIT could be rapidly applied to generate a diverse collection of mutants to identify promising gene modifications for later use in breeding programs.


Assuntos
Edição de Genes , Zea mays , Zea mays/genética , Sistemas CRISPR-Cas/genética , Plantas Geneticamente Modificadas/genética , Herança Multifatorial , Melhoramento Vegetal , Genoma de Planta/genética
2.
Plant J ; 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38713824

RESUMO

CRISPR/Cas9 is currently the most powerful tool to generate mutations in plant genomes and more efficient tools are needed as the scale of experiments increases. In the model plant Arabidopsis, the choice of the promoter driving Cas9 expression is critical to generate germline mutations. Several optimal promoters have been reported. However, it is unclear which promoter is ideal as they have not been thoroughly tested side by side. Furthermore, most plant vectors still use one of the two Cas9 nuclear localization sequence (NLS) configurations initially reported. We genotyped more than 6000 Arabidopsis T2 plants to test seven promoters and six types of NLSs across 14 targets to systematically improve the generation of single and multiplex inheritable mutations. We found that the RPS5A promoter and bipartite NLS were individually the most efficient components. When combined, 99% of T2 plants contained at least one knockout (KO) mutation and 84% contained 4- to 7-plex KOs, the highest multiplexing KO rate in Arabidopsis to date. These optimizations will be useful to generate higher-order KOs in the germline of Arabidopsis and will likely be applicable to other CRISPR systems as well.

3.
Eur J Immunol ; 54(2): e2350434, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37971166

RESUMO

The initiation of tissue remodeling following damage is a critical step in preventing the development of immune-mediated diseases. Several factors contribute to mucosal healing, leading to innovative therapeutic approaches for managing intestinal disorders. However, uncovering alternative targets and gaining mechanistic insights are imperative to enhance therapy efficacy and broaden its applicability across different intestinal diseases. Here we demonstrate that Nmes1, encoding for Normal Mucosa of Esophagus-Specific gene 1, also known as Aa467197, is a novel regulator of mucosal healing. Nmes1 influences the macrophage response to the tissue remodeling cytokine IL-4 in vitro. In addition, using two murine models of intestinal damage, each characterized by a type 2-dominated environment with contrasting functions, the ablation of Nmes1 results in decreased intestinal regeneration during the recovery phase of colitis, while enhancing parasitic egg clearance and reducing fibrosis during the advanced stages of Schistosoma mansoni infection. These outcomes are associated with alterations in CX3CR1+ macrophages, cells known for their wound-healing potential in the inflamed colon, hence promising candidates for cell therapies. All in all, our data indicate Nmes1 as a novel contributor to mucosal healing, setting the basis for further investigation into its potential as a new target for the treatment of colon-associated inflammation.


Assuntos
Colite , Mucosa Intestinal , Animais , Camundongos , Colite/tratamento farmacológico , Citocinas , Intestinos , Cicatrização
4.
Nucleic Acids Res ; 51(7): e37, 2023 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-36718951

RESUMO

Multiplex amplicon sequencing is a versatile method to identify genetic variation in natural or mutagenized populations through eco-tilling or multiplex CRISPR screens. Such genotyping screens require reliable and specific primer designs, combined with simultaneous gRNA design for CRISPR screens. Unfortunately, current tools are unable to combine multiplex gRNA and primer design in a high-throughput and easy-to-use manner with high design flexibility. Here, we report the development of a bioinformatics tool called SMAP design to overcome these limitations. We tested SMAP design on several plant and non-plant genomes and obtained designs for more than 80-90% of the target genes, depending on the genome and gene family. We validated the designs with Illumina multiplex amplicon sequencing and Sanger sequencing in Arabidopsis, soybean, and maize. We also used SMAP design to perform eco-tilling by tilling PCR amplicons across nine candidate genes putatively associated with haploid induction in Cichorium intybus. We screened 60 accessions of chicory and witloof and identified thirteen knockout haplotypes and their carriers. SMAP design is an easy-to-use command-line tool that generates highly specific gRNA and/or primer designs for any number of loci for CRISPR or natural variation screens and is compatible with other SMAP modules for seamless downstream analysis.


Assuntos
Variação Genética , Reação em Cadeia da Polimerase Multiplex , Software , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Sistemas CRISPR-Cas , Genoma , Genótipo
5.
J Physiol ; 602(1): 153-181, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37987552

RESUMO

The whisker system is widely used as a model system for understanding sensorimotor integration. Purkinje cells in the crus regions of the cerebellum have been reported to linearly encode whisker midpoint, but it is unknown whether the paramedian and simplex lobules as well as their target neurons in the cerebellar nuclei also encode whisker kinematics and if so which ones. Elucidating how these kinematics are represented throughout the cerebellar hemisphere is essential for understanding how the cerebellum coordinates multiple sensorimotor modalities. Exploring the cerebellar hemisphere of mice using optogenetic stimulation, we found that whisker movements can be elicited by stimulation of Purkinje cells in not only crus1 and crus2, but also in the paramedian lobule and lobule simplex; activation of cells in the medial paramedian lobule had on average the shortest latency, whereas that of cells in lobule simplex elicited similar kinematics as those in crus1 and crus2. During spontaneous whisking behaviour, simple spike activity correlated in general better with velocity than position of the whiskers, but it varied between protraction and retraction as well as per lobule. The cerebellar nuclei neurons targeted by the Purkinje cells showed similar activity patterns characterized by a wide variety of kinematic signals, yet with a dominance for velocity. Taken together, our data indicate that whisker movements are much more prominently and diversely represented in the cerebellar cortex and nuclei than assumed, highlighting the rich repertoire of cerebellar control in the kinematics of movements that can be engaged during coordination. KEY POINTS: Excitation of Purkinje cells throughout the cerebellar hemispheres induces whisker movement, with the shortest latency and longest duration within the paramedian lobe. Purkinje cells have differential encoding for the fast and slow components of whisking. Purkinje cells encode not only the position but also the velocity of whiskers. Purkinje cells with high sensitivity for whisker velocity are preferentially located in the medial part of lobule simplex, crus1 and lateral paramedian. In the downstream cerebellar nuclei, neurons with high sensitivity for whisker velocity are located at the intersection between the medial and interposed nucleus.


Assuntos
Cerebelo , Vibrissas , Camundongos , Animais , Vibrissas/fisiologia , Fenômenos Biomecânicos , Cerebelo/fisiologia , Células de Purkinje/fisiologia , Córtex Cerebelar
6.
New Phytol ; 241(2): 687-702, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37950543

RESUMO

Hypocotyl elongation is controlled by several signals and is a major characteristic of plants growing in darkness or under warm temperature. While already several molecular mechanisms associated with this process are known, protein degradation and associated E3 ligases have hardly been studied in the context of warm temperature. In a time-course phosphoproteome analysis on Arabidopsis seedlings exposed to control or warm ambient temperature, we observed reduced levels of diverse proteins over time, which could be due to transcription, translation, and/or degradation. In addition, we observed differential phosphorylation of the LRR F-box protein SLOMO MOTION (SLOMO) at two serine residues. We demonstrate that SLOMO is a negative regulator of hypocotyl growth, also under warm temperature conditions, and protein-protein interaction studies revealed possible interactors of SLOMO, such as MKK5, DWF1, and NCED4. We identified DWF1 as a likely SLOMO substrate and a regulator of warm temperature-mediated hypocotyl growth. We propose that warm temperature-mediated regulation of SLOMO activity controls the abundance of hypocotyl growth regulators, such as DWF1, through ubiquitin-mediated degradation.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas F-Box , Arabidopsis/metabolismo , Hipocótilo/metabolismo , Proteínas de Arabidopsis/metabolismo , Temperatura , Proteínas F-Box/metabolismo , Regulação da Expressão Gênica de Plantas
7.
Plant Cell ; 33(4): 794-813, 2021 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-33823021

RESUMO

Clustered regularly interspaced short palindromic repeat (CRISPR)-associated systems have revolutionized genome engineering by facilitating a wide range of targeted DNA perturbations. These systems have resulted in the development of powerful new screens to test gene functions at the genomic scale. While there is tremendous potential to map and interrogate gene regulatory networks at unprecedented speed and scale using CRISPR screens, their implementation in plants remains in its infancy. Here we discuss the general concepts, tools, and workflows for establishing CRISPR screens in plants and analyze the handful of recent reports describing the use of this strategy to generate mutant knockout collections or to diversify DNA sequences. In addition, we provide insight into how to design CRISPR knockout screens in plants given the current challenges and limitations and examine multiple design options. Finally, we discuss the unique multiplexing capabilities of CRISPR screens to investigate redundant gene functions in highly duplicated plant genomes. Combinatorial mutant screens have the potential to routinely generate higher-order mutant collections and facilitate the characterization of gene networks. By integrating this approach with the numerous genomic profiles that have been generated over the past two decades, the implementation of CRISPR screens offers new opportunities to analyze plant genomes at deeper resolution and will lead to great advances in functional and synthetic biology.


Assuntos
Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Edição de Genes/métodos , Plantas/genética , Sistemas CRISPR-Cas , Técnicas de Inativação de Genes/métodos , Ensaios de Triagem em Larga Escala/métodos , Mutação , Plantas Geneticamente Modificadas , Densidade Demográfica , RNA Guia de Cinetoplastídeos
8.
Nature ; 563(7732): 574-578, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30429609

RESUMO

Stomatal cell lineage is an archetypal example of asymmetric cell division (ACD), which is necessary for plant survival1-4. In Arabidopsis thaliana, the GLYCOGEN SYNTHASE KINASE3 (GSK3)/SHAGGY-like kinase BRASSINOSTEROID INSENSITIVE 2 (BIN2) phosphorylates both the mitogen-activated protein kinase (MAPK) signalling module5,6 and its downstream target, the transcription factor SPEECHLESS (SPCH)7, to promote and restrict ACDs, respectively, in the same stomatal lineage cell. However, the mechanisms that balance these mutually exclusive activities remain unclear. Here we identify the plant-specific protein POLAR as a stomatal lineage scaffold for a subset of GSK3-like kinases that confines them to the cytosol and subsequently transiently polarizes them within the cell, together with BREAKING OF ASYMMETRY IN THE STOMATAL LINEAGE (BASL), before ACD. As a result, MAPK signalling is attenuated, enabling SPCH to drive ACD in the nucleus. Moreover, POLAR turnover requires phosphorylation on specific residues, mediated by GSK3. Our study reveals a mechanism by which the scaffolding protein POLAR ensures GSK3 substrate specificity, and could serve as a paradigm for understanding regulation of GSK3 in plants.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/citologia , Arabidopsis/metabolismo , Divisão Celular Assimétrica , Proteínas de Ciclo Celular/metabolismo , Polaridade Celular , Complexos Multiproteicos/metabolismo , Transdução de Sinais , Arabidopsis/enzimologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Linhagem da Célula , Citosol/enzimologia , Citosol/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Sistema de Sinalização das MAP Quinases , Complexos Multiproteicos/química , Fenótipo , Fosforilação , Estômatos de Plantas/citologia , Ligação Proteica , Proteínas Quinases/metabolismo , Especificidade por Substrato
9.
Proc Natl Acad Sci U S A ; 118(2)2021 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-33443212

RESUMO

Agrobacterium spp. are important plant pathogens that are the causative agents of crown gall or hairy root disease. Their unique infection strategy depends on the delivery of part of their DNA to plant cells. Thanks to this capacity, these phytopathogens became a powerful and indispensable tool for plant genetic engineering and agricultural biotechnology. Although Agrobacterium spp. are standard tools for plant molecular biologists, current laboratory strains have remained unchanged for decades and functional gene analysis of Agrobacterium has been hampered by time-consuming mutation strategies. Here, we developed clustered regularly interspaced short palindromic repeats (CRISPR)-mediated base editing to enable the efficient introduction of targeted point mutations into the genomes of both Agrobacterium tumefaciens and Agrobacterium rhizogenes As an example, we generated EHA105 strains with loss-of-function mutations in recA, which were fully functional for maize (Zea mays) transformation and confirmed the importance of RolB and RolC for hairy root development by A. rhizogenes K599. Our method is highly effective in 9 of 10 colonies after transformation, with edits in at least 80% of the cells. The genomes of EHA105 and K599 were resequenced, and genome-wide off-target analysis was applied to investigate the edited strains after curing of the base editor plasmid. The off-targets present were characteristic of Cas9-independent off-targeting and point to TC motifs as activity hotspots of the cytidine deaminase used. We anticipate that CRISPR-mediated base editing is the start of "engineering the engineer," leading to improved Agrobacterium strains for more efficient plant transformation and gene editing.


Assuntos
Agrobacterium/genética , Proteínas Associadas a CRISPR/genética , Edição de Genes/métodos , Agrobacterium tumefaciens/genética , Proteínas Associadas a CRISPR/metabolismo , Sistemas CRISPR-Cas/genética , Sistemas CRISPR-Cas/fisiologia , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , DNA de Plantas/genética , Genes de Plantas/genética , Genoma de Planta/genética , Mutagênese/genética , Mutação/genética , Zea mays/genética
10.
Eur J Immunol ; 52(2): 312-327, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34752634

RESUMO

Overwhelming activation of T cells in acute malaria is associated with severe outcomes. Thus, counter-regulation by anti-inflammatory mechanisms is indispensable for an optimal resolution of disease. Using Plasmodium berghei ANKA (PbA) infection of C57BL/6 mice, we performed a comprehensive analysis of co-inhibitory molecules expressed on CD4+ and CD8+ T cells using an unbiased cluster analysis approach. We identified similar T cell clusters co-expressing several co-inhibitory molecules like programmed cell death protein 1 (PD-1) and lymphocyte activation gene 3 (LAG-3) in the CD4+ and the CD8+ T cell compartment. Interestingly, despite expressing co-inhibitory molecules, which are associated with T cell exhaustion in chronic settings, these T cells were more functional compared to activated T cells that were negative for co-inhibitory molecules. However, T cells expressing high levels of PD-1 and LAG-3 also conferred suppressive capacity and thus resembled type I regulatory T cells. To our knowledge, this is the first description of malaria-induced CD8+ T cells with suppressive capacity. Importantly, we found an induction of T cells with a similar co-inhibitory rich phenotype in Plasmodium falciparum-infected patients. In conclusion, we demonstrate that malaria-induced T cells expressing co-inhibitory molecules are not exhausted, but acquire additional suppressive capacity, which might represent an immune regulatory pathway to prevent further activation of T cells during acute malaria.


Assuntos
Antígenos CD/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Regulação da Expressão Gênica/imunologia , Tolerância Imunológica , Malária Falciparum/imunologia , Plasmodium berghei/imunologia , Plasmodium falciparum/imunologia , Receptor de Morte Celular Programada 1/imunologia , Adolescente , Adulto , Animais , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Proteína do Gene 3 de Ativação de Linfócitos
11.
Cytometry A ; 103(8): 624-630, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37219006

RESUMO

This 41-color panel has been designed to characterize both the lymphoid and the myeloid compartments in mice. The number of immune cells isolated from organs is often low, whilst an increasing number of factors need to be analyzed to gain a deeper understanding of the complexity of an immune response. With a focus on T cells, their activation and differentiation status, as well as their expression of several co-inhibitory and effector molecules, this panel also allows the analysis of ligands to these co-inhibitory molecules on antigen-presenting cells. This panel enables deep phenotypic characterization of CD4+ and CD8+ T cells, regulatory T cells, γδ T cells, NK T cells, B cells, NK cells, monocytes, macrophages, dendritic cells, and neutrophils. Whilst previous panels have focused on these topics individually, this is the first panel to enable simultaneous analysis of these compartments, thus enabling a comprehensive analysis with a limited number of immune cells/sample size. This panel is designed to analyze and compare the immune response in different mouse models of infectious diseases, but can also be extended to other disease models, for example tumors or autoimmune diseases. Here, we apply this panel to C57BL/6 mice infected with Plasmodium berghei ANKA, a mouse model of cerebral malaria.


Assuntos
Células Apresentadoras de Antígenos , Linfócitos T CD8-Positivos , Animais , Camundongos , Ligantes , Camundongos Endogâmicos C57BL , Monócitos
12.
New Phytol ; 239(4): 1521-1532, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37306056

RESUMO

A major advantage of using CRISPR/Cas9 for gene editing is multiplexing, that is, the simultaneous targeting of many genes. However, primary transformants typically contain hetero-allelic mutations or are genetic mosaic, while genetically stable lines that are homozygous are desired for functional analysis. Currently, a dedicated and labor-intensive effort is required to obtain such higher-order mutants through several generations of genetic crosses and genotyping. We describe the design and validation of a rapid and efficient strategy to produce lines of genetically identical plants carrying various combinations of homozygous edits, suitable for replicated analysis of phenotypical differences. This approach was achieved by combining highly multiplex gene editing in Zea mays (maize) with in vivo haploid induction and efficient in vitro generation of doubled haploid plants using embryo rescue doubling. By combining three CRISPR/Cas9 constructs that target in total 36 genes potentially involved in leaf growth, we generated an array of homozygous lines with various combinations of edits within three generations. Several genotypes show a reproducible 10% increase in leaf size, including a septuple mutant combination. We anticipate that our strategy will facilitate the study of gene families via multiplex CRISPR mutagenesis and the identification of allele combinations to improve quantitative crop traits.


Assuntos
Edição de Genes , Zea mays , Zea mays/genética , Sistemas CRISPR-Cas/genética , Genoma de Planta , Haploidia , Plantas Geneticamente Modificadas
13.
Plant Cell ; 2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32843437

RESUMO

CRISPR-Cas systems have revolutionized genome engineering by facilitating a wide range of targeted DNA perturbations. These systems have resulted in new powerful screens to test gene functions at the genomic scale. While there is tremendous potential for CRISPR screens to map and interrogate gene regulatory networks at unprecedented speed and scale, their implementation in plants remains in its infancy. Here we discuss the general concepts, tools and workflows for establishing CRISPR screens in plants and analyze the handful of recent reports using this strategy to generate mutant knockout collections or diversify DNA sequences. In addition, we provide insight on how to design CRISPR knockout screens in plants given the current challenges and limitations and examine multiple design options. Finally, we discuss the unique multiplexing capabilities of CRISPR screens to investigate redundant gene function in highly duplicated plant genomes. Combinatorial mutant screens have the potential to routinely generate higher-order mutant collections and facilitate the characterization of gene networks. By integrating this approach with the large resource of genomic profiles that were generated in the last two decades, the implementation of CRISPR screens offers new opportunities to analyze plant genomes at deeper resolution and will greatly advance plant functional and synthetic biology.

14.
J Phycol ; 59(3): 433-440, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37256696

RESUMO

Green seaweeds exhibit a wide range of morphologies and occupy various ecological niches, spanning from freshwater to marine and terrestrial habitats. These organisms, which predominantly belong to the class Ulvophyceae, showcase a remarkable instance of parallel evolution toward complex multicellularity and macroscopic thalli in the Viridiplantae lineage. Within the green seaweeds, several Ulva species ("sea lettuce") are model organisms for studying carbon assimilation, interactions with bacteria, life cycle progression, and morphogenesis. Ulva species are also notorious for their fast growth and capacity to dominate nutrient-rich, anthropogenically disturbed coastal ecosystems during "green tide" blooms. From an economic perspective, Ulva has garnered increasing attention as a promising feedstock for the production of food, feed, and biobased products, also as a means of removing excess nutrients from the environment. We propose that Ulva is poised to further develop as a model in green seaweed research. In this perspective, we focus explicitly on Ulva mutabilis/compressa as a model species and highlight the molecular data and tools that are currently available or in development. We discuss several areas that will benefit from future research or where exciting new developments have been reported in other Ulva species.


Assuntos
Clorófitas , Alga Marinha , Ulva , Ecossistema , Biologia de Sistemas
15.
BMC Plant Biol ; 22(1): 142, 2022 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-35331142

RESUMO

BACKGROUND: Precision genome mutagenesis using CRISPR/Cas has become the standard method to generate mutant plant lines. Several improvements have been made to increase mutagenesis efficiency, either through vector optimisation or the application of heat stress. RESULTS: Here, we present a simplified heat stress assay that can be completed in six days using commonly-available laboratory equipment. We show that three heat shocks (3xHS) efficiently increases indel efficiency of LbCas12a and Cas9, irrespective of the target sequence or the promoter used to express the nuclease. The generated indels are primarily somatic, but for three out of five targets we demonstrate that up to 25% more biallelic mutations are transmitted to the progeny when heat is applied compared to non-heat controls. We also applied our heat treatment to lines containing CRISPR base editors and observed a 22-27% increase in the percentage of C-to-T base editing. Furthermore, we test the effect of 3xHS on generating large deletions and a homologous recombination reporter. Interestingly, we observed no positive effect of 3xHS treatment on either approach using our conditions. CONCLUSIONS: Together, our experiments show that heat treatment is consistently effective at increasing the number of somatic mutations using many CRISPR approaches in plants and in some cases can increase the recovery of mutant progeny.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Edição de Genes/métodos , Genoma de Planta/genética , Mutagênese , Plantas Geneticamente Modificadas/genética
16.
Clin Exp Immunol ; 207(2): 227-236, 2022 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-35020841

RESUMO

Relatively little is known about the ex vivo frequency and phenotype of the Plasmodium falciparum-specific CD4+ T-cell response in humans. The exported protein 1 (EXP1) is expressed by plasmodia at both, the liver stage and blood stage, of infection making it a potential target for CD4+ and CD8+ effector T cells. Here, a fluorochrome-labelled HLA-DRB1∗11:01-restriced MHC class II tetramer derived from the P. falciparum EXP1 (aa62-74) was established for ex vivo tetramer analysis and magnetic bead enrichment in 10 patients with acute malaria. EXP1-specific CD4+ T cells were detectable in 9 out of 10 (90%) malaria patients expressing the HLA-DRB1∗11 molecule with an average ex vivo frequency of 0.11% (0-0.22%) of total CD4+ T cells. The phenotype of EXP1-specific CD4+ T cells was further assessed using co-staining with activation (CD38, HLA-DR, CD26), differentiation (CD45RO, CCR7, KLRG1, CD127), senescence (CD57), and co-inhibitory (PD-1, TIGIT, LAG-3, TIM-3) markers as well as the ectonucleotidases CD39 and CD73. EXP1-specific tetramer+ CD4+ T cells had a distinct phenotype compared to bulk CD4+ T cells and displayed a highly activated effector memory phenotype with elevated levels of co-inhibitory receptors and activation markers: EXP1-specific CD4+ T cells universally expressed the co-inhibitory receptors PD-1 and TIGIT as well as the activation marker CD38 and showed elevated frequencies of CD39. These results demonstrate that MHC class II tetramer enrichment is a sensitive approach to investigate ex vivo antigen-specific CD4+ T cells in malaria patients that will aid further analysis of the role of CD4+ T cells during malaria.


Assuntos
Linfócitos T CD4-Positivos , Malária Falciparum , Linfócitos T CD4-Positivos/metabolismo , Subtipos Sorológicos de HLA-DR , Humanos , Plasmodium falciparum , Receptor de Morte Celular Programada 1/metabolismo , Receptores Imunológicos/metabolismo
17.
New Phytol ; 233(1): 329-343, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34637542

RESUMO

Advanced transcriptome sequencing has revealed that the majority of eukaryotic genes undergo alternative splicing (AS). Nonetheless, little effort has been dedicated to investigating the functional relevance of particular splicing events, even those in the key developmental and hormonal regulators. Combining approaches of genetics, biochemistry and advanced confocal microscopy, we describe the impact of alternative splicing on the PIN7 gene in the model plant Arabidopsis thaliana. PIN7 encodes a polarly localized transporter for the phytohormone auxin and produces two evolutionarily conserved transcripts, PIN7a and PIN7b. PIN7a and PIN7b, differing in a four amino acid stretch, exhibit almost identical expression patterns and subcellular localization. We reveal that they are closely associated and mutually influence each other's mobility within the plasma membrane. Phenotypic complementation tests indicate that the functional contribution of PIN7b per se is minor, but it markedly reduces the prominent PIN7a activity, which is required for correct seedling apical hook formation and auxin-mediated tropic responses. Our results establish alternative splicing of the PIN family as a conserved, functionally relevant mechanism, revealing an additional regulatory level of auxin-mediated plant development.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Transporte Biológico , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos , Raízes de Plantas/metabolismo , Isoformas de Proteínas/genética
18.
Plant Physiol ; 186(3): 1442-1454, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-33905515

RESUMO

The green seaweed Ulva mutabilis is an ecologically important marine primary producer as well as a promising cash crop cultivated for multiple uses. Despite its importance, several molecular tools are still needed to better understand seaweed biology. Here, we report the development of a flexible and modular molecular cloning toolkit for the green seaweed U. mutabilis based on a Golden Gate cloning system. The toolkit presently contains 125 entry vectors, 26 destination vectors, and 107 functionally validated expression vectors. We demonstrate the importance of endogenous regulatory sequences for transgene expression and characterize three endogenous promoters suitable to drive transgene expression. We describe two vector architectures to express transgenes via two expression cassettes or a bicistronic approach. The majority of selected transformants (50%-80%) consistently give clear visual transgene expression. Furthermore, we made different marker lines for intracellular compartments after evaluating 13 transit peptides and 11 tagged endogenous Ulva genes. Our molecular toolkit enables the study of Ulva gain-of-function lines and paves the way for gene characterization and large-scale functional genomics studies in a green seaweed.


Assuntos
Clorófitas/genética , Clonagem Molecular/métodos , Produtos Agrícolas/genética , Alga Marinha/genética , Ulva/genética , Oceano Atlântico , Genes de Plantas , Portugal
19.
Plant Cell ; 31(12): 2868-2887, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31562216

RESUMO

Detailed functional analyses of many fundamentally important plant genes via conventional loss-of-function approaches are impeded by the severe pleiotropic phenotypes resulting from these losses. In particular, mutations in genes that are required for basic cellular functions and/or reproduction often interfere with the generation of homozygous mutant plants, precluding further functional studies. To overcome this limitation, we devised a clustered regularly interspaced short palindromic repeats (CRISPR)-based tissue-specific knockout system, CRISPR-TSKO, enabling the generation of somatic mutations in particular plant cell types, tissues, and organs. In Arabidopsis (Arabidopsis thaliana), CRISPR-TSKO mutations in essential genes caused well-defined, localized phenotypes in the root cap, stomatal lineage, or entire lateral roots. The modular cloning system developed in this study allows for the efficient selection, identification, and functional analysis of mutant lines directly in the first transgenic generation. The efficacy of CRISPR-TSKO opens avenues for discovering and analyzing gene functions in the spatial and temporal contexts of plant life while avoiding the pleiotropic effects of system-wide losses of gene function.


Assuntos
Arabidopsis/genética , Sistemas CRISPR-Cas/genética , Clonagem Molecular/métodos , Técnicas de Inativação de Genes/métodos , Mutagênese , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Quinases Ciclina-Dependentes/genética , Quinases Ciclina-Dependentes/metabolismo , Vetores Genéticos , Especificidade de Órgãos/genética , Fenótipo , Coifa/genética , Raízes de Plantas/genética , Estômatos de Plantas/genética , Regiões Promotoras Genéticas
20.
J Infect Dis ; 221(7): 1098-1106, 2020 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-31701142

RESUMO

BACKGROUND: Malaria presents with unspecific clinical symptoms that frequently overlap with other infectious diseases and is also a risk factor for coinfections, such as non-Typhi Salmonella. Malaria rapid diagnostic tests are sensitive but unable to distinguish between an acute infection requiring treatment and asymptomatic malaria with a concomitant infection. We set out to test whether cytokine profiles could predict disease status and allow the differentiation between malaria and a bacterial bloodstream infection. METHODS: We created a classification model based on cytokine concentration levels of pediatric inpatients with either Plasmodium falciparum malaria or a bacterial bloodstream infection using the Luminex platform. Candidate markers were preselected using classification and regression trees, and the predictive strength was calculated through random forest modeling. RESULTS: Analyses revealed that a combination of 7-15 cytokines exhibited a median disease prediction accuracy of 88% (95th percentile interval, 73%-100%). Haptoglobin, soluble Fas-Ligand, and complement component C2 were the strongest single markers with median prediction accuracies of 82% (with 95th percentile intervals of 71%-94%, 62%-94%, and 62%-94%, respectively). CONCLUSIONS: Cytokine profiles possess good median disease prediction accuracy and offer new possibilities for the development of innovative point-of-care tests to guide treatment decisions in malaria-endemic regions.


Assuntos
Bacteriemia/diagnóstico , Citocinas/sangue , Malária Falciparum/diagnóstico , Parasitemia/diagnóstico , Bacteriemia/epidemiologia , Bacteriemia/metabolismo , Biomarcadores/sangue , Estudos de Casos e Controles , Pré-Escolar , Diagnóstico Diferencial , Feminino , Humanos , Lactente , Malária Falciparum/epidemiologia , Malária Falciparum/metabolismo , Masculino , Parasitemia/epidemiologia , Parasitemia/metabolismo
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