Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 3.083
Filtrar
Más filtros

Publication year range
1.
Cell ; 183(2): 347-362.e24, 2020 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-33064988

RESUMEN

Neoantigens arise from mutations in cancer cells and are important targets of T cell-mediated anti-tumor immunity. Here, we report the first open-label, phase Ib clinical trial of a personalized neoantigen-based vaccine, NEO-PV-01, in combination with PD-1 blockade in patients with advanced melanoma, non-small cell lung cancer, or bladder cancer. This analysis of 82 patients demonstrated that the regimen was safe, with no treatment-related serious adverse events observed. De novo neoantigen-specific CD4+ and CD8+ T cell responses were observed post-vaccination in all of the patients. The vaccine-induced T cells had a cytotoxic phenotype and were capable of trafficking to the tumor and mediating cell killing. In addition, epitope spread to neoantigens not included in the vaccine was detected post-vaccination. These data support the safety and immunogenicity of this regimen in patients with advanced solid tumors (Clinicaltrials.gov: NCT02897765).


Asunto(s)
Vacunas contra el Cáncer/inmunología , Inmunoterapia/métodos , Medicina de Precisión/métodos , Anciano , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/inmunología , Linfocitos T CD8-positivos/inmunología , Vacunas contra el Cáncer/genética , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/inmunología , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Melanoma/tratamiento farmacológico , Melanoma/inmunología , Persona de Mediana Edad , Mutación , Nivolumab/uso terapéutico , Receptor de Muerte Celular Programada 1/inmunología , Receptor de Muerte Celular Programada 1/metabolismo , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Neoplasias de la Vejiga Urinaria/inmunología
2.
Cell ; 176(1-2): 295-305.e10, 2019 01 10.
Artículo en Inglés | MEDLINE | ID: mdl-30528431

RESUMEN

Between 5,000 and 6,000 years ago, many Neolithic societies declined throughout western Eurasia due to a combination of factors that are still largely debated. Here, we report the discovery and genome reconstruction of Yersinia pestis, the etiological agent of plague, in Neolithic farmers in Sweden, pre-dating and basal to all modern and ancient known strains of this pathogen. We investigated the history of this strain by combining phylogenetic and molecular clock analyses of the bacterial genome, detailed archaeological information, and genomic analyses from infected individuals and hundreds of ancient human samples across Eurasia. These analyses revealed that multiple and independent lineages of Y. pestis branched and expanded across Eurasia during the Neolithic decline, spreading most likely through early trade networks rather than massive human migrations. Our results are consistent with the existence of a prehistoric plague pandemic that likely contributed to the decay of Neolithic populations in Europe.


Asunto(s)
Peste/historia , Yersinia pestis/clasificación , Yersinia pestis/patogenicidad , Evolución Biológica , ADN Bacteriano/genética , Europa (Continente) , Genoma Bacteriano , Historia Antigua , Humanos , Pandemias , Filogenia
3.
Cell ; 168(1-2): 186-199.e12, 2017 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-28041851

RESUMEN

Bacteriophages (phages) typically exhibit a narrow host range, yet they tremendously impact horizontal gene transfer (HGT). Here, we investigate phage dynamics in communities harboring phage-resistant (R) and sensitive (S) bacteria, a common scenario in nature. Using Bacillus subtilis and its lytic phage SPP1, we demonstrate that R cells, lacking SPP1 receptor, can be lysed by SPP1 when co-cultured with S cells. This unanticipated lysis was triggered in part by phage lytic enzymes released from nearby infected cells. Strikingly, we discovered that occasionally phages can invade R cells, a phenomenon we termed acquisition of sensitivity (ASEN). We found that ASEN is mediated by R cells transiently gaining phage attachment molecules from neighboring S cells and provide evidence that this molecular exchange is driven by membrane vesicles. Exchange of phage attachment molecules could even occur in an interspecies fashion, enabling phage adsorption to non-host species, providing an unexplored route for HGT. VIDEO ABSTRACT.


Asunto(s)
Fagos de Bacillus/fisiología , Bacillus subtilis/virología , Bacteriólisis , Receptores Virales/metabolismo , Bacillus/virología , Fagos de Bacillus/enzimología , Bacillus subtilis/metabolismo , Especificidad del Huésped , Staphylococcus aureus/virología , Transducción Genética
4.
Cell ; 167(3): 670-683.e10, 2016 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-27768890

RESUMEN

Spotted fever group (SFG) rickettsiae are human pathogens that infect cells in the vasculature. They disseminate through host tissues by a process of cell-to-cell spread that involves protrusion formation, engulfment, and vacuolar escape. Other bacterial pathogens rely on actin-based motility to provide a physical force for spread. Here, we show that SFG species Rickettsia parkeri typically lack actin tails during spread and instead manipulate host intercellular tension and mechanotransduction to promote spread. Using transposon mutagenesis, we identified surface cell antigen 4 (Sca4) as a secreted effector of spread that specifically promotes protrusion engulfment. Sca4 interacts with the cell-adhesion protein vinculin and blocks association with vinculin's binding partner, α-catenin. Using traction and monolayer stress microscopy, we show that Sca4 reduces vinculin-dependent mechanotransduction at cell-cell junctions. Our results suggest that Sca4 relieves intercellular tension to promote protrusion engulfment, which represents a distinctive strategy for manipulating cytoskeletal force generation to enable spread.


Asunto(s)
Antígenos Bacterianos/metabolismo , Proteínas Bacterianas/metabolismo , Interacciones Huésped-Patógeno , Mecanotransducción Celular , Infecciones por Rickettsia/metabolismo , Infecciones por Rickettsia/microbiología , Rickettsia/patogenicidad , Vinculina/metabolismo , Actinas/metabolismo , Secuencia de Aminoácidos , Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Cadherinas/metabolismo , Adhesión Celular , Línea Celular Tumoral , Elementos Transponibles de ADN/genética , Fiebre/metabolismo , Fiebre/microbiología , Humanos , Mutagénesis Insercional , Mutación , Rickettsia/metabolismo , alfa Catenina/metabolismo
5.
Proc Natl Acad Sci U S A ; 120(1): e2201911120, 2023 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-36574645

RESUMEN

Our ability to predict the spread of alien species is largely based on knowledge of previous invasion dynamics of individual species. However, in view of the large and growing number of alien species, understanding universal spread patterns common among taxa but specific to regions would considerably improve our ability to predict future dynamics of biological invasions. Here, using a comprehensive dataset of years of first record of alien species for four major biological groups (birds, nonmarine fishes, insects, and vascular plants), we applied a network approach to uncover frequent sequential patterns of first recordings of alien species across countries worldwide. Our analysis identified a few countries as consistent early recorders of alien species, with many subsequent records reported from countries in close geographic vicinity. These findings indicate that the spread network of alien species consists of two levels, a backbone of main dispersal hubs, driving intercontinental species movement, and subsequent intracontinental radiative spread in their vicinity. Geographical proximity and climatic similarity were significant predictors of same-species recording among countries. International trade was a significant predictor of the relative timing of species recordings, with countries having higher levels of trade flows consistently recording the species earlier. Targeting the countries that have emerged as hubs for the early spread of alien species may have substantial cascading effects on the global spread network of alien species, significantly reducing biological invasions. Furthermore, using these countries as early-warning system of upcoming invasions may also boost national prevention and invasion preparedness efforts.


Asunto(s)
Especies Introducidas , Tracheophyta , Animales , Comercio , Internacionalidad , Aves
6.
Proc Natl Acad Sci U S A ; 120(16): e2216948120, 2023 04 18.
Artículo en Inglés | MEDLINE | ID: mdl-37036987

RESUMEN

Indoor superspreading events are significant drivers of transmission of respiratory diseases. In this work, we study the dynamics of airborne transmission in consecutive meetings of individuals in enclosed spaces. In contrast to the usual pairwise-interaction models of infection where effective contacts transmit the disease, we focus on group interactions where individuals with distinct health states meet simultaneously. Specifically, the disease is transmitted by infected individuals exhaling droplets (contributing to the viral load in the closed space) and susceptible ones inhaling the contaminated air. We propose a modeling framework that couples the fast dynamics of the viral load attained over meetings in enclosed spaces and the slow dynamics of disease progression at the population level. Our modeling framework incorporates the multiple time scales involved in different setups in which indoor events may happen, from single-time events to events hosting multiple meetings per day, over many days. We present theoretical and numerical results of trade-offs between the room characteristics (ventilation system efficiency and air mass) and the group's behavioral and composition characteristics (group size, mask compliance, testing, meeting time, and break times), that inform indoor policies to achieve disease control in closed environments through different pathways. Our results emphasize the impact of break times, mask-wearing, and testing on facilitating the conditions to achieve disease control. We study scenarios of different break times, mask compliance, and testing. We also derive policy guidelines to contain the infection rate under a certain threshold.


Asunto(s)
Contaminación del Aire Interior , Contaminación del Aire , Humanos
7.
J Virol ; 98(5): e0198623, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38619272

RESUMEN

Human cytomegalovirus (hCMV) is a ubiquitous facultative pathogen, which establishes a characteristic latent and reactivating lifelong infection in immunocompetent hosts. Murine CMV (mCMV) infection is widely used as an experimental model of hCMV infection, employed to investigate the causal nature and extent of CMV's contribution to inflammatory, immunological, and health disturbances in humans. Therefore, mimicking natural human infection in mice would be advantageous to hCMV research. To assess the role of route and age at infection in modeling hCMV in mice, we infected prepubescent and young sexually mature C57BL/6 (B6) mice intranasally (i.n., a likely physiological route in humans) and intraperitoneally (i.p., a frequently used experimental route, possibly akin to transplant-mediated infection). In our hands, both routes led to comparable early viral loads and tissue spreads. However, they yielded differential profiles of innate and adaptive systemic immune activation. Specifically, the younger, prepubescent mice exhibited the strongest natural killer cell activation in the blood in response to i.p. infection. Further, the i.p. infected animals (particularly those infected at 12 weeks) exhibited larger anti-mCMV IgG and greater expansion of circulating CD8+ T cells specific for both acute (non-inflationary) and latent phase (inflationary) mCMV epitopes. By contrast, tissue immune responses were comparable between i.n. and i.p. groups. Our results illustrate a distinction in the bloodborne immune response profiles across infection routes and ages and are discussed in light of physiological parameters of interaction between CMV, immunity, inflammation, and health over the lifespan. IMPORTANCE: The majority of experiments modeling human cytomegalovirus (hCMV) infection in mice have been carried out using intraperitoneal infection in sexually mature adult mice, which stands in contrast to the large number of humans being infected with human CMV at a young age, most likely via bodily fluids through the nasopharyngeal/oral route. This study examined the impact of the choice of age and route of infection in modeling CMV infection in mice. By comparing young, prepubescent to older sexually mature counterparts, infected either via the intranasal or intraperitoneal route, we discovered substantial differences in deployment and response intensity of different arms of the immune system in systemic control of the virus; tissue responses, by contrast, appeared similar between ages and infection routes.


Asunto(s)
Inmunidad Adaptativa , Infecciones por Citomegalovirus , Inmunidad Innata , Muromegalovirus , Animales , Femenino , Humanos , Ratones , Factores de Edad , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Infecciones por Citomegalovirus/inmunología , Infecciones por Citomegalovirus/virología , Modelos Animales de Enfermedad , Infecciones por Herpesviridae/inmunología , Infecciones por Herpesviridae/virología , Células Asesinas Naturales/inmunología , Ratones Endogámicos C57BL , Muromegalovirus/inmunología , Carga Viral
8.
J Virol ; 98(3): e0140123, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38358287

RESUMEN

Since 2020, clade 2.3.4.4b highly pathogenic avian influenza H5N8 and H5N1 viruses have swept through continents, posing serious threats to the world. Through comprehensive analyses of epidemiological, genetic, and bird migration data, we found that the dominant genotype replacement of the H5N8 viruses in 2020 contributed to the H5N1 outbreak in the 2021/2022 wave. The 2020 outbreak of the H5N8 G1 genotype instead of the G0 genotype produced reassortment opportunities and led to the emergence of a new H5N1 virus with G1's HA and MP genes. Despite extensive reassortments in the 2021/2022 wave, the H5N1 virus retained the HA and MP genes, causing a significant outbreak in Europe and North America. Furtherly, through the wild bird migration flyways investigation, we found that the temporal-spatial coincidence between the outbreak of the H5N8 G1 virus and the bird autumn migration may have expanded the H5 viral spread, which may be one of the main drivers of the emergence of the 2020-2022 H5 panzootic.IMPORTANCESince 2020, highly pathogenic avian influenza (HPAI) H5 subtype variants of clade 2.3.4.4b have spread across continents, posing unprecedented threats globally. However, the factors promoting the genesis and spread of H5 HPAI viruses remain unclear. Here, we found that the spatiotemporal genotype replacement of H5N8 HPAI viruses contributed to the emergence of the H5N1 variant that caused the 2021/2022 panzootic, and the viral evolution in poultry of Egypt and surrounding area and autumn bird migration from the Russia-Kazakhstan region to Europe are important drivers of the emergence of the 2020-2022 H5 panzootic. These findings provide important targets for early warning and could help control the current and future HPAI epidemics.


Asunto(s)
Subtipo H5N1 del Virus de la Influenza A , Subtipo H5N8 del Virus de la Influenza A , Gripe Aviar , Animales , Aves , Genotipo , Virus de la Influenza A/fisiología , Subtipo H5N1 del Virus de la Influenza A/genética , Subtipo H5N1 del Virus de la Influenza A/fisiología , Subtipo H5N8 del Virus de la Influenza A/genética , Subtipo H5N8 del Virus de la Influenza A/fisiología , Gripe Aviar/epidemiología , Gripe Aviar/virología , Filogenia , Aves de Corral
9.
J Virol ; 98(10): e0011924, 2024 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-39225467

RESUMEN

Between 2013 and 2018, the novel A/Anhui/1/2013 (AH/13)-lineage H7N9 virus caused at least five waves of outbreaks in humans, totaling 1,567 confirmed human cases in China. Surveillance data indicated a disproportionate distribution of poultry infected with this AH/13-lineage virus, and laboratory experiments demonstrated that this virus can efficiently spread among chickens but not among Pekin ducks. The underlying mechanism of this selective transmission remains unclear. In this study, we demonstrated the absence of Neu5Gc expression in chickens across all respiratory and gastrointestinal tissues. However, Neu5Gc expression varied among different duck species and even within the tissues of the same species. The AH/13-lineage viruses exclusively bind to acetylneuraminic acid (Neu5Ac), in contrast to wild waterbird H7 viruses that bind both Neu5Ac and N-glycolylneuraminic acid (Neu5Gc). The level of Neu5Gc expression influences H7 virus replication and facilitates adaptive mutations in these viruses. In summary, our findings highlight the critical role of Neu5Gc in affecting the host range and interspecies transmission dynamics of H7 viruses among avian species.IMPORTANCEMigratory waterfowl, gulls, and shorebirds are natural reservoirs for influenza A viruses (IAVs) that can occasionally spill over to domestic poultry, and ultimately humans. This study showed wild-type H7 IAVs from waterbirds initially bind to glycan receptors terminated with N-acetylneuraminic acid (Neu5Ac) or N-glycolylneuraminic acid (Neu5Gc). However, after enzootic transmission in chickens, the viruses exclusively bind to Neu5Ac. The absence of Neu5Gc expression in gallinaceous poultry, particularly chickens, exerts selective pressure, shaping IAV populations, and promoting the acquisition of adaptive amino acid substitutions in the hemagglutinin protein. This results in the loss of Neu5Gc binding and an increase in virus transmissibility in gallinaceous poultry, particularly chickens. Consequently, the transmission capability of these poultry-adapted H7 IAVs in wild water birds decreases. Timely intervention, such as stamping out, may help reduce virus adaptation to domestic chicken populations and lower the risk of enzootic outbreaks, including those caused by IAVs exhibiting high pathogenicity.


Asunto(s)
Pollos , Patos , Gripe Aviar , Ácidos Neuramínicos , Replicación Viral , Animales , Gripe Aviar/virología , Gripe Aviar/transmisión , Pollos/virología , Patos/virología , Ácidos Neuramínicos/metabolismo , Ácido N-Acetilneuramínico/metabolismo , Subtipo H7N9 del Virus de la Influenza A/genética , Subtipo H7N9 del Virus de la Influenza A/patogenicidad , China , Humanos , Glicoproteínas Hemaglutininas del Virus de la Influenza/metabolismo , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Enfermedades de las Aves de Corral/virología , Enfermedades de las Aves de Corral/transmisión , Enfermedades de las Aves de Corral/metabolismo , Aves de Corral/virología
10.
J Pathol ; 263(1): 113-127, 2024 05.
Artículo en Inglés | MEDLINE | ID: mdl-38482714

RESUMEN

The molecular mechanisms underpinning the development of metachronous tumors in the remnant bile duct following surgical resection of primary biliary tract carcinomas (BTCs) are unknown. This study aimed to elucidate these mechanisms by evaluating the clinicopathologic features of BTCs, the alterations to 31 BTC-related genes on targeted sequencing, and the aberrant expression of p53, p16, SMAD4, ARID1A and ß-catenin on immunohistochemistry. Twelve consecutive patients who underwent resection of metachronous BTCs following primary BTC resection with negative bile duct margins were enrolled. Among the 12 metachronous tumors, six exhibited anterograde growth in the lower portion and six exhibited retrograde growth in the upper portion of the biliary tree. Surgical resection of metachronous BTCs resulted in recurrence-free survival in seven, local recurrence in five, and death in two patients. Nine achieved 5-year overall survival after primary surgery. Molecular analyses revealed that recurrently altered genes were: TP53, SMAD4, CDKN2A, ELF3, ARID1A, GNAS, NF1, STK11, RNF43, KMT2D and ERBB3. Each of these was altered in at least three cases. A comparison of the molecular features between 12 paired primary and metachronous BTCs indicated that 10 (83%) metachronous tumors developed in clonal association with corresponding primary tumors either successionally or phylogenically. The remaining two (17%) developed distinctly. The successional tumors consisted of direct or evolved primary tumor clones that spread along the bile duct. The phylogenic tumors consisted of genetically unstable clones and conferred a poor prognosis. Metachronous tumors distinct from their primaries harbored fewer mutations than successional and phylogenic tumors. In conclusion, over 80% of metachronous BTCs that develop following primary BTC resection are probably molecularly associated with their primaries in either a successional or a phylogenetic manner. Comparison between the molecular features of a metachronous tumor and those of a preceding tumor may provide effective therapeutic clues for the treatment of metachronous BTC. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.


Asunto(s)
Neoplasias de los Conductos Biliares , Neoplasias del Sistema Biliar , Neoplasias Primarias Secundarias , Humanos , Neoplasias Primarias Secundarias/genética , Filogenia , Mutación , Conductos Biliares/patología , Neoplasias del Sistema Biliar/genética , Neoplasias del Sistema Biliar/patología , Neoplasias del Sistema Biliar/cirugía , Neoplasias de los Conductos Biliares/patología
11.
Drug Resist Updat ; 73: 101036, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38183874

RESUMEN

BACKGROUND: Extended-spectrum ß-lactamases (ESBLs) producing bacteria have spread worldwide and become a global public health concern. Plasmid-mediated transfer of ESBLs is an important route for resistance acquisition. METHODS: We collected 1345 complete sequences of plasmids containing CTX-Ms from public database. The global transmission pattern of plasmids and evolutionary dynamics of CTX-Ms have been inferred. We applied the pan-genome clustering based on plasmid genomes and evolution analysis to demonstrate the transmission events. FINDINGS: Totally, 48 CTX-Ms genotypes and 186 incompatible types of plasmids were identified. The geographical distribution of CTX-Ms showed significant differences across countries and continents. CTX-M-14 and CTX-M-55 were found to be the dominant genotypes in Asia, while CTX-M-1 played a leading role in Europe. The plasmids can be divided into 12 lineages, some of which forming distinct geographical clusters in Asia and Europe, while others forming hybrid populations. The Inc types of plasmids are lineage-specific, with the CTX-M-1_IncI1-I (Alpha) and CTX-M-65_IncFII (pHN7A8)/R being the dominant patterns of cross-host and cross-regional transmission. The IncI-I (Alpha) plasmids with the highest number, were presumed to form communication groups in Europe-Asia and Asia-America-Oceania, showing the transmission model as global dissemination and regional microevolution. Meanwhile, the main kinetic elements of blaCTX-Ms showed genotypic preferences. ISEcpl and IS26 were most frequently involved in the transfer of CTX-M-14 and CTX-M-65, respectively. IS15 has become a crucial participant in mediating the dissemination of blaCTX-Ms. Interestingly, blaTEM and blaCTX-Ms often coexisted in the same transposable unit. Furthermore, antibiotic resistance genes associated with aminoglycosides, sulfonamides and cephalosporins showed a relatively high frequency of synergistic effects with CTX-Ms. CONCLUSIONS: We recognized the dominant blaCTX-Ms and mainstream plasmids of different continents. The results of this study provide support for a more effective response to the risks associated with the evolution of blaCTX-Ms-bearing plasmids, and lay the foundation for genotype-specific epidemiological surveillance of resistance, which are of important public health implications.


Asunto(s)
Antibacterianos , Escherichia coli , Humanos , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , beta-Lactamasas/genética , Escherichia coli/genética , Genómica , Plásmidos/genética
12.
Proc Natl Acad Sci U S A ; 119(42): e2202871119, 2022 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-36215506

RESUMEN

COVID-19 is the latest zoonotic RNA virus epidemic of concern. Learning how it began and spread will help to determine how to reduce the risk of future events. We review major RNA virus outbreaks since 1967 to identify common features and opportunities to prevent emergence, including ancestral viral origins in birds, bats, and other mammals; animal reservoirs and intermediate hosts; and pathways for zoonotic spillover and community spread, leading to local, regional, or international outbreaks. The increasing scientific evidence concerning the origins of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is most consistent with a zoonotic origin and a spillover pathway from wildlife to people via wildlife farming and the wildlife trade. We apply what we know about these outbreaks to identify relevant, feasible, and implementable interventions. We identify three primary targets for pandemic prevention and preparedness: first, smart surveillance coupled with epidemiological risk assessment across wildlife-livestock-human (One Health) spillover interfaces; second, research to enhance pandemic preparedness and expedite development of vaccines and therapeutics; and third, strategies to reduce underlying drivers of spillover risk and spread and reduce the influence of misinformation. For all three, continued efforts to improve and integrate biosafety and biosecurity with the implementation of a One Health approach are essential. We discuss new models to address the challenges of creating an inclusive and effective governance structure, with the necessary stable funding for cross-disciplinary collaborative research. Finally, we offer recommendations for feasible actions to close the knowledge gaps across the One Health continuum and improve preparedness and response in the future.


Asunto(s)
COVID-19 , Quirópteros , Salud Única , Animales , Animales Salvajes , COVID-19/epidemiología , COVID-19/prevención & control , Humanos , Pandemias/prevención & control , SARS-CoV-2 , Zoonosis/epidemiología , Zoonosis/prevención & control
13.
Nano Lett ; 24(36): 11141-11148, 2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39214569

RESUMEN

Multicolor fluorescence microscopy is an essential tool to visualize structures and dynamics in the life and materials sciences. However, the near-simultaneous acquisition of labels differing in excitation spectrum is difficult and renders such measurements prone to artifacts. We present a simple strategy to provide quasi-simultaneous fluorescence imaging with multiple excitation wavelengths by using an optical element to displace the sample image on the sensor at a rate that is much faster than the image acquisition rate and synchronizing this with the illumination. The emission elicited by the different wavelengths can then be encoded into the point-spread function of the imaging or visualized as multiple distinct images. In doing so, our approach can eliminate or mitigate artifacts caused by temporal aliasing in conventional sequential imaging. We demonstrate the use of our system to uncover hidden emissive states in single quantum dots and for the imaging of Ca2+ signaling in neurons.

14.
Nano Lett ; 24(42): 13364-13373, 2024 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-39393017

RESUMEN

Three-dimensional (3D) imaging enables high-precision and high-resolution axial positioning, which is crucial for biological imaging, semiconductor defect monitoring, and other applications. Conventional implementations rely on bulky optical elements or scanning mechanisms, resulting in low speed and complicated setups. Here, we generate the double-helix (DH) point spread function with an all-dielectric metasurface and thus innovate the 3D imaging microscope (hence dubbed meta-microscope), both in 4f and 2f imaging systems. The 4f-meta-microscope with a numerical aperture of 0.7 achieves an axial localization accuracy below 0.12 µm within a 15.47 µm detection range, while the 2f-DH meta-microscope with a numerical aperture of 0.3 shows a 1.12 µm accuracy within a 227.33 µm range. We also demonstrate single-shot and accurate 3D biological imaging of the mouse kidney tissue and peach anther, providing a comprehensive and efficient approach for 3D bioimaging and other applications through a single-shot 3D meta-microscope.

15.
J Infect Dis ; 2024 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-39193849

RESUMEN

BACKGROUND: During the 2022 global mpox outbreak, the cumulative number of countries reporting their first imported case quickly rose in the early phase, but the importation rate subsequently slowed down, leaving many countries reporting no cases by the 2022 year-end. METHODS: We developed a mathematical model of international dissemination of mpox infections incorporating sexual networks and global mobility data. We used this model to characterize the mpox importation patterns observed in 2022 and to discuss the potential of further international spread. RESULTS: Our proposed model better explained the observed importation patterns than models not assuming heterogeneity in sexual contacts. Estimated importation hazards decreased in most countries, surpassing the global case count decline, suggesting a reduced per-case risk of importation. We assessed each country's potential to export mpox cases until the end of an epidemic, identifying countries capable of contributing to the future international spread. CONCLUSIONS: The accumulation of immunity among high-risk individuals over highly heterogeneous sexual networks may have contributed to the slowdown in the rate of mpox importations. Nevertheless, the existence of countries with the potential to contribute to the global spread of mpox highlights the importance of equitable resource access to prevent the global resurgence of mpox.

16.
Annu Rev Entomol ; 69: 355-373, 2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-37758223

RESUMEN

Global trade in fresh fruit and vegetables, intensification of human mobility, and climate change facilitate fruit fly (Diptera: Tephritidae) invasions. Life-history traits, environmental stress response, dispersal stress, and novel genetic admixtures contribute to their establishment and spread. Tephritids are among the most frequently intercepted taxa at ports of entry. In some countries, supported by the rules-based trade framework, a remarkable amount of biosecurity effort is being arrayed against the range expansion of tephritids. Despite this effort, fruit flies continue to arrive in new jurisdictions, sometimes triggering expensive eradication responses. Surprisingly, scant attention has been paid to biosecurity in the recent discourse about new multilateral trade agreements. Much of the available literature on managing tephritid invasions is focused on a limited number of charismatic (historically high-profile) species, and the generality of many patterns remains speculative.


Asunto(s)
Drosophila , Rasgos de la Historia de Vida , Animales , Humanos , Cambio Climático , Nonoxinol
17.
Infect Immun ; 92(9): e0052423, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-38661369

RESUMEN

For multiple intracellular bacterial pathogens, the ability to spread directly into adjacent epithelial cells is an essential step for disease in humans. For pathogens such as Shigella, Listeria, Rickettsia, and Burkholderia, this intercellular movement frequently requires the pathogens to manipulate the host actin cytoskeleton and deform the plasma membrane into structures known as protrusions, which extend into neighboring cells. The protrusion is then typically resolved into a double-membrane vacuole (DMV) from which the pathogen quickly escapes into the cytosol, where additional rounds of intercellular spread occur. Significant progress over the last few years has begun to define the mechanisms by which intracellular bacterial pathogens spread. This review highlights the interactions of bacterial and host factors that drive mechanisms required for intercellular spread with a focus on how protrusion structures form and resolve.


Asunto(s)
Interacciones Huésped-Patógeno , Humanos , Bacterias/patogenicidad , Bacterias/metabolismo , Animales , Células Epiteliales/microbiología , Infecciones Bacterianas/microbiología , Membrana Celular/metabolismo , Vacuolas/microbiología , Citoesqueleto de Actina/metabolismo
18.
Infect Immun ; 92(10): e0013624, 2024 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-39133017

RESUMEN

The food-borne pathogen Listeria monocytogenes uses actin-based motility to generate plasma membrane protrusions that mediate the spread of bacteria between host cells. In polarized epithelial cells, efficient protrusion formation by L. monocytogenes requires the secreted bacterial protein InlC, which binds to a carboxyl-terminal Src homology 3 (SH3) domain in the human scaffolding protein Tuba. This interaction antagonizes Tuba, thereby diminishing cortical tension at the apical junctional complex and enhancing L. monocytogenes protrusion formation and spread. Tuba contains five SH3 domains apart from the domain that interacts with InlC. Here, we show that human GTPase Dynamin 2 associates with two SH3 domains in the amino-terminus of Tuba and acts together with this scaffolding protein to control the spread of L. monocytogenes. Genetic or pharmacological inhibition of Dynamin 2 or knockdown of Tuba each restored normal protrusion formation and spread to a bacterial strain deleted for the inlC gene (∆inlC). Dynamin 2 localized to apical junctions in uninfected human cells and protrusions in cells infected with L. monocytogenes. Localization of Dynamin 2 to junctions and protrusions depended on Tuba. Knockdown of Dynamin 2 or Tuba diminished junctional linearity, indicating a role for these proteins in controlling cortical tension. Infection with L. monocytogenes induced InlC-dependent displacement of Dynamin 2 from junctions, suggesting a possible mechanism of antagonism of this GTPase. Collectively, our results show that Dynamin 2 cooperates with Tuba to promote intercellular tension that restricts the spread of ∆inlC Listeria. By expressing InlC, wild-type L. monocytogenes overcomes this restriction.


Asunto(s)
Proteínas Bacterianas , Dinamina II , Listeria monocytogenes , Listeria monocytogenes/metabolismo , Listeria monocytogenes/genética , Humanos , Dinamina II/metabolismo , Dinamina II/genética , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Listeriosis/microbiología , Listeriosis/metabolismo , Interacciones Huésped-Patógeno , Células Epiteliales/microbiología , Células Epiteliales/metabolismo , Uniones Intercelulares/metabolismo , Uniones Intercelulares/microbiología , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Dominios Homologos src
19.
Ecol Lett ; 27(1): e14345, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38069575

RESUMEN

Social systems vary enormously across the animal kingdom, with important implications for ecological and evolutionary processes such as infectious disease dynamics, anti-predator defence, and the evolution of cooperation. Comparing social network structures between species offers a promising route to help disentangle the ecological and evolutionary processes that shape this diversity. Comparative analyses of networks like these are challenging and have been used relatively little in ecology, but are becoming increasingly feasible as the number of empirical datasets expands. Here, we provide an overview of multispecies comparative social network studies in ecology and evolution. We identify a range of advancements that these studies have made and key challenges that they face, and we use these to guide methodological and empirical suggestions for future research. Overall, we hope to motivate wider publication and analysis of open social network datasets in animal ecology.


Asunto(s)
Ecología , Red Social , Animales
20.
Rep Prog Phys ; 87(3)2024 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-38373355

RESUMEN

HoloTile is a patented computer generated holography approach with the aim of reducing the speckle noise caused by the overlap of the non-trivial physical extent of the point spread function in Fourier holographic systems from adjacent frequency components. By combining tiling of phase-only of rapidly generated sub-holograms with a PSF-shaping phase profile, each frequency component-or output 'pixel'- in the Fourier domain is shaped to a desired non-overlapping profile. In this paper, we show the high-resolution, speckle-reduced reconstructions that can be achieved with HoloTile, as well as present new HoloTile modalities, including an expanded list of PSF options with new key properties. In addition, we discuss numerous applications for which HoloTile, its rapid hologram generation, and the new PSF options may be an ideal fit, including optical trapping and manipulation of particles, volumetric additive printing, information transfer and quantum communication.

SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda