Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 311
Filtrar
1.
Viruses ; 16(9)2024 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-39339826

RESUMEN

Anelloviruses are ubiquitous in humans and represent a major component of the human virome. Its best-known representative is Torque teno virus (i.e., the Alphatorquevirus genus), which is considered a potential immunity biomarker. Recent metagenomic investigations revealed not only the extraordinary genomic diversity of anellovirus sequences, but also that co-detection of genera, genotypes, or species seems to be the rule in humans. SCANellome was developed to represent a user-friendly tool to analyze the primate (both human and non-human) anellovirus composition at the genus, species, and genotype level from metagenomics data based on an up-to-date database. This SCANellome update includes >900 additional reference sequences from GenBank. Using a clustering at 90% identity, the FASTA database was updated and generated 134 new representative sequences. Based on ORF1, the analysis of these new sequences indicates the presence of 206 potential new species, including four nonhuman primates, and adds four new non-human primate species which will be the subject of a proposal to the International Committee on Taxonomy of Viruses (ICTV). In addition, SCANellome V2 provides now the user with an interactive up-to-date phylogenetic analysis (of ORF1) to show the distribution among the 12 human and nonhuman primate genera of these new potential species. Finally, the Anelloviridae taxonomy was updated to rename species names in binomial format as required by the ICTV.


Asunto(s)
Anelloviridae , Genoma Viral , Metagenómica , Filogenia , Primates , Animales , Primates/virología , Anelloviridae/genética , Anelloviridae/clasificación , Humanos , Metagenómica/métodos , Bases de Datos Genéticas , Genotipo , Sistemas de Lectura Abierta
2.
Rev Med Suisse ; 20(888): 1714-1717, 2024 Sep 25.
Artículo en Francés | MEDLINE | ID: mdl-39323274

RESUMEN

Community acquired pneumonia is a well-known entity in internal medicine. It represents 1.2 cases per 1000 inhabitants every year, and up to 14 cases per 100 inhabitants in people older than 65 years old. Despite our exposition to the disease almost daily, it is still the leading cause of death related to an infection. In 2019, The American Thoracic Society proposed a revision of its guidelines, especially concerning the diagnosis and the treatment of community acquired pneumonia. It is the latest academic society revision. Further-more, the SARS-CoV-2 pandemia has extended our knowledge of pulmonary infection and brought an adaptation of our practice.


La pneumonie acquise en communauté (PAC) est une entité bien connue de la médecine interne générale. En effet, elle représente 1,2 cas pour 1000 habitants chaque année, et jusqu'à 14 cas pour 1000 habitants chez les plus de 65 ans. Elle reste la première cause de mortalité liée à une infection et est responsable d'une morbidité importante. En 2019, l'American Thoracic Society propose une révision de ses guidelines, notamment sur le diagnostic et les traitements de la PAC. Il s'agit de la dernière revue de société savante. De plus, la pandémie de SARS-CoV-2 a enrichi notre compréhension des infections pulmonaires et a conduit à une adaptation de nos pratiques.


Asunto(s)
COVID-19 , Infecciones Comunitarias Adquiridas , Neumonía , Humanos , Infecciones Comunitarias Adquiridas/diagnóstico , Infecciones Comunitarias Adquiridas/terapia , Infecciones Comunitarias Adquiridas/epidemiología , COVID-19/diagnóstico , COVID-19/terapia , COVID-19/epidemiología , Neumonía/diagnóstico , Neumonía/terapia , Neumonía/epidemiología , Anciano , Guías de Práctica Clínica como Asunto , SARS-CoV-2
3.
Rev Med Suisse ; 20(869): 731-732, 2024 Apr 10.
Artículo en Francés | MEDLINE | ID: mdl-38616682
4.
Microbiol Spectr ; 12(5): e0362823, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38497714

RESUMEN

During the SARS-CoV-2 pandemic, many countries directed substantial resources toward genomic surveillance to detect and track viral variants. There is a debate over how much sequencing effort is necessary in national surveillance programs for SARS-CoV-2 and future pandemic threats. We aimed to investigate the effect of reduced sequencing on surveillance outcomes in a large genomic data set from Switzerland, comprising more than 143k sequences. We employed a uniform downsampling strategy using 100 iterations each to investigate the effects of fewer available sequences on the surveillance outcomes: (i) first detection of variants of concern (VOCs), (ii) speed of introduction of VOCs, (iii) diversity of lineages, (iv) first cluster detection of VOCs, (v) density of active clusters, and (vi) geographic spread of clusters. The impact of downsampling on VOC detection is disparate for the three VOC lineages, but many outcomes including introduction and cluster detection could be recapitulated even with only 35% of the original sequencing effort. The effect on the observed speed of introduction and first detection of clusters was more sensitive to reduced sequencing effort for some VOCs, in particular Omicron and Delta, respectively. A genomic surveillance program needs a balance between societal benefits and costs. While the overall national dynamics of the pandemic could be recapitulated by a reduced sequencing effort, the effect is strongly lineage-dependent-something that is unknown at the time of sequencing-and comes at the cost of accuracy, in particular for tracking the emergence of potential VOCs.IMPORTANCESwitzerland had one of the most comprehensive genomic surveillance systems during the COVID-19 pandemic. Such programs need to strike a balance between societal benefits and program costs. Our study aims to answer the question: How would surveillance outcomes have changed had we sequenced less? We find that some outcomes but also certain viral lineages are more affected than others by sequencing less. However, sequencing to around a third of the original effort still captured many important outcomes for the variants of concern such as their first detection but affected more strongly other measures like the detection of first transmission clusters for some lineages. Our work highlights the importance of setting predefined targets for a national genomic surveillance program based on which sequencing effort should be determined. Additionally, the use of a centralized surveillance platform facilitates aggregating data on a national level for rapid public health responses as well as post-analyses.


Asunto(s)
COVID-19 , Genoma Viral , SARS-CoV-2 , COVID-19/epidemiología , COVID-19/virología , COVID-19/diagnóstico , Humanos , SARS-CoV-2/genética , SARS-CoV-2/aislamiento & purificación , SARS-CoV-2/clasificación , Suiza/epidemiología , Genoma Viral/genética , Monitoreo Epidemiológico , Pandemias , Filogenia
5.
Microorganisms ; 12(2)2024 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-38399725

RESUMEN

During the SARS-CoV-2 pandemic, the Dr. Risch medical group employed the multiplex TaqPathTM COVID-19 CE-IVD RT-PCR Kit for large-scale routine diagnostic testing in Switzerland and the principality of Liechtenstein. The TaqPath Kit is a widely used multiplex assay targeting three genes (i.e., ORF1AB, N, S). With emergence of the B.1.1.7 (Alpha) variant, a diagnostic flaw became apparent as the amplification of the S-gene target was absent in these samples due to a deletion (ΔH69/V70) in the Alpha variant genome. This S-gene target failure (SGTF) was the earliest indication of a new variant emerging and was also observed in subsequent variants such as Omicron BA.1 and BA4/BA.5. The Delta variant and Omicron BA.2 did not present with SGTF. From September 2020 to November 2022, we investigated the applicability of the SGTF as a surrogate marker for emerging variants such as B.1.1.7, B.1.617.2 (Delta), and Omicron BA.1, BA.2, and BA.4/BA.5 in samples with cycle threshold (Ct) values < 30. Next to true SGTF-positive and SGTF-negative samples, there were also samples presenting with delayed-type S-gene amplification (higher Ct value for S-gene than ORF1ab gene). Among these, a difference of 3.8 Ct values between the S- and ORF1ab genes was found to best distinguish between "true" SGTF and the cycle threshold variability of the assay. Samples above the cutoff were subsequently termed partial SGTF (pSGTF). Variant confirmation was performed by whole-genome sequencing (Oxford Nanopore Technology, Oxford, UK) or mutation-specific PCR (TIB MOLBIOL). In total, 17,724 (7.4%) samples among 240,896 positives were variant-confirmed, resulting in an overall sensitivity and specificity of 93.2% [92.7%, 93.7%] and 99.3% [99.2%, 99.5%], respectively. Sensitivity was increased to 98.2% [97.9% to 98.4%] and specificity lowered to 98.9% [98.6% to 99.1%] when samples with pSGTF were included. Furthermore, weekly logistic growth rates (α) and sigmoid's midpoint (t0) were calculated based on SGTF data and did not significantly differ from calculations based on comprehensive data from GISAID. The SGTF therefore allowed for a valid real-time estimate for the introduction of all dominant variants in Switzerland and Liechtenstein.

7.
Clin Microbiol Infect ; 30(7): 883-887, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38387500

RESUMEN

BACKGROUND: Smallpox was a major cause of human mortality until its eradication, but the threat of orthopox viruses has not disappeared. Since the eradication of smallpox and the cessation of the related vaccination campaigns, the threat has been growing, as evidenced by the currently ongoing worldwide Mpox outbreak. In addition to threats of an evolving Mpox, we must also be aware of a myriad of other threats that remain. Many countries still lack biosecurity regulations reflecting the recent technological advances, and the threat of bioterrorism remains ever present. Reconstruction of smallpox is a distinct possibility, as are other scenarios whereby other orthopox viruses may be made more fit for transmission in humans. OBJECTIVES: To outline and discuss potential biosafety and biosecurity threats posed by orthopox viruses. SOURCES: Published scientific literature, news articles, and international agreements. CONTENT AND IMPLICATIONS: It would be wise to take steps to mitigate these threats now. Vaccination campaigns should be considered in areas with frequent orthopox outbreaks, and more efforts must be made to put a final end to the Mpox outbreak. In many countries, national biosafety and biosecurity regulations may need to be revised and strengthened to better reflect the threats posed by new technologies, including controls on synthesis of smallpox sequences. Furthermore, more international cooperation and aid is needed. The present global Mpox outbreak could likely have been prevented had areas where Mpox is endemic not been neglected. Future outbreaks could be much worse.


Asunto(s)
Brotes de Enfermedades , Orthopoxvirus , Humanos , Brotes de Enfermedades/prevención & control , Infecciones por Poxviridae/prevención & control , Infecciones por Poxviridae/epidemiología , Viruela/prevención & control , Viruela/epidemiología , Animales , Contención de Riesgos Biológicos/métodos , Bioterrorismo/prevención & control , Vacunación
8.
Virus Res ; 339: 199255, 2024 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-38389324

RESUMEN

SARS-CoV-2's genetic plasticity has led to several variants of concern (VOCs). Here we studied replicative capacity for seven SARS-CoV-2 isolates (B.1, Alpha, Beta, Gamma, Delta, Zeta, and Omicron BA.1) in primary reconstituted airway epithelia (HAE) and lung-derived cell lines. Furthermore, to investigate the host range of Delta and Omicron compared to ancestral SARS-CoV-2, we assessed replication in 17 cell lines from 11 non-primate mammalian species, including bats, rodents, insectivores and carnivores. Only Omicron's phenotype differed in vitro, with rapid but short replication and efficient production of infectious virus in nasal HAEs, in contrast to other VOCs, but not in lung cell lines. No increased infection efficiency for other species was observed, but Delta and Omicron infection efficiency was increased in A549 cells. Notably replication in A549 and Calu3 cells was lower than in nasal HAE. Our results suggest better adaptation of VOCs towards humans, without an extended host range, and may be relevant to the search for the putative intermediate host and reservoirs prior to the pandemic.


Asunto(s)
COVID-19 , Quirópteros , Animales , Humanos , SARS-CoV-2 , Mamíferos , Línea Celular
9.
Open Forum Infect Dis ; 10(12): ofad595, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38094666

RESUMEN

Among 292 recipients of allogeneic hematopoietic cell transplant (2018-2022), 64 (21.9%) tested positive for anti-hepatitis E virus (HEV) immunoglobulin G. Among 208 recipients tested by plasma/serum HEV polymerase chain reaction (2012-2022), 3 (1.4%) primary HEV infections were diagnosed; in 1 patient, plasma HEV polymerase chain reaction relapsed positive for 100 days. HEV infection remains rare albeit associated with persistent viral replication.

10.
EBioMedicine ; 98: 104893, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38035462

RESUMEN

BACKGROUND: Mucosal antibodies play a key role in the protection against SARS-CoV-2 infection in the upper respiratory tract, and potentially in limiting virus replication and therefore onward transmission. While systemic immunity to SARS-CoV-2 is well understood, we have a limited understanding about the antibodies present on the nasal mucosal surfaces. METHODS: In this study, we evaluated SARS-CoV-2 mucosal antibodies following previous infection, vaccination, or a combination of both. Paired nasal fluid and serum samples were collected from 143 individuals, which include convalescent, vaccinated, or breakthrough infections. FINDINGS: We detected a high correlation between IgG responses in serum and nasal fluids, which were higher in both compartments in vaccinated compared to convalescent participants. Contrary, nasal and systemic SARS-CoV-2 IgA responses were weakly correlated, indicating a compartmentalization between the local and systemic IgA responses. SARS-CoV-2 secretory component IgA (s-IgA) antibodies, present exclusively on mucosal surfaces, were detected in the nasal fluid only in a minority of vaccinated subjects and were significantly higher in previously infected individuals. Depletion of IgA antibodies in nasal fluids resulted in a tremendous reduction of neutralization activity against SARS-CoV-2, indicating that IgA is the crucial contributor to neutralization in the nasal mucosa. Neutralization against SARS-CoV-2 was higher in the mucosa of subjects with previous SARS-CoV-2 infections compared to vaccinated participants. INTERPRETATION: In summary, we demonstrate that currently available vaccines elicit strong systemic antibody responses, but SARS-CoV-2 infection generates higher titers of binding and neutralizing mucosal antibodies. Our results support the importance to develop SARS-CoV-2 vaccines that elicit mucosal antibodies. FUNDING: The work was funded by the COVID-19 National Research Program 78 (grant number 198412) of the Swiss National Science Foundation.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Inmunidad Mucosa , Vacunas contra la COVID-19 , Convalecencia , Inmunoglobulina A Secretora , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Inmunidad Adaptativa , Inmunoglobulina A
11.
Viruses ; 15(11)2023 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-38005845

RESUMEN

With nearly half of the world's population being at risk of infection, dengue virus represents a major global health issue. The use of dengue antigen rapid diagnostic tests (Ag-RDTs) represents an alternative to PCR methods for the diagnosis of acute infections since they display excellent sensitivities and specificities and can be performed outside the laboratory. The high genetic diversity of the dengue virus genome represents a challenge for vaccine development, and the progressive expansion of this virus into previously nonendemic regions justifies the implementation of a genomic surveillance program. In this proof-of-concept study, we show the feasibility of sequencing dengue virus genomes directly from positive Ag-RDT (Standard Q Dengue Duo Test assay, n = 7) cassettes stored up to 31 days at room temperature after testing. For 5 of the 7 samples, a high number of reads were obtained allowing phylogenetic analyses to be carried out to determine not only the serotypes (dengue 1, 2, 3 and 4 were detected) but also the genotypes. Furthermore, in one sample, our unbiased metagenomic next-generation sequencing approach made it possible to detect epizootic hemorrhagic disease virus sequences, an arthropod-transmitted virus in ruminants. To conclude, as such an approach requires no cold storage or freezing of samples, dengue Ag-RDTs represent a very pragmatic and robust alternative for the genomic surveillance of dengue virus.


Asunto(s)
Virus del Dengue , Dengue , Humanos , Dengue/epidemiología , Filogenia , Sensibilidad y Especificidad , Proteínas no Estructurales Virales/genética , Inmunoglobulina M , Genoma Viral , Ensayo de Inmunoadsorción Enzimática , Anticuerpos Antivirales
12.
Vaccine X ; 15: 100383, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37841654

RESUMEN

Whilst it is now widely recognised that routine immunisation (RI) was disrupted by the COVID-19 pandemic in 2020, and further so in 2021, the extent of continued interruptions in 2022 and/or rebounds to previous trends remains unclear. We modelled country-specific RI trends using validated estimates of national coverage from the World Health Organisation and United Nation Children's Fund for 182 countries (accounting for > 97% of children globally), to project expected diphtheria, tetanus, and pertussis-containing vaccine first-dose (DTP1), third-dose (DTP3) and measles-containing vaccine first-dose (MCV1) coverage for 2020-2022 based on pre-pandemic trends (from 2000 to 2019). We provide further evidence of peak pandemic immunisation disruption in 2021, followed by tentative recovery in 2022. We report a 3.4% (95 %CI: [2.5%; 4.4%]) decline in global DTP3 coverage in 2021 compared to 2000-2019 trends, from an expected 89.8% to reported 86.4%. This coverage gap reduced to a 2.7% (95 %CI: [1.8%; 3.6%]) decline in 2022, with reported coverage rising to 87.2%. Similar results were seen for DTP1 and MCV1. Whilst partial rebounds are encouraging, global coverage decline translates to a 17-year setback in RI to 2005 levels, and the majority of countries retain coverage at or lower than pre-pandemic levels. The Americas, Africa, and Asia were the most impacted regions; and low- and middle-income countries the most affected income groups. The number of annual Zero Dose (ZD) children - indicating those receiving no immunisations - increased from 12.1 million (M) globally in 2019 to a peak of 16.7 M in 2021, then reduced to 13.1 M in 2022. Overall, we estimate an excess of 8.8 M ZD children cumulatively in 2020-2022 compared to pre-pandemic levels. This work can be used as an objective baseline to inform future interventions to prioritise and target interventions, and facilitate catch-up of growing populations of under- and un-immunised children.

14.
Int J Mol Sci ; 24(20)2023 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-37895062

RESUMEN

Influenza virus is one of the main causes of respiratory infections worldwide. Despite the availability of seasonal vaccines and antivirals, influenza virus infections cause an important health and economic burden. Therefore, the need to identify alternative antiviral strategies persists. In this study, we identified non-steroidal estrogens as potent inhibitors of influenza virus due to their interaction with the hemagglutinin protein, preventing viral entry. This activity is maintained in vitro, ex vivo, and in vivo. Therefore, we found a new domain to target on the hemagglutinin and a class of compounds that could be further optimized for influenza treatment.


Asunto(s)
Estrógenos no Esteroides , Gripe Humana , Infecciones por Orthomyxoviridae , Orthomyxoviridae , Humanos , Hemaglutininas , Infecciones por Orthomyxoviridae/tratamiento farmacológico , Infecciones por Orthomyxoviridae/prevención & control , Orthomyxoviridae/metabolismo , Glicoproteínas Hemaglutininas del Virus de la Influenza/metabolismo , Antivirales/farmacología
15.
Diagn Progn Res ; 7(1): 16, 2023 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-37667327

RESUMEN

BACKGROUND: A previous individual participant data meta-analysis (IPD-MA) of antibiotics for adults with clinically diagnosed acute rhinosinusitis (ARS) showed a marginal overall effect of antibiotics, but was unable to identify patients that are most likely to benefit from antibiotics when applying conventional (i.e. univariable or one-variable-at-a-time) subgroup analysis. We updated the systematic review and investigated whether multivariable prediction of patient-level prognosis and antibiotic treatment effect may lead to more tailored treatment assignment in adults presenting to primary care with ARS. METHODS: An IPD-MA of nine double-blind placebo-controlled trials of antibiotic treatment (n=2539) was conducted, with the probability of being cured at 8-15 days as the primary outcome. A logistic mixed effects model was developed to predict the probability of being cured based on demographic characteristics, signs and symptoms, and antibiotic treatment assignment. Predictive performance was quantified based on internal-external cross-validation in terms of calibration and discrimination performance, overall model fit, and the accuracy of individual predictions. RESULTS: Results indicate that the prognosis with respect to risk of cure could not be reliably predicted (c-statistic 0.58 and Brier score 0.24). Similarly, patient-level treatment effect predictions did not reliably distinguish between those that did and did not benefit from antibiotics (c-for-benefit 0.50). CONCLUSIONS: In conclusion, multivariable prediction based on patient demographics and common signs and symptoms did not reliably predict the patient-level probability of cure and antibiotic effect in this IPD-MA. Therefore, these characteristics cannot be expected to reliably distinguish those that do and do not benefit from antibiotics in adults presenting to primary care with ARS.

16.
Sci Rep ; 13(1): 10759, 2023 07 04.
Artículo en Inglés | MEDLINE | ID: mdl-37402726

RESUMEN

Experts have warned against the pandemic burden on healthcare workers early on, however little is known about the evolution of this burden with time, in addition to the long-term effects of post-COVID symptoms in healthcare workers. Staff at the Geneva University Hospitals in Switzerland had an online follow-up in July and December 2021, on their physical and mental health, quality of life and functional capacity using validated scales. Descriptive analyses compared the prevalence of symptoms, functional impairment and quality of life in SARS-CoV-2 positive and negative individuals at baseline and at follow-up. Out of the initial n = 3,083 participants that answered at baseline in July 2021, n = 900 (mean age of 46.4 years, 70.1% women) completed the follow-up in December 2021. With time, more individuals reported fatigue (+ 9.4%), headache (+ 9.0%), insomnia (+ 2.3%), cognitive impairment (+ 1.4%), stress/burnout (+ 8.8%), pain (+ 8.3%), digestive symptoms (+ 3.6%), dyspnea (+ 1.0%), and cough (+ 7.7%) compared to baseline, with a differentially larger increase in symptoms in the SARS-CoV-2 negative group. Individuals had more functional impairment (12.7% at baseline and 23.9% at follow-up), with more absenteeism and worsening quality of life. Healthcare workers are potentially suffering from long term consequences of the pandemic burden, calling for urgent action and solutions.


Asunto(s)
Absentismo , COVID-19 , Personal de Salud , Pandemias , COVID-19/psicología , Personal de Salud/psicología , Humanos , Calidad de Vida , Estrés Psicológico , Estudios Longitudinales , Prevalencia , Masculino , Femenino , Persona de Mediana Edad , SARS-CoV-2/fisiología , Salud Pública , Admisión y Programación de Personal
17.
Viruses ; 15(7)2023 07 19.
Artículo en Inglés | MEDLINE | ID: mdl-37515261

RESUMEN

Anelloviruses are extremely prevalent in the human population and are considered to be commensal parts of the human virome. The best-known member in humans is the Torque teno virus. Recent metagenomic next-generation sequencing investigations have helped reveal the considerable number of species and genotypes from the same genus that can be co-detected within a single individual and that this diversity increases as a function of age during the first months/years of life. As a result, to date, the bioinformatics analysis of this genetic diversity remains complex and constraining for researchers. Here, we present SCANellome, a user-friendly tool to investigate the anellome composition at the genus, species, and genotype levels of samples from metagenomics data generated by the Illumina and Nanopore platforms. SCANellome is based on an in-house up-to-date database that includes all human and non-human primate anellovirus reference sequences available on GenBank and meets the latest classification criteria established by the International Committee on Taxonomy of Viruses.


Asunto(s)
Anelloviridae , Torque teno virus , Virus , Humanos , Animales , Anelloviridae/genética , Metagenómica , Virus/genética , Primates
18.
Curr Opin Infect Dis ; 36(4): 243-249, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37260265

RESUMEN

PURPOSE OF REVIEW: Allogeneic hematopoietic cell transplantation (allogeneic HCT) is a highly effective therapy for a broad range of hematological diseases and its use is increasing worldwide. Despite advances in antiviral prophylaxis and treatment, viral infections are still one of the leading causes of post-HCT morbidity and mortality. In this patient population, metagenomic next-generation sequencing (mNGS) revealed a much larger diversity of viruses than previously suspected via the targeted screening approach. In the context of profound immunosuppression, these viral infections may cause transient viremia or protracted replication and potentially be associated with yet unrecognized or unspecific clinical manifestations. On the contrary, by constantly interacting with the immune system, viral infections may have a significant impact on posttransplant outcomes. Here, we review the latest advances in research assessing the role of the blood virome in the development of post-HCT complications. RECENT FINDINGS: Research efforts are under way to uncover the potential role of several previously undetected viruses in the development of allogeneic HCT complications and their impact on transplant outcomes. SUMMARY: The identification of viral actors impacting post-HCT morbidity and survival is key to optimize monitoring and infection prevention/treatment strategies.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Humanos , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Receptores de Trasplantes , Viroma , Terapia de Inmunosupresión
19.
Nat Commun ; 14(1): 3032, 2023 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-37230973

RESUMEN

Binding antibody levels against SARS-CoV-2 have shown to be correlates of protection against infection with pre-Omicron lineages. This has been challenged by the emergence of immune-evasive variants, notably the Omicron sublineages, in an evolving immune landscape with high levels of cumulative incidence and vaccination coverage. This in turn limits the use of widely available commercial high-throughput methods to quantify binding antibodies as a tool to monitor protection at the population-level. Here we show that anti-Spike RBD antibody levels, as quantified by the immunoassay used in this study, are an indirect correlate of protection against Omicron BA.1/BA.2 for individuals previously infected by SARS-CoV-2. Leveraging repeated serological measurements between April 2020 and December 2021 on 1083 participants of a population-based cohort in Geneva, Switzerland, and using antibody kinetic modeling, we found up to a three-fold reduction in the hazard of having a documented positive SARS-CoV-2 infection during the Omicron BA.1/BA.2 wave for anti-S antibody levels above 800 IU/mL (HR 0.30, 95% CI 0.22-0.41). However, we did not detect a reduction in hazard among uninfected participants. These results provide reassuring insights into the continued interpretation of SARS-CoV-2 binding antibody measurements as an independent marker of protection at both the individual and population levels.


Asunto(s)
COVID-19 , Humanos , SARS-CoV-2 , Anticuerpos Antivirales , Evasión Inmune , Cinética , Anticuerpos Neutralizantes
20.
Proc Natl Acad Sci U S A ; 120(21): e2214936120, 2023 05 23.
Artículo en Inglés | MEDLINE | ID: mdl-37192162

RESUMEN

Influenza A virus (IAV) enters host cells mostly through clathrin-dependent receptor-mediated endocytosis. A single bona fide entry receptor protein supporting this entry mechanism remains elusive. Here we performed proximity ligation of biotin to host cell surface proteins in the vicinity of attached trimeric hemagglutinin-HRP and characterized biotinylated targets using mass spectrometry. This approach identified transferrin receptor 1 (TfR1) as a candidate entry protein. Genetic gain-of-function and loss-of-function experiments, as well as in vitro and in vivo chemical inhibition, confirmed the functional involvement of TfR1 in IAV entry. Recycling deficient mutants of TfR1 do not support entry, indicating that TfR1 recycling is essential for this function. The binding of virions to TfR1 via sialic acids confirmed its role as a directly acting entry factor, but unexpectedly even headless TfR1 promoted IAV particle uptake in trans. TIRF microscopy localized the entering virus-like particles in the vicinity of TfR1. Our data identify TfR1 recycling as a revolving door mechanism exploited by IAV to enter host cells.


Asunto(s)
Virus de la Influenza A , Transferrina , Virus de la Influenza A/fisiología , Internalización del Virus , Endocitosis/fisiología , Receptores de Transferrina/genética , Receptores de Transferrina/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...