Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 126
Filtrar
1.
PLoS Pathog ; 20(4): e1011680, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38635853

RESUMEN

To mitigate the loss of lives during the COVID-19 pandemic, emergency use authorization was given to several anti-SARS-CoV-2 monoclonal antibody (mAb) therapies for the treatment of mild-to-moderate COVID-19 in patients with a high risk of progressing to severe disease. Monoclonal antibodies used to treat SARS-CoV-2 target the spike protein of the virus and block its ability to enter and infect target cells. Monoclonal antibody therapy can thus accelerate the decline in viral load and lower hospitalization rates among high-risk patients with variants susceptible to mAb therapy. However, viral resistance has been observed, in some cases leading to a transient viral rebound that can be as large as 3-4 orders of magnitude. As mAbs represent a proven treatment choice for SARS-CoV-2 and other viral infections, evaluation of treatment-emergent mAb resistance can help uncover underlying pathobiology of SARS-CoV-2 infection and may also help in the development of the next generation of mAb therapies. Although resistance can be expected, the large rebounds observed are much more difficult to explain. We hypothesize replenishment of target cells is necessary to generate the high transient viral rebound. Thus, we formulated two models with different mechanisms for target cell replenishment (homeostatic proliferation and return from an innate immune response antiviral state) and fit them to data from persons with SARS-CoV-2 treated with a mAb. We showed that both models can explain the emergence of resistant virus associated with high transient viral rebounds. We found that variations in the target cell supply rate and adaptive immunity parameters have a strong impact on the magnitude or observability of the viral rebound associated with the emergence of resistant virus. Both variations in target cell supply rate and adaptive immunity parameters may explain why only some individuals develop observable transient resistant viral rebound. Our study highlights the conditions that can lead to resistance and subsequent viral rebound in mAb treatments during acute infection.


Asunto(s)
Anticuerpos Monoclonales , Tratamiento Farmacológico de COVID-19 , COVID-19 , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Humanos , SARS-CoV-2/inmunología , SARS-CoV-2/efectos de los fármacos , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , COVID-19/inmunología , COVID-19/virología , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/uso terapéutico , Farmacorresistencia Viral/inmunología , Carga Viral/efectos de los fármacos , Antivirales/uso terapéutico , Antivirales/farmacología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/uso terapéutico
2.
Artículo en Inglés | MEDLINE | ID: mdl-37817300

RESUMEN

As part of its role in the World Health Organization's (WHO) Global Influenza Surveillance and Response System (GISRS), the WHO Collaborating Centre for Reference and Research on Influenza in Melbourne received a record total of 12,073 human influenza positive samples during 2022. Viruses were analysed for their antigenic, genetic and antiviral susceptibility properties. Selected viruses were propagated in qualified cells or embryonated hen's eggs for potential use in seasonal influenza virus vaccines. In 2022, influenza A(H3N2) viruses predominated over influenza A(H1N1)pdm09 and B viruses, accounting for 77% of all viruses analysed. The majority of A(H1N1)pdm09, A(H3N2) and influenza B viruses analysed at the Centre were found to be antigenically and genetically similar to the respective WHO recommended vaccine strains for the southern hemisphere in 2022. Of 3,372 samples tested for susceptibility to the neuraminidase inhibitors oseltamivir and zanamivir, two A(H1N1)pdm09 viruses showed highly reduced inhibition against oseltamivir.


Asunto(s)
Virus de la Influenza A , Vacunas contra la Influenza , Gripe Humana , Animales , Femenino , Humanos , Australia/epidemiología , Pollos , Farmacorresistencia Viral/genética , Farmacorresistencia Viral/inmunología , Virus de la Influenza A/efectos de los fármacos , Virus de la Influenza A/genética , Virus de la Influenza A/inmunología , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H3N2 del Virus de la Influenza A/genética , Vacunas contra la Influenza/genética , Vacunas contra la Influenza/inmunología , Vacunas contra la Influenza/uso terapéutico , Gripe Humana/epidemiología , Gripe Humana/genética , Gripe Humana/inmunología , Gripe Humana/prevención & control , Oseltamivir/farmacología , Organización Mundial de la Salud , Zanamivir/farmacología , Antivirales/farmacología
4.
Nat Hum Behav ; 6(2): 193-206, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35210582

RESUMEN

The greatest hope for a return to normalcy following the COVID-19 pandemic is worldwide vaccination. Yet, a relaxation of social distancing that allows increased transmissibility, coupled with selection pressure due to vaccination, will probably lead to the emergence of vaccine resistance. We analyse the evolutionary dynamics of COVID-19 in the presence of dynamic contact reduction and in response to vaccination. We use infection and vaccination data from six different countries. We show that under slow vaccination, resistance is very likely to appear even if social distancing is maintained. Under fast vaccination, the emergence of mutants can be prevented if social distancing is maintained during vaccination. We analyse multiple human factors that affect the evolutionary potential of the virus, including the extent of dynamic social distancing, vaccination campaigns, vaccine design, boosters and vaccine hesitancy. We provide guidelines for policies that aim to minimize the probability of emergence of vaccine-resistant variants.


Asunto(s)
Vacunas contra la COVID-19 , Farmacorresistencia Viral , Inmunogenicidad Vacunal , Vacunación Masiva , Distanciamiento Físico , SARS-CoV-2 , COVID-19 , Vacunas contra la COVID-19/inmunología , Vacunas contra la COVID-19/farmacología , Control de Enfermedades Transmisibles/organización & administración , Farmacorresistencia Viral/efectos de los fármacos , Farmacorresistencia Viral/inmunología , Modelos Epidemiológicos , Humanos , Vacunación Masiva/métodos , Vacunación Masiva/estadística & datos numéricos , Formulación de Políticas , Probabilidad , SARS-CoV-2/efectos de los fármacos , SARS-CoV-2/fisiología , Procesos Estocásticos , Vacilación a la Vacunación , Eficacia de las Vacunas
5.
Elife ; 102021 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-34061023

RESUMEN

Background: Considering the remaining threat of drug-resistantmutations (DRMs) to antiretroviral treatment (ART) efficacy, we investigated how the selective pressure of human leukocyte antigen (HLA)-restricted cytotoxic T lymphocytes drives certain DRMs' emergence and retention. Methods: We systematically screened DRM:HLA class I allele combinations in 3997 ART-naïve Swiss HIV Cohort Study (SHCS) patients. For each pair, a logistic regression model preliminarily tested for an association with the DRM as the outcome. The three HLA:DRM pairs remaining after multiple testing adjustment were analyzed in three ways: cross-sectional logistic regression models to determine any HLA/infection time interaction, survival analyses to examine if HLA type correlated with developing specific DRMs, and via NetMHCpan to find epitope binding evidence of immune escape. Results: Only one pair, RT-E138:HLA-B18, exhibited a significant interaction between infection duration and HLA. The survival analyses predicted two pairs with an increased hazard of developing DRMs: RT-E138:HLA-B18 and RT-V179:HLA-B35. RT-E138:HLA-B18 exhibited the greatest significance in both analyses (interaction term odds ratio [OR] 1.169 [95% confidence interval (CI) 1.075-1.273]; p-value<0.001; survival hazard ratio 12.211 [95% CI 3.523-42.318]; p-value<0.001). The same two pairs were also predicted by netMHCpan to have epitopic binding. Conclusions: We identified DRM:HLA pairs where HLA presence is associated with the presence or emergence of the DRM, indicating that the selective pressure for these mutations alternates direction depending on the presence of these HLA alleles. Funding: Funded by the Swiss National Science Foundation within the framework of the SHCS, and the University of Zurich, University Research Priority Program: Evolution in Action: From Genomes Ecosystems, in Switzerland.


Asunto(s)
Antirretrovirales/uso terapéutico , Farmacorresistencia Viral/genética , Genoma Humano , Genoma Viral , Infecciones por VIH/tratamiento farmacológico , Antígenos HLA/genética , Mutación , Linfocitos T Citotóxicos/inmunología , Estudios Transversales , Farmacorresistencia Viral/inmunología , Femenino , Infecciones por VIH/genética , Infecciones por VIH/inmunología , Infecciones por VIH/mortalidad , Antígenos HLA/inmunología , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Tasa de Mutación , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Suiza , Resultado del Tratamiento
6.
Nat Rev Immunol ; 21(6): 382-393, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33875867

RESUMEN

Several neutralizing monoclonal antibodies (mAbs) to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been developed and are now under evaluation in clinical trials. With the US Food and Drug Administration recently granting emergency use authorizations for neutralizing mAbs in non-hospitalized patients with mild-to-moderate COVID-19, there is an urgent need to discuss the broader potential of these novel therapies and to develop strategies to deploy them effectively in clinical practice, given limited initial availability. Here, we review the precedent for passive immunization and lessons learned from using antibody therapies for viral infections such as respiratory syncytial virus, Ebola virus and SARS-CoV infections. We then focus on the deployment of convalescent plasma and neutralizing mAbs for treatment of SARS-CoV-2. We review specific clinical questions, including the rationale for stratification of patients, potential biomarkers, known risk factors and temporal considerations for optimal clinical use. To answer these questions, there is a need to understand factors such as the kinetics of viral load and its correlation with clinical outcomes, endogenous antibody responses, pharmacokinetic properties of neutralizing mAbs and the potential benefit of combining antibodies to defend against emerging viral variants.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Neutralizantes/uso terapéutico , Anticuerpos Antivirales/uso terapéutico , COVID-19/terapia , SARS-CoV-2 , Anticuerpos Monoclonales Humanizados/uso terapéutico , Acrecentamiento Dependiente de Anticuerpo , COVID-19/inmunología , COVID-19/virología , Desarrollo de Medicamentos , Farmacorresistencia Viral/genética , Farmacorresistencia Viral/inmunología , Humanos , Inmunización Pasiva/efectos adversos , Inmunización Pasiva/métodos , Modelos Inmunológicos , Pandemias , SARS-CoV-2/efectos de los fármacos , SARS-CoV-2/genética , SARS-CoV-2/inmunología , Sueroterapia para COVID-19
7.
Proc Natl Acad Sci U S A ; 118(14)2021 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-33811145

RESUMEN

Human respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory infection in children under 5 y of age. In the absence of a safe and effective vaccine and with limited options for therapeutic interventions, uncontrolled epidemics of RSV occur annually worldwide. Existing RSV reverse genetics systems have been predominantly based on older laboratory-adapted strains such as A2 or Long. These strains are not representative of currently circulating genotypes and have a convoluted passage history, complicating their use in studies on molecular determinants of viral pathogenesis and intervention strategies. In this study, we have generated reverse genetics systems for clinical isolates of RSV-A (ON1, 0594 strain) and RSV-B (BA9, 9671 strain) in which the full-length complementary DNA (cDNA) copy of the viral antigenome is cloned into a bacterial artificial chromosome (BAC). Additional recombinant (r) RSVs were rescued expressing enhanced green fluorescent protein (EGFP), mScarlet, or NanoLuc luciferase from an additional transcription unit inserted between the P and M genes. Mutations in antigenic site II of the F protein conferring escape from palivizumab neutralization (K272E, K272Q, S275L) were investigated using quantitative cell-fusion assays and rRSVs via the use of BAC recombineering protocols. These mutations enabled RSV-A and -B to escape palivizumab neutralization but had differential impacts on cell-to-cell fusion, as the S275L mutation resulted in an almost-complete ablation of syncytium formation. These reverse genetics systems will facilitate future cross-validation efficacy studies of novel RSV therapeutic intervention strategies and investigations into viral and host factors necessary for virus entry and cell-to-cell spread.


Asunto(s)
Farmacorresistencia Viral/genética , Mutación , Virus Sincitiales Respiratorios/genética , Animales , Antivirales/toxicidad , Chlorocebus aethiops , Farmacorresistencia Viral/inmunología , Células Hep G2 , Humanos , Palivizumab/toxicidad , Infecciones por Virus Sincitial Respiratorio/tratamiento farmacológico , Infecciones por Virus Sincitial Respiratorio/virología , Virus Sincitiales Respiratorios/inmunología , Virus Sincitiales Respiratorios/aislamiento & purificación , Virus Sincitiales Respiratorios/patogenicidad , Genética Inversa/métodos , Células Vero
8.
Nature ; 593(7857): 130-135, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33684923

RESUMEN

The COVID-19 pandemic has had widespread effects across the globe, and its causative agent, SARS-CoV-2, continues to spread. Effective interventions need to be developed to end this pandemic. Single and combination therapies with monoclonal antibodies have received emergency use authorization1-3, and more treatments are under development4-7. Furthermore, multiple vaccine constructs have shown promise8, including two that have an approximately 95% protective efficacy against COVID-199,10. However, these interventions were directed against the initial SARS-CoV-2 virus that emerged in 2019. The recent detection of SARS-CoV-2 variants B.1.1.7 in the UK11 and B.1.351 in South Africa12 is of concern because of their purported ease of transmission and extensive mutations in the spike protein. Here we show that B.1.1.7 is refractory to neutralization by most monoclonal antibodies against the N-terminal domain of the spike protein and is relatively resistant to a few monoclonal antibodies against the receptor-binding domain. It is not more resistant to plasma from individuals who have recovered from COVID-19 or sera from individuals who have been vaccinated against SARS-CoV-2. The B.1.351 variant is not only refractory to neutralization by most monoclonal antibodies against the N-terminal domain but also by multiple individual monoclonal antibodies against the receptor-binding motif of the receptor-binding domain, which is mostly due to a mutation causing an E484K substitution. Moreover, compared to wild-type SARS-CoV-2, B.1.351 is markedly more resistant to neutralization by convalescent plasma (9.4-fold) and sera from individuals who have been vaccinated (10.3-12.4-fold). B.1.351 and emergent variants13,14 with similar mutations in the spike protein present new challenges for monoclonal antibody therapies and threaten the protective efficacy of current vaccines.


Asunto(s)
Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Vacunas contra la COVID-19/inmunología , COVID-19/inmunología , COVID-19/terapia , Evasión Inmune/inmunología , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Adulto , Anciano , Animales , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/uso terapéutico , COVID-19/prevención & control , COVID-19/virología , Chlorocebus aethiops , Farmacorresistencia Viral/inmunología , Células HEK293 , Humanos , Evasión Inmune/genética , Inmunización Pasiva , Persona de Mediana Edad , Modelos Moleculares , Mutación , Pruebas de Neutralización , Dominios Proteicos/inmunología , SARS-CoV-2/química , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Vacunas Sintéticas/inmunología , Células Vero , Sueroterapia para COVID-19 , Tratamiento Farmacológico de COVID-19 , Vacunas de ARNm
9.
PLoS Biol ; 18(11): e3001000, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33166303

RESUMEN

Although less common than the evolution of antimicrobial drug resistance, vaccine resistance can and has evolved. How likely is it that COVID-19 vaccines currently in development will be undermined by viral evolution? We argue that this can be determined by repurposing samples that are already being collected as part of clinical trials. Such information would be useful for prioritizing investment among candidate vaccines and maximizing the potential long-term impact of COVID-19 vaccines.


Asunto(s)
Betacoronavirus/inmunología , Ensayos Clínicos como Asunto , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/virología , Farmacorresistencia Viral/inmunología , Neumonía Viral/inmunología , Neumonía Viral/virología , Vacunas Virales/inmunología , COVID-19 , Vacunas contra la COVID-19 , Infecciones por Coronavirus/prevención & control , Humanos , Pandemias , Factores de Riesgo , SARS-CoV-2
10.
Nat Commun ; 11(1): 3418, 2020 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-32647286

RESUMEN

The emergence and spread of antiviral drug-resistant viruses have been a worldwide challenge and a great concern for patient care. We report A4 antibody specifically recognizing and binding to the mutant I223R/H275Y neuraminidase and prove the applicability of A4 antibody for direct detection of antiviral multidrug-resistant viruses in various sensing platforms, including naked-eye detection, surface-enhanced Raman scattering-based immunoassay, and lateral flow system. The development of the A4 antibody enables fast, simple, and reliable point-of-care assays of antiviral multidrug-resistant influenza viruses. In addition to current influenza virus infection testing methods that do not provide information on the antiviral drug-resistance of the virus, diagnostic tests for antiviral multidrug-resistant viruses will improve clinical judgment in the treatment of influenza virus infections, avoid the unnecessary prescription of ineffective drugs, and improve current therapies.


Asunto(s)
Anticuerpos Antivirales/inmunología , Resistencia a Múltiples Medicamentos/inmunología , Farmacorresistencia Viral/inmunología , Subtipo H1N1 del Virus de la Influenza A/inmunología , Subtipo H3N2 del Virus de la Influenza A/inmunología , Mutación/genética , Neuraminidasa/genética , Secuencia de Aminoácidos , Animales , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/inmunología , Anticuerpos Antivirales/química , Afinidad de Anticuerpos/inmunología , Antígenos Virales/metabolismo , Líquidos Corporales/virología , Análisis Mutacional de ADN , Perros , Epítopos/química , Epítopos/inmunología , Humanos , Subtipo H1N1 del Virus de la Influenza A/enzimología , Subtipo H3N2 del Virus de la Influenza A/enzimología , Células de Riñón Canino Madin Darby , Simulación del Acoplamiento Molecular , Imagen Óptica , Unión Proteica , Espectrometría Raman
11.
Sci Rep ; 10(1): 2227, 2020 02 10.
Artículo en Inglés | MEDLINE | ID: mdl-32042107

RESUMEN

HIV-1 viral transcription persists in patients despite antiretroviral treatment, potentially due to intermittent HIV-1 LTR activation. While several mathematical models have been explored in the context of LTR-protein interactions, in this work for the first time HIV-1 LTR model featuring repressed, intermediate, and activated LTR states is integrated with generation of long (env) and short (TAR) RNAs and proteins (Tat, Pr55, and p24) in T-cells and macrophages using both cell lines and infected primary cells. This type of extended modeling framework allows us to compare and contrast behavior of these two cell types. We demonstrate that they exhibit unique LTR dynamics, which ultimately results in differences in the magnitude of viral products generated. One of the distinctive features of this work is that it relies on experimental data in reaction rate computations. Two RNA transcription rates from the activated promoter states are fit by comparison of experimental data to model predictions. Fitting to the data also provides estimates for the degradation/exit rates for long and short viral RNA. Our experimentally generated data is in reasonable agreement for the T-cell as well macrophage population and gives strong evidence in support of using the proposed integrated modeling paradigm. Sensitivity analysis performed using Latin hypercube sampling method confirms robustness of the model with respect to small parameter perturbations. Finally, incorporation of a transcription inhibitor (F07#13) into the governing equations demonstrates how the model can be used to assess drug efficacy. Collectively, our model indicates transcriptional differences between latently HIV-1 infected T-cells and macrophages and provides a novel platform to study various transcriptional dynamics leading to latency or activation in numerous cell types and physiological conditions.


Asunto(s)
Fármacos Anti-VIH/farmacología , Regulación Viral de la Expresión Génica/inmunología , Infecciones por VIH/tratamiento farmacológico , VIH-1/genética , Macrófagos/inmunología , Linfocitos T/inmunología , Fármacos Anti-VIH/uso terapéutico , Línea Celular , Farmacorresistencia Viral/efectos de los fármacos , Farmacorresistencia Viral/genética , Farmacorresistencia Viral/inmunología , Infecciones por VIH/sangre , Infecciones por VIH/inmunología , Duplicado del Terminal Largo de VIH/genética , VIH-1/efectos de los fármacos , VIH-1/inmunología , Humanos , Macrófagos/virología , Modelos Genéticos , Modelos Inmunológicos , Cultivo Primario de Células , ARN Viral/genética , ARN Viral/metabolismo , Linfocitos T/virología , Transcripción Genética/efectos de los fármacos , Transcripción Genética/inmunología , Replicación Viral/efectos de los fármacos , Replicación Viral/genética , Replicación Viral/inmunología
12.
Sci Rep ; 9(1): 14696, 2019 10 11.
Artículo en Inglés | MEDLINE | ID: mdl-31604961

RESUMEN

Broadly neutralizing antibodies (bNAbs) targeting the HIV-1 envelope glycoprotein (Env) have promising utility in prevention and treatment of HIV-1 infection, and several are currently undergoing clinical trials. Due to the high sequence diversity and mutation rate of HIV-1, viral isolates are often resistant to specific bNAbs. Currently, resistant isolates are commonly identified by time-consuming and expensive in vitro neutralization assays. Here, we report machine learning classifiers that accurately predict resistance of HIV-1 isolates to 33 bNAbs. Notably, our classifiers achieved an overall prediction accuracy of 96% for 212 clinical isolates from patients enrolled in four different clinical trials. Moreover, use of gradient boosting machine - a tree-based machine learning method - enabled us to identify critical features, which had high accordance with epitope residues that distinguished between antibody resistance and sensitivity. The availability of an in silico antibody resistance predictor should facilitate informed decisions of antibody usage and sequence-based monitoring of viral escape in clinical settings.


Asunto(s)
Anticuerpos ampliamente neutralizantes/inmunología , Exactitud de los Datos , Aprendizaje Profundo , Farmacorresistencia Viral/inmunología , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Sitios de Unión de Anticuerpos , Simulación por Computador , Mapeo Epitopo/métodos , Infecciones por VIH/virología , VIH-1/clasificación , Humanos , Idiotipos de Inmunoglobulinas/inmunología , Pruebas de Neutralización , Pronóstico , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología
13.
J Clin Invest ; 129(11): 5020-5032, 2019 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-31415240

RESUMEN

BACKGROUNDImpaired T cell immunity in transplant recipients is associated with infection-related morbidity and mortality. We recently reported the successful use of adoptive T cell therapy (ACT) against drug-resistant/recurrent cytomegalovirus in solid-organ transplant recipients.METHODSIn the present study, we used high-throughput T cell receptor Vß sequencing and T cell functional profiling to delineate the impact of ACT on T cell repertoire remodeling in the context of pretherapy immunity and ACT products.RESULTSThese analyses indicated that a clinical response was coincident with significant changes in the T cell receptor Vß landscape after therapy. This restructuring was associated with the emergence of effector memory T cells in responding patients, while nonresponders displayed dramatic pretherapy T cell expansions with minimal change following ACT. Furthermore, immune reconstitution included both adoptively transferred clonotypes and endogenous clonotypes not detected in the ACT products.CONCLUSIONThese observations demonstrate that immune control following ACT requires significant repertoire remodeling, which may be impaired in nonresponders because of the preexisting immune environment. Immunological interventions that can modulate this environment may improve clinical outcomes.TRIAL REGISTRATIONAustralian New Zealand Clinical Trial Registry, ACTRN12613000981729.FUNDINGThis study was supported by funding from the National Health and Medical Research Council, Australia (APP1132519 and APP1062074).


Asunto(s)
Traslado Adoptivo , Infecciones por Citomegalovirus , Citomegalovirus/inmunología , Farmacorresistencia Viral/inmunología , Trasplante de Órganos , Receptores de Antígenos de Linfocitos T alfa-beta/inmunología , Linfocitos T , Adulto , Infecciones por Citomegalovirus/inmunología , Infecciones por Citomegalovirus/patología , Infecciones por Citomegalovirus/terapia , Femenino , Humanos , Masculino , Linfocitos T/inmunología , Linfocitos T/patología , Linfocitos T/trasplante
14.
Prensa méd. argent ; 105(3): 99-105, may 2019. tab
Artículo en Español | BINACIS, LILACS | ID: biblio-1025198

RESUMEN

Introducción: El tratamiento antirretroviral de alta eficacia (TARGA) ha desplazado a las infecciones oportunistas como principal causa de hospitalización en infectados por el HIV. Sin embargo, algunos autores hallaron que las causas de internación por HIV en Buenos Aires no cambiaron a pesar del acceso universal al TARGA desde 1996. Pacientes y Métodos. Para confirmar estos resultados revisamos todos los ingresos hospitalarios ocurridos durante tres años en un hospital general de la ciudad de Buenos Aires. Resultados: 57 pacientes (34 hombres) tuvieron 79 hospitalizaciones: 43 ingresaron sólo una vez y los 14 restantes tuvieron dos o más ingresos hasta totalizar 36 internaciones. La edad fue de 44.46 ± 11.55 años (promedio ± desvío estándard), 43 pacientes (75.45%) se sabían HIV + y 28 de ellos (65.12%) recibían TARGA al ingreso, 31 hospitalizaciones (39.24%) fueron causadas por enfermedades marcadoras de SIDA; 35 (44.30%) por infecciones no marcadoras de SIDA (INMS) y 13 (13.46%) por enfermedades no infecciosas. Tuberculosis fue el diagnóstico más frecuente (11 casos, 13.92%), seguida por meningitis a Cryptococcus neoformans en 9 (11.39%) y toxoplasmosis cerebral en 6 (7.59%). Entre las INMS, la neumonía fue la principal causa de hospitalización (13 pacientes, 16.46%). Discusión: Estos resultados confirman resultados previos comunicando que las causas de hospitalización en infectados por el HIV no cambiaron en respuesta al TARGA en Buenos Aires, lo que puede estar reflejando problemas de detección o adherencia, o puede estar relacionado con resistencia viral, razones sociales o cualquier combinación de estos factores (AU)


Introduction. High Active Antiretroviral Treatment (HAART) displaced opportunistic infections as the main cause of hospitalization in HIV infected patients. However, some authors found that causes for hospitalization in HiV infected patients did not changed at Buenos Aires although this country offers universal access to HAART since 1996. Patients and Methods. We analyzed all the HIV related admissions recorded during three years at a general hospital. Results. 57 patients (34 men) were hospitalized 79 times. 43 out of them were hospitalized only one time. The reaining 14 were hospitalized 36 times. Age was 44.46 ± 11.55 years (mean ± standard deviation). 43 patients (75.45%) had a previous diagnosis of HIV infection. 28 of them (65.12%) received HAART. 31 hospitalizations (39.24%) were caused by AIDS defining events. 35 (44.30%) related to non-AIDS-defining infections diseases (NADID), and 13 (13.46%) to non-infections diseases. Tuberculosis was the prevalent illness (11 cases, 13.92%), followed by cryptoccal meningitis in 9 (11.39%) and cerebral toxoplasmosis in 6 (7.59%). Among NADID, pneumonia was the main cause of admission (13 patientes, 16,46%). Discussion: These results confirm previous reports showing that causes of HIV related hospitalization remain unchanged in spite of HAART at Buenos Aires, which may be reflecting problems of detection and adherence, or may be related to local viral resistance, social reasons, or any combination of these factors (AU)


Asunto(s)
Humanos , Adulto , Persona de Mediana Edad , Enfermedades Transmisibles/diagnóstico , Estudios Retrospectivos , VIH/inmunología , Terapia Antirretroviral Altamente Activa/estadística & datos numéricos , Farmacorresistencia Viral/inmunología , Enfermedades no Transmisibles , Pacientes Internos/estadística & datos numéricos
15.
PLoS One ; 14(1): e0209605, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30650082

RESUMEN

The prevalence of transmitted drug resistance (TDR) in antiretroviral therapy (ART)-naïve individuals remains stable in most developed countries despite a decrease in the prevalence of acquired drug resistance. This suggests that persistence and further transmission of HIV-1 that encodes transmitted drug resistance mutations (TDRMs) is occurring in ART-naïve individuals. In this study, we analysed the prevalence and persistence of TDRMs in the protease and reverse transcriptase-sequences of ART-naïve patients within the German HIV-1 Seroconverter Study Cohort who were infected between 1996 and 2017. The prevalence of TDRMs and baseline susceptibility to antiretroviral drugs were assessed using the Stanford HIVdb list and algorithm. Mean survival times of TDRMs were calculated by Kaplan-Meier analysis. The overall prevalence of TDR was 17.2% (95% CI 15.7-18.6, N = 466/2715). Transmitted NNRTI resistance was observed most frequently with 7.8% (95% CI 6.8-8.8), followed by NRTI resistance (5.0%, 95% CI 4.2-5.9) and PI resistance (2.8%, 95% CI 2.2-3.4). Total TDR (OR = 0.89, p = 0.034) and transmitted NRTI resistance (OR = 0.65, p = 0.000) decreased between 1996 and 2017 but has remained stable during the last decade. Viral susceptibility to NNRTIs (6.5%-6.9% for individual drugs) was mainly reduced, while <3% of the recommended NRTIs and PIs were affected. The longest mean survival times were calculated for the NNRTI mutations K103N (5.3 years, 95% CI 4.2-5.6) and E138A/G/K (8.0 years, 95% CI 5.8-10.2 / 7.9 years, 95% CI 5.4-10.3 / 6.7 years, 95% CI 6.7-6.7) and for the NRTI mutation M41L (6.4 years, 95% CI 6.0-6.7).The long persistence of single TDRMs indicates that onward transmission from ART-naïve individuals is the main cause for TDR in Germany. Transmitted NNRTI resistance was the most frequent TDR, showing simultaneously the highest impact on baseline ART susceptibility and on TDRMs with prolonged persistence. These results give cause for concern regarding the use of NNRTI in first-line regimens.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Seropositividad para VIH/tratamiento farmacológico , VIH-1/genética , VIH-1/inmunología , Adulto , Antirretrovirales/uso terapéutico , Estudios de Cohortes , Farmacorresistencia Viral/genética , Farmacorresistencia Viral/inmunología , Femenino , Alemania , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Seropositividad para VIH/virología , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Mutación , Nucleósidos/uso terapéutico , Prevalencia , Inhibidores de la Transcriptasa Inversa/uso terapéutico , Seroconversión
16.
J Acquir Immune Defic Syndr ; 80(1): 73-78, 2019 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-30334876

RESUMEN

BACKGROUND: The World Health Organization recommends that antiretroviral therapy (ART) programs in resource-limited settings develop third-line ART policies. South Africa developed a national third-line ART program for patients who have failed both first-line non-nucleoside reverse transcriptase inhibitor-based ART and second-line protease inhibitor (PI)-based ART. We report on this program. METHODS: Third-line ART in South Africa is accessed through a national committee that assesses eligibility and makes individual regimen recommendations. Criteria for third-line include the following: ≥1 year on PI-based ART with virologic failure, despite adherence optimization, and genotypic antiretroviral resistance test showing PI resistance. We describe baseline characteristics and resistance patterns of this cohort and present longitudinal data on virological suppression rates. RESULTS: Between August 2013 and July 2014, 144 patients were approved for third-line ART. Median age was 41 years [interquartile range (IQR): 19-47]; 60% were women (N = 85). Median CD4 count and viral load were 172 (IQR: 128-351) and 14,759 (IQR: 314-90,378), respectively. About 2.8% started PI-based ART before 2004; 11.1% from 2004 to 2007; 31.3% from 2008 to 2011; and 6.3% from 2012 to 2014 (48.6% unknown start date). Of the 144 patients, 97% and 98% had resistance to lopinavir and atazanavir, respectively; 57% had resistance to darunavir. All were initiated on a regimen containing darunavir, with raltegravir in 101, and etravirine in 33. Among those with at least 1 viral load at least 6 months after third-line approval (n = 118), a large proportion (83%, n = 98) suppressed to <1000 copies per milliliter, and 79% (n = 93) to <400 copies per milliliter. CONCLUSION: A high proportion of third-line patients with follow-up viral loads are virologically suppressed.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Farmacorresistencia Viral/efectos de los fármacos , Infecciones por VIH/tratamiento farmacológico , Carga Viral/efectos de los fármacos , Adulto , Recuento de Linfocito CD4 , Estudios de Cohortes , Farmacorresistencia Viral/inmunología , Quimioterapia Combinada , Femenino , Infecciones por VIH/epidemiología , Infecciones por VIH/inmunología , Humanos , Masculino , Cumplimiento de la Medicación , Persona de Mediana Edad , Sector Público , Sudáfrica/epidemiología , Adulto Joven
17.
Sci Rep ; 8(1): 8078, 2018 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-29799015

RESUMEN

DNA vaccines require a considerable enhancement of immunogenicity. Here, we optimized a prototype DNA vaccine against drug-resistant HIV-1 based on a weak Th2-immunogen, HIV-1 reverse transcriptase (RT). We designed expression-optimized genes encoding inactivated wild-type and drug-resistant RTs (RT-DNAs) and introduced them into mice by intradermal injections followed by electroporation. RT-DNAs were administered as single or double primes with or without cyclic-di-GMP, or as a prime followed by boost with RT-DNA mixed with a luciferase-encoding plasmid ("surrogate challenge"). Repeated primes improved cellular responses and broadened epitope specificity. Addition of cyclic-di-GMP induced a transient increase in IFN-γ production. The strongest anti-RT immune response was achieved in a prime-boost protocol with electroporation by short 100V pulses done using penetrating electrodes. The RT-specific response, dominated by CD4+ T-cells, targeted epitopes at aa 199-220 and aa 528-543. Drug-resistance mutations disrupted the epitope at aa 205-220, while the CTL epitope at aa 202-210 was not affected. Overall, multiparametric optimization of RT strengthened its Th2- performance. A rapid loss of RT/luciferase-expressing cells in the surrogate challenge experiment revealed a lytic potential of anti-RT response. Such lytic CD4+ response would be beneficial for an HIV vaccine due to its comparative insensitivity to immune escape.


Asunto(s)
Vacunas contra el SIDA , Farmacorresistencia Viral , Infecciones por VIH/terapia , Transcriptasa Inversa del VIH/inmunología , Células Th2/inmunología , Vacunación/métodos , Vacunas de ADN , Vacunas contra el SIDA/administración & dosificación , Vacunas contra el SIDA/genética , Animales , Calibración , Células Cultivadas , Codón , Sistemas de Liberación de Medicamentos , Farmacorresistencia Viral/genética , Farmacorresistencia Viral/inmunología , Epítopos/genética , Epítopos/inmunología , Infecciones por VIH/inmunología , Transcriptasa Inversa del VIH/genética , VIH-1/genética , VIH-1/inmunología , Células HeLa , Humanos , Evasión Inmune/genética , Evasión Inmune/inmunología , Inmunización Secundaria/métodos , Inmunización Secundaria/normas , Inmunogenicidad Vacunal/genética , Ratones , Ratones Endogámicos BALB C , Mejoramiento de la Calidad , Células Th2/metabolismo , Vacunación/normas , Vacunas de ADN/administración & dosificación , Vacunas de ADN/genética
18.
J Theor Biol ; 442: 129-138, 2018 04 07.
Artículo en Inglés | MEDLINE | ID: mdl-29355540

RESUMEN

Severe, long-lasting influenza infections are often caused by new strains of the virus. The long duration of these infections leads to an increased opportunity for the emergence of drug resistant mutants. This is particularly problematic since for new strains there is often no vaccine, so drug treatment is the first line of defense. One strategy for trying to minimize drug resistance is to apply drugs periodically. During treatment phases the wild-type virus decreases, but resistant virus might increase; when there is no treatment, wild-type virus will hopefully out-compete the resistant virus, driving down the number of resistant virus. A stochastic model of severe influenza is combined with a model of drug resistance to simulate long-lasting infections and intermittent treatment with two types of antivirals: neuraminidase inhibitors, which block release of virions; and adamantanes, which block replication of virions. Each drug's ability to reduce emergence of drug resistant mutants is investigated. We find that cell regeneration is required for successful implementation of intermittent treatment and that the optimal cycling parameters change with regeneration rate.


Asunto(s)
Antivirales/uso terapéutico , Farmacorresistencia Viral/efectos de los fármacos , Virus de la Influenza A/efectos de los fármacos , Gripe Humana/tratamiento farmacológico , Algoritmos , Farmacorresistencia Viral/genética , Farmacorresistencia Viral/inmunología , Humanos , Virus de la Influenza A/genética , Virus de la Influenza A/inmunología , Vacunas contra la Influenza/inmunología , Vacunas contra la Influenza/uso terapéutico , Gripe Humana/inmunología , Gripe Humana/virología , Modelos Teóricos , Mutación , Factores de Tiempo
19.
Biochem Pharmacol ; 153: 2-11, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29225131

RESUMEN

Tenofovir (TFV) is the cornerstone of the treatment and prophylaxis of HIV infections. It has been routinely used in its prodrug form TDF (tenofovir disoproxil fumarate) combined with emtricitabine ((-)FTC) and other antiretroviral agents. TDF has now been replaced by TAF (tenofovir alafenamide) which allows better uptake by the lymphoid tissue. In combination with elvitegravir (E), cobicistat (C), emtricitabine (F), TAF can be advocated as an STR (single tablet regimen, Genvoya®) for the treatment of HIV infections. In this combination, E and C may in the future be replaced by bictegravir. The prophylaxis of HIV infection is momentarily based upon Truvada®, the combination of F with TDF, which in the future may also be replaced by TAF. TAF (Vemlidy®) has also replaced TDF (Viread®) for the treatment of hepatitis B virus (HBV) infections. Both TDF and TAF offer little or no risk for virus-drug resistance. As compared to TDF, TAF limits the risk for nephrotoxicity and loss of bone mineral density. What remains to be settled, however, before the universal use of TAF could be recommended, is its safety during pregnancy and its applicability in the treatment of tuberculosis, in combination with rifampicin.


Asunto(s)
Adenina/análogos & derivados , Antivirales/administración & dosificación , Infecciones por VIH/tratamiento farmacológico , Hepatitis B/tratamiento farmacológico , Profilaxis Pre-Exposición/métodos , Adenina/administración & dosificación , Alanina , Farmacorresistencia Viral/efectos de los fármacos , Farmacorresistencia Viral/inmunología , Quimioterapia Combinada/métodos , Infecciones por VIH/inmunología , Hepatitis B/inmunología , Humanos , Tenofovir/análogos & derivados , Resultado del Tratamiento
20.
PLoS Comput Biol ; 13(10): e1005789, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29065122

RESUMEN

Treatment with broadly neutralizing antibodies (bNAbs) has proven effective against HIV-1 infections in humanized mice, non-human primates, and humans. Due to the high mutation rate of HIV-1, resistance testing of the patient's viral strains to the bNAbs is still inevitable. So far, bNAb resistance can only be tested in expensive and time-consuming neutralization experiments. Here, we introduce well-performing computational models that predict the neutralization response of HIV-1 to bNAbs given only the envelope sequence of the virus. Using non-linear support vector machines based on a string kernel, the models learnt even the important binding sites of bNAbs with more complex epitopes, i.e., the CD4 binding site targeting bNAbs, proving thereby the biological relevance of the models. To increase the interpretability of the models, we additionally provide a new kind of motif logo for each query sequence, visualizing those residues of the test sequence that influenced the prediction outcome the most. Moreover, we predicted the neutralization sensitivity of around 34,000 HIV-1 samples from different time points to a broad range of bNAbs, enabling the first analysis of HIV resistance to bNAbs on a global scale. The analysis showed for many of the bNAbs a trend towards antibody resistance over time, which had previously only been discovered for a small non-representative subset of the global HIV-1 population.


Asunto(s)
Anticuerpos Neutralizantes/química , Anticuerpos Neutralizantes/inmunología , Farmacorresistencia Viral/inmunología , Mapeo Epitopo/métodos , Anticuerpos Anti-VIH/química , Anticuerpos Anti-VIH/inmunología , VIH-1/inmunología , Sitios de Unión , Antígenos CD4 , VIH-1/química , Humanos , Unión Proteica , Mapeo de Interacción de Proteínas/métodos , Análisis de Secuencia de Proteína/métodos , Factores de Tiempo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...