Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
1.
AIDS Res Ther ; 7: 42, 2010 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-21134247

RESUMEN

BACKGROUND: Although antiretroviral therapy (ART) has proven its success against HIV-1, the long lifespan of infected cells and viral latency prevent eradication. In this study we analyzed the sensitivity to ART of HIV-1 strains in naïve, central memory and effector memory CD4+ lymphocyte subsets. METHODS: From five patients cellular HIV-1 infection levels were quantified before and after initiation of therapy (2-5 weeks). Through sequencing the C2V3 region of the HIV-1 gp120 envelope, we studied the effect of short-term therapy on virus variants derived from naïve, central memory and effector memory CD4+ lymphocyte subsets. RESULTS: During short-term ART, HIV-1 infection levels declined in all lymphocyte subsets but not as much as RNA levels in serum. Virus diversity in the naïve and central memory lymphocyte populations remained unchanged, whilst diversity decreased in serum and the effector memory lymphocytes. ART differentially affected the virus populations co-circulating in one individual harboring a dual HIV-1 infection. Changes in V3 charge were found in all individuals after ART initiation with increases within the effector memory subset and decreases found in the naïve cell population. CONCLUSIONS: During early ART virus diversity is affected mainly in the serum and effector memory cell compartments. Differential alterations in V3 charge were observed between effector memory and naïve populations. While certain cell populations can be targeted preferentially during early ART, some virus strains demonstrate varied sensitivity to therapy, as shown from studying two strains within a dual HIV-1 infected individual.

2.
Vaccine ; 33(41): 5481-5487, 2015 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-25667962

RESUMEN

TRANSVAC was a collaborative infrastructure project aimed at enhancing European translational vaccine research and training. The objective of this four year project (2009-2013), funded under the European Commission's (EC) seventh framework programme (FP7), was to support European collaboration in the vaccine field, principally through the provision of transnational access (TNA) to critical vaccine research and development (R&D) infrastructures, as well as by improving and harmonising the services provided by these infrastructures through joint research activities (JRA). The project successfully provided all available services to advance 29 projects and, through engaging all vaccine stakeholders, successfully laid down the blueprint for the implementation of a permanent research infrastructure for early vaccine R&D in Europe.


Asunto(s)
Agencias Internacionales , Cooperación Internacional , Investigación , Vacunas , Biotecnología , Europa (Continente) , Humanos
3.
Expert Rev Vaccines ; 10(12): 1697-708, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22085173

RESUMEN

For over 10 years, the European Vaccine Initiative (EVI; European Malaria Vaccine Initiative until 2009) has contributed to the development of 24 malaria candidate vaccine antigens with 13 vaccine candidates being advanced into Phase I clinical trials, two of which have been transitioned for further clinical development in sub-Saharan Africa. Since its inception the EVI organization has operated as a funding agency, but with a clear service-oriented strategy. The scientific successes and difficulties encountered during these years and how these efforts have led to standardization and harmonization in vaccine development through large-scale European consortia are discussed. In the future, the EVI will remain instrumental in the pharmaceutical and clinical development of vaccines against 'diseases of poverty' with a continued focus on malaria. EVI will continue to focus on funding and managing preclinical evaluation up to Phase I/II clinical trials and strengthening the vaccine-development infrastructure in Europe, albeit with a global orientation.


Asunto(s)
Vacunas contra la Malaria/economía , Malaria/prevención & control , Investigación Biomédica Traslacional/economía , Adyuvantes Inmunológicos/normas , Antígenos Virales/inmunología , Ensayos Clínicos como Asunto , Europa (Continente) , Humanos , Programas de Inmunización/economía , Programas de Inmunización/organización & administración , Cooperación Internacional , Malaria/inmunología , Malaria/virología , Vacunas contra la Malaria/inmunología , Vacunas contra la Malaria/normas , Investigación Biomédica Traslacional/organización & administración , Vacunas de Subunidad/inmunología
4.
Virology ; 393(1): 24-32, 2009 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-19698967

RESUMEN

Viral compartmentalization between naïve and memory CD4(+) T cell subsets has been described, but only for individuals who were receiving antiretroviral therapy (ART). We present here an extensive analysis of the viral quasispecies residing in the naïve, central and effector memory CD4(+) T cell subsets in a number of therapy naïve individuals and representing an array of HIV-1 subtypes. We longitudinally analyzed subset-specific infection and evolution in a subtype B infected individual who switches from CCR5 to dual CCR5/CXCR4 coreceptor usage. We show that the central memory subset, the predominantly infected subset, harbors a more diverse viral population compared to the others. Through sequence analysis of the env C2V3 region we demonstrate a lack of viral compartmentalization among all subsets. Upon coreceptor switch we observe a pronounced increase in the infection level of the naïve population. Our findings emphasize the importance of all CD4(+) T cell subsets to viral evolution.


Asunto(s)
Linfocitos T CD4-Positivos/virología , Infecciones por VIH/inmunología , VIH-1/clasificación , VIH-1/aislamiento & purificación , Subgrupos de Linfocitos T/virología , Adulto , Linfocitos T CD4-Positivos/inmunología , Análisis por Conglomerados , ADN Viral/química , ADN Viral/genética , Femenino , Genotipo , VIH-1/genética , VIH-1/inmunología , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Filogenia , Análisis de Secuencia de ADN , Subgrupos de Linfocitos T/inmunología , Adulto Joven
5.
Virology ; 345(1): 209-19, 2006 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-16246391

RESUMEN

We investigated whether development of mutations leads to loss of CD8 T-cell recognition in HIV-1 infection and is possibly linked to alterations in HIV-1-specific CD4(+) T-cell responses in 2 HIV-infected individuals. In patient, H434 full genome sequencing of HIV-1 biological clones at early and late time points during disease progression showed development of fixed mutations in 16 predicted HIV-specific CTL epitopes. Loss of T-cell recognition and reactivity against wild-type and mutant epitopes was observed primarily for the HLA-B27-restricted KK10 epitope and HLA-A2-restricted SL9 epitope. Similarly, in patient H671, decreasing numbers of HLA-A3-restricted CD8(+) T cells specific for the wild-type RK9 epitope was observed after CTL escape. Only in patient H434 loss of CTL responses was paralleled by a decrease in HIV-specific IL-2(+) CD4(+) T-helper responses. This suggests that loss of T-cell reactivity may not be directly linked to HIV-specific CD4(+) T-cell responses but that increased viremia after CTL escape may influence CD4(+) T-helper responses.


Asunto(s)
Infecciones por VIH/inmunología , VIH-1/inmunología , Linfocitos T Citotóxicos/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Epítopos de Linfocito T/genética , Genoma Viral , Infecciones por VIH/virología , VIH-1/genética , VIH-1/fisiología , Humanos , Recuento de Linfocitos , Mutación , Viremia
6.
J Virol ; 79(17): 11247-58, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16103177

RESUMEN

We aimed to identify cross-clade human immunodeficiency virus type 1 (HIV-1) specific T-cell responses among 10 HLA-typed individuals who were infected with non-B HIV-1 strains (A, AG, C, D, G, or F) and to correlate these responses with genetic variation in documented T-cell epitopes. T-cell reactivity was tested against peptide pools spanning clade B Gag, Pol, Nef, Rev, and Tat consensus, with Gag and Nef providing the highest responses. Nine individuals who responded to clade B Gag demonstrated cross-reactive T-cell responses against clade A and C Gag pools, while six of seven responders to Nef-B reacted to clade A and C Nef pools. An inverse correlation between the height of the T-cell responses and the sequence divergence of the HLA class I-restricted epitopes was identified when we compared autologous Gag and Nef sequences with the reactive consensus pools. This could be explained for the Gag sequences through observed variations in the HLA anchor residues. Through mapping of 30 amino acid cross-clade-reactive regions using Gag-B pools, we were able to link 58% (14/24) of the T-cell responses to regions containing previously described HLA class I-restricted epitopes. Forty-two percent (10/24) of the responses were directed to regions containing new epitopes, for which predicted HLA class I motifs could be recognized in 70% (7/10) of individuals. We demonstrate here that cross-clade T-cell responses are frequently induced in individuals infected with distinct HIV-1 clades, suggesting that interclade variation outside of HLA anchor residues may have less impact on vaccine-induced T-cell reactivity than previously thought.


Asunto(s)
Epítopos de Linfocito T/inmunología , Productos del Gen gag/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Antígenos de Histocompatibilidad Clase I/inmunología , Adulto , Secuencia de Aminoácidos , Reacciones Cruzadas , Epítopos de Linfocito T/genética , Productos del Gen gag/genética , VIH-1/genética , Humanos , Persona de Mediana Edad , Datos de Secuencia Molecular
7.
J Virol ; 77(23): 12430-40, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14610167

RESUMEN

Control of viremia in natural human immunodeficiency virus type 1 (HIV-1) infection in humans is associated with a virus-specific T-cell response. However, still much is unknown with regard to the extent of CD8(+) cytotoxic T-lymphocyte (CTL) responses required to successfully control HIV-1 infection and to what extent CTL epitope escape can account for rises in viral load and ultimate progression to disease. In this study, we chose to monitor through full-length genome sequence of replication-competent biological clones the modifications that occurred within predicted CTL epitopes and to identify whether the alterations resulted in epitope escape from CTL recognition. From an extensive analysis of 59 biological HIV-1 clones generated over a period of 4 years from a single individual in whom the viral load was observed to rise, we identified the locations in the genome of five CD8(+) CTL epitopes. Fixed mutations were identified within the p17, gp120, gp41, Nef, and reverse transcriptase genes. Using a gamma interferon ELIspot assay, we identified for four of the five epitopes with fixed mutations a complete loss of T-cell reactivity against the wild-type epitope and a partial loss of reactivity against the mutant epitope. These results demonstrate the sequential accumulation of CTL escape in a patient during disease progression, indicating that multiple combinations of T-cell epitopes are required to control viremia.


Asunto(s)
Infecciones por VIH/virología , VIH-1/genética , Mutación , Linfocitos T Citotóxicos/inmunología , Secuencia de Aminoácidos , Secuencia de Bases , Cartilla de ADN , Progresión de la Enfermedad , Ensayo de Inmunoadsorción Enzimática , Epítopos/química , Genes Virales , Infecciones por VIH/inmunología , VIH-1/fisiología , Humanos , Datos de Secuencia Molecular , Homología de Secuencia de Aminoácido , Replicación Viral/inmunología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA