RESUMO
Despite antiretroviral therapy, proviral latency of human immunodeficiency virus type 1 (HIV-1) remains a principal obstacle to curing the infection. Inducing the expression of latent genomes within resting CD4(+) T cells is the primary strategy to clear this reservoir. Although histone deacetylase inhibitors such as suberoylanilide hydroxamic acid (also known as vorinostat, VOR) can disrupt HIV-1 latency in vitro, the utility of this approach has never been directly proven in a translational clinical study of HIV-infected patients. Here we isolated the circulating resting CD4(+) T cells of patients in whom viraemia was fully suppressed by antiretroviral therapy, and directly studied the effect of VOR on this latent reservoir. In each of eight patients, a single dose of VOR increased both biomarkers of cellular acetylation, and simultaneously induced an increase in HIV RNA expression in resting CD4(+) cells (mean increase, 4.8-fold). This demonstrates that a molecular mechanism known to enforce HIV latency can be therapeutically targeted in humans, provides proof-of-concept for histone deacetylase inhibitors as a therapeutic class, and defines a precise approach to test novel strategies to attack and eradicate latent HIV infection directly.
Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/crescimento & desenvolvimento , Ácidos Hidroxâmicos/farmacologia , Latência Viral/efeitos dos fármacos , Acetilação/efeitos dos fármacos , Biomarcadores/metabolismo , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/virologia , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Infecções por HIV/sangue , HIV-1/genética , Inibidores de Histona Desacetilases/administração & dosagem , Inibidores de Histona Desacetilases/efeitos adversos , Inibidores de Histona Desacetilases/farmacologia , Histonas/efeitos dos fármacos , Histonas/metabolismo , Humanos , Ácidos Hidroxâmicos/administração & dosagem , Ácidos Hidroxâmicos/efeitos adversos , Provírus/efeitos dos fármacos , Provírus/genética , Provírus/crescimento & desenvolvimento , RNA Viral/biossíntese , RNA Viral/sangue , Medição de Risco , Regulação para Cima/efeitos dos fármacos , Viremia/tratamento farmacológico , Viremia/virologia , VorinostatRESUMO
Human immunodeficiency virus (HIV) infection of the central nervous system (CNS) is a significant cause of morbidity. The requirements for HIV adaptation to the CNS for neuropathogenesis and the value of CSF virus as a surrogate for virus activity in brain parenchyma are not well established. We studied 18 HIV-infected subjects, most with advanced immunodeficiency and some neurocognitive impairment but none with evidence of opportunistic infection or malignancy of the CNS. Clonal sequences of C2-V3 env and population sequences of pol from HIV RNA in cerebrospinal fluid (CSF) and plasma were correlated with clinical and virologic variables. Most (14 of 18) subjects had partitioning of C2-V3 sequences according to compartment, and 9 of 13 subjects with drug resistance exhibited discordant resistance patterns between the two compartments. Regression analyses identified three to seven positions in C2-V3 that discriminated CSF from plasma HIV. The presence of compartmental differences at one or more of the identified positions in C2-V3 was highly associated with the presence of discordant resistance (P = 0.007), reflecting the autonomous replication of HIV and the independent evolution of drug resistance in the CNS. Discordance of resistance was associated with severity of neurocognitive deficits (P = 0.07), while low nadir CD4 counts were linked both to the severity of neurocognitive deficits and to discordant resistance patterns (P = 0.05 and 0.09, respectively). These observations support the study of CSF HIV as an accessible surrogate for HIV virions in the brain, confirm the high frequency of discordant resistance in subjects with advanced disease in the absence of opportunistic infection or malignancy of the CNS, and begin to identify genetic patterns in HIV env associated with adaptation to the CNS.
Assuntos
Líquido Cefalorraquidiano/virologia , Produtos do Gene env/genética , Produtos do Gene pol/genética , HIV-1/classificação , RNA Viral/sangue , Análise de Sequência de DNA , Complexo AIDS Demência/tratamento farmacológico , Complexo AIDS Demência/virologia , Sequência de Aminoácidos , Fármacos Anti-HIV/farmacologia , Fármacos Anti-HIV/uso terapêutico , Farmacorresistência Viral , Produtos do Gene env/química , Produtos do Gene pol/química , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/genética , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/genética , Humanos , Dados de Sequência Molecular , Testes Neuropsicológicos , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Filogenia , Falha de TratamentoRESUMO
Viral replication and latently infected cellular reservoirs persist in HIV-infected patients achieving undetectable plasma virus levels with potent antiretroviral therapy. We exploited a predictable drug resistance mutation in the HIV reverse transcriptase to label and track cells infected during defined intervals of treatment and to identify cells replenished by ongoing replication. Decay rates of subsets of latently HIV-infected cells paradoxically decreased with time since establishment, reflecting heterogeneous lymphocyte activation and clearance. Residual low-level replication can replenish cellular reservoirs; however, it does not account for prolonged clearance rates in patients without detectable viremia. In patients receiving potent antiretroviral therapy, the latent pool has a heterogeneous and dynamic composition that comprises a progressively increasing proportion of stable lymphocytes. Eradication will not be achieved with complete inhibition of viral replication alone.
Assuntos
Infecções por HIV/sangue , Infecções por HIV/virologia , Linfócitos/patologia , Linfócitos/virologia , Terapia Antirretroviral de Alta Atividade , Sobrevivência Celular , DNA Viral/sangue , DNA Viral/genética , Infecções por HIV/tratamento farmacológico , Transcriptase Reversa do HIV/genética , HIV-1/genética , HIV-1/isolamento & purificação , HIV-1/fisiologia , Humanos , Mutação Puntual , Fatores de Tempo , Viremia/sangue , Viremia/virologia , Replicação ViralRESUMO
Although viral propagation is a localized process, mathematical models of viral replication kinetics have been limited to systems of ordinary differential equations describing spatially averaged behavior. In this paper, we introduce a cellular automaton model of viral propagation based on the known biophysical properties of HIV. In particular, we include the competition between viral lability and Brownian motion. The model predicts three testable effects not present in previous descriptions. First, we find a profound dependence of viral infectivity on cell concentration; virion instability decreases infectivity more than 100-fold under typical experimental conditions, resulting in misleading estimates of the number of infectious particles. Second, we find that, in a large parameter regime, infection extinguishes itself due to insufficient target cell replenishment. Finally, we find that propagation is limited by viral stability at low cell density and by geometry at high cell density. The geometry-limited regime can be modulated by downregulation of CD4. These different properties are analysed quantitatively and compared with previous experimental results.