HIV-1 Tat endocytosis and retention in endolysosomes affects HIV-1 Tat-induced LTR transactivation in astrocytes.
FASEB J
; 36(3): e22184, 2022 03.
Article
en En
| MEDLINE
| ID: mdl-35113458
ABSTRACT
The presence of latent HIV-1 reservoirs in the periphery and brain represents a major obstacle to curing HIV-1 infection. As an essential protein for HIV-1 viral replication, HIV-1 Tat, mostly intracellular, has been implicated in latent HIV-1 infection. From HIV-1 infected cells, HIV-1 Tat is actively secreted and bystander cells uptake the released Tat whereupon it is endocytosed and internalized into endolysosomes. However, to activate the HIV-1 LTR promoter and increase HIV-1 replication, HIV-1 Tat must first escape from the endolysosomes and then enter the nucleus. Here, we tested the hypothesis that HIV-1 Tat can accumulate in endolysosomes and contribute to the activation of latent HIV-1 in astrocytes. Using U87MG astrocytoma cells expressing HIV-1 LTR-driven luciferase and primary human astrocytes we found that exogenous HIV-1 Tat enters endolysosomes, resides in endolysosomes for extended periods of time, and induces endolysosome de-acidification as well as enlargement. The weak base chloroquine promoted the release of HIV-1 Tat from endolysosomes and induced HIV-1 LTR transactivation. Similar results were observed by activating endolysosome Toll-like receptor 3 (TLR3) and TLR7/8. Conversely, pharmacological block of TLRs and knocking down expression levels of TLR3 and TLR7, but not TLR8, prevented endolysosome leakage and attenuated HIV-1 Tat-mediated HIV-1 LTR transactivation. Our findings suggest that HIV-1 Tat accumulation in endolysosomes may play an important role in controlling HIV-1 transactivation.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Contexto en salud:
2_ODS3
Problema de salud:
2_enfermedades_transmissibles
Asunto principal:
Endosomas
/
Activación Transcripcional
/
Astrocitos
/
Duplicado del Terminal Largo de VIH
/
VIH-1
/
Endocitosis
/
Productos del Gen tat del Virus de la Inmunodeficiencia Humana
/
Lisosomas
Límite:
Humans
Idioma:
En
Revista:
FASEB J
Asunto de la revista:
BIOLOGIA
/
FISIOLOGIA
Año:
2022
Tipo del documento:
Article
País de afiliación:
Estados Unidos