RESUMEN
Once the human immunodeficiency virus (HIV) genome is inserted into the host genome, the virus cannot be removed, which results in latency periods and makes it difficult to eradicate. The majority of strategies to eradicate HIV have been based on preventing virus latency, thereby enabling antiretroviral drugs to act against HIV replication. Another innovative strategy is permanently silencing the integrated virus to prevent the spread of infection. Epigenetic processes are natural mechanisms that can silence viral replication. We describe a new chimeric protein (IN3b) that consists of a HIV-1 integrase domain, which recognises the HIV long terminal repeat (LTR) and the catalytic domain of DNA methyltransferase DNMT3b. Our objective was to silence HIV replication by the specific delivery of the catalytic methyltransferase domain to the LTR promoter to induce its methylation. We found that our IN3b chimeric protein was expressed in the nucleus and decreased LTR-associated HIV genome expression and HIV replication. Therefore, the IN3b chimeric protein may be an effective tool against HIV replication and maybe used in a new line of research to induce or maintain HIV latency.
Asunto(s)
ADN (Citosina-5-)-Metiltransferasas/metabolismo , Silenciador del Gen , Genoma Viral , Duplicado del Terminal Largo de VIH , Proteínas Recombinantes de Fusión/metabolismo , Dominio Catalítico , Núcleo Celular , ADN (Citosina-5-)-Metiltransferasas/genética , Metilación de ADN , Evaluación Preclínica de Medicamentos , Vectores Genéticos/genética , Vectores Genéticos/metabolismo , Células HEK293 , Integrasa de VIH/genética , Integrasa de VIH/metabolismo , VIH-1/fisiología , Humanos , Mutación Puntual , Regiones Promotoras Genéticas , Proteínas Recombinantes de Fusión/genética , Transcripción Genética , Transfección , Integración Viral , Latencia del Virus , Replicación Viral , ADN Metiltransferasa 3BRESUMEN
BACKGROUND: Lopinavir/ritonavir is a protease inhibitor (PI) that has shown great effectiveness as salvage therapy in PI-experienced HIV-infected children. OBJECTIVES: To study whether mutations in the HIV-1 protease gene can reliably predict virological responses to salvage therapy with lopinavir/ritonavir in HIV-infected children. PATIENTS AND METHODS: We carried out a prospective study in 56 HIV-infected children. PI-associated resistance mutations were determined by genotypic testing and were scored according to the IAS-USA guidelines 2005. RESULTS: Children with a 'lopinavir mutation score' (LMS) > or = 6 had a negative association for achieving viral load (VL) control [undetectable viral load (uVL) < or = 400 copies/mL] and maintaining uVL for at least 6 months. Moreover, children with protease-associated mutations (PRAMs) > or = 2 had a negative association for achieving VL control but not for maintaining uVL for at least 6 months. The relative proportion (RP) to uVL was 0.32 (CI95%: 0.16; 0.33; P = 0.002) in children with I54V (46% of total) and 0.48 (CI95%: 0.24; 0.97; P = 0.041) in children with V82A/F (52% of total). Children with I54V and V82A/F had higher prevalence of lopinavir-associated resistance mutations and showed RP of 0.36 (CI95%: 0.17; 0.76; P = 0.007) for achieving uVL. CONCLUSIONS: LMS and PRAMs in HIV-infected children were associated with virological failure in pre-treated HIV-infected children on salvage therapy with lopinavir/ritonavir. Moreover, I54V and V82A/F led to the poorest virological response.