Browsing by Author "Santa-Marta, M"
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- Camelized rabbit-derived VH single-domain Intrabodies Against vif strongly neutralize HIV-1 infectivityPublication . da Silva, FA; Santa-Marta, M; Freitas-Vieira, A; Mascarenhas, P; Barahona, I; Moniz-Pereira, J; Gabuzda, D; Goncalves, JWe recently developed a specific single-chain antibody from immunized rabbits to HIV-1 Vif protein that was expressed intracellularly and inhibited reverse transcription and viral replication. The Vif of HIV-1 overcomes the innate antiviral activity of a
- Functional analysis of vif protein shows less restriction of human immunodeficiency virus type 2 by APOBEC3GPublication . Ribeiro, AC; Silva, AME; Silva, AME; Santa-Marta, M; Pombo, A; Moniz-Pereira, J; Goncalves, J; Barahona, IViral infectivity factor (Vif) is one of the human immunodeficiency virus (HIV) accessory proteins and is conserved in the primate lentivirus group. This protein is essential for viral replication in vivo and for productive infection of nonpermissive cell
- Functional neutralization of HIV-1 Vif protein by intracellular immunization inhibits reverse transcription and viral replicationPublication . Goncalves, J; Silva, F; Freitas-Vieira, A; Santa-Marta, M; Malho, R; Yang, XY; Gabuzda, D; Barbas, CHuman immunodeficiency virus type 1 (HIV-1)-encoded Vif protein is important for viral replication and infectivity. Vif is a cytoplasmic protein that acts during virus assembly by an unknown mechanism, enhancing viral infectivity. The action of Vif in producer cells is essential for the completion of proviral DNA synthesis following virus entry. Therefore, Vif is considered to be an important alternative therapeutic target for inhibition of viral infectivity at the level of viral assembly and reverse transcription. To gain insight into this process, we developed a Vif-specific single-chain antibody and expressed it intracellularly in the cytoplasm. This intrabody efficiently bound Vif protein and neutralized its infectivity-enhancing function. Intrabody-expressing cells were shown to be highly refractory to challenge with different strains of HIV-1 and HIV-1-infected cells. Inhibition of Vif by intrabody expression in the donor cell produced viral particles that do not complete reverse transcription in the recipient cell. The anti-Vif scFv was shown to be specific for Vif protein because its function was observed only in nonpermissive cells (H9, CEM, and U38). Moreover, transduction of peripheral blood mononuclear cells with an HIV-derived retroviral vector expressing Vif intrabody was shown to confer resistance to laboratory-adapted and primary HIV strains. This study provides biochemical evidence for the role of Vif in the HrV-1 lifecycle and validates Vif as a target for the control of HIV-1 infection.
- Functional neutralization of HIV-1 Vif protein by intracellular immunization inhibits viral replicationPublication . Goncalves, J; Silva, F; Freitas-Vieira, A; Santa-Marta, M; Malho, R; Yang, X; Gabuzda, D; Barbas, CHuman immunodeficiency virus type 1 (HIV-1) encoded Vif protein is important for viral replication and infectivity. Therefore, Vif is considered to be an important alternative therapeutic target for inhibition of viral infectivity at the level of viral as
- HIV-1 Vif can directly inhibit apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G-mediated cytidine deamination by using a single amino acid interaction and without protein degradationPublication . Santa-Marta, M; da Silva, FA; Fonseca, AM; Goncalves, JThe human apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G (APOBEC3G), also known as CEM-15, is a host-cell factor involved in innate resistance to retroviral infection. HIV-1 viral infectivity factor (Vif) protein was shown to protect t
- Phosphorylation of a novel SOCS-box regulates assembly of the HIV-1 Vif-Cul5 complex that promotes APOBEC3G degradationPublication . Mehle, A; Goncalves, J; Santa-Marta, M; McPike, M; Gabuzda, DHIV-1 Vif (viral infectivity factor) protein overcomes the antiviral activity of the DNA deaminase APOBEC3G by targeting it for proteasomal degradation. We report here that Vif targets APOBEC3G for degradation by forming an SCF-like E3 ubiquitin ligase co