Details

Autor(en) / Beteiligte

• dos Santos, Ana Catarina Taborda Godinho

Titel

Functional Aspects of New Helper Factors for HIV Replication

Ort / Verlag

ProQuest Dissertations & Theses

Erscheinungsjahr

2010

Quelle

ProQuest Dissertations & Theses A&I

Beschreibungen/Notizen

• Human immunodeficiency virus (HIV) depends on the host cell machinery to complete its life cycle. Several host proteins may help the virus to replicate and others have the ability to suppress its replication. These helper and restriction factors might be involved in many different pathways, such as RIG-I like helicases (RLH) signaling or microRNA (miRNA)-mediated silencing pathways, or could be a member of a specific group of proteins, like kinases and phosphatases. Here, we conducted a shRNA screen focused on innate antiviral defenses. Our study discovered 4 factors involved in HIV-1 replication: two participate in miRNA silencing, RNASEN and TNRC6A; and two proteins are regulators of RLH signaling pathway, ISG15 and OTUD5. RNASEN and ISG15 showed a helper factor nature regarding HIV-1, while TNRC6A and OTUD5 appear to have a restriction effect in HIV-1 replication. We also proceeded to the characterization of previously identified helper factors in other shRNA screen performed by Rato et al. For this purpose, we evaluated the effect of 13 proteins from the 14 identified in HIV-2 cycle, which exhibited a similar outcome from the one observed in HIV-1. From all kinases and phosphatases identified, we observed that one protein, CIB2, when overexpressed led to an enhanced LTR-driven expression, suggesting a role for CIB2 in HIV-1-LTR transcription. Moreover, we assessed that two of the identified proteins, SGK and CIB2, are important in HIV-1 entry, since their knockdown reduces the number of fusion events. In conclusion, this study highlights the power of small scale RNAi screens, providing new insights for the complex host-HIV interactions and instigating new possibilities for antiviral strategies.