Current HIV Research - Volume 10, Issue 4, 2012

Tetherin (BST-2 or CD317) is an interferon-inducible cellular factor that prevents the detachment of enveloped viruses from infected cells. The primate lentiviruses have evolved different countermeasures to tetherin. The majority of SIVs use Nef to antagonize the tetherin proteins of their nonhuman primate hosts. However, due to the absence of sequences in human tetherin required for antagonism by Nef, HIV-1 Vpu and Read More

The interferon-inducible host restriction factor bone marrow stromal antigen 2 (BST-2/tetherin) blocks the release of human immunodeficiency virus type 1 (HIV-1) by directly cross-linking virions to the membrane of infected cells. This antiviral effect is counteracted by the HIV-1 accessory protein viral protein U (Vpu) through mechanisms that remain unclear. Accumulating evidence suggests that Vpu antagonizes BST-2 by r Read More

Tetherin is a type II membrane protein that bears a N-terminal transmembrane domain, an extracellular coiledcoil structure and a C-terminal GPI anchor. This unique topology allows tetherin to block the release of a wide range of enveloped viruses from the cell surface. In order to overcome this host restriction, viruses have evolved various counter measures. In the case of human immunodeficiency virus type 1 (HIV-1), the vi Read More

HIV-1 employs its structural proteins to orchestrate assembly and budding at the plasma membrane of host cells, which depends on numerous cellular factors. Although cells evolved interferon inducible restriction factors such as tetherin that act as a first line of defense, enveloped viruses, including HIV-1, developed countermeasures in the form of tetherin antagonists such as Vpu that decrease the effect of tetherin and per Read More

During evolution, pathogens have evolved strategies to counteract key cellular restriction mechanisms in order to efficiently invade target cells and fulfill essential steps of their replication cycle. Human Immunodeficiency Virus-1 and some Simian counterparts express a small multifunctional protein, Vpu, which influences viral replication. By acting as a multifunctional adapter, Vpu enhances viral particle release and infectivity. Read More

The cellular protein “Bone marrow stromal antigen 2” (BST2 also called Tetherin, CD317, HM1.24) was identified as a major mediator of the innate immune defense against the dissemination of enveloped viruses. BST2 was shown to physically trap the de novo formed viral particles at the surface of infected cells, thereby reducing viral release. Lentiviruses have evolved specific strategies to down-regulate the expression le Read More

Bone marrow stromal antigen 2 (BST-2) is a type II membrane protein with two targeting signals, one of which is located in the cytoplasmic domain and contains a non-canonical dual tyrosine-based motif responsible for its endocytosis from the plasma membrane, and the other is a C-terminal glycosylphosphatidylinositol anchor that facilitates its association with detergent-resistant membranes/lipid rafts and targeting to the api Read More

The HIV-1 accessory protein Vpu is emerging as a viral factor with a range of activities devoted to counteracting host innate immunity. Here, we review recent findings concerning the role of Vpu in hampering activation of cellular immune responses mediated by CD1d-restricted invariant natural killer T (iNKT) cells and natural killer (NK) cells. The two key findings are that Vpu interferes with CD1d expression and antigen pr Read More

Objective: The aim of the present study was to evaluate the virological response to a new antiretroviral treatment (ART2) after failure of a nonnucleoside reverse transcriptase inhibitor (NNRTI) plus two nucleoside reverse transcriptase inhibitors (NRTIs)-containing regimen. Design: Retrospective observational study based on the Italian ARCA cohort database. Adult patients were included if they had a virological failur Read More

Interleukin-7 (IL-7) is a cytokine that plays a critical role in T cell homeostasis by promoting proliferation and survival of mature T cells and also by enhancing thymic output for the generation of new T cells. IL-7 receptor expression and signaling function is perturbed in HIV infection and could contribute to disease pathogenesis. Even though highly active anti-retroviral therapy has markedly reduced morbidity and mortality in HI Read More

HIV clinical trials play an essential role in producing new HIV medications, developing guidelines for the appropriate timing of antiretroviral treatment, and evaluating behavioral interventions that aim to increase the quality of life of HIV-infected individuals. It is critical to have participation from all demographic groups, yet minorities are disproportionately underrepresented in HIV clinical research. This study as Read More

Objective: HIV-1-infected active drug users (ADU) obtain smaller clinical benefits with antiretroviral therapy (HAART) compared to non-ADU subjects with sexually-transmitted HIV-1 infection. Therefore treatment strategies are required to address the specific issues arising in this challenging scenario. We describe the effectiveness of HAART provided in a drug abuse outpatient treatment facility through a comprehensive integ Read More