Different Patterns of HIV-1 Replication in MACROPHAGES is Led by Co-Receptor Usage.

To enter the target cell, HIV-1 binds not only CD4 but also a co-receptor β-chemokine receptor 5 (CCR5) or α chemokine receptor 4 (CXCR4). Limited information is available on the impact of co-receptor usage on HIV-1 replication in monocyte-derived macrophages (MDM) and on the homeostasis of this important cellular reservoir. Replication (measured by p24 production) of the CCR5-tropic 81A strain increased up to 10 days post-infection and then reached a plateau.

Effects of Amprenavir on HIV-1 Maturation, Production and Infectivity Following Drug Withdrawal in Chronically-Infected Monocytes/Macrophages.

A paucity of information is available on the activity of protease inhibitors (PI) in chronically-infected monocyte-derived macrophages (MDM) and on the kinetics of viral-rebound after PI removal in vitro. To fill this gap, the activity of different concentrations of amprenavir (AMP) was evaluated in chronically-infected MDM by measuring p24-production every day up to 12 days after drug administration and up to seven days after drug removal. Clinically-relevant concentrations of AMP (4 and 20 μM) drastically decreased p24 amount released from chronically-infected MDM from Day 2 up to Day 12 after drug administration.

Novel HBsAg mutations correlate with hepatocellular carcinoma, hamper HBsAg secretion and promote cell proliferation in vitro.

Background: An impaired HBsAg-secretion can increase HBV oncogenic-properties. Here, we investigate genetic-determinants in HBsAg correlated with HBV-induced hepatocellular carcinoma (HCC), and their impact on HBsAg-secretion and cell-proliferation.

Methods: This study included 128 chronically HBV-infected patients: 23 with HCC (73.

Multiple Hepatitis B Virus (HBV) Quasispecies and Immune-Escape Mutations Are Present in HBV Surface Antigen and Reverse Transcriptase of Patients With Acute Hepatitis B.

Background: This study characterizes and defines the clinical value of hepatitis B virus (HBV) quasispecies with reverse transcriptase and HBV surface antigen (HBsAg) heterogeneity in patients with acute HBV infection.

Methods: Sixty-two patients with acute HBV infection (44 with genotype D infection and 18 with genotype A infection) were enrolled from 2000 to 2010. Plasma samples obtained at the time of the first examination were analyzed by ultradeep pyrosequencing.

Thymosin α 1 potentiates the release by CD8(+) cells of soluble factors able to inhibit HIV-1 and human T lymphotropic virus 1 infection in vitro.

Background: Thymosin α-1 (Tα1) exploits a specific action on lymphoid cells and is able to induce in peripheral blood mononuclear cells (PBMCs) a strong transcriptional response. CD8 antiviral factor activity plays a role in the control or prevention of HIV-1 infection by a non-cytolytic mechanism. The ability of Tα1 to modulate the release of antiretroviral soluble factors by CD8(+) cells was investigated.

Specific mutations in the C-terminus domain of HBV surface antigen significantly correlate with low level of serum HBV-DNA in patients with chronic HBV infection.

Background: To define HBsAg-mutations correlated with different serum HBV-DNA levels in HBV chronically-infected drug-naive patients.

Methods: This study included 187 patients stratified into the following ranges of serum HBV-DNA:12-2000 IU/ml, 2000-100,000 IU/ml, and >100,000 IU/ml. HBsAg-mutations were associated with HBV-DNA levels by applying a Bayesian-Partitional-Model and Fisher-exact test.

Hepatitis B surface antigen genetic elements critical for immune escape correlate with hepatitis B virus reactivation upon immunosuppression.

Unlabelled: Hepatitis B virus (HBV) reactivation during immunosuppression can lead to severe acute hepatitis, fulminant liver failure, and death. Here, we investigated hepatitis B surface antigen (HBsAg) genetic features underlying this phenomenon by analyzing 93 patients: 29 developing HBV reactivation and 64 consecutive patients with chronic HBV infection (as control). HBsAg genetic diversity was analyzed by population-based and ultradeep sequencing (UDS).

Comparative replication capacity of raltegravir-resistant strains and antiviral activity of the new-generation integrase inhibitor dolutegravir in human primary macrophages and lymphocytes.

Objectives: To evaluate the replication capacity and phenotypic susceptibility to dolutegravir and raltegravir of wild-type and raltegravir-resistant HIV-1 strains in several cellular systems.

Methods: The antiviral activities of dolutegravir and raltegravir were evaluated in human primary monocyte-derived macrophages (MDMs), peripheral blood mononuclear cells (PBMCs) and C8166 T lymphocytic cells. The following raltegravir resistance mutations were analysed: N155H, Y143C, N155H + Y143C and G140S+Q148H.

Nucleotide polymorphisms in the 5'-UTR region of HCV can affect the ability of two widely used assays to assign an HCV genotype.

Determination of hepatitis C virus genotype is crucial for establishing the duration of antiviral therapy and predicts response to treatment. In this study, consecutive serum samples collected from two patients with chronic hepatitis C infection were tested by two assays used widely, the Abbott RealTime HCV Genotype II and the Versant HCV Genotype 2.0 assays, in order to assign a genotype to the virus.

Performance of genotypic tropism testing on proviral DNA in clinical practice: results from the DIVA study group.

Objective: The DIVA study is aimed at setting up a standardized genotypic tropism-testing on proviral-DNA for the routine clinical diagnostic-laboratory.

Methods: Twelve local centres and 5 reference centres (previously cross-validated) were identified. For inter-center validation-procedure, 60 peripheral-blood mononuclear cells (PBMCs) aliquots from 45 HAART-treated patients were randomly chosen for population V3 sequencing on proviral-DNA at local HIV centre and at reference-laboratory.

Comparative antiviral activity of integrase inhibitors in human monocyte-derived macrophages and lymphocytes.

The activity of raltegravir and 4 other integrase inhibitors (MK-2048, L870,810, IN2, and IN5) was investigated in primary human macrophages, PBMC and C8166-lymphocytic T cells, in order to determine their relative potency and efficacy in different cellular systems of HIV infection. Raltegravir showed better protective efficacy in all cell types; MK-2048, L870,810 and IN5 showed a potent anti-HIV-1 activity in macrophages, while in lymphocytes only MK-2048 and L870,810 showed an inhibitory effect comparable to raltegravir. IN2 was a poorly effective anti-HIV-1 compound in all cellular systems.

Secondary integrase resistance mutations found in HIV-1 minority quasispecies in integrase therapy-naive patients have little or no effect on susceptibility to integrase inhibitors.

The goal of this study was to explore the presence of integrase strand transfer inhibitor (InSTI) resistance mutations in HIV-1 quasispecies present in InSTI-naïve patients and to evaluate their in vitro effects on phenotypic susceptibility to InSTIs and their replication capacities. The RT-RNase H-IN region was PCR amplified from plasma viral RNA obtained from 49 HIV-1 subtype B-infected patients (21 drug naïve and 28 failing highly active antiretroviral therapy [HAART] not containing InSTIs) and recombined with an HXB2-based backbone with RT and IN deleted. Recombinant viruses were tested against raltegravir and elvitegravir and for replication capacity.

Apoptosis and telomeres shortening related to HIV-1 induced oxidative stress in an astrocytoma cell line.

Background: Oxidative stress plays a key role in the neuropathogenesis of Human Immunodeficiency Virus-1 (HIV-1) infection causing apoptosis of astroglia cells and neurons. Recent data have shown that oxidative stress is also responsible for the acceleration of human fibroblast telomere shortening in vitro. In the present study we analyzed the potential relations occurring between free radicals formation and telomere length during HIV-1 mediated astroglial death.

HIV-1-associated dementia during HAART therapy.

Human immunodeficiency virus (HIV-1) is the responsible agent of acquired immunodeficiency syndrome (AIDS), a multi system disorder including the central nervous system (CNS). The CNS is an immunological privileged site providing a sanctuary and reservoir for HIV-1. Monocytes derived macrophages (MDM) and microglia play a critical role in the development of HIV-associated dementia (HAD).

Profound anti-HIV-1 activity of DAPTA in monocytes/macrophages and inhibition of CCR5-mediated apoptosis in neuronal cells.

Monocytes/macrophages (M/M) are strategic reservoirs of HIV-1, spreading the virus to other cells and inducing apoptosis in T-lymphocytes, astrocytes and neurons. M/M are commonly infected by R5 HIV-1 strains, which use the chemokine receptor CCR5. D-Ala-peptide T-amide (DAPTA), or Peptide T, named for its high threonine content (ASTTTNYT), is a synthetic peptide comprised of eight amino acids (185-192) of the gp120 V2 region and functions as a viral entry inhibitor by targeting selectively CCR5.

The contribution of peroxynitrite generation in HIV replication in human primary macrophages.

Background: Monocytes/Macrophages (M/M) play a pivotal role as a source of virus during the whole course of HIV-1 infection. Enhanced oxidative stress is involved in the pathogenesis of HIV-1 infection. HIV-1 regulatory proteins induce a reduction of the expression and the activity of MnSOD, the mitochondrial isoform leading to a sustained generation of superoxide anions and peroxynitrite that represent important mediators of HIV-1 replication in M/M.

Telomerase activity, hTERT expression, and phosphorylation are downregulated in CD4(+) T lymphocytes infected with human immunodeficiency virus type 1 (HIV-1).

Human immunodeficiency virus type 1 (HIV-1) infection is characterized by a progressive decrease of CD4(+) T cells accompanied by other immune dysfunctions. Telomerase is transiently activated in lymphocytes during activation and is able to compensate for the progressive telomeric loss that occurs at each cell division, contributing to ensure the telomere length necessary for multiple proliferative events. The effect of HIV-1 infection on telomerase activity and on the expression of some of the factors involved in its regulation in CD4(+) T cells was investigated.

Novel in vivo model for the study of human immunodeficiency virus type 1 transcription inhibitors: evaluation of new 6-desfluoroquinolone derivatives.

Two novel 6-desfluoroquinolone derivatives, HM-12 and HM-13, were evaluated for anti-human immunodeficiency virus (anti-HIV) activity in acutely, chronically, and latently HIV type 1 (HIV-1)-infected cell cultures and were found to behave as potent HIV-1 transcription inhibitors. In order to extend this result in vivo, we developed an artificial hu-SCID mouse model for HIV-1 latency based on SCID mice engrafted with latently HIV-1-infected promyelocytic OM-10.1 cells in which HIV-1 can be reactivated in vivo by the administration of human tumor necrosis factor alpha (hTNF-alpha).

Mechanisms underlying activity of antiretroviral drugs in HIV-1-infected macrophages: new therapeutic strategies.

Monocyte-derived macrophages (M/M) are considered the second cellular target of HIV-1 and a crucial virus reservoir. M/M are widely distributed in all tissues and organs, including the CNS, where they represent the most common HIV-infected cells. Differently from activated CD4+ T lymphocytes, M/M are resistant to the cytopathic effect of HIV and survive HIV infection for a long time.

Therapeutic strategies towards HIV-1 infection in macrophages.

It is widely recognized that macrophages (M/M) represent a crucial target of HIV-1 in the body and play a pivotal role in the pathogenic progression of HIV-1 infection. This strongly supports the clinical relevance of therapeutic strategies able to interfere with HIV-1 replication in M/M. In vitro studies showed that nucleoside analogue inhibitors of HIV-1 reverse transcriptase have potent antiviral activity in M/M, although the limited penetration of these compounds in sequestered body compartments and low phosphorylation ability of M/M, suggest that a phosphonate group linked to NRTIs may confer greater anti-HIV-1 activity in M/M.

Human immunodeficiency virus infection and acquired immunodeficiency syndrome dementia complex: role of cells of monocyte-macrophage lineage.

The entry of human immunodeficiency virus (HIV) into the central nervous system (CNS) causes both the establishment of a lifelong viral reservoir in the brain and symptoms of neurological dysfunction that have an AIDS dementia complex (ADC) clinical appearance. Neurological dysfunction in ADC patients still remains an unresolved problem. However, ADC pathogenesis may be a multistep process that starts with HIV invasion of CNS by crossing the blood-brain barrier (BBB).