HLA-G DNA sequence variants and risk of perinatal HIV-1 transmission

Background  

HLA-G gene is a non-classical MHC class 1 molecule that is highly expressed in the trophoblast at the maternal-fetal interface. In an attempt to elucidate possible immunological mechanisms facilitating protection of infants born to human immunodeficiency virus type (HIV-1) infected mothers, we have been studying genetic variations in the coding and untranslated regions of HLA-G antigen between HIV-1-infected mothers and their infected or uninfected infants. This study investigated whether HLA-G DNA sequence variants are associated with perinatal HIV-1 transmission.     

The identification of unique serum proteins of HIV-1 latently infected long-term non-progressor patients

Background  

The search for disease biomarkers within human peripheral fluids has become a favorable approach to preventative therapeutics throughout the past few years. The comparison of normal versus disease states can identify an overexpression or a suppression of critical proteins where illness has directly altered a patient's cellular homeostasis. In particular, the analysis of HIV-1 infected serum is an attractive medium with which to identify altered protein expression due to the ease and non-invasive methods of collecting samples as well as the corresponding insight into the in vivo interaction of the virus with infected cells/tissue. The utilization of proteomic techniques to globally identify differentially expressed serum proteins in response to HIV-1 infection is a significant undertaking that is complicated due to the innate protein profile of human serum.     

Non-productive HIV-1 infection of human glomerular and urinary podocytes

Podocyte damage induced by HIV-1 is critical to the pathogenesis of HIV-1 associated nephropathy (HIVAN) and is believed to result from productive replication of the virus. Here we demonstrate that HIV-1 readily enters human podocytes by a dynamin-mediated endocytosis but does not establish productive infection. We provide evidence suggesting that viral nucleic acids and proteins detected in podocytes are delivered by viral particles internalized by the cells. Endocytosed HIV-1 is only transiently harbored by podocytes and is subsequently released to the extracellular milieu as fully infectious virus. Similarly, primary podocytes established from normal human urine do not support productive infection by HIV-1 but sustain replication of VSV-G pseudotyped virus that bypasses HIV-1 entry receptors. Moreover, transfected podocytes expressing CD4 and CXCR4 receptors support productive replication of HIV-1. This further confirms that lack of HIV-1 entry receptors is the major barrier preventing productive infection of podocytes in vitro.     

Human hepatoma cells transmit surface bound HIV-1 to CD4 T cells through an ICAM-1/LFA-1-dependent mechanism

Background

During the viremic phase of human immunodeficiency virus type-1 (HIV-1) infection, hepatocytes are likely to be constantly exposed to circulating virions. Knowing that a contact between hepatocytes and CD4⁺ T lymphocytes is favoured by the local slow blood flow present within the liver, we hypothesize that hepatic cells can act as a viral reservoir and thus contribute to HIV-1 propagation.

Results

We report that human hepatoma cells bind and internalize HIV-1 particles. Infection of CD4⁺ T cells was found to be much more efficient following a contact with virus-loaded hepatocytes than with cell-free virus. Additional studies suggest that infection of CD4⁺ T cells in trans with hepatocytes carrying virus is primarily due to surface bound HIV-1 particles and relies on LFA-1/ICAM-1 interactions.

Conclusion

This work represents the first demonstration by which circulating CD4⁺ T cells can be potentially infected with HIV-1 through a contact with hepatocytes in the liver.     

HIV-1 resistance conferred by siRNA cosuppression of CXCR4 and CCR5 coreceptors by a bispecific lentiviral vector

Background  

RNA interference (RNAi) mediated by small interfering RNAs (siRNAs) has proved to be a highly effective gene silencing mechanism with great potential for HIV/AIDS gene therapy. Previous work with siRNAs against cellular coreceptors CXCR4 and CCR5 had shown that down regulation of these surface molecules could prevent HIV-1 entry and confer viral resistance. Since monospecific siRNAs targeting individual coreceptors are inadequate in protecting against both T cell tropic (X4) and monocyte tropic (R5) viral strains simultaneously, bispecific constructs with dual specificity are required. For effective long range therapy, the bispecific constructs need to be stably transduced into HIV-1 target cells via integrating viral vectors.     

CNS Persistence of HIV-1 in Children: the Untapped Reservoir

Purpose of Review

The central nervous system (CNS) represents a potential HIV-1 reservoir that may need to be specifically targeted by remission strategies. Perinatally HIV-1-infected children and youth are exposed to HIV-1 at a critical period of brain development. This review summarizes the current literature regarding HIV-1 and the CNS in perinatal infection.

Recent Findings

HIV-1-associated encephalopathy is prevalent with perinatal infection and neurocognitive impairment persists even following antiretroviral treatment (ART)-mediated suppression of viremia. Compartmentalization of HIV-1 between plasma and CSF of ART-naïve, perinatally infected children suggests the presence of a CNS reservoir; however, similar studies have not yet been conducted with ART suppression. CSF viral escape where CSF and plasma virus concentrations are discordant has been reported in this population, but larger studies with well-defined virologic and immunologic parameters are needed.

Summary

A better understanding of HIV-1 persistence in the CNS with perinatal infection is essential for improving long-term neurocognitive outcomes and for designing strategies to induce HIV-1 remission in this population.

     

Antioxidant protection from HIV-1 gp120-induced neuroglial toxicity

Background  

The pathogenesis of HIV-1 glycoprotein 120 (gp120) associated neuroglial toxicity remains unresolved, but oxidative injury has been widely implicated as a contributing factor. In previous studies, exposure of primary human central nervous system tissue cultures to gp120 led to a simplification of neuronal dendritic elements as well as astrocytic hypertrophy and hyperplasia; neuropathological features of HIV-1-associated dementia. Gp120 and proinflammatory cytokines upregulate inducible nitric oxide synthase (iNOS), an important source of nitric oxide (NO) and nitrosative stress. Because ascorbate scavenges reactive nitrogen and oxygen species, we studied the effect of ascorbate supplementation on iNOS expression as well as the neuronal and glial structural changes associated with gp120 exposure.     

Reduction of the HIV-1 reservoir in resting CD4+ T-lymphocytes by high dosage intravenous immunoglobulin treatment: a proof-of-concept study

Background  

The latency of HIV-1 in resting CD4⁺ T-lymphocytes constitutes a major obstacle for the eradication of virus in patients on antiretroviral therapy (ART). As yet, no approach to reduce this viral reservoir has proven effective.     

Characterization of Gp41 Polymorphisms in the Fusion Peptide Domain and T-20 (Enfuvirtide) Resistance-Associated Regions in Korean HIV-1 Isolates

HIV-1 gp41 is an envelope protein that plays an essential role in virus entry. The mutation of gp41 affects HIV-1 entry and susceptibility to the fusion inhibitor T-20. Therefore, we analyzed the natural polymorphism of gp41 of 163 HIV-1 isolates from T-20-naïve Koreans infected with HIV-1. This study of gp41 polymorphisms showed that insertions in the fourth threonine (74.8%) and L7M substitutions (85.3%) were more frequent in the fusion peptide motif in Korean HIV-1 isolates compared with those from other countries. Minor T-20 resistance mutations such as L45M (1.2%), N126K (1.2%), and E137K (6.7%) were detected, but the critical T-20 resistance mutations were not detected in the gp41 HR1 and HR2 regions. In addition, the N42S mutation (12.9%) associated with T-20 hypersusceptibility was detected at a high frequency. These results may serve as useful data for studies considering T-20 for use in the development of a more effective anti-retroviral treatment in Korea.

Graphical Abstract

相似文献   

Molecular Signatures of HIV-1 Envelope Associated with HIV-Associated Neurocognitive Disorders

Purpose of Review

The HIV-1 envelope gene (env) has been an intense focus of investigation in the search for genetic determinants of viral entry and persistence in the central nervous system (CNS).

Recent Findings

Molecular signatures of CNS-derived HIV-1 env reflect the immune characteristics and cellular constraints of the CNS compartment. Although more readily found in those with advanced HIV-1 and HIV-associated neurocognitive disorders (HAND), molecular signatures distinguishing CNS-derived quasispecies can be identified early in HIV-1 infection, in the presence or absence of combination antiretroviral therapy (cART), and are dynamic. Amino acid signatures of CNS-compartmentalization and HAND have been identified across populations. While some significant overlap exists, none are universal.

Summary

Detailed analyses of CNS-derived HIV-1 env have allowed researchers to identify a number of molecular determinants associated with neuroadaptation. Future investigations using comprehensive cohorts and longitudinal databases have the greatest potential for the identification of robust, validated signatures of HAND in the cART era.

     

HIV-1 gp120 Accelerates Fas-Mediated Activation-Induced Human Lamina Propria T Cell Apoptosis

Intestinal mucosa represents an important portal of entry of HIV and a site of virus reservoir and active replication. Recently, in HIV patients, an early depletion of intestinal lamina propria T lymphocytes (LPT) has been described. HIV-1 gp120 has been demonstrated to promote apoptosis in noninfected isolated peripheral blood T cells, therefore we investigated whether gp120 modulates apoptosis of normal human intestinal lamina propria T cells. Purified T cells were obtained by immunomagnetic negative selection from human lamina propria mononuclear cells isolated from surgical specimens by enzymatic procedure. Cells were incubated with or without recombinant gp120 (10 g/ml) and cultured either in the absence of any stimulus or in the presence of plate-bound anti-CD3 Ab (OKT3) or soluble anti-CD2 Ab (T11₂ + T11₃). Apoptosis was assessed by flow cytometric analysis after propidium iodide staining. We demonstrated that preincubation of normal LPT cells with HIV-1 gp120 accelerates the apoptosis observed during CD2-pathway stimulation of LPT cells. This process is mediated by Fas/Fas ligand interaction and related to an increased induction of Fas ligand mRNA by gp120. Therefore HIV-1 gp120 could contribute to the depletion of noninfected LPT cells inducing a premature cell death.     

Differential activity of candidate microbicides against early steps of HIV-1 infection upon complement virus opsonization

Background  

HIV-1 in genital secretions may be opsonized by several molecules including complement components. Opsonized HIV-1 by complement enhances the infection of various mucosal target cells, such as dendritic cells (DC) and epithelial cells.     

Resistance of HIV-1 to the broadly HIV-1-neutralizing, anti-carbohydrate antibody 2G12

The 2G12 mAb inhibits the infection of HIV-1 laboratory-adapted viruses at 50% inhibitory concentrations (IC(50)) ranging from 0.02 to 0.2 microg/ml when evaluated in different cell-types. However, isolates from various HIV-1 subtypes (such as clade C, D, A/E, F and group O) were not inhibited by 2G12 mAb (IC(50) >20 microg/ml). 2G12 mAb pressure in HIV-1 IIIB- and NL4.3-infected T cell cultures selected for resistant viruses containing only few (1 to 3 N-glycosylation) deletions in gp120. The 2G12-resistant viruses keep their full sensitivity to various mannose-specific lectins and other known HIV entry inhibitors. Moreover, we observed that the NL4.3-2G12-resistant virus, with the N295K mutation in gp120, became significantly more sensitive to several mannose-specific lectins. This is, to our knowledge, the first report showing that a resistant virus generated in vitro against a neutralizing mAb and containing a mutation in gp120, has increased sensitivity to another class of HIV entry inhibitors.     

A genotypic HIV-1 proviral DNA coreceptor tropism assay: characterization in viremic subjects

Background

Amyloid fibrils such as Semen-Derived Enhancer of Viral Infection (SEVI) or amyloid-β-peptide (Aβ) enhance HIV-1 attachment and entry. Inhibitors destroying or converting those fibrils into non-amyloidogenic aggregates effectively reduce viral infectivity. Thus, they seem to be suitable as therapeutic drugs expanding the current HIV-intervening repertoire of antiretroviral compounds.

Findings

In this study, we demonstrate that the small D-amino acid peptide D3, which was investigated for therapeutic studies on Alzheimer’s disease (AD), significantly reduces both SEVI and Aβ fibril boosted infectivity of HIV-1.

Conclusions

Since amyloids could play an important role in the progression of AIDS dementia complex (ADC), the treatment of HIV-1 infected individuals with D3, that inhibits Aβ fibril formation and converts preformed Aβ fibrils into non-amyloidogenic and non-fibrillar aggregates, may reduce the vulnerability of the central nervous system of HIV patients for HIV associated neurological disorders.     

Endotoxin-induced cytokine and chemokine expression in the HIV-1 transgenic rat

Background  

Repeated exposure to a low dose of a bacterial endotoxin such as lipopolysaccharide (LPS) causes immune cells to become refractory to a subsequent endotoxin challenge, a phenomenon known as endotoxin tolerance (ET). During ET, there is an imbalance in pro- and anti-inflammatory cytokine and chemokine production, leading to a dysregulated immune response. HIV-1 viral proteins are known to have an adverse effect on the immune system. However, the effects of HIV-1 viral proteins during ET have not been investigated.     

A rapid RT-PCR assay for the detection of HIV-1 in human plasma specimens

Introduction

The CDC estimates that there are currently over 1 million people living with human immunodeficiency virus (HIV-1) in the United States, with new cases increasing by approximately 50,000 each year. HIV-1 consists of four distinct groups: the major M group, and the rare N, O, and P groups, each comprising of various subtypes. Without proper care, HIV-1 can lead to cardiovascular, kidney, and liver diseases, cancer, and rapid progression into acquired immune deficiency syndrome (AIDS). Here, we describe a novel, rapid, and highly sensitive assay for the detection of HIV-1 using intercalating dye based RT-PCR and melt curve analysis.

Materials and methods

We designed an RT-PCR assay for the detection of the major M subtypes in addition to the rare (O, N, and P) HIV-1 groups, as well as an extraction/RT-PCR control, using melt curve analysis. Viral RNA was extracted using the automated Qiagen EZ1 robotic system (Qiagen, Valencia, CA). To establish the limit of detection (LOD) for this assay, we diluted the AcroMetrix HIV-1 panel (LifeTechnologies, Grand Island, NY) to concentrations ranging from 25 to 500 copies/ml. Armored RNA® BCR/ABL b3/a2 (Asuragen, Austin, Texas) was used as our extraction and RT-PCR control. Specificity and accuracy were assessed by testing plasma specimens from 48 anonymized patients negative for HIV-1.

Results

This assay has a turnaround time of less than 2.5 h and has a limit of detection of 50 copies/ml of plasma. Our assay also demonstrated 100% concordance with 53 previously quantified plasma patient specimens, including 48 negative samples and 5 positive samples. HIV-1 and our extraction/RT-PCR control were consistently identified at 79 °C and 82.5 °C, respectively.

Conclusions

We developed a comprehensive, easy to use assay for the detection of HIV-1 in human plasma. Our assay combines a rapid and cost-effective method for molecular diagnostics with the versatility necessary for widespread laboratory use. These performance characteristics make this HIV-1 detection assay highly suitable for use in a clinical laboratory.     

Evaluation of the NucliSens EasyQ HIV-1 v1.1 and RealTime HIV-1 kits for quantitation of HIV-1 RNA in plasma

Human immunodeficiency virus type-1 (HIV-1) RNA viral load is an important biomarker to evaluate the therapeutic efficacy of antiretroviral drugs and to monitor disease progression in HIV-infected individuals. We compared HIV-1 RNA quantitation between two different kits, the NucliSens EasyQ^® HIV-1 v1.1 (EasyQ, bioMérieux) and RealTime HIV-1 (RealTime, Abbott), using HIV-1 RNA quality control (QC) materials, cell-cultivated viruses, and the plasma samples of 104 patients with HIV. Correlation between the two kits for HIV RNA-1 quantitation with clinical samples was high (R = 0.91). Based on results obtained with quality control standards, the reproducibility of the RealTime kit was higher than the EasyQ kit: the viral load value and coefficient of variation of each kit was 4.11 ± 0.136 and 3.3% for EasyQ and 3.55 ± 0.042 and 1.2% for RealTime, respectively (P < 0.002).This is the first comparative analysis of the detection limit and reproducibility of two different quantitation kits using clinical plasma samples from Korean HIV-1-infected patients. It will serve a useful reference to determine correction values for each HIV-1 RNA quantitation kits and to choose an appropriate assay kit for each laboratory.