Search

Venkata Subba Rao Atluri* Rahul Dev Jayant* Sudheesh Pilakka-Kanthikeel, Gabriella Garcia, Thangavel Samikkannu, Adriana Yndart, Ajeet Kaushik, Madhavan Nair Center for Personalized Nanomedicine, Department of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA *These authors contributed equally to this work Abstract: Although the introduction of antiretroviral therapy has reduced the prevalence of severe forms of neurocognitive disorders, human immunodeficiency virus (HIV)-1-associated neurocognitive disorders were observed in 50% of HIV-infected patients globally. The blood–brain barrier is known to be impermeable to most of antiretroviral drugs. Successful delivery of antiretroviral drugs into the brain may induce an inflammatory response, which may further induce neurotoxicity. Therefore, alternate options to antiretroviral drugs for decreasing the HIV infection and neurotoxicity may help in reducing neurocognitive impairments observed in HIV-infected patients. In this study, we explored the role of magnetic nanoparticle (MNP)-bound tissue inhibitor of metalloproteinase-1 (TIMP1) protein in reducing HIV infection levels, oxidative stress, and recovering spine density in HIV-infected SK-N-MC neuroblastoma cells. We did not observe any neuronal cytotoxicity with either the free TIMP1 or MNP-bound TIMP1 used in our study. We observed significantly reduced HIV infection in both solution phase and in MNP-bound TIMP1-exposed neuronal cells. Furthermore, we also observed significantly reduced reactive oxygen species production in both the test groups compared to the neuronal cells infected with HIV alone. To observe the effect of both soluble-phase TIMP1 and MNP-bound TIMP1 on spine density in HIV-infected neuronal cells, confocal microscopy was used. We observed significant recovery of spine density in both the test groups when compared to the cells infected with HIV alone, indicting the neuroprotective effect of TIMP1. Therefore, our results suggest that the MNP-bound TIMP1 delivery method across the blood–brain barrier can be used for reducing HIV infectivity in brain tissue and neuronal toxicity in HIV-infected patients. Keywords: HIV, neurocognitive disorders, TIMP1, magnetic nanoparticles, blood–brain barrier, neuroprotection

Upal Roy,1,* Hong Ding,1,* Sudheesh Pilakka-Kanthikeel,1 Andrea D Raymond,1 Venkata Atluri,1 Adriana Yndart,1 Elena M Kaftanovskaya,2 Elena Batrakova,3 Marisela Agudelo,1 Madhavan Nair1 1Center for Personalized NanoMedicine, Institute of NeuroImmune Pharmacology, Department of Immunology, 2Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA; 3UNC Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA *These authors contributed equally to this work Abstract: The human immunodeficiency virus 1 (HIV-1) still remains one of the leading life-threatening diseases in the world. The introduction of highly active antiretroviral therapy has significantly reduced disease morbidity and mortality. However, most of the drugs have variable penetrance into viral reservoir sites, including gut-associated lymphoid tissue (GALT). Being the largest lymphoid organ, GALT plays a key role in early HIV infection and host–pathogen interaction. Many different treatment options have been proposed to eradicate the virus from GALT. However, it becomes difficult to deliver traditional drugs to the GALT because of its complex physiology. In this regard, we developed a polymer-based Pluronic nanocarrier containing anti-HIV drug called efavirenz (EFV) targeting Microfold cells (M-cells) in the GALT. M-cells are specialized epithelial cells that are predominantly present in the GALT. In this work, we have exploited this paracellular transport property of M-cells for targeted delivery of Pluronic nanocarrier tagged EFV, bioconjugated with anti-M-cell-specific antibodies to the GALT (nanodrug). Preliminary characterization showed that the nanodrug (EFV-F12-COOH) is of 140 nm size with 0.3 polydispersion index, and the zeta potential of the particles was -19.38±2.2 mV. Further, drug dissolution study has shown a significantly improved sustained release over free drugs. Binding potential of nanodrug with M-cell was also confirmed with fluorescence microscopy and in vitro uptake and release studies. The anti-HIV activity of the nanodrug was also significantly higher compared to that of free drug. This novel formulation was able to show sustained release of EFV and inhibit the HIV-1 infection in the GALT compared to the free drug. The present study has potential for our in vivo targeted nanodrug delivery system by combining traditional enteric-coated capsule technique via oral administration. Keywords: HIV-1, drug delivery, GALT, M-cells

Drug abuse (e.g., methamphetamine-Meth or cocaine-Coc) is one of the major risk factors for becoming infected with HIV-1, and studies show that in combination, drug abuse and HIV-1 lead to significantly greater damage to CNS. To overcome these issues, we have developed a novel nanoformulation (NF) for drug-abusing population infected with HIV-1. In this work, a novel approach was developed for the co-encapsulation of Nelfinavir (Nel) and Rimcazole (Rico) using layer-by-layer (LbL) assembled magnetic nanoformulation for the cure of neuroAIDS. Developed NF was evaluated for blood-brain barrier (BBB) transmigration, cell uptake, cytotoxicity and efficacy (p24 assay) in HIV-1 infected primary astrocyte (HA) in presence or absence of Coc and Meth. Developed magnetic nanoformulation (NF) fabricated using the LbL approach exhibited higher amounts of drug loading (Nel and Rico) with 100% release of both the therapeutic agents in a sustained manner for 8 days. NF efficacy studies indicated a dose-dependent decrease in p24 levels in HIV-1-infected HA (~55%) compared to Coc + Meth treated (~50%). The results showed that Rico significantly subdued the effect of drugs of abuse on HIV infectivity. NF successfully transmigrated (38.8 ± 6.5%) across in vitro BBB model on the application of an external magnetic field and showed >90% of cell viability with efficient cell uptake. In conclusion, our proof of concept study revealed that sustained and concurrent release of sigma σ1 antagonist and anti-HIV drug from the developed novel sustained release NF can overcome the exacerbated effects of drugs of abuse in HIV infection and may solve the issue of medication adherence in the drug-abusing HIV-1 infected population.

Interplay between lncRNAs and mRNAs is rapidly emerging as a key epigenetic mechanism in controlling various cell functions. HIV can actively infect and/or can persist latently for years by manipulating host epigenetics; however, its molecular essence remains undiscovered in entirety. Here for the first time, we delineate the influence of HIV on global lncRNAs expression in monocytic cells lines. Our analysis revealed the expression modulation of nearly 1060 such lncRNAs which are associated with differentially expressed mRNAs in active and latent infection. This suggests a greater role of lncRNAs in regulating transcriptional and post-transcriptional gene expression during HIV infection. The differentially expressed mRNAs were involved in several different biological pathways where immunological networks were most enriched. Importantly, we discovered that HIV induces expression reversal of more than 150 lncRNAs between its active and latent infection. Also, hundreds of unique lncRNAs were identified in both infection conditions. The pathology specific "gene-expression reversal" and "on-and-off" switching of lncRNAs and associated mRNAs may lead to establish the relationship between active and HIV infection.

We have observed significantly increased HIV infection in HIV infected macrophages in the presence of cocaine that could be due to the downregulation of BST2 restriction factor in these cells. In human inflammasome PCR array, among different involved in inflammasome formation, in HIV infected macrophages in the presence of cocaine, we have observed significant upregulation of NLRP3, AIM2 genes and downstream genes IL-1β and PTGS2. Whereas negative regulatory gene MEFV was upregulated, CD40LG and PYDC1 were significantly downregulated. Among various NOD like receptors, NOD2 was significantly upregulated in both HIV alone and HIV plus cocaine treated cells. In the downstream genes, chemokine (C-C motif) ligand 2 (CCL2), CCL7 and IL-6 were significantly up regulated in HIV plus cocaine treated macrophages. We have also observed significant ROS production (in HIV and/or cocaine treated cells) which is one of the indirect-activators of inflammasomes formation. Further, we have observed early apoptosis in HIV alone and HIV plus cocaine treated macrophages which may be resultant of inflammasome formation and cspase-1 activation. These results indicate that in case of HIV infected macrophages exposed to cocaine, increased ROS production and IL-1β transcription serve as an activators for the formation of NLRP3 and AIM2 mediated inflammasomes that leads to caspase 1 mediated apoptosis.

The human immunodeficiency virus (HIV) is a neurotropic virus. It induces neurotoxicity and subsequent brain pathologies in different brain cells. Addiction to recreational drugs remarkably affects the initiation of HIV infections and expedites the progression of acquired immunodeficiency syndrome (AIDS) associated neuropathogenesis. Symptoms of HIV-associated neurocognitive disorders (HAND) are noticed in many AIDS patients. At least 50 % of HIV diagnosed cases show one or other kind of neuropathological signs or symptoms during different stages of disease progression. In the same line, mild to severe neurological alterations are seen in at least 80 % autopsies of AIDS patients. Neurological illnesses weaken the connections between neurons causing significant altercations in synaptic plasticity. Synaptic plasticity alterations during HIV infection and recreational drug abuse are mediated by complex cellular phenomena involving changes in gene expression and subsequent loss of dendritic and spine morphology and physiology. New treatment strategies with ability to deliver drugs across blood-brain barrier (BBB) are being intensively investigated. In this context, magnetic nanoparticles (MNPs) based nanoformulations have shown significant potential for target specificity, drug delivery, drug release, and bioavailability of desired amount of drugs in non-invasive brain targeting. MNPs-based potential therapies to promote neuronal plasticity during HIV infection and recreational drug abuse are being developed.

Magnetite (Fe3O4) is the most commonly and extensively explored magnetic nanoparticles (MNPs) for drug-targeting and imaging in the field of biomedicine. Nevertheless, its potential application as safe and effective drug-carrier for CNS (Central Nervous System) anomalies is very limited. Previous studies have shown an entangled epidemic of opioid use and HIV infection and increased neuropathogenesis. Opiate such as morphine, heroine, etc. are used frequently as recreational drugs. Existing treatments to alleviate the action of opioid are less effective at CNS level due to impermeability of therapeutic molecules across brain barriers. Thus, development of an advanced nanomedicine based approach may pave the way for better treatment strategies. We herein report magnetic nanoformulation of a highly selective and potent morphine antagonist, CTOP (D-Pen-Cys-Tyr-DTrp-Orn-Thr-Pen-Thr-NH2), which is impenetrable to the brain. MNPs, synthesized in size range from 25 to 40 nm, were characterized by Transmission electron microscopy and assembly of MNPs-CTOP nanoformulations were confirmed by FTIR spectroscopy and fluorescent detection. Flow-cytometry analysis showed that biological efficacy of this nanoformulation in prevention of morphine induced apoptosis in peripheral blood mononuclear cells remains equivalent to that of free CTOP. Similarly, confocal microscopy reveals comparable efficacy of free and MNPs bound CTOP in protecting modulation of neuronal dendrite and spine morphology during morphine exposure and morphine-treated HIV infection. Further, typical transmigration assay showed increased translocation of MNPs across in vitro blood-brain barrier upon exposure of external magnetic force where barrier integrity remains unaltered. Thus, the developed nanoformulation could be effective in targeting brain by application of external magnetic force to treat morphine addiction in HIV patients.

MicroRNAs (miRNAs), the post-transcriptional regulators of gene expression, play key roles in modulating many cellular processes. The changes in the expression profiles of several specific miRNAs affect the interactions between miRNA and their targets in various illnesses, including addiction, HIV, cancer etc. The presence of anti-HIV-1 microRNAs (which regulate the level of infectivity of HIV-1) have been validated in the cells which are the primary targets of HIV infection. Drugs of abuse impair the intracellular innate anti-HIV mechanism(s) in monocytes, contributing to cell susceptibility to HIV infection. Emerging evidence has implicated miRNAs are differentially expressed in response to chronic morphine treatment. Activation of mu opioid receptors (MOR) by morphine is shown to down regulate the expression of anti-HIV miRNAs. In this review, we summarize the results which demonstrate that several drugs of abuse related miRNAs have roles in the mechanisms that define addiction, and how they interact with HIV.

Background: Although highly active antiretroviral therapy (HAART) has significantly reduced the morbidity and mortality in HIV patients, virus continues to reside in the central nervous system (CNS) reservoir. Hence, a complete eradication of virus remains a challenge. HIV productively infects microglia/macrophages, but astrocytes are generally restricted to HIV infection. The relative importance of the possible replication blocks in astrocytes, however, is yet to be delineated. A recently identified restriction factor, sterile alpha motif and histidine/aspartic acid domain-containing protein 1 (SAMHD1), restricts HIV infection in resting CD4(+)T cells and in monocyte-derived dendritic cells. However, SAMHD1 expression and HIV-1 restriction activity regulation in the CNS cells are unknown. Though, certain miRNAs have been implicated in HIV restriction in resting CD4(+)T cells, their role in the CNS HIV restriction and their mode of action are not established. We hypothesized that varying SAMHD1 expression would lead to restricted HIV infection and host miRNAs would regulate SAMHD1 expression in astrocytes., Results: We found increased SAMHD1 expression and decreased miRNA expression (miR-181a and miR-155) in the astrocytes compared to microglia. We report for the first time that miR-155 and miR-181a regulated the SAMHD1 expression. Overexpression of these cellular miRNAs increased viral replication in the astrocytes, through SAMHD1 modulation. Reactivation of HIV replication was accompanied by decrease in SAMHD1 expression., Conclusions: Here, we provide a proof of concept that increased SAMHD1 in human astrocytes is in part responsible for the HIV restriction, silencing of which relieves this restriction. At this time, this concept is of theoretical nature. Further experiments are needed to confirm if HIV replication can be reactivated in the CNS reservoir.

Background: HIV-associated neurocognitive disorder (HAND) is characterized by development of cognitive, behavioral and motor abnormalities, and occurs in approximately 50% of HIV infected individuals. In the United States, the prevalence of cigarette smoking ranges from 35-70% in HIV-infected individuals compared to 20% in general population. Cognitive impairment in heavy cigarette smokers has been well reported. However, the synergistic effects of nicotine and HIV infection and the underlying mechanisms in the development of HAND are unknown., Results: In this study, we explored the role of nicotine in the progression of HAND using SK-N-MC, a neuronal cell line. SK-N-MC cells were infected with HIV-1 in the presence or absence of nicotine for 7 days. We observed significant increase in HIV infectivity in SK-N-MC treated with nicotine compared to untreated HIV-infected neuronal cells. HIV and nicotine synergize to significantly dysregulate the expression of synaptic plasticity genes and spine density; with a concomitant increase of HDAC2 levels in SK-N-MC cells. In addition, inhibition of HDAC2 up-regulation with the use of vorinostat resulted in HIV latency breakdown and recovery of synaptic plasticity genes expression and spine density in nicotine/HIV alone and in co-treated SK-N-MC cells. Furthermore, increased eIF2 alpha phosphorylation, which negatively regulates eukaryotic translational process, was observed in HIV alone and in co-treatment with nicotine compared to untreated control and nicotine alone treated SK-N-MC cells., Conclusions: These results suggest that nicotine and HIV synergize to negatively regulate the synaptic plasticity gene expression and spine density and this may contribute to the increased risk of HAND in HIV infected smokers. Apart from disrupting latency, vorinostat may be a useful therapeutic to inhibit the negative regulatory effects on synaptic plasticity in HIV infected nicotine abusers.

Background: Gut damage resulting in microbial translocation (MT) is considered a major cause of immune activation (IA) in HIV infection, but data in children are limited, particularly in the absence of antiretroviral therapy., Methods: Sixty perinatally HIV-infected, antiretroviral therapy-naive children, aged 2-12 years, were evaluated for plasma levels of lipopolysaccharide, DNA sequences encoding bacterial 16 second ribosomal DNA (16S rDNA) and soluble CD14 concurrently with markers of CD4 and CD8 T-cell IA and immune exhaustion (IE), CD4 counts, and plasma viral load. At study entry, participants were classified into immune categories (ICs): IC1 (CD4% > 25), IC2 (CD4% 15-25), and IC3 (CD4% < 15). Age-matched HIV-uninfected children served as controls. Data were evaluated at study entry and at 12 months., Results: Levels of MT, IA, and IE were increased in patients as compared with controls, were highest in patients in IC3 group, and did not change over 12 months. MT products lipopolysaccharide and 16S rDNA correlated with each other and each correlated with plasma viral load, soluble CD14, and T-cell IA and IE. There was a correlation of IA with IE. CD4 counts and percentage were inversely correlated with MT products and underlying CD4 activation., Conclusions: In a natural history cohort of HIV-infected children not on therapy, MT was more pronounced in the most severely immunocompromised patients and was associated with IA. Strategies to reduce MT may help to reduce IA and prevent CD4 depletion.

Although highly active antiretroviral therapy (HAART) has resulted in remarkable decline in the morbidity and mortality in AIDS patients, controlling HIV infections still remain a global health priority. HIV access to the CNS serves as the natural viral preserve because most antiretroviral (ARV) drugs possess inadequate or zero delivery across the brain barriers. Thus, development of target-specific, effective, safe, and controllable drug-delivery approach is an important health priority for global elimination of AIDS progression. Emergence of nanotechnology in medicine has shown exciting prospect for development of novel drug delivery systems to administer the desired therapeutic levels of ARV drugs in the CNS. Neuron-resuscitating and/or antidependence agents may also be delivered in the brain through nanocarriers to countercheck the rate of neuronal degradation during HIV infection. Several nanovehicles such as liposomes, dendrimers, polymeric nanoparticles, micelles, and solid lipid nanoparticles have been intensively explored. Recently, magnetic nanoparticles and monocytes/macrophages have also been used as carrier to improve the delivery of nanoformulated ARV drugs across the blood-brain barrier. Nevertheless, more rigorous research homework has to be elucidated to sort out the shortcomings that affect the target specificity, delivery, release, and/or bioavailability of desired amount of drugs for treatment of neuroAIDS., (Copyright © 2014 John Wiley & Sons, Ltd.)

The blood-brain barrier (BBB) is considered as the primary impediment barrier for most drugs. Delivering therapeutic agents to the brain is still a big challenge to date. In our study, a dual mechanism, receptor mediation combined with external non-invasive magnetic force, was incorporated into ferrous magnet-based liposomes for BBB transmigration enhancement. The homogenous magnetic nanoparticles (MNPs), with a size of ∼10 nm, were synthesized and confirmed by TEM and XRD respectively. The classical magnetism assay showed the presence of the characteristic superparamagnetic property. These MNPs encapsulated in PEGylated fluorescent liposomes as magneto-liposomes (MLs) showed mono-dispersion, ∼130 ± 10 nm diameter, by dynamic laser scattering (DLS) using the lipid-extrusion technique. Remarkably, a magnetite encapsulation efficiency of nearly 60% was achieved. Moreover, the luminescence and hydrodynamic size of the MLs was stable for over two months at 4 ° C. Additionally, the integrity of the ML structure remained unaffected through 120 rounds of circulation mimicking human blood fluid. After biocompatibility confirmation by cytotoxicity evaluation, these fluorescent MLs were further embedded with transferrin and applied to an in vitro BBB transmigration study in the presence or absence of external magnetic force. Comparing with magnetic force- or transferrin receptor-mediated transportation alone, their synergy resulted in 50-100% increased transmigration without affecting the BBB integrity. Consequently, confocal microscopy and iron concentration in BBB-composed cells further confirmed the higher cellular uptake of ML particles due to the synergic effect. Thus, our multifunctional liposomal magnetic nanocarriers possess great potential in particle transmigration across the BBB and may have a bright future in drug delivery to the brain.

Cocaine and other drugs of abuse increase HIV-induced immunopathogenesis; and neurobiological mechanisms of cocaine addiction implicate a key role for microRNAs (miRNAs), single-stranded non-coding RNAs that regulate gene expression and defend against viruses. In fact, HIV defends against miRNAs by actively suppressing the expression of polycistronic miRNA cluster miRNA-17/92, which encodes miRNAs including miR-20a. IFN-g production by natural killer cells is regulated by miR-155 and this miRNA is also critical to dendritic cell (DC) maturation. However, the impact of cocaine on miR-155 expression and subsequent HIV replication is unknown. We examined the impact of cocaine on two miRNAs, miR-20a and miR-155, which are integral to HIV replication, and immune activation. Using miRNA isolation and analysis, RNA interference, quantitative real time PCR, and reporter assays we explored the effects of cocaine on miR-155 and miR-20 in the context of HIV infection. Here we demonstrate using monocyte-derived dendritic cells (MDCCs) that cocaine significantly inhibited miR-155 and miR-20a expression in a dose dependent manner. Cocaine and HIV synergized to lower miR-155 and miR-20a in MDDCs by 90%. Cocaine treatment elevated LTR-mediated transcription and PU.1 levels in MDCCs. But in context of HIV infection, PU.1 was reduced in MDDCs regardless of cocaine presence. Cocaine increased DC-SIGN and and decreased CD83 expression in MDDC, respectively. Overall, we show that cocaine inhibited miR-155 and prevented maturation of MDDCs; potentially, resulting in increased susceptibility to HIV-1. Our findings could lead to the development of novel miRNA-based therapeutic strategies targeting HIV infected cocaine abusers.

Understanding the defects in innate immunity associated with perinatal HIV infection is a prerequisite for effective antiretroviral treatment. We therefore compared the innate immune response [dendritic cell (DC) phenotype and function] in peripheral blood by flow cytometry at baseline and 12 months in HIV-infected children to determine the defect associated with perinatal HIV infection. As compared with controls, patients had decreased numbers of total DCs including plasmacytoid (p)DCs and myeloid (m)DCs and impaired function based on induction of maturation markers (CD83, CD80, CCR7) and cytokines tumor necrosis factor-α and interferon-α (exclusive to pDC) upon stimulation with the TLR7/8 agonist Resiquimod. These abnormalities were evident in all three CD4 immune categories and persisted over 12 months; pDC function worsened in HIV+ children without treatment and improved slightly in those on highly active antiretroviral therapy (HAART). In conclusion, a majority of perinatally HIV-infected older children without HAART remain clinically stable in the short term, but have demonstrable immunologic abnormalities indicative of defects in the innate immune system. Children initiated on HAART showed improvement in CD4 counts but did not show improvement in DC function over the short term., (© 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.)

Advances in the drug development against HIV-1 have lead to the identification of new compounds which could be used to target cellular entry and nuclear integration of virus in addition to drugs that commonly target reverse transcriptase and protease. These additional targets have added a new dimension to fight against HIV. Cellular entry of HIV is a multistep procedure involving a range of cellular and molecular interactions between virus envelope protein and receptors expressed on the surface of the target cells, thus providing many opportunities to block infection. Some of these entry inhibitors are currently being used in the clinic and more compounds are under various stages of development. Integration of the HIV-1 DNA is required and essential to maintain the viral DNA in the infected cell. The design and discovery of integrase inhibitors were first focused at targeting the catalytic site of integrase that selectively acting on strand transfer and thus inhibits integration of virus DNA with host cell genome. Thus, entry and integrase inhibitors present a real added value in combined treatment against HIV infection. This review discusses the recent development in the discovery of inhibitors of HIV entry and integration along with some of recent patents in the field.

Parenteral use of drugs; such as opiates exert immunomodulatory effects and serve as a cofactor in the progression of HIV-1 infection, thereby potentiating HIV related neurotoxicity ultimately leading to progression of NeuroAIDS. Morphine exposure is known to induce apoptosis, down regulate cAMP response element-binding (CREB) expression and decrease in dendritic branching and spine density in cultured cells. Use of neuroprotective agent; brain derived neurotropic factor (BDNF), which protects neurons against these effects, could be of therapeutic benefit in the treatment of opiate addiction. Previous studies have shown that BDNF was not transported through the blood brain barrier (BBB) in-vivo.; and hence it is not effective in-vivo. Therefore development of a drug delivery system that can cross BBB may have significant therapeutic advantage. In the present study, we hypothesized that magnetically guided nanocarrier may provide a viable approach for targeting BDNF across the BBB. We developed a magnetic nanoparticle (MNP) based carrier bound to BDNF and evaluated its efficacy and ability to transmigrate across the BBB using an in-vitro BBB model. The end point determinations of BDNF that crossed BBB were apoptosis, CREB expression and dendritic spine density measurement. We found that transmigrated BDNF was effective in suppressing the morphine induced apoptosis, inducing CREB expression and restoring the spine density. Our results suggest that the developed nanocarrier will provide a potential therapeutic approach to treat opiate addiction, protect neurotoxicity and synaptic density degeneration.

Background: Several studies have reported adverse immunological effects of silicone due to their ability to induce proinflammatory molecules, such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). In recent years, use of nanoparticles has been under fast development for therapeutic drug targeting, diagnostic imaging, and immune response in various fields of nanomedicine. The authors hypothesize that immune responses induced by in vivo use of silicone materials can be reduced or eliminated by the use of nanosilicone., Methods: Peripheral blood mononuclear cells obtained from naïve normal subjects were cultured with different concentrations of silicone nanoparticles and microparticles for 24 hours. The culture supernatants were quantitated for TNF-α, IL-6, and interferon-γ (IFN-γ) secretion by enzyme-linked immunosorbent assay. The pellets were used for specific IL-6, TNF-α, and IFN-γ gene expression by real-time polymerase chain reaction, respectively. Cytotoxicity was evaluated by XTT viability assay. Results were compared between silicone nanoparticles and microparticles and untreated controls., Results: Silicone nanoparticles up to 100 μg/ml did not induce any detectable levels of specific TNF-α, IFN-γ, and IL-6 gene expression and protein production and the results were comparable to those for untreated controls. Silicone microparticles at 100 μg/ml, however, significantly induced the production and gene expression of TNF-α, IL-6, and IFN-γ by peripheral blood mononuclear cells. XTT viability assay showed that silicone nanoparticles or microparticles, even at the highest concentration used, were not cytotoxic to cells., Conclusions: The results suggest that silicone nanoparticles can be engineered to avoid immune recognition and subsequent silicone microparticle-related adverse effects and thus may be of therapeutic significance in the cosmetic industry, plastic surgery, and aesthetic medicine.

Background: Gut microbial translocation (MT) is considered a major cause of immune activation (IA) and failure of immune reconstitution in HIV infection. This study investigated the relationship of virus replication, IA, CD4 counts and MT in HIV-infected children., Methods: Lipopolysaccharide, bacterial 16S ribosomal DNA (16SrDNA) and soluble CD14 (sCD14) levels were determined in prospectively collected, stored plasma samples from the Pediatric AIDS Clinical Trials Group Protocol P338, a 48-week study initiated in 1997 to compare efficacy of dual nucleosides with a ritonavir-containing regimen. Results of MT were correlated with study data for T cell IA, plasma viral load and CD4 counts in 85 HIV-infected children (ages 2-17 years) designated as virologic responders or virologic failures (VF) at week 44 based on a cutoff of 400 HIV RNA copies/mL., Results: Levels of plasma lipopolysaccharide, 16SrDNA and sCD14 were increased in comparison with HIV-uninfected controls and did not decrease at week 44 even in virologic responders. T cell IA was correlated with viral load and sCD14 at entry and with 16SrDNA and sCD14 at week 44 in total patients and in the VF group. Changes in 16SrDNA correlated with changes in IA and negatively with changes in CD4 counts. 16SrDNA was correlated with sCD14 but not with lipopolysaccharide., Conclusions: MT persists after 44 weeks of antiretroviral therapy in VS and VF patients. In VF, 16SrDNA exhibited relationships to monocyte and T cell IA and CD4 counts but not with viral load, suggesting a dominant role for MT in disease pathogenesis in HIV-infected children.

HIV epidemic continues to be a severe public health problem and concern within USA and across the globe with about 33 million people infected with HIV. The frequency of drug abuse among HIV infected patients is rapidly increasing and is another major issue since injection drug users are at a greater risk of developing HIV associated neurocognitive dysfunctions compared to non-drug users infected with HIV. Brain is a major target for many of the recreational drugs and HIV. Evidences suggest that opiate drug abuse is a risk factor in HIV infection, neural dysfunction and progression to AIDS. The information available on the role of morphine as a cofactor in the neuropathogenesis of HIV is scanty. This review summarizes the results that help in understanding the role of morphine use in HIV infection and neural dysfunction. Studies show that morphine enhances HIV-1 infection by suppressing IL-8, downregulating chemokines with reciprocal upregulation of HIV coreceptors. Morphine also activates MAPK signaling and downregulates cAMP response element-binding protein (CREB). Better understanding on the role of morphine in HIV infection and mechanisms through which morphine mediates its effects may help in devising novel therapeutic strategies against HIV-1 infection in opiate using HIV-infected population.

MicroRNAs (miRNAs) are 20-22 nucleotide length noncoding RNA molecules that represent key regulators of many normal cellular functions. miRNAs undergo two processing steps which transform a long primary transcript into the mature miRNA. Available literatures demonstrate the association between alterations in the expression of miRNAs and the progression of numerous human disorders. Even though significant advances have been made, many fundamental questions about their expression and function still remain unanswered. Identifying factors that block the negative action of drugs of abuse on the miRNAs could help in identifying new therapeutic strategies. In this review, we briefly discuss the importance of miRNAs on HIV, strategies used by virus to avoid the cells' antiviral miRNA defenses, and how HIV might control and regulate host cell genes by encoding viral miRNAs.

Mechanisms underlying failure of novel 2009 H1N1 influenza vaccine-induced Ab responses in HIV-infected persons are poorly understood. This study prospectively evaluated 16 HIV-infected patients on combination antiretroviral therapy and eight healthy controls (HC) who received a single 15 μg dose of nonadjuvanted novel 2009 H1N1 influenza vaccine during the 2009 H1N1 epidemic. Peripheral blood was collected at baseline (T0) and at 7 d (T1) and 28 d (T2) postvaccination for evaluation of immune responses. Prevaccination hemagglutination inhibition Ab titer was <1:20 in all except one study participant. At T2, all HC and 8 out of 16 patients (50%) developed a vaccine-induced Ab titer of ≥ 1:40. Vaccine responder (R) and vaccine nonresponder patients were comparable at T0 in age, CD4 counts, virus load, and B cell immunophenotypic characteristics. At T2, HC and R patients developed an expansion of phenotypic and functional memory B cells and ex vivo H1N1-stimulated IgG Ab-secreting cells in an ELISPOT assay. The memory B cell response was preceded by a significant expansion of plasmablasts and spontaneous H1N1-specific Ab-secreting cells at T1. At T2, HC and R patients also exhibited significant increases in serum IL-21 levels and in the frequency and mean fluorescence intensity of IL-21R-expressing B cells, which correlated with serum H1N1 Ab titers. Vaccine nonresponder patients failed to develop the above-described vaccine-induced immunologic responses. The novel association of novel 2009 H1N1 vaccine-induced Ab responses with IL-21/IL-21R upregulation and with development of memory B cells and plasmablasts has implications for future research in vaccine design.

Functional immunologic assays using cryopreserved peripheral blood mononuclear cells (PBMC) are influenced by blood processing, storage and shipment. The objective of this study was to compare the viability, recovery and ELISPOT results of PBMC stored and shipped in liquid nitrogen (LN/LN) or stored in LN and shipped on dry ice (LN/DI) or stored at -70°C for 3 to 12 weeks and shipped on DI (70/DI 3 to 12); and to assess the effect of donor HIV infection status on the interaction between storage/shipment and the outcome measures. PBMC from 12 HIV-infected and 12 uninfected donors showed that LN/LN conferred higher viability and recovery than LN/DI or 70/DI 3, 6, 9 or 12. LN/DI PBMC had higher viability than any 70/DI PBMC. The PBMC viability and recovery linearly decreased with the duration of storage at -70°C from 3 to 12 weeks. This effect was more pronounced in samples from HIV-infected than uninfected donors. Results of ELISPOT assays using CMV pp65, CEF and Candida albicans antigens were qualitatively and quantitatively similar across LN/LN, LN/DI and 70/DI 3. However, ELISPOT values significantly decreased with the duration of storage at -70°C both in HIV-infected and uninfected donors. ELISPOT results also decreased with PBMC viability <70%., (Copyright © 2010 Elsevier B.V. All rights reserved.)