In vitro downregulation of matrix metalloproteinase-9 in rat glial cells by CCR5 antagonist maraviroc: therapeutic implication for HIV brain infection

The CCR5 antagonist maraviroc exerts limited neuroprotection without improving neurofunctional outcome in experimental pneumococcal meningitis

One-third of pneumococcal meningitis (PM) survivors suffer from neurological sequelae including learning disabilities and hearing loss due to excessive neuroinflammation. There is a lack of efficacious compounds for adjuvant therapy to control this long-term consequence of PM. One hallmark is the recruitment of leukocytes to the brain to combat the bacterial spread. However, this process induces excessive inflammation, causing neuronal injury. Maraviroc (MVC)—a CCR5 antagonist—was demonstrated to inhibit leukocyte recruitment and attenuate neuroinflammation in several inflammatory diseases. Here, we show that in vitro, MVC decreased nitric oxide production in astroglial cells upon pneumococcal stimulation. In vivo, infant Wistar rats were infected with 1 × 10⁴ CFU/ml S. pneumoniae and randomized for treatment with ceftriaxone plus MVC (100 mg/kg) or ceftriaxone monotherapy. During the acute phase, neuroinflammation in the CSF was measured and histopathological analyses were performed to determine neuronal injury. Long-term neurofunctional outcome (learning/memory and hearing capacity) after PM was assessed. MVC treatment reduced hippocampal cell apoptosis but did not affect CSF neuroinflammation and the neurofunctional outcome after PM. We conclude that MVC treatment only exerted limited effect on the pathophysiology of PM and is, therefore, not sufficiently beneficial in this experimental paradigm of PM.

Maraviroc, an inhibitor of chemokine receptor type 5, alleviates neuroinflammatory response after cerebral Ischemia/reperfusion injury via regulating MAPK/NF-κB signaling

Neuroinflammation is a key factor that contributes to the secondary damage after cerebral ischemia/reperfusion (CI/R) injury. Chemokine receptor type 5 (CCR5) has shown its pro-inflammatory effects during central nervous system (CNS) diseases. However, the role of CCR5 in CI/R injury is still unclear. In this study, we administered maraviroc (MVC, APEXBIO, UK-427857), a CCR5 antagonist, to the middle cerebral artery occlusion (MCAO) mice. In vivo studies showed that MVC was successively intraperitoneally (i.p.) injected with doses (20 mg/kg body weight) for 3 days after mice MCAO. MVC showed its neuroprotective effects in alleviating neurological deficits and infarct volumes after MCAO. The level of apoptosis and inflammation were remarkably decreased by MVC treatment after CI/R injury. Subsequently, primary microglia cells were stimulated with doses of MVC (20 nM) for 12 h after oxygen-glucose deprivation/reoxygenation model (OGD/R) in vitro. MVC significantly increased the viability of primary microglia after OGD/R. The expression of pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) in microglia was down-regulated by MVC treatment. Mechanistically, MVC also inhibited the secretion of these cytokines by microglia after OGD stimulation. Furthermore, the key components of NF-κB pathway were measured in vivo and in vitro after MCAO and OGD. MVC significantly inhibited the activity of NF-κB pathway in the above pathological environments. Finally, our data indicated that MVC treatment decreased the activation of JNK signaling pathway after CI/R injury in vivo and in vitro. The JNK activator anisomycin (AN, Beyotime, SC0132) reversed the neuroprotective effects of MVC, indicating that the JNK pathway is involved in the anti-inflammatory and anti-apoptotic mechanisms of MVC in CI/R injury. Our data demonstrated that CCR5 inhibition exhibits neuroprotective effects after CI/R injury. MVC, which is widely used for HIV treatment by its anti-virus effect, is a potential drug for the treatment of ischemic stroke in the future clinical trials. MVC has been widely used in HIV treatment which showed its safety. Based on its anti-inflammatory and anti-apoptotic mechanisms, we speculate that MVC may be a potential drug for treating ischemic stroke in future clinical trials.

Luminescent PLGA Nanoparticles for Delivery of Darunavir to the Brain and Inhibition of Matrix Metalloproteinase-9, a Relevant Therapeutic Target of HIV-Associated Neurological Disorders

Human immunodeficiency virus (HIV) can independently replicate in the central nervous system (CNS) causing neurocognitive impairment even in subjects with suppressed plasma viral load. The antiretroviral drug darunavir (DRV) has been approved for therapy of HIV-infected patients, but its efficacy in the treatment of HIV-associated neurological disorders (HAND) is limited due to the low penetration through the blood–brain barrier (BBB). Therefore, innovations in DRV formulations, based on its encapsulation in optically traceable nanoparticles (NPs), may improve its transport through the BBB, providing, at the same time, optical monitoring of drug delivery within the CNS. The aim of this study was to synthesize biodegradable polymeric NPs loaded with DRV and luminescent, nontoxic carbon dots (C-Dots) and investigate their ability to permeate through an artificial BBB and to inhibit in vitro matrix metalloproteinase-9 (MMP-9) that represents a factor responsible for the development of HIV-related neurological disorders. Biodegradable poly(lactic-co-glycolic) acid (PLGA)-based nanoformulations resulted characterized by an average hydrodynamic size less than 150 nm, relevant colloidal stability in aqueous medium, satisfactory drug encapsulation efficiency, and retained emitting optical properties in the visible region of the electromagnetic spectrum. The assay on the BBB artificial model showed that a larger amount of DRV was able to cross BBB when incorporated in the PLGA NPs and to exert an enhanced inhibition of matrix metalloproteinase-9 (MMP-9) expression levels with respect to free DRV. The overall results reveal the great potential of this class of nanovectors of DRV for an efficacious treatment of HANDs.

Neuroprotective potential of isothiocyanates in an in vitro model of neuroinflammation

Isothiocyanates (ITCs), present as glucosinolate precursors in cruciferous vegetables, have shown anti-inflammatory, antioxidant and anticarcinogenic activities. Here, we compared the effects of three different ITCs on ROS production and on the expression of matrix metalloproteinase (MMP)-2 and -9, which represent important pathogenetic factors of various neurological diseases. Primary cultures of rat astrocytes were activated by LPS and simultaneously treated with different doses of Allyl isothiocyanate (AITC), 2-Phenethyl isothiocyanate (PEITC) and 2-Sulforaphane (SFN). Results showed that SFN and PEITC were able to counteract ROS production induced by H₂O₂. The zymographic analysis of cell culture supernatants evidenced that PEITC and SFN were the most effective inhibitors of MMP-9, whereas, only SFN significantly inhibited MMP-2 activity. PCR analysis showed that all the ITCs used significantly inhibited both MMP-2 and MMP-9 expression. The investigation on the mitogen-activated protein kinase (MAPK) signaling pathway demonstrated that ITCs modulate MMP transcription by inhibition of extracellular-regulated protein kinase (ERK) activity. Results of this study suggest that ITCs could be promising nutraceutical agents for the prevention and complementary treatment of neurological diseases associated with MMP involvement.

Cenicriviroc, a dual CCR2 and CCR5 antagonist leads to a reduction in plasma fibrotic biomarkers in persons living with HIV on antiretroviral therapy

Background: Chronic HIV is associated with increased inflammation and tissue fibrosis despite suppressive antiretroviral therapy (ART). Monocytes and macrophages have been implicated in the pathogenesis of fibrosis, facilitated by chemokine receptor interactions.Methods: We assessed systemic fibrotic biomarkers (transforming growth factor beta-1 [TGF-β1], thrombospondin-1 [TSP-1], C-terminal pro-peptide of collagen type I [CICP], and IL-11) in banked plasma from a previously published 24-week open-label trial of cenicriviroc (CVC), a dual CCR2/CCR5 antagonist, among persons living with HIV (PLWH) on stable ART with undetectable plasma HIV RNA (<50 copies/mL). Fibrotic markers were assessed by ELISA and Luminex. Untreated HIV-seronegative individuals (n = 6) of similar age and demographics served as a comparator group.Results: Median age of PLWH was 55 years. At baseline, PLWH had higher median TGF-β1 (2.11 vs 1.62 ng/mL, p = 0.01), TSP-1 (236.74 vs 83.29 ng/mL, p < 0.0001), and CICP (200.46 vs 111.28 ng/mL, p = 0.01), but lower IL-11 (36.00 vs 53.74 pg/mL, p = 0.01) compared to HIV-uninfected individuals. Over 24 weeks, median TGF-β1 (-0.74 ng/mL, p = 0.006), TSP-1 (-52.12 ng/mL, p < 0.0001), and CICP (-28.12 ng/mL, p < 0.0001) decreased and IL-11 (28.98 pg/mL, p < 0.0001) increased in PLWH. At week 24, TGF-β1, CICP, and IL-11 were similar between the two groups (p > 0.05), while TSP-1 remained elevated in PLWH (p = 0.009) compared to controls.Conclusions: PLWH had higher levels of the plasma fibrotic markers TGF-β1, TSP-1, and CICP. After 24 weeks of CVC, fibrotic markers generally returned to levels comparable to HIV-uninfected controls. Dual CCR2 and CCR5 blockade may ameliorate the detrimental fibrotic events that persist in treated HIV.

Maraviroc attenuates the pathogenesis of experimental autoimmune encephalitis

It has been shown that the blockade of chemokine receptor type 5 can dampen inflammatory reaction within the central nervous system (CNS). In the present study, we utilized maraviroc, a potent antagonist o CCR5, to examine whether this drug can mitigate neuroinflammation in the spinal cord of mice induced by experimental autoimmune encephalitis (EAE), considered a murine model of multiple sclerosis (MS). For this aim, mice were immunized with myelin oligodendrocyte glycoprotein 35-55 (MOG35-55), followed by pertussis toxin to induce paralysis in EAE mice. The animals intraperitoneally received various doses of maraviroc (5, 25, and 50 mg/kg body weight) when the early clinical signs of EAE appeared. The results demonstrated that the administration of maraviroc led to a marked decrease in the clinical score and improvement in behavioral motor functions. Moreover, our finding indicated that the administration of maraviroc significantly attenuates the infiltration of inflammatory cells to the spinal cord, microgliosis, astrogliosis, pro-inflammatory cytokines, and cell death in EAE mice. The flow cytometry data indicated that a decreased number of CD4+ and CD8+ T cells in the peripheral blood of mice with EAE without affecting the number of T regulatory cells (CD4 + CD25+ forkhead box protein 3+). Finally, it seems that maraviroc is well-tolerated, and targeting CCR5 could open up a new horizon in the treatment of MS.

HIV-1 Tat promotes astrocytic release of CCL2 through MMP/PAR-1 signaling

The HIV-1 protein Tat is continually released by HIV-infected cells despite effective combination antiretroviral therapies (cART). Tat promotes neurotoxicity through enhanced expression of proinflammatory molecules from resident and infiltrating immune cells. These molecules include matrix metalloproteinases (MMPs), which are pathologically elevated in HIV, and are known to drive central nervous system (CNS) injury in varied disease settings. A subset of MMPs can activate G-protein coupled protease-activated receptor 1 (PAR-1), a receptor that is highly expressed on astrocytes. Although PAR-1 expression is increased in HIV-associated neurocognitive disorder (HAND), its role in HAND pathogenesis remains understudied. Herein, we explored Tat's ability to induce expression of the PAR-1 agonists MMP-3 and MMP-13. We also investigated MMP/PAR-1-mediated release of CCL2, a chemokine that drives CNS entry of HIV infected monocytes and remains a significant correlate of cognitive dysfunction in the era of cART. Tat exposure significantly increased the expression of MMP-3 and MMP-13. These PAR-1 agonists both stimulated the release of astrocytic CCL2, and both genetic knock-out and pharmacological inhibition of PAR-1 reduced CCL2 release. Moreover, in HIV-infected post-mortem brain tissue, within-sample analyses revealed a correlation between levels of PAR-1-activating MMPs, PAR-1, and CCL2. Collectively, these findings identify MMP/PAR-1 signaling to be involved in the release of CCL2, which may underlie Tat-induced neuroinflammation.

Inhibition of MMPs and ADAM/ADAMTS

Matrix metalloproteinases (MMPs), A Disintegrin and Metalloproteinase (ADAM) and A Disintegrin and Metalloproteinase with Thrombospondin Motif (ADAMTS) are zinc-dependent endopeptidases that play a critical role in the destruction of extracellular matrix proteins and, the shedding of membrane-bound receptor molecules in various forms of arthritis and other diseases. Under normal conditions, MMP, ADAM and ADAMTS gene expression aids in the maintenance of homeostasis. However, in inflamed synovial joints characteristic of rheumatoid arthritis and osteoarthritis. MMP, ADAM and ADAMTS production is greatly increased under the influence of pro-inflammatory cytokines. Analyses based on medicinal chemistry strategies designed to directly inhibit the activity of MMPs have been largely unsuccessful when these MMP inhibitors were employed in animal models of rheumatoid arthritis and osteoarthritis. This is despite the fact that these MMP inhibitors were largely able to suppress pro-inflammatory cytokine-induced MMP production in vitro. A focus on ADAM and ADAMTS inhibitors has also been pursued. Thus, recent progress has identified the "sheddase" activity of ADAMs as a viable target and the development of GW280264X is an experimental ADAM17 inhibitor. Of note, a monoclonal antibody, GLPG1972, developed as an ADAMTS-5 inhibitor, entered a Phase I OA clinical trial. However, the failure of many of these previously developed inhibitors to move beyond the preclinical testing phase has required that novel strategies be developed that are designed to suppress both MMP, ADAM and ADAMTS production and activity.

In vitro effect of antiretroviral drugs on cultured primary astrocytes: analysis of neurotoxicity and matrix metalloproteinase inhibition

There is little information available on the possible toxic effects that antiretroviral (ARV) drugs used for the treatment of human immunodeficiency virus (HIV)-infected subjects, may have on the central nervous system (CNS) resident cells. Moreover, it remains unclear whether the efficacy of the ARV drugs may also be due to their ability to exert extravirological effects on factors responsible for the development of HIV brain injury, e.g., matrix metalloproteinases (MMPs). This study investigates the toxicity of three different ARV drugs and on their ability to modulate levels and expression of gelatinases A (MMP-2) and B (MMP-9) in astrocytes. Primary cultures of rat astrocytes were activated by exposure to lipopolysaccaride (LPS) and simultaneously treated with darunavir, maraviroc, or raltegravir, used alone or in combination. Among the tested drugs, maraviroc was the less toxic for astrocytes. At toxic concentration (TC₅₀ ), the studied drugs induced the production of reactive oxygen species (ROS), suggesting that the oxidative stress may represent a mechanism of ARV toxicity. As assessed by gelatin zymography and RT-PCR, the single antiretroviral drugs reduced levels and expression of both MMP-2 and MMP-9 through the inhibition of the signaling transduction pathway of extracellular signal-regulated kinase1/2, which is involved in the regulation of MMP-9 gene. A synergistic inhibition of MMP-2 and MMP-9 was observed with combinations of the studied ARV drugs. The present results indicate that maraviroc, darunavir, and raltegravir, through their ability to inhibit MMP-2 and MMP-9 at doses non-toxic for astrocytes, might have a great potential for the management of HIV-associated neurological complications.

CCR5 deficiency accelerates lipopolysaccharide-induced astrogliosis, amyloid-beta deposit and impaired memory function

Chemokine receptors are implicated in inflammation and immune responses. Neuro-inflammation is associated with activation of astrocyte and amyloid-beta (Aβ) generations that lead to pathogenesis of Alzheimer disease (AD). Previous our study showed that deficiency of CC chemokine receptor 5 (CCR5) results in activation of astrocytes and Aβ deposit, and thus memory dysfunction through increase of CC chemokine receptor 2 (CCR2) expression. CCR5 knockout mice were used as an animal model with memory dysfunction. For the purpose LPS was injected i.p. daily (0.25 mg/kg/day). The memory dysfunctions were much higher in LPS-injected CCR5 knockout mice compared to CCR5 wild type mice as well as non-injected CCR5 knockout mice. Associated with severe memory dysfuction in LPS injected CCR5 knockout mice, LPS injection significant increase expression of inflammatory proteins, astrocyte activation, expressions of β-secretase as well as Aβ deposition in the brain of CCR5 knockout mice as compared with that of CCR5 wild type mice. In CCR5 knockout mice, CCR2 expressions were high and co-localized with GFAP which was significantly elevated by LPS. Expression of monocyte chemoattractant protein-1 (MCP-1) which ligands of CCR2 also increased by LPS injection, and increment of MCP-1 expression is much higher in CCR5 knockout mice. BV-2 cells treated with CCR5 antagonist, D-ala-peptide T-amide (DAPTA) and cultured astrocytes isolated from CCR5 knockout mice treated with LPS (1 μg/ml) and CCR2 antagonist, decreased the NF-ĸB activation and Aβ level. These findings suggest that the deficiency of CCR5 enhances response of LPS, which accelerates to neuro-inflammation and memory impairment.

Resveratrol regulates neuro-inflammation and induces adaptive immunity in Alzheimer's disease

Background

Treatment of mild-moderate Alzheimer’s disease (AD) subjects (N = 119) for 52 weeks with the SIRT1 activator resveratrol (up to 1 g by mouth twice daily) attenuates progressive declines in CSF Aβ40 levels and activities of daily living (ADL) scores.

Methods

For this retrospective study, we examined banked CSF and plasma samples from a subset of AD subjects with CSF Aβ42 <600 ng/ml (biomarker-confirmed AD) at baseline (N = 19 resveratrol-treated and N = 19 placebo-treated). We utilized multiplex Xmap technology to measure markers of neurodegenerative disease and metalloproteinases (MMPs) in parallel in CSF and plasma samples.

Results

Compared to the placebo-treated group, at 52 weeks, resveratrol markedly reduced CSF MMP9 and increased macrophage-derived chemokine (MDC), interleukin (IL)-4, and fibroblast growth factor (FGF)-2. Compared to baseline, resveratrol increased plasma MMP10 and decreased IL-12P40, IL12P70, and RANTES. In this subset analysis, resveratrol treatment attenuated declines in mini-mental status examination (MMSE) scores, change in ADL (ADCS-ADL) scores, and CSF Aβ42 levels during the 52-week trial, but did not alter tau levels.

Conclusions

Collectively, these data suggest that resveratrol decreases CSF MMP9, modulates neuro-inflammation, and induces adaptive immunity. SIRT1 activation may be a viable target for treatment or prevention of neurodegenerative disorders.

Trial registration

ClinicalTrials.gov NCT01504854

Neurocognition with maraviroc compared with tenofovir in HIV

OBJECTIVE

The objective was to determine whether maraviroc (MVC) has unique neurocognitive benefits in the context of initial antiretroviral therapy (ART).

DESIGN

Randomized, double-blind, placebo-controlled, 48-week trial.

SETTING

Participants were enrolled in US AIDS Clinical Trials Group clinical trial sites.

PARTICIPANTS

Total 262 ART-naive, chemokine coreceptor 5 tropic HIV, and HIV RNA greater than 1000 copies/ml participants were randomized, 230 participants completed the study.

INTERVENTION

Participants received MVC 150 mg or tenofovir disoproxil fumarate (TDF) 300 mg on a background of ritonavir-boosted darunavir and emtricitabine.

MAIN OUTCOME MEASURE(S)

The neuropsychological battery of 15 tests done at baseline, week 24 and week 48 assessed seven domains, and were standardized into z-scores then converted into deficit scores and a global deficit score. The 48-week changes from baseline in the neuropsychological scores and the global deficit score were compared by Wilcoxon or Kruskal-Wallis test between arms, and among baseline impairment groups [classified as normal, mild (2 deficit scores ≥1) and moderate (2 deficit scores ≥2)]. It was hypothesized that the MVC arm would have improved neuropsychological performance over TDF.

RESULTS

In this double-blind, randomized, placebo-controlled trial, there were no differences in neuropsychological performance between MVC and TDF. Those with moderate neuropsychological impairment at baseline experienced greater ART-mediated neuropsychological improvement than those with mild or no neuropsychological impairment.

CONCLUSION

Improvement in neurocognitive functioning was greater with more baseline impairment but was comparable with MVC or TDF.

MMP-9 in translation: from molecule to brain physiology, pathology, and therapy

Matrix metalloproteinase-9 (MMP-9) is a member of the metzincin family of mostly extracellularly operating proteases. Despite the fact that all of these enzymes might be target promiscuous, with largely overlapping catalogs of potential substrates, MMP-9 has recently emerged as a major and apparently unique player in brain physiology and pathology. The specificity of MMP-9 may arise from its very local and time-restricted actions, even when released in the brain from cells of various types, including neurons, glia, and leukocytes. In fact, the quantity of MMP-9 is very low in the naive brain, but it is markedly activated at the levels of enzymatic activity, protein abundance, and gene expression following various physiological stimuli and pathological insults. Neuronal MMP-9 participates in synaptic plasticity by controlling the shape of dendritic spines and function of excitatory synapses, thus playing a pivotal role in learning, memory, and cortical plasticity. When improperly unleashed, MMP-9 contributes to a large variety of brain disorders, including epilepsy, schizophrenia, autism spectrum disorder, brain injury, stroke, neurodegeneration, pain, brain tumors, etc. The foremost mechanism of action of MMP-9 in brain disorders appears to be its involvement in immune/inflammation responses that are related to the enzyme's ability to process and activate various cytokines and chemokines, as well as its contribution to blood-brain barrier disruption, facilitating the extravasation of leukocytes into brain parenchyma. However, another emerging possibility (i.e., the control of MMP-9 over synaptic plasticity) should not be neglected. The translational potential of MMP-9 has already been recognized in both the diagnosis and treatment domains. The most striking translational aspect may be the discovery of MMP-9 up-regulation in a mouse model of Fragile X syndrome, quickly followed by human studies and promising clinical trials that have sought to inhibit MMP-9. With regard to diagnosis, suggestions have been made to use MMP-9 alone or combined with tissue inhibitor of matrix metalloproteinase-1 or brain-derived neurotrophic factor as disease biomarkers. MMP-9, through cleavage of specific target proteins, plays a major role in synaptic plasticity and neuroinflammation, and by those virtues contributes to brain physiology and a host of neurological and psychiatric disorders. This article is part of the 60th Anniversary special issue.

Inhibitory Effect of Aqueous Extracts from Marine Sponges on the Activity and Expression of Gelatinases A (MMP-2) and B (MMP-9) in Rat Astrocyte Cultures

The aim of this study was to evaluate whether water soluble compounds present in aqueous extracts from seven Mediterranean demosponges exert biological activity towards matrix metalloproteinases (MMPs), which represent important pathogenic factors of human diseases. Aqueous extracts were tested on LPS-activated cultured rat astrocytes, and levels and expression of MMP-2 and MMP-9 were assessed by zymography and RT-PCR, respectively. Our results demonstrated that the studied extracts contain water soluble compounds able to inhibit MMP-2 and MMP-9 activity and expression. We also compared the anti-MMP activities present in aqueous extracts from wild and reared specimens of Tethya aurantium and T. citrina. The results obtained revealed that the reared sponges maintain the production of bioactive compounds with inhibitory effect on MMP-2 and MMP-9 for all the duration of the rearing period. Taken together, our results indicate that the aqueous extracts from the selected Mediterranean demosponges possess a variety of water-soluble bioactive compounds, which are able to inhibit MMPs at different levels. The presence of biological activity in aqueous extracts from reared specimens of T. aurantium and T. citrina strongly encourage sponge aquaculture as a valid option to supply sponge biomass for drug development on a large scale.

Exposure of human astrocytes to leukotriene C4 promotes a CX3CL1/fractalkine-mediated transmigration of HIV-1-infected CD4⁺ T cells across an in vitro blood-brain barrier model

Eicosanoids, including cysteinylleukotrienes (cysLTs), are found in the central nervous system (CNS) of individuals infected with HIV-1. Few studies have addressed the contribution of cysLTs in HIV-1-associated CNS disorders. We demonstrate that conditioned medium from human astrocytes treated with leukotriene C4 (LTC4) increases the transmigration of HIV-1-infected CD4(+) T cells across an in vitro blood-brain barrier (BBB) model using cultured brain endothelial cells. Additional studies indicate that the higher cell migration is linked with secretion by astrocytes of CX3CL1/fractalkine, a chemokine that has chemoattractant activity for CD4(+) T cells. Moreover, we report that the enhanced cell migration across BBB leads to a more important CD4(+) T cell-mediated HIV-1 transfer toward macrophages. Altogether data presented in the present study reveal the important role that LTC4, a metabolite of arachidonic acid, may play in the HIV-1-induced neuroinvasion, neuropathogenesis and disease progression.

HIV-1 induces cytoskeletal alterations and Rac1 activation during monocyte-blood-brain barrier interactions: modulatory role of CCR5

Background

Most HIV strains that enter the brain are macrophage-tropic and use the CCR5 receptor to bind and infect target cells. Because the cytoskeleton is a network of protein filaments involved in cellular movement and migration, we investigated whether CCR5 and the cytoskeleton are involved in endothelial-mononuclear phagocytes interactions, adhesion, and HIV-1 infection.

Results

Using a cytoskeleton phospho-antibody microarray, we showed that after co-culture with human brain microvascular endothelial cells (HBMEC), HIV-1 infected monocytes increased expression and activation of cytoskeleton-associated proteins, including Rac1/cdc42 and cortactin, compared to non-infected monocytes co-cultured with HBMEC. Analysis of brain tissues from HIV-1-infected patients validated these findings, and showed transcriptional upregulation of Rac1 and cortactin, as well as increased activation of Rac1 in brain tissues of HIV-1-infected humans, compared to seronegative individuals and subjects with HIV-1-encephalitis. Confocal imaging showed that brain cells expressing phosphorylated Rac1 were mostly macrophages and blood vessels. CCR5 antagonists TAK-799 and maraviroc prevented HIV-induced upregulation and phosphorylation of cytoskeleton-associated proteins, prevented HIV-1 infection of macrophages, and diminished viral-induced adhesion of monocytes to HBMEC. Ingenuity pathway analysis suggests that during monocyte-endothelial interactions, HIV-1 alters protein expression and phosphorylation associated with integrin signaling, cellular morphology and cell movement, cellular assembly and organization, and post-translational modifications in monocytes. CCR5 antagonists prevented these HIV-1-induced alterations.

Conclusions

HIV-1 activates cytoskeletal proteins during monocyte-endothelial interactions and increase transcription and activation of Rac1 in brain tissues. In addition to preventing macrophage infection, CCR5 antagonists could diminish viral-induced alteration and phosphorylation of cytoskeletal proteins, monocyte adhesion to the brain endothelium and viral entry into the central nervous system.

Effect of maraviroc intensification on HIV-1-specific T cell immunity in recently HIV-1-infected individuals

Background

The effect of maraviroc on the maintenance and the function of HIV-1-specific T cell responses remains unknown.

Methods

Subjects recently infected with HIV-1 were randomized to receive anti-retroviral treatment with or without maraviroc intensification for 48 weeks, and were monitored up to week 60. PBMC and in vitro-expanded T cells were tested for responses to the entire HIV proteome by ELISpot analyses. Intracellular cytokine staining assays were conducted to monitor the (poly)-functionality of HIV-1-specific T cells. Analyses were performed at baseline and week 24 after treatment start, and at week 60 (3 months after maraviroc discontinuation).

Results

Maraviroc intensification was associated with a slower decay of virus-specific T cell responses over time compared to the non-intensified regimen in both direct ex-vivo as well as in in-vitro expanded cells. The effector function profiles of virus-specific CD8⁺ T cells were indistinguishable between the two arms and did not change over time between the groups.

Conclusions

Maraviroc did not negatively impact any of the measured parameters, but was rather associated with a prolonged maintenance of HIV-1-specific T cell responses. Maraviroc, in addition to its original effect as viral entry inhibitor, may provide an additional benefit on the maintenance of virus-specific T cells which may be especially important for future viral eradication strategies.

Matrix metalloproteinase levels in early HIV infection and relation to in vivo brain status

Matrix metalloproteinases (MMPs) have been implicated in human immunodeficiency virus (HIV)-associated neurological injury; however, this relationship has not been studied early in infection. Plasma levels of MMP-1, MMP-2, MMP-7, MMP-9, and MMP-10 measured using Luminex technology (Austin, TX, USA) were compared in 52 HIV and 21 seronegative participants of the Chicago Early HIV Infection study. MMP levels were also examined in HIV subgroups defined by antibody reactivity, viremia, and antiretroviral status, as well as in available cerebrospinal fluid (CSF) samples (n = 9). MMPs were evaluated for patterns of relationship to cognitive function and to quantitative magnetic resonance measurements of the brain derived in vivo. Plasma MMP-2 levels were significantly reduced in early HIV infection and correlated with altered white matter integrity and atrophic brain changes. MMP-9 levels were higher in the treated subgroup than in the naïve HIV subgroup. Only MMP-2 and MMP-9 were detected in the CSF; CSF MMP-2 correlated with white matter integrity and with volumetric changes in basal ganglia. Relationships with cognitive function were also identified. MMP-2 levels in plasma and in CSF correspond to early changes in brain structure and function. These findings establish a link between MMPs and neurological status previously unidentified in early HIV infection.