Blocking CCR5 activity by maraviroc augmentation in post-stroke depression: a proof-of-concept clinical trial.

BACKGROUND: Post-stroke depression (PSD) is a significant impediment to successful rehabilitation and recovery after a stroke. Current therapeutic options are limited, leaving an unmet demand for specific and effective therapeutic options. Our objective was to investigate the safety of Maraviroc, a CCR5 antagonist, as a possible mechanism-based add-on therapeutic option for PSD in an open-label proof-of-concept clinical trial. METHODS: We conducted a 10-week clinical trial in which ten patients with subcortical and cortical stroke, suffering from PSD. were administered a daily oral dose of 300 mg Maraviroc. Participants were then monitored for an additional eight weeks. The primary outcome measure was serious treatment-emergent adverse events (TEAEs) and TEAEs leading to discontinuation. The secondary outcome measure was a change in the Montgomery-Asberg Depression Rating Scale (MADRS). RESULTS: Maraviroc was well tolerated, with no reports of serious adverse events or discontinuations due to intolerance. The MADRS scores substantially reduced from baseline to week 10 (mean change: -16.4 ± 9.3; p < 0.001). By the conclusion of the treatment phase, a favorable response was observed in five patients, with four achieving remission. The time to response was relatively short, approximately three weeks. After the cessation of treatment, MADRS scores increased at week 18 by 6.1 ± 9.6 points (p = 0.014). CONCLUSIONS: Our proof-of-concept study suggests that a daily dosage of 300 mg of Maraviroc may represent a well-tolerated and potentially effective pharmacological approach to treating PSD. Further comprehensive placebo-controlled studies are needed to assess the impact of Maraviroc augmentation on PSD. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05932550, Retrospectively registered: 28/06/2023.

A novel small-molecular CCR5 antagonist promotes neural repair after stroke.

Chemokine receptor 5 (CCR5) is one of the main co-receptors of HIV-1, and has been found to be a potential therapeutic target for stroke. Maraviroc is a classic CCR5 antagonist, which is undergoing clinical trials against stroke. As maraviroc shows poor blood-brain barrier (BBB) permeability, it is of interest to find novel CCR5 antagonists suitable for neurological medication. In this study we characterized the therapeutic potential of a novel CCR5 antagonist A14 in treating ischemic stroke mice. A14 was discovered in screening millions compounds in the Chemdiv library based on the molecular docking diagram of CCR5 and maraviroc. We found that A14 dose-dependently inhibited the CCR5 activity with an IC50 value of 4.29 µM. Pharmacodynamic studies showed that A14 treatment exerted protective effects against neuronal ischemic injury both in vitro and vivo. In a SH-SY5Y cell line overexpressing CCR5, A14 (0.1, 1 µM) significantly alleviated OGD/R-induced cell injury. We found that the expression of CCR5 and its ligand CKLF1 was significantly upregulated during both acute and recovery period in focal cortical stroke mice; oral administration of A14 (20 mg·kg-1·d-1, for 1 week) produced sustained protective effect against motor impairment. A14 treatment had earlier onset time, lower onset dosage and much better BBB permeability compared to maraviroc. MRI analysis also showed that A14 treatment significantly reduced the infarction volume after 1 week of treatment. We further revealed that A14 treatment blocked the protein-protein interaction between CCR5 and CKLF1, increasing the activity of CREB signaling pathway in neurons, thereby improving axonal sprouting and synaptic density after stroke. In addition, A14 treatment remarkably inhibited the reactive proliferation of glial cells after stroke and reduced the infiltration of peripheral immune cells. These results demonstrate that A14 is a promising novel CCR5 antagonist for promoting neuronal repair after ischemic stroke. A14 blocked the protein-protein interaction between CKLF1 and CCR5 after stroke by binding with CCR5 stably, improved the infarct area and promoted motor recovery through reversing the CREB/pCREB signaling which was inhibited by activated CCR5 Gαi pathway, and benefited to the dendritic spines and axons sprouting.

CC chemokine receptor 5 antagonist alleviates inflammation by regulating IFN-γ/IL-10 and STAT4/Smad3 signaling in a mouse model of autoimmune encephalomyelitis.

Multiple sclerosis (MS) is an immunopathological disease that causes demyelination and recurrent episodes of T cell-mediated immune attack in the central nervous system. Experimental autoimmune encephalomyelitis (EAE) is a well-established mouse model of MS. The roles of T cells in MS/EAE have been well investigated, but little is known about the role of CCR5+ cells. In the present study, we investigated whether treatment with DAPTA, a selective CCR5 antagonist, could modulate the progression of EAE in the SJL/J mice. EAE mice were treated with DAPTA (0.01 mg/kg) intraperitoneally daily from day 14 to day 42, and the clinical scores were evaluated. We further investigated the effects of DAPTA on IFN-γ-, TGF-ß-, IL-10-, IL-17A-, IL-22-, T-bet, STAT4-, RORγT-, AhR-, Smad3-, and Foxp3-expressing CCR5+ spleen cells using flow cytometry analysis. We further explored the effects of DAPTA on mRNA/protein expression of IFN-γ, IL-10, IL-17A, IL-22, TGF-ß, T-bet, STAT4, RORγT, AhR, Foxp3, and NF-H in the brain tissue. The severity of clinical scores decreased in DAPTA-treated EAE mice as compared to that in the EAE control mice. Moreover, the percentage of CCR5+IFN-γ+, CCR5+T-bet+, CCR5+STAT4+, CCR5+IL-17A+, CCR5+RORγt+, CCR5+IL-22+, and CCR5+AhR+ cells decreased while CCR5+TGF-ß+, CCR5+IL-10+, CCR5+Smad3+, and CCR5+Foxp3+ increased in DAPTA-treated EAE mice. Furthermore, DAPTA treatment significantly mitigated the EAE-induced expression of T-bet, STAT4, IL-17A, RORγT, IL-22, and AhR but upregulated Foxp3, IL-10, and NF-H expression in the brain tissue. Taken together, our data demonstrated that DAPTA could ameliorate EAE progression through the downregulation of the inflammation-related cytokines and transcription factors signaling, which may be useful for the clinical therapy of MS.

Chemokine Receptor 5 Antagonism Causes Reduction in Joint Inflammation in a Collagen-Induced Arthritis Mouse Model.

Rheumatoid arthritis (RA) is a chronic inflammatory disease mainly affecting the synovial joints. A highly potent antagonist of C-C chemokine receptor 5 (CCR5), maraviroc (MVC), plays an essential role in treating several infectious diseases but has not yet been evaluated for its potential effects on RA development. This study focused on evaluating the therapeutic potential of MVC on collagen-induced arthritis (CIA) in DBA/1J mice. Following CIA induction, animals were treated intraperitoneally with MVC (50 mg/kg) daily from day 21 until day 35 and evaluated for clinical score and histopathological changes in arthritic inflammation. We further investigated the effect of MVC on Th9 (IL-9, IRF-4, and GATA3) and Th17 (IL-21R, IL-17A, and RORγT) cells, TNF-α, and RANTES in CD8+ T cells in the spleen using flow cytometry. We also assessed the effect of MVC on mRNA and protein levels of IL-9, IL-17A, RORγT, and GATA3 in knee tissues using RT-PCR and western blot analysis. MVC treatment in CIA mice attenuated the clinical and histological severity of inflammatory arthritis, and it substantially decreased IL-9, IRF4, IL-21R, IL-17A, RORγT, TNF-α, and RANTES production but increased GATA3 production in CD8+ T cells. We further observed that MVC treatment decreased IL-9, IL-17A, and RORγt mRNA and protein levels and increased those of GATA3. This study elucidates the capacity of MVC to ameliorate the clinical and histological signs of CIA by reducing pro-inflammatory responses, suggesting that MVC may have novel therapeutic uses in the treatment of RA.

Addition of maraviroc to antiretroviral therapy decreased interferon-γ mRNA in the CD4+ T cells of patients with suboptimal CD4+ T-cell recovery.

The CCR5 antagonist, maraviroc (MVC), is associated with an enhanced CD4+ T-cell response independent of virological suppression; however, its mechanism of action has not been elucidated. In this study, we confirmed the effect of MVC on CD4+ T-cell count recovery in immunological non-responders, and compared the conventional combination antiretroviral therapy (cART) with MVC-intensified cART. We also investigated the effect of MVC on interferon-γ (IFN-γ) production in CD4+ T cells in vitro and in vivo, and evaluated the relationship between the mRNA level of IFN-γ and the degree of CD4+ T-cell count recovery. In vitro analysis indicated that MVC significantly decreased mRNA levels of IFN-γ in HIV-Tat stimulated CD4+ T cells from healthy donor peripheral blood mononuclear cells. Of the 18 HIV-infected patients treated with MVC-intensified cART, 12 had a significantly increased CD4+ T-cell count after 24 weeks of additional treatment with MVC. In patients exhibiting a response in CD4+ T-cell counts, mRNA levels of IFN-γ in CD4+ T cells were lower than those in patients showing a non-response at baseline and at week 24, while mRNA levels of IFN-γ decreased in both groups at 24 weeks. In conclusion, MVC decreased the mRNA level of IFN-γ in CD4+ T cells in vitro and in vivo, especially in patients whose CD4+ T-cell count increased significantly. We also found that the lower baseline IFN-γ mRNA level and the larger decreased rate of IFN-γ mRNA in CD4+ T cells were associated with a good response to MVC regarding CD4+ T-cell recovery.

Design, synthesis, and biological evaluation of novel 2-methylpiperazine derivatives as potent CCR5 antagonists.

Three series of novel 2-methylpiperazine derivatives were designed and synthesized using a fragment-assembly strategy. Among them, six compounds (13, 16, 18, 22, 33, and 36) showed potent activity against CCR5 comparable to that of the positive control, maraviroc, in calcium mobilization assay. Moreover, some compounds were selected and further tested for their antiviral activity in HIV-1 single cycle assay. As a result, four compounds (13, 16, 33, and 36) showed antiviral activity at the nanomolar level. Additionally, the potent four compounds showed no cytotoxicity at a concentration of 10µM.

Corrigendum: Case Series: Maraviroc and pravastatin as a therapeutic option to treat long COVID/Post-acute sequalae of COVID (PASC).

[This corrects the article DOI: 10.3389/fmed.2023.1122529.].

In ovarian cancer maraviroc potentiates the antitumoral activity and further inhibits the formation of a tumor-promoting microenvironment by trabectedin.

Ovarian cancer (OC) is the fifth most frequent cause of cancer-related death in women. Chemotherapy agent trabectedin, affecting cancer cells and tumor microenvironment, has been approved for the treatment of relapsed platinum-sensitive OC patients. CCR5-antagonist maraviroc inhibits tumor growth, metastasis, and enhances the antitumoral activity of DNA-damaging drugs. Here, we found that OC cells expressed CCR5 receptor but did not secret CCR5-ligands. Maraviroc treatment did not affect OC cell viability, but strongly potentiated the antiproliferative activity, apoptosis induction, cell cycle blockage, DNA damage, and ROS formation by trabectedin. In A2780cis cisplatin-resistant cells, the cross-resistance to trabectedin was overcame by the combination with maraviroc. Maraviroc enhanced trabectedin cytotoxicity in OC 3Dimensional spheroids and THP-1-monocytes. Both maraviroc and trabectedin interact with drug efflux pump MDR1/P-gp, overexpressed in recurrent OC patients. Maraviroc increased trabectedin intracellular accumulation and the MDR1-inhibitor verapamil, like maraviroc, increased trabectedin cytotoxicity. In OC tumor xenografts the combination with maraviroc further reduced tumor growth, angiogenesis, and monocyte infiltration by trabectedin. In conclusion, this study offers a preclinical rationale for the use of maraviroc as new option to improve trabectedin activity in relapsed chemoresistant OC patients.

Inhibition of intrahepatic monocyte recruitment by Cenicriviroc and extracellular matrix degradation by MMP1 synergistically attenuate liver inflammation and fibrogenesis in vivo.

The chemokine (CCL)-chemokine receptor (CCR2) interaction, importantly CCL2-CCR2, involved in the intrahepatic recruitment of monocytes upon liver injury promotes liver fibrosis. CCL2-CCR2 antagonism using Cenicriviroc (CVC) showed promising results in several preclinical studies. Unfortunately, CVC failed in phase III clinical trials due to lack of efficacy to treat liver fibrosis. Lack of efficacy could be attributed to the fact that macrophages are also involved in disease resolution by secreting matrix metalloproteinases (MMPs) to degrade extracellular matrix (ECM), thereby inhibiting hepatic stellate cells (HSCs) activation. HSCs are the key pathogenic cell types in liver fibrosis that secrete excessive amounts of ECM causing liver stiffening and liver dysfunction. Knowing the detrimental role of intrahepatic monocyte recruitment, ECM, and HSCs activation during liver injury, we hypothesize that combining CVC and MMP (MMP1) could reverse liver fibrosis. We evaluated the effects of CVC, MMP1 and CVC + MMP1 in vitro and in vivo in CCl4-induced liver injury mouse model. We observed that CVC + MMP1 inhibited macrophage migration, and TGF-ß induced collagen-I expression in fibroblasts in vitro. In vivo, MMP1 + CVC significantly inhibited normalized liver weights, and improved liver function without any adverse effects. Moreover, MMP1 + CVC inhibited monocyte infiltration and liver inflammation as confirmed by F4/80 and CD11b staining, and TNFα gene expression. MMP1 + CVC also ameliorated liver fibrogenesis via inhibiting HSCs activation as assessed by collagen-I staining and collagen-I and α-SMA mRNA expression. In conclusion, we demonstrated that a combination therapeutic approach by combining CVC and MMP1 to inhibit intrahepatic monocyte recruitment and increasing collagen degradation respectively ameliorate liver inflammation and fibrosis.

Case series: Maraviroc and pravastatin as a therapeutic option to treat long COVID/Post-acute sequelae of COVID (PASC).

Post-acute sequelae of COVID (PASC), or long COVID, is a multisystem complication of SARS-CoV-2 infection that continues to debilitate millions worldwide thus highlighting the public health importance of identifying effective therapeutics to alleviate this illness. One explanation behind PASC may be attributed to the recent discovery of persistent S1 protein subunit of SARS-CoV-2 in CD16+ monocytes up to 15 months after infection. CD16+ monocytes, which express both CCR5 and fractalkine receptors (CX3CR1), play a role in vascular homeostasis and endothelial immune surveillance. We propose targeting these receptors using the CCR5 antagonist, maraviroc, along with pravastatin, a fractalkine inhibitor, could disrupt the monocytic-endothelial-platelet axis that may be central to the etiology of PASC. Using five validated clinical scales (NYHA, MRC Dyspnea, COMPASS-31, modified Rankin, and Fatigue Severity Score) to measure 18 participants' response to treatment, we observed significant clinical improvement in 6 to 12 weeks on a combination of maraviroc 300 mg per oral twice a day and pravastatin 10 mg per oral daily. Subjective neurological, autonomic, respiratory, cardiac and fatigue symptoms scores all decreased which correlated with statistically significant decreases in vascular markers sCD40L and VEGF. These findings suggest that by interrupting the monocytic-endothelial-platelet axis, maraviroc and pravastatin may restore the immune dysregulation observed in PASC and could be potential therapeutic options. This sets the framework for a future double-blinded, placebo-controlled randomized trial to further investigate the drug efficacy of maraviroc and pravastatin in treating PASC.

DAPTA, a C-C Chemokine Receptor 5 (CCR5), Leads to the Downregulation of Notch/NF-κB Signaling and Proinflammatory Mediators in CD40+ Cells in Experimental Autoimmune Encephalomyelitis Model in SJL/J Mice.

Multiple sclerosis (MS) is an autoimmune inflammatory disease of the central nervous system characterized by motor deficits, cognitive impairment, fatigue, pain, and sensory and visual dysfunction. CD40, highly expressed in B cells, plays a significant role in MS pathogenesis. The experimental autoimmune encephalomyelitis (EAE) mouse model of MS has been well established, as well as its relevance in MS patients. This study aimed to evaluate the therapeutic potential of DAPTA, a selective C-C chemokine receptor 5 (CCR5) antagonist in the murine model of MS, and to expand the knowledge of its mechanism of action. Following the induction of EAE, DAPTA was administrated (0.01 mg/kg, i.p.) daily from day 14 to day 42. We investigated the effects of DAPTA on NF-κB p65, IκBα, Notch-1, Notch-3, GM-CSF, MCP-1, iNOS, and TNF-α in CD40+ spleen B cells using flow cytometry. Furthermore, we also analyzed the effect of DAPTA on NF-κB p65, IκBα, Notch-1, Notch-3, GM-CSF, MCP-1, iNOS, and TNF-α mRNA expression levels using qRT-PCR in brain tissue. EAE mice treated with DAPTA showed substantial reductions in NF-κB p65, Notch-1, Notch-3, GM-CSF, MCP-1, iNOS, and TNF-α but an increase in the IκBα of CD40+ B lymphocytes. Moreover, EAE mice treated with DAPTA displayed decreased NF-κB p65, Notch-1, Notch-3, GM-CSF, MCP-1, iNOS, and TNF-α and but showed increased IκBα mRNA expression levels. This study showed that DAPTA has significant neuroprotective potential in EAE via the downregulation of inflammatory mediators and NF-κB/Notch signaling. Collectively, DAPTA might have potential therapeutic targets for use in MS treatment.

Pharmacological Modulation of the MIP-1 Family and Their Receptors Reduces Neuropathic Pain Symptoms and Influences Morphine Analgesia: Evidence from a Mouse Model.

Neuropathic pain pathophysiology is not fully understood, but it was recently shown that MIP-1 family members (CCL3, CCL4, and CCL9) have strong pronociceptive properties. Our goal was to examine how pharmacological modulation of these chemokines and their receptors (CCR1 and CCR5) influence hypersensitivity after nerve injury in Albino Swiss male mice. The spinal changes in the mRNA/protein levels of the abovementioned chemokines and their receptors were measured using RT-qPCR and ELISA/Western blot techniques in a mouse model of chronic constriction injury of the sciatic nerve. Behavioral studies were performed using the von Frey and cold plate tests after pharmacological treatment with neutralizing antibodies (nAbs) against chemokines or antagonists (CCR1-J113863, CCR5-TAK-220/AZD-5672) alone and in coadministration with morphine on Day 7, when the hypersensitivity was fully developed. Our results showed enhanced protein levels of CCL3 and CCL9 1 and 7 days after nerve injury. The single intrathecal administration of CCL3 or CCL9 nAb, J113863, TAK-220, or AZD-5672 diminished neuropathic pain symptoms and enhanced morphine analgesia. These findings highlight the important roles of CCL3 and CCL9 in neuropathic pain and additionally indicate that these chemokines play essential roles in opioid analgesia. The obtained results suggest CCR1 and CCR5 as new, interesting targets in neuropathy treatment.

Maraviroc promotes recovery from traumatic brain injury in mice by suppression of neuroinflammation and activation of neurotoxic reactive astrocytes.

Neuroinflammation and the NACHT, LRR, and PYD domains-containing protein 3 inflammasome play crucial roles in secondary tissue damage following an initial insult in patients with traumatic brain injury (TBI). Maraviroc, a C-C chemokine receptor type 5 antagonist, has been viewed as a new therapeutic strategy for many neuroinflammatory diseases. We studied the effect of maraviroc on TBI-induced neuroinflammation. A moderate-TBI mouse model was subjected to a controlled cortical impact device. Maraviroc or vehicle was injected intraperitoneally 1 hour after TBI and then once per day for 3 consecutive days. Western blot, immunohistochemistry, and TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling) analyses were performed to evaluate the molecular mechanisms of maraviroc at 3 days post-TBI. Our results suggest that maraviroc administration reduced NACHT, LRR, and PYD domains-containing protein 3 inflammasome activation, modulated microglial polarization from M1 to M2, decreased neutrophil and macrophage infiltration, and inhibited the release of inflammatory factors after TBI. Moreover, maraviroc treatment decreased the activation of neurotoxic reactive astrocytes, which, in turn, exacerbated neuronal cell death. Additionally, we confirmed the neuroprotective effect of maraviroc using the modified neurological severity score, rotarod test, Morris water maze test, and lesion volume measurements. In summary, our findings indicate that maraviroc might be a desirable pharmacotherapeutic strategy for TBI, and C-C chemokine receptor type 5 might be a promising pharmacotherapeutic target to improve recovery after TBI.

Design and in silico investigation of novel Maraviroc analogues as dual inhibition of CCR-5/SARS-CoV-2 Mpro.

A sudden increase in life-threatening COVID-19 infections around the world inflicts global crisis and emotional trauma. In current study two druggable targets, namely SARS-COV-2 Mpro and CCR-5 were selected due to their significant nature in the viral life cycle and cytokine molecular storm respectively. The systematic drug repurposing strategy has been utilized to recognize inhibitory mechanism through extensive in silico investigation of novel Maraviroc analogues as promising inhibitors against SARS-CoV-2 Mpro and CCR-5. The dual inhibition specificity approach implemented in present study using molecular docking, molecular dynamics (MD), principal component analysis (PCA), free energy landscape (FEL) and MM/PBSA binding energy studies. The proposed Maraviroc analogues obtained from in silico investigation could be easily synthesized and constructive in developing significant drug against COVID-19 pandemic, with essentiality of their in vivo/in vitro evaluation to affirm the conclusions of this study. This will further fortify the concept of single drug targeting dual inhibition mechanism for treatment of COVID-19 infection and complications.

[CCR5 antagonists and HIV-1 infection: Bases and consequences of this therapeutic approach]. / Antagonistes du récepteur CCR5 et infection par le VIH-1 : bases et conséquences de cette approche thérapeutique.

CCR5 molecule is a chemokine receptor with an important role in infectious diseases; not only is it the main coreceptor for HIV-1, but it has also been involved in the immune defense against various transmissible agents. CCR5 antagonists constitute a new class of antiretrovirals. Three molecules of this class have reached phases 2B and 3 of clinical development: aplaviroc (GlaxoSmithKine), vicriviroc (Schering-Plough) and maraviroc (Pfizer). The development of aplaviroc was stopped because of some cases of drug-induced hepatitis. In ACTG 5211 and Motivate trials, adding vicriviroc (in phase 3 trials) or maraviroc (now approved for clinical use) respectively to an optimized background regimen in treatment-experienced patients has resulted in a significant virologic benefit. The place of this new therapeutic class in strategies of initial, switch or rescue treatment needs further investigation, and its interest in immunological non-responders, in severe immunosuppressed patients or in subjects harbouring non-R5 HIV-1 strains, remains to be addressed. Major concerns about their use still remain, including long-term tolerability, the risk of inducing an R5 to X4 switch, particularly in compartments other than blood, and the risk of interfering with some immune responses.

Implications of maraviroc and/or rapamycin in a mouse model of fragility.

BACKGROUND: As age increases, the risk of developing fragility also increases. Improving the knowledge of frailty could contribute to maintaining the functional ability of elderly people. Interleukin (IL)-10 homozygous knockout mice (IL-10tm/tm [IL10KO]) constitute an excellent tool for the study of frailty. Because patients with frailty demonstrate an overexpression of CCR5, rapamycin (RAPA) and/or maraviroc (MVC), two molecules able to decrease CCR5 expression, were evaluated. RESULTS: Muscle myostatin was reduced in all the therapeutic groups but the MVC group (p <0.001 for RAPA and MVC-RAPA) and in serum samples (p <0.01 for all the groups). Serum CK levels were also significantly lower in MVC and RAPA groups (p <0.01 in both cases). Lower AST levels were observed in all the therapeutic groups (p <0.05 for all of them). The apoptotic effector caspase-3 was significantly lower in MVC and RAPA groups (p<0.05 in both cases). Combined treatment with MVC-RAPA showed a synergistic increase in p-AKT, p-mTOR and SIRT1 levels. CONCLUSIONS: MVC and RAPA show a protective role in some factors involved in frailty. More studies are needed to prove their clinical applications. MATERIAL AND METHODS: Eighty male homozygous IL10KOs were randomly assigned to one of 4 groups (n= 20): i) IL10KO group (IL10KO); ii) IL10KO receiving MVC in drinking water (MVC group), iii) IL10KO receiving RAPA in drinking water (RAPA group), and finally, iv) MVC-RAPA group that received MVC and RAPA in drinking water. Blood and muscle samples were analysed. Survival analysis, frailty index calculation, and functional assessment were also performed.

The CCL5/CCR5 Axis in Cancer Progression.

Tumor cells can "hijack" chemokine networks to support tumor progression. In this context, the C-C chemokine ligand 5/C-C chemokine receptor type 5 (CCL5/CCR5) axis is gaining increasing attention, since abnormal expression and activity of CCL5 and its receptor CCR5 have been found in hematological malignancies and solid tumors. Numerous preclinical in vitro and in vivo studies have shown a key role of the CCL5/CCR5 axis in cancer, and thus provided the rationale for clinical trials using the repurposed drug maraviroc, a CCR5 antagonist used to treat HIV/AIDS. This review summarizes current knowledge on the role of the CCL5/CCR5 axis in cancer. First, it describes the involvement of the CCL5/CCR5 axis in cancer progression, including autocrine and paracrine tumor growth, ECM (extracellular matrix) remodeling and migration, cancer stem cell expansion, DNA damage repair, metabolic reprogramming, and angiogenesis. Then, it focuses on individual hematological and solid tumors in which CCL5 and CCR5 have been studied preclinically. Finally, it discusses clinical trials of strategies to counteract the CCL5/CCR5 axis in different cancers using maraviroc or therapeutic monoclonal antibodies.

Efficacy and safety of long-term maraviroc use in a heterogeneous group of HIV-infected patients: A retrospective cohort study.

Since the registration of maraviroc (MVC) as an antiretroviral agent in 2008, only studies with a follow-up time of <5 years have been published. Therefore, little is known about its long-term safety and efficacy in clinical practice. In this cohort study, data on long-term follow-up of MVC treatment in routine practice were analysed. A retrospective cohort study was conducted at University Medical Centre Utrecht with a follow-up period up to almost 10 years. The efficacy and tolerability of MVC-containing antiretroviral therapy (ART) was analysed in human immunodeficiency virus type 1 (HIV-1)-infected patients. The cohort consisted of 111 HIV patients who were treated for a median of 11.0 years (IQR 4.0-15.0 years) and with a median of 4 (IQR 2-6) previous ART regimens. The median time of MVC use was 49 months (IQR 21-82 months). Mean CD4+ T-cell counts continued to increase up to 9 years following initiation of MVC. Patients with a detectable viral load (≥50 copies/mL HIV-RNA) at the start of MVC-containing ART reached high proportions of viral suppression. Only three patients (2.7%) experienced treatment failure despite optimal therapy. Nine patients (8.1%) discontinued MVC owing to intolerance of their ART regimen. Severe laboratory abnormalities were deemed to be unrelated to MVC use. During the 487 person-years of follow-up, 18 patients (16.2%) died. MVC use in this heavily pre-treated cohort was generally well tolerated during long-term follow-up. Furthermore, use of MVC resulted in a good immunological and virological response in clinical practice.

Maraviroc reduces neuropathic pain through polarization of microglia and astroglia - Evidence from in vivo and in vitro studies.

Recent studies suggest that CCR5 and its ligands are important regulators for the development of neuropathic pain and that their modulation can have some beneficial properties. Therefore, the aim of our study was to investigate the influence of maraviroc (MVC, a CCR5 antagonist) on glial polarization markers and intracellular signaling pathways in the spinal cord 7 days after chronic constriction injury (CCI) to the sciatic nerve and in primary glial cultures after LPS stimulation. Our results demonstrated that chronic intrathecal administration of MVC diminished neuropathic pain symptoms and nociceptive threshold ∼60 min after drug administration on days 3 and 7 post-CCI. MVC downregulated the levels of phosphorylated p38 MAPK, ERK1/2 and NF-κB proteins in the spinal cord and upregulated STAT3 in the dorsal root ganglia (DRG). Additionally, using Western blot analysis, we demonstrated that MVC effectively diminished "classical" activation markers: IL-1ß, IL-18, IL-6 and NOS2 in the spinal cord. In contrast, MVC upregulated "alternative" antinociceptive activation markers: IL-1RA, IL-18BP and IL-10 in the spinal cord. In parallel, MVC downregulated the levels of phosphorylated p38 MAPK, ERK1/2 and NF-κB proteins and upregulated STAT3 in microglial and astroglial cell cultures. Similarly, MVC reduced pronociceptive (IL-1ß, IL-18, IL-6, NOS2) and enhanced the antinociceptive (IL-1RA, IL-18BP, IL-10) factors after LPS stimulation. Our studies provide new evidence that MVC attenuates neuropathy symptoms, promotes spinal glial "alternative" polarization and restores the balance between pro- and antinociceptive factors. Our results suggest the modulation of CCR5 by MVC as a novel therapeutic approach for neuropathy.

Off-label use of maraviroc in clinical practice.

Maraviroc is a first-in-class selective CCR5 antagonist only approved in combination with other antiretrovirals for the treatment of HIV-infection. However, sometimes, off-label prescribing is necessary. In this regard, interesting data have been obtained with maraviroc from studies using murine models. In human daily clinical practice there are many researching areas of interest where CCR5 could play an important role. Nowadays few clinical trials are evaluating maraviroc's role in non-HIV-infected patients but there are many open issues that need to be answered about CCR5 antagonists. In this article we review some of them.