CCR5 Antagonist Research Articles

Overcoming pancreatic cancer immune resistance by codelivery of CCR2 antagonist using a STING-activating gemcitabine-based nanocarrier

STING agonist has recently gained much attention for cancer treatment, but the therapeutic potential of STING agonist is hampered by STING-associated tumor immune resistance. In this work, guided by both bioinformatics and computer modeling, we rationally designed a “one stone hits two birds” nanoparticle-based strategy to simultaneously activate STING innate immune response while eliminating STING-associated immune resistance for the treatment of pancreatic ductal adenocarcinoma (PDAC). We discovered that the ultra-small sized micellar system based on gemcitabine-conjugated polymer (PGEM), which showed superior capacity of penetration in pancreatic tumor spheroid model and orthotopic tumor model, could serve as a novel “STING agonist”. The activation of STING signaling in dendritic cells (DCs) by PGEM increased both innate nature killer (NK) and adaptive anti-tumor T cell response. However, activation of STING signaling by PGEM in tumor cells also drove the induction of chemokines CCL2 and CCL7, resulting in immune resistance by recruiting tumor associated macrophage (TAM) and myeloid-derived suppressor cells (MDSCs). Through the combination of computer modeling and experimental screening, we developed a dual delivery modality by incorporating a CCR2 (the receptor shared by both CCL2 and CCL7) antagonist PF-6309 (PF) into PGEM micellar system. Our studies demonstrated that PGEM/PF formulation significantly reduced pancreatic tumor burden and induced potent anti-tumor immunity through reversing the CCL2/CCL7-mediated immunosuppression. Moreover, PGEM/PF sensitized PDAC tumors to anti-PD-1 therapy, leading to complete suppression/eradication of the tumors. Our work has shed light to the multi-faceted role of STING activation and provided a novel immunotherapy regimen to maximize the benefit of STING activation for PDAC treatment. In addition, this work paved a new way for bioinformatics and computer modeling-guided rational design of nanomedicine.

Structure-Based Design of Tropane Derivatives as a Novel Series of CCR5 Antagonists with Broad-Spectrum Anti-HIV-1 Activities and Improved Oral Bioavailability.

Blocking the entry of an HIV-1 targeting CCR5 coreceptor has emerged as an attractive strategy to develop HIV therapeutics. Maraviroc is the only CCR5 antagonist approved by FDA; however, serious side effects limited its clinical use. Herein, 21 novel tropane derivatives (6-26) were designed and synthesized based on the CCR5-maraviroc complex structure. Among them, compounds 25 and 26 had comparable activity to maraviroc and presented more potent inhibitory activity against a series of HIV-1 strains. In addition, compound 26 exhibited synergistic or additive antiviral effects in combination with other antiretroviral agents. Compared to maraviroc, both 25 and 26 displayed higher Cmax and AUC0-∞ and improved oral bioavailability in SD rats. In addition, compounds 25 and 26 showed no significant CYP450 inhibition and showed a novel binding mode with CCR5 different from that of maraviroc-CCR5. In summary, compounds 25 and 26 are promising drug candidates for the treatment of HIV-1 infection.

Nanotherapy: New Approach for Impeding Hepatic Cancer Microenvironment via Targeting Multiple Molecular Pathways.

Hepatocellular carcinoma (HCC) microenvironment has been recognized as a key contributor for cancer progression, metastasis, and drug resistance. The crosstalk between tumor cells, the vascular endothelial growth factor (VEGF), and the chemokine (C-C motif) ligand 2 (CCL2) signaling networks mediates immunoinhibitory impact and facilitates tumor angiogenesis. The current investigation aimed at exploring the potent anti-cancer activity of the newly designed nano-based anti-cancer therapy comprising anti-VEGF drug, avastin (AV), and CCR2 antagonist (CR) to counteract HCC and tracking its mode of action in vivo. The prepared AV, CR, and AVCR nanoprototypes were characterized by nanoscale characterization techniques in our previous work. Here, they are applied for unearthing their anti-cancer properties / mechanisms in hepatic cancer-induced rats via analyzing protein levels and genetic expression of the elements incorporated in the angiogenesis, apoptosis, and metastasis signalling pathways. The present results revealed a significant down-regulation in the angiogenesis, survival and metastasis indices along with up-regulation in the pro-apoptotic mediators upon treatment of hepatic cancer-bearing rats with the novel synthesized nanomaterials when compared with the untreated counterparts. We showed across HCC model that anti-VEGF in combination with CCR2 antagonism therapy leads to sensitization and enhanced tumor response over anti-VEGF or CCR2 antagonism monotherapy, particularly in its nanoscale formulation. The present approach provides new mechanistic insights into the powerful anti-hepatic cancer advantage of the novel nanoprototypes which is correlated with modulating critical signal transduction pathways implicated in tumor microenviroment such as angiogenesis, apoptosis and metastasis. This research work presents a substantial foundation for future studies focused on prohibiting cancer progression and recovery by targeting tumor microenviroment.

187P Phase I/II study of the oral CCR4 antagonist, FLX475, as monotherapy and in combination with pembrolizumab in advanced cancer

Preclinical studies with oral CCR4 antagonists have demonstrated inhibition of suppressive regulatory T cell (Treg) migration into the tumor microenvironment and antitumor efficacy. The FLX475-02 trial is a phase 1/2, open-label, dose-escalation and cohort expansion study to determine the safety and antitumor activity of the oral CCR4 antagonist FLX475 as monotherapy and in combination with pembrolizumab in subjects with several types of advanced cancer.

Targeted blocking of CCR2 and CXCR2 improves the efficacy of transarterial chemoembolization of hepatocarcinoma

BackgroundTransarterial chemoembolization (TACE) has been shown to prolong survival in patients with unresectable hepatocellular carcinoma (HCC); however, the long-term survival remains dismal. Targeting macrophage and neutrophil infiltration is a promising strategy. The CCL2/CCR2 and CXCLs/CXCR2 axes are required for recruitment of macrophages and neutrophils, respectively, in HCC. We investigated the feasibility of CCL2/CCR2 and CXCLs/CXCR2 as therapeutic targets in combination with TACE for treating HCC.MethodsExpression of CCL2/CCR2 and CXCLs/CXCR2 was analyzed in the primary rat HCC model and one HCC cohort. The relationship between expression levels, neutrophil and macrophage infiltration, hepatocarcinogenesis progression in the rat model, and survival of HCC patients was assessed. The anti-tumor effects of blocking the CCL2/CCR2 and CXCLs/CXCR2 axes by CCR2 and CXCR2 antagonists in combination with TACE were evaluated in HCC rats. The numbers of macrophages, neutrophils, and hepatic progenitor cells were further determined to explore the underlying mechanisms.ResultsHigh macrophage and neutrophil infiltration and CXCL8 expression were associated with poor prognosis in the TCGA liver cancer dataset. High expression of CCL2/CCR2 and CXCL8/CXCR2 in clinical HCC specimens was associated with reduced survival. Expression of CCL2/CCR2 and CXCL1/CXCR2 was correlated with hepatocarcinogenesis progression in the primary rat HCC model. Blockade of CCL2/CCR2 and CXCLs/CXCR2 enhanced the anti-tumor effect of TACE treatment in this model. Blocking the CCL2/CCR2 and CXCLs/CXCR2 axes with CCR2 and CXCR2 antagonists in TACE-treated rats reduced macrophage and neutrophil infiltration and hepatic progenitor cell activation and thus overcame TACE resistance in HCC.ConclusionsThe results demonstrate the translational potential of immunotherapy targeting the CCL2/CCR2 and CXCLs/CXCR2 axes in combination with TACE therapy for the treatment of HCC.

Rational Engineering of a Sub-Picomolar HIV-1 Blocker.

With the aim of rationally devising a refined and potent HIV-1 blocker, the cDNA of CCL5 5p12 5m, an extremely potent CCR5 antagonist, was fused to that of C37, a gp41-targeted fusion inhibitor. The resulting CCL5 5p12 5m-C37 fusion protein was expressed in E. coli and proved to be capable of inhibiting R5 HIV-1 strains with low to sub-picomolar IC50, maintaining its antagonism toward CCR5. In addition, CCL5 5p12 5m-C37 inhibits R5/X4 and X4 HIV-1 strains in the picomolar concentration range. The combination of CCL5 5p12 5m-C37 with tenofovir (TDF) exhibited a synergic effect, promoting this antiviral cocktail. Interestingly, a CCR5-targeted combination of maraviroc (MVC) with CCL5 5p12 5m-C37 led to a synergic effect that could be explained by an extensive engagement of different CCR5 conformational populations. Within the mechanism of HIV-1 entry, the CCL5 5p12 5m-C37 chimera may fit as a powerful blocker in several instances. In its possible consideration for systemic therapy or pre-exposure prophylaxis, this protein design represents an interesting lead in the combat of HIV-1 infection.

A CCR5 antagonist, maraviroc, alleviates neural circuit dysfunction and behavioral disorders induced by prenatal valproate exposure

BackgroundValproic acid (VPA) is a clinically used antiepileptic drug, but it is associated with a significant risk of a low verbal intelligence quotient (IQ) score, attention-deficit hyperactivity disorder and autism spectrum disorder in children when it is administered during pregnancy. Prenatal VPA exposure has been reported to affect neurogenesis and neuronal migration and differentiation. In addition, growing evidence has shown that microglia and brain immune cells are activated by VPA treatment. However, the role of VPA-activated microglia remains unclear.MethodsPregnant female mice received sodium valproate on E11.5. A microglial activation inhibitor, minocycline or a CCR5 antagonist, maraviroc was dissolved in drinking water and administered to dams from P1 to P21. Measurement of microglial activity, evaluation of neural circuit function and expression analysis were performed on P10. Behavioral tests were performed in the order of open field test, Y-maze test, social affiliation test and marble burying test from the age of 6 weeks.ResultsPrenatal exposure of mice to VPA induced microglial activation and neural circuit dysfunction in the CA1 region of the hippocampus during the early postnatal periods and post-developmental defects in working memory and social interaction and repetitive behaviors. Minocycline, a microglial activation inhibitor, clearly suppressed the above effects, suggesting that microglia elicit neural dysfunction and behavioral disorders. Next-generation sequencing analysis revealed that the expression of a chemokine, C–C motif chemokine ligand 3 (CCL3), was upregulated in the hippocampi of VPA-treated mice. CCL3 expression increased in microglia during the early postnatal periods via an epigenetic mechanism. The CCR5 antagonist maraviroc significantly suppressed neural circuit dysfunction and post-developmental behavioral disorders induced by prenatal VPA exposure.ConclusionThese findings suggest that microglial CCL3 might act during development to contribute to VPA-induced post-developmental behavioral abnormalities. CCR5-targeting compounds such as maraviroc might alleviate behavioral disorders when administered early.

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.

C[sbnd]C 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-β-, 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-β, 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-β+, 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.

CCR1 antagonist J-113863 corrects the imbalance of pro- and anti-inflammatory cytokines in a SJL/J mouse model of relapsing-remitting multiple sclerosis

Multiple sclerosis (MS), an immune-mediated and neurodegenerative disorder of the central nervous system (CNS), is characterized by infiltrating myelin-reactive T lymphocytes and demyelinating lesions. Experimental autoimmune encephalomyelitis (EAE) is a well-established animal model used to study MS. To explore the impact of chemokine receptor CCR1 blockade in EAE and the underlying mechanisms, we used CCR1 antagonist J-113863 in PLP139-151-induced EAE in SJL/J mice. Following EAE induction, mice were treated with J-113863 (10 mg/kg) daily from day 14 until day 25. We investigated the effect of J-113863 on expression levels of GM-CSF, IL-6, IL-10, IL-27 in CD4+ spleen cells, using flow cytometry. We also analyzed the effect of J-113863 on GM-CSF, IL-6, IL-10, IL-27 mRNA and protein expression levels using RT-PCR and Western blot analysis in brain tissues. J-113863 treatment decreased the populations of CD4+GM-CSF+ and CD4+IL-6+ cells and increased CD4+IL-27+ and CD4+IL-10+ cells in the spleen. J-113863 had a suppressive effect on the mRNA and protein expression levels of GM-CSF, and IL-6 in the brain tissue. On the other hand, J-113863 treatment increased the mRNA and protein expression of IL-10 and IL-27 in the brain tissue. Our results highlighted J-113863′s potential role in suppressing pro-inflammatory expression and up-regulating anti-inflammatory mediators, which could represent a beneficial alternative approach to MS treatment.

Characterization of Impurities in Reverse Transcriptase Inhibitors by Profiling Techniques

There has been ever growing activity in impurities existing in pharmaceutical products as well as bulk drugs. According to a range of regulatory authorities, no longer solely purity profiles, however additionally impurity profiles, are now required. The technique facts for an individual impurity’s organic safety are recognized as impurity profiling. The many developments in analytical viewpoints of impurity profiling of anti-retroviral (ARV) medicines and products used to deal with human immunodeficiency virus (HIV) infections are described in this review. ARVs work using inhibiting unique ranges of the viral contamination cycle to produce therapeutic benefits. Thus, drug classes are stratified as nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs/NTRTIs), non-NRTIs (NNRTIs), integrase strand transfer inhibitors, CCR5 antagonists, viral fusion inhibitors, and protease inhibitors (PIs). In this overview predominant focal point given on class that is reverse transcriptase inhibitors (RTIs). The wide variety of papers dealing with ARV drug impurity profiling is developing at an alarming pace. The cutting-edge overview article, which is based primarily on publications posted in the closing 15 years, tries to provide vast data concerning RTIs drug impurity profiling. RTIs which are labeled into two sub-categories, that is, NRTIs and NNRTIs. NRTIs pressure the HIV virus to use erroneous variations of building block, so contaminated cells cannot make more HIV and NNRTIs these are additionally referred to as “non-nukes.” NNRTIs bind to a precise protein so the HIV virus cannot make copies of itself. The investigatory overview might also furnish the complete important points to the researchers who are working in the region of impurity profiling of RTIs. To the most tremendous of our information, no overview until date noted to center of attention on impurity profiling of RTIs.

Abstract 6370: Assessing the effect of blocking CCL2-CCR2 axis on breast cancer brain metastasis

Abstract Among the 300,000 newly diagnosed breast cancer patients every year, 5~20% of them will develop symptomatic brain metastasis, whose 1-year survival rate is lower than 20%. Our group previously reported that brain tumor microenvironment (TME)-mediated PTEN downregulation in brain metastatic tumor cells increases the secretion of the chemokine CCL2, which enhances the infiltration of CCR2+ bone marrow derived myeloid cells, eventually promoting brain metastasis outgrowth. However, the mechanism of CCL2-CCR2 axis promoting brain metastasis is not clear, and the efficacy of targeting either CCR2 or CCL2 remained to be assessed. Here we show that Ccr2 antagonism significantly blocked Ccr2high myeloid cells trafficking in the blood and infiltration into the brain TME. However, Ccr2 antagonism did not sufficiently impede breast cancer brain metastasis in multiple preclinical models. Nevertheless, knocking down CCL2 or targeting CCL2 exhibited significant inhibition of brain metastasis growth. Subsequent analysis of the brain TME through mass cytometry demonstrated dramatically decreased infiltration of both Ccr2high and Ccr2low myeloid cell populations in the CCL2 targeted group, implying that the Ccr2low myeloid cells are also involved in promoting brain metastasis growth. Our data highlights the differential responses between targeting CCR2 or CCL2 in multiple preclinical brain metastasis models, which direct us to explore the function of Ccr2low myeloid cells in regulating brain metastasis progression. Our findings also suggest that carefully choosing between CCR2 or CCL2 as a target to control brain metastasis is important in clinical practice. Citation Format: Yimin Duan, Yutao Qi, Lin Zhang, Xiangliang Yuan, Dihua Yu. Assessing the effect of blocking CCL2-CCR2 axis on breast cancer brain metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6370.

Abstract 6162: Histone deacetylase inhibitor modulates T cell recruitment to metastatic pancreatic neuroendocrine tumors by CCR5 regulation

Abstract Pancreatic neuroendocrine tumors (PNETS) represent the second most common pancreatic neoplasm with surgical resection serving as the mainstay of treatment for localized PNETs (lPNETs) > 2 cm in size; however, therapeutic options for managing metastatic PNETs (mPNETs) remain limited. Recently, immunotherapy with checkpoint inhibitors has emerged as effective therapy across a range of malignancies but has shown limited efficacy in PNET patients partly due to what has been reported as a “cold” tumor microenvironment (TME). Here, we aimed to characterize the TME among both localized and mPNETs and identify mechanisms to increase tumor immunogenicity and T cell recruitment among these patients. We analyzed tumor-infiltrating and peripheral T cells from patients with lPNETs and mPNETs by flow cytometry and found higher expression of CD69+ (activation), CCR5+ (recruitment), and PD1+ (exhaustion) in T cells isolated from TME compared to peripheral blood. Further, we identified a more profound degree of CD3+ and CD8+ T cell infiltration among mPNETs compared to lPNETs by immunohistochemistry analysis, suggesting that mPNETs are at least moderately enriched with activated T cells. RNA-sequencing performed on 22 sporadic, well-differentiated primary PNETs revealed distinct transcriptional signatures dependent upon metastatic potential. These divergent transcriptomes were analyzed by an L1000 computational algorithm, which classifies landmark gene signatures perturbed by drug treatments. We identified the histone deacetylase inhibitor vorinostat as the drug most likely to perturb the PNET gene signature. A KEGG pathway analysis revealed that these vorinostat-target genes were commonly involved in both Th1, Th2, and Th17 cell differentiation and in the NF-κB pathway. Vorinostat treatment of patient-derived mPNET resulted in increased T cell migration towards metastatic tumors across a semi-permeable membrane; cotreatment with a competitive CCR5 antagonist abrogated this effect. In addition, vorinostat treatment of BON-1 and QGP-1, two PNET cell lines, elevated both NF-κB activity and CCR5 expression, with induction reduced following inhibition of NF-κB nuclear localization. Our study demonstrates that T cell recruitment toward mPNET tissue is dependent upon CCR5 expression. These results reveal that PNET TME is regulatable by vorinostat and opens an avenue of potential sensitization to immune checkpoint blockade among patients with PNETs. Citation Format: Jacques A. Greenberg, Jessica N. Limberg, Akanksha Verma, David Kim, Maureen D. Moore, Timothy M. Ullmann, Jessica W. Thiesmeyer, Zachary Loewenstein, Kevin J. Chen, Caitlin E. Egan, Dessislava I. Stefanova, Rohan Bareja, Rasa Zarnegar, Brendan M. Finnerty, Theresa Scognamiglio, Olivier Elemento, Thomas J. Fahey, Irene M. Min. Histone deacetylase inhibitor modulates T cell recruitment to metastatic pancreatic neuroendocrine tumors by CCR5 regulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6162.

A Common Variant at the 3'untranslated Region of the CCL7 Gene (rs17735770) Is Associated With Decreased Susceptibility to Coronary Heart Disease.

Monocytes participate in the development of atherosclerosis through the action of cytokines and other inflammatory mediators. Among them, CCR2 and its ligands, CCL2 and CCL7 play an important role, so the main objective of this work was to determine whether genetic variants affecting their activity were associated with cardiovascular disease. A cohort of 519 patients that have suffered coronary events was analyzed under a propensity score-matching protocol selecting a homogeneous set of cases and controls, according to age, sex, smoking status, dyslipidemia, arterial hypertension and type 2 diabetes as risk factors. While dyslipidemia and arterial hypertension were more prevalent among patients with angina pectoris, current smoking status and elevated inflammatory markers, including total leukocyte and monocyte counts, were more likely associated with acute coronary events. Propensity score matching analysis, performed to eliminate the influence of these risk factors and highlight genetic modifiers, revealed that a single nucleotide variant, rs17735770 at the 3'untranslated region of the CCL7 gene transcript, was associated with decreased cardiovascular risk in a group represented mostly by men, with an average age of 57, and without significant differences in traditional risk factors. Furthermore, the presence of this variant altered the local mRNA structure encompassing a binding site for miR-23ab, resulting in increased translation of a reporter gene in a miR23 independent fashion. The rs17735770 genetic variant led to increased expression of CCL7, a potential antagonist of CCR2 at inflammatory sites, where it could play a meaningful role during the evolution of atherosclerosis.

The Chemokine (C-C Motif) Receptor 2 Antagonist INCB3284 Reduces Fluid Requirements and Protects From Hemodynamic Decompensation During Resuscitation From Hemorrhagic Shock.

OBJECTIVES:Clinical correlations suggest that systemic chemokine (C-C motif) ligand (CCL) 2 release may contribute to blood pressure regulation and the development of hemodynamic instability during the early inflammatory response to traumatic-hemorrhagic shock. Thus, we investigated whether blockade of the principal CCL2 receptor chemokine (C-C motif) receptor (CCR) 2 affects blood pressure in normal animals, and hemodynamics and resuscitation fluid requirements in hemorrhagic shock models.DESIGN:Randomized prospective treatment study.SETTING:University laboratory.SUBJECTS:Male Sprague-Dawley rats.INTERVENTIONS:First, treatment of healthy anesthetized rats with increasing doses of INCB3284 or vehicle. Second, rats were hemorrhaged for 30 minutes, followed by treatment with the CCR2 antagonist INCB3284 (1.1 and 5.5 μmol/kg), the CCR5 antagonist Maraviroc (=control, 5.5 μmol/kg) or vehicle, and subsequent fluid resuscitation to maintain blood pressure until t = 90 minutes. Third, treatment of rats with 5 μmol/kg INCB3284 or vehicle after hemorrhage and fluid resuscitation until t = 300 minutes.MEASUREMENTS AND MAIN RESULTS:INCB3284 did not affect intrinsic function of isolated rat resistance arteries in pressure myography experiments. Blood pressure in anesthetized vehicle-treated animals continuously decreased by 0.09 ± 0.01 mm Hg/min (p < 0.001) but remained constant after INCB3284 injections. Systemic concentrations of the CCR2 agonists CCL2, CCL5, and CCL11 increased during hemorrhage and fluid resuscitation. INCB3284 dose-dependently reduced fluid requirements by 58% ± 11% in short-term experiments, whereas Maraviroc and vehicle-treated animals were indistinguishable. When resuscitation was performed until t = 300 minutes, INCB3284 reduced fluid requirements by 62% ± 6%, prevented from hemodynamic decompensation, reduced mortality from 50% with vehicle treatment to zero, and reduced overall tissue wet-weight/dry-weight ratios.CONCLUSIONS:Our findings suggest that CCR2 is involved in the regulation of normal cardiovascular function and during the cardiovascular stress response to hemorrhagic shock and fluid resuscitation. The present study identifies CCR2 as a drug target to reduce fluid requirements and to prevent death from hemodynamic decompensation during resuscitation from hemorrhagic shock.

CCR4 and CCR5 Involvement in Monocyte-Derived Macrophage Migration in Neuroinflammation.

Microglia, resident macrophages in the brain, play major roles in neuroinflammation after an acute many neurological diseases, including stroke. Our recent animal stroke model showed that interleukin (IL)-4 and IL-13 released by microglia are converted into monocyte-derived macrophages. However, the correlation with the migration mechanism of these cells is still unclear. This study aimed to clarify the effect of these cells on their migration and to identify potential targets that influence neuroinflammatory conditions. Inflammatory conditions were induced by lipopolysaccharide (LPS) treatment in in vitro and in vivo models. Cell migration was observed using transwell assay, and target chemokines were screened using the proteome profiler array in the in vitro model. Intravital, IVIS, and CLARITY imaging were used in the in vivo model. After LPS (1 ng/ml) treatment in BV2 (microglia cell line) and J774 (monocyte/macrophage cell line) cells, BV2 migration was approximately two-fold more enhanced compared to J774 migration. Overall, six types of chemokine C-C motif ligands (CCLs) were detected from the BV2 conditioned medium with LPS. These CCLs were related to C-C motif receptor (CCR)4 and CCR5. In the in vivo model, CCR4 and CCR5 antagonist significantly inhibited the migration of monocyte-derived macrophages to brain tissue following LPS (5 µg) treatment. In conclusion, the chemokines released by microglia may influence migration of monocyte-derived macrophages in necroinflammation conditions inducted by microglial activation. CCR4 and CCR5 expressed on monocyte-derived macrophages interacted with these chemokines and induced migration. Therefore, CCR4 and CCR5 may be explored as new therapeutic targets for neuroinflammation.

Chemokine Receptor Antagonism Decreases Drug Choice and Modifies Opioid Analgesia in Rats

Substance use disorders (SUDs) and overdose deaths have reached unprecedented levels despite considerable efforts to develop pharmacotherapies for their treatment and prevention. Chemoattractant cytokines (‘chemokines’) are immune system messengers that can alter the therapeutic and abuse‐related effects of opioids and stimulants. Therefore, the aims of this study were to evaluate the effectiveness of Maraviroc, a CCR5 antagonist, and AMD3100, a CXCR4 antagonist, to alter 1) the self‐administration of fentanyl, an opioid, and cocaine, a stimulant, using a food versus drug choice procedure and 2) the analgesic effects of fentanyl in a radiant heat assay. Adult male Sprague Dawley rats were trained to respond under a fixed ratio (FR) 5 on one lever to receive an infusion of fentanyl (n=8), and on an alternate lever to receive food (grain‐based pellet). The choice procedure consisted of 5 sequential 20‐min components, each separated by a 2‐min intercomponent interval. Food was available across all five components, with increasing unit doses of fentanyl (0.00032‐0.01 mg/kg/infusion) available during components 2‐5; no drug was available during component 1. Once responding stabilized, rats underwent a series of drug pretreatment tests, including: naloxone (1, 3.2 mg/kg; IP), haloperidol (0.01‐0.1 mg/kg; IP), Maraviroc (1‐17.8 mg/kg; IP), and AMD3100 (1‐17.8 mg/kg; IP). A separate cohort of 8 adult male Sprague Dawley rats was used to evaluate the effects of Maraviroc (10 mg/kg; IP), and AMD3100 (10 mg/kg; IP), on paw withdrawal latencies in a thermal nociception procedure following cumulative doses of fentanyl (0.01‐0.1 mg/kg; IP). In rats responding for food or fentanyl, naloxone reduced fentanyl choice while increasing choice of food, whereas haloperidol had little effect on the choice for fentanyl, but decreased responding on both levers at large doses. Maraviroc and AMD3100 had similar effects all rats tested, effectively reallocating behavior away from the drug and towards the food reinforcer. At the largest dose tested, Maraviroc (17.8 mg/kg; IP) disrupted behavior in the early portions of the session, suggestive of a sedative effect in some animals. Maraviroc and AMD3100 did not significantly modify the analgesic effects of fentanyl during tests of thermal nociception. These data suggest that antagonism of CXCR4 and CCR5 may be of use in the ongoing effort to develop medications for the treatment of SUDs.

Does Macrophage Stimulation by CCL5 Alter Melanoma Migratory Behavior?

BackgroundCCL5 (RANTES, regulated upon activation, normal T‐cell expressed and secreted) is secreted not only by T‐cells, but also by melanoma cells into the tumor microenvironment. The current project is part of a bigger effort by our laboratory to determine how the stimuli present in the tumor microenvironment may contribute to the progression of melanoma. Here, we explore CCL5 receptor expression on monocytes, macrophages, and melanoma cells, and whether endogenous or exogenous CCL5 stimulation of THP‐1 macrophages produce phenotypical changes that affect melanoma migratory behavior.MethodsWe used WM278 and LM‐Mel‐45 melanoma cells and THP‐1 monocytes before and after conversion to macrophages by 2 days exposure to 50 ng/ml PMA. To examine expression of the 3 key CCL5 receptors, we compared median fluorescence intensity (MFI) of antibody‐exposed cells to MFI of unlabeled cells using antibodies for CCR1, CCR3, and CCR5. We gated out debris and multiples, corrected for spillover, and analyzed the samples on a Bio‐Rad S3e cell sorter. We used recombinant CCL5 (100 ng/ml), the CCR1 &amp; CCR3 receptor antagonist, UCB35625 (100 nM) and the CCR5 antagonist, maraviroc (100 ng/ml). Melanoma migration rate was measured by a 16 h wound‐closure assay. Treatments included: Control, CCL5 only, maraviroc only, UCB35625 only, maraviroc and UCB35625 together, and CCL5 plus both blockers. Wound closure of LM‐Mel‐45 melanoma alone, a 1:4 mixture of macrophages to melanoma, or LM‐Mel‐45 melanoma treated with macrophage‐conditioned medium were compared in each treatment condition.ResultsCCL5 receptor expression was not found on WM278 melanoma cells. LM‐Mel‐45 melanoma express CCR1 but not CCR3 or CCR5. CCR1 and CCR5, but not CCR3, are expressed by both THP‐1 monocytes and THP‐1 macrophages. Melanoma cells alone or when co‐cultured with previously treated macrophages migrated at 14.3 ± 0.4 μm/h, but neither CCL5 stimulation nor receptor blockade changed migration significantly. When LM‐Mel‐45 melanoma cells were treated with conditioned macrophage medium, velocity increased to 16.8 ± 0.7 μm/h.ConclusionsThis work suggests that CCL5 does not directly impact melanoma migration either by endogenous expression or by exogenous addition. Even in the presence of CCL5 or antagonist‐exposed macrophages, we found no phenotypical changes that altered the physical interactions of macrophages on melanoma migratory rate. There is a small but significant increase in velocity of melanoma cells when treated with conditioned macrophage medium.

Blocking the entry of HIV into host cells through co‐receptor inhibition

The goal of our project is to synthesize a dual CXCR4/CCR5 co‐receptor inhibitor to block the entry of HIV into host cells.In the early phase of the HIV‐1 replication cycle, HIV‐1 binds to host cells through the CD4 protein present on the host cell surface. To infect the cell, HIV‐1 requires further interactions that promote fusion of the viral and cellular membranes. This can occur through binding to the chemokine co‐receptors such as CXCR4 and CCR5. We are choosing dual inhibition since under selective pressure of a CCR5 antagonist, CXCR4‐using strains have been shown to predominate. Through dual inhibition, we want to account for a possible resistance development that could occur when inhibiting only one of the two co‐receptors.Using a computational screen, a compound predicted to bind to both CCR5 and CXCR4 was identified (Hit 1). We established a reaction scheme to synthesize an analog of this compound (target compound 4) through solid phase peptide synthesis (Scheme 1). We completed the synthesis of compound 4 and we confirmed the addition of the first two amino acids (Fmoc‐phenylalanine and Fmoc‐proline) through LC‐MS and HPLC.We are currently expecting LC‐MS and HPLC results for the rest of the synthesis steps. Before the time of presentation, we plan to use our established methodology to synthesize multiple analogs through varying amino acids and evaluate them for biological activity. The goal of synthesizing analogs is to optimize CXCR4/CCR5 dual inhibition.

Science, Medicine, and the Anesthesiologist

Science, Medicine, and the Anesthesiologist