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In recent years fifteen 5,6-dihydro-α-pyrone derivatives, bearing either a distinctive cyclopropane or furan ring and named brevipolides A–O (1–15), have been isolated from the invasive plant Hyptis brevipes Poit. Their fascinating structural features, and the potent biological activities, including cytotoxicity against an array of human cancer cell lines and inhibition of the chemokine receptor CCR5, make them attractive synthetic targets. This review article highlights the recent synthetic methodologies and briefly summarizes their biological activities.

C-C chemokine receptor 5 (CCR5) is a major co-receptor molecule used by HIV-1 to enter cells. Two X-ray crystallographic studies are presented of the antibody RoAb13, which binds to the peptide PIYDIN, which is part of the N-terminal domain of CCR5. The results may provide the basis for active immunization vaccines to stimulate an antibody response to native CCR5 that will block HIV infection., C-C chemokine receptor 5 (CCR5) is a major co-receptor molecule used by HIV-1 to enter cells. This led to the hypothesis that stimulating an antibody response would block HIV with minimal toxicity. Here, X-ray crystallographic studies of the anti-CCR5 antibody RoAb13 together with two peptides were undertaken: one peptide is a 31-residue peptide containing the PIYDIN sequence and the other is the PIDYIN peptide alone, where PIYDIN is part of the N-terminal region of CCR5 previously shown to be important for HIV entry. In the presence of the longer peptide (the complete N-terminal domain), difference electron density was observed at a site within a hypervariable CDR3 binding region. In the presence of the shorter core peptide PIYDIN, difference electron density is again observed at this CDR3 site, confirming consistent binding for both peptides. This may be useful in the design of a new biomimetic to stimulate an antibody response to CCR5 in order to block HIV infection.

The chemokine receptor CCR5 plays a vital role in immune surveillance and inflammation. However, molecular details that govern its endogenous chemokine recognition and receptor activation remain elusive. Here we report three cryo-electron microscopy structures of Gi1 protein-coupled CCR5 in a ligand-free state and in complex with the chemokine MIP-1α or RANTES, as well as the crystal structure of MIP-1α-bound CCR5. These structures reveal distinct binding modes of the two chemokines and a specific accommodate pattern of the chemokine for the distal N terminus of CCR5. Together with functional data, the structures demonstrate that chemokine-induced rearrangement of toggle switch and plasticity of the receptor extracellular region are critical for receptor activation, while a conserved tryptophan residue in helix II acts as a trigger of receptor constitutive activation., The chemokine receptor CCR5 plays multiple roles in the immune system. Here, structures of Gi1 protein-coupled CCR5 with or without a chemokine bound and of the CCR5- chemokine MIP-1 α complex offer insight into the distinct binding modes of the ligands and into the mechanism of CCR5 activation.

In the absence of a prophylactic vaccine, the use of antiretroviral therapy (ART) as pre-exposure prophylaxis (PrEP) to prevent HIV acquisition by uninfected individuals is a promising approach to slowing the epidemic, but its efficacy is hampered by incomplete patient adherence and ART-resistant variants. Here, we report that competitive inhibition of HIV Env-CCR5 binding via the CCR5-specific antibody Leronlimab protects rhesus macaques against infection following repeated intrarectal challenges of CCR5-tropic SHIVSF162P3. Injection of Leronlimab weekly at 10 mg/kg provides significant but partial protection, while biweekly 50 mg/kg provides complete protection from SHIV acquisition. Tissue biopsies from protected macaques post challenge show complete CCR5 receptor occupancy and an absence of viral nucleic acids. After Leronlimab washout, protected macaques remain aviremic, and adoptive transfer of hematologic cells into naïve macaques does not transmit viral infection. These data identify CCR5 blockade with Leronlimab as a promising approach to HIV prophylaxis and support initiation of clinical trials., CCR5 is a co-receptor for many transmitted HIV strains. Here, the authors show that biweekly injection of the CCR5-specific antibody Leronlimab protects rhesus macaques against infection following repeated intrarectal challenges of a CCR5-tropic SHIV.

CCR5-delta 32 homozygous stem cell transplantation for HIV-infected individuals is being treated as a milestone in the global AIDS epidemic. Since 2008, when the second Berlin patient was cured from HIV after undergoing transplantation from a donor with delta-32 mutation, scientists are aiming for a long-term cure for the wider population. In 2019, a London patient became the second person to be free of HIV and came off the antiretroviral drugs completely. CCR5 gene is now being treated as a viable target for HIV treatment. It can be used in the treatment of HIV either through administration of drugs that bind to CCR5 and stop the receptor from working or through gene therapy to alter the CCR5 gene using CRISPR/Cas9 and prevent protein production. This review article aims to identify the obstacles and the need to overcome them in order to bridge the gap between current research and future potential cures for HIV.

CCR5 is the main HIV co-receptor. We aimed to (1) compare CCR5 expression on immune cells between people living with HIV (PLHIV) using combination antiretroviral therapy (cART) and HIV-uninfected controls, (2) relate CCR5 expression to viral reservoir size and (3) assess determinants of CCR5 expression. This cross-sectional study included 209 PLHIV and 323 controls. Percentages of CCR5+ cells (%) and CCR5 mean fluorescence intensity assessed by flow cytometry in monocytes and lymphocyte subsets were correlated to host factors, HIV-1 cell-associated (CA)-RNA and CA-DNA, plasma inflammation markers and metabolites. Metabolic pathways were identified. PLHIV displayed higher percentages of CCR5+ monocytes and several CD8+ T cell subsets, but lower percentages of CCR5+ naive CD4+ T cells and regulatory T cells (Tregs). HIV-1 CA-DNA and CA-RNA correlated positively with percentages of CCR5+ lymphocytes. Metabolome analysis revealed three pathways involved in energy metabolism associated with percentage of CCR5+ CD8+ T cells in PLHIV. Our results indicate that CCR5 is differently expressed on various circulating immune cells in PLHIV. Hence, cell-trafficking of CD8+ T cells and Tregs may be altered in PLHIV. Associations between energy pathways and percentage of CCR5+ CD8+ T cells in PLHIV suggest higher energy demand of these cells in PLHIV.

The process of luteal regression is tightly regulated by the immune system and chemokines-small cytokines responsible mostly for the activation and migration of immune cells. The role of chemokines in porcine corpus luteum (CL) function is still not well understood. The aim of this study was to investigate the expression profile and distribution of CC chemokines in the porcine CL during the natural oestrous cycle and early pregnancy. Additionally, the effect of PGF2α on the expression of selected chemokines and their luteotropic and apoptotic influence on CL cells were studied in vitro. The expression levels of the chemokines CCL2, CCL4, and CCL5 and the chemokine receptor CCR5 were time-dependent (low on Days 8-10 and high on Days 12-14 of the oestrous cycle). Moreover, CCL8 and CCR2 transcript levels were also elevated during the period of luteolysis. The immunolocalization of CCL2, CCL4, CCL5, CCR1, CCR2 and CCR5 was determined using CL sections obtained from cycling and pregnant pigs. The immunofluorescence signals were localized mainly in luteal cells. PGF2α treatment of CL cells caused increased mRNA expression of CCL2 and CCR1. CCL2 treatment alone upregulated the expression of genes BAX, BCL2 and StAR in CL cells in vitro, but additional experiments showed that the chemokines CCL2, CCL4 and CCL5 alone do not cause apoptosis in a mixed population of CL cells. The chemokine CCL4 increased the transcript levels of StAR and HSD3-β1. Additionally, CCL5 led to the inhibition of BAX gene expression. The differential spatiotemporal expression of CCL2, CCL4, CCL5 and CCR5 throughout the oestrous cycle and the direct but aberrant effect of these three chemokines on genes associated with apoptosis and progesterone synthesis indicate the complicated involvement of these factors in the regulation of luteolysis in pigs.

HIV-1 envelope glycoprotein [Env; trimeric (gp160)(3) cleaved to (gp120/gp41)(3)] attaches the virion to a susceptible cell and induces fusion of viral and cell membranes to initiate infection. It interacts with the primary receptor CD4 and coreceptor (e.g., chemokine receptor CCR5 or CXCR4) to allow viral entry by triggering large structural rearrangements and unleashing the fusogenic potential of gp41 to induce membrane fusion. Recent advances in structural biology of HIV-1 Env and its complexes with the cellular receptors have revealed molecular details of HIV-1 entry and yielded new mechanistic insights. In this review, I summarize our latest understanding of the HIV-1 membrane fusion process and discuss possible pathways for productive viral entry.

The chemokine receptor CCR5 is expressed on multiple cell types, including macrophages, dendritic cells, and T cells, and is the major co-receptor used during HIV transmission. Using a standard αCD3/CD28in vitrostimulation protocol to render CD4+ T cells from PBMCs permissive to HIV infection, we discovered that the percentage of CCR5+T cells was significantly elevated in CD4+ T cells when stimulated in the presence of peripheral blood mononuclear cells (PBMCs) as compared to when stimulated as purified CD4+ T cells. This indicated that environmental factors unique to the T-PBMCs condition affect surface expression of CCR5 on CD4+ T cells. Conditioned media from αCD3/CD28-stimulated PBMCs induced CCR5 expression in cultures of unstimulated cells. Cytokine profile analysis of these media suggests IL-12 as an inducer of CCR5 expression. Mass cytometric analysis showed that stimulated T-PBMCs exhibited a uniquely activated phenotype compared to T-Pure. In line with increased CCR5 expression and activation status in stimulated T-PBMCs, CD4+ T cells from these cultures were more susceptible to infection by CCR5-tropic HIV-1 as compared with T-Pure cells. These results suggest that in order to increaseex vivoinfection rates of blood-derived CD4+ T cells, standard stimulation protocols used in HIV infection studies should implement T-PBMCs or purified CD4+ T cells should be supplemented with IL-12.

CCR5 plays a central role in infectious disease, host defense, and cancer progression, thereby making it an ideal target for therapeutic development. Notably, CCR5 is the major HIV entry co-receptor, where its surface density correlates with HIV plasma viremia. The level of CCR5 receptor occupancy (RO) achieved by a CCR5-targeting therapeutic is therefore a critical predictor of its efficacy. However, current methods to measure CCR5 RO lack sensitivity, resulting in high background and overcalculation. Here, we report on two independent, flow cytometric methods of calculating CCR5 RO using the anti-CCR5 antibody, Leronlimab. We show that both methods led to comparable CCR5 RO values, with low background on untreated CCR5+CD4+ T cells and sensitive measurements of occupancy on both blood and tissue-resident CD4+ T cells that correlated longitudinally with plasma concentrations in Leronlimab-treated macaques. Using these assays, we found that Leronlimab stabilized cell surface CCR5, leading to an increase in the levels of circulating and tissue-resident CCR5+CD4+ T cells in vivo in Leronlimab-treated macaques. Weekly Leronlimab treatment in a chronically SIV-infected macaque led to increased CCR5+CD4+ T cells levels and fully suppressed plasma viremia, both concomitant with full CCR5 RO on peripheral blood CD4+ T cells, demonstrating that CCR5+CD4+ T cells were protected from viral replication by Leronlimab binding. Finally, we extended these results to Leronlimab-treated humans and found that weekly 700 mg Leronlimab led to complete CCR5 RO on peripheral blood CD4+ T cells and a statistically significant increase in CCR5+CD4+ T cells in peripheral blood. Collectively, these results establish two RO calculation methods for longitudinal monitoring of anti-CCR5 therapeutic antibody blockade efficacy in both macaques and humans, demonstrate that CCR5+CD4+ T cell levels temporarily increase with Leronlimab treatment, and facilitate future detailed investigations into the immunological impacts of CCR5 inhibition in multiple pathophysiological processes.

Influenza A virus (IAV) is the main etiological agent of acute respiratory tract infections. During IAV infection, interferon triggers the overexpression of restriction factors (RFs), the intracellular antiviral branch of the innate immune system. Conversely, severe influenza is associated with an unbalanced pro-inflammatory cytokine release. It is unclear whether other cytokines and chemokines released during IAV infection modulate RFs to control virus replication. Among the molecules enhanced in the infected respiratory tract, ligands of the CCR5 receptor play a key role, as they stimulate the migration of inflammatory cells to the alveoli. We investigated here whether ligands of the CCR5 receptor could enhance RFs to levels able to inhibit IAV replication. For this purpose, the human alveolar basal epithelial cell line (A549) was treated with endogenous (CCL3, CCL4 and CCL5) or exogenous (HIV-1 gp120) ligands prior to IAV infection. The three CC-chemokines tested reduced infectious titers between 30% to 45% upon 24 hours of infection. Eploying RT-PCR, a panel of RF mRNA levels from cells treated with CCR5 agonists was evaluated, which showed that the SAMHD1 expression was up-regulated four times over control upon exposure to CCL3, CCL4 and CCL5. We also found that IAV inhibition by CCL5 was dependent on PKC and that SAMHD1 protein levels were also increased after treatment with CCL5. In functional assays, we observed that the knockdown of SAMHD1 resulted in enhanced IAV replication in A549 cells and abolished both CCL5-mediated inhibition of IAV replication and CCL5-mediated cell death inhibition. Our data show that stimuli unrelated to interferon may trigger the upregulation of SAMHD1 and that this RF may directly interfere with IAV replication in alveolar epithelial cells.

Despite widespread use of antiretroviral therapy (ART), HIV remains a major public health issue. Even with effective ART many infected individuals still suffer from the constellation of neurological symptoms now known as neuroHIV. These symptoms can be exacerbated by substance abuse, a common comorbidity among HIV-infected individuals. The mechanism(s) by which different types of drugs impact neuroHIV remains unclear, but all drugs of abuse increase central nervous system (CNS) dopamine and elevated dopamine increases HIV infection and inflammation in human myeloid cells including macrophages and microglia, the primary targets for HIV in the brain. Thus, drug-induced increases in CNS dopamine may be a common mechanism by which distinct addictive substances alter neuroHIV. Myeloid cells are generally infected by HIV strains that use the chemokine receptor CCR5 as a co-receptor, and our data indicate that in a subset of individuals, drug-induced levels of dopamine could interfere with the effectiveness of the CCR5 inhibitor Maraviroc. CCR5 can adopt distinct conformations that differentially regulate the efficiency of HIV entry and subsequent replication and using qPCR, flow cytometry, Western blotting and high content fluorescent imaging, we show that dopamine alters the expression of specific CCR5 conformations of CCR5 on the surface of human macrophages. These changes are not affected by association with lipid rafts, but do correlate with dopamine receptor gene expression levels, specifically higher levels of D1-like dopamine receptors. These data also demonstrate that dopamine increases HIV replication and alters CCR5 conformations in human microglia similarly to macrophages. These data support the importance of dopamine in the development of neuroHIV and indicate that dopamine signaling pathways should be examined as a target in antiretroviral therapies specifically tailored to HIV-infected drug abusers. Further, these studies show the potential immunomodulatory role of dopamine, suggesting changes in this neurotransmitter may also affect the progression of other diseases.

Introduction We previously reported defective alternative polarization (M2) of macrophages and early expression of classically polarized (M1) macrophage markers in unpolarized monocyte-derived macrophages (MDMs) in patients with cystic fibrosis (CF). The present study assessed whether the mechanism(s) underlying defective macrophage polarization resided in circulating monocytes. Methods Monocyte subsets (classical, intermediate and non-classical), markers for monocyte activation (CD163) and recruitment (CD195), receptors/genes associated with macrophage differentiation and polarization were analyzed in CF and compared with healthy individuals. Results No differences were observed in the monocyte subsets or in the expression of CD163 or CD195. Expression of the M-CSF receptor, TLR4, γC, IL-4Rα, IL-13Rα1, TIMP-1 and Cox-2 were higher in CF monocytes, albeit at low levels, whereas, LRP1, MMP9, MMP28 were downregulated compared to mooncytes from healthy individuals. Conclusions Our data suggest that differences in CF monocytes may contribute to the reported CFTR-dependent defect in macrophage differentiation, polarization and function.

C-C chemokine receptor 5 (CCR5) plays an essential role in HIV pathogenesis as the major coreceptor on CD4+ T cells used by HIV, yet the function of CCR5 on CD8 T cells is not well understood. Furthermore, the immunologic effects of the CCR5 inhibitor maraviroc (MVC), despite approval for clinical use, have not yet been well evaluated for their potential effects on cytotoxic T-cell responses. In this study, we characterized the development and function of CCR5+CD8+ T cells in rhesus macaques with or without Simian immunodeficiency virus (SIV) infection. We also investigated the effects of the CCR5 antagonist MVC on functional CCR5+CD8+ T-cell responses in vitro. The data show that CCR5+CD8+ T cells have an effector memory phenotype and increase with age in systemic and mucosal lymphoid tissues as a heterogeneous population of polyfunctional CD8 T cells. In addition, CCR5 is highly expressed on SIV gag-specific (CM9+) CD8+ T cells in SIV-infected macaques, yet CCR5+CD8+ T cells are significantly reduced in mucosal lymphoid tissues with disease progression. Furthermore, in vitro MVC treatment reduced activation and cytokine secretion of CD8+ T cells via a CCR5-independent pathway. These findings suggest that surface CCR5 protein plays an important role in differentiation and activation of CD8+ T cells. Although MVC may be helpful in reducing chronic inflammation and activation, it may also inhibit virus-specific CD8+ T-cell responses. Thus optimal use of CCR5 antagonists either alone or in combination with other drugs should be defined by further investigation.-Wang, X., Russell-Lodrigue, K. E., Ratterree, M. S., Veazey, R. S., Xu, H. Chemokine receptor CCR5 correlates with functional CD8+ T cells in SIV-infected macaques and the potential effects of maraviroc on T-cell activation.

Classic Hodgkin lymphoma tumor cells express a functional CCR5 receptor, and tumor tissues express high CCL5 levels, suggesting that CCL5-CCR5 signaling is involved in tumor-microenvironment formation and tumor growth. Using the CCR5 antagonist, maraviroc, and a neutralizing anti-CCL5 antibody, we found that CCL5 secreted by classic Hodgkin lymphoma cells recruited mesenchymal stromal cells and monocytes. The “education” of mesenchymal stromal cells by tumor cell-conditioned medium enhanced mesenchymal stromal cells’ proliferation and CCL5 secretion. In turn, educated mesenchymal stromal cell-conditioned medium increased the clonogenic growth of tumor cells and monocyte migration, but these effects were reduced by maraviroc. Monocyte education by tumor cell-conditioned medium induced their growth and reprogrammed them towards immunosuppressive tumor-associated macrophages that expressed IDO and PD-L1 and secreted IL-10, CCL17 and TGF-β. Educated monocyte-conditioned medium slowed the growth of phytohemagglutinin-activated lymphocytes. Maraviroc decreased tumor cell growth and synergized with doxorubicin and brentuximab vedotin. A three-dimensional heterospheroid assay showed that maraviroc counteracted both the formation and viability of heterospheroids generated by co-cultivation of tumor cells with mesenchymal stromal cells and monocytes. In mice bearing tumor cell xenografts, maraviroc reduced tumor growth by more than 50% and inhibited monocyte accumulation, without weight loss. Finally, in classic Hodgkin lymphoma human tumor tissues, CCL5 and CD68 expression correlated positively, and patients with high CCL5 levels had poor prognosis. In conclusion, since the present challenges are to find molecules counteracting the formation of the immunosuppressive tumor microenvironment or new, less toxic drug combinations, the repurposed drug maraviroc may represent a new opportunity for classic Hodgkin lym phoma treatment.

The discovery of new chemokines that induce the migration of lymphocytes to the infection site is important for the targeted search for therapeutic agents in immunotherapy. We recently showed that Tag7 (PGLYRP1), an innate immunity protein, forms a stable complex with the Ca2+ -binding protein Mts1 (S100A4), which is able to induce lymphocyte movement, although the individual Tag7 and Mts1 do not have this activity. The purpose of this study is to identify receptors that induce the migration of lymphocytes along the concentration gradient of the Tag7-Mts1 complex, and the components of this complex capable of interacting with these receptors. The study investigated the migration of human PBMC under the action of the Tag7-Mts1complex. PBMC of healthy donors were isolated using a standard Ficoll-Hypaque gradient centrifugation procedure. It has been established that the movement of PBMC along the concentration gradient of the Tag7-Mts1 complex is induced by the classical chemotactic receptors CCR5 and CXCR3. It has been shown that only Mts1 is able to bind to the extracellular domain of CCR5, however, this binding is not enough to induce cell movement. A comparative analysis of the primary and 3D structures of the three proteins revealed the homology of the amino acid sequence fragments of the Tag7-Mts1 protein complex with different sites of the CCR5 receptor ligand - MIP1 protein. In conclusion, it should be noted that the Tag7-Mts1 complex can be considered as a new ligand of the classical chemotactic receptors CCR5 and CXCR3.

Bone metastasis is observed in up to 70% of breast cancer patients. The currently available treatment options are palliative in nature. Chemokine receptor 5 (CCR5) has gained attention as therapeutic target in various malignancies. Here, we investigated the effects of targeting CCR5 by its antagonist maraviroc in metastatic breast cancer cells. In response to maraviroc exposure, cytotoxicity was assessed using an MTT proliferation assay, whereas the effects on colony formation and migration were assessed using colony formation, transwell chamber migration and scratch wound healing assays, respectively. Apoptosis-related activities were investigated using nuclear staining, annexin-V FITC staining and Western blotting. Cell cycle changes were analysed using flow cytometry and qRT-PCR for cell cycle relevant genes. A nude rat model for breast cancer bone metastasis was used to evaluate the in vivo efficacy of CCR5 targeting by maraviroc. Circulatory levels of the three cognate ligands for CCR5 (CCL3, CCL4, CCL5) were analysed in sera of breast cancer patients using ELISA. We found that blockade of CCR5 attenuated the proliferation, colony formation and migration of metastatic breast cancer cells, and induced apoptosis and arrest in the G1 phase of the cell cycle. Expression profiling highlighted the involvement of cell cycle related signalling cascades. We also found that treatment with maraviroc significantly inhibited bone metastasis in nude rats implanted with MDA-MB-231 breast cancer cells. Finally, we found that the circulatory levels of three cognate ligands for the CCR5 receptor varied between breast cancer patients and healthy controls. Our findings indicate that targeting CCR5 may be an effective strategy to combat breast cancer bone metastasis.

The CCR5 gene is known to be responsible for inducing the inflammatory process and leukocyte chemotaxis in a wide range...

IntroductionChemokines are small transmembrane proteins with immune surveillance and immune cell recruitment functions. the expression of CCR5 gene affects virus production and viral load(1). The CCR5 gene contains two introns, three exons, and two promoters, and it is necessary as a co-receptor for the entry of the macrophage-tropic HIV strains. Mutations in the coding region of CCR5 affect the protein structure, which will affect production, chemokine binding, transport, signaling and expression of the CCR5 receptor.MethodsSNPs within CCR5 gene were retrieved from ensemble database. Coding SNPs were analyzed using SNPnexus. Coding non-synonymous SNPs in CCR5 binding domains with Viral gp120 were analyzed using SIFT, PolyPhen and I-mutant tools. Project HOPE then used to modelled the 3D structure of the protein resulting from these SNPs. Non-coding SNPs that affects miRNAs in 3’ rejoin were analyzing using PolymiRTS. SNPs that affect transcription factor binding were analyzed using regulomeDB.Results(178) non-synonyms missense SNPs were found to have deleterious and damaging effect on the structure and function of the protein. In CCR5 binding domains with Viral gp120: 3 SNPs rs145061115, rs199824195 and rs201797884 were found to affect both structure and function and stability of chemokine protein. The 2 SNPs rs185691679 and rs199722070 has a role in disruption and creation of the target sites in miRNA seeds due to their high conservation score.ConclusionMutations in CCR5 gene may explain and represent the molecular basis of the resistance to HIV infection.

Chemokine CXCR4 and CCR5 receptors are best known as HIV co-entry receptors, but evidence that CXCR4 or CCR5 blockade reduces rewarding and locomotor-stimulant effects of psychostimulants in rats suggests a role in psychostimulant use disorders. We investigated the impact of CXCR4 or CCR5 receptor antagonism on anxiety-related effects of the synthetic cathinone 3,4-methylenedioxypyrovalerone (MDPV) in the elevated zero-maze (EZM) assay. Rats exposed to a 4-day MDPV binge dosing paradigm and tested 24 or 72 h post-treatment spent more time in the open compartment at the 24-h time point but less time at the 72-h post-binge time point. Daily administration of AMD 3100, a CXCR4 antagonist (10 mg/kg), or maraviroc, a CCR5 antagonist (2.5 mg/kg), during MDPV treatment inhibited the MDPV-induced increase in time spent in the open compartment. Neither antagonist affected the MDPV-induced reduction in time spent in the open compartment at the 72-h post-binge time point. Cocaine, administered in the same paradigm as MDPV, did not increase time spent in the open compartment 24-h post-binge, suggesting specificity to MDPV. The present results identify a surprising anxiolytic-like effect of MDPV 24 h after cessation of repeated exposure that is sensitive to chemokine CXCR4 and CCR5 receptor activity.

Severe aplastic anemia (SAA) is an acquired, T cell-driven bone marrow (BM) failure disease characterized by elevated interferon gamma (IFNγ), loss of hematopoietic stem cells (HSCs), and altered BM microenvironment, including dysfunctional macrophages (MФs). T lymphocytes are therapeutic targets for treating SAA, however, the underlying mechanisms driving SAA development and how innate immune cells contribute to disease remain poorly understood. In a murine model of SAA, increased beta-chemokines correlated with disease and were partially dependent on IFNγ. IFNγ was required for increased expression of the chemokine receptor CCR5 on MФs. CCR5 antagonism in murine SAA improved survival, correlating with increased platelets and significantly increased platelet-biased CD41(hi) HSCs. T cells are key drivers of disease, however, T cell-specific CCR5 expression and T cell-derived CCL5 were not necessary for disease. CCR5 antagonism reduced BM MФs and diminished their expression of Tnf and Ccl5, correlating with reduced frequencies of IFNγ-secreting BM T cells. Mechanistically, CCR5 was intrinsically required for maintaining BM MФs during SAA. Ccr5 expression was significantly increased in MФs from aged mice and humans, relative to young counterparts. Our data identify CCR5 signaling as a key axis promoting the development of IFNγ-dependent BM failure, particularly relevant in aging where Ccr5 expression is elevated.

Background The chemokine receptor CCR5 is one of the co-receptor of HIV-1 infection. People with homozygous CCR5Δ32 deletion resist HIV-1 infection, which makes the CCR5 an important target for HIV-1 gene therapy. Although the CRISPR/Cas9 has ever been used for HIV-1 study, the newly developed CRISPR/AsCpf1 has never been utilized in HIV-1 co-receptor disruption. The CRISPR/Cpf1 system shows many advantages over CRISPR/Cas9, such as lower off-target, small size of nuclease, easy sgRNA design for multiplex gene editing, etc. Therefore, the CRISPR/Cpf1 mediated gene editing will confer a more specific and safe strategy in HIV-1 co-receptor disruption. Results Here, we demonstrated that CRISPR/AsCpf1 could ablate the main co-receptor of HIV-1 infection-CCR5 efficiently with two screened sgRNAs via different delivery strategies (lentivirus, adenovirus). The edited cells resisted R5-tropic HIV-1 infection but not X4-tropic HIV-1 infection compared with the control group in different cell types of HIV-1 study (TZM.bl, SupT1-R5, Primary CD4+T cells). Meanwhile, the edited cells exhibited selective advantage over unedited cells while under the pressure of R5-tropic HIV-1. Furthermore, we clarified that the predicted off-target sites of selected sgRNAs were very limited, which is much less than regular using sgRNAs for CRISPR/Cas9, and no evident off-target was observed. We also showed that the disruption of CCR5 by CRISPR/AsCpf1 took no effects on cell proliferation and apoptosis. Conclusions Our study provides a basis for a possible application of CCR5-targeting gene editing by CRISPR/AsCpf1 with high specific sgRNAs against HIV-1 infection.

Orchestrated trafficking and activation by pathogen-derived peptides define the ability of CD4+ T helper cells to contribute to an effective adaptive immunity. In this issue of The EMBO Journal, Martin-Leal et al show that the inflammatory chemokine receptor CCR5, well known for its role in cell migration and HIV infection, regulates ceramide synthesis and TCR nanoclustering to promote memory CD4+ T cell activation.

CCR 5 is not only a coreceptor for HIV ‐1 infection in CD 4+ T cells, but also contributes to their functional fitness. Here, we show that by limiting transcription of specific ceramide synthases, CCR 5 signaling reduces ceramide levels and thereby increases T‐cell antigen receptor (TCR ) nanoclustering in antigen‐experienced mouse and human CD 4+ T cells. This activity is CCR 5‐specific and independent of CCR 5 co‐stimulatory activity. CCR 5‐deficient mice showed reduced production of high‐affinity class‐switched antibodies, but only after antigen rechallenge, which implies an impaired memory CD 4+ T‐cell response. This study identifies a CCR 5 function in the generation of CD 4+ T‐cell memory responses and establishes an antigen‐independent mechanism that regulates TCR nanoclustering by altering specific lipid species., We thank D Sancho and JW Yewdell for rVACV‐OVA virus, RM Peregil for technical assistance, MC Moreno and S Escudero for flow cytometry services (CNB), MT Rejas and M Guerra for EM service (CBM‐SO), and C Mark for excellent editorial assistance. Fundació ACE would like to thank patients, controls, and the staff who participated in this project. This work was funded by grants from the Spanish Ministerio de Ciencia, Innovación y Universidades (SAF2017–83732‐R to SM; FIS2016‐78883‐C2‐2‐P to MC; CTQ2017‐85378‐R; AEI/FEDER, EU), the Instituto de Salud Carlos III (ISCIII) (PI13/02434, PI16/01861 to AR), the Comunidad de Madrid (B2017/BMD‐3733; IMMUNOTHERCAN‐CM to SM), and the Merck‐Salud Foundation (to SM). WWS and CD were supported by the Deutsche Forschungsgemeinschaft (DFG) through BIOSS‐EXC294 and CIBSS‐EXC 2189 (Project 390939984), SCHA976/7‐1, and SFB1381. The Genome Research @ Fundació ACE project (GR@ACE) is supported by the Fundación Bancaria La Caixa, Grifols SA, Fundació ACE, and ISCIII (Ministry of Health, Spain). Fundació ACE is a participating center in the Dementia Genetics Spanish Consortium (DEGESCO).

International audience; AbstractBackground/AimsThe chemokine CCR5 receptor is target of maraviroc, a negative allosteric modulator of CCR5 that blocks the HIV protein gp120 from associating with the receptor, thereby inhibiting virus cellular entry. As noted with other GPCR family members, the role of the lipid environment in CCR5 signaling remains obscure and very modestly investigated. Controversial literature on the impact of cholesterol depletion in HIV infection and CCR5 signaling, including the hypothesis that cholesterol depletion could inhibit HIV infection, lead us to focus on the understanding of cholesterol impact in the first stages of receptor activation.MethodsTo address this aim, the approach chosen was to employ reconstituted model lipid systems of controlled lipid composition containing CCR5 from two distinct expression systems: P. pastoris and cell‐free expression. The characterization of receptor/ligand interaction in terms of total binding or competition binding assays was independently performed by Plasmon Waveguide Resonance and Fluorescence Anisotropy, respectively. Maraviroc, a potent receptor antagonist was the ligand investigated. Additionally, Coarse‐grained Molecular Dynamics Simulation was employed to investigate cholesterol impact in the receptor conformational flexibility and dynamics.ResultsResults obtained with receptor produced by different expression systems and using different biophysical approaches clearly demonstrate a considerable impact of cholesterol in the binding affinity of maraviroc to the receptor and receptor conformational dynamics. Conclusion: Cholesterol considerably decreases maraviroc binding affinity to the CCR5 receptor. The mechanisms by which this effect occurs seems to involve the adoption of distinct receptor conformational states with restrained structural dynamics and helical motions in the presence of cholesterol.

Introduction: Human Immune Deficiency (HIV) virus is a highly mutagenic virus with diverse antigenic types and subtypes. Long latency leading to persistence in infected cell as provirus which poses great problem in developing HIV cure. The C-C Chemokine Receptor Type 5 (CCR5) molecule is a chemokine receptor, is the most important co-receptor for macrophage-tropic HIV-1 viral entry into the immune cells. In individuals with homozygous 32-bp deletion in the CCR5 gene (CCR5-del32) leads to near-complete resistance to HIV-1 infection, and also improves the prognosis in heterozygous adults with HIV-AIDS by slowing down the progression rate. Aim: Identification of CCR5 genotype in cord blood units of Indian population to generate an effective database, which may be useful as a future potential for treatment of HIV-1. Materials and Methods: This cross-sectional study for CCR5 genotyping was carried out on randomly selected Umbilical cord blood samples over a period of six months from June 2019 to November 2019 at Regrow Biosciences Private Limited, Lonavala, Pune, Maharashtra, India. Cord blood samples were screened for CCR5-del32 mutation by gene amplification using PCR based method from genomic DNA followed by agarose gel electrophoresis. All positive samples were confirmed by capillary electrophoresis. Statistical analysis was calculated using Fisher’s formula. Confidence level was determined at 95% with Confidence interval of 3.46. Results: Out of 800 samples analysed, 21 were found positive for heterozygous genotype (CCR5 ∆32/WT) that is 2.62%. None of the samples were of homozygous genotype (CCR5 ∆32/∆32). Conclusion: The CCR5- ∆32 mutation is a well-studied model of natural selection affecting humans. This mutation is known to occur in the northern Europe and western Asia with higher frequencies. The current study concludes that prevalence of heterozygous CCR5 delta 32 (∆32) mutation is extremely rare in India, also the present clinicians didn’t come across any homozygous case, yet there is need to study larger population to allow statistical comparisons.

One of the hallmarks of atherosclerosis is ongoing accumulation of macrophages in the artery intima beginning at disease onset. Monocyte recruitment contributes to increasing macrophage abundance at early stages of atherosclerosis. Although the chemokine CCL5 (RANTES) has been studied in atherosclerosis, its role in the recruitment of monocytes to early lesions has not been elucidated. We show that expression of Ccl5 mRNA, as well as other ligands of the CCR5 receptor (Ccl3 and Ccl4), is induced in the aortic intima of Ldlr−/− mice 3 weeks after the initiation of cholesterol-rich diet (CRD)-induced hypercholesterolemia. En face immunostaining revealed that CCL5 protein expression is also upregulated at 3 weeks of CRD. Blockade of CCR5 significantly reduced monocyte recruitment to 3-week lesions, suggesting that chemokine signaling through CCR5 is critical. However, we observed that Ccl5-deficiency had no effect on early lesion formation and CCL5-blockade did not affect monocyte recruitment in Ldlr−/− mice. Immunostaining of the lesions in Ldlr−/− mice and reciprocal bone marrow transplantation (BMT) of Ccl5+/+ and Ccl5−/− mice revealed that CCL5 is expressed by both myeloid and endothelial cells. BMT experiments were carried out to determine if CCL5 produced by distinct cells has functions that may be concealed in Ccl5−/−Ldlr−/− mice. We found that hematopoietic cell-derived CCL5 regulates monocyte recruitment and the abundance of intimal macrophages in 3-week lesions of Ldlr−/− mice but plays a minor role in 6-week lesions. Our findings suggest that there is a short window in early lesion formation during which myeloid cell-derived CCL5 has a critical role in monocyte recruitment and macrophage abundance.

In clinical trials, HIV-1 broadly neutralizing antibodies (bnAbs) effectively lower plasma viremia and delay virus reemergence. The presence of less neutralization-susceptible strains prior to treatment decreases the efficacy of these antibody-based treatments, but neutralization sensitivity often cannot be predicted by sequence analysis alone. We found that phenotypically confirmed CXCR4-utilizing strains are less neutralization sensitive, especially to variable loop 3 (V3 loop)-directed bnAbs, than exclusively CCR5-utilizing strains in some, but not all, cases. Homology modeling suggested that the primary V3 loop bnAb epitope is equally accessible among CCR5- and CXCR4-using strains, although variants that exclusively use CXCR4 have V3 loop protrusions that interfere with CCR5 receptor interactions. Homology modeling also showed that among some, but not all, envelopes with decreased neutralization sensitivity, V1 loop orientation interfered with V3 loop-directed bnAb binding. Thus, there are likely different structural reasons for the coreceptor usage restriction and the different bnAb susceptibilities. Importantly, we show that individuals harboring envelopes with higher likelihood of using CXCR4 or greater predicted V1 loop interference have faster virus rebound and a lower maximum decrease in plasma viremia, respectively, after treatment with a V3 loop bnAb. Knowledge of receptor usage and homology models may be useful in developing future algorithms that predict treatment efficacy with V3 loop bnAbs. IMPORTANCE The efficacy of HIV-1 broadly neutralizing antibody (bnAb) therapies may be compromised by the preexistence of less susceptible variants. Sequence-based methods are needed to predict pretreatment variants’ neutralization sensitivities. HIV-1 strains that exclusively use the CXCR4 receptor rather than the CCR5 receptor are less neutralization susceptible, especially to variable loop 3 (V3 loop) bnAbs in some, but not all, instances. While the inability to utilize the CCR5 receptor maps to a predicted protrusion in the envelope V3 loop, this viral determinant does not directly influence V3 loop bnAb sensitivity. Homology modeling predicts that contact between the envelope V1 loop and the antibody impacts V3 loop bnAb susceptibility in some cases. Among pretreatment envelopes, increased probability of using CXCR4 and greater predicted V1 interference are associated with faster virus rebound and a smaller decrease in the plasma virus level, respectively, after V3 loop bnAb treatment. Receptor usage information and homology models may be useful for predicting V3 loop bnAb therapy efficacy.

It is generally accepted that human immunodeficiency virus (HIV) is the etiological agent of acquired immune deficiency syndrome. According to this claim, HIV was transferred to humans from contact with monkeys around 35–50 years ago. However, this claim has not been sufficiently confirmed epidemiologically. The spread and incubation period of the plague epidemic has led to the theory that the Black Death was caused by hemorrhagic viruses. Having examined detailed historical data, we have concluded that the bacterium Yersenia pestis was an infectious agent in the epidemic, together with another agent which we suggest was HIV. Our considerations were mainly based on the existence of the CCR5 delta 32 mutation, which protects against HIV infection and has been present in the Caucasian population for over 2000 years. The combination of two infectious agents led to the devastation of the Black Death, the removal of HIV carriers, and an increase in the number of CCR5Δ32 mutations in the Caucasian population. In sub-Saharan Africa, this epidemic and subsequent sanitation process did not occur, which explains the much higher level of HIV genetic information in this part of the world.

Patients presenting with disproportionate hypoxia and pneumonia unresponsive to conventional antibiotics have a high index of suspicion for Pneumocystis pneumonia Pneumocystis jirovecii pneumonia is an AIDS-defining infection Placental macrophages and CD195 receptors are implicated in the pathogenesis of HIV Prompt initiation of highly active anti-retroviral therapy (HAART) therapy can resolve cryptosporidiosis infection in patients with HIV, even with no antibiotic therapy Exclusion of HIV infection is possible with antibody testing after at least 3 months of cessation of breastfeeding Evaluation of side effects of anti-retroviral therapy is necessary during follow-ups

HIV-1 acquisition occurs most commonly after sexual contact. To establish infection, HIV-1 must infect cells that support high-level replication, namely CD4+ T cells, which are absent from the outermost genital epithelium. Dendritic cells (DCs), present in mucosal epithelia, potentially facilitate HIV-1 acquisition. We show that vaginal epithelial DCs, termed CD1a+ VEDCs, are unlike other blood- and tissue-derived DCs because they express langerin but not DC-SIGN, and unlike skin-based langerin+ DC subset Langerhans cells (LCs), they do not harbor Birbeck granules. Individuals primarily acquire HIV-1 that utilizes the CCR5 receptor (termed either R5 or R5X4) during heterosexual transmission, and the mechanism for the block against variants that only use the CXCR4 receptor (classified as X4) remains unclear. We show that X4 as compared with R5 HIV-1 shows limited to no replication in CD1a+ VEDCs. This differential replication occurs after fusion, suggesting that receptor usage influences postentry steps in the virus life cycle. Furthermore, CD1a+ VEDCs isolated from HIV-1-infected virologically suppressed women harbor HIV-1 DNA. Thus, CD1a+ VEDCs are potentially infected early during heterosexual transmission and also retain virus during treatment. Understanding the interplay between HIV-1 and CD1a+ VEDCs is important for future prevention and cure strategies.

Background and aimThe hepatitis C virus (HCV) is a single-strand RNA virus that infects millions of people worldwide. Recent advances in therapy have led to viral cure using two- and three- drug combinations of direct acting inhibitors of viral replication. CCR5 is a chemokine receptor that is expressed on hepatocytes and represents a key co-receptor for HIV. We evaluated the effect of CCR5 blockade or knockdown on HCV replication in Huh7.5JFH1 cells.MethodsCells were exposed to varying concentrations of maraviroc (CCR5 inhibitor), cenicriviroc (CCR2/CCR5 inhibitor), sofosbuvir (nucleotide polymerase inhibitor), or raltegravir (HIV integrase inhibitor).ResultsHCV RNA was detected utilizing two qualitative strand-specific RT-PCR assays. HCV core antigen and NS3 protein was quantified in the supernatant and cell lysate, respectively. siRNA was utilized to knockdown CCR5 gene expression in hepatocytes. Alternatively, anti-CCR5 antibodies were employed to block the receptor. Supernatant levels of HCV RNA (expressed as fold change) were not reduced in the presence of raltegravir but were reduced 8.55-fold and 12.42-fold with cenicriviroc and maraviroc, respectively. Sofosbuvir resulted in a 16.20-fold change in HCV RNA levels. HCV core and NS3 protein production was also reduced in a dose-dependent manner. Two distinct anti-CCR5 antibodies also resulted in a significant reduction in HCV protein expression, as did siRNA knockdown of CCR5 gene expression.ConclusionsThese data provide evidence that CCR5 modulation could have a significant effect on HCV replication in an in vitro system. Further evaluation of the role of CCR5 inhibition in clinical settings may be warranted.

The chemokine receptor CCR5 is an important anti-HIV (human immunodeficiency virus) drug target owning to its pivotal role in HIV-1 viral entry as a co-receptor. Here, we present a 2.9 Å resolution crystal structure of CCR5 bound to PF-232798, a second-generation oral CCR5 antagonist currently in phase II clinical trials. PF-232798 and the marketed HIV drug maraviroc share a similar tropane scaffold with different amino (N)- and carboxyl (C)- substituents. Comparison of the CCR5–PF-232798 structure with the previously determined structure of CCR5 in complex with maraviroc reveals different binding modes of the two allosteric antagonists and subsequent conformational changes of the receptor. Our results not only offer insights into the phenomenon that PF-232798 has higher affinity and alternative resistance profile to maraviroc, but also will facilitate the design of new anti-HIV drugs.

The inflammatory chemokine CCL5, which binds the chemokine receptor CCR5 in a two-step mechanism so as to activate signaling pathways in hematopoetic cells, plays an important role in immune surveillance, inflammation, and development as well as in several immune system pathologies. The recently published crystal structure of CCR5 bound to a high-affinity variant of CCL5 lacks the N-terminal segment of the receptor that is post-translationally sulfated and is known to be important for high-affinity binding. Here, we report the NMR solution structure of monomeric CCL5 bound to a synthetic doubly sulfated peptide corresponding to the missing first 27 residues of CCR5. Our structures show that two sulfated tyrosine residues, sY10 and sY14, as well as the unsulfated Y15 form a network of strong interactions with a groove on a surface of CCL5 that is formed from evolutionarily conserved basic and hydrophobic amino acids. We then use our NMR structures, in combination with available crystal data, to create an atomic model of full-length wild-type CCR5:CCL5. Our findings reveal the structural determinants involved in the recognition of CCL5 by the CCR5 N terminus. These findings, together with existing structural data, provide a complete structural framework with which to understand the specificity of receptor:chemokine interactions. Database Structural data are available in the PDB under the accession number 6FGP.

The chemokine receptors CXCR4 (chemokine C-X-C motif receptor 4) and its ligand (stromal derived factor-1/SDF-1 or chemokinemotif ligand 12/CXCL12) play an important role in cancer invasion and metastasis. The spread of breast cancer follows a nonrandommetastatic pattern typically involving spread of tumor to regional lymph nodes, lung, liver, and/or bone marrow. The ligand for CXCR4,SDF-1/CXCL12, is highly expressed by stromal fibroblasts within these tissues. The chemokine receptors CXCR4 is structurally related tochemokine receptor belonging to the superfamily of the seven transmembrane G-protein coupled receptors. In contrast to normal breasttissue, breast cancer cells typically express high levels of functional CXCR4 receptors that can direct chemotaxis and invasive responses.Expression of SDF-1/CXCL-12 in turn, promotes the progression of breast cancer by directly enhancing tumor-cell growth and by recruitingendothelial progenitor cells that are required for tumor angiogenesis. High-level expression of CXCR4 on neoplastic cells is associated withrelatively poor overall survival and bad prognosis in patients with breast cancer. The promising results in the preclinical tumor modelsindicate that CXCR4 antagonists may have to reduce the spread of cancer that is called anti tumor activity in patients with breast cancer.The chemokine receptors CXCR4 antagonists, although initially developed for treatment of acquired immunodeficiency diseases syndrome(AIDS), actually may become effective agents as a molecular targeted therapy for breast cancer.

Chemokine receptor 5 (CCR5) plays an important role in atherosclerosis. Our objective was to develop a SPECT tracer targeting CCR5 for imaging plaque inflammation by radiolabeling D-Ala-peptide T-amide (DAPTA), a CCR5 antagonist, with 111In. 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) conjugated DAPTA (DOTA-DAPTA) was labeled with 111In. Cell uptake studies were conducted in U87-CD4-CCR5 and U87-MG cells. Biodistribution was determined in C57BL/6 mice. Autoradiography, en face and Oil Red O (ORO) imaging studies were performed in ApoE−/− mice. DOTA-DAPTA was radiolabeled with 111In with high radiochemical purity (> 98%) and specific activity (70 MBq·nmol). 111In-DOTA-DAPTA exhibited fast blood and renal clearance and high spleen uptake. The U87-CD4-CCR5 cells had significantly higher uptake in comparison to the U87-MG cells. The cell uptake was reduced by three times with DAPTA, indicating the receptor specificity of the uptake. Autoradiographic images showed significantly higher lesion uptake of 111In-DOTA-DAPTA in ApoE−/− mice than that in C57BL/6 mice. The tracer uptake in 4 month old ApoE−/− high fat diet (HFD) mice with blocking agent was twofold lower than the same mice without the blocking agent, demonstrating the specificity of the tracer for the CCR5 receptor. 111In-DOTA-DAPTA, specifically targeting chemokine receptor CCR5, is a potential SPECT agent for imaging inflammation in atherosclerosis.

Made available in DSpace on 2018-12-11T17:16:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-02-01 C–C chemokine receptor type 5 (CCR5) is a chemokine receptor that influences the immune response to infectious and parasitic diseases. This study aimed to determine whether the CCR5Δ32 and CCR5 59029 A/G polymorphisms are associated with the development of ocular toxoplasmosis in humans. Patients with positive serology for Toxoplasma gondii were analyzed and grouped as ‘with ocular toxoplasmosis’ (G1: n = 160) or ‘without ocular toxoplasmosis’ (G2: n = 160). A control group (G3) consisted of 160 individuals with negative serology. The characterization of the CCR5Δ32 and CCR5 59029 A/G polymorphisms was by PCR and by PCR-RFLP, respectively. The difference between the groups with respect to the mean age (G1: mean age: 47.3, SD ± 19.3, median: 46 [range: 18–95]; G2: mean age: 61.3, SD ± 13.7, median: 61 [range: 21–87]; G3: mean age: 38.8, SD ± 17.9, median: 34 [range: 18–80]) was statistically significant (G1 vs.G2: p-value

Familial hypercholesterolemia (FH) conveys a high risk of premature atherosclerosis as a result of lifelong exposure to high LDL cholesterol levels that are not fully reduced by standard-of-care lipid-lowering treatment. Inflammatory mediators have played a role in the progression of atherosclerotic lesions. Here, we investigated whether innate immunity cells in patients with FH have a specific proinflammatory phenotype that is distinct from that of cells in normal participants. To this end, miR-505-3p-a microRNA related to chronic inflammation-and its target genes were investigated in monocyte-derived macrophages (MACs) of patients with FH (FH-MACs) and non-FH controls (co-MACs). On the basis of the profiler PCR array analysis of agomiR-505-3p-transfected MACs, we identified the chemokine receptors, CCR3, CCR4, and CXCR1, as genes that are regulated by miR-505-3p via the transcription factor, RUNX1. miR-505-3p was significantly down-regulated, whereas CCR3, CCR4, CXCR, and RUNX1 were increased in FH-MAC compared with co-MAC, with the increase being more evident in the proinflammatory M1-like FH-MAC. Chemokine receptor levels were unrelated to LDL plasma levels at entry, but correlated with age in patients with FH, not in controls. In summary, we demonstrate for first time to our knowledge that MACs from FH-MACs have an inflammatory phenotype that is characterized by the up-regulation of CCR3, CCR4, and CXCR1 under the control of miR-505-3p. These results suggest a chronic inflammatory condition in FH innate immunity cells that is not reverted by standard lipid-lowering treatment.-Escate, R., Mata, P., Cepeda, J.M., Padró, T., Badimon, L. miR-505-3p controls chemokine receptor up-regulation in macrophages: role in familial hypercholesterolemia. FASEB J. 32, 601-612 (2018). www.fasebj.org.

Background: Cysteine-Cysteine Chemokine Receptor 5 (CCR5), also referred to as CD195, is a component of the mammalian cell membrane and is receptor for chemokines that are activated during cell damage and inflammations. This receptor is coded by a gene located in the human chromosome 3. A Mutation on this CCR5 through deletion of 32 base pairs results into a non-destructive gene CCR5Δ32. It enables protection against HIV infection to its homozygous carriers and slows progression of the disease to heterozygous carriers. Objective: To systematically review and establish global distribution of CCR5Δ32 allele in HIV-1 infected individuals over the history of the epidemic and compare regions inhabited by Caucasians, Asians and Africans. Methodology: This meta-analysis comprised of published papers with over 10,000 individuals from whom CCR5-Delta 32 allele was successfully genotyped and recorded. The study review period was from 1984 to 2017. The search targeted online sources such as Hinari specifically PubMed Central, Google scholar, Science Direct, Research4Life, National Center for Biotechnology Information (NCBI), OVID databases, AIDS Journal and Google. The searches were not limited to a particular publication language or study design but excluded letters of correspondence and conference presentations. Search strategy using key words from a combination of Medical Subject Heading (MeSH) and free text including terms related to CCR5, CCR5Δ32 and HIV were performed in Medical Literature Analysis and Retrieval System Online (MEDLINE) through Ovid Open Access. Additional studies were identified by perusing the reference list of relevant and included articles. The review considered studies conducted among general population, both HIV positive and HIV negative individuals, exposed seronegatives (ESN), exposed seropositives (ESP) and highly exposed seronegatives (HESN) and resultant data pooled using a fixed effect model. Results: A total of 40 studies comprising 10,871 participants were reviewed. These were from three main regions: Europe, Africa and Asia. Of the studies accessed and reviewed, Caucasians were 22.5%, Africans were 12.5%, Europeans were 27% and others (not specified) were 37.5%. The distribution of CCR5Δ32 allele among different populations in comparison to its heterozygosity displayed significant association with a pooled Odds Ratio (OR) of 0.08 (95% CI, 0.03 - 0.18, P < 0.00001), test of subgroup differences at I2 = 0% and a P value of 0.50. Among the Caucasians alone the OR was at 0.04 (95% CI, 0.01 - 0.19, I2 = 96%) and a significant P value of < 0.00001 displaying a high presence of CCR5Δ32 homozygosity as compared to Europeans with OR of 0.09 (95% CI, 0.04 - 0.19, I2 = 21%, P = 0.25) and Africans with OR 0.25 (95% CI, 0.03 - 2.29, I2 = 0%, P = 0.81); an indication that race can be a factor that determines CCR5Δ32 homozygosity or heterozygosity and it highly favors the Caucasians. Out of 136 homozygous carriers found in the review Europeans had 6%, Caucasian 93%, Africans 0% and others combined 0.7%. Conclusion: The distribution of CCR5Δ32, an allele that is associated with lower acquisition of HIV/AIDS is at 93% among the Caucasians. The remaining 7% is shared amongst the rest of the populations, hence high susceptibility to the disease. Minimal availability of recorded data experienced in this study is a clear indication that there exist major gaps in studies that could further associate CCR5Δ32 allele frequency and HIV infection in different populations. The review recommends a mixture of population genetics and epidemiological studies in trying to understand the increasing rates of HIV prevalence among selected groups.

Studying HIV-1 replication in the presence of functionally related proteins from different species has helped define host determinants of HIV-1 infection. Humans and owl monkeys, but not macaques, encode a CD4 receptor that permits entry of transmissible HIV-1 variants due to a single residue difference. However, little is known about whether divergent CCR5 receptor proteins act as determinants of host-range. Here we show that both owl monkey (Aotus vociferans) CD4 and CCR5 receptors are functional for the entry of transmitted HIV-1 when paired with human versions of the other receptor. By contrast, the owl monkey CD4/CCR5 pair is generally a suboptimal receptor combination, although there is virus-specific variation in infection with owl monkey receptors. Introduction of the human residues 15Y and 16T within a sulfation motif into owl monkey CCR5 resulted in a gain of function. These findings suggest there is cross-talk between CD4 and CCR5 involving the sulfation motif.

Psoriasis is a chronic inflammatory skin disease characterized by the infiltration of T cell and other immune cells to the skin in response to injury or autoantigens. Conventional, as well as unconventional, γδ T cells are recruited to the dermis and epidermis by CCL20 and other chemokines. Together with its receptor CCR6, CCL20 plays a critical role in the development of psoriasiform dermatitis in mouse models. We screened a panel of CCL20 variants designed to form dimers stabilized by intermolecular disulfide bonds. A single-atom substitution yielded a CCL20 variant (CCL20 S64C) that acted as a partial agonist for the chemokine receptor CCR6. CCL20 S64C bound CCR6 and induced intracellular calcium release, consistent with G-protein activation, but exhibited minimal chemotactic activity. Instead, CCL20 S64C inhibited CCR6-mediated T cell migration with nominal impact on other chemokine receptor signaling. When given in an IL-23-dependent mouse model for psoriasis, CCL20 S64C prevented psoriatic inflammation and the up-regulation of IL-17A and IL-22. Our results validate CCR6 as a tractable therapeutic target for psoriasis and demonstrate the value of CCL20 S64C as a lead compound.

Objective The chemokine receptor CXCR4 is highly expressed in tumor cells and plays an important role in tumor metastasis. In the present study, we report on the evaluation of a new radiopharmaceutical peptide for its potential to visualization for CXCR4-expressing tumors in vivo. Methods A CXCR4 antagonist analogue was synthesized using a standard Fmoc solid phase strategy and labeled with 99mTc via HYNIC and EDDA/tricine as coligands. In addition, stability in human serum, receptor binding internalization, in vivo tumor uptake, and tissue biodistribution were evaluated. Labeling procedure has been accomplished at 100 °C. RTLC and HPLC analysis methods have been used to confirm the procedure. The receptor binding internalization rate studied using B16-F10 melanoma tumor cells. C57BL/6 mice bearing B16-F10 tumor were used for radiopeptide biodistribution studies. Results Labeling yield of > 95% (n = 3) was obtained corresponding to a specific activity of 123 ± 60 GBq/μmol. Efficient stability in the presence of human serum was observed. The radioligand showed specific internalization (of total add) into B16-F10 cells (1.57 ± 0.27% at 2 h). In animal biodistribution study, the uptake in mouse tumor was 2.74 ± 0.47% ID/g after 15 min (percentage of injected dose per gram of tissue). Conclusion Results of this study show that labeled peptide conjugate could be a potential candidate for diagnosis of malignant tumors.

Summary Cells of hematopoietic origin can be subdivided into cells of the lymphoid lineage and those of the myeloid lineage, among which are myeloid-derived suppressor cells (MDSCs). The MDSCs can be further divided into CD11b + Ly6G − Ly6C hi monocytic (Mo) MDSCs and CD11b + Ly6G + Ly6C low polymorphonuclear (PMN) MDSCs. Both subtypes support tumor growth and suppress anti-tumor immunity. Their accumulation at the tumor site includes mobilization from the bone marrow to the blood followed by colonization at the tumor site. The present study examines the mechanism by which PMN-MDSCs are mobilized from the BM to the blood to later accumulate at the tumor site. We show that the chemokine receptor CCR5 is a key driver of this event. We also show that, beyond chemoattraction, the interaction between CCR5 and its ligands promotes the proliferation of CCR5 + PMN-MDSCs at the BM and, later, potentiates their immune-suppressive activities at the tumor site in part by inducing arginase-1.

Human immunodeficiency virus (HIV) was first reported and characterized more than three decades ago. Once thought of as a death sentence, HIV infection has become a chronically manageable disease. However, it is estimated that a staggering 0.8% of the world's population is infected with HIV, with more than 1 million deaths reported in 2015 alone. Despite the development of effective anti-retroviral drugs, a permanent cure has only been documented in one patient to date. In 2007, an HIV-positive patient received a bone marrow transplant to treat his leukemia from an individual who was homozygous for a mutation in the CCR5 gene. This mutation, known as CCR5Δ32, prevents HIV replication by inhibiting the early stage of viral entry into cells, resulting in resistance to infection from the majority of HIV isolates. More than 10 years after his last dose of anti-retroviral therapy, the transplant recipient remains free of replication-competent virus. Multiple groups are now attempting to replicate this success through the use of other CCR5-negative donor cell sources. Additionally, developments in the use of lentiviral vectors and targeted nucleases have opened the doors of precision medicine and enabled new treatment methodologies to combat HIV infection through targeted ablation or down-regulation of CCR5 expression. Here, we review historical cases of CCR5-edited cell-based therapies, current clinical trials and future benefits and challenges associated with this technology.

The chemokine receptor CCR5 has been implicated in COVID-19. CCR5 and its ligands are overexpressed in patients. The pharmacological targeting of CCR5 would improve the COVID-19 severity. We sought to investigate the role of the CCR5-Δ32 variant (rs333) in COVID-19. The CCR5-Δ32 was genotyped in 801 patients (353 in the intensive care unit, ICU) and 660 healthy controls, and the deletion was significantly less frequent in hospitalysed COVID-19 than in healthy controls (p = 0.01, OR = 0.66, 95%CI = 0.49-0.88). Of note, we did not find homozygotes among the patients, compared to 1% of the controls. The CCR5 transcript was measured in leukocytes from 85 patients and 40 controls. We found a significantly higher expression of the CCR5 transcript among the patients, with significant difference when comparing the non-deletion carriers (controls = 35; patients = 81; p = 0.01). ICU-patients showed non-significantly higher expression than no-ICU cases. Our study points to CCR5 as a genetic marker for COVID-19. The pharmacological targeting of CCR5 should be a promising treatment for COVID-19.