scholarly journals Kinetics of CXCL12 binding to atypical chemokine receptor 3 reveal a role for the receptor N terminus in chemokine binding

2019 ◽  
Vol 12 (598) ◽  
pp. eaaw3657 ◽  
Author(s):  
Martin Gustavsson ◽  
Douglas P. Dyer ◽  
Chunxia Zhao ◽  
Tracy M. Handel
Keyword(s):  
Cell Migration ◽  
G Proteins ◽  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
Scavenger Receptor ◽  
Amino Terminus ◽  
Alternative Mechanism ◽  
Globular Domain ◽  
Kinetic Measurements ◽  
Membrane Spanning

Chemokines bind to membrane-spanning chemokine receptors, which signal through G proteins and promote cell migration. However, atypical chemokine receptor 3 (ACKR3) does not appear to couple to G proteins, and instead of directly promoting cell migration, it regulates the extracellular concentration of chemokines that it shares with the G protein–coupled receptors (GPCRs) CXCR3 and CXCR4, thereby influencing the responses of these receptors. Understanding how these receptors bind their ligands is important for understanding these different processes. Here, we applied association and dissociation kinetic measurements coupled to β-arrestin recruitment assays to investigate ACKR3:chemokine interactions. Our results showed that CXCL12 binding is unusually slow and driven by the interplay between multiple binding epitopes. We also found that the amino terminus of the receptor played a key role in chemokine binding and activation by preventing chemokine dissociation. It was thought that chemokines initially bind receptors through interactions between the globular domain of the chemokine and the receptor amino terminus, which then guides the chemokine amino terminus into the transmembrane pocket of the receptor to initiate signaling. On the basis of our kinetic data, we propose an alternative mechanism in which the amino terminus of the chemokine initially forms interactions with the extracellular loops and transmembrane pocket of the receptor, which is followed by the receptor amino terminus wrapping around the core of the chemokine to prolong its residence time. These data provide insight into how ACKR3 competes and cooperates with canonical GPCRs in its function as a scavenger receptor.

scholarly journals Mycobacterium tuberculosis in Chemokine Receptor 2-Deficient Mice: Influence of Dose on Disease Progression

2002 ◽  
Vol 70 (11) ◽  
pp. 5946-5954 ◽  
Author(s):  
Holly M. Scott ◽  
JoAnne L. Flynn
Keyword(s):  
Immune Response ◽  
Mycobacterium Tuberculosis ◽  
Cell Migration ◽  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
Low Dose ◽  
High Dose ◽  
Long Term Effects ◽  
Spread Of Infection ◽  
Oxide Synthase

ABSTRACT Within a Mycobacterium tuberculosis-induced granuloma, lymphocytes and macrophages work together to control bacterial growth and limit the spread of infection. Chemokines and chemokine receptors are involved in cell migration and are logical candidates for a role in granuloma formation. In the present study we addressed the role of CC chemokine receptor 2 (CCR2) in M. tuberculosis infection. In previous studies (W. Peters et al., Proc. Natl. Acad. Sci. USA 98:7958-7963, 2001), CCR2−/− mice were found to be highly susceptible to a moderate or high dose of H37Rv administered intravenously (i.v.). We have expanded those studies to demonstrate that the susceptibility of CCR2−/− mice is dose dependent. After low-dose aerosol or i.v. infection of CCR2−/− mice with M. tuberculosis, there was a substantial delay in cell migration to the lungs and delayed expression of gamma interferon and inducible nitric oxide synthase. The CCR2−/− mice had a severe and prolonged deficiency in the number of macrophages in the lungs and an early increase in the number of neutrophils. Despite these deficiencies in cell migration, the CCR2−/− mice did not have increased bacterial loads in the lungs compared to wild-type (C57BL/6) mice and successfully formed granulomas. This finding is in contrast to CCR2−/− mice infected with a high dose of M. tuberculosis administered i.v. These results indicate that with low-dose infection, a delay in immune response in the lungs does not necessarily have detrimental long-term effects on the progression of the disease. The fact that CCR2−/− mice survive with substantially fewer macrophages in the low-dose models implies that the immune response to low-dose M. tuberculosis infection in mice is more robust than necessary to control the infection. Finally, these data demonstrate that, in cases of infectious disease in knockout models, clear phenotypes may not be evident when one is solely evaluating bacterial numbers and survival. Functional assays may be necessary to reveal roles for components of the multifactorial immune system.

scholarly journals CXCL10 Is an Agonist of the CC Family Chemokine Scavenger Receptor ACKR2/D6

Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1054
Author(s):  
Andy Chevigné ◽  
Bassam Janji ◽  
Max Meyrath ◽  
Nathan Reynders ◽  
Giulia D’Uonnolo ◽  
...  
Keyword(s):  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
Scavenger Receptor ◽  
Binding Pocket ◽  
Tumour Immunology ◽  
Dipeptidyl Peptidase 4 ◽  
Highly Sensitive ◽  
Inflammatory Chemokines ◽  
Cc Chemokines

Atypical chemokine receptors (ACKRs) are important regulators of chemokine functions. Among them, the atypical chemokine receptor ACKR2 (also known as D6) has long been considered as a scavenger of inflammatory chemokines exclusively from the CC family. In this study, by using highly sensitive β-arrestin recruitment assays based on NanoBiT and NanoBRET technologies, we identified the inflammatory CXC chemokine CXCL10 as a new strong agonist ligand for ACKR2. CXCL10 is known to play an important role in the infiltration of immune cells into the tumour bed and was previously reported to bind to CXCR3 only. We demonstrated that ACKR2 is able to internalize and reduce the availability of CXCL10 in the extracellular space. Moreover, we found that, in contrast to CC chemokines, CXCL10 activity towards ACKR2 was drastically reduced by the dipeptidyl peptidase 4 (DPP4 or CD26) N-terminal processing, pointing to a different receptor binding pocket occupancy by CC and CXC chemokines. Overall, our study sheds new light on the complexity of the chemokine network and the potential role of CXCL10 regulation by ACKR2 in many physiological and pathological processes, including tumour immunology. Our data also testify that systematic reassessment of chemokine-receptor pairing is critically needed as important interactions may remain unexplored.

scholarly journals Biased agonists of the chemokine receptor CXCR3 differentially control chemotaxis and inflammation

2018 ◽  
Vol 11 (555) ◽  
pp. eaaq1075 ◽  
Author(s):  
Jeffrey S. Smith ◽  
Lowell T. Nicholson ◽  
Jutamas Suwanpradid ◽  
Rachel A. Glenn ◽  
Nicole M. Knape ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Migration ◽  
T Cell ◽  
G Protein ◽  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
Physiological Responses ◽  
T Cell Migration ◽  
Biased Signaling ◽  
Biased Agonist

The chemokine receptor CXCR3 plays a central role in inflammation by mediating effector/memory T cell migration in various diseases; however, drugs targeting CXCR3 and other chemokine receptors are largely ineffective in treating inflammation. Chemokines, the endogenous peptide ligands of chemokine receptors, can exhibit so-called biased agonism by selectively activating either G protein– or β-arrestin–mediated signaling after receptor binding. Biased agonists might be used as more targeted therapeutics to differentially regulate physiological responses, such as immune cell migration. To test whether CXCR3-mediated physiological responses could be segregated by G protein– and β-arrestin–mediated signaling, we identified and characterized small-molecule biased agonists of the receptor. In a mouse model of T cell–mediated allergic contact hypersensitivity (CHS), topical application of a β-arrestin–biased, but not a G protein–biased, agonist potentiated inflammation. T cell recruitment was increased by the β-arrestin–biased agonist, and biopsies of patients with allergic CHS demonstrated coexpression of CXCR3 and β-arrestin in T cells. In mouse and human T cells, the β-arrestin–biased agonist was the most efficient at stimulating chemotaxis. Analysis of phosphorylated proteins in human lymphocytes showed that β-arrestin–biased signaling activated the kinase Akt, which promoted T cell migration. This study demonstrates that biased agonists of CXCR3 produce distinct physiological effects, suggesting discrete roles for different endogenous CXCR3 ligands and providing evidence that biased signaling can affect the clinical utility of drugs targeting CXCR3 and other chemokine receptors.

scholarly journals RAMP3 determines rapid recycling of atypical chemokine receptor-3 for guided angiogenesis

2019 ◽  
Vol 116 (48) ◽  
pp. 24093-24099 ◽  
Author(s):  
Duncan I. Mackie ◽  
Natalie R. Nielsen ◽  
Matthew Harris ◽  
Smriti Singh ◽  
Reema B. Davis ◽  
...  
Keyword(s):  
Cell Migration ◽  
G Protein ◽  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Directed Cell Migration ◽  
Receptor Family

Receptor-activity–modifying proteins (RAMPs) are single transmembrane-spanning proteins which serve as molecular chaperones and allosteric modulators of G-protein–coupled receptors (GPCRs) and their signaling pathways. Although RAMPs have been previously studied in the context of their effects on Family B GPCRs, the coevolution of RAMPs with many GPCR families suggests an expanded repertoire of potential interactions. Using bioluminescence resonance energy transfer-based and cell-surface expression approaches, we comprehensively screen for RAMP interactions within the chemokine receptor family and identify robust interactions between RAMPs and nearly all chemokine receptors. Most notably, we identify robust RAMP interaction with atypical chemokine receptors (ACKRs), which function to establish chemotactic gradients for directed cell migration. Specifically, RAMP3 association with atypical chemokine receptor 3 (ACKR3) diminishes adrenomedullin (AM) ligand availability without changing G-protein coupling. Instead, RAMP3 is required for the rapid recycling of ACKR3 to the plasma membrane through Rab4-positive vesicles following either AM or SDF-1/CXCL12 binding, thereby enabling formation of dynamic spatiotemporal chemotactic gradients. Consequently, genetic deletion of either ACKR3 or RAMP3 in mice abolishes directed cell migration of retinal angiogenesis. Thus, RAMP association with chemokine receptor family members represents a molecular interaction to control receptor signaling and trafficking properties.

scholarly journals Biphasic Expression of Atypical Chemokine Receptor (ACKR) 2 and ACKR4 in Colorectal Neoplasms in Association with Histopathological Findings

Biomolecules ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 8
Author(s):  
Paulina Lewandowska ◽  
Jaroslaw Wierzbicki ◽  
Marek Zawadzki ◽  
Anil Agrawal ◽  
Małgorzata Krzystek-Korpacka
Keyword(s):  
Lymph Node ◽  
Lymph Node Metastasis ◽  
Chemokine Receptor ◽  
Growth Pattern ◽  
Chemokine Receptors ◽  
Receptor Expression ◽  
Transcriptional Analysis ◽  
Neoplastic Tissue ◽  
Node Metastasis ◽  
Affected Tissue

Facilitating resolution of inflammation using atypical chemokine receptors (ACKR) as an anticancer strategy is considered but requires a deeper understanding of receptor role in carcinogenesis. We aimed at transcriptional analysis (RTqPCR) of ACKR2 and ACKR4 expression in colorectal adenoma-adenocarcinoma sequence in paired normal-neoplastic tissues from 96 polyps and 51 cancers. On average, ACKR2 was downregulated in neoplastic as compared to non-affected tissue in polyp (by 2.7-fold) and cancer (by 3.1-fold) patients. The maximal downregulation (by 8.2-fold) was observed in adenomas with the highest potential for malignancy and was gradually lessening through cancer stages I-IV, owing to increased receptor expression in tumors. On average, ACKR4 was significantly downregulated solely in adenocarcinomas (by 1.5-fold), less so in patients with lymph node metastasis, owing to a gradual decrease in ACKR4 expression among N0-N1-N2 cancers in non-affected tissue without changes in tumors. In adenomas, ACKR4 downregulation in neoplastic tissue increased with increasing potential for malignancy and contribution of villous growth pattern. ACKR4 expression increased in non-affected tissue with a concomitant decrease in pathological mucosa. In conclusion, the changes in ACKRs expression occur already in precancerous colorectal lesions, culminating in the adenomas with the highest potential for malignancy. Therefore, chemoprevention by manipulating ACKRs’ expression is worth exploration.

scholarly journals Involvement of the ERK/HIF-1α/EMT Pathway in XCL1-Induced Migration of MDA-MB-231 and SK-BR-3 Breast Cancer Cells

2020 ◽  
Vol 22 (1) ◽  
pp. 89
Author(s):  
Ha Thi Thu Do ◽  
Jungsook Cho
Keyword(s):  
Breast Cancer ◽  
Cell Migration ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Chemokine Receptor ◽  
Intracellular Signaling ◽  
Breast Cancer Cells ◽  
Epithelial Mesenchymal Transition ◽  
Mitogen Activated Protein Kinase ◽  
Mesenchymal Transition

Chemokine–receptor interactions play multiple roles in cancer progression. It was reported that the overexpression of X-C motif chemokine receptor 1 (XCR1), a specific receptor for chemokine X-C motif chemokine ligand 1 (XCL1), stimulates the migration of MDA-MB-231 triple-negative breast cancer cells. However, the exact mechanisms of this process remain to be elucidated. Our study found that XCL1 treatment markedly enhanced MDA-MB-231 cell migration. Additionally, XCL1 treatment enhanced epithelial–mesenchymal transition (EMT) of MDA-MB-231 cells via E-cadherin downregulation and upregulation of N-cadherin and vimentin as well as increases in β-catenin nucleus translocation. Furthermore, XCL1 enhanced the expression of hypoxia-inducible factor-1α (HIF-1α) and phosphorylation of extracellular signal-regulated kinase (ERK) 1/2. Notably, the effects of XCL1 on cell migration and intracellular signaling were negated by knockdown of XCR1 using siRNA, confirming XCR1-mediated actions. Treating MDA-MB-231 cells with U0126, a specific mitogen-activated protein kinase kinase (MEK) 1/2 inhibitor, blocked XCL1-induced HIF-1α accumulation and cell migration. The effect of XCL1 on cell migration was also evaluated in ER-/HER2+ SK-BR-3 cells. XCL1 also promoted cell migration, EMT induction, HIF-1α accumulation, and ERK phosphorylation in SK-BR-3 cells. While XCL1 did not exhibit any significant impact on the matrix metalloproteinase (MMP)-2 and -9 expressions in MDA-MB-231 cells, it increased the expression of these enzymes in SK-BR-3 cells. Collectively, our results demonstrate that activation of the ERK/HIF-1α/EMT pathway is involved in the XCL1-induced migration of both MDA-MB-231 and SK-BR-3 breast cancer cells. Based on our findings, the XCL1–XCR1 interaction and its associated signaling molecules may serve as specific targets for the prevention of breast cancer cell migration and metastasis.

scholarly journals Control of murine Ly6Chigh monocyte traffic and immunosuppressive activities by atypical chemokine receptor D6

Blood ◽  
2012 ◽  
Vol 119 (22) ◽  
pp. 5250-5260 ◽  
Author(s):  
Benedetta Savino ◽  
Marina G. Castor ◽  
Nicoletta Caronni ◽  
Adelaida Sarukhan ◽  
Achille Anselmo ◽  
...  
Keyword(s):  
Chemokine Receptor ◽  
Scavenger Receptor ◽  
Lymphoid Tissues ◽  
Dependent Manner ◽  
Inflammatory Reactions ◽  
Adaptive Immune ◽  
Inflammatory Conditions ◽  
Cc Chemokines ◽  
Secondary Lymphoid Organs ◽  
Selective Increase

Abstract The atypical chemokine receptor D6 is a decoy and scavenger receptor for most inflammatory CC chemokines and prevents the development of exacerbated inflammatory reactions. Here we report that mice lacking D6 expression in the nonhematopoietic compartment have a selective increase in the number of Ly6Chigh monocytes in the circulation and in secondary lymphoid tissues. Under inflammatory conditions, Ly6Chigh monocytes accumulate in increased number in secondary lymphoid organs of D6−/− mice in a CCR2-dependent manner. Ly6Chigh monocytes derived from D6−/− mice have enhanced immunosuppressive activity, inhibit the development of adaptive immune responses, and partially protect mice from the development of GVHD. Thus, control of CCR2 ligands by D6 regulates the traffic of Ly6Chigh monocytes and controls their immunosuppressive potential.

scholarly journals The Gammaherpesvirus Chemokine Binding Protein Binds to the N Terminus of CXCL8

2003 ◽  
Vol 77 (15) ◽  
pp. 8588-8592 ◽  
Author(s):  
Louise M. C. Webb ◽  
Ian Clark-Lewis ◽  
Antonio Alcami
Keyword(s):  
Receptor Binding ◽  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
Binding Protein ◽  
Sequence Similarity ◽  
Structural Requirements ◽  
Murine Gammaherpesvirus ◽  
N Terminus ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

ABSTRACT Viruses encode proteins that disrupt chemokine responses. The murine gammaherpesvirus 68 gene M3 encodes a chemokine binding protein (vCKBP-3) which has no sequence similarity to chemokine receptors but inhibits chemokine receptor binding and activity. We have used a panel of CXCL8 analogs to identify the structural requirements for CXCL8 to bind to vCKBP-3 in a scintillation proximity assay. Our data suggest that vCKBP-3 acts by mimicking the binding of chemokine receptors to CXCL8.

scholarly journals A V3 Loop-Dependent gp120 Element Disrupted by CD4 Binding Stabilizes the Human Immunodeficiency Virus Envelope Glycoprotein Trimer

2010 ◽  
Vol 84 (7) ◽  
pp. 3147-3161 ◽  
Author(s):  
Shi-Hua Xiang ◽  
Andrés Finzi ◽  
Beatriz Pacheco ◽  
Kevin Alexander ◽  
Wen Yuan ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Receptor Binding ◽  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
Envelope Glycoproteins ◽  
V3 Loop ◽  
Virus Envelope ◽  
Hydrophobic Patch ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus (HIV-1) entry into cells is mediated by a trimeric complex consisting of noncovalently associated gp120 (exterior) and gp41 (transmembrane) envelope glycoproteins. The binding of gp120 to receptors on the target cell alters the gp120-gp41 relationship and activates the membrane-fusing capacity of gp41. Interaction of gp120 with the primary receptor, CD4, results in the exposure of the gp120 third variable (V3) loop, which contributes to binding the CCR5 or CXCR4 chemokine receptors. We show here that insertions in the V3 stem or polar substitutions in a conserved hydrophobic patch near the V3 tip result in decreased gp120-gp41 association (in the unliganded state) and decreased chemokine receptor binding (in the CD4-bound state). Subunit association and syncytium-forming ability of the envelope glycoproteins from primary HIV-1 isolates were disrupted more by V3 changes than those of laboratory-adapted HIV-1 envelope glycoproteins. Changes in the gp120 β2, β19, β20, and β21 strands, which evidence suggests are proximal to the V3 loop in unliganded gp120, also resulted in decreased gp120-gp41 association. Thus, a gp120 element composed of the V3 loop and adjacent beta strands contributes to quaternary interactions that stabilize the unliganded trimer. CD4 binding dismantles this element, altering the gp120-gp41 relationship and rendering the hydrophobic patch in the V3 tip available for chemokine receptor binding.

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