CD81 is essential for the formation of membrane protrusions and regulates Rac1-activation in adhesion-dependent immune cell migration

Blood ◽  
2011 ◽  
Vol 118 (7) ◽  
pp. 1818-1827 ◽  
Author(s):  
Thomas Quast ◽  
Felix Eppler ◽  
Verena Semmling ◽  
Cora Schild ◽  
Yahya Homsi ◽  
...  
Keyword(s):  
Total Internal Reflection ◽  
Immune Cell ◽  
Virus Entry ◽  
Basal Layer ◽  
Leading Edge ◽  
Surface Receptors ◽  
Rac1 Activity ◽  
Membrane Protrusions ◽  
Immune Cell Migration ◽  
Actin Protrusions

Abstract CD81 (TAPA-1) is a member of the widely expressed and evolutionary conserved tetraspanin family that forms complexes with a variety of other cell surface receptors and facilitates hepatitis C virus entry. Here, we show that CD81 is specifically required for the formation of lamellipodia in migrating dendritic cells (DCs). Mouse CD81−/− DCs, or murine and human CD81 RNA interference knockdown DCs lacked the ability to form actin protrusions, thereby impairing their motility dramatically. Moreover, we observed a selective loss of Rac1 activity in the absence of CD81, the latter of which is exclusively required for integrin-dependent migration on 2-dimensional substrates. Neither integrin affinity for substrate nor the size of basal integrin clusters was affected by CD81 deficiency in adherent DCs. However, the use of total internal reflection fluorescence microscopy revealed an accumulation of integrin clusters above the basal layer in CD81 knockdown cells. Furthermore, β1- or β2-integrins, actin, and Rac are strongly colocalized at the leading edge of DCs, but the very fronts of these cells protrude CD81-containing membranes that project outward from the actin–integrin area. Taken together, these data suggest a thus far unappreciated role for CD81 in the mobilization of preformed integrin clusters into the leading edge of migratory DCs on 2-dimensional surfaces.

scholarly journals Subcellular optogenetic activation of Cdc42 controls local and distal signaling to drive immune cell migration

2016 ◽  
Vol 27 (9) ◽  
pp. 1442-1450 ◽  
Author(s):  
Patrick R. O’Neill ◽  
Vani Kalyanaraman ◽  
N. Gautam
Keyword(s):  
Cell Migration ◽  
Intracellular Signaling ◽  
Immune Cell ◽  
Leading Edge ◽  
Signaling Networks ◽  
Membrane Protrusions ◽  
A Cell ◽  
Immune Cell Migration ◽  
Directional Cell Migration ◽  
Rhoa Signaling

Migratory immune cells use intracellular signaling networks to generate and orient spatially polarized responses to extracellular cues. The monomeric G protein Cdc42 is believed to play an important role in controlling the polarized responses, but it has been difficult to determine directly the consequences of localized Cdc42 activation within an immune cell. Here we used subcellular optogenetics to determine how Cdc42 activation at one side of a cell affects both cell behavior and dynamic molecular responses throughout the cell. We found that localized Cdc42 activation is sufficient to generate polarized signaling and directional cell migration. The optically activated region becomes the leading edge of the cell, with Cdc42 activating Rac and generating membrane protrusions driven by the actin cytoskeleton. Cdc42 also exerts long-range effects that cause myosin accumulation at the opposite side of the cell and actomyosin-mediated retraction of the cell rear. This process requires the RhoA-activated kinase ROCK, suggesting that Cdc42 activation at one side of a cell triggers increased RhoA signaling at the opposite side. Our results demonstrate how dynamic, subcellular perturbation of an individual signaling protein can help to determine its role in controlling polarized cellular responses.

Rho GTPase Cdc42 Maintains Neutrophil Polarity during Directed Migration by Regulating CD11b Integrin Signals.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 238-238
Author(s):  
Kathleen Szczur ◽  
Yi Zheng ◽  
Marie-Dominique Filippi
Keyword(s):  
Cell Polarity ◽  
Rho Gtpase ◽  
Critical Role ◽  
Leading Edge ◽  
Negative Regulator ◽  
Blocking Antibody ◽  
Directed Migration ◽  
Cellular Defense ◽  
Membrane Protrusions ◽  
Actin Protrusions

Abstract Neutrophil (PMN) migration to sites of infection is the first line of cellular defense. Among others, a key event of cell migration is the maintenance of a polarized morphology characterized by a single protrusive leading edge of F-actin and a contractile uropod devoid of F-actin protrusions. Using mice genetically deficient in the Cdc42 negative regulator Cdc42 GTPase Activating Protein, we previously demonstrated that Cdc42 activity suppresses membrane protrusions at the uropod of the cells to maintain stable polarity during directed migration (Szczur et al, Blood 2006). However, the underlying molecular mechanism of Cdc42-mediated neutrophil polarity remains to be understood. Here, using mice with a conditional Cdc42 (flox) allele, we showed by video microscopy that Cdc42−/− PMNs exhibited multiple membrane extensions in various directions and failed to maintain cell polarity and directionality towards formyl-methionyl-leucyl-phenylalanin (fMLP) gradient compared to wild type (WT) cells. Consistent with this observation, Cdc42−/− PMNs exhibited increased lamellipodia protrusions of F-actin all around the cells compared to WT PMNs, in response to fMLP stimulation and fibrinogen ligation, confirming that Cdc42 maintains stable polarity by preventing abnormal membrane protrusions outside the leading edge. To understand how Cdc42 orchestrates neutrophil polarity at a mechanistic level, we explored the possibility of a role for integrins in this process since Cdc42 appears to regulate neutrophil polarity in a manner, at least in part, dependent on integrin ligation (Szczur et al, Blood 2006). Expression of the neutrophil integrin, CD11b/CD18, on resting or fMLP-stimulated PMNs was similar between the genotypes. Stimulation of WT PMNs with fMLP and ligation to fibrinogen induced a polarized distribution of CD11b into clusters mostly concentrated at the uropod of the cells. Remarkably, the numbers of CD11b clusters of Cdc42−/− PMNs were significantly decreased compared to WT cells. Furthermore, inhibition of CD11b clustering in WT PMNs, using anti-CD11b blocking antibody, significantly increased membrane protrusions associated with loss of stable polarity during directed migration, similarly to Cdc42-deficiency. Enforcing CD11b clustering by CD11b cross-linking in Cdc42−/− PMNs partially rescued cell polarity and F-actin distribution concentrated only at the leading edge of the cells to WT levels. These results strongly suggest that CD11b clustering is regulated by Cdc42 activity and contributes to suppress F-actin protrusions at the uropod of neutrophils during migration. The uropod distribution of CD11b suggests that CD11b may recruit contractile proteins, such as the myosin regulator myosin light chain (MLC), to antagonize membrane protrusions. To test this hypothesis, we analyzed the distribution of phosphorylated MLC (p-MLC). Upon stimulation, p-MLC strongly translocated to the uropod of WT cells. In contrast, p-MLC remained diffuse and non polarized in the cytoplasm of Cdc42−/− cells. Blocking CD11b function in WT cells abrogated the polarized distribution of p-MLC mimicking Cdc42−/− PMNs. Enforcing CD11b clustering in Cdc42−/− PMNs rescued p-MLC signals concentrated at the uropod of the cells. Altogether, this study suggests that Cdc42 activity maintains neutrophil polarity during directed migration by regulating CD11b clustering/distribution and subsequent outside/in signals to suppress lateral membrane protrusions. This study uncovers a critical role for CD11b in maintaining neutrophil polarity during migration.

scholarly journals The G Protein-Coupled Receptor Kinases (GRKs) in Chemokine Receptor-Mediated Immune Cell Migration: From Molecular Cues to Physiopathology

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 75
Author(s):  
Marta Laganà ◽  
Géraldine Schlecht-Louf ◽  
Françoise Bachelerie
Keyword(s):  
G Protein ◽  
Chemokine Receptor ◽  
Immune Cell ◽  
Neutrophil Migration ◽  
G Protein Coupled Receptor ◽  
Receptor Kinases ◽  
Immune Cell Migration ◽  
And Migration ◽  
G Protein Coupled ◽  
Gpcr Desensitization

Although G protein-coupled receptor kinases (GRKs) have long been known to regulate G protein-coupled receptor (GPCR) desensitization, their more recently characterized functions as scaffolds and signalling adapters underscore that this small family of proteins governs a larger array of physiological functions than originally suspected. This review explores how GRKs contribute to the complex signalling networks involved in the migration of immune cells along chemokine gradients sensed by cell surface GPCRs. We outline emerging evidence indicating that the coordinated docking of several GRKs on an active chemokine receptor determines a specific receptor phosphorylation barcode that will translate into distinct signalling and migration outcomes. The guidance cues for neutrophil migration are emphasized based on several alterations affecting GRKs or GPCRs reported to be involved in pathological conditions.

scholarly journals FRI0136 PERIPHERAL PROTEIN BIOMARKER CHANGES FOLLOWING SELECTIVE INHIBITION OF JANUS KINASE 1 (JAK1) BY FILGOTINIB IN ADULTS WITH MODERATELY-TO-SEVERELY ACTIVE RHEUMATOID ARTHRITIS WITH PRIOR INADEQUATE RESPONSE TO METHOTREXATE (FINCH1)

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 650.2-651
Author(s):  
P. C. Taylor ◽  
E. Elboudwarej ◽  
B. Downie ◽  
J. Liu ◽  
R. E. Hawtin ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Cell Migration ◽  
Active Rheumatoid Arthritis ◽  
Immune Cell ◽  
Janus Kinase ◽  
Inadequate Response ◽  
Bone Biology ◽  
Janus Kinase 1 ◽  
Immune Cell Migration ◽  
Dose Dependent

Background:Filgotinib (FIL), an oral selective Janus kinase 1 (JAK1) inhibitor has shown efficacy and safety in multiple phase 3 studies in adults with moderately-to-severely active rheumatoid arthritis (RA), including those with prior inadequate response to methotrexate (MTX) therapy (FINCH1;NCT02889796).Objectives:A longitudinal study of protein biomarkers related to JAK signaling1, bone biology2, immune cell migration2, and inflammation2was conducted to identify RA-associated markers altered by FIL vs MTX or adalimumab (ADA).Methods:FINCH1 RA patients (pts) were randomized to receive either a stable dose of MTX with placebo (PBO+MTX), ADA+MTX, and either FIL100mg+MTX or FIL200mg+MTX, once daily. Plasma, serum, and urine samples were taken from a subset of pts (~548) at baseline (BL) and weeks (wks) 4 and 12. Twenty-six pre-defined cytokines (biomarkers) were evaluated using ELISA. BL correlation between biomarkers and clinical response measures (DAS28CRP, SJC28, TJC28, CDAI, Patient Assessment and FACIT), were analyzed by Spearman Rank. Multiscale bootstrap resampling evaluated significant intra-cluster biomarker membership. Mean changes in biomarker levels from BL to wks 4 and 12 were compared between arms using PBO-adjusted estimates from a linear mixed effects model. A 5% false-discovery rate was applied for all analyses.Results:At BL, distinct biomarker-based pt clusters (CL) were identified. The strongest intra-group correlations were in bone-cartilage resorption/inflammation (CL1; Rho range 0.37–0.88) and JAK activity (CL2; Rho range 0.41–0.71). Individual BL cytokine levels were significantly associated with DAS28CRP, with unique biomarkers specific to various subcomponents of the score. Eleven biomarkers were associated with DAS28CRP, while 5, 3, and 2 were associated with CDAI, SJC28, and TJC28, respectively. The magnitude of FIL-associated treatment effects was time- and dose-dependent. Significant biomarker changes from BL were observed in FIL pts, relative to PBO+MTX pts. FIL100mg+MTX led to a significant change in 8 biomarkers by either 4 or 12 wks of treatment; FIL200mg+MTX significantly changed these and an additional 4 biomarkers by either time point. The greatest effect of FIL200mg+MTX was at 12 wks for CXCL13 (-38.4%) and IL6 (-53.7%). All treatment arms led to significant reductions in TNFα relative to PBO+MTX. FIL200mg+MTX treatment led to larger reductions of TNFα than ADA+MTX treatment at both wk4 (-24.7% vs -17.9%) and wk12 (-20.5% vs -12.2%), although the differences were not statistically significant.FIL and ADA caused differential patterns of cytokine response at either wks 4 or 12. Of 12 biomarkers with a significant FIL200mg+MTX treatment effect, there was a significantly larger reduction in TNFSF13B and CTX1 relative to ADA+MTX at 12 wks. Of 8 biomarkers with FIL100mg+MTX effects, only 2 (CXCL10 at wk 4; CXCL13 at wks 4 and 12) had significant differences from ADA+MTX. Relative either to FIL200mg+MTX or FIL100mg+MTX, and despite the same direction of effect, ADA+MTX led to a significantly larger reduction in CCL2, CXCL10, CCL4, and CXCL13.Conclusion:Compared with PBO, 12 wks of FIL treatment significantly reduced cytokines associated with JAK activity1, bone biology2, inflammation2, and immune cell migration2in MTX-IR pts. The effects were largely FIL dose-dependent; most cytokines exhibited similar effects regardless of treatment arms, but differential changes between FIL+MTX and ADA+MTX were observed, supportive of the different mechanisms of action of these therapies.References:[1]Majoros A, et al. Front Immunol. 2017;8:29[2]Brennan F, and McInnes I. J Clin Invest. 2008;118:3537-45Acknowledgments:This study was funded by Gilead Sciences, Inc. Editorial support was provided by Fishawack Communications Inc and funded by Gilead Sciences, Inc.Disclosure of Interests:Peter C. Taylor Grant/research support from: Celgene, Eli Lilly and Company, Galapagos, and Gilead, Consultant of: AbbVie, Biogen, Eli Lilly and Company, Fresenius, Galapagos, Gilead, GlaxoSmithKline, Janssen, Nordic Pharma, Pfizer Roche, and UCB, Emon Elboudwarej Shareholder of: Gilead Sciences Inc., Employee of: Gilead Sciences Inc., Bryan Downie Shareholder of: Gilead Sciences Inc., Employee of: Gilead Sciences Inc., Jinfeng Liu Shareholder of: Gilead Sciences Inc., Roche, Employee of: Gilead Sciences Inc., Rachael E. Hawtin Shareholder of: Gilead Sciences Inc., Employee of: Gilead Sciences Inc., Amer M. Mirza Shareholder of: Gilead Sciences Inc., Employee of: Gilead Sciences Inc.

scholarly journals P215 Filgotinib, a janus kinase 1 selective inhibitor, modulates disease-associated cytokines in patients with active RA

Rheumatology ◽  
2020 ◽  
Vol 59 (Supplement_2) ◽  
Author(s):  
Peter C Taylor ◽  
Emon Elboudwarej ◽  
Wanying Li ◽  
Rachael E Hawtin ◽  
Jinfeng Liu ◽  
...  
Keyword(s):  
Cell Migration ◽  
Disease Activity ◽  
Clinical Response ◽  
Immune Cell ◽  
Selective Inhibitor ◽  
Janus Kinase ◽  
Stock Ownership ◽  
Inadequate Response ◽  
Bone Biology ◽  
Immune Cell Migration

Abstract Background Filgotinib (FIL), an oral JAK1-selective inhibitor, was safe and effective in FINCH2, a randomised, double-blind, placebo (PBO)-controlled, phase 3 study in patients with active rheumatoid arthritis (RA) who had an inadequate response to methotrexate (MTX) and ≥1 biologic disease-modifying antirheumatic drug. A longitudinal study of cytokines from patients in FINCH2 was conducted to identify RA-associated biomarkers related to bone biology, immune cell migration, and inflammation that are altered by FIL therapy; and FIL-associated biomarkers that correlate with clinical response (DAS28CRP, swollen and tender joint counts, pain, and fatigue). Methods Plasma, serum and urine samples from RA patients (n = 449) receiving FIL (100mg, 200mg) or PBO once daily plus MTX were analysed at baseline (BL) and week 12 (W12) for 42 disease-relevant cytokines using validated, commercially available single- or multiplex assays. PBO corrected on-treatment changes in cytokine levels from BL to W12 were compared between treatment arms (Wilcoxon rank sum). Spearman rank correlation was used to compare changes in cytokine level from BL to W12 and clinical response. P-values <0.05 were considered significant. Results At W12, 18 of 42 cytokines significantly decreased with FIL 100mg treatment relative to PBO; FIL 200mg decreased these cytokines to a similar or greater degree. An additional 6 cytokines were significantly decreased by FIL 200mg. Conversely, 2 cytokines increased relative to PBO with FIL 100mg, and 6 cytokines increased with FIL 200mg (sIL-6R, IL10, GMCSF, IL2, leptin, and IL17A). Biomarkers most significantly modulated by FIL 200mg (p < 0.0001) included markers related to bone biology (MMP1 [-22.8%], MMP3 [-24.7%], CTX1 [-27.4% ], and NTX [-16.4%]), immune cell migration (VCAM1 [-20.0%], ICAM1 [-14.2%], CXCL13 [-45.0%], and CXCL10 [-32.3%]), and inflammation (TNFRI[-20.7%], CRP [-77.4%], SAA [-61.8%], and resistin [-20.2%]). Hierarchical clustering of BL biomarker levels revealed distinct groups of cytokines that were strongly correlated with each other. Among them, SAA, IL6 and CXCL10, were significantly positively correlated with each other (rho>0.6) and with RA disease activity (DAS28CRP) at BL (rho>0.3). Biomarkers, including CRP (IL6, SAA), PainVAS (CRP, SAA), and SJC28 (CRP, IL6, CXCL10), were also significantly correlated with individual components of DAS28CRP. Several biomarkers associated with RA disease activity at BL were decreased with FIL at W12 relative to PBO (FIL 100mg: CRP [-48.7%], SAA [-36.9%], and IL6 [-2.6%] and FIL 200mg: CRP [-77.4%], SAA [-61.8%], IL6 [-13.6%], CXCL10 [-32.3%]), suggesting FIL impacts these disease activities at a molecular level. Conclusion Twelve weeks of FIL treatment significantly reduced 24 disease-relevant cytokines in patients with active RA. Effects were dose-dependent and suggest a shift toward restored immune homeostasis. Findings are consistent with the clinical efficacy of FIL in FINCH2. Disclosures P.C. Taylor: Consultancies; Consultant for AbbVie, BMS, Jansses, Pfizer, Roche, Lilly, Sanofi, MSD, Novartis, Celgene and Gilead. E. Elboudwarej: Corporate appointments; Employee of Gilead Sciences, Inc. Shareholder/stock ownership; Shareholder of Gilead Sciences, Inc. W. Li: Corporate appointments; Employee of Gilead Sciences, Inc. Shareholder/stock ownership; Shareholder of Gilead Sciences, Inc. R.E. Hawtin: Corporate appointments; Employee of Gilead Sciences, Inc. Shareholder/stock ownership; Shareholder of Gilead Sciences, Inc. J. Liu: Corporate appointments; Employee of Gilead Sciences, Inc. Shareholder/stock ownership; Shareholder of Gilead Sciences, Inc. A.M. Mirza: Corporate appointments; Employee of Gilead Sciences, Inc. Shareholder/stock ownership; Shareholder of Gilead Sciences, Inc.

scholarly journals Changes in Adhesion Molecule Expression During Distinct Patterns of Immune Cell Migration in the Inflamed Lung.

1996 ◽  
Vol 59 (5) ◽  
pp. 443-452 ◽  
Author(s):  
Sanae ICHIKAWA ◽  
Yasuhide GOTO ◽  
Shigeo UCHINO ◽  
H. Benfer KALTREIDER ◽  
Edward J. GOETZL ◽  
...  
Keyword(s):  
Cell Migration ◽  
Adhesion Molecule ◽  
Immune Cell ◽  
Adhesion Molecule Expression ◽  
Immune Cell Migration

scholarly journals Endothelial junctional membrane protrusions serve as hotspots for neutrophil transmigration

2021 ◽  
Author(s):  
Janine J.G. Arts ◽  
Eike K. Mahlandt ◽  
Max L.B. Grönloh ◽  
Lilian Schimmel ◽  
Ivar Noordstra ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Light Sheet ◽  
Cell Junctions ◽  
Light Sheet Microscopy ◽  
Rac1 Activity ◽  
Membrane Protrusions ◽  
Vessel Walls ◽  
Inflamed Tissue

AbstractUpon inflammation, leukocytes rapidly transmigrate across the endothelium to enter the inflamed tissue. Evidence accumulates that leukocytes use preferred exit sites, though it is not yet clear how these hotspots in the endothelium are defined and how they are recognized by the leukocyte. Using lattice light sheet microscopy, we discovered that leukocytes prefer endothelial membrane protrusions at cell junctions for transmigration. Phenotypically, these junctional membrane protrusions are present in an asymmetric manner, meaning that one endothelial cell shows the protrusion and the adjacent one does not. Consequently, leukocytes cross the junction by migrating underneath the protruding endothelial cell. These protrusions depend on Rac1 activity and by using a photo-activatable Rac1 probe, we could artificially generate local exit-sites for leukocytes. Overall, we have discovered a new mechanism that uses local induced junctional membrane protrusions to facilitate/steer the leukocyte escape/exit from inflamed vessel walls.

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