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

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.

Blood ◽  
2011 ◽  
Vol 118 (7) ◽  
pp. 1818-1827 ◽  
Author(s):  
Thomas Quast ◽  
Felix Eppler ◽  
Verena Semmling ◽  
Cora Schild ◽  
Yahya Homsi ◽  
...  

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.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 650.2-651
Author(s):  
P. C. Taylor ◽  
E. Elboudwarej ◽  
B. Downie ◽  
J. Liu ◽  
R. E. Hawtin ◽  
...  

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.


Rheumatology ◽  
2020 ◽  
Vol 59 (Supplement_2) ◽  
Author(s):  
Peter C Taylor ◽  
Emon Elboudwarej ◽  
Wanying Li ◽  
Rachael E Hawtin ◽  
Jinfeng Liu ◽  
...  

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.


1996 ◽  
Vol 59 (5) ◽  
pp. 443-452 ◽  
Author(s):  
Sanae ICHIKAWA ◽  
Yasuhide GOTO ◽  
Shigeo UCHINO ◽  
H. Benfer KALTREIDER ◽  
Edward J. GOETZL ◽  
...  

2010 ◽  
Vol 2010 ◽  
pp. 1-13 ◽  
Author(s):  
Fei Xue ◽  
Deanna M. Janzen ◽  
David A. Knecht

Numerous F-actin containing structures are involved in regulating protrusion of membrane at the leading edge of motile cells. We have investigated the structure and dynamics of filopodia as they relate to events at the leading edge and the function of the trailing actin networks. We have found that although filopodia contain parallel bundles of actin, they contain a surprisingly nonuniform spatial and temporal distribution of actin binding proteins. Along the length of the actin filaments in a single filopodium, the most distal portion contains primarily T-plastin, while the proximal portion is primarily bound byα-actinin and coronin. Some filopodia are stationary, but lateral filopodia move with respect to the leading edge. They appear to form a mechanical link between the actin polymerization network at the front of the cell and the myosin motor activity in the cell body. The direction of lateral filopodial movement is associated with the direction of cell migration. When lateral filopodia initiate from and move toward only one side of a cell, the cell will turn opposite to the direction of filopodial flow. Therefore, this filopodia-myosin II system allows actin polymerization driven protrusion forces and myosin II mediated contractile force to be mechanically coordinated.


2019 ◽  
Author(s):  
Inge M. N. Wortel ◽  
Katharina Dannenberg ◽  
Jeffrey C. Berry ◽  
Mark J. Miller ◽  
Johannes Textor

AbstractSummaryVisualization of cell migration via time-lapse microscopy has greatly advanced our understanding of the immune system. However, subtle differences in migration dynamics are easily obscured by biases and imaging artifacts. While several analysis methods have been suggested to address these issues, an integrated tool implementing them is currently lacking. Here, we present CelltrackR, an R package containing a diverse set of state-of-the-art analysis methods for (immune) cell tracks. CelltrackR supports the complete pipeline for track analysis by providing methods for data management, quality control, extracting and visualizing migration statistics, clustering tracks, and simulating cell migration.Availability and ImplementationCelltrackR is an open-source package released under the GPL-2 license, and is freely available on GitHub at https://github.com/ingewortel/[email protected], [email protected]


2009 ◽  
Vol 136 (5) ◽  
pp. A-424-A-425
Author(s):  
Xiaofang Huo ◽  
Hui Ying Zhang ◽  
Xi Zhang ◽  
Kathy Hormi-Carver ◽  
Stuart J. Spechler ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document