scholarly journals Shear flow-driven actin re-organization induces ICAM-1 nanoclustering on endothelial cells that impact T-cell migration

2020 ◽  
Author(s):  
Izabela K. Piechocka ◽  
Sarah Keary ◽  
Alberto Sosa-Costa ◽  
Lukas Lau ◽  
Nitin Mohan ◽  
...  

ABSTRACTThe leukocyte specific β2-integrin LFA-1, and its ligand ICAM-1 expressed on endothelial cells (ECs), are involved in the arrest, adhesion and transendothelial migration of leukocytes. Although the role of mechanical forces on LFA-1 activation is well established, the impact of forces on its major ligand ICAM-1, has received less attention. Using a parallel-plate flow chamber combined with confocal and super-resolution microscopy, we show that prolonged shear-flow induces a global translocation of ICAM-1 on ECs upstream of flow direction. Interestingly, shear-forces promoted ICAM-1 nanoclustering prior to LFA-1 engagement. This spatial nanoscale organization was driven by actin cytoskeleton re-arrangements induced by shear-force. We further assessed the impact of prolonged shear-stress EC stimulation on T cell migration. T cells adhered to mechanically pre-stimulated ECs developed a more pro-migratory phenotype, migrated faster and exhibited shorter EC interactions than when adhered to non-mechanically stimulated ECs. Together, our results indicate that shear-forces increase the number of ICAM-1/LFA-1 bonds due to ICAM-1 nanoclustering, strengthening adhesion and thereby reducing actin retrograde flow of T-cells, leading to their increased migration speed. Our data also underscores the importance of mechanical forces regulating the spatial organization of cell membrane receptors and their contribution to adhesion regulation, regardless of integrin activation.Summary statementWe show that shear forces promote ICAM-1 spatial re-arrangement and actin-dependent nanoclustering on ECs prior to integrin engagement. This mechanism might be important for firm leukocyte adhesion and migration during the immune response.

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Melissa A Lopes Pinheiro ◽  
Alwin Kamermans ◽  
Juan J Garcia-Vallejo ◽  
Bert van het Hof ◽  
Laura Wierts ◽  
...  

Trafficking of myelin-reactive CD4+ T-cells across the brain endothelium, an essential step in the pathogenesis of multiple sclerosis (MS), is suggested to be an antigen-specific process, yet which cells provide this signal is unknown. Here we provide direct evidence that under inflammatory conditions, brain endothelial cells (BECs) stimulate the migration of myelin-reactive CD4+ T-cells by acting as non-professional antigen presenting cells through the processing and presentation of myelin-derived antigens in MHC-II. Inflamed BECs internalized myelin, which was routed to endo-lysosomal compartment for processing in a time-dependent manner. Moreover, myelin/MHC-II complexes on inflamed BECs stimulated the trans-endothelial migration of myelin-reactive Th1 and Th17 2D2 cells, while control antigen loaded BECs did not stimulate T-cell migration. Furthermore, blocking the interaction between myelin/MHC-II complexes and myelin-reactive T-cells prevented T-cell transmigration. These results demonstrate that endothelial cells derived from the brain are capable of enhancing antigen-specific T cell recruitment.


Rheumatology ◽  
2020 ◽  
Vol 59 (Supplement_2) ◽  
Author(s):  
Emma Garcia-Melchor ◽  
Giacomo Cafaro ◽  
Shatakshi Sood ◽  
Lindsay A. N Crowe ◽  
Michael McLean ◽  
...  

Abstract Background Mechanical stress or damage is a well-known inducer of inflammation in both psoriasis and psoriatic arthritis (PsA). The occurrence of microtrauma at enthesial sites, areas subjected to high mechanic stress, could explain the development of local inflammation (enthesitis) that further extends to the synovial tissue through what it is known synovio-entheseal complex. Current treatment strategies mainly target the immune compartment, however there is growing evidence for the role of the stroma in the development of chronic inflammation. Increasing attention has focused on the interaction between the stroma and immune system and its role in the initiation/development of tissue inflammatory chronicity. Our hypothesis is that stromal cells in the tendon or tenocytes, once activated, are able to recruit and activate T cells into the tendon, which in turn may have an effect on the stroma, altogether leading to chronicity. Methods We assessed the effect of damage on healthy tenocytes after stimulation with conditioned media from tendon explants or IL-1β by qPCR and ELISA. A transwell membrane system was used to test the impact of conditioned media from tenocytes on T cell migration. T cells and tenocytes were co-cultured with or without the presence of a transwell membrane to quantify T cell activation (CD69 by FACS and IFN-γ by ELISA). Changes in gene expression on tenocytes after co-culture with activated T cells were analysed by qPCR. Results In the presence of damage, tenocytes upregulated inflammatory cytokines (IL-1β, IL-6), chemokines (IL-8, CCL2, CCL5, CXCL10) and adhesion molecules (ICAM-1). Of interest, we observed an upregulation of CCL20, both at transcript and protein level. Conditioned media from tenocytes induced T cell migration, especially after stimulation. Co-culture of tenocytes and T cells resulted in contact dependant activation of T cells. These activated T cells also had an effect on tenocytes, further upregulating the production of inflammatory mediators. Conclusion These results support the role of the tendon stromal compartment in the recruitment and activation of T cells, creating a feedback loop that could be involved in the maintenance of the inflammatory process and the development of chronicity in the context of PsA. Moreover, the production of CCL20 by tenocytes after damage could explain the preferential recruitment of Th17 or gamma delta T cells into the tendon. We are further investigating the mechanisms that govern this relationship that could be targeted therapeutically in the future. Disclosures E. Garcia-Melchor None. G. Cafaro None. S. Sood None. L.A.N. Crowe None. M. McLean None. I.B. McInnes None. M. Akbar None. N.L. Millar None.


Author(s):  
Izabela K. Piechocka ◽  
Sarah Keary ◽  
Alberto Sosa-Costa ◽  
Lukas Lau ◽  
Nitin Mohan ◽  
...  

Author(s):  
Paulina Akeus ◽  
Louis Szeponik ◽  
Veronica Langenes ◽  
Viktoria Karlsson ◽  
Patrik Sundström ◽  
...  

2021 ◽  
pp. annrheumdis-2020-219335
Author(s):  
Emma Garcia-Melchor ◽  
Giacomo Cafaro ◽  
Lucy MacDonald ◽  
Lindsay A N Crowe ◽  
Shatakshi Sood ◽  
...  

ObjectivesIncreasing evidence suggests that inflammatory mechanisms play a key role in chronic tendon disease. After observing T cell signatures in human tendinopathy, we explored the interaction between T cells and tendon stromal cells or tenocytes to define their functional contribution to tissue remodelling and inflammation amplification and hence disease perpetuation.MethodsT cells were quantified and characterised in healthy and tendinopathic tissues by flow cytometry (FACS), imaging mass cytometry (IMC) and single cell RNA-seq. Tenocyte activation induced by conditioned media from primary damaged tendon or interleukin-1β was evaluated by qPCR. The role of tenocytes in regulating T cell migration was interrogated in a standard transwell membrane system. T cell activation (cell surface markers by FACS and cytokine release by ELISA) and changes in gene expression in tenocytes (qPCR) were assessed in cocultures of T cells and explanted tenocytes.ResultsSignificant quantitative differences were observed in healthy compared with tendinopathic tissues. IMC showed T cells in close proximity to tenocytes, suggesting tenocyte–T cell interactions. On activation, tenocytes upregulated inflammatory cytokines, chemokines and adhesion molecules implicated in T cell recruitment and activation. Conditioned media from activated tenocytes induced T cell migration and coculture of tenocytes with T cells resulted in reciprocal activation of T cells. In turn, these activated T cells upregulated production of inflammatory mediators in tenocytes, while increasing the pathogenic collagen 3/collagen 1 ratio.ConclusionsInteraction between T cells and tenocytes induces the expression of inflammatory cytokines/chemokines in tenocytes, alters collagen composition favouring collagen 3 and self-amplifies T cell activation via an auto-regulatory feedback loop. Selectively targeting this adaptive/stromal interface may provide novel translational strategies in the management of human tendon disorders.


2008 ◽  
Vol 2008 ◽  
pp. 1-8 ◽  
Author(s):  
Shumei Man ◽  
Eroboghene E. Ubogu ◽  
Katherine A. Williams ◽  
Barbara Tucky ◽  
Melissa K. Callahan ◽  
...  

Endothelial cells that functionally express blood brain barrier (BBB) properties are useful surrogates for studying leukocyte-endothelial cell interactions at the BBB. In this study, we compared two different endothelial cellular models: transfected human brain microvascular endothelial cells (THBMECs) and human umbilical vein endothelial cells (HUVECs). With each grow under optimal conditions, confluent THBMEC cultures showed continuous occludin and ZO-1 immunoreactivity, while HUVEC cultures exhibited punctate ZO-1 expression at sites of cell-cell contact only. Confluent THBMEC cultures on 24-well collagen-coated transwell inserts had significantly higher transendothelial electrical resistance (TEER) and lower solute permeability than HUVECs. Confluent THBMECs were more restrictive for mononuclear cell migration than HUVECs. Only THBMECs utilized abluminal CCL5 to facilitate T-lymphocyte migration in vitro although both THBMECs and HUVECs employed CCL3 to facilitate T cell migration. These data establish baseline conditions for using THBMECs to develop in vitro BBB models for studying leukocyte-endothelial interactions during neuroinflammation.


Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3648
Author(s):  
Eva-Maria Kamionka ◽  
Baifeng Qian ◽  
Wolfgang Gross ◽  
Frank Bergmann ◽  
Thilo Hackert ◽  
...  

The dominant intrastromal T-cell infiltration in pancreatic cancer is mainly caused by the contact guidance through the excessive desmoplastic reaction and could represent one of the obstacles to an effective immune response in this tumor type. This study analyzed the collagen organization in normal and malignant pancreatic tissues as well as its influence on T-cell distribution in pancreatic cancer. Human pancreatic tissue was analyzed using immunofluorescence staining and multiphoton and SHG microscopy supported by multistep image processing. The influence of collagen alignment on activated T-cells was studied using 3D matrices and time-lapse microscopy. It was found that the stroma of malignant and normal pancreatic tissues was characterized by complex individual organization. T-cells were heterogeneously distributed in pancreatic cancer and there was no relationship between T-cell distribution and collagen organization. There was a difference in the angular orientation of collagen alignment in the peritumoral and tumor-cell-distant stroma regions in the pancreatic ductal adenocarcinoma tissue, but there was no correlation in the T-cell densities between these regions. The grade of collagen alignment did not influence the directionality of T-cell migration in the 3D collagen matrix. It can be concluded that differences in collagen organization do not change the spatial orientation of T-cell migration or influence stromal T-cell distribution in human pancreatic cancer. The results of the present study do not support the rationale of remodeling of stroma collagen organization for improvement of T-cell–tumor cell contact in pancreatic ductal adenocarcinoma.


2020 ◽  
Vol 11 ◽  
Author(s):  
Justin Killick ◽  
Joanne Hay ◽  
Elena Morandi ◽  
Sonja Vermeren ◽  
Saniya Kari ◽  
...  

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS), in which T-cell migration into the CNS is key for pathogenesis. Patients with MS exhibit impaired regulatory T cell populations, and both Foxp3+ Tregs and type I regulatory T cells (Tr1) are dysfunctional. MS is a multifactorial disease and vitamin D deficiency is associated with disease. Herein, we examined the impact of 1,25(OH)2D3 on CD4+ T cells coactivated by either CD28 to induce polyclonal activation or by the complement regulator CD46 to promote Tr1 differentiation. Addition of 1,25(OH)2D3 led to a differential expression of adhesion molecules on CD28- and CD46-costimulated T cells isolated from both healthy donors or from patients with MS. 1,25(OH)2D3 favored Tr1 motility though a Vitamin D-CD46 crosstalk highlighted by increased VDR expression as well as increased CYP24A1 and miR-9 in CD46-costimulated T cells. Furthermore, analysis of CD46 expression on T cells from a cohort of patients with MS supplemented by vitamin D showed a negative correlation with the levels of circulating vitamin D. Moreover, t-Distributed Stochastic Neighbor Embedding (t-SNE) analysis allowed the visualization and identification of clusters increased by vitamin D supplementation, but not by placebo, that exhibited similar adhesion phenotype to what was observed in vitro. Overall, our data show a crosstalk between vitamin D and CD46 that allows a preferential effect of Vitamin D on Tr1 cells, providing novel key insights into the role of an important modifiable environmental factor in MS.


Immunology ◽  
2003 ◽  
Vol 108 (1) ◽  
pp. 32-41 ◽  
Author(s):  
Isabel Correa ◽  
Tim Plunkett ◽  
Anda Vlad ◽  
Arron Mungul ◽  
Jessica Candelora-Kettel ◽  
...  

2019 ◽  
Vol 203 (12) ◽  
pp. 3237-3246
Author(s):  
Dalia E. Gaddis ◽  
Lindsey E. Padgett ◽  
Runpei Wu ◽  
Catherine C. Hedrick

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