scholarly journals Endothelial-T cell crosstalk contributes to vascular injury in fatty liver disease

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
C Cheung ◽  
C Y Ng ◽  
K L Lee ◽  
K X Wu ◽  
F W J Chioh ◽  
...  
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
Liver Disease ◽  
T Cell ◽  
Endothelial Dysfunction ◽  
Vascular Injury ◽  
Fatty Liver Disease ◽  
Healthy Controls ◽  
Cell Chemotaxis ◽  
Cell Crosstalk

Abstract   Cardiovascular complications are often the fundamental causes of death in non-alcoholic fatty liver disease (NAFLD) patients. While there are known systemic mediators in NAFLD that may induce vascular inflammation, the mechanism of endothelial dysfunction remain understudied. In this work, we harnessed the replicative potential of blood outgrowth endothelial cells (BOECs) to develop personalized cell lines from NAFLD patients and healthy controls. Our transcriptomic analysis showed that the top interactome network enriched in NAFLD BOECs comprised of several C-C and C-X-C chemokine ligands involved in immune cell chemotaxis. We previously reported T cell infiltration in mouse model of non-alcoholic steatohepatitis, and here, we confirmed enhanced endothelial chemokine signatures in arterial histological sections. To elucidate endothelial-immune crosstalk, we performed single-cell analysis on human peripheral blood mononuclear cells and found T cell intensification in NAFLD patients compared to healthy controls. Our immunoprofiling by flow cytometry further revealed that NAFLD patients possessed higher levels CD8+ memory cells. Functionally, T cells, instead of monocytes, adhered more pronouncedly to NAFLD BOECs. In evaluating the CXCL12-CXCR4 axis in chemotaxis, CXCR4 antagonist (AMD3100) substantially modulated the migration of patient-derived CD8+ T cells towards NAFLD BOECs, which was not observed in healthy endothelial-T cell chemotaxis coculture. Finally, we validated NAFLD-associated endothelial dysfunction by enumerating two folds more circulating endothelial cells, a biomarker of vascular injury, in the blood samples of NAFLD patients than healthy controls. Our work provides insights for translation to restore blood vessel health and potentially mitigate adverse vascular events in NAFLD. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Industrial Alignment Fund Pre-Positioning grant from the Agency for Science, Technology and Research, Singapore Endothelial-T cell crosstalk in NAFLD

Abstract 46: FOXP3+ T Regulatory Lymphocytes Counteract Angiotensin II-Induced Vascular Injury

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Muhammad Oneeb Rehman Mian ◽  
Tlili Barhoumi ◽  
Marie Briet ◽  
Adriana Cristina Ene ◽  
Asia Rehman ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Endothelial Dysfunction ◽  
T Lymphocytes ◽  
Vascular Injury ◽  
Mesenteric Arteries ◽  
Ros Production ◽  
Ang Ii ◽  
Induced Hypertension ◽  
Regulatory Lymphocytes

Introduction: T lymphocytes participate in the low-grade inflammatory response that causes vascular injury in angiotensin (Ang) II-induced hypertension. Ang II-induced hypertension and endothelial dysfunction are blunted in T and B lymphocyte-deficient ( Rag1 -/- ) mice, and restored with reconstitution of T cells. However, the role of T regulatory lymphocytes (Treg) in Ang II-induced vascular injury is unclear. We hypothesized that adoptive transfer of FOXP3-deficient (Scurfy) T lymphocytes vs. wild-type (WT) cells will exacerbate Ang II-induced vascular damage in Rag1 -/- mice. Methods: Eleven-week old male Rag1 -/- mice were injected IV with PBS/2% FBS (control), 10 7 WT or Scurfy T lymphocytes, and 2 weeks later underwent sham surgery or were infused with Ang II (490 ng/kg/min, s.c.) using mini-osmotic pumps for 14 days (n=3-8). Systolic (SBP) and diastolic (DBP) blood pressure were measured by telemetry. Vascular function and structure were assessed in second order mesenteric arteries by pressurized myography. Reactive oxygen species (ROS) production and fibronectin and collagen I and III expression were determined in aorta. Results: Ang II induced a 40 mmHg SBP rise in Rag1 -/- mice for all treatment groups, but DBP rise was ~10 mmHg greater for WT and Scurfy T cell-injected mice than for control mice ( P <0.01). Adoptive transfer of WT T cells restored Ang II induced-endothelial dysfunction in mesenteric arteries ( P <0.05), which was exaggerated in Scurfy T cell-injected mice ( P <0.01). Ang II induced a greater increase in ROS production in aortic perivascular fat of Scurfy T cell-injected mice compared to WT T cell-injected mice ( P <0.05). Ang II induced mesenteric artery stiffness ( P <0.01) and hypertrophic remodeling ( P <0.05) in control and Scurfy T cell-injected mice, but not in WT T cell-injected mice. Ang II increased fibronectin expression to a greater extent in the aorta of control and Scurfy T cell-injected mice compared to WT T cell-injected mice ( P <0.01). Collagen I and III content was greater in the aorta of control and Scurfy T cell-injected mice than in WT T cell-injected mice ( P <0.01), but expression was unaltered by Ang II treatment. Conclusion: Foxp3+ T regulatory lymphocytes have a protective role against Ang II-induced vascular remodeling.

scholarly journals Evaluation of the Effect Derived from Silybin with Vitamin D and Vitamin E Administration on Clinical, Metabolic, Endothelial Dysfunction, Oxidative Stress Parameters, and Serological Worsening Markers in Nonalcoholic Fatty Liver Disease Patients

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Alessandro Federico ◽  
Marcello Dallio ◽  
Mario Masarone ◽  
Antonietta Gerarda Gravina ◽  
Rosa Di Sarno ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Liver Disease ◽  
Growth Factor ◽  
Endothelial Dysfunction ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Fatty Liver Disease ◽  
Healthy Controls ◽  
Metabolic Markers ◽  
Nonalcoholic Fatty Liver

Nowadays, the nonalcoholic fatty liver disease represents the main chronic liver disease in the Western countries, and the correct medical therapy remains a big question for the scientific community. The aim of our study was to evaluate the effect derived from the administration for six months of silybin with vitamin D and vitamin E (RealSIL 100D®) on metabolic markers, oxidative stress, endothelial dysfunction, and worsening of disease markers in nonalcoholic fatty liver disease patients. We enrolled 90 consecutive patients with histological diagnosis of nonalcoholic fatty liver disease and 60 patients with diagnosis of reflux disease (not in therapy) as healthy controls. The nonalcoholic fatty liver disease patients were randomized into two groups: treated (60 patients) and not treated (30 patients). We performed a nutritional assessment and evaluated clinical parameters, routine home tests, the homeostatic model assessment of insulin resistance, NAFLD fibrosis score and fibrosis-4, transient elastography and controlled attenuation parameter, thiobarbituric acid reactive substances, tumor necrosis factor α, transforming growth factor β, interleukin-18 and interleukin-22, matrix metalloproteinase 2, epidermal growth factor receptor, insulin growth factor-II, cluster of differentiation-44, high mobility group box-1, and Endocan. Compared to the healthy controls, the nonalcoholic fatty liver disease patients had statistically significant differences for almost all parameters evaluated at baseline (p<0.05). Six months after the baseline, the proportion of nonalcoholic fatty liver disease patients treated that underwent a statistically significant improvement in metabolic markers, oxidative stress, endothelial dysfunction, and worsening of disease was greater than not treated nonalcoholic fatty liver disease patients (p<0.05). Even more relevant results were obtained for the same parameters by analyzing patients with a concomitant diagnosis of metabolic syndrome (p<0.001). The benefit that derives from the use of RealSIL 100D could derive from the action on more systems able to advance the pathology above all in that subset of patients suffering from concomitant metabolic syndrome.

scholarly journals Convalescent COVID-19 patients are susceptible to endothelial dysfunction due to persistent immune activation

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Florence WJ Chioh ◽  
Siew-Wai Fong ◽  
Barnaby E Young ◽  
Kan-Xing Wu ◽  
Anthony Siau ◽  
...  
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
Endothelial Dysfunction ◽  
Acute Infection ◽  
Vascular Complications ◽  
Circulating Endothelial Cells ◽  
Healthy Controls ◽  
Vascular Events ◽  
Activation Markers ◽  
The Impact

Numerous reports of vascular events after an initial recovery from COVID-19 form our impetus to investigate the impact of COVID-19 on vascular health of recovered patients. We found elevated levels of circulating endothelial cells (CECs), a biomarker of vascular injury, in COVID-19 convalescents compared to healthy controls. In particular, those with pre-existing conditions (e.g., hypertension, diabetes) had more pronounced endothelial activation hallmarks than non-COVID-19 patients with matched cardiovascular risk. Several proinflammatory and activated T lymphocyte-associated cytokines sustained from acute infection to recovery phase, which correlated positively with CEC measures, implicating cytokine-driven endothelial dysfunction. Notably, we found higher frequency of effector T cells in our COVID-19 convalescents compared to healthy controls. The activation markers detected on CECs mapped to counter receptors found primarily on cytotoxic CD8+ T cells, raising the possibility of cytotoxic effector cells targeting activated endothelial cells. Clinical trials in preventive therapy for post-COVID-19 vascular complications may be needed.

scholarly journals T Cell Subsets and Natural Killer Cells in the Pathogenesis of Nonalcoholic Fatty Liver Disease

2021 ◽  
Vol 22 (22) ◽  
pp. 12190
Author(s):  
Yoseph Asmelash Gebru ◽  
Haripriya Gupta ◽  
Hyeong Seop Kim ◽  
Jung A. Eom ◽  
Goo Hyun Kwon ◽  
...  
Keyword(s):  
T Cells ◽  
Liver Disease ◽  
T Cell ◽  
Fatty Liver ◽  
Nk Cells ◽  
Nonalcoholic Fatty Liver Disease ◽  
Natural Killer ◽  
Fatty Liver Disease ◽  
T Cell Subsets ◽  
Nonalcoholic Fatty Liver

Nonalcoholic fatty liver disease (NAFLD) is a condition characterized by hepatic accumulation of excess lipids. T cells are commonly classified into various subsets based on their surface markers including T cell receptors, type of antigen presentation and pathophysiological functions. Several studies have implicated various T cell subsets and natural killer (NK) cells in the progression of NAFLD. While NK cells are mainly components of the innate hepatic immune system, the majority of T cell subsets can be part of both the adaptive and innate systems. Several studies have reported that various stages of NAFLD are accompanied by the accumulation of distinct T cell subsets and NK cells with different functions and phenotypes observed usually resulting in proinflammatory effects. More importantly, the overall stimulation of the intrahepatic T cell subsets is directly influenced by the homeostasis of the gut microbiota. Similarly, NK cells have been found to accumulate in the liver in response to pathogens and tumors. In this review, we discussed the nature and pathophysiological roles of T cell subsets including γδ T cells, NKT cells, Mucosal-associated invariant T (MAIT) cells as well as NK cells in NAFLD.

Abstract 098: Foxp3+ T Regulatory Lymphocytes Counteract Angiotensin Ii-induced Vascular Injury

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Muhammad Oneeb Rehman Mian ◽  
Tlili Barhoumi ◽  
Marie Briet ◽  
Adriana Cristina Ene ◽  
Asia Rehman ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Endothelial Dysfunction ◽  
Vascular Injury ◽  
Adoptive Transfer ◽  
Ros Production ◽  
Ang Ii ◽  
Fibronectin Expression ◽  
Induced Hypertension ◽  
Regulatory Lymphocytes

Objective: T effector lymphocytes contribute to vascular injury in angiotensin (Ang) II-induced hypertension, but the role of T regulatory lymphocytes (Tregs) is unclear. Ang II-induced hypertension is blunted in T and B lymphocyte-deficient (Rag1-/-) mice, and restored with reconstitution of T cells. We hypothesized that adoptive transfer of FOXP3-deficient Scurfy (Sf) vs. wild-type (WT) T cells will exacerbate Ang II-induced vascular damage in Rag1-/- mice. Methods: Eleven-week old male Rag1-/- mice were injected IV with vehicle, 10 million WT or Sf T cells, 1 million CD4+CD25+ Tregs alone or with Sf T cells, and 2 weeks later were infused or not with Ang II (490 ng/kg/min, SC) for 14 days (n=3-8). Telemetric BP, vascular function and structure, and reactive oxygen species (ROS) production and fibronectin expression in mesenteric arteries (MA) were determined. Results: Ang II induced a 40 mmHg systolic BP rise in all the groups, but diastolic BP rise was ~10 mmHg greater in WT and Sf T cell-injected mice than in controls (P<0.01). Treg injection alone or with Sf T cells prevented or delayed by 7 days the BP rise, respectively (P<0.05). Ang II did not induce endothelial dysfunction in vehicle or Treg only-injected mice. Adoptive transfer of WT T cells restored Ang II induced-endothelial dysfunction (60±5% vs. 83±4%, P<0.05), which was exaggerated in Sf T cell-injected mice (56±6% vs. 97±7%, P<0.01), but reduced by Treg co-injection (74±4%, P<0.05). Ang II increased ROS production in MA wall (239±32% vs. 119±20%) and perivascular fat (369±39% vs. 84±8%) in Sf T cell-injected mice (P<0.01), but not when co-injected with Tregs. Ang II induced increased vascular stiffness (P<0.01) and media/lumen (M/L, P<0.05) in vehicle (strain at 140 mmHg: 0.60±0.02 vs. 0.80±0.02; M/L: 4.1±0.2 vs. 2.9±0.2%) and Sf T cell-injected mice (strain at 140 mmHg: 0.63±0.01 vs. 0.89±0.04; M/L: 4.7±0.3 vs. 2.9±0.1%). Ang II increased MA fibronectin expression (P<0.01) in vehicle (113±12 vs. 51±14 RFU/μm2) and Sf T cell-injected mice (85±7 vs. 36±9 RFU/μm2). Conclusion: These results demonstrate that Foxp3+ Tregs have a protective role against Ang II-induced vascular dysfunction, remodeling and oxidative stress.

scholarly journals AB0345 Th9 CELLS AND THEIR ASSOCIATED CYTOKINES: THE PROBABLE PLAYERS IN SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) AND TYPE 1 DIABETES MELLITUS (T1DM)

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1197.2-1198
Author(s):  
N. Mohannad ◽  
M. Moaaz ◽  
R. Mohamed Shehata
Keyword(s):  
T Cells ◽  
T Cell ◽  
Disease Activity ◽  
Clinical Manifestations ◽  
Moderate Activity ◽  
Healthy Controls ◽  
Group I ◽  
Pancreatic Islets Of Langerhans ◽  
Th9 Cells ◽  
Significant Difference

Background:SLE is an autoimmune disease (AID) of unknown origin. Several factors can contribute to immune dysfunction in SLE.Interleukin 9 (IL9) is a newly emerging T cell-derived factor preferentially expressed by CD4+T cells: T helper 9 (Th9)IL9 targets different cell lineages, and can contribute to the development of allergic & AIDsWhether abnormal expression and secretion of IL9 are present in SLE patients (pts) still unidentified. It is also unclear whether IL9 exerts main proinflammatory or anti-inflammatory activities in SLE. T1DM is characterized by inflammation of the pancreatic islets of Langerhans. Insulitis progresses over time and β cells become destroyed then clinical DM is established. T1DM is regarded as a T cell-driven AIDObjectives:Evaluation of the expression of CD4+ IL9+ T cells & the level of IL9 in SLE pts compared to both healthy subjects & pts with another AID: T1DM.Also, to evaluate the correlation of these expressions with clinical features, laboratory parameters and SLE activityMethods:The study included: Group I 25 SLE pts fulfilling SLICC classification criteria divided into 2 subgroups (gps) according to SLE disease activity index (SLEDAI) IA: 20 pts with mild to moderate activity (<12) IB:5 pts with severe activity (>12) recruited from rheumatology clinic or internal medicine ward (Rheumatology unit), Main University Hospital, Alexandria. Group II 15 healthy individuals as a first control gp. Group III 15 pts with T1DM fulfilling the American Diabetes Association criteria as a second control gp. All pts were subjected to history taking, clinical examination,laboratory investigations: CBC,LFT,KFT,ESR,CRP,ANA,Anti-dsDNA,Th9 cell expression detection by flowcytometry and serum IL9 by ELISAResults:There was no statistical difference between all gps as regards age & sex but a significant increased ESR in SLE compared to controls & T1DM p< 0.001 p=0.001Th9 expression was highly increased in SLE pts, range 0.13-4.54% & mean ±SD=1.50 ± 1.47% than both control gps. In healthy controls Th9 ranged between 0.0-1.29% with mean 0.37 ±0.52%, while in T1DM pts ranged between 0.03 to 2.13% with mean of 0.67 ± 0.59%. A high significant difference was found between SLE pts and controls p=0.001, an insignificant rise was seen in SLE pts compared to T1DM pts p=0.157. A high significant increase in Th9 was found in severe SLE: mean of 3.74 ±1.15% than in pts with mild to moderate SLE: mean 0.94±0.88% p=<0.001IL9 level was highly increased in SLE pts: mean of 42.83± 23.98 pg/ml than both control gps. In healthy controls the mean was 8.54±13.27, while in T1DM with mean of 29.17±16.09 pg/ml. A high significant difference was found between SLE pts and normal controls p<0.001 but an insignificant rise with T1DM p=0.294. A high significant increase in IL9 in pts with severe ds compared to mild to moderate pts p<0.001.A significant direct correlation between Th9 & IL9 and SLEDAI/105 A significant direct correlation between damage index and Th9 p=0.040 but not IL9 p=0.053In SLE no significant relation between Th9 or IL9 & clinical manifestations or disease duration. A direct correlations between Th9 & ESR p=0.046 and CRP p=0.025,a significant correlation between IL9 and CRP p=0.033, no correlations between Th9&IL9 level and anti-dsDNA p=0.593& 0.4 Significant direct correlation between Th9 and IL9 in T1DM pts, still no correlation with glycemic profile. IL9 levels were significantly increased in SLE with elevated CRP p=0.033 & the % of Th9 cells were increased with elevated ESR and CRP p=0.025, 0.046Conclusion:In SLE pts; IL9 level and Th9 cells expression were significantly elevated compared to healthy controls. IL9 levels and the percentages of Th9 directly correlated with the SLE disease activity. IL9 levels also were significantly increased in T1DM pts compared to controls,but they were less expressed than in SLE. This suggests an important role of IL9 in the pathogenesis AIDs as SLEReferences:[1]Tahernia L et al. Cytokines in SLE: their role in pathogenesis of disease and possible therapeutic opportunities. Rheum Res 2017Disclosure of Interests:None declared

scholarly journals AB0133 INCREASED SOLUBLE SEMAPHORIN 4D/CD100 IN THE PLASMA OF SJÖGREN’S SYNDROME AND ITS EFFECTS ON HUMAN SALIVARY GLAND CELL AND CD4+ T CELL

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1367.1-1367
Author(s):  
S. E. Kang ◽  
S. U. Kim ◽  
R. H. Kim ◽  
H. J. Yoo ◽  
Y. J. Lee ◽  
...  
Keyword(s):  
T Cells ◽  
Salivary Gland ◽  
T Cell ◽  
Tight Junction ◽  
Sjogren's Syndrome ◽  
Healthy Controls ◽  
Human Salivary Gland ◽  
Semaphorin 4D ◽  
Aqp5 Expression ◽  
Ifn Γ

Background:Semaphorin 4D (SEMA4D) / CD100, known as a subfamily of axonal guidance proteins, has also been reported to act as an immunoregulator in several infectious and inflammatory diseases [1]. Sjögren’s syndrome (SS) is a systemic autoimmune disease that primarily affects the exocrine glands by infiltrated lymphocytes resulting in dryness of mouth and eyes. IL-17 was reported to impair the integrity of tight junction barrier and attenuate the expression of aquaporin 5 (AQP5), causing salivary gland dysfunction in SS [2].Objectives:This study was aimed to evaluate the role of SEMA4D in patients with SS and investigate the effect of SEMA4D on human salivary gland epithelial cell (SGEC) and T cell.Methods:Soluble SEMA4D levels in plasma were measured by enzyme-linked immunosorbent assay (ELISA) from patients with SS, non-SS sicca and healthy controls. Immortalized human SGECs, originated from acini (NS-SV-AC) and duct (NS-SV-DC), were used to evaluate the effects of SEMA4D. CD4+T cells from human peripheral blood were isolated to determine the secretion of cytokines in response to SEMA4D. IFN-γ and IL-17 were used to determine the effects on AQP5 expression of SGEC.Results:The levels of soluble SEMA4D in plasma were increased in patients with SS (median [interquartile range]: 1221.3 [393.5] pg/mL) compared to non-SS sicca (940.2 [355.1] pg/mL,p= 0.006) or healthy controls (909.5 [108.0] pg/mL,p <0.0001). The levels of soluble SEMA4D in plasma were correlated with the levels of several autoantibodies including anti-SSA (Spearman’s rho = 0.358,p= 0.006), anti-SSB (rho = 0.350,p= 0.007), and anti-muscarinic receptor 3 (M3R) Ab (rho = 0.495,p< 0.001), and also correlated with total IgG (rho = 0.431,p= 0.002). SEMA4D-stimulated SGECs showed decreased expression of tight junctions such as occludin and Zo-1. CD4+T cells secreted IFN-γ (p= 0.025), IL-17 (p= 0.028), and IL-21 (p= 0.007) with SEMA4D stimulation. IFN-γ and IL-17 decreased AQP5 expression in SGECs.Conclusion:SEMA4D contributed to decreased expression of tight junction in SGECs. SEMA4D induced production of IFN-γ and IL-17 in CD4+T cells and these cytokine decreased AQP5 expression in SGECs.References:[1]Worzfeld T, Offermanns S. Nat Rev Drug Discov. 2014;13(8):603-21.[2]Bhattarai KR, Junjappa R, Handigund M, Kim HR, Chae HJ. Autoimmun Rev. 2018;17(4):376-90.Disclosure of Interests:None declared

Anti-CD20 therapy corrects a CD8 regulatory T cell deficit in multiple sclerosis

2021 ◽  
pp. 135245852110033
Author(s):  
Quentin Howlett-Prieto ◽  
Xuan Feng ◽  
John F Kramer ◽  
Kevin J Kramer ◽  
Timothy W Houston ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
B Cell ◽  
Regulatory T Cell ◽  
Healthy Controls ◽  
Regulatory Cells ◽  
Long Term Treatment ◽  
Anti Cd20

Objective: To determine the effect of long-term anti-CD20 B-cell-depleting treatment on regulatory T cell immune subsets that are subnormal in untreated MS patients. Methods: 30 clinically stable MS patients, before and over 38 months of ocrelizumab treatment, were compared to 13 healthy controls, 29 therapy-naïve MS, 9 interferon-β-treated MS, 3 rituximab-treated MS, and 3 rituximab-treated patients with other autoimmune inflammatory diseases. CD8, CD28, CD4, and FOXP3 expression in peripheral blood mononuclear cells was quantitated with flow cytometry. Results: CD8+ CD28− regulatory cells rose from one-third of healthy control levels before ocrelizumab treatment (2.68% vs 7.98%), normalized by 12 months (13.5%), and rose to 2.4-fold above healthy controls after 18 months of ocrelizumab therapy (19.0%). CD4+ FOXP3+ regulatory cells were lower in MS than in healthy controls (7.98%) and showed slight long-term decreases with ocrelizumab. CD8+ CD28− and CD4+ FOXP3+ regulatory T cell percentages in IFN-β-treated MS patients were between those of untreated MS and healthy controls. Interpretation: Long-term treatment with ocrelizumab markedly enriches CD8+ CD28− regulatory T cells and corrects the low levels seen in MS before treatment, while slightly decreasing CD4+ FOXP3+ regulatory T cells. Homeostatic enrichment of regulatory CD8 T cells provides a mechanism, in addition to B cell depletion, for the benefits of anti-CD20 treatment in MS.

ALLOANTIGEN-SPECFIC CD8+ T CELLS STIMULATE ENDOTHELIAL CELLS TO PRODUCE THE T CELL CHEMOATTRACTANTS IP-10 AND MIG.

2000 ◽  
Vol 69 (Supplement) ◽  
pp. S378
Author(s):  
Shoji Koga ◽  
Hirohito Kobayashi ◽  
Andrew C. Novick ◽  
Hiroshi Toma ◽  
Robert L. Fairchild
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
T Cell ◽  
Cd8 T Cells

The Rac activator Tiam1 controls efficient T-cell trafficking and route of transendothelial migration

Blood ◽  
2009 ◽  
Vol 113 (24) ◽  
pp. 6138-6147 ◽  
Author(s):  
Audrey Gérard ◽  
Rob A. van der Kammen ◽  
Hans Janssen ◽  
Saskia I. Ellenbroek ◽  
John G. Collard
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
T Cell ◽  
Transendothelial Migration ◽  
Contact Hypersensitivity ◽  
Cell Trafficking ◽  
T Cell Trafficking ◽  
Cell Arrest

Abstract Migration toward chemoattractants is a hallmark of T-cell trafficking and is essential to produce an efficient immune response. Here, we have analyzed the function of the Rac activator Tiam1 in the control of T-cell trafficking and transendothelial migration. We found that Tiam1 is required for chemokine- and S1P-induced Rac activation and subsequent cell migration. As a result, Tiam1-deficient T cells show reduced chemotaxis in vitro, and impaired homing, egress, and contact hypersensitivity in vivo. Analysis of the T-cell transendothelial migration cascade revealed that PKCζ/Tiam1/Rac signaling is dispensable for T-cell arrest but is essential for the stabilization of polarization and efficient crawling of T cells on endothelial cells. T cells that lack Tiam1 predominantly transmigrate through individual endothelial cells (transcellular migration) rather than at endothelial junctions (paracellular migration), suggesting that T cells are able to change their route of transendothelial migration according to their polarization status and crawling capacity.

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