scholarly journals T cell–derived interleukin (IL)-21 promotes brain injury following stroke in mice

2014 ◽  
Vol 211 (4) ◽  
pp. 595-604 ◽  
Author(s):  
Benjamin D.S. Clarkson ◽  
Changying Ling ◽  
Yejie Shi ◽  
Melissa G. Harris ◽  
Aditya Rayasam ◽  
...  
Keyword(s):  
T Cells ◽  
Brain Injury ◽  
T Cell ◽  
Cerebral Ischemia ◽  
Reperfusion Injury ◽  
Cd4 T Cells ◽  
Ischemia Reperfusion Injury ◽  
Tissue Injury ◽  
Ischemia Reperfusion ◽  
Intracellular Cytokine Staining

T lymphocytes are key contributors to the acute phase of cerebral ischemia reperfusion injury, but the relevant T cell–derived mediators of tissue injury remain unknown. Using a mouse model of transient focal brain ischemia, we report that IL-21 is highly up-regulated in the injured mouse brain after cerebral ischemia. IL-21–deficient mice have smaller infarcts, improved neurological function, and reduced lymphocyte accumulation in the brain within 24 h of reperfusion. Intracellular cytokine staining and adoptive transfer experiments revealed that brain-infiltrating CD4+ T cells are the predominant IL-21 source. Mice treated with decoy IL-21 receptor Fc fusion protein are protected from reperfusion injury. In postmortem human brain tissue, IL-21 localized to perivascular CD4+ T cells in the area surrounding acute stroke lesions, suggesting that IL-21–mediated brain injury may be relevant to human stroke.

scholarly journals Effects of Theophylline and Cyclohexyladenosine on Brain Injury following Normo- and Hyperglycemic Ischemia: A Histopathologic Study in the Rat

1994 ◽  
Vol 14 (1) ◽  
pp. 166-173 ◽  
Author(s):  
Jie-Gang Zhou ◽  
Joseph R. Meno ◽  
Sean S.-F. Hsu ◽  
H. Richard Winn
Keyword(s):  
Brain Injury ◽  
Cerebral Ischemia ◽  
Reperfusion Injury ◽  
Adenosine Receptor ◽  
Ischemia Reperfusion Injury ◽  
Tissue Injury ◽  
Ischemia Reperfusion ◽  
Ischemic Injury ◽  
Adenosine Receptor Agonist ◽  
Cerebral Ischemic

The present study was designed to determine the effects of theophylline, an adenosine receptor antagonist, and cyclohexyladenosine (CHA), an adenosine receptor agonist, on ischemic brain injury following normo- and hyperglycemic ischemia and reperfusion in fasted male Wistar rats. Moderate hyperglycemia was achieved by administering 17% D-glucose (3 g/kg i.p.), whereas normoglycemic animals received an equal volume of saline. The animals were further divided into two groups: One group was pretreated with either theophylline (0.20 μmol/g i.p.) or an equal volume of saline; the second group received either intraventricular CHA (6.25 nmol) or mock CSF prior to the onset of ischemia. During ischemia, pericranial temperature was maintained at 36°C and EEG was monitored. Cerebral ischemia was induced for 15 min, after which flow was restored and the animals were allowed to recover completely. There were no significant differences in physiologic parameters among the groups studied. Five days following the ischemic episode, the rats were perfused with formalin and the brains sub-serially sectioned (8 μm) in the coronal plane and stained with celestine blue/acid fuchsin. Histopathologic analysis was performed in a blinded fashion to determine percentage of dead neurons. Hyperglycemic animals had significantly greater ischemic injury in CA1, cortex, and caudate than the normoglycemic group (p < 0.01). Moreover, rats pretreated with theophylline had a significantly (p < 0.01) higher percentage of dead neurons in CA1, cortex, and caudate than corresponding controls. On the other hand, rats treated with CHA exhibited significantly (p < 0.01) less cerebral ischemic injury than corresponding controls, in either normo- or hyperglycemic conditions. These data confirm previous studies showing the deleterious effects of hyperglycemia on cerebral ischemia-reperfusion injury. Moreover, our results illustrate a protective effect of adenosine on both normo- and hyperglycemic ischemia-reperfusion injury and thus support the hypothesis that attenuated cerebral ischemic production of adenosine contributes to increased tissue injury observed under hyperglycemic conditions.

scholarly journals Liver grafts from CD39-overexpressing rodents are protected from ischemia reperfusion injury due to reduced numbers of resident CD4+T cells

Hepatology ◽  
2013 ◽  
Vol 57 (4) ◽  
pp. 1597-1606 ◽  
Author(s):  
Sandra Pommey ◽  
Bo Lu ◽  
Jennifer McRae ◽  
John Stagg ◽  
Prue Hill ◽  
...  
Keyword(s):  
T Cells ◽  
Reperfusion Injury ◽  
Cd4 T Cells ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion

Role of α/β and γ/δ T cells in renal ischemia-reperfusion injury

2007 ◽  
Vol 293 (3) ◽  
pp. F741-F747 ◽  
Author(s):  
Kathrin Hochegger ◽  
Tobias Schätz ◽  
Philipp Eller ◽  
Andrea Tagwerker ◽  
Dorothea Heininger ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Renal Ischemia ◽  
Wild Type ◽  
Renal Ischemia Reperfusion Injury ◽  
Deficient Mice

T cells have been implicated in the pathogenesis of renal ischemia-reperfusion injury (IRI). To date existing data about the role of the T cell receptor (Tcr) are contradictory. We hypothesize that the Tcr plays a prominent role in the late phase of renal IRI. Therefore, renal IRI was induced in α/β, γ/δ T cell-deficient and wild-type mice by clamping renal pedicles for 30 min and reperfusing for 24, 48, 72, and 120 h. Serum creatinine increased equally in all three groups 24 h after ischemia but significantly improved in Tcr-deficient animals compared with wild-type controls after 72 h. A significant reduction in renal tubular injury and infiltration of CD4+ T-cells in both Tcr-deficient mice compared with wild-type controls was detected. Infiltration of α/β T cells into the kidney was reduced in γ/δ T cell-deficient mice until 72 h after ischemia. In contrast, γ/δ T cell infiltration was equal in wild-type and α/β T cell-deficient mice, suggesting an interaction between α/β and γ/δ T cells. Data from γ/δ T cell-deficient mice were confirmed by in vivo depletion of γ/δ T cells in C57BL/6 mice. Whereas α/β T cell-deficient mice were still protected after 120 h, γ/δ T cell-deficient mice showed a “delayed wild-type phenotype” with a dramatic increase in kidney-infiltrating α/β, Tcr-expressing CD4+ T-cells. This report provides further evidence that α/β T cells are major effector cells in renal IRI, whereas γ/δ T cells play a role as mediator cells in the first 72 h of renal IRI.

scholarly journals A Unique Population of Regulatory T Cells in Heart Potentiates Cardiac Protection From Myocardial Infarction

Circulation ◽  
2020 ◽  
Vol 142 (20) ◽  
pp. 1956-1973
Author(s):  
Ni Xia ◽  
Yuzhi Lu ◽  
Muyang Gu ◽  
Nana Li ◽  
Meilin Liu ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
T Cells ◽  
T Cell ◽  
Reperfusion Injury ◽  
T Cell Receptor ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Cell Receptor ◽  
Interleukin 33 ◽  
Injured Myocardium

Background: Regulatory T cells (Tregs), traditionally recognized as potent suppressors of immune response, are increasingly attracting attention because of a second major function: residing in parenchymal tissues and maintaining local homeostasis. However, the existence, unique phenotype, and function of so-called tissue Tregs in the heart remain unclear. Methods: In mouse models of myocardial infarction (MI), myocardial ischemia/reperfusion injury, or cardiac cryoinjury, the dynamic accumulation of Tregs in the injured myocardium was monitored. The bulk RNA sequencing was performed to analyze the transcriptomic characteristics of Tregs from the injured myocardium after MI or ischemia/reperfusion injury. Photoconversion, parabiosis, single-cell T-cell receptor sequencing, and adoptive transfer were applied to determine the source of heart Tregs. The involvement of the interleukin-33/suppression of tumorigenicity 2 axis and Sparc (secreted acidic cysteine-rich glycoprotein), a molecule upregulated in heart Tregs, was further evaluated in functional assays. Results: We showed that Tregs were highly enriched in the myocardium of MI, ischemia/reperfusion injury, and cryoinjury mice. Transcriptomic data revealed that Tregs isolated from the injured hearts had plenty of differentially expressed transcripts in comparison with their lymphoid counterparts, including heart-draining lymphoid nodes, with a phenotype of promoting infarct repair, indicating a unique characteristic. The heart Tregs were accumulated mainly because of recruitment from the circulating Treg pool, whereas local proliferation also contributed to their expansion. Moreover, a remarkable case of repeatedly detected T-cell receptor of heart Tregs, more than that of spleen Tregs, suggests a model of clonal expansion. Besides, Helios high Nrp-1 high phenotype proved the mainly thymic origin of heart Tregs, with a small contribution of phenotypic conversion of conventional CD4 + T cells, proved by the analysis of T-cell receptor repertoires and conventional CD4 + T cells adoptive transfer experiments. The interleukin-33/suppression of tumorigenicity 2 axis was essential for sustaining heart Treg populations. Last, we demonstrated that Sparc, which was highly expressed by heart Tregs, acted as a critical factor to protect the heart against MI by increasing collagen content and boosting maturation in the infarct zone. Conclusions: We identified and characterized a phenotypically and functionally unique population of heart Tregs that may lay the foundation to harness Tregs for cardioprotection in MI and other cardiac diseases.

Contrasting roles for STAT4 and STAT6 signal transduction pathways in murine renal ischemia-reperfusion injury

2003 ◽  
Vol 285 (2) ◽  
pp. F319-F325 ◽  
Author(s):  
Naoko Yokota ◽  
Melissa Burne-Taney ◽  
Lorraine Racusen ◽  
Hamid Rabb
Keyword(s):  
T Cells ◽  
Reperfusion Injury ◽  
Cd4 T Cells ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Renal Ischemia ◽  
Wild Type ◽  
Renal Ischemia Reperfusion Injury ◽  
Ifn Γ ◽  
Deficient Mice

Recent data support a modulatory role for CD4 T cells in experimental renal ischemia-reperfusion injury (IRI). CD4 T cells can functionally differentiate to either a Th1 (IFN-γ producing) or the counterbalancing Th2 (IL-4) phenotype. The enzymes signal transducers and activators of transcription (STAT) 4 and STAT6 regulate Th1 or Th2 differentiation and cytokine production, respectively. We therefore hypothesized that mice that were STAT4 deficient would be protected from renal IRI and that STAT6-deficient mice would have a more severe course. Intracellular cytokine staining of splenocytes from STAT4–/– or STAT6–/– exhibited distinct IFN-γ and IL-4 cytokine expression profiles. STAT6–/– had markedly worse renal function and tubular injury postischemia compared with wild type. STAT4–/– had only mildly improved function. Renal phagocyte infiltration and ICAM-1 upregulation were similar in STAT4–/–, STAT6–/–, and wild type. To evaluate if the mechanism of the marked worsening in the STAT6–/– mice could be due to IL-4 deficiency, IL-4-deficient mice were studied and had similar postischemic phenotype to STAT6–/– mice. These data demonstrate that the STAT6 pathway has a major protective role in renal IRI. IL-4 deficiency is a likely mechanism underlying the STAT6 effect. A “yin-yang” role for inflammation is emerging in renal IRI, similar to recent observations in atherosclerosis.

scholarly journals A Role for Human Renal Tubular Epithelial Cells in Direct Allo-Recognition by CD4+ T-Cells and the Effect of Ischemia-Reperfusion

2021 ◽  
Vol 22 (4) ◽  
pp. 1733
Author(s):  
Theodoros Eleftheriadis ◽  
Georgios Pissas ◽  
Marta Crespo ◽  
Evdokia Nikolaou ◽  
Vassilios Liakopoulos ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Acute Rejection ◽  
Cd4 T Cells ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Tubular Epithelial Cells ◽  
Renal Tubular Epithelial Cells ◽  
Hla Dr ◽  
Renal Tubular

Direct allorecognition is the earliest and most potent immune response against a kidney allograft. Currently, it is thought that passenger donor professional antigen-presenting cells (APCs) are responsible. Further, many studies support that graft ischemia-reperfusion injury increases the probability of acute rejection. We evaluated the possible role of primary human proximal renal tubular epithelial cells (RPTECs) in direct allorecognition by CD4+ T-cells and the effect of anoxia-reoxygenation. In cell culture, we detected that RPTECs express all the required molecules for CD4+ T-cell activation (HLA-DR, CD80, and ICAM-1). Anoxia-reoxygenation decreased HLA-DR and CD80 but increased ICAM-1. Following this, RPTECs were co-cultured with alloreactive CD4+ T-cells. In T-cells, zeta chain phosphorylation and c-Myc increased, indicating activation of T-cell receptor and co-stimulation signal transduction pathways, respectively. T-cell proliferation assessed with bromodeoxyuridine assay and with the marker Ki-67 increased. Previous culture of RPTECs under anoxia raised all the above parameters in T-cells. FOXP3 remained unaffected in all cases, signifying that proliferating T-cells were not differentiated towards a regulatory phenotype. Our results support that direct allorecognition may be mediated by RPTECs even in the absence of donor-derived professional APCs. Also, ischemia-reperfusion injury of the graft may enhance the above capacity of RPTECs, increasing the possibility of acute rejection.

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