Abstract P617: Angiotensin II-induced Hypertension And Vascular Injury Is Mediated By Gamma/delta T Cells

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Antoine Caillon ◽  
Muhammad Oneeb Rehman Mian ◽  
Tlili Barhoumi ◽  
Pierre Paradis ◽  
Ernesto L. Schiffrin

Objective: Both innate antigen presenting cells and the adaptive immune system have been shown to play a role in the development of hypertension. Nevertheless, the T cell subset involved in the pathophysiology of hypertension remains unclear. There is a small subset of “innate-like” T cells expressing gamma/delta T cell receptor (TCR) rather than the alpha/beta TCR that could play a role in bridging between the innate and adaptive immune systems. However, it is unknown whether gamma/delta T cells contribute to development of hypertension. Method/Results: Thirteen to 15 week-old male C57BL/6 wild-type and Tcrd-/- mice, which are devoid of gamma/delta T cells, were infused or not with angiotensin (Ang) II (490 ng/kg/min, SC) for 7 or 14 days (n=4-9). Telemetric blood pressure, mesenteric artery endothelial function and vascular remodeling by pressurized myography and spleen T cell profile by flow cytometry were evaluated. Fourteen days of Ang II increased systolic blood pressure (167±4 vs 125±2 mmHg, P≤0.01) in wild-type compared to control mice. The frequency of gamma/delta T cells (6±1% vs 3±1%, P≤0.05) and activated (CD69+) gamma/delta T cells (11±1% vs 7±1%) was increased after 7 days of Ang II, and 7 days later were respectively unchanged or further increased (24±2% vs 10±1%) in wild-type compared to control mice. Ang II decreased mesenteric artery relaxation responses to acetylcholine (51±5% vs 88±3%, P≤0.01) and increased media/lumen (5±1 vs 3±0%, P≤0.01) in wild-type mice compare to controls. No gamma/delta T cells were detected in Tcrd-/- treated or not with Ang II. All the above Ang II effects were abrogated in Tcrd-/- mice. Conclusion: These data suggest that gamma/delta T cells mediate Ang II-induced blood pressure rise and vascular injury. Gamma/delta T cells could be key immune cells bridging innate and adaptive immune responses during the development of hypertension.

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Antoine Caillon ◽  
Muhammad O Mian ◽  
Julio C Fraulob-Aquino ◽  
Ku-Geng Huo ◽  
Tlili Barhoumi ◽  
...  

Objective: Both innate antigen-presenting cells and the adaptive immune system have been shown to play a role in the development of hypertension. Nevertheless, the T cell subsets involved in the pathophysiology of hypertension remains unclear. There is a small subset of “innate-like” T cells expressing the γ/δ T cell receptor (TCR) rather than the α/β TCR that could play a role bridging the innate and adaptive immune systems. We previously observed that angiotensin (Ang) II caused an increase in number and activation of γ/δ T cells and Ang II-induced systolic blood pressure (SBP) rise and vascular injury were blunted in Tcr δ -/- mice, which are devoid of γ/δ T cells. In order to further characterize the role of γ/δ T cells in hypertension, we determined whether Ang II-effects would be blunted by antibody-induced depletion of γ/δ T cells. In addition, we tested whether SBP in human could be predicted by combining the expression of genes encoding TCRGC (TCR gamma constant region) and pro-inflammatory markers of γ/δ T cells in peripheral blood mononuclear cells (PBMC). Method and Results: Thirteen to 15-week old male C57BL/6 wild-type (WT) mice were infused with Ang II (490 ng/kg/min, SC) for 14 days and injected IP with anti-γ/δ TCR or control isotype antibodies 1 day before and at day 6 of Ang II infusion. Depletion of γ/δ T cells decreased SBP (147±2 vs 167 ± 3 mm Hg, P <0.05) and restored mesenteric artery relaxation responses to acetylcholine (E max : 90±4 vs 62 ± 8%, P <0.05) compared to isotype antibody-treated mice. Using the SBP data and the PBMC gene expression profile (GSE12288) of 222 human subjects, we predicted with a supervised machine learning approach SBP by combining the gene expression of TCRGC and pro-inflammatory makers including interleukin-17A, interferon-γ and their receptors (R=0.23, P <0.001). Conclusion: Antibody-induced depletion further demonstrates the role of γ/δ T cells in Ang II-induced SBP elevation and vascular injury. Prediction of SBP using PBMC gene expression of γ/δ T cells and pro-inflammatory markers suggests that γ/δ T cells contribute to the development of human hypertension.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A635-A635
Author(s):  
Jeffrey Zhang ◽  
Everett Henry ◽  
L Harris Zhang ◽  
Wanying Zhang

BackgroundResveratrol (3,4’,5-trihydroxystilbene), a stilbenoid isolated from many species of plants, is widely known for its antioxidative, anti-inflammatory, immunomodulatory and anticancer activities. Recently, novel resveratrol oligomers have been isolated from various plants; their diverse structures are characterized by the polymerization of two or more resveratrol units. Little is known regarding the anticancer and immunomodulating activities of these oligomers. In this study, we designed in vitro models to compare resveratrol side by side with its natural dimer NBT-167 for their anticancer and immunological activities.MethodsWe isolated resveratrol and its dimer (NBT-167) from plants. The potency of the compounds was compared side by side using cancer cell survival assays and immunological assays with various types of human cells including cancer cell lines, PBMCs and enriched NK, gamma delta T cells, THP-1 monocytic cells, HL-60 promyelocytic leukemia cells as well as mouse RAW264.7 macrophages.ResultsNBT-167 was found to be more potent than resveratrol in inhibiting growth of various cancer cells and modulation of cytokine production from anti-IgM, LPS, PHA or SEB stimulated PBMC. Both compounds similarly enhanced IL-2 stimulated NK and gamma delta T cell killing activity against K562 cells and modulated nitric oxide production from LPS/IFN-g induced RAW264.7 macrophages and phagocytotic activity of HL-60 cells. NBT-167 was slightly more potently than resveratrol in inhibiting chemotaxis of HL-60 cells and blocking cell cycle of THP-1 and HL-60 cells at G1/S transition. In addition, NBT-167, but not resveratrol, could increase IL-2 production and T cell proliferation stimulated with anti-CD3 and anti-CD28 and synergize with anti-PD-1 antibody to increase IL-2 and IFN-gamma production in co-culture of allotypic T cells and dendric cells (MLR).ConclusionsOur data showed that NBT-167, a dimer of resveratrol, had anticancer and immunomodulatory activities such as modulation of expression of cytokines in immune cells and induction of cancer cell-killing activities of NK and gamma delta T cells. Generally, NBT-167 appeared to have higher activities than resveratrol in modulating immune cells and inhibiting cancer cells. NBT-167 could be a promising cancer immunotherapeutic agent targeting both cancer cells and immune cells.


1993 ◽  
Vol 177 (2) ◽  
pp. 257-263 ◽  
Author(s):  
D Dunon ◽  
M D Cooper ◽  
B A Imhof

Current evidence suggests both thymic and extrathymic origins for T cells. Studies in mice favor an in situ origin for a prominent population of intestinal intraepithelial lymphocytes that express gamma/delta T cell receptor (TCR). This developmental issue is explored in an avian model in which the gamma/delta lymphocytes constitute a major T cell subpopulation that is accessible for study during the earliest stages of lymphocyte development. In the chick embryo, cells bearing the gamma/delta TCR appear first in the thymus where they reach peak levels on days 14-15 of embryogenesis, just 2 d before gamma/delta T cells appear in the intestine. Using two congenic chick strains, one of which expresses the ov antigen, we studied the origin and kinetics of intestinal colonization by gamma/delta T cells. The embryonic gamma/delta+ thymocytes homed to the intestine where they survived for months, whereas an embryonic gamma/delta- thymocyte population enriched in thymocyte precursors failed to give rise to intestinal gamma/delta+ T cells. Embryonic hemopoietic tissues, bone marrow, and spleen, were also ineffective sources for intestinal gamma/delta+ T cells. Intestinal colonization by gamma/delta+ thymocytes occurred in two discrete waves in embryos and newly hatched birds. The data indicate that intestinal gamma/delta T cells in the chicken are primarily thymic migrants that are relatively long-lived.


Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Antoine Caillon ◽  
Pierre Paradis ◽  
Ernesto L Schiffrin

Objective: Both innate (monocyte/macrophages) and adaptive immune cells (T lymphocytes) have been shown to play a role in the development of vascular injury in hypertension. Recently, we demonstrated that a small subset of “innate-like” T lymphocytes, expressing the γ/δ T cell receptor (TCR) rather than the αβ TCR, plays a key role in hypertension and vascular injury. We demonstrated an increased number and activation (CD69 + ) of γδ T cells during the development of hypertension caused by angiotensin (Ang) II infusion, and that deficiency in γδ T cells prevented Ang II-induced hypertension, resistance artery endothelial dysfunction and spleen T-cell activation in mice. We hypothesized that γδ T cells mediate activation of other T cells in hypertension. Method and Results: Fourteen to 15-week old male C57BL/6 wild-type (WT) mice were infused with Ang II (490 ng/kg/min, SC) for 3, 7 and 14 days (n=5-7) and spleen T cell profile was determined by flow cytometry. A correlation was demonstrated between the frequency (FREQ) and the number (#) of activated CD69 + γδ T cells and CD4 + CD69 + T cells (FREQ: r=0.41, P <0.05 and #: r=0.58, P <0.001) and CD8 + CD69 + T cells (FREQ: r=0.36, P <0.05 and #: r=0.50, P <0.01). We also demonstrated a high correlation between the # of CD69 + γδ T cells expressing CD27, a marker of interferon-γ expressing cells and a member of the T-T interaction molecules, with CD4 + CD69 + (r=0.88, P <0.001) and CD8 + CD69 + (r=0.81, P <0.01) T cells after 7 days of Ang II infusion. Conclusion: This study demonstrated an association between CD27 + CD69 + γδ T cells and activated T cells. These results suggest that γδ T cells drive activation of other T cells in Ang II-induced hypertension. Targeting γδ T cells may contribute to reduce inflammation in hypertension.


Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Brandon G Shokoples ◽  
Kevin Comeau ◽  
Akinori Higaki ◽  
Antoine Caillon ◽  
Pierre Paradis ◽  
...  

Background: The P2X7 receptor (P2RX7) recognizes damage associated molecule patterns such as adenosine triphosphate (ATP), and triggers the activation of immune cells. Elevated plasma ATP levels have been observed in hypertensive patients, providing a potential mechanism for P2RX7 activation. Additionally, a hypomorphic polymorphism for P2X7 is correlated with a decreased risk for essential hypertension in Chinese post-menopausal women. However, it is unknown whether P2RX7 activation contributes to angiotensin (Ang) II-induced blood pressure (BP) elevation and vascular damage. We hypothesized that P2rx7 knockout would blunt Ang II-induced BP elevation, vascular injury, and infiltration of activated immune T cells into perivascular adipose tissue (PVAT). Methods: Ten-to-12-week-old male C57BL/6J male wild-type (WT) and P2rx7 -/- mice were infused or not with Ang II (1000ng/kg/min) for 14 days. BP was determined by telemetry, mesenteric artery function and remodeling using pressurized myography, aortic stiffening by ultrasound and infiltration of activated immune T cells in aortic PVAT by flow cytometry. Results: Ang II-infused P2rx7 -/- mice display a reduced systolic BP (164±3 vs. 176±2 mm Hg, P <0.05) and pulse pressure (37±4 vs. 53±3 mm Hg, P <0.001) in comparison to WT mice. Aortic stiffening occurred in WT mice treated with Ang II, demonstrated by an increased pulse wave velocity (7.7±0.7 vs. 5.9±0.3 m/s, P <0.05), accompanied by a 3.8-fold increased infiltration of activated CD8 + T cells in aortic PVAT (60±16 vs 16±3 cells/aortic PVAT, P <0.001), which were both absent in P2rx7 -/- mice (6.4±1.4 vs 5.5±1.1 m/s and 27±7 vs 16±3 cells/aortic PVAT). In addition, the frequency of IFN-γ producing CD8 + T cells in the spleen of Ang II-treated WT mice increased (2.6±0.2% vs 1.2±0.2%), which did not occur in P2rx7 -/- mice (1.7±0.3% vs 1.7±0.2%). Ang II-infusion induced mesenteric artery endothelial dysfunction in WT mice (61±7 vs 83±4% relaxation response to acetylcholine, P <0.05), which was absent in P2rx7 -/- mice (89±3 vs 90±3%). Conclusion: P2rx7 knockout attenuates Ang II-induced hypertension, vascular injury, and infiltration of activated CD8 + T cells into aortic PVAT.


Hypertension ◽  
2018 ◽  
Vol 72 (Suppl_1) ◽  
Author(s):  
Pierre Paradis ◽  
Antoine Caillon ◽  
Ernesto L Schiffrin

1996 ◽  
Vol 183 (5) ◽  
pp. 2271-2282 ◽  
Author(s):  
L Wen ◽  
W Pao ◽  
F S Wong ◽  
Q Peng ◽  
J Craft ◽  
...  

The production of class-switched antibodies, particularly immunoglobulin (Ig) G1 and IgE, occurs efficiently in T cell receptor (TCR) alpha-/- mice that are congenitally devoid of alpha/beta T cells. This finding runs counter to a wealth of data indicating that IgG1 and IgE synthesis are largely dependent on the collaboration between B and alpha/beta T cells. Furthermore, many of the antibodies synthesized in TCR alpha-/- mice are reactive to a similar spectrum of self-antigens as that targeted by autoantibodies characterizing human systemic lupus erythematosus (SLE). SLE, too, is most commonly regarded as an alpha/beta T cell-mediated condition. To distinguish whether the development of autoantibodies in TCR alpha-/- mice is due to an intrinsic de-regulation of B cells, or to a heretofore poorly characterized collaboration between B and "non-alpha/beta T" cells, the phenotype has been reconstituted by transfer of various populations of B and non-alpha/beta T cells including cloned gamma/delta T cells derived from TCR alpha-/- mice, to severe combined immunodeficient (SCID) mice. The results establish that the reproducible production of IgG1 (including autoantibodies) is a product of non-alpha/beta T cell help that can be provided by gamma/delta T cells. This type of B-T collaboration sustains the production of germinal centers, lymphoid follicles that ordinarily are anatomical signatures of alpha/beta T-B cell collaboration. Thus, non-alpha/beta T cell help may drive Ig synthesis and autoreactivity under various circumstances, especially in cases of alpha/beta T cell immunodeficiency.


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