scholarly journals The Induction of Stable Peripheral Tolerance Is a Result of Alloantigen Priming and Independent from Pretransplant T Cells in a Porcine Lung Transplantation Model

2012 ◽  
Vol 94 (10S) ◽  
pp. 478
Author(s):  
G. Büchler ◽  
A.-K. Knöfel ◽  
N. Madrahimov ◽  
K. Dreckmann ◽  
M. Avsar ◽  
...  
Keyword(s):  
T Cells ◽  
Lung Transplantation ◽  
Peripheral Tolerance ◽  
Transplantation Model

Effects of Hypercapnia on Acute Cellular Rejection after Lung Transplantation in Rats

2018 ◽  
Vol 128 (1) ◽  
pp. 130-139 ◽  
Author(s):  
Jing Tan ◽  
Yanhong Liu ◽  
Tao Jiang ◽  
Ling Wang ◽  
Can Zhao ◽  
...  
Keyword(s):  
T Cells ◽  
Lung Transplantation ◽  
Ischemia Reperfusion ◽  
Interleukin 2 ◽  
Weight Ratio ◽  
Acute Cellular Rejection ◽  
Rat Lung ◽  
Sprague Dawley ◽  
Cellular Rejection ◽  
Transplantation Model

Abstract Background Hypercapnia alleviates pulmonary ischemia–reperfusion injury, regulates T lymphocytes, and inhibits immune reaction. This study aimed to evaluate the effect of hypercapnia on acute cellular rejection in a rat lung transplantation model. Methods Recipient rats in sham-operated (Wistar), isograft (Wistar to Wistar), and allograft (Sprague–Dawley to Wistar) groups were ventilated with 50% oxygen, whereas rats in the hypercapnia (Sprague–Dawley to Wistar) group were administered 50% oxygen and 8% carbon dioxide for 90 min during reperfusion (n = 8). Recipients were euthanized 7 days after transplantation. Results The hypercapnia group showed a higher oxygenation index (413 ± 78 vs. 223 ± 24), lower wet weight-to-dry weight ratio (4.23 ± 0.54 vs. 7.04 ± 0.80), lower rejection scores (2 ± 1 vs. 4 ± 1), and lower apoptosis index (31 ± 6 vs. 57 ± 4) as compared with the allograft group. The hypercapnia group showed lower CD8 (17 ± 4 vs. 31 ± 3) and CD68 (24 ± 3 vs. 43 ± 2), lower CD8+ T cells (12 ± 2 vs. 35 ± 6), and higher CD4/CD8 ratio (2.2 ± 0.6 vs. 1.1 ± 0.4) compared to the allograft group. Tumor necrosis factor-α (208 ± 40 vs. 292 ± 49), interleukin-2 (30.6 ± 6.7 vs. 52.7 ± 8.3), and interferon-γ (28.1 ± 4.9 vs. 62.7 ± 10.1) levels in the hypercapnia group were lower than those in allograft group. CD4, CD4+ T cells, and interleukin-10 levels were similar between groups. Conclusions Hypercapnia ameliorated acute cellular rejection in a rat lung transplantation model.

The maintenance of peripheral tolerance following porcine lung transplantation is alloantigen specific

2009 ◽  
Vol 56 (S 01) ◽  
Author(s):  
G Warnecke ◽  
B Kruse ◽  
S Thissen ◽  
M Avsar ◽  
C Matiaske ◽  
...  
Keyword(s):  
Lung Transplantation ◽  
Peripheral Tolerance

scholarly journals Potential Role of Trace Elements (Al, Cu, Zn, and Se) in Multiple Sclerosis Physiopathology

2020 ◽  
Vol 27 (4) ◽  
pp. 163-177
Author(s):  
Mohammad Sadegh Hesamian ◽  
Nahid Eskandari
Keyword(s):  
Multiple Sclerosis ◽  
T Cells ◽  
Trace Elements ◽  
Plasma Cells ◽  
Peripheral Tolerance ◽  
The Central Nervous System ◽  
Living Organisms ◽  
Tolerance Breakdown ◽  
Peripheral Immune Cells

Multiple sclerosis (MS) is an unpredictable disease of the central nervous system. The cause of MS is not known completely, and pathology is specified by involved demyelinated areas in the white and gray matter of the brain and spinal cord. Inflammation and peripheral tolerance breakdown due to Treg cell defects and/or effector cell resistance are present at all stages of the disease. Several invading peripheral immune cells are included in the process of the disease such as macrophages, CD8+ T cells, CD4+ T cells, B cells, and plasma cells. Trace elements are known as elements found in soil, plants, and living organisms in small quantities. Some of them (e.g., Al, Cu, Zn, Mn, and Se) are essential for the body’s functions like catalysts in enzyme systems, energy metabolism, etc. Al toxicity and Cu, Zn, and Se toxicity and deficiency can affect the immune system and following neuron inflammation and degeneration. These processes may result in MS pathology. Of course, factors such as lifestyle, environment, and industrialization can affect levels of trace elements in the human body.

scholarly journals VISTA is a checkpoint regulator for naïve T cell quiescence and peripheral tolerance

Science ◽  
2020 ◽  
Vol 367 (6475) ◽  
pp. eaay0524 ◽  
Author(s):  
Mohamed A. ElTanbouly ◽  
Yanding Zhao ◽  
Elizabeth Nowak ◽  
Jiannan Li ◽  
Evelien Schaafsma ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Subset ◽  
Peripheral Tolerance ◽  
Cell Immune Response ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Naïve T Cell ◽  
Naive T Cell

Negative checkpoint regulators (NCRs) temper the T cell immune response to self-antigens and limit the development of autoimmunity. Unlike all other NCRs that are expressed on activated T lymphocytes, V-type immunoglobulin domain-containing suppressor of T cell activation (VISTA) is expressed on naïve T cells. We report an unexpected heterogeneity within the naïve T cell compartment in mice, where loss of VISTA disrupted the major quiescent naïve T cell subset and enhanced self-reactivity. Agonistic VISTA engagement increased T cell tolerance by promoting antigen-induced peripheral T cell deletion. Although a critical player in naïve T cell homeostasis, the ability of VISTA to restrain naïve T cell responses was lost under inflammatory conditions. VISTA is therefore a distinctive NCR of naïve T cells that is critical for steady-state maintenance of quiescence and peripheral tolerance.

scholarly journals CD28 Costimulation Is Required for In Vivo Induction of Peripheral Tolerance in CD8 T Cells

2002 ◽  
Vol 197 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Melanie S. Vacchio ◽  
Richard J. Hodes
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Tolerance Induction ◽  
Peripheral Tolerance ◽  
Cd8 Cells ◽  
Costimulatory Signal ◽  
Cd28 Costimulation

Whereas ligation of CD28 is known to provide a critical costimulatory signal for activation of CD4 T cells, the requirement for CD28 as a costimulatory signal during activation of CD8 cells is less well defined. Even less is known about the involvement of CD28 signals during peripheral tolerance induction in CD8 T cells. In this study, comparison of T cell responses from CD28-deficient and CD28 wild-type H-Y–specific T cell receptor transgenic mice reveals that CD8 cells can proliferate, secrete cytokines, and generate cytotoxic T lymphocytes efficiently in the absence of CD28 costimulation in vitro. Surprisingly, using pregnancy as a model to study the H-Y–specific response of maternal T cells in the presence or absence of CD28 costimulation in vivo, it was found that peripheral tolerance does not occur in CD28KO pregnants in contrast to the partial clonal deletion and hyporesponsiveness of remaining T cells observed in CD28WT pregnants. These data demonstrate for the first time that CD28 is critical for tolerance induction of CD8 T cells, contrasting markedly with CD28 independence of in vitro activation, and suggest that the role of CD28/B7 interactions in peripheral tolerance of CD8 T cells may differ significantly from that of CD4 T cells.

scholarly journals Tissue-specific expression of B7x protects from CD4 T cell–mediated autoimmunity

2011 ◽  
Vol 208 (8) ◽  
pp. 1683-1694 ◽  
Author(s):  
Joyce Wei ◽  
P’ng Loke ◽  
Xingxing Zang ◽  
James P. Allison
Keyword(s):  
T Cells ◽  
Pancreatic Islets ◽  
Peripheral Tolerance ◽  
Wild Type ◽  
Autoimmune Encephalomyelitis ◽  
Specific Expression ◽  
Tissue Specific ◽  
Disease Induction ◽  
Deficient Mice ◽  
Experimental Autoimmune

B7x, an inhibitory member of the B7/CD28 superfamily, is highly expressed in a broad range of nonhematopoietic organs, suggesting a role in maintaining peripheral tolerance. As endogenous B7x protein is expressed in pancreatic islets, we investigated whether the molecule inhibits diabetogenic responses. Transfer of disease-inducing BDC2.5 T cells into B7x-deficient mice resulted in a more aggressive form of diabetes than in wild-type animals. This exacerbation of disease correlated with higher frequencies of islet-infiltrating Th1 and Th17 cells. Conversely, local B7x overexpression inhibited the development of autoimmunity, as crossing diabetes-susceptible BDC2.5/B6g7 mice to animals overexpressing B7x in pancreatic islets abrogated disease induction. This protection was caused by the inhibition of IFN-γ production by CD4 T cells and not to a skewing or expansion of Th2 or regulatory T cells. The suppressive function of B7x was also supported by observations from another autoimmune model, experimental autoimmune encephalomyelitis, in which B7x-deficient mice developed exacerbated disease in comparison with wild-type animals. Analysis of central nervous system–infiltrating immune cells revealed that the loss of endogenous B7x resulted in expanded Th1 and Th17 responses. Data from these two autoimmune models provide evidence that B7x expression in the periphery acts as an immune checkpoint to prevent tissue-specific autoimmunity.

Sign in / Sign up

Export Citation Format

Share Document