scholarly journals Evaluation of Thymic Output and Regulatory T Cells in Kidney Transplant Recipients with Chronic Antibody-Mediated Rejection

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Abbas Shahi ◽  
Saeedeh Salehi ◽  
Shima Afzali ◽  
Ladan Gol Mohammad Pour Afrakoti ◽  
Marzie Esmaeili ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
Graft Function ◽  
Treg Cells ◽  
Kidney Transplant Recipients ◽  
Transplant Tolerance ◽  
Thymic Output ◽  
Antibody Mediated Rejection

Background. Regulatory T cells (Tregs) and recent thymic emigrants (RTEs) have an essential role in the regulation of allogeneic immune responses. However, their mechanisms of action in chronic antibody-mediated rejection (cAMR) are still unclear. In this study, we aimed to compare Treg and RTE levels between stable graft function (SGF) patients and cAMR subjects after kidney transplantation. Method. Mononuclear cells (MNs) were separated from peripheral blood, and flow cytometry analysis was performed for detection of CD4+ and CD25high as Treg markers and CD4+, CD31+, and CD45RA+ as RTE immunophenotyping markers. Result. The level of peripheral Treg cells was significantly lower in cAMR subjects in comparison to stable graft function patients. Moreover, SGF patients who had received cyclosporine A had a higher level of Treg in comparison to the tacrolimus recipients. Nevertheless, the RTE level between SGF and cAMR patients did not show any significant differences. Conclusion. It seems that Treg cells are significantly associated with transplant outcomes in cAMR patients, and prescribed immunosuppressive drugs can influence the frequency of this crucial subset of T cells. Although these drugs are beneficial and inevitable for allograft maintenance, more investigations are needed to elucidate their complete effects on different immune cell subsets which some of them like Tregs are in favor of transplant tolerance. Besides, the thymic output is seemingly not a beneficial biomarker for predicting cAMR; however, more in vivo and in vitro studies are needed for revealing the precise role of Tregs and RTEs in the transplantation context.

scholarly journals Precision engineering of an anti-HLA-A2 chimeric antigen receptor in regulatory T cells for transplant immune tolerance

2021 ◽  
Author(s):  
Yannick D. Muller ◽  
Leonardo M.R. Ferreira ◽  
Emilie Ronin ◽  
Patrick Ho ◽  
Vinh Nguyen ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Chimeric Antigen Receptor ◽  
Mononuclear Cells ◽  
Antigen Receptor ◽  
Single Chain ◽  
Transplant Tolerance ◽  
Peripheral Blood Mononuclear

Infusion of regulatory T cells (Tregs) engineered with a chimeric antigen receptor (CAR) targeting donor-derived human leukocyte antigen (HLA) is a promising strategy to promote transplant tolerance. Here, we describe an anti-HLA-A2 CAR (A2-CAR) generated by grafting the complementarity-determining regions (CDRs) of a human monoclonal anti-HLA-A2 antibody into the framework regions of the Herceptin 4D5 single-chain variable fragment and fusing it with a CD28-zeta signaling domain. The CDR-grafted A2-CAR maintained the specificity of the original antibody. We then generated HLA-A2 mono-specific human CAR Tregs either by deleting the endogenous T-cell receptor (TCR) via CRISPR/Cas9 and introducing the A2-CAR using lentiviral transduction or by directly integrating the CAR construct into the TCR alpha constant locus using homology-directed repair. These A2-CAR+TCRdeficient human Tregs maintained both Treg phenotype and function in vitro. Moreover, they selectively accumulated in HLA-A2-expressing islets transplanted from either HLA-A2 transgenic mice or deceased human donors. A2-CAR+TCRdeficient Tregs did not impair the function of these HLA-A2+ islets, whereas similarly engineered A2-CAR+TCRdeficientCD4+ conventional T cells rejected the islets in less than 2 weeks. A2-CAR+TCRdeficient Tregs delayed graft-versus-host disease only in the presence of HLA-A2, expressed either by co-transferred peripheral blood mononuclear cells or by the recipient mice. Altogether, we demonstrate that genome-engineered mono-antigen-specific A2-CAR Tregs localize to HLA-A2-expressing grafts and exhibit antigen-dependent in vivo suppression, independent of TCR expression. These approaches may be applied towards developing precision Treg cell therapies for transplant tolerance.

Role of Regulatory T Cells in Infection and Vaccination During Early Infancy

2018 ◽  
Vol 24 (30) ◽  
pp. 3495-3505
Author(s):  
Samanta C. Funes ◽  
Miguel A. Mansilla ◽  
Gisela Canedo-Marroquín ◽  
Margarita K. Lay ◽  
Claudia A. Riedel ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Cell Function ◽  
Immune Cell ◽  
Active Role ◽  
Treg Cells ◽  
Health Goals ◽  
Inhibitory Mechanisms ◽  
Neonates And Infants

Reducing infant mortality due to infectious diseases is one of the most important public health goals worldwide. Several approaches have been implemented to reach this goal and vaccination has been an effective strategy for reducing infant and newborn mortality. However, the immunological features of neonates and infants represent a significant barrier to the effectiveness of vaccination. Since regulatory T cells (Treg cells) are known to play an active role in contributing to various mechanisms of suppression of the immune cell function. It has been proposed that these immune cells could decrease the immunogenicity of vaccines administered in newborns and infants. In this article, we discuss the various types of Treg cells, along with their suppressing and inhibitory mechanisms, which are used by these cells in the context of infectious and immunization processes in newborns and infants.

scholarly journals AB1068 REGULATORY EFFECT OF SHORT-TERM LOW DOSE OF IL-2 RESTORES REGULATORY T CELLS IN IgG4-RELATED DISEASE

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1823.2-1823
Author(s):  
Y. Wu ◽  
X. C. Zhao ◽  
J. Luo
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Low Dose ◽  
Immune Cell ◽  
Interleukin 2 ◽  
Treg Cells ◽  
T Cell Subsets ◽  
Related Disease ◽  
Igg4 Related Disease ◽  
The Absolute

Background:Little known about the roles of peripheral immune cell subsets in IgG4-related disease (IgG4-RD).Objectives:The aim of our study was to analyze the role of low-dose interleukin-2 (ld-IL2) on these cells in IgG4-RD.Methods:The percentage and absolute counts of lymphocyte subpopulations [CD3+ (T cells), CD4+, CD8+, CD19+ (B cells) and CD16+CD56+ (NK cells)] and CD4+T cell subsets (Th1, Th2, Th17, regulatory T (Treg)) using single platform flow cytometry in 25 IgG4-RD patients which were admitted and treated, as well as 24 healthy controls (HCs). Among IgG4-RD patients, 19 patients given only conventional treatments while 5 patients were were not only given conventional treatments but also received ld-IL2 (0.5 million IU/day) for 5 days.Results:We found that the absolute counts of T, CD4+T and Th1 cells were increased in the peripheral immune cells of IgG4-RD patients when compared with HCs. Meanwhile, the percentage of B, Th2, Th17 and Treg cells demonstrated significantly decreased. The ratio of Th1/Th2 and Th1/Treg in IgG4-RD patients were higher than that in HCs. After IL-2 administration, the absolute numbers of Treg cells increased dramatically, furthermore, the proportion of Treg cells had a trend towards higher values compared with those before treatment. Conversely, the ratio of Th2/Treg was downward. There were no any significant differences in the above subsets between before and after conventional treatments.Conclusion:Our findings support that the reduction of Treg cells in IgG4-RD patients, as well as ld-IL2 combined with conventional treatments were able to restore the Treg cells.References:[1]Akiyama M, Sasaki T, Kaneko Y, et al. Serum soluble interleukin-2 receptor is a useful biomarker for disease activity but not for differential diagnosis in IgG4-related disease and primary Sjögren’s syndrome adults from a defined population. Clin Exp Rheumatol, 2018.[2]Zhang SX, Wang J, Sun HH et al. Circulating regulatory T cells were absolutely decreased in dermatomyositis/polymyositis patients and restored by low-dose IL-2. Ann Rheum Dis, 2019.Disclosure of Interests:None declared

scholarly journals Ablation of interaction between IL-33 and ST2+ regulatory T cells increases immune cell-mediated hepatitis and activated NK cell liver infiltration

2016 ◽  
Vol 311 (2) ◽  
pp. G313-G323 ◽  
Author(s):  
Gregory Noel ◽  
Muhammad Imran Arshad ◽  
Aveline Filliol ◽  
Valentine Genet ◽  
Michel Rauch ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Nk Cells ◽  
Immune Cell ◽  
Nk Cell ◽  
Treg Cells ◽  
Protective Role ◽  
Con A ◽  
Membrane Expression

The IL-33/ST2 axis plays a protective role in T-cell-mediated hepatitis, but little is known about the functional impact of endogenous IL-33 on liver immunopathology. We used IL-33-deficient mice to investigate the functional effect of endogenous IL-33 in concanavalin A (Con A)-hepatitis. IL-33−/− mice displayed more severe Con A liver injury than wild-type (WT) mice, consistent with a hepatoprotective effect of IL-33. The more severe hepatic injury in IL-33−/− mice was associated with significantly higher levels of TNF-α and IL-1β and a larger number of NK cells infiltrating the liver. The expression of Th2 cytokines (IL-4, IL-10) and IL-17 was not significantly varied between WT and IL-33−/− mice following Con A-hepatitis. The percentage of CD25+ NK cells was significantly higher in the livers of IL-33−/− mice than in WT mice in association with upregulated expression of CXCR3 in the liver. Regulatory T cells (Treg cells) strongly infiltrated the liver in both WT and IL-33−/− mice, but Con A treatment increased their membrane expression of ST2 and CD25 only in WT mice. In vitro, IL-33 had a significant survival effect, increasing the total number of splenocytes, including B cells, CD4+ and CD8+ T cells, and the frequency of ST2+ Treg cells. In conclusion, IL-33 acts as a potent immune modulator protecting the liver through activation of ST2+ Treg cells and control of NK cells.

scholarly journals Precision Engineering of an Anti-HLA-A2 Chimeric Antigen Receptor in Regulatory T Cells for Transplant Immune Tolerance

2021 ◽  
Vol 12 ◽  
Author(s):  
Yannick D. Muller ◽  
Leonardo M. R. Ferreira ◽  
Emilie Ronin ◽  
Patrick Ho ◽  
Vinh Nguyen ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Chimeric Antigen Receptor ◽  
Mononuclear Cells ◽  
Antigen Receptor ◽  
Single Chain ◽  
Transplant Tolerance ◽  
Peripheral Blood Mononuclear

Infusion of regulatory T cells (Tregs) engineered with a chimeric antigen receptor (CAR) targeting donor-derived human leukocyte antigen (HLA) is a promising strategy to promote transplant tolerance. Here, we describe an anti-HLA-A2 CAR (A2-CAR) generated by grafting the complementarity-determining regions (CDRs) of a human monoclonal anti-HLA-A2 antibody into the framework regions of the Herceptin 4D5 single-chain variable fragment and fusing it with a CD28-ζ signaling domain. The CDR-grafted A2-CAR maintained the specificity of the original antibody. We then generated HLA-A2 mono-specific human CAR Tregs either by deleting the endogenous T-cell receptor (TCR) via CRISPR/Cas9 and introducing the A2-CAR using lentiviral transduction or by directly integrating the CAR construct into the TCR alpha constant locus using homology-directed repair. These A2-CAR+TCRdeficient human Tregs maintained both Treg phenotype and function in vitro. Moreover, they selectively accumulated in HLA-A2-expressing islets transplanted from either HLA-A2 transgenic mice or deceased human donors. A2-CAR+TCRdeficient Tregs did not impair the function of these HLA-A2+ islets, whereas similarly engineered A2-CAR+TCRdeficientCD4+ conventional T cells rejected the islets in less than 2 weeks. A2-CAR+TCRdeficient Tregs delayed graft-versus-host disease only in the presence of HLA-A2, expressed either by co-transferred peripheral blood mononuclear cells or by the recipient mice. Altogether, we demonstrate that genome-engineered mono-antigen-specific A2-CAR Tregs localize to HLA-A2-expressing grafts and exhibit antigen-dependent in vivo suppression, independent of TCR expression. These approaches may be applied towards developing precision Treg cell therapies for transplant tolerance.

scholarly journals Alterations in regulatory T cells and immune checkpoint molecules in pancreatic cancer patients receiving FOLFIRINOX or gemcitabine plus nab-paclitaxel

2021 ◽  
Author(s):  
L. Sams ◽  
S. Kruger ◽  
V. Heinemann ◽  
D. Bararia ◽  
S. Haebe ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Cd8 T Cells ◽  
Mononuclear Cells ◽  
Progression Free Survival ◽  
Ductal Adenocarcinoma ◽  
Immune Checkpoints ◽  
Prognostic Information ◽  
Peripheral Blood Mononuclear

Abstract Purpose This pilot study aimed on generating insight on alterations in circulating immune cells during the use of FOLFIRINOX and gemcitabine/nab-paclitaxel in pancreatic ductal adenocarcinoma (PDAC). Patients and methods Peripheral blood mononuclear cells were isolated before and 30 days after initiation of chemotherapy from 20 patients with advanced PDAC. Regulatory T cells (FoxP3+) and immune checkpoints (PD-1 and TIM-3) were analyzed by flow cytometry and immunological changes were correlated with clinical outcome. Results Heterogeneous changes during chemotherapy were observed in circulating T-cell subpopulations with a pronounced effect on PD-1+ CD4+/CD8+ T cells. An increase in FoxP3+ or PD-1+ T cells had no significant effect on survival. An increase in TIM3+/CD8+ (but not TIM3+/CD4+) T cells was associated with a significant inferior outcome: median progression-free survival in the subgroup with an increase of TIM-3+/CD8+ T cells was 6.0 compared to 14.0 months in patients with a decrease/no change (p = 0.026); corresponding median overall survival was 13.0 and 20.0 months (p = 0.011), respectively. Conclusions Chemotherapy with FOLFIRNOX or gemcitabine/nab-paclitaxel induces variable changes in circulating T-cell populations that may provide prognostic information in PDAC.

scholarly journals Regulatory T Cells Fail to Suppress Fast Homeostatic Proliferation In Vitro

Life ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 245
Author(s):  
Daniil Shevyrev ◽  
Valeriy Tereshchenko ◽  
Elena Blinova ◽  
Nadezda Knauer ◽  
Ekaterina Pashkina ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Autoimmune Diseases ◽  
Peripheral Blood ◽  
Treg Cells ◽  
Homeostatic Proliferation ◽  
Suppressive Activity ◽  
Healthy Donors

Homeostatic proliferation (HP) is a physiological process that reconstitutes the T cell pool after lymphopenia involving Interleukin-7 and 15 (IL-7 and IL-15), which are the key cytokines regulating the process. However, there is no evidence that these cytokines influence the function of regulatory T cells (Tregs). Since lymphopenia often accompanies autoimmune diseases, we decided to study the functional activity of Tregs stimulated by HP cytokines from patients with rheumatoid arthritis as compared with that of those from healthy donors. Since T cell receptor (TCR) signal strength determines the intensity of HP, we imitated slow HP using IL-7 or IL-15 and fast HP using a combination of IL-7 or IL-15 with anti-CD3 antibodies, cultivating Treg cells with peripheral blood mononuclear cells (PBMCs) at a 1:1 ratio. We used peripheral blood from 14 patients with rheumatoid arthritis and 18 healthy volunteers. We also used anti-CD3 and anti-CD3 + IL-2 stimulation as controls. The suppressive activity of Treg cells was evaluated in each case by the inhibition of the proliferation of CD4+ and CD8+ cells. The phenotype and proliferation of purified CD3+CD4+CD25+CD127lo cells were assessed by flow cytometry. The suppressive activity of the total pool of Tregs did not differ between the rheumatoid arthritis and healthy donors; however, it significantly decreased in conditions close to fast HP when the influence of HP cytokines was accompanied by anti-CD3 stimulation. The Treg proliferation caused by HP cytokines was lower in the rheumatoid arthritis (RA) patients than in the healthy individuals. The revealed decrease in Treg suppressive activity could impact the TCR landscape during lymphopenia and lead to the proliferation of potentially self-reactive T cell clones that are able to receive relatively strong TCR signals. This may be another explanation as to why lymphopenia is associated with the development of autoimmune diseases. The revealed decrease in Treg proliferation under IL-7 and IL-15 exposure can lead to a delay in Treg pool reconstitution in patients with rheumatoid arthritis in the case of lymphopenia.

scholarly journals B-cell activating factor BAFF as a novel alert marker for the immunological risk stratification after kidney transplantation

2021 ◽  
Author(s):  
Antonia Margarete Schuster ◽  
N. Miesgang ◽  
L. Steines ◽  
C. Bach ◽  
B. Banas ◽  
...  
Keyword(s):  
Kidney Transplantation ◽  
B Cell ◽  
Graft Function ◽  
Risk Profile ◽  
Kidney Transplant Recipients ◽  
Post Transplantation ◽  
Antibody Mediated Rejection ◽  
B Cell Activating Factor ◽  
Medium Risk ◽  
Patients At Risk

AbstractThe B cell activating factor BAFF has gained importance in the context of kidney transplantation due to its role in B cell survival. Studies have shown that BAFF correlates with an increased incidence of antibody-mediated rejection and the development of donor-specific antibodies. In this study, we analyzed a defined cohort of kidney transplant recipients who were treated with standardized immunosuppressive regimens according to their immunological risk profile. The aim was to add BAFF as an awareness marker in the course after transplantation to consider patient’s individual immunological risk profile. Included patients were transplanted between 2016 and 2018. Baseline data, graft function, the occurrence of rejection episodes, signs of microvascular infiltration, and DSA kinetics were recorded over 3 years. BAFF levels were determined 14 d, 3 and 12 months post transplantation. Although no difference in graft function could be observed, medium-risk patients showed a clear dynamic in their BAFF levels with low levels shortly after transplantation and an increase in values of 123% over the course of 1 year. Patients with high BAFF values were more susceptible to rejection, especially antibody-mediated rejection and displayed intensified microvascular inflammation; the combination of high BAFF + DSA puts patients at risk. The changing BAFF kinetics of the medium risk group as well as the increased occurrence of rejections at high BAFF values enables BAFF to be seen as an awareness factor. To compensate the changing immunological risk, a switch from a weaker induction therapy to an intensified maintenance therapy is required.

scholarly journals Secretome screening reveals immunomodulating functions of IFNα-7, PAP and GDF-7 on regulatory T-cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mei Ding ◽  
Rajneesh Malhotra ◽  
Tomas Ottosson ◽  
Magnus Lundqvist ◽  
Aman Mebrahtu ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Cell Function ◽  
Foxp3 Expression ◽  
Treg Cells ◽  
Secreted Proteins ◽  
External Stimulation ◽  
Marker Proteins ◽  
Positive Regulators ◽  
Conformational Model

AbstractRegulatory T cells (Tregs) are the key cells regulating peripheral autoreactive T lymphocytes. Tregs exert their function by suppressing effector T cells. Tregs have been shown to play essential roles in the control of a variety of physiological and pathological immune responses. However, Tregs are unstable and can lose the expression of FOXP3 and suppressive functions as a consequence of outer stimuli. Available literature suggests that secreted proteins regulate Treg functional states, such as differentiation, proliferation and suppressive function. Identification of secreted proteins that affect Treg cell function are highly interesting for both therapeutic and diagnostic purposes in either hyperactive or immunosuppressed populations. Here, we report a phenotypic screening of a human secretome library in human Treg cells utilising a high throughput flow cytometry technology. Screening a library of 575 secreted proteins allowed us to identify proteins stabilising or destabilising the Treg phenotype as suggested by changes in expression of Treg marker proteins FOXP3 and/or CTLA4. Four proteins including GDF-7, IL-10, PAP and IFNα-7 were identified as positive regulators that increased FOXP3 and/or CTLA4 expression. PAP is a phosphatase. A catalytic-dead version of the protein did not induce an increase in FOXP3 expression. Ten interferon proteins were identified as negative regulators that reduced the expression of both CTLA4 and FOXP3, without affecting cell viability. A transcriptomics analysis supported the differential effect on Tregs of IFNα-7 versus other IFNα proteins, indicating differences in JAK/STAT signaling. A conformational model experiment confirmed a tenfold reduction in IFNAR-mediated ISG transcription for IFNα-7 compared to IFNα-10. This further strengthened the theory of a shift in downstream messaging upon external stimulation. As a summary, we have identified four positive regulators of FOXP3 and/or CTLA4 expression. Further exploration of these Treg modulators and their method of action has the potential to aid the discovery of novel therapies for both autoimmune and infectious diseases as well as for cancer.

scholarly journals Endogenous retrovirus-encoded Syncytin-2 contributes to exosome-mediated immunosuppression of T cells†

2019 ◽  
Author(s):  
Adjimon G Lokossou ◽  
Caroline Toudic ◽  
Phuong Trang Nguyen ◽  
Xavier Elisseeff ◽  
Amandine Vargas ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell Activation ◽  
Map Kinases ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
Endogenous Retrovirus ◽  
Jurkat Cells ◽  
Peripheral Blood Mononuclear ◽  
Interfering Rna

Abstract Modulation of the activation status of immune cell populations during pregnancy depends on placental villous cytotrophoblast (VCT) cells and the syncytiotrophoblast (STB). Failure in the establishment of this immunoregulatory function leads to pregnancy complications. Our laboratory has been studying Syncytin-2 (Syn-2), an endogenous retroviral protein expressed in placenta and on the surface of placental exosomes. This protein plays an important role not only in STB formation through its fusogenic properties, but also through its immunosuppressive domain (ISD). Considering that Syn-2 expression is importantly reduced in preeclamptic placentas, we were interested in addressing its possible immunoregulatory effects on T cells. Activated Jurkat T cells and peripheral blood mononuclear cells (PBMCs) were treated with monomeric or dimerized version of a control or a Syn-2 ISD peptide. Change in phosphorylation levels of ERK1/2 MAP kinases was selectively noted in Jurkat cells treated with the dimerized ISD peptide. Upon incubation with the dimerized Syn-2 ISD peptide, significant reduction in Th1 cytokine production was further demonstrated by ELISA and Human Th1/Th2 Panel Multi-Analyte Flow Assay. To determine if exosome-associated Syn-2 could also be immunosuppressive placental exosomes were incubated with activated Jurkat and PBMCs. Quantification of Th1 cytokines in the supernatants revealed severe reduction in T cell activation. Interestingly, exosomes from Syn-2-silenced VCT incubated with PBMCs were less suppressive when compared with exosome derived from VCT transfected with control small interfering RNA (siRNA). Our results suggest that Syn-2 is an important immune regulator both locally and systemically, via its association with placental exosomes.

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