scholarly journals Human Double-Negative Regulatory T Cells Modulate Effector Functions of Conventional T Cells By Selectively Blocking mTOR Signaling

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2410-2410
Author(s):  
Tabea Haug ◽  
Michael Aigner ◽  
Heiko Bruns ◽  
Moritz Peuser ◽  
Dorothea Gebhardt ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Regulatory T Cells ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
Mtor Signaling ◽  
Regulatory Function ◽  
Acid Uptake ◽  
Double Negative

Abstract Regulatory T cells play an important role in the maintenance of immune tolerance to self-antigens and are involved in modulating immune responses to promote resolution of inflammation. The population of TCRαβ+ CD4-/CD8- (double-negative, DN) T cells has attracted growing attention as a result of their potent immune regulatory function. In murine models, DN T cells were able to prevent rejection of allogeneic and xenogeneic organ grafts by effectively suppressing reactive T cells. In addition, DN T cells possess the capacity to resolve various inflammatory conditions, including graft-versus-host disease (GvHD) after allogeneic hematopoietic stem cell transplantation. Notably, first clinical studies in patients after stem cell transplantation demonstrated an inverse correlation between the frequency of circulating DN T cells and the severity of acute GvHD, suggesting a therapeutic potential of human DN T cells. To gain a better understanding of the molecular mechanism of suppression, we investigated whether human DN T cells modulate distinct signaling processes in conventional T cells. We found that DN T cells selectively block mTOR signaling but not activation of mitogen-activated protein kinases. Enforced activation of the mTOR pathway by a chemical activator rendered conventional T cells unsusceptible to DN T cell-mediated suppression, confirming the critical function of mTOR signaling. Given that mTOR is a major regulator of cellular metabolism, we further determined the impact of DN T cells on the metabolic framework of conventional T cells. Of interest, DN T cells diminished upregulation of the glycolytic machinery and glucose uptake in conventional T cells, whereas fatty acid uptake was not modified. Next, we investigated the fate and function of effector cells after DN T cell co-culture. Of importance, DN T cells suppressed proliferation but also altered expression of differentiation markers, transcription factors and homing receptors. Further analyses demonstrated that CD4+ T cells failed to produce effector cytokines IL-17 and IFN-γ after coculture with DN T cells, whereas IL-2 secretion was amplified. The selective modification was induced by a direct cell-cell contact dependent mechanism between CD4 and DN T cells and not as a consequence of competition for nutrients or growth factors. Together, our findings expand the understanding of DN T cell functionality and support that human DN T cells represent an interesting opportunity to limit and modulate T-cell reactivity. Disclosures No relevant conflicts of interest to declare.

Vaccination with DC/Multiple Myeloma Fusions in Conjunction with Stem Cell Transplantation.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 578-578
Author(s):  
David Avigan ◽  
Jacalyn Rosenblatt ◽  
Baldev Vasir ◽  
Zekui Wu ◽  
Adam Bissonnette ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Regulatory T Cells ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
Tumor Immunity ◽  
Myeloma Cells ◽  
Post Transplant

Abstract Autologous transplantation results in the transient reversal of tumor mediated tolerance due to the reduction in disease bulk, the depletion of regulatory T cells, and in the increased presence of tumor reactive lymphocytes during the period of lymphopoietic reconstitution. As a result, cancer vaccines are being explored as a means of targeting residual myeloma cells following stem cell transplant. We have developed a cancer vaccine in which patient derived tumor cells are fused with autologous dendritic cells (DCs). In this way multiple tumor antigens are presented in the context of DC mediated costimulation. We are conducting a study in which patients with multiple myeloma (MM) undergo stem cell transplantation followed by vaccination with 3 doses of DC/MM fusions. DCs were generated from adherent mononuclear cells cultured with GM-CSF and IL-4 for 5–7 days and matured with TNFa. DCs strongly expressed costimulatory and maturation markers. Myeloma cells were isolated from bone marrow aspirates and were identified by their expression of CD38, CD138, and/or MUC1. DC and MM cells were fused with polyethylene glycol as previously described and fusion cells were quantified by determining the percentage of cells that coexpress unique DC and myeloma antigens. To date, 19 patients have been enrolled and 18 have completed vaccine generation. Mean yield of the DC and myeloma preparations was 1.84 × 108 and 8.3 × 107 cells, respectively. Mean fusion efficiency was 40% and the mean cell dose was 4.3 × 106 fusion cells. As a measure of their potency as antigen presenting cells, fusion cells prominently stimulated allogeneic T cell proliferation in vitro. Mean stimulation indexes were 12, 57, and 31 for T cells stimulated by myeloma cells, DCs, and fusion cells, respectively. Adverse events judged to be potentially vaccine related included injection site reactions, pruritis, myalgias, fever, chills, and tachycardia. Six patients have completed the follow up period and 3 patients are currently undergoing vaccination. All patients achieved a partial response to transplant. Three patients demonstrated resolution of post-transplant paraprotein levels following vaccination. One patient with highly aggressive disease who experienced disease progression in the early post-transplant period, demonstrated initial response and then stabilization of disease with vaccination. We are examining the effect of transplant and vaccination on measures of cellular immunity, anti-tumor immunity and levels or activated as compared to regulatory T cells. T cell response to PHA mitogen was transiently depressed post-transplant. In contrast, a transient increase was noted post-transplant in mean T cell expression of IFNγ in response to autologous myeloma cell lysate. In preliminary studies, a relative increase in the ratio of activated (CD4/CD25low) to regulatory (CD4/CD25high) T cells was observed. To date, all evaluable patients demonstrated evidence of vaccine stimulated anti-tumor immunity as manifested by a rise in IFNγ expression by CD4 and/or CD8+ T cells following ex vivo exposure to autologous tumor lysate. In this ongoing study, fusion cell vaccination in conjunction with stem cell transplantation has been well tolerated, induced anti-tumor immunity and clinical responses in patients with multiple myeloma.

The CD4+CD25highregulatory T Cell Reconstitution after Allogenetic Stem Cell Transplantation and Its Correlations with aGVHD

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4360-4360
Author(s):  
Caixia Li ◽  
Wu Depei ◽  
Dao ping Sun ◽  
Yuejun Liu ◽  
Weirong Chang ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Regulatory T Cells ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
Peripheral Blood ◽  
Control Level ◽  
Foxp3 Mrna ◽  
Donor Graft

Abstract Background CD4+CD25+ regulatory T cell (Treg), the most significant subset of regulatory T cells, has been found to play an important role in suppressing allogenetic immune response and controlling GVHD recently. The present single-center study monitored the ratio of CD4+CD25high T cells and the expression of FOXP3 gene in peripheral blood post-transplant to assess the reconstitution of CD4+CD25high Treg early after allogenetic stem cell transplantation and its correlations with aGVHD. Methods: 22 patients undergoing allo-HSCT were enrolled. To detect the CD4+CD25+T cells and the CD4+CD25high T cells subpopulations ratio in CD4+ T lymphocytes(CD4+CD25+/CD4+ ACD4+CD25high/CD4+) Athe CD4+CD25high T cells subpopulations ratio in CD4+CD25+ T cells(CD4+CD25high/CD4+ CD25+) Aand the expression of FOXP3 mRNA in the donor graft and periperal blood frequently after transplantation with the flow cytometry and real-time PCR assays. Results: \|[Dagger]\|@CD4 +CD25high/CD4+ and CD4+CD25high/CD4+CD25+ ratios in the donor graft were significantly lower in the aGVHD group(P<0.05)‡AEarly after transplantation, Both groups’CD4+CD25+/CD4+ ratio in peripheral blood increased significantly than that in the donor graft(P<0.05).CD4+CD25high/CD4+ and CD4+CD25high/CD4+CD25+ ratios were also significantly higher than that in donor graft in the aGVHD group, but not in the no-aGVHD group.‡BThe expression of FOXP3 in two groups after transplantation increased gradually, until six months after transplantation, its expression was still below the control level(P<0.05). The expression of FOXP3 was lower in the aGVHD group. Conclusion: \|[Dagger]\|@The early activation and proliferation of the CD4+CD25high regulatory T cells is critical for the maintainance of immune hemostasis and the control of aGVHD.‡AThe occurrence of aGVHD is related with lower ratios of CD4+CD25high regulatory T cells in CD4+T cells and activated CD4+ effector T cells.‡BaGVHD may affect the quantities of CD4+CD25high regulatory T cells and the expression of FOXP3.

Fusion Cell Vaccination in Conjunction with Stem Cell Transplantation Is Well Tolerated, Induces Anti-Tumor Immunity and Is Associated with Responses in Patients with Multiple Myeloma

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 826-826 ◽  
Author(s):  
Davi D Avigan ◽  
Jacalyn Rosenblatt ◽  
Baldev Vasir ◽  
Zekui Wu ◽  
Adam Bissonnette ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Regulatory T Cells ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
Tumor Antigens ◽  
Myeloma Cells ◽  
Post Transplant ◽  
Fusion Cell

Abstract Autologous stem cell transplantation results in tumor cytoreduction and improved disease outcomes in patients with multiple myeloma (MM), but patients ultimately relapse from persistent disease. A promising area of investigation is the development of cancer vaccines that educate host immunity to target and eliminate myeloma cells and can be used to eradicate residual disease following autologous stem cell transplantation. The early post-transplant period is characterized by a transient reversal of tumor mediated tolerance due to the reduction in disease bulk, the depletion of regulatory T cells. We have developed a cancer vaccine model in which DCs are fused to autologous MM cells resulting in the presentation of multiple tumor antigens with the capacity to elicit a broad anti-tumor response. We are conducting a study in which patients with MM undergo stem cell transplantation followed by post-transplant vaccination with 3 doses of DC/MM fusions. DCs were generated from adherent mononuclear cells cultured with GM-CSF and IL-4 for 5–7 days and matured with TNFα. DCs strongly expressed costimulatory and maturation markers. Myeloma cells were isolated from bone marrow aspirates and were identified by their expression of CD38, CD138, and/or MUC1. DC and MM cells were fused with polyethylene glycol and fusion cells were quantified by determining the percentage of cells that coexpress unique DC and myeloma antigens. To date, 26 patients have been enrolled. All patients have undergone successful vaccine generation. Mean yield of the DC and myeloma preparations was 171×106 and 70×106 cells, respectively. Mean fusion efficiency was 40% and the mean cell dose generated was 4×106 fusion cells. Mean viability of the DC, myeloma, and fusion preparations was 88%, 86%, and 78%, respectively. As a measure of their potency as antigen presenting cells, fusion cells potently stimulated allogeneic T cell proliferation in vitro. Mean stimulation indexes were 12, 57, 31 for T cells stimulated by myeloma cells, DCs, and fusion cell preparations at an APC: T cell ratio of 1:10. Adverse events judged to be potentially vaccine related were mild, and included injection site reactions, pruritis, myalgias, fever, chills, headache, fatigue and tachycardia. To date 14 patients have completed vaccinations and initial follow up of which 8 have achieved a complete remission and 6 a partial remission. Of note, 4 patients achieved complete remission only after undergoing post-transplant vaccination. We are examining the effect of transplant and vaccination on measures of cellular immunity, antitumor immunity and levels of activated as compared to regulatory T cells. T cell responses to PHA mitogen and tetanus toxoid were transiently depressed post-transplant. Similarly, DTH responses to candida antigen were absent post-transplant in all but 1 patient. In contrast, a significant increase was noted post-transplant in circulating tumor reactive lymphocytes as determined by T cell expression of IFNγ by CD4 and CD8 cells following ex vivo coculture with autologous myeloma cell lysate (Mean percentage of tumor reactive CD8 cells was 0.9 and 11 pre and post-transplant, respectively p=0.01; mean percentage of CD4 cells was 0.7 and 2.7; p=0.02). A further amplification of tumor reactive lymphocytes was seen with vaccination in a subset of patients (mean percentage of CD4 and CD8 tumor reactive T cells was 4.9 and 15, respectively). A decrease in the median levels of circulating regulatory T cells and a relative increase in the ratio of activated (CD4/CD25low)/regulatory (CD4/CD25high) cells was observed following transplantation. This finding suggests that although nonspecific T cell responses are muted in the early posttransplant period, there is a greater capacity to recognize tumor antigens, potentially due to the depletion of regulatory T cells and the decline in tumor mediated immune suppression. In summary, fusion cell vaccination in conjunction with stem cell transplantation was well tolerated, induced anti-tumor immunity and clinical responses in patients with MM. The post-transplant period is characterized by increased levels of activated as compared to regulatory T cells and enhanced levels of T cells with the capacity to respond to myeloma cells. The increase in tumor reactive T cells post-transplant is further amplified following exposure to the DC/MM fusion vaccine.

Clinical Correlation of Foxp3 Regulatory Gene Expressions and NK Cells in Early Engraftment after Myeloablative Allogeneic Stem Cell Transplantation.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2911-2911
Author(s):  
Deok-Hwan Yang ◽  
Chung-Sun Park ◽  
Yeo-Kyeoung Kim ◽  
Je-Jung Lee ◽  
Hyeoung Joon Kim
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Regulatory T Cells ◽  
Stem Cell Transplantation ◽  
Nk Cells ◽  
Cell Transplantation ◽  
Nk Cell ◽  
Gene Expressions ◽  
Foxp3 Gene

Abstract Regulatory T cells (Tregs) have been established as a key role of self tolerance and preventing proliferation of auto- and alloantigen-reactive T cells. CD4+CD25+ Tregs suppress GVHD in animal models, but in human data on GVHD following stem cell transplantation (SCT) is conflicting. We postulate that CD4+Foxp3+Tregs not only reduce the incidence of acute graft-versus host disease (aGVHD) but inhibit the NK cell functions in patients who received allogeneic SCT. CD4+Foxp3+Tregs also may adversely affect the GVL effect and cause the relapse of disease. Patients and Methods: 25 patients (AML:13, ALL:9, CML:2, NHL:1) were undergone allogeneic SCT. Nine patients were infused from unrelated donor and five patients were from HLA one-mismatch. Three patients added alemtuzumab to myeloablative conditioning regimen due to HLA mismatch. Peripheral blood mononuclear cell (PBMC) were separated 3 or 4 weeks after SCT when absolute neutrophil count reached above 1000 × 109/L. NK cells were phenotypically analyzed by flow cytometry using directly conjugated antibodies to CD3 and CD56. CD4+ cells were isolated from PBMC using micro-bead (MACS) and the expression levels of Foxp3 mRNA were assessed by quantitative real-time PCR. Results: 12 patients developed grade 2–4 acute GVHD and 10 patients relapsed. Patients who experienced Gr2-4 aGVHD had significantly lower the relapse rate than those who Gr0-1 aGVHD (P=0.002). Foxp3 gene expressions within CD4+ T cells were significantly lower in Gr2-4 aGVHD patients (median, 4.278 ng/μl) than in Gr0-1 aGVHD patients (median 7.914 ng/μl) except three patients treated with alemtuzumab conditioning (P=0.016). All of three patients used alemtuzumab experienced the relapse and no aGVHD. They also had very lower Foxp3 gene expressions (median, 4.760 ng/μl) than those in Gr0-1 aGVHD patients. Without alemtuzumab used patients, the levels of Foxp3 expression in relapsed patients were significantly higher than those in non-relapsed patients (median, 11.684 ng/μl and 2.031 ng/μl, respectively) (P=0.001). However, we could not find an inverse correlation between NK cell expressions and CD4+Foxp3+Tregs and a positive correlation between infused T cell doses and CD4+Foxp3+Tregs expression. Conclusion: The levels of CD4+Foxp3+Tregs affect the incidence of aGVHD and predict the risk of the relapse. Alemtuzumab may influence the T cell recovery including regulatory T cells after early post-SCT.

scholarly journals Autologous stem cell transplantation aids autoimmune patients by functional renewal and TCR diversification of regulatory T cells

Blood ◽  
2016 ◽  
Vol 127 (1) ◽  
pp. 91-101 ◽  
Author(s):  
Eveline M. Delemarre ◽  
Theo van den Broek ◽  
Gerdien Mijnheer ◽  
Jenny Meerding ◽  
Ellen J. Wehrens ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Regulatory T Cells ◽  
Stem Cell Transplantation ◽  
Clinical Improvement ◽  
Autologous Stem Cell Transplantation ◽  
T Cell Reconstitution ◽  
Key Points ◽  
Autologous Hsct

Key Points Autologous HSCT induces functional renewal of regulatory T cells as well as a strong Treg TCR diversification in autoimmune patients. Adding regulatory T cells to the graft does not lead to additional clinical improvement but results in delayed donor T-cell reconstitution.

scholarly journals Early Reconstitution of Antibody Secreting Cells after Allogeneic Stem Cell Transplantation

2022 ◽  
Vol 11 (1) ◽  
pp. 270
Author(s):  
Martina Hinterleitner ◽  
Clemens Hinterleitner ◽  
Elke Malenke ◽  
Birgit Federmann ◽  
Ursula Holzer ◽  
...  
Keyword(s):  
Innate Immunity ◽  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
B Cells ◽  
Stem Cell Transplantation ◽  
B Cell ◽  
Cell Transplantation ◽  
Antibody Secreting Cells

Immune cell reconstitution after stem cell transplantation is allocated over several stages. Whereas cells mediating innate immunity recover rapidly, adaptive immune cells, including T and B cells, recover slowly over several months. In this study we investigated kinetics and reconstitution of de novo B cell formation in patients receiving CD3 and CD19 depleted haploidentical stem cell transplantation with additional in vivo T cell depletion with monoclonal anti-CD3 antibody. This model enables a detailed in vivo evaluation of hierarchy and attribution of defined lymphocyte populations without skewing by mTOR- or NFAT-inhibitors. As expected CD3+ T cells and their subsets had delayed reconstitution (<100 cells/μL at day +90). Well defined CD19+ B lymphocytes of naïve and memory phenotype were detected at day +60. Remarkably, we observed a very early reconstitution of antibody-secreting cells (ASC) at day +14. These ASC carried the HLA-haplotype of the donor and secreted the isotypes IgM and IgA more prevalent than IgG. They correlated with a population of CD19− CD27− CD38low/+ CD138− cells. Of note, reconstitution of this ASC occurred without detectable circulating T cells and before increase of BAFF or other B cell stimulating factors. In summary, we describe a rapid reconstitution of peripheral blood ASC after CD3 and CD19 depleted haploidentical stem cell transplantation, far preceding detection of naïve and memory type B cells. Incidence before T cell reconstitution and spontaneous secretion of immunoglobulins allocate these early ASC to innate immunity, eventually maintaining natural antibody levels.

New Developments in Allotransplant Immunology

Hematology ◽  
2003 ◽  
Vol 2003 (1) ◽  
pp. 350-371 ◽  
Author(s):  
A. John Barrett ◽  
Katayoun Rezvani ◽  
Scott Solomon ◽  
Anne M. Dickinson ◽  
Xiao N. Wang ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
Immune Reconstitution ◽  
Cytokine Gene ◽  
Post Transplant ◽  
Cytokine Milieu ◽  
Cytokine Gene Polymorphisms

Abstract After allogeneic stem cell transplantation, the establishment of the donor’s immune system in an antigenically distinct recipient confers a therapeutic graft-versus-malignancy effect, but also causes graft-versus-host disease (GVHD) and protracted immune dysfunction. In the last decade, a molecular-level description of alloimmune interactions and the process of immune recovery leading to tolerance has emerged. Here, new developments in understanding alloresponses, genetic factors that modify them, and strategies to control immune reconstitution are described. In Section I, Dr. John Barrett and colleagues describe the cellular and molecular basis of the alloresponse and the mechanisms underlying the three major outcomes of engraftment, GVHD and the graft-versus-leukemia (GVL) effect. Increasing knowledge of leukemia-restricted antigens suggests ways to separate GVHD and GVL. Recent findings highlight a central role of hematopoietic-derived antigen-presenting cells in the initiation of GVHD and distinct properties of natural killer (NK) cell alloreactivity in engraftment and GVL that are of therapeutic importance. Finally, a detailed map of cellular immune recovery post-transplant is emerging which highlights the importance of post-thymic lymphocytes in determining outcome in the critical first few months following stem cell transplantation. Factors that modify immune reconstitution include immunosuppression, GVHD, the cytokine milieu and poorly-defined homeostatic mechanisms which encourage irregular T cell expansions driven by immunodominant T cell–antigen interactions. In Section II, Prof. Anne Dickinson and colleagues describe genetic polymorphisms outside the human leukocyte antigen (HLA) system that determine the nature of immune reconstitution after allogeneic stem cell transplantation (SCT) and thereby affect transplant outcomethrough GVHD, GVL, and transplant-related mortality. Polymorphisms in cytokine gene promotors and other less characterized genes affect the cytokine milieu of the recipient and the immune reactivity of the donor. Some cytokine gene polymorphisms are significantly associated with transplant outcome. Other non-HLA genes strongly affecting alloresponses code for minor histocompatibility antigens (mHA). Differences between donor and recipient mHA cause GVHD or GVL reactions or graft rejection. Both cytokine gene polymorphisms (CGP) and mHA differences resulting on donor-recipient incompatibilities can be jointly assessed in the skin explant assay as a functional way to select the most suitable donor or the best transplant approach for the recipient. In Section III, Dr. Nelson Chao describes non-pharmaceutical techniques to control immune reconstitution post-transplant. T cells stimulated by host alloantigens can be distinguished from resting T cells by the expression of a variety of activation markers (IL-2 receptor, FAS, CD69, CD71) and by an increased photosensitivity to rhodamine dyes. These differences form the basis for eliminating GVHD-reactive T cells in vitro while conserving GVL and anti-viral immunity. Other attempts to control immune reactions post-transplant include the insertion of suicide genes into the transplanted T cells for effective termination of GVHD reactions, the removal of CD62 ligand expressing cells, and the modulation of T cell reactivity by favoring Th2, Tc2 lymphocyte subset expansion. These technologies could eliminate GVHD while preserving T cell responses to leukemia and reactivating viruses.

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