Damage-Induced Pyroptotic Cell Death Facilitates Regeneration of the Thymus

T cell reconstitution after transplant is critically dependent on the thymus; an inverse relationship between a transplant recipient's age and their capacity to generate T lymphocytes (in particular CD4+T cells) has been found in several studies, and thymic function pre-transplant can have a significant impact on clinical outcomes. Although the thymus has a remarkable ability to repair following damage, the mechanisms underlying this endogenous regeneration remain poorly understood. Despite this regenerative capacity, delayed T cell reconstitution is associated with an increased risk of infections, relapse of malignancy and the development of secondary malignancies. Therefore, there is a clinical demand for therapeutics that restore immune function after damage. Our recent studies have identified two key pathways driving thymic regeneration; centered on the secretion of BMP4 by endothelial cells (ECs) and IL-22 by innate lymphoid cells (Dudakov 2012 Science 336:91; Dudakov 2017 Blood130:933; Wertheimer 2018 Sci Immunol3:19). However, the specific regulatory mechanisms that trigger these regeneration-associated factors after damage remain unclear. Our previous work identified that the presence of homeostatic apoptotic CD4+CD8+ (DP) thymocytes, as apoptotic thymocytes form the bulk of developing T cells, suppress the production of IL-23 in dendritic cells (DCs), a key downstream mediator for IL-22, and BMP4 in ECs (Fig. 1A), and that the depletion of apoptotic thymocytes after damage precedes the production of these regenerative factors. Therefore, together with our findings that the metabolic needs of key thymus populations alter drastically following injury due to damage-induced metabolic remodeling, we hypothesized that further to the loss of DP-specific suppression, metabolic dysfunction in DPs after damage triggers mitochondrial-induced pyroptotic cell death, which can directly promote regeneration of the thymus. Consistent with this hypothesis, our preliminary data shows increased levels of cl-caspase 1 (pyroptotic caspase) and a decrease in cl-caspase 3 (apoptotic caspase) in DPs after SL-TBI (550 cGy), demonstrating a preferential induction of pyroptotic cell death in DPs after damage (Fig. 1B). Furthermore, we demonstrated an increase in extracellular lactate dehydrogenase (LDH) levels, HMGB-1 and TNF⍺[canonical damage-associated molecular patterns (DAMPs) released during ICD] acutely after damage caused by SL-TBI (Fig. 1C).Given our previous findings that stromal cells are more radio-resistant than DP thymocytes (Wertheimer 2018 Sci Immunol3:19), and evidence for mitochondrial-induced pyroptosis, we identified hyperpolarization of the mitochondrial membrane potential accompanied by increased levels of ROS in DPs, an effect not observed in TECs, suggesting metabolic stability confers protection against acute damage (Fig. 1D). Furthermore, co-culture of pyroptotic thymocytes results in increased IL12p40+ DCs and increased Foxn1 expression in TECs (Fig. 1E), strengthening our hypothesis that cell-cell communication drives thymic regeneration after damage by inducing regenerative factors as well as directly promoting TEC function via secreted factors from pyroptotic DPs. One way in which DAMPs, such as ATP, can initiate cell signaling is by the activation of cell surface purinergic receptors, including P2Y2 which is widely expressed on TECs, and here we demonstrate that in vitro treatment with ATP or P2Y2 agonist increases Foxn1 in cTECs, and P2Y2 antagonism reverses this effect (Fig 1F). As P2Y2 activation promotes Ca2+efflux from the ER, we have further demonstrated that stimulating the intracellular release of Ca2+, using tunicamycin, induced Foxn1 expression in cTECs, which was reversed upon inhibition of Ca2+release (Fig. 1G). Importantly, we demonstrate here that this pathway can be therapeutically targeted by activating P2Y2 signaling in vivo with MRS2568 or ATP enhances thymus cellularity and expands cTECs in models of acute injury (Fig. 1H&I). These findings not only reveal a novel metabolic-mediated molecular mechanism governing tissue regeneration; but also by targeting FOXN1 directly offers a potentially superior therapeutic strategy for boosting thymic regeneration and T cell reconstitution after damage such as that caused by HCT, infection or cytoreductive therapy. Disclosures No relevant conflicts of interest to declare.

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Zinc Treatment Stimulates Thymic Regeneration after Bone Marrow Transplant

Blood ◽

10.1182/blood-2019-129290 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 4422-4422

Author(s):

Lorenzo Iovino ◽

Sinéad Kinsella ◽

Kirsten Cooper ◽

Reema Jain ◽

Paul DeRoos ◽

...

Keyword(s):

T Cell ◽

Zinc Supplementation ◽

Conflicts Of Interest ◽

The Body ◽

Acute Injury ◽

Thymic Epithelial Cells ◽

Steady Increase ◽

Cell Transplant ◽

Hematopoietic Stem ◽

Thymic Regeneration

Prolonged T cell reconstitution after allogeneic hematopoietic stem cell transplant (allo-HSCT) is an important contributor to transplant-related morbidity and mortality due to infection and malignant relapse. Therefore, strategies to enhance thymic reconstitution in allo-HSCT recipients are clinically desirable, although currently limited. Zinc, the second most abundant trace metal in the body, plays an important role in T cell homeostasis and thymic function. In a mouse model of allo-HSCT (Fig. a), we demonstrated that zinc supplementation can significantly improve thymic regeneration (Fig. b). Importantly, these findings in thymus were translated to the periphery as mice that received zinc supplementation showed increased numbers of naïve T cells as well as increased recent thymic emigrants (demonstrated using RAG2-GFP BM donors) model (Fig. c-d) 5-8 weeks after allo-HSCT. We have previously demonstrated that endothelial cells (EC), which are extremely resistant to damage, can promote endogenous thymic regeneration after acute injury via their production of BMP4, a growth factor that targets thymic epithelial cells (TECs), a key population crucial for T cell development. Interestingly, when stimulated in vitro for 24 hours with zinc sulphate, ECs could be directly induced to produce BMP4, but not when exposed to increased zinc import with the cell-permeable zinc pyrithione (Fig. e). This latter finding suggests a role for extracellular zinc in stimulating the endogenous response to damage. To explore this, we first measured the content of zinc in whole mouse thymus by mass spectrometry. Interestingly, when we examined a lysate of the entire thymus, total zinc concentration sharply declined early after total body radiation (TBI), followed by a steady increase that mirrored the reconstitution of the thymic cellularity (Fig. f). However, if we looked at zinc in the extracellular fraction of thymic dissociation (referred to as supernatants, SN), we saw that zinc increased significantly after TBI, revealing an inverse correlation with thymic cellularity (Fig. g), and providing a rationale for how zinc might contribute to the endogenous regenerative response. Given these findings, we hypothesized that zinc is normally used and stored in the T-cell precursors, a population of highly-replicating cells that account for approximately 98% of thymic cellularity in young mice and require the import of intracellular zinc for their proliferation. T-cell precursors are radio-sensitive and might release zinc in the extracellular space after cell death due to TBI, thereby triggering the production of regenerating factors from radio resistant cells, such as EC. Zinc supplementation could help this loop by increasing endogenous zinc levels. This hypothesis was confirmed when we co-cultured EC in presence of thymic SN there was no difference in BMP4 expression in cocultures with SN from control and zinc-treated mice at day 0, whereas BMP4 increased in presence of SN harvested from mice that had previously received TBI and even more when mice also received zinc supplement (Fig h). In conclusion, our findings demonstrate that zinc supplementation can improve T-cell regeneration in mice receiving allo-HSCT by reinforcing endogenous mechanisms of thymic regeneration. These results could be readily clinically translated into better outcomes for recipients of allo-HCT. Figure Disclosures No relevant conflicts of interest to declare.

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Adverse Events Following Infusion of T Cells for Adoptive Immunotherapy: A 10 Year Experience.

Blood ◽

10.1182/blood.v114.22.3212.3212 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3212-3212

Author(s):

Conrad Russell Y. Cruz ◽

Patrick Hanley ◽

Hao Liu ◽

Vicky Torrano ◽

Yu-Feng Lin ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Adverse Events ◽

Conflicts Of Interest ◽

Ex Vivo ◽

Safe Procedure ◽

Cell Product ◽

Increased Risk ◽

Infusion Reactions ◽

Severe Adverse Events

Abstract Abstract 3212 Poster Board III-149 Following administration of ex-vivo expanded T cells, the FDA currently recommends at least 4 hours of recipient monitoring to detect early infusion reactions. Recent catastrophic reactions to “first in man” biological agents have emphasized the importance of this rule for initial studies of new products, but its value for longer established agents is less evident. We have therefore reviewed the incidence and nature of infusion-related adverse events (AEs) associated with administration of ex-vivo expanded T cell products (antigen specific CTLs, allodepleted T cells, and genetically modified T cells) on Investigational New Drug (IND) studies in our center over the last decade. From 1998 to 2008, we infused 381 T cell products to 180 recipients who were enrolled on 18 such studies, receiving T cells targeting malignancies or post-transplant viral infections. The age of these recipients ranged from 9 months to 80 years. Cell doses were protocol specific and ranged from 104/kg up to 3 ×108/m2. Patients were premedicated with diphenhydramine (0.5-1mg/kg) and acetaminophen (10mg/kg up to a maximum of 625mg) prior to infusion. All cellular products were cryopreserved and administered intravenously over 1-15 minutes immediately after thawing. There were no Grade 3-4 infusion reactions during initial monitoring or 24 hour follow-up. Twenty four grade 1-2, non-severe adverse events (AEs) occurred in 21 infusions either during or immediately following infusion (up to 6 hours). The most common AEs were nausea and vomiting (10/24; 41.6%), most likely due to DMSO used in cryopreservation of T cell products, and hypotension (20.8%), attributable to diphenhydramine pre-medication. An additional 22 non-severe events within 24 hours of infusion were reported, the most common of which were fever (with negative blood cultures)/chills/constitutional symptoms (6/22; 27.3%) and nausea/vomiting (4/22; 18.2%) Overall, a total of 46 non-severe adverse events were noted within 24 hours of T cell product infusion (12.56%). A Fisher's exact analysis of all T cell product infusions grouped by patient age, patient ethnicity, or cell source revealed no association with increased risk. T cells from both allogeneic and autologous sources produced similar adverse events in terms of type, frequency, and severity, and allogeneic cells that were mismatched at > 2 HLA antigens had the same AEs as donor T cells matched at 5/6 or 6/6 HLA loci. We further analyzed the data using Poisson regression and the general estimating equation (GEE) model for correlated counts, to seek associations that may have been missed because AEs within a subject may not be statistically independent. By this analysis, we found decreased risks of adverse events in older patients (IRR 0.98; 95% CI 0.96-1.00; p=0.05), and increased risks of immediate (defined as occurring during the monitoring period) infusion-related events in patients reporting allergies (IRR 2.72; 95% CI 1.00-7.40; p=0.05). We thus conclude that infusion of the ex-vivo expanded T cell products used in these studies is a safe procedure associated with no severe reactions, that it is safe in the outpatient setting and that monitoring can be limited to an hour after infusion. As many of the AEs observed were due to diphenhydramine premedication, a lower dose (0.25mg/kg) of this agent may be preferred. Disclosures No relevant conflicts of interest to declare.

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The Oncogenic Fusionprotein NPM-ALK Cooperates with Bcl2 To Induce T-Cell Lymphomas in Mice.

Blood ◽

10.1182/blood.v108.11.2058.2058 ◽

2006 ◽

Vol 108 (11) ◽

pp. 2058-2058

Author(s):

Cornelius Miething ◽

Rebekka Grundler ◽

Claudia Mugler ◽

Anette Bauer ◽

Georg Häcker ◽

...

Keyword(s):

T Cells ◽

Cell Death ◽

T Cell ◽

Normal Growth ◽

Lymphoid Cells ◽

Retroviral Infection ◽

T Cell Lymphomas ◽

Human T Cell ◽

Bcl2 Expression

Abstract The NPM-ALK fusion oncogene arising from the t(2;5) translocation has been shown to transform lymphoid cells in culture and induce tumors in mice. In a previous report, we have demonstrated that expression of NPM-ALK in a murine retroviral infection/transplantation model leads to histiocytic and plasmacytoid tumors in mice. In the earlier model, we did not find any signs of a T-cell malignancy in the transplanted animals, although control animals transplanted with an empty vector expressing EGFP demonstrated successful targeting of the T-cell compartment. To further delineate the effects of NPM-ALK expression in T-cells in cell culture, we infected a human T-cell line (Jurkat) with NPM-ALK. Interestingly, NPM-ALK expressing cells demonstrated an increased rate of apoptosis, whereas control infected cells showed normal growth without significant cell death. Bcl2 levels were reduced in the NPM-ALK expressing cells and exogenous Bcl2 expression could partially rescue NPM-ALK induced cell death. We therefore investigated the effect of increased Bcl2 expression in vivo by infection of either C57B6 wild type or vav-Bcl2 transgenic mice derived BM cells with NPM-ALK and subsequent transplantation into lethally irradiated recipient mice. Whereas the control mice mostly developed the previously described histiocytic malignancy without significant T-cell involvement, all mice receiving NPM-ALK and Bcl2 coexpressing cells displayed a thymus derived T-cell lymphoma with infiltration of the thymus, lymphnodes, spleen and to a lesser extent also the bone marrow, where the histiocytic phenoype predominated. The malignant T-cells expressed Thy1.2, CD4 and NPM-ALK, but were mostly TdT negative. Our results implicate that Bcl2 cooperates with NPM-ALK in the induction of T-cell lymphomas, suggesting that NPM-ALK may require additional hits to suppress apoptosis and induce full transformation in T-cells.

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Low-Dose Alemtuzumab Is Uniquely Effective in Refractory Leukemic Cutaneous T Cell Lymphoma (L-CTCL).

Blood ◽

10.1182/blood.v114.22.3748.3748 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3748-3748 ◽

Cited By ~ 5

Author(s):

David C. Fisher ◽

Marianne Tawa ◽

Michele Walsh ◽

Rachael A Clark ◽

Thomas S. Kupper

Keyword(s):

T Cells ◽

T Cell ◽

Peripheral Blood ◽

Low Dose ◽

Conflicts Of Interest ◽

Clinical Signs ◽

Hematologic Malignancies ◽

Infectious Complications ◽

Conventional Dose ◽

Increased Risk

Abstract Abstract 3748 Poster Board III-684 Sezary Syndrome and other Cutaneous T Cell Lymphomas with peripheral blood involvement (collectively termed leukemic CTCL, or L-CTCL) are often refractory to multiple therapies. Alemtuzumab, an antibody directed against the pan-lymphocyte antigen CD52, has been used to treat multiple hematologic malignancies, including L-CTCL. However, conventional treatment regimens are associated with an increased risk of infections, and this is of particular concern in CTCL patients with compromised skin integrity. We have treated six L-CTCL patients with a modified regimen of alemtuzumab: 10mg/kg, subcutaneously, three times weekly for six weeks (1/3 of the conventional dose). All patients had had disease for >3 years duration, skin biopsies consistent with CTCL, elevated absolute CD4 counts, CD4/CD8 ratios of >10 and were refractory to at least two prior therapies, including extracorporeal photochemotherapy, interferon, and single and combination agent chemotherapy. In five of six patients, the malignant clone was identifiable using a Vb family specific monoclonal antibody; all cells of the malignant clonotype strongly expressed CD52. Within three weeks, all six patients achieved clearance of detectable T and B cells in peripheral blood, including loss of the malignant clone. In parallel, all patients developed clearing of erythroderma, relief of pruritus, and by the end of the six week treatment period, all patients had complete to near complete resolution of all clinical signs of disease. Isolation of T cells from a skin biopsy of one patient in complete remission revealed that <6% of T cells resident in skin expressed the malignant Vb subunit. At this reduced dose, no infectious complications were encountered. We conclude from that low-dose Aletuzumab is a well tolerated, safe, and highly effective therapy in a carefully selected population of patients with refractory L-CTCL. Disclosures: No relevant conflicts of interest to declare.

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Homeostatic Regulation of Apoptosis Governs Thymus Regeneration

Blood ◽

10.1182/blood-2019-131513 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 587-587

Author(s):

Sinéad Kinsella ◽

Kirsten Cooper ◽

Lorenzo Iovino ◽

Paul DeRoos ◽

Reema Jain ◽

...

Keyword(s):

T Cell ◽

Receptor Activation ◽

Acute Injury ◽

Rational Approach ◽

Post Transplant ◽

T Cell Reconstitution ◽

Tam Receptors ◽

Bmp4 Expression ◽

Thymocyte Apoptosis ◽

Thymic Regeneration

Although the thymus has a remarkable capacity for repair following acute injury, such as that caused by the conditioning required for successful hematopoietic cell transplant (HCT), the mechanisms underlying this endogenous regeneration remain poorly understood. Delayed T cell reconstitution occurs following thymus insult and can exceed more than a year post-transplant due to a delay in full recovery of thymic output, function and T cell repertoire. Therefore, strategies to enhance T cell reconstitution post-transplant represents a rational approach to significantly improve the overall outcome of allo-HCT. We propose that enhancing thymic function will boost T cell reconstitution and substantially increase immune responses following allo-HCT. Our recent studies have identified two critical pathways that govern thymic regeneration; centered on secretion of BMP4 by endothelial cells (ECs) and IL-22 by innate lymphoid cells (Dudakov 2012 Science 336:91; Dudakov 2017 Blood 130:933; Wertheimer 2018 Sci Immunol 3:19). However, the specific regulatory mechanisms that trigger these regeneration-associated factors (RAFs) after damage remain unclear. Given that our prior work revealed that the presence of DP thymocytes suppresses the production of RAFs like IL-23, a key downstream mediator of IL-22; and the high basal rate of thymocyte apoptosis, as apoptotic thymocytes form the bulk of developing T cells, we hypothesized that apoptotic DP thymocytes were mediating this suppression of RAFs under homeostatic conditions. Upon injury, loss of DP thymocytes leads to reduced apoptotic signaling and reduced suppression of RAFs, triggering thymic recovery (Fig 1A). Consistent with this hypothesis, our preliminary data shows a significantly reduced number of apoptotic thymocytes after total body irradiation (TBI, 550 cGy), as measured by cleaved caspase 3 levels (Fig 1B). Additionally, co-culture of apoptotic thymocytes results in reduced Bmp4 expression in ECs, which is rescued by inhibition of thymocyte apoptosis using the pan-caspase inhibitor zVAD-FMK (Fig 1C). One way in which apoptotic thymocytes could induce this suppression of RAFs is via TAM receptor activation, which is supported by our data demonstrating increased Bmp4 expression in ECs treated with a pan-TAM receptor antagonist and subsequently co-cultured with apoptotic thymocytes (Fig 1D). Interestingly, TAM receptors can activate Rac1, a Rho GTPases involved in actin cytoskeletal rearrangement; converging neatly on our previous data showing that inhibition of Rac1 with small molecule inhibitors led to robust induction of Bmp4 and Il23 expression. Therefore, we propose that in steady-state, apoptotic thymocytes activate TAM receptors on ECs and DCs and induce intracellular activation of Rac1, which ultimately suppresses the production of BMP4 and IL-23; but after damage, when the number of apoptotic thymocytes drops precipitously, this suppression is abrogated, allowing for thymic regeneration (Fig 1E). Importantly, we demonstrate here that this pathway can be therapeutically targeted, as inhibition of Rac1 in vivo with EHT1864 enhances thymus cellularity in models of acute injury (Fig. 1F), and age (Fig. 1G). As post-transplant T cell deficiency is associated with an increased risk of infections, relapse of malignancy, and the development of secondary malignancies, identifying molecular targets to enhance thymic recovery will aid in the development of therapeutics with imminent clinical need. These findings not only reveal a novel molecular mechanism governing tissue regeneration, but also offer a potentially superior therapeutic strategy for boosting thymic regeneration and T cell reconstitution after damage such as that caused by allo-HCT, infection or cytoreductive therapy. Disclosures No relevant conflicts of interest to declare.

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Immunogenomic Gene Signature of Cell-Death Associated Genes with Prognostic Implications in Lung Cancer

Cancers ◽

10.3390/cancers13010155 ◽

2021 ◽

Vol 13 (1) ◽

pp. 155

Author(s):

Pankaj Ahluwalia ◽

Meenakshi Ahluwalia ◽

Ashis K. Mondal ◽

Nikhil Sahajpal ◽

Vamsi Kota ◽

...

Keyword(s):

Lung Cancer ◽

T Cells ◽

Cell Death ◽

T Cell ◽

High Risk ◽

Lung Adenocarcinoma ◽

Risk Group ◽

High Risk Group ◽

Free Survival ◽

Cell Death Pathways

Lung cancer is one of the leading causes of death worldwide. Cell death pathways such as autophagy, apoptosis, and necrosis can provide useful clinical and immunological insights that can assist in the design of personalized therapeutics. In this study, variations in the expression of genes involved in cell death pathways and resulting infiltration of immune cells were explored in lung adenocarcinoma (The Cancer Genome Atlas: TCGA, lung adenocarcinoma (LUAD), 510 patients). Firstly, genes involved in autophagy (n = 34 genes), apoptosis (n = 66 genes), and necrosis (n = 32 genes) were analyzed to assess the prognostic significance in lung cancer. The significant genes were used to develop the cell death index (CDI) of 21 genes which clustered patients based on high risk (high CDI) and low risk (low CDI). The survival analysis using the Kaplan–Meier curve differentiated patients based on overall survival (40.4 months vs. 76.2 months), progression-free survival (26.2 months vs. 48.6 months), and disease-free survival (62.2 months vs. 158.2 months) (Log-rank test, p < 0.01). Cox proportional hazard model significantly associated patients in high CDI group with a higher risk of mortality (Hazard Ratio: H.R 1.75, 95% CI: 1.28–2.45, p < 0.001). Differential gene expression analysis using principal component analysis (PCA) identified genes with the highest fold change forming distinct clusters. To analyze the immune parameters in two risk groups, cytokines expression (n = 265 genes) analysis revealed the highest association of IL-15RA and IL 15 (> 1.5-fold, p < 0.01) with the high-risk group. The microenvironment cell-population (MCP)-counter algorithm identified the higher infiltration of CD8+ T cells, macrophages, and lower infiltration of neutrophils with the high-risk group. Interestingly, this group also showed a higher expression of immune checkpoint molecules CD-274 (PD-L1), CTLA-4, and T cell exhaustion genes (HAVCR2, TIGIT, LAG3, PDCD1, CXCL13, and LYN) (p < 0.01). Furthermore, functional enrichment analysis identified significant perturbations in immune pathways in the higher risk group. This study highlights the presence of an immunocompromised microenvironment indicated by the higher infiltration of cytotoxic T cells along with the presence of checkpoint molecules and T cell exhaustion genes. These patients at higher risk might be more suitable to benefit from PD-L1 blockade or other checkpoint blockade immunotherapies.

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Type I interferons affect the metabolic fitness of CD8+ T cells from patients with systemic lupus erythematosus

Nature Communications ◽

10.1038/s41467-021-22312-y ◽

2021 ◽

Vol 12 (1) ◽

Cited By ~ 1

Author(s):

Norzawani Buang ◽

Lunnathaya Tapeng ◽

Victor Gray ◽

Alessandro Sardini ◽

Chad Whilding ◽

...

Keyword(s):

Systemic Lupus Erythematosus ◽

T Cells ◽

Cell Death ◽

T Cell ◽

Lupus Erythematosus ◽

Type I Interferons ◽

Type I ◽

Type I Ifn ◽

Systemic Lupus ◽

Mitochondrial Abnormalities

AbstractThe majority of patients with systemic lupus erythematosus (SLE) have high expression of type I IFN-stimulated genes. Mitochondrial abnormalities have also been reported, but the contribution of type I IFN exposure to these changes is unknown. Here, we show downregulation of mitochondria-derived genes and mitochondria-associated metabolic pathways in IFN-High patients from transcriptomic analysis of CD4+ and CD8+ T cells. CD8+ T cells from these patients have enlarged mitochondria and lower spare respiratory capacity associated with increased cell death upon rechallenge with TCR stimulation. These mitochondrial abnormalities can be phenocopied by exposing CD8+ T cells from healthy volunteers to type I IFN and TCR stimulation. Mechanistically these ‘SLE-like’ conditions increase CD8+ T cell NAD+ consumption resulting in impaired mitochondrial respiration and reduced cell viability, both of which can be rectified by NAD+ supplementation. Our data suggest that type I IFN exposure contributes to SLE pathogenesis by promoting CD8+ T cell death via metabolic rewiring.

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Keratinocyte growth factor enhances DNA plasmid tumor vaccine responses after murine allogeneic bone marrow transplantation

Blood ◽

10.1182/blood-2008-05-155697 ◽

2009 ◽

Vol 113 (7) ◽

pp. 1574-1580 ◽

Cited By ~ 20

Author(s):

Robert R. Jenq ◽

Christopher G. King ◽

Christine Volk ◽

David Suh ◽

Odette M. Smith ◽

...

Keyword(s):

Bone Marrow ◽

T Cells ◽

T Cell ◽

Keratinocyte Growth Factor ◽

Allogeneic Bone Marrow Transplantation ◽

Allogeneic Bone ◽

Effector Cells ◽

Cd8 Cells ◽

T Cell Reconstitution ◽

Dna Plasmid

Abstract Keratinocyte growth factor (KGF), which is given exogenously to allogeneic bone marrow transplantation (allo-BMT) recipients, supports thymic epithelial cells and increases thymic output of naive T cells. Here, we demonstrate that this improved T-cell reconstitution leads to enhanced responses to DNA plasmid tumor vaccination. Tumor-bearing mice treated with KGF and DNA vaccination have improved long-term survival and decreased tumor burden after allo-BMT. When assayed before vaccination, KGF-treated allo-BMT recipients have increased numbers of peripheral T cells, including CD8+ T cells with vaccine-recognition potential. In response to vaccination, KGF-treated allo-BMT recipients, compared with control subjects, generate increased numbers of tumor-specific CD8+ cells, as well as increased numbers of CD8+ cells producing interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α). We also found unanticipated benefits to antitumor immunity with the administration of KGF. KGF-treated allo-BMT recipients have an improved ratio of T effector cells to regulatory T cells, a larger fraction of effector cells that display a central memory phenotype, and effector cells that are derived from a broader T-cell–receptor repertoire. In conclusion, our data suggest that KGF can function as a potent vaccine adjuvant after allo-BMT through its effects on posttransplantation T-cell reconstitution.

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Susceptibility to cell death is a dominant phenotype: triggering of activation-driven T-cell death independent of the T-cell antigen receptor complex

Molecular and Cellular Biology ◽

10.1128/mcb.12.1.379-385.1992 ◽

1992 ◽

Vol 12 (1) ◽

pp. 379-385

Author(s):

G Nickas ◽

J Meyers ◽

L D Hebshi ◽

J D Ashwell ◽

D P Gold ◽

...

Keyword(s):

T Cells ◽

Cell Death ◽

T Cell ◽

Interleukin 2 ◽

Antigen Receptor ◽

Alternative Activation ◽

Receptor Complex ◽

T Cell Antigen Receptor ◽

Cell Antigen Receptor ◽

Cell Antigen

The failure of Thy-1 and Ly-6 to trigger interleukin-2 production in the absence of surface T-cell antigen receptor complex (TCR) expression has been interpreted to suggest that functional signalling via these phosphatidylinositol-linked alternative activation molecules is dependent on the TCR. We find, in contrast, that stimulation of T cells via Thy-1 or Ly-6 in the absence of TCR expression does trigger a biological response, the cell suicide process of activation-driven cell death. Activation-driven cell death is a process of physiological cell death that likely represents the mechanism of negative selection of T cells. The absence of the TCR further reveals that signalling leading to activation-driven cell death and to lymphokine production are distinct and dissociable. In turn, the ability of alternative activation molecules to function in the absence of the TCR raises another issue: why immature T cells, thymomas, and hybrids fail to undergo activation-driven cell death in response to stimulation via Thy-1 and Ly-6. One possibility is that these activation molecules on immature T cells are defective. Alternatively, susceptibility to activation-driven cell death may be developmentally regulated by TCR-independent factors. We have explored these possibilities with somatic cell hybrids between mature and immature T cells, in which Thy-1 and Ly-6 are contributed exclusively by the immature partner. The hybrid cells exhibit sensitivity to activation-driven cell death triggered via Thy-1 and Ly-6. Thus, the Thy-1 and Ly-6 molecules of the immature T cells can function in a permissive environment. Moreover, with regard to susceptibility to Thy-1 and Ly-6 molecules of the immature T cells can function in a permissive environment. Moreover, with regard to susceptibility to Thy-1 and Ly-6 triggering, the mature phenotype of sensitivity to cell death is genetically dominant.

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Combination cancer immunotherapy targeting PD-1 and GITR can rescue CD8+T cell dysfunction and maintain memory phenotype

Science Immunology ◽

10.1126/sciimmunol.aat7061 ◽

2018 ◽

Vol 3 (29) ◽

pp. eaat7061 ◽

Cited By ~ 44

Author(s):

Bei Wang ◽

Wen Zhang ◽

Vladimir Jankovic ◽

Jacquelynn Golubov ◽

Patrick Poon ◽

...

Keyword(s):

T Cells ◽

Cell Death ◽

T Cell ◽

Programmed Cell Death ◽

Cancer Immunotherapy ◽

Effector Memory ◽

Cell Phenotype ◽

Checkpoint Inhibition ◽

Cell Dysfunction ◽

T Cell Dysfunction

Most patients with cancer do not develop durable antitumor responses after programmed cell death protein 1 (PD-1) or programmed cell death ligand 1(PD-L1) checkpoint inhibition monotherapy because of an ephemeral reversal of T cell dysfunction and failure to promote long-lasting immunological T cell memory. Activating costimulatory pathways to induce stronger T cell activation may improve the efficacy of checkpoint inhibition and lead to durable antitumor responses. We performed single-cell RNA sequencing of more than 2000 tumor-infiltrating CD8+T cells in mice receiving both PD-1 and GITR (glucocorticoid-induced tumor necrosis factor receptor–related protein) antibodies and found that this combination synergistically enhanced the effector function of expanded CD8+T cells by restoring the balance of key homeostatic regulators CD226 and T cell immunoreceptor with Ig and ITIM domains (TIGIT), leading to a robust survival benefit. Combination therapy decreased CD8+T cell dysfunction and induced a highly proliferative precursor effector memory T cell phenotype in a CD226-dependent manner. PD-1 inhibition rescued CD226 activity by preventing PD-1–Src homology region 2 (SHP2) dephosphophorylation of the CD226 intracellular domain, whereas GITR agonism decreased TIGIT expression. Unmasking the molecular pathways driving durable antitumor responses will be essential to the development of rational approaches to optimizing cancer immunotherapy.

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