scholarly journals Stat3 Regulates Alloreactive T Cell Susceptibility Towards PD-L1-Mediated Tolerance Signaling, Gvhd and GVL Activity

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3323-3323
Author(s):  
Shijie Yang ◽  
Xiaoqi Wang ◽  
Yuankun Zhang ◽  
Deye Zeng ◽  
Qingxiao Song ◽  
...  
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Acute Gvhd ◽  
Chronic Gvhd ◽  
B Cell Lymphoma ◽  
Tissue Expression ◽  
Lymphoid Tissues ◽  
Target Tissue ◽  
Donor T Cells

Abstract Prevention of graft versus host disease (GVHD) while preserving graft-versus-leukemia/lymphoma (GVL) activity of alloreactive donor T cells remains an elusive and long-sought goal. We and others reported that Stat3 deficiency in donor T cells results in expansion of Foxp3+ Treg cells and reduction of pathogenic Th17 cells, leading to prevention of chronic GVHD. We have now tested whether Stat3 deficiency in donor T cells can prevent acute GVHD while preserving GVL activity. We transplanted wild-type (WT) or Stat3-/- T cells from C57BL/6 (H-2b) donors into irradiated WT BALB/c recipients bearing B cell lymphoma line BCL1 or aggressive acute lymphocytic leukemia (ALL) cells. WT donor T cells caused acute GVHD, as expected. Stat3-/- donor T cells did not cause acute GVHD but still had strong GVL activity. This separation of GVL activity from GVHD was associated with augmented expansion and impaired tolerance by Stat3-/- T cells in lymphoid tissues such as the spleen. In contrast, tolerance by Stat3-/- T cells was enhanced in GVHD target tissues by different mechanisms. The yield of Stat3-/- T cells in gut tissues was lower than the yield of WT T cells due to the markedly higher apoptosis of Stat3-/- T cells compared to WT T cells. The yield of Stat3-/- T cells in the lung and liver was not lower than the yield of WT T cells, but expression of anergy/exhaustion markers such as PD-1 and KLRG1 was markedly higher in Stat3-/- T cells than in WT T cells. We recently reported that GVHD tissue expression of PD-L1 can tolerize donor CD8+ T cells in the absence of donor CD4+ T cells, but not when CD4+ and CD8+ T cells were given together. In contrast, PD-L1 expression in recipient GVHD target tissues tolerized Stat3-/- donor T cells when both CD4+ T cells and CD8+ T cells were given together. The induction of tolerance in Stat3-/- T cells by GVHD target tissue expression of PD-L1 depended on PD-L1/PD-1 interaction, which led to marked reduction of glycolysis in Stat3-/- T cells but not in WT T cells. These observations fit with previous findings that enhanced glycolysis was associated with enhanced GVHD activity of alloreactive T cells, as reported by Xue-zhong Yu's group. Our results indicate that Stat3 deficiency in donor T cells can augment their susceptibility to tissue PD-L1-mediated tolerance mechanisms such as down-regulation of glycolysis. Current experiments are testing whether Stat3 knockdown in mature T cells in the graft can prevent GVHD while preserving GVL activity. (Grant support: R01AI066008 to Zeng) Disclosures No relevant conflicts of interest to declare.

scholarly journals Host Tissue PD-L1 Separates GVL Effect from Gvhd after Temporary Depletion of Donor CD4+ T Cells Early after HCT

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1882-1882
Author(s):  
Xiong Ni ◽  
Qingxiao Song ◽  
Ruishu Deng ◽  
Hua Jin ◽  
Kaniel M. Cassady ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Research Funding ◽  
Chronic Gvhd ◽  
Cd8 T Cell ◽  
Tissue Expression ◽  
Lymphoid Tissues ◽  
Recipient Tissue

Abstract Recipient tissue expression of programmed death-ligand 1 (PD-L1, B7H1) down-regulates graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation (HCT), but this information has not been translated clinically. Here we demonstrate a critical role for recipient PD-L1 expression in preventing both acute and chronic GVHD while preserving graft-versus-leukemia (GVL) effects when donor CD4+ T cells are temporarily depleted in vivo early after HCT. Depletion of donor CD4+ T cells increases serum IFN-γ concentrations and enhances recipient tissue expression of PD-L1 and donor CD8+ T cell expression of the PD-L1 receptors CD80 and PD-1. In GVHD target tissues, depletion of CD4+ T cells increases anergy and apoptosis of infiltrating CD8+ T cells in a manner that depends on recipient PD-L1 expression, thereby preventing damage to intestinal Paneth cells and stem cells, hepatocytes, and thymic medullary epithelial cells, and preventing both acute and chronic GVHD. In lymphoid tissues, depletion of CD4+ T cells augments CD8+ T cell proliferation without increasing CD8+ T cell anergy or apoptosis, resulting in expansion of donor CD8+ T cells and strong GVL effects. Therefore, temporary depletion of donor CD4+ T cells early after HCT represents a novel approach for preventing GVHD while preserving GVL effects. This work was supported by NIH R01 AI066008 and Nesvig Lymphoma Fundation (to D.Z.) and by NSFC 81090413, 81270638 (to J.W.). Disclosures Forman: Amgen: Consultancy; Mustang: Research Funding. Martin:Neovii: Research Funding; RegImmune: Research Funding; Enlivex: Consultancy; Janssen: Consultancy; Pfizer: Consultancy; Pharmacyclics: Consultancy.

Recovery of Functional EBV Specific T Cells Is Not Impaired In Patients with Chronic Gvhd.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1286-1286
Author(s):  
Mette Hoegh-Petersen ◽  
Yiping Liu ◽  
Stephanie Liu ◽  
Alejandra Ugarte-Torres ◽  
Kevin Fonseca ◽  
...  
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Epstein Barr Virus ◽  
Acute Gvhd ◽  
De Novo ◽  
Chronic Gvhd ◽  
Cd8 Cells ◽  
Barr Virus ◽  
Epstein Barr

Abstract Abstract 1286 Introduction: T cell expression of PD-1, a marker of functional exhaustion manifested by inability to produce cytokines upon stimulation, is upregulated in patients with acute GHVD. This is thought to explain at least in part why patients with acute GVHD have frequent infections (Gallez-Hawkins et al, BBMT15:872, 2009). Here we wished to evaluate whether this is true also for chronic GVHD. Patients and Methods: We studied 17 allogeneic HCT recipients for AML who have not developed acute or chronic GVHD by day 84. Their blood was drawn on day 84, 180 and 365. Between day 84 and 365, 7 patients did and 10 patients did not develop chronic GVHD needing systemic immunosuppressive therapy (de novo, ie, without preceding acute GVHD). Onset of the chronic GVHD was on median day 103 (range, 90–147). We studied total CD4 and CD8 T cells as well as Epstein-Barr virus (EBV)-specific CD4 and CD8 T cells, as patients with chronic GVHD are at risk of EBV disease (Landgren et al, Blood,14:4992, 2009). Blood mononuclear cells were stimulated with Epstein-Barr virus (EBV) lysate, EBNA3A+B+C overlapping peptides, no or irrelevant stimulus as negative control, or Staphylococcal enterotoxin B as positive control. After overnight incubation, expression of IFNγ, TNFα, IL2 and PD-1 on CD3+CD4+CD8- or CD3+CD4-CD8+ cells was determined by flow cytometry. Cells expressing IFNγ, TNFα, IL2 or their combinations were enumerated. PD-1 expression was quantified using beads coated with anti-mouse antibody (Quantum Simply Cellular, Bangs Laboratories) and expressed as antibody binding capacity units (ABC) (dynamic range, approximately 300 to 500,000 ABC units per cell). Results: PD-1 expression on total, EBV lysate-specific or EBNA3-specific CD4 or CD8 T cells was not significantly higher among patients who did vs did not develop chronic GVHD. On the contrary, there was a trend toward lower PD-1 expression on EBV lysate-specific CD4 and CD8 T cells and EBNA3-specific CD4 T cells in patients who developed chronic GVHD. This was significant (p<.05, Mann-Whitney test) for EBV lysate-specific CD4 T cells on day 84, EBV lysate-specific CD8 T cells on day 180, EBV lysate-specific CD4 and CD8 T cells on day 365, EBNA3-specific CD4 T cells on day 84 and EBNA3-specific CD4 T cells on day 365. Consistent with that, absolute counts of total, EBV lysate-specific or EBNA3-specific T cells were not significantly lower in patients who did vs did not develop chronic GVHD. On the contrary, there was a trend toward higher EBV lysate-specific and EBNA3-specific CD4 or CD8 T cell counts in patients who developed chronic GVHD. This was significant on day 84 for total EBV lysate-specific CD4 and CD8 cells, EBV lysate-specific CD4+IFNγ+ cells and CD8+IFNγ+ cells, and total EBNA3-specific CD4 cells, EBNA3-specific CD4+IFNγ+ cells, CD4+IL2+ cells, CD4+IFNγ+TNFα+IL2+ cells and CD8+IFNγ+ cells. Conclusion: De novo chronic GvHD and its treatment do not adversely affect the counts of functional EBV specific T cells. Disclosures: No relevant conflicts of interest to declare.

Bone Marrow Derived, De Novo Generated CD4+ T Cells Are Previously Unsuspected Participants in CD8+ T Cell-Mediated Graft-Versus-Host Disease.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 581-581
Author(s):  
Yi Zhang ◽  
Elizabeth Hexner ◽  
Dale Frank ◽  
Joe Gerard ◽  
Frank Kung ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Acute Gvhd ◽  
De Novo ◽  
Memory T Cells ◽  
Tissue Injury ◽  
Chronic Gvhd ◽  
Host Tissue

Abstract Although mature CD8+ T cells are known to be major effectors of acute GVHD, patients receiving T cell-depleted allografts remain at high risk for chronic GVHD. To what extent CD8+, CD4+ or both T cell subsets contribute to this chronic immunopathology is not known. We have recently demonstrated that alloreactive memory T cells develop in mice with acute GVHD and account for the persistence of host tissue injury (Journal of Immunology, 2005;174:3051). Based on these findings, we now ask whether de novo generated donor T cells from engrafted T-BM themselves contribute to persistent host tissue injury in GVHD. Confirming previous observations, we found that transplantation of lethally irradiated C57BL/6SJL (B6, CD45.1) mice with highly purified C3H.SW (CD45.2) CD4+ naïve T cells did not cause GVHD, but mice receiving highly purified CD8+ naïve T cells together with C3H.SW T-BM, suffered severe acute GVHD. Surprisingly, in these mice receiving only CD8+ T cells, a substantial number of donor CD4+ T cells as well as CD8+ T cells were detected in GVHD target tissues, indicating that these infiltrating CD4+ T cells had arisen de novo from the transplanted T-BM. Donor CD4+ T cells recovered from GVHD mice expressed surface markers of activated effector/effector memory T cells, including CD25, CD69, CXCR3, and CD44hiCD62Llo. In response to host DCs, purified GVHD CD4+ T cells proliferated and expanded 4-5X more, and produced 10X higher levels of IFN-γ than did CD4+ T cells derived from B6 mice receiving C3H.SW T-BM alone. Furthermore, adoptive transfer of these in vivo generated GVHD CD4+ T cells, without CD8+ T cells, into secondary irradiated B6 recipients induced clinical GVHD characterized by delayed onset, weight loss, diarrhea, and lymphopenia, but without cutaneous inflammation. Histologic examination demonstrated chronic inflammation in the liver and intestinal tract, including epithelial apoptosis. Thymic pathology was dramatic in secondary B6 recipients of GVHD CD4+ T cells, including thymic atrophy, loss of thymic cortex, and infiltration of large amount of tingible macrophages. Taken together, these results demonstrate that donor bone marrow derived, de novo generated CD4+ T cells also contribute to GVHD together with transferred mature CD8+ T cells. Moreover, they suggest that these CD4+ T cells, in concert with alloreactive memory CD8+ T cells that develop during the evolution of GVHD, cause the persistence of acute GVHD and its subsequent progression into chronic GVHD. Thus, donor BM-derived, de novo generated CD4+ T cells are the “Hidden Dragon” of CD8+ T cell-mediated GVHD. Understanding how these CD4+ T cells are generated and regulated will prove to be critical to the prevention and treatment of both acute and chronic GVHD.

scholarly journals Stat3-/- Alloreactive Donor T Cells Reduce FAO but Increase Leakage of ROS in Response to PD-1 Signaling Triggered By Host-Tissue PD-L1, Leading to Prevention of Gvhd While Preserving GVL Effect

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 198-198
Author(s):  
Xiaoqi Wang ◽  
Shijie Yang ◽  
Yating Wang ◽  
Xiwei Wu ◽  
Martha Salas ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Conflicts Of Interest ◽  
Chronic Gvhd ◽  
Host Tissue ◽  
Acid Oxidation ◽  
Lymphoid Tissues ◽  
Alloreactive T Cells ◽  
Donor T Cells

The GVHD pathogenicity of alloreactive T cells is associated with enhanced glycolysis or enhanced fatty acid oxidation (FAO). PD-1 signaling in T cells inhibits glycolysis but augments FAO. Host tissue PD-L1 interaction with PD-1 on activated alloreactive T cells is not able to effectively prevent acute GVHD mediated by donor CD4+ and CD8+ T cells together, although it can reduce the severity of the disease. Using a murine HCT model of C57BL/6 donor to BALB/c recipient, we show that although WT T cells (CD4+ and CD8+ T cells together) induced lethal GVHD at 1-5 x106/mouse, the same dose of Stat3-/- donor T cells induced little signs of acute or chronic GVHD because of induction of T cell anergy, exhaustion and apoptosis, but with retention of a strong GVL effect. This induction of tolerance depends on donor T cell PD-1 interaction with host-tissue PD-L1, because Stat3-/- T cells induce severe lethal GVHD in the PD-L1-/- recipients and in WT recipients treated with blocking anti-PD-1 mAb. The tolerance of Stat3-/- donor T cells induced by PD-1 signaling is associated with lower FAO and mitochondria membrane potential (MMP) but higher ROS leakage, with little difference in glycolysis, as compared to non-tolerant WT T cells. In the absence of PD-1 signaling, Stat3-/- T cells manifest markedly enhanced glycolysis and loss of tolerance. These results indicate that activated donor T cell PD-1 interaction with host-tissue PD-L1 reduces glycolysis and reduces their GVHD capacity. In addition, absence of mitochondrial pStat3 in Stat3-/- donor T cells leads to reduced FAO and MMP but increased ROS leakage, resulting in effective anergy, exhaustion, and apoptosis of tissue infiltrating donor T cells and prevention of GVHD. At the same time, the reduced expression of PD-L1 in recipient lymphoid tissues allows donor T cell expansion and strong GVL activity. Our studies have revealed novel roles of mitochondria pStat3 in regulating PD-1 signaling, T cell metabolism and tolerance. (Grant support: R01AI066008 to Zeng) . Disclosures No relevant conflicts of interest to declare.

Chemokine-mediated tissue recruitment of CXCR3+ CD4+ T cells plays a major role in the pathogenesis of chronic GVHD

Blood ◽  
2012 ◽  
Vol 120 (20) ◽  
pp. 4246-4255 ◽  
Author(s):  
Joanne E. Croudace ◽  
Charlotte F. Inman ◽  
Ben. E. Abbotts ◽  
Sandeep Nagra ◽  
Jane Nunnick ◽  
...  
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Acute Gvhd ◽  
Chronic Gvhd ◽  
Central Feature ◽  
Serum Concentrations ◽  
Cd4 Cells ◽  
Hemopoietic Cells ◽  
Immune Mediated

Abstract Chemokines regulate the migration of hemopoietic cells and play an important role in the pathogenesis of many immune-mediated diseases. Intradermal recruitment of CD8+ T cells by CXCL10 is a central feature of the pathogenesis of cutaneous acute GVHD (aGVHD), but very little is known about the pathogenesis of chronic GVHD (cGVHD). Serum concentrations of the 3 CXCR3-binding chemokines, CXCL9, CXCL10, and CXCL11, were found to be markedly increased in patients with active cGVHD of the skin (n = 8). An 80% decrease in CD4+ cells expressing CXCR3 was seen in the blood of these patients (n = 5), whereas CD4+ cells were increased in tissue biopsies and were clustered around the central arterioles of the dermis. The well-documented increase in expression of CXCL10 in aGVHD therefore diversifies in cGVHD to include additional members of the CXCR3-binding family and leads to preferential recruitment of CD4+ T cells. These observations reveal a central role for chemokine-mediated recruitment of CXCR3+ T cells in cGVHD.

scholarly journals Functional analysis of clinical response to low-dose IL-2 in patients with refractory chronic graft-versus-host disease

2019 ◽  
Vol 3 (7) ◽  
pp. 984-994 ◽  
Author(s):  
Jennifer S. Whangbo ◽  
Haesook T. Kim ◽  
Sarah Nikiforow ◽  
John Koreth ◽  
Ana C. Alho ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Graft Versus Host Disease ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Low Dose ◽  
B Cell Lymphoma ◽  
Host Disease ◽  
Graft Versus Host ◽  
Response Groups

Abstract Patients with chronic graft-versus-host disease (cGVHD) have a paucity of regulatory CD4 T cells (CD4Tregs) that mediate peripheral tolerance. In clinical trials, daily low-dose interleukin-2 (IL-2) has been administered safely for prolonged periods in patients with steroid-refractory cGVHD. Peripheral CD4Tregs expand dramatically in all patients during IL-2 therapy but clinical improvement was observed in ∼50% of patients. Here, we examined the impact of low-dose IL-2 therapy on functional T-cell markers and the T-cell repertoire within CD4Tregs, conventional CD4 T cells (CD4Tcons), and CD8+ T cells. IL-2 had profound effects on CD4Tregs homeostasis in both response groups including selective expansion of the naive subset, improved thymic output, and increased expression of Ki67, FOXP3, and B-cell lymphoma 2 within CD4Tregs. Similar changes were not seen in CD4Tcons or CD8 T cells. Functionally, low-dose IL-2 enhanced, in vitro, CD4Treg-suppressive activity in both response groups, and all patient CD4Tcons were similarly suppressed by healthy donor CD4Tregs. High-throughput sequencing of the T-cell receptor β (TCRβ) locus demonstrated that low-dose IL-2 therapy increased TCR repertoire diversity and decreased evenness within CD4Tregs without affecting CD4Tcons or CD8 T cells. Using clone-tracking analysis, we observed rapid turnover of highly prevalent clones in CD4Tregs as well as the conversion of CD4Tcons to CD4Tregs. After 12 weeks of daily IL-2, clinical responders had a greater influx of novel clones within the CD4Treg compartment compared with nonresponders. Further studies to define the function and specificity of these novel CD4Treg clones may help establish the mechanisms whereby low-dose IL-2 therapy promotes immune tolerance.

Prophylactic Amotosalen-Treated Donor T-Cells Prevent Late CMV Infection in Allogeneic Bone Marrow Transplantation.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3024-3024
Author(s):  
Mohammad S. Hossain ◽  
John D. Robak ◽  
Edmund K. Waller
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Viral Infection ◽  
Cd8 T Cells ◽  
Immune Reconstitution ◽  
Chronic Gvhd ◽  
Mcmv Infection ◽  
Tnf Α ◽  
Donor T Cells ◽  
Ifn Γ

Abstract A major problem in allogeneic BMT is post transplant immunodeficiency leading to opportunistic infection and relapse. Previously we showed that amotosalen-treated allogeneic donor T cells given at the time of BMT and experimental murine cytomegalovirus (MCMV) infection could prevent lethal MCMV disease without producing GvHD. In this study we have focused on a more clinically applicable model where prophylactic amotosalen-treated allogeneic donor splenocytes are given at the time of BMT, followed by MCMV infection 100 days later. We observed that amotosalen-treated donor T-cells significantly expanded and responded well in presence of viral infection without inducing any GvHD, protected recipients against viral disease, and were associated with significantly improved hematopoietic engraftment and immune reconstitution. Methods: Using a parent to F1 mouse BMT model, splenocytes (3x106 untreated or 10x106 amotosalen-treated) from MCMV immunized C57BL/6 donors were transplanted along with 5x106 T-cell depleted bone marrow (TCD BM) from naïve congeneic mice into lethally irradiated (11Gy) CB6F1 recipients (C57BL/6 x Balb/C). Recipient mice were infected i.p. with a sublethal dose (5x104 pfu per mouse) of MCMV 100 days or more after transplant. Clinical chronic GvHD was monitored by weight loss, hair loss, ruffled fur, diarrhea, and decreased activity. Flow cytometry was used to quantitate T cell chimerism (in recipient PBMC, spleen, liver and thymus) and MCMV-peptide specific CD8+ T-cells (tetramer+ and IFN-γ producing). Serum IFN-γ and TNF-α were determined by ELISA. Liver and spleen viral loads were determined by counting PFU in tissue homogenates plated onto 3T3 confluent monolayers. Results: Recipients of untreated control donor splenocytes suffered from chronic GvHD within 100 days of transplant, while those that received amotosalen-treated splenocytes experienced no GvHD. In response to MCMV infection at 100 days post transplant, residual amotosalen-treated donor T-cells rapidly expanded over 25-fold within 10 days, but did not cause lethality or detectable GvHD. Expanded amotosalen-treated T-cells showed activated anti-viral responses and developed a memory phenotype at late phases of viral infection. PBMC, spleen and liver showed elevated levels of MCMV specific tetramer+, IFN-γ+, and TNF-α+ CD8+ T-cells that were associated with accelerated viral clearance within day 3 after viral infection. While expansion and generation of amotosalen-treated donor T-cells mostly occurred in the liver, the generation of donor bone marrow-derived new T-cells occurred through both the thymus and the liver. In contrast, recipients of untreated donor splenocytes had reduced thymic function, resulting in severely impaired immune reconstitution and decreased anti-viral immunity. Conclusion: Prophylactically administered amotosalen-treated allogeneic donor T cells 1) were almost completely devoid of GvHD activity, 2) promoted hematopoietic engraftment and improved immune reconstitution, and 3) persisted long-term (&gt;100 days) and successfully protected recipients from sublethal MCMV infection. Thus, infusion of amotosalen-treated donor T-cells at the time of transplantation is a clinically-attractive approach to adoptive anti-viral immunotherapy without chronic GvHD following hematopoietic progenitor cell transplantation.

Anti-GvHD Effect of Antithymocyte Globulin Is Mediated by Antibodies Binding to T Cells and Regulatory NK Cells, and Less So or Not at All by Antibodies Binding to Other Mononuclear Cell Subsets

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2346-2346
Author(s):  
Mette Hoegh-Petersen ◽  
Minaa Amin ◽  
Yiping Liu ◽  
Alejandra Ugarte-Torres ◽  
Tyler S Williamson ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
B Cells ◽  
Nk Cells ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Antithymocyte Globulin ◽  
Chronic Gvhd ◽  
Wilcoxon Test ◽  
Effector Memory

Abstract Abstract 2346 Introduction: Polyclonal rabbit-anti-human T cell globulin may decrease the likelihood of graft-vs-host disease (GVHD) without increasing the likelihood of relapse. We have recently shown that high levels of antithymocyte globulin (ATG) capable of binding to total lymphocytes are associated with a low likelihood of acute GVHD grade 2–4 (aGVHD) as well as chronic GVHD needing systemic therapy (cGVHD) but not increased likelihood of relapse (Podgorny PJ et al, BBMT 16:915, 2010). ATG is polyclonal, composed of antibodies for antigens expressed on multiple cell subsets, including T cells, B cells, NK cells, monocytes and dendritic cells. These cell subsets may play a role in the pathogenesis of GVHD. The anti-GVHD effect of ATG may be mediated through killing/inhibition of one or several of these cell subsets (eg, T cells) or their subsets (eg, naïve T cells as based on mouse experiments naïve T cells are thought to play a major role in the pathogenesis of GVHD). To better understand the mechanism of action of ATG on GVHD, we set out to determine levels of which ATG fraction (capable of binding to which cell subset) are associated with subsequent development of GVHD. Patients and Methods: A total of 121 patients were studied, whose myeloablative conditioning included 4.5 mg/kg ATG (Thymoglobulin). Serum was collected on day 7. Using flow cytometry, levels of the following ATG fractions were determined: capable of binding to 1. naïve B cells, 2. memory B cells, 3. naïve CD4 T cells, 4. central memory (CM) CD4 T cells, 5. effector memory (EM) CD4 T cells, 6. naïve CD8 T cells, 7. CM CD8 T cells, 8. EM CD8 T cells not expressing CD45RA (EMRA-), 9. EM CD8 T cells expressing CD45RA (EMRA+), 10. cytolytic (CD16+CD56+) NK cells, 11. regulatory (CD16-CD56high) NK cells, 12. CD16+CD56− NK cells, 13. monocytes and 14. dendritic cells/dendritic cell precursors (DCs). For each ATG fraction, levels in patients with versus without aGVHD or cGVHD were compared using Mann-Whitney-Wilcoxon test. For each fraction for which the levels appeared to be significantly different (p<0.05), we determined whether patients with high fraction level had a significantly lower likelihood of aGVHD or cGVHD than patients with low fraction level (high/low cutoff level was determined from ROC curve, using the point with maximum sum of sensitivity and specificity). This was done using log-binomial regression models, ie, multivariate analysis adjusting for recipient age (continuous), stem cell source (marrow or cord blood versus blood stem cells), donor type (HLA-matched sibling versus other), donor/recipient sex (M/M versus other) and days of follow up (continuous). Results: In univariate analyses, patients developing aGVHD had significantly lower levels of the following ATG fractions: binding to naïve CD4 T cells, EM CD4 T cells, naïve CD8 T cells and regulatory NK cells. Patients developing cGVHD had significantly lower levels of the following ATG fractions: capable of binding to naïve CD4 T cells, CM CD4 T cells, EM CD4 T cells, naïve CD8 T cells and regulatory NK cells. Patients who did vs did not develop relapse had similar levels of all ATG fractions. In multivariate analyses, high levels of the following ATG fractions were significantly associated with a low likelihood of aGVHD: capable of binding to naïve CD4 T cells (relative risk=.33, p=.001), EM CD4 T cells (RR=.30, p<.001), naïve CD8 T cells (RR=.33, p=.002) and regulatory NK cells (RR=.36, p=.001). High levels of the following ATG fractions were significantly associated with a low likelihood of cGVHD: capable of binding to naïve CD4 T cells (RR=.59, p=.028), CM CD4 T cells (RR=.49, p=.009), EM CD4 T cells (RR=.51, p=.006), naïve CD8 T cells (RR=.46, p=.005) and regulatory NK cells (RR=.55, p=.036). Conclusion: For both aGVHD and cGVHD, the anti-GVHD effect with relapse-neutral effect of ATG appears to be mediated by antibodies to antigens expressed on naïve T cells (both CD4 and CD8), EM CD4 T cells and regulatory NK cells, and to a lesser degree or not at all by antibodies binding to antigens expressed on B cells, cytolytic NK cells, monocytes or DCs. This is the first step towards identifying the antibody(ies) within ATG important for the anti-GVHD effect without impacting relapse. If such antibody(ies) is (are) found in the future, it should be explored whether such antibody(ies) alone or ATG enriched for such antibody(ies) could further decrease GVHD without impacting relapse. Disclosures: No relevant conflicts of interest to declare.

Upregulation of Immune Checkpoint Blockade Molecules Post Allogeneic Stem Cell Transplantation Is Necessary but Insufficient to Prevent GvHD

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1101-1101
Author(s):  
Mohammad Sohrab Hossain ◽  
Ghada M Kunter ◽  
Vicky Fayez Najjar ◽  
David L. Jaye ◽  
Edmund K. Waller
Keyword(s):  
T Cells ◽  
Transcription Factor ◽  
Stem Cell ◽  
T Cell ◽  
Cd8 T Cells ◽  
Acute Gvhd ◽  
Time Points ◽  
Post Transplant ◽  
Donor T Cells ◽  
Over Time

Abstract Donor T-lymphocytes are effective adoptive immunotherapy in the context of allogeneic hematopoietic stem cell transplantation (allo-HSCT), but life threatening complications related to GVHD limits its clinical application. Recent advancement in the field of immunotherapy has directed our interest to enhancing the anti-tumor response of donor T cells by modulating expression of checkpoint blockade molecules including programmed death-1 (PD-1), cytotoxic T-lymphocyte associated antigen-4 (CTLA-4) and foxp3, the transcription factor associated with regulatory T cells. The two ligands of PD-1, PD-L1 or PD-L2 are highly expressed in the presence of inflammatory signal induced by infection or cancer and PD-1/PD-L1 interaction negatively regulates T-cell antigen receptor (TCR) signaling and dampen T cell cytotoxic activity. Herein, we studied the role of PD-1, CTLA-4 and transcription factor foxp3 expressing donor CD4+ and CD8+ T cells in the development of GVHD. Methods: We have used two established allo-HSCT murine GvHD models. Lethally irradiated wild type (WT) B6, PD-L1 knock out (KO) B6 and PD-L2 KO B6 mice were transplanted with 2 x 106 splenic T cells and 2 x 106 T cell depleted bone marrow (TCD BM) cells from H-2Kdonors. Lethally irradiated CB6F1 recipients were similarly transplanted with splenocytes and TCD BM cells from B6 donors. Acute GvHD scores were determined by combining scores obtained from histological tissue sections and weight-loss, posture, activity, fur texture and skin integrity following standard published procedures. The activation status of donor T-cells and BM and host-derived non-T cells in GvHD target organs was analyzed by flow cytometry. Data from allo-HSCT recipients were compared with the respective data obtained from B6 à B6 syngenic HSCT (syn-HSCT) recipients. Serum cytokines were determined by Luminex assay. Results: PD-L1 KO B6 allo-HSCT recipients had significantly increased acute GvHD scores compared with WT B6 allo-HSCT recipients (p<0.0005) and B6 PD-L2 KO allo-HSCT recipients (p<0.0005) measured on day 8 after transplant. All PD-L1 KO allo-HSCT recipients died within 10 days post transplant while WT B6 and PD-L2 KO allo-HSCT recipients had 20% mortality until 36 days post transplant. Increased acute GvHD was associated with increased amount of serum inflammatory cytokines and increased numbers of activated PD-1+CD69+CD4+ donor T cells. Interestingly, PD-1 expression on donor CD4+ T cells significantly increased in the spleen of transplant recipients but not in BM, while PD-1 expression was significantly increased on donor CD8+ T cells in both spleen and BM compartments of allo-HSCT recipients compared with the syn-HSCT recipients. CTLA-4 expression on CD4+ and CD8+ donor T cells were significantly increased in spleen in the first two weeks post transplant but decreased at later time points compared with syn-HSCT. Again, CTLA-4 expression on CD4+ donor T cells in the BM remained significantly higher measured on 100+ days post transplant in allo-HSCT recipients compared with the syn-HSCT but similar levels of CTLA-4 expression on CD8+ T cells were measured in BM between these two HSCT recipients. Foxp3 expression on donor T cells and the numbers of CD4+CD25+foxp3+ regulatory T (Tregs) were markedly suppressed in donor T cells on day 4 post HSCT of allo-HSCT recipients compared with the syn-HSCT recipients. Although total numbers of donor T cells in the spleen of allo-HSCT recipients remained low over time, the percentage of PD-L1-expressing donor T cells in spleen were significantly higher (p<0.005) at early time points (day 4) in allo-HSCT recipients compared with the syn-HSCT. While total numbers of host-derived cells in spleen decreased over time in mice that developed GvHD, host-derived PD-L1 expressing CD3+ T cells persisted at higher levels through day 36 post transplant. Additionally, PD-L1 expression was also increased in donor BM-derived T cells and non-T cells populations over time. Collectively, these data indicate that severe GvHD occurs in allo-HSCT recipients in spite of increased numbers of PD-1, CTLA-4 and PD-L1 expressing donor and host cells. The occurrence of severe GvHD in these allo-HSCT models systems was associated with markedly reduced levels of CTLA-4 and foxp3 transcription factor expressing Tregs indicating that these pathways may be more relevant to controlling GvHD than PD-1:PD-L1 expression. Disclosures No relevant conflicts of interest to declare.

scholarly journals CD8+CD44hi but not CD4+CD44hi memory T cells mediate potent graft antilymphoma activity without GVHD

Blood ◽  
2011 ◽  
Vol 117 (11) ◽  
pp. 3230-3239 ◽  
Author(s):  
Suparna Dutt ◽  
Jeanette Baker ◽  
Holbrook E. Kohrt ◽  
Neeraja Kambham ◽  
Mrinmoy Sanyal ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Memory T Cells ◽  
Cell Subset ◽  
B Cell Lymphoma ◽  
Effector Memory ◽  
T Cell Subset ◽  
Progressive Growth

Abstract Allogeneic hematopoietic cell transplantation can be curative in patients with leukemia and lymphoma. However, progressive growth of malignant cells, relapse after transplantation, and graft-versus-host disease (GVHD) remain important problems. The goal of the current murine study was to select a freshly isolated donor T-cell subset for infusion that separates antilymphoma activity from GVHD, and to determine whether the selected subset could effectively prevent or treat progressive growth of a naturally occurring B-cell lymphoma (BCL1) without GVHD after recipients were given T cell–depleted bone marrow transplantations from major histocompatibility complex–mismatched donors. Lethal GVHD was observed when total T cells, naive CD4+ T cells, or naive CD8+ T cells were used. Memory CD4+CD44hi and CD8+CD44hi T cells containing both central and effector memory cells did not induce lethal GVHD, but only memory CD8+ T cells had potent antilymphoma activity and promoted complete chimerism. Infusion of CD8+ memory T cells after transplantation was able to eradicate the BCL1 lymphoma even after progressive growth without inducing severe GVHD. In conclusion, the memory CD8+ T-cell subset separated graft antilymphoma activity from GVHD more effectively than naive T cells, memory CD4+ T cells, or memory total T cells.

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