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Introduction: Peripheral blood stem cell (PBSC) donation is the primary procedure used to collect hematopoietic stem and progenitor cells (HSPCs) for hematopoietic stem cell transplantation. Single bouts of exercise transiently enrich peripheral blood with HSPCs and cytolytic natural killer cells (CD56dim), which are important in preventing post-transplant complications. To provide a rationale to investigate the utility of exercise in a PBSC donation setting (≈3 h), this study aimed to establish whether interval cycling increased peripheral blood HSPC and CD56dim concentrations to a greater degree than continuous cycling. Methods: In a randomised crossover study design, eleven males (mean ± SD: age 25 ± 7 years) undertook bouts of moderate intensity continuous exercise [MICE, 30 min, 65%-70% maximum heart rate (HRmax)], high-volume high intensity interval exercise (HV-HIIE, 4 × 4 min, 80%-85% HRmax) and low-volume HIIE (LV-HIIE, 4 × 2 min, 90%-95% HRmax). The cumulative impact of each interval on circulating HSPC (CD34+CD45dimSSClow) and CD56dim concentrations (cells/µL), and the bone marrow homing potential of HSPCs (expression of CXCR-4 and VLA-4) were determined. Results: There was an increase in HSPC concentration after two intervals of LV-HIIE (Rest: 1.84 ± 1.55 vs. Interval 2: 2.94 ± 1.34, P = 0.01) and three intervals of HV-HIIE only (Rest: 2.05 ± 0.86 vs. Interval 3: 2.51 ± 1.05, P = 0.04). The concentration of all leukocyte subsets increased after each trial, with this greatest for CD56dim NK cells, and in HIIE vs. MICE (LV-HIIE: 4.77 ± 2.82, HV-HIIE: 4.65 ± 2.06, MICE: 2.44 ± 0.77, P < 0.0001). These patterns were observed for concentration, not frequency of CXCR-4+ and VLA-4+ HSPCs, which was unaltered. There was a marginal decrease in VLA-4, but not CXCR-4 expression on exercise-mobilised HSPCs after all trials (P < 0.0001). Discussion: The results of the present study indicate that HIIE caused a more marked increase in HSPC and CD56dim NK cell concentrations than MICE, with mobilised HSPCs maintaining their bone marrow homing phenotype. LV-HIIE evoked an increase in HSPC concentration after just 2 × 2-minute intervals. The feasibility and clinical utility of interval cycling in a PBSC donation context should therefore be evaluated.
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Graft-versus-host disease (GvHD) remains a major challenge following allogeneic hematopoietic stem cell transplantation (allo-HSCT) and further understanding of its immunopathology is crucial for developing new treatments. CD70 interacts with CD27 and is upregulated transiently on T cells following recent TCR engagement. Here we investigated the functional and clinical significance of CD70 expression on T cells during the early post-transplantation period. CD70 was expressed on a subset of highly activated memory T cells within the first 2 weeks post-transplant which then gradually declined in most patients. CD70+ T cells exhibited an open chromatin landscape and a transcriptional profile indicative of intense MYC-driven glycolysis and proliferation. CD4+ and CD8+ CD70+ T cell number increased by 9-fold and 4-fold respectively during acute GvHD (aGvHD) and displayed an oligoclonal TCR repertoire. These cells expressed CCR4 and CCR6 chemokine receptors and were markedly increased in aGvHD tissue samples. Furthermore, CD70+ T cells demonstrated alloreactive specificity in vitro and proliferative and inflammatory cytokine responses were markedly attenuated by CD70 blockade. These findings identify CD70 as a marker of highly activated alloreactive T cells and reveal the potential therapeutic importance of inhibiting CD27-CD70 co-stimulation in both the prophylaxis and treatment of aGvHD.
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Células Asesinas Naturales , Leucemia Linfocítica Crónica de Células B , Receptor de Muerte Celular Programada 1 , Humanos , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Receptor de Muerte Celular Programada 1/metabolismo , Leucemia Linfocítica Crónica de Células B/metabolismo , Leucemia Linfocítica Crónica de Células B/patología , Leucemia Linfocítica Crónica de Células B/inmunologíaRESUMEN
Allogeneic stem cell transplantation is a centrally important curative strategy in adults with acute myeloid leukaemia; however, relapse occurs in a significant proportion of patients and remains the leading cause of treatment failure. The prognosis for patients who relapse post-transplant remains poor, and the development of new strategies with the ability to reduce disease recurrence without increasing transplant toxicity remains a priority. In this review, within the context of our understanding of disease biology and the graft-versus-leukaemia (GVL) effect, we will discuss established, evolving and novel approaches for increasing remission rates, decreasing measurable residual disease pretransplant, future methods to augment the GVL effect and the opportunities for post-transplant maintenance. Future progress depends upon the development of innovative trials and networks, which will ensure the rapid assessment of emerging therapies in prospective clinical trials.
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Trasplante de Células Madre Hematopoyéticas , Leucemia Mieloide Aguda , Trasplante Homólogo , Humanos , Leucemia Mieloide Aguda/terapia , Trasplante de Células Madre Hematopoyéticas/métodos , Recurrencia , Efecto Injerto vs Leucemia , Neoplasia ResidualRESUMEN
Allogeneic stem cell transplantation is used widely in the treatment of hematopoietic malignancy although graft versus host disease and relapse remain major complications. We measured the serum protein expression of 92 inflammation-related markers from 49 patients at Day 0 (D0) and 154 patients at Day 14 (D14) following transplantation and related values to subsequent clinical outcomes. Low levels of 7 proteins at D0 were linked to GvHD whilst high levels of 7 proteins were associated with relapse. The concentration of 38 proteins increased over 14 days and higher inflammatory response at D14 was strongly correlated with patient age. A marked increment in protein concentration during this period associated with GvHD but reduced risk of disease relapse, indicating a link with alloreactive immunity. In contrast, patients who demonstrated low dynamic elevation of inflammatory markers during the first 14 days were at increased risk of subsequent disease relapse. Multivariate time-to-event analysis revealed that high CCL23 at D14 was associative of AGvHD, CXCL10 with reduced rate of relapse, and high PD-L1 with reduced overall survival. This work identifies a dynamic pattern of inflammatory biomarkers in the very early post-transplantation period and reveals early protein markers that may help to guide patient management.
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Enfermedad Injerto contra Huésped , Trasplante de Células Madre Hematopoyéticas , Humanos , Pronóstico , Trasplante Homólogo/efectos adversos , Recurrencia Local de Neoplasia/complicaciones , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Enfermedad Crónica , RecurrenciaRESUMEN
PD-1 is expressed on exhausted T cells in cancer patients but its physiological role remains uncertain. We determined the phenotype, function and transcriptional correlates of PD-1 expression on cytomegalovirus-specific CD4+ T cells during latent infection. PD-1 expression ranged from 10-85% and remained stable over time within individual donors. This 'setpoint' was correlated with viral load at primary infection. PD-1+ CD4+ T cells display strong cytotoxic function but generate low levels of Th1 cytokines which is only partially reversed by PD-1 blockade. TCR clonotypes showed variable sharing between PD-1+ and PD-1- CMV-specific cells indicating that PD-1 status is defined either during T cell priming or subsequent clonal expansion. Physiological PD-1+ CD4+ T cells therefore display a unique 'high cytotoxicity-low cytokine' phenotype and may act to suppress viral reactivation whilst minimizing tissue inflammation. Improved understanding of the physiological role of PD-1 will help to delineate the mechanisms, and potential reversal, of PD-1+ CD4+ T cell exhaustion in patients with malignant disease.
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Linfocitos T CD4-Positivos/metabolismo , Citocinas/metabolismo , Infecciones por Citomegalovirus/virología , Citomegalovirus/patogenicidad , Receptor de Muerte Celular Programada 1/metabolismo , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Citocinas/inmunología , Citomegalovirus/metabolismo , Infecciones por Citomegalovirus/inmunología , Expresión Génica/inmunología , Humanos , Receptor de Muerte Celular Programada 1/inmunología , Carga Viral/inmunologíaRESUMEN
BACKGROUND: The importance of chimerism status in the very early period after hematopoietic stem cell transplantation is unclear. We determined PBMC and T-cell donor chimerism 50 days after transplantation and related this to disease relapse and overall survival. METHODS: 144 sequential patients underwent transplantation of which 90 had AML/MDS and 54 had lymphoma. 'Full donor chimerism' was defined as ≥99% donor cells and three patient groups were defined: 40% with full donor chimerism (FC) in both PBMC and T-cells; 25% with mixed chimerism (MC) within both compartments and 35% with 'split' chimerism (SC) characterised by full donor chimerism within PBMC and mixed chimerism within T-cells. RESULTS: In patients with myeloid disease a pattern of mixed chimerism (MC) was associated with a one year relapse rate of 45% and a five year overall survival of 40% compared to values of 8% and 75%, and 17% and 60%, for those with SC or FC respectively. The pattern of chimerism had no impact on clinical outcome for lymphoma. CONCLUSION: The pattern of lineage-specific chimerism at 50 days after transplantation is highly predictive of clinical outcome for patients with myeloid malignancy and may help to guide subsequent clinical management.
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Trasplante de Células Madre Hematopoyéticas , Leucemia Mieloide Aguda , Linfoma , Síndromes Mielodisplásicos , Linfocitos T/metabolismo , Quimera por Trasplante/sangre , Adulto , Anciano , Aloinjertos , Supervivencia sin Enfermedad , Femenino , Humanos , Leucemia Mieloide Aguda/sangre , Leucemia Mieloide Aguda/mortalidad , Leucemia Mieloide Aguda/terapia , Linfoma/sangre , Linfoma/mortalidad , Linfoma/terapia , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/sangre , Síndromes Mielodisplásicos/mortalidad , Síndromes Mielodisplásicos/terapia , Tasa de SupervivenciaRESUMEN
Transplantation is an effective treatment of many clinical disorders, but the mechanisms that regulate immunological tolerance are uncertain and remain central to improving patient outcome. Hemopoietic stem cell transplantation (SCT) often establishes "mixed chimerism" in which immune cells from both the donor and patient coexist in vivo in a setting of immunological tolerance. We studied immune function in 69 patients within 2 months following SCT; 37 were fully donor and 32 displayed mixed chimerism. The proportion of T regulatory (Treg) cells was increased during mixed chimerism and comprised equal numbers of donor and host-derived regulatory cells. This was associated with a tolerogenic PD-L1+ profile on dendritic cells. Importantly, effector T cells from patients with mixed chimerism exhibited reduced cytotoxicity against host target cells in vitro, but this was restored following depletion of CD4+ Treg cells. These data show that Treg cells play a major role in sustaining immunological tolerance during mixed chimerism. These insights should help to guide novel interventions to improve clinical transplantation.
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Quimerismo , Trasplante de Células Madre Hematopoyéticas , Linfocitos T Reguladores/inmunología , Antígeno B7-H1/metabolismo , Células Dendríticas/metabolismo , Reacción Injerto-Huésped/inmunología , Humanos , Tolerancia Inmunológica/inmunología , Linfocitos T Reguladores/citología , Donantes de Tejidos , Tolerancia al Trasplante/inmunologíaRESUMEN
A 46-year-old woman with a history of dasatinib-resistant chronic myeloid leukaemia, clonal evolution and monosomy 7 underwent reduced intensity conditioned in vivo T-cell-depleted allogeneic haematopoietic stem cell transplantation (HSCT) from a matched unrelated donor. Following the transplantation, she developed recurrent cutaneous graft versus host disease (GvHD), which required treatment with systemic immunosuppression and electrocorporeal photophoresis. Concurrently, she developed a lichenoid rash with granulomatous features suggestive of cutaneous sarcoidosis. Additional treatment with hydroxychloroquine was initially successful, but 2â months later, she developed erythroderma with palpable lymphadenopathy. Repeated histological analysis established a diagnosis of folliculotropic mycosis fungoides stage IVA2, and the malignant clone was confirmed to be of donor origin. A positive response to brentuximab has been shown. This is the first reported case of primary mycosis fungoides after matched unrelated donor HSCT, and in a patient still undergoing treatment for GvHD.
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Enfermedad Injerto contra Huésped/etiología , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Micosis Fungoide/etiología , Neoplasias Cutáneas/etiología , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Femenino , Enfermedad Injerto contra Huésped/terapia , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/terapia , Micosis Fungoide/tratamiento farmacológico , Neoplasias Cutáneas/tratamiento farmacológico , Quimera por Trasplante , Trasplante Homólogo/efectos adversos , Resultado del Tratamiento , Donante no EmparentadoRESUMEN
The thymus supports the production of self-tolerant T cells from immature precursors. Studying the mechanisms regulating the establishment and maintenance of stromal microenvironments within the thymus therefore is essential to our understanding of T-cell production and ultimately immune system functioning. Despite our ability to phenotypically define stromal cell compartments of the thymus, the mechanisms regulating their development and the ways by which they influence T-cell precursors are still unclear. Here, we review recent findings and highlight unresolved issues relating to the development and functioning of thymic stromal cells.