Immunoregulatory networks in healthy adult allogeneic stem cell donors : Studies of peripheral hematopoietic stem cell donors and their recipients

Final outcome after allogeneic peripheral blood stem cell transplantation (PBSCT) is influenced by the high degrees of variation in disease and comorbidities among recipients, as well as the pre-and post-transplant handling of patients. Recent studies suggest that outcome is also influenced by donor heterogeneity, and the impact of G-CSF–induced immunomodulation on graft composition and post-transplant outcome is still not fully understood. In this exploratory study, we characterized healthy HLA-matched related donors with respect to 27 distinct circulating lymphoid subsets, and systemic levels of 39 soluble mediators and 641 metabolites during hematopoietic stem cell mobilization and collection. A high degree of variation among donors was detected. This heterogeneity was further increased during G-CSF treatment and apheresis through preferential enrichment of certain immune cell subsets, soluble mediators and metabolites both in the donors and the stem cell grafts. Bioinformatics analyses were used to identify donor G-CSF–induced systemic changes and revealed a distinct dichotomy in G-CSF immune cell mobilization response, with potential impacts on recipient outcome. Our findings show that the systemic G-CSF–induced mediator profile predicted stem cell yield, and graft mediator profile was dependent on apheresis device and correlated to graft leukocyte and platelet levels. Our overall results show that healthy stem cell donors are heterogeneous with regard to immunoregulation, and this heterogeneity is increased by G-CSF treatment and stem cell harvesting. Future clinical studies should further investigate how immunological donor characteristics influence outcome after allotransplantation and the possible implications for hematopoietic stem cell mobilization and collection.Doktorgradsavhandlin

Granulocyte colony-stimulating factor alters the systemic metabolomic profile in healthy donors

Introduction: Peripheral blood stem cells mobilized by granulocyte colony-stimulating factor (G-CSF) from healthy donors are commonly used for allogeneic stem cell transplantation. The effect of G-CSF administration on global serum metabolite profiles has not been investigated before. Objectives: This study aims to examine the systemic metabolomic profiles prior to and following administration of G-CSF in healthy adults. Methods: Blood samples were collected from 15 healthy stem cell donors prior to and after administration of G-CSF 10 µg/kg/day for 4 days. Using a non-targeted metabolomics approach, metabolite levels in serum were determined using ultrahigh performance liquid chromatography-tandem mass spectrometry and gas chromatography/mass spectrometry. Results: Comparison of the metabolite profiles of donors before and after G-CSF treatment revealed 239 metabolites that were significantly altered. The major changes of the metabolite profiles following G-CSF administration included alteration of several fatty acids, including increased levels of several medium and long-chain fatty acids, as well as polyunsaturated fatty acids; while there were lower levels of other lipid metabolites such as phospholipids, lysolipids, sphingolipids. Furthermore, there were significantly lower levels of several amino acids and/or their metabolites, including several amino acids with known immunoregulatory functions (methionine, tryptophan, valine). Lastly, the levels of several nucleotides and nucleotide metabolites (guanosine, adenosine, inosine) were also decreased after G-CSF administration, while methylated products were increased. Some of these altered products/metabolites may potentially have angioregulatory effects whereas others may suggest altered intracellular epigenetic regulation. Conclusion: Our results show that G-CSF treatment alters biochemical serum profiles, in particular amino acid, lipid and nucleotide metabolism. Additional studies are needed to further evaluate the relevance of these changes in healthy donors.publishedVersio

Impact of previous disease-modifying treatment on safety and efficacy in patients with MS treated with AHSCT

Background Autologous haematopoietic stem cell transplantation (AHSCT) is a highly effective treatment for multiple sclerosis (MS). The impact of previous long-lasting disease-modifying treatments (DMT) for safety and efficacy of AHSCT is unknown. Objective To explore whether previous DMTs with long-lasting effects on the immune system (anti-CD20 therapy, alemtuzumab and cladribine) affect treatment-related complications, long-term outcome and risk of new MS disease activity in patients treated with AHSCT. Methods Retrospective observational study of 104 relapsing remitting patients with MS treated by AHSCT in Sweden and Norway from 2011 to 2021, grouped according to the last DMT used ≤6 months prior to AHSCT. The primary outcomes were early AHSCT-related complications (mortality, neutropenic fever and hospitalisation length), long-term complications (secondary autoimmunity) and proportion of patients with No Evidence of Disease Activity (NEDA-3 status): no new relapses, no MRI activity and no disease progression during the follow-up. Results The mean follow-up time was 39.5 months (range 1–95). Neutropenic fever was a common AHSCT-related complication affecting 69 (66%) patients. There was no treatment-related mortality. During the follow-up period, 20 patients (19%) were diagnosed with autoimmunity. Occurrence of neutropenic fever, hospitalisation length or secondary autoimmunity did not vary dependent on the last DMT used prior to AHSCT. A total of 84 patients (81%) achieved NEDA-3 status, including all patients (100%) using rituximab, alemtuzumab or cladribine before AHSCT. Conclusion This study provides level 4 evidence that AHSCT in patients previously treated with alemtuzumab, cladribine or rituximab is safe and efficacious.publishedVersio

A phase I prospective, non-randomized trial of autologous dendritic cell-based cryoimmunotherapy in patients with metastatic castration-resistant prostate cancer

Metastatic castration-resistant prostate cancer (mCRPC) is an immunologically cold disease with dismal outcomes. Cryoablation destroys cancer tissue, releases tumor-associated antigens and creates a pro-inflammatory microenvironment, while dendritic cells (DCs) activate immune responses through processing of antigens. Immunotherapy combinations could enhance the anti-tumor efficacy. This open-label, single-arm, single-center phase I trial determined the safety and tolerability of combining cryoablation and autologous immature DC, without and with checkpoint inhibitors. Immune responses and clinical outcomes were evaluated. Patients with mCRPC, confirmed metastases and intact prostate gland were included. The first participants underwent prostate cryoablation with intratumoral injection of autologous DCs in a 3 + 3 design. In the second part, patients received cryoablation, the highest acceptable DC dose, and checkpoint inhibition with either ipilimumab or pembrolizumab. Sequentially collected information on adverse events, quality of life, blood values and images were analyzed by standard descriptive statistics. Neither dose-limiting toxicities nor adverse events > grade 3 were observed in the 18 participants. Results indicate antitumor activity through altered T cell receptor repertoires, and 33% durable (> 46 weeks) clinical benefit with median 40.7 months overall survival. Post-treatment pain and fatigue were associated with circulating tumor cell (CTC) presence at inclusion, while CTC responses correlated with clinical outcomes. This trial demonstrates that cryoimmunotherapy in mCRPC is safe and well tolerated, also for the highest DC dose (2.0 × 108) combined with checkpoint inhibitors. Further studies focusing on the biologic indications of antitumor activity and immune system activation could be considered through a phase II trial focusing on treatment responses and immunologic biomarkers.publishedVersio

Immunoregulatory networks in healthy adult allogeneic stem cell donors : Studies of peripheral hematopoietic stem cell donors and their recipients

Final outcome after allogeneic peripheral blood stem cell transplantation (PBSCT) is influenced by the high degrees of variation in disease and comorbidities among recipients, as well as the pre-and post-transplant handling of patients. Recent studies suggest that outcome is also influenced by donor heterogeneity, and the impact of G-CSF–induced immunomodulation on graft composition and post-transplant outcome is still not fully understood. In this exploratory study, we characterized healthy HLA-matched related donors with respect to 27 distinct circulating lymphoid subsets, and systemic levels of 39 soluble mediators and 641 metabolites during hematopoietic stem cell mobilization and collection. A high degree of variation among donors was detected. This heterogeneity was further increased during G-CSF treatment and apheresis through preferential enrichment of certain immune cell subsets, soluble mediators and metabolites both in the donors and the stem cell grafts. Bioinformatics analyses were used to identify donor G-CSF–induced systemic changes and revealed a distinct dichotomy in G-CSF immune cell mobilization response, with potential impacts on recipient outcome. Our findings show that the systemic G-CSF–induced mediator profile predicted stem cell yield, and graft mediator profile was dependent on apheresis device and correlated to graft leukocyte and platelet levels. Our overall results show that healthy stem cell donors are heterogeneous with regard to immunoregulation, and this heterogeneity is increased by G-CSF treatment and stem cell harvesting. Future clinical studies should further investigate how immunological donor characteristics influence outcome after allotransplantation and the possible implications for hematopoietic stem cell mobilization and collection

Granulocyte colony-stimulating factor alters the systemic metabolomic profile in healthy donors

Introduction: Peripheral blood stem cells mobilized by granulocyte colony-stimulating factor (G-CSF) from healthy donors are commonly used for allogeneic stem cell transplantation. The effect of G-CSF administration on global serum metabolite profiles has not been investigated before. Objectives: This study aims to examine the systemic metabolomic profiles prior to and following administration of G-CSF in healthy adults. Methods: Blood samples were collected from 15 healthy stem cell donors prior to and after administration of G-CSF 10 µg/kg/day for 4 days. Using a non-targeted metabolomics approach, metabolite levels in serum were determined using ultrahigh performance liquid chromatography-tandem mass spectrometry and gas chromatography/mass spectrometry. Results: Comparison of the metabolite profiles of donors before and after G-CSF treatment revealed 239 metabolites that were significantly altered. The major changes of the metabolite profiles following G-CSF administration included alteration of several fatty acids, including increased levels of several medium and long-chain fatty acids, as well as polyunsaturated fatty acids; while there were lower levels of other lipid metabolites such as phospholipids, lysolipids, sphingolipids. Furthermore, there were significantly lower levels of several amino acids and/or their metabolites, including several amino acids with known immunoregulatory functions (methionine, tryptophan, valine). Lastly, the levels of several nucleotides and nucleotide metabolites (guanosine, adenosine, inosine) were also decreased after G-CSF administration, while methylated products were increased. Some of these altered products/metabolites may potentially have angioregulatory effects whereas others may suggest altered intracellular epigenetic regulation. Conclusion: Our results show that G-CSF treatment alters biochemical serum profiles, in particular amino acid, lipid and nucleotide metabolism. Additional studies are needed to further evaluate the relevance of these changes in healthy donors

Peripheral Blood Stem Cell Mobilization in Healthy Donors by Granulocyte Colony-Stimulating Factor Causes Preferential Mobilization of Lymphocyte Subsets

BackgroundAllogeneic hematopoietic stem cell transplantation is associated with a high risk of immune-mediated post-transplant complications. Graft depletion of immunocompetent cell subsets is regarded as a possible strategy to reduce this risk without reducing antileukemic immune reactivity.Study design and methodsWe investigated the effect of hematopoietic stem cell mobilization with granulocyte colony-stimulating factor (G-CSF) on peripheral blood and stem cell graft levels of various T, B, and NK cell subsets in healthy donors. The results from flow cytometric cell quantification were examined by bioinformatics analyses.ResultsThe G-CSF-induced mobilization of lymphocytes was a non-random process with preferential mobilization of naïve CD4+ and CD8+ T cells together with T cell receptor αβ+ T cells, naïve T regulatory cells, type 1 T regulatory cells, mature and memory B cells, and cytokine-producing NK cells. Analysis of circulating lymphoid cell capacity to release various cytokines (IFNγ, IL10, TGFβ, IL4, IL9, IL17, and IL22) showed preferential mobilization of IL10 releasing CD4+ T cells and CD3−19− cells. During G-CSF treatment, the healthy donors formed two subsets with generally strong and weaker mobilization of immunocompetent cells, respectively; hence the donors differed in their G-CSF responsiveness with regard to mobilization of immunocompetent cells. The different responsiveness was not reflected in the graft levels of various immunocompetent cell subsets. Furthermore, differences in donor G-CSF responsiveness were associated with time until platelet engraftment. Finally, strong G-CSF-induced mobilization of various T cell subsets seemed to increase the risk of recipient acute graft versus host disease, and this was independent of the graft T cell levels.ConclusionHealthy donors differ in their G-CSF responsiveness and preferential mobilization of immunocompetent cells. This difference seems to influence post-transplant recipient outcomes

Peripheral blood stem cell mobilization in healthy Donors by granulocyte colony-stimulating factor causes preferential mobilization of lymphocyte subsets

Background: Allogeneic hematopoietic stem cell transplantation is associated with a high risk of immune-mediated post-transplant complications. Graft depletion of immunocompetent cell subsets is regarded as a possible strategy to reduce this risk without reducing antileukemic immune reactivity. Study design and methods: We investigated the effect of hematopoietic stem cell mobilization with granulocyte colony-stimulating factor (G-CSF) on peripheral blood and stem cell graft levels of various T, B, and NK cell subsets in healthy donors. The results from flow cytometric cell quantification were examined by bioinformatics analyses. Results: The G-CSF-induced mobilization of lymphocytes was a non-random process with preferential mobilization of naïve CD4+ and CD8+ T cells together with T cell receptor αβ+ T cells, naïve T regulatory cells, type 1 T regulatory cells, mature and memory B cells, and cytokine-producing NK cells. Analysis of circulating lymphoid cell capacity to release various cytokines (IFNγ, IL10, TGFβ, IL4, IL9, IL17, and IL22) showed preferential mobilization of IL10 releasing CD4+ T cells and CD3−19− cells. During G-CSF treatment, the healthy donors formed two subsets with generally strong and weaker mobilization of immunocompetent cells, respectively; hence the donors differed in their G-CSF responsiveness with regard to mobilization of immunocompetent cells. The different responsiveness was not reflected in the graft levels of various immunocompetent cell subsets. Furthermore, differences in donor G-CSF responsiveness were associated with time until platelet engraftment. Finally, strong G-CSF-induced mobilization of various T cell subsets seemed to increase the risk of recipient acute graft versus host disease, and this was independent of the graft T cell levels. Conclusion: Healthy donors differ in their G-CSF responsiveness and preferential mobilization of immunocompetent cells. This difference seems to influence post-transplant recipient outcomes

Peripheral Blood Stem Cell Mobilization in Healthy Donors by Granulocyte Colony-Stimulating Factor Causes Preferential Mobilization of Lymphocyte Subsets

Background: Allogeneic hematopoietic stem cell transplantation is associated with a high risk of immune-mediated post-transplant complications. Graft depletion of immunocompetent cell subsets is regarded as a possible strategy to reduce this risk without reducing antileukemic immune reactivity. Study design and methods: We investigated the effect of hematopoietic stem cell mobilization with granulocyte colony-stimulating factor (G-CSF) on peripheral blood and stem cell graft levels of various T, B, and NK cell subsets in healthy donors. The results from flow cytometric cell quantification were examined by bioinformatics analyses. Results: The G-CSF-induced mobilization of lymphocytes was a non-random process with preferential mobilization of naïve CD4+ and CD8+ T cells together with T cell receptor αβ+ T cells, naïve T regulatory cells, type 1 T regulatory cells, mature and memory B cells, and cytokine-producing NK cells. Analysis of circulating lymphoid cell capacity to release various cytokines (IFNγ, IL10, TGFβ, IL4, IL9, IL17, and IL22) showed preferential mobilization of IL10 releasing CD4+ T cells and CD3−19− cells. During G-CSF treatment, the healthy donors formed two subsets with generally strong and weaker mobilization of immunocompetent cells, respectively; hence the donors differed in their G-CSF responsiveness with regard to mobilization of immunocompetent cells. The different responsiveness was not reflected in the graft levels of various immunocompetent cell subsets. Furthermore, differences in donor G-CSF responsiveness were associated with time until platelet engraftment. Finally, strong G-CSF-induced mobilization of various T cell subsets seemed to increase the risk of recipient acute graft versus host disease, and this was independent of the graft T cell levels. Conclusion: Healthy donors differ in their G-CSF responsiveness and preferential mobilization of immunocompetent cells. This difference seems to influence post-transplant recipient outcomes.publishedVersio