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This document is the product of a stellarator community workshop, organized by the National Stellarator Coordinating Committee and referred to as Stellcon, that was held in Cambridge, Massachusetts in February 2016, hosted by MIT. The workshop was widely advertised, and was attended by 40 scientists from 12 different institutions including national labs, universities and private industry, as well as a representative from the Department of Energy. The final section of this document describes areas of community wide consensus that were developed as a result of the discussions held at that workshop. Areas where further study would be helpful to generate a consensus path forward for the US stellarator program are also discussed. The program outlined in this document is directly responsive to many of the strategic priorities of FES as articulated in ''Fusion Energy Sciences: A Ten-Year Perspective (2015-2025)'' [1]. The natural disruption immunity of the stellarator directly addresses ''Elimination of transient events that can be deleterious to toroidal fusion plasma con- finement devices'' an area of critical importance for the US fusion energy sciences enterprise over the next decade. Another critical area of research ''Strengthening our partnerships with international research facilities,'' is being significantly advanced on the W7-X stellarator in Germany and serves as a test-bed for development of successful international collaboration on ITER. This report also outlines how materials science as it relates to plasma and fusion sciences, another critical research area, can be carried out effectively in a stellarator. Additionally, significant advances along two of the Research Directions outlined in the report; ''Burning Plasma Science: Foundations--Next-generation research capabilities'', and ''Burning Plasma Science: Long pulse--Sustainment of Long-Pulse Plasma Equilibria'' are proposed. [ABSTRACT FROM AUTHOR]

Lenalidomide (LEN) and metronomic cyclophosphamide (CTX) regulate angiogenesis and immunosuppressive cells linked to the progression of metastatic castration-resistant prostate cancer (mCRPC). A phase-I/II, dose-escalation trial of LEN plus oral CTX was conducted in patients with previously treated mCRPC. In the phase-I study, CTX was given at 50 mg (day 1-28) and LEN at 10-25 mg (day 1-21) on a 28-day cycle using a '3+3' study design. In phase II, patients received LEN at 25 mg (day 1-21) with CTX at 50 mg PO QD (day 1-28) on a 28-day cycle. Nineteen patients in phase I were evaluable for toxicity. The maximum tolerated dose (MTD) was not observed at any of the dose levels (DLs) tested. Six patients received treatment in phase II before the trial was closed. A ≥ 50 % reduction in PSA was observed in 31.7 % evaluable patients. Radiographically, one patient had a partial response. Stable disease was documented in 68 % of evaluable patients after two therapy cycles. Circulating tumor cells (CTCs) decreased in 22.7 % and remained stable in 31.8 % of patients. Baseline numbers of peripheral MDSCs (MDSC; Lin-DRCD11b) were significantly increased in patients versus normal donors, and were decreased by chemotherapy. At baseline, MDSCs correlated directly with CTCs, and inversely with T- and B cell frequency supporting their immunosuppressive activity. The combination of LEN and metronomic CTX can be safely administered, reversing cellular immunosuppression in this group of elderly patients with mCRPC. Further research is required to identify responsive subgroup(s) and validate the biomarkers. [ABSTRACT FROM AUTHOR]

Dendritic cell (DC) expansion is regulated by the hematopoietic growth factor fms-like tyrosine kinase 3 ligand (Flt3L). DCs are critical to the control of tumor growth and metastasis, and there is a positive correlation between intratumoral DC infiltration and clinical outcome. In this report, we first demonstrate that single intravenous (i.v.) injections of adenovirus (Adv)-Flt3L significantly increased splenic dendritic, B, T and natural killer (NK) cell numbers in both normal and mammary tumor-bearing mice. In contrast, the numbers of DCs and T cells infiltrating the tumors were not increased. Consistent with the minimal effect on immune cell infiltration, i.v. Adv-Flt3L injections had no therapeutic activity against orthotopic mammary tumors. In addition, we noted tumor and Adv-Flt3L expansion of Gr1+CD11b+ immature myeloid suppressor cells (IMSCs), which may inhibit the therapeutic efficacy of Adv-Flt3L-expanded DCs.Cancer Gene Therapy (2007) 14, 364–371. doi:10.1038/sj.cgt.7701018; published online 19 January 2007 [ABSTRACT FROM AUTHOR]

Fms-like tyrosine kinase (Flt3L) is a potent stimulator of hematopoietic progenitor cell (HPC) expansion and mobilization; however, this requires 7-10 days of administration. We investigated whether sustained delivery of Flt3L using a poloxamer-based matrix (PG) could accelerate and/or improve the hematopoietic activity of Flt3L in mice. A single injection of PG-Flt3L stimulated significantly more rapid and greater HPC mobilization to the spleen and peripheral blood than the daily injection of Flt3L formulated in saline. Pharmacokinetic analysis demonstrated that the formulation of Flt3L in PG prolonged its elimination (T?) half-life (2.3-fold) and increased its bioavailability (>two fold) and the time to maximum serum concentration (Tmax) (2.7-fold). Further, coadministration of G-CSF and PG-Flt3L allowed lower doses of Flt3L to be active, with significantly greater hematopoietic and mobilization activity, compared to the same total dose of G-CSF, Flt3L or G-CSF and Flt3L formulated in saline. These data demonstrate that formulation of Flt3L in PG significantly accelerates and increases HPC expansion and mobilization. The observation of increased bioactivity by PG-Flt3L in rodents suggests the potential for improved clinical efficacy of Flt3L by reducing the time required for HPC mobilization.Bone Marrow Transplantation (2003) 31, 361-369. doi:10.1038/sj.bmt.1703816 [ABSTRACT FROM AUTHOR]

A majority of patients with intermediate or high-grade non-Hodgkin’s lymphoma (NHL) who are treated with high-dose chemotherapy (HDT) and hematopoietic stem cell transplantation subsequently relapse. Until recently, transplantation was associated with high morbidity and mortality and the focus was on improving the safety of this procedure. However, the use of growth factors and other supportive measures has successfully reduced treatment mortality to less than 5%. Therefore, new strategies need to be developed to eliminate the growth of any occult tumor cells reinfused with the stem cell products and the tumor cells remaining in the patient. One approach is to improve the immune function of the patients by a more rapid immune reconstitution and augmentation of effector cell function. We report studies comparing immune recovery following HDT and autologous peripheral stem cell transplantation (PSCT) as compared to autologous bone marrow transplantation (ABMT). These studies examined patients with intermediate and high-grade non-Hodgkin’s lymphoma (NHL) who were treated with HDT and PSCT (n = 56) or ABMT (n = 60). The PSCT patients had a significantly faster recovery of circulating monocytes (CD14+ cells), natural killer ((NK) CD56+) cells, T helper (CD4+) cells, TCRγ/δ cells, and naive T lymphocytes (CD45RA+). Following ABMT there was a significantly more rapid increase in the frequency of T suppressor/effector (CD8+) cells, B (CD19+) cells, CD34+ cells, polymorphonuclear leukocytes (PMN) and memory T lymphocytes (CD45RO+). The CD4:CD8 and CD45RA:CD45RO ratios were consistently higher in the PSCT group as compared to ABMT suggesting an improved ratio of T helper to T effector/suppressor cells and naive T cells. The differences in cellular phenotype translated into improved T cell function (PHA mitogenesis) and T cell help (pokeweed mitogenesis). In... [ABSTRACT FROM AUTHOR]

CARN 750 (injectable acemannan) is a polydispersed β-(1,4)-linked acetylated mannan isolated from the Aloe barbadensis plant. It has multiple therapeutic properties including activity in wound repair and as a biological agent for the treatment of neoplasia in animals as well as the ability to activate macrophages. We report herein that CARN 750 directly or indirectly has significant hematoaugmenting properties. We observed that the subcutaneous administration of CARN 750 significantly increases splenic and peripheral blood cellularity, as well as hematopoietic progenitors in the spleen and bone marrow as determined by the interleukin-3-responsive colony-forming unit culture assay and the high-proliferative-potential colony-forming-cell (HPP-CFC) assay (a measure of primitive hematopoietic precursors) in myelosuppressed (7 Gy) CBL/6 mice. The greatest hematopoietic effect was observed following sublethal irradiation in mice receiving 1 mg CARN 750/animal, with less activity observed at higher or lower doses. Further, CARN 750, following daily injection, has activity equal to or greater than the injection of an optimal dose of granulocyte-colony-stimulating factor (G-CSF) in myelosuppressed mice. In this comparison, significantly greater activity was observed in the splenic and peripheral blood cellularity, and in the frequency and absolute number of splenic HPP-CFC as compared to the mice receiving G-CSF at 3 μg/animal. CARN 750, when administered to myelosuppressed animals. decreased the frequency of lymphocytes with a concomitant significant increase in the frequency of polymorphonuclear leukocytes (PMN). However, owing to the increased cellularity, a significant increase in the absolute number of PMN, lymphocytes, monocytes and platelets was observed, suggesting activity on multiple cell lineages. The latter is the primary difference in activity as compared to G-CSF which has activity predominantly on PMN. [ABSTRACT FROM AUTHOR]

Bestatin (ubenimex), an inhibitor of aminopeptidase, is an oral immunomodulator that binds to CD13 (aminopeptidase N) on macrophages/monocytes. To examine its immunomodulatory effect after high-dose therapy and autologous bone marrow transplantation (BMT), a dose-finding phase Ib trial was conducted with 30 Hodgkin's disease and non-Hodgkin's lymphoma patients who received no drug (control), 10 and 30 mg (low dose), or 90 and 180 mg (high dose) of bestatin daily for 60 days following autologous BMT. Bestatin administration was initiated when the absolute neutrophil count was greater than 250/mm3 on 2 consecutive days. The serum neopterin levels, an indicator of monocyte/macrophage activation, increased in the high-dose group compared to the control group (not significantly) and the low-dose group (significantly). Similarly, the colony-stimulating activity in the sera was significantly increased in the high-dose group compared to the control and low-dose groups. We also examined the expression of cell-surface markers on monocytes in these patients by fluorescent cytometry analysis. There was no significant difference either in the frequency or absolute number of monocytes (CD14) among the three groups at any time. However, a significant increase in the frequency of CD16(FcgRIII)-positive monocytes (a marker of activation) was observed in the high-dose group compared to controls from day 14 to day 60 after the start of bestatin administration. Further, the frequency of HLA-DR monocytes (another marker of activation) was significantly increased in the high-dose group. These results indicate that bestatin at higher doses (90 and 180 mg daily), but not lower doses, activates macrophages/monocytes, as demonstrated by phenotypic marker (HLA-DR and CD16) up-regulation, and this provides augmentation of neopterin and colony-stimulating activity in the serum of patients following autologous BMT. [ABSTRACT FROM AUTHOR]

Two clinical results of peripheral blood stem cell support are commonly considered: (1) the effect on hematopoietic recovery and (2) the effect on the underlying malignancy. The dynamics of hematopoietic recovery after autologous bone marrow transplantation and after autologous peripheral blood stem cell transplantation in a clinical setting are similar if no exogenous cytokines are administered and the peripheral stem cells are collected while their numbers are not deliberately increased (mobilised). If mobilized peripheral stem cells are transplanted, hematopoietic recovery is accelerated. In some circumstances, patients who receive peripheral stem cell transplantation may experience an improved progression-free survival after high-dose therapy when compared with similar patients who receive autologous bone marrow transplantation. Explanations for such a survival advantage might include (1) a lower likelihood of occult tumor cells capable of restoring disease in peripheral stem cell autograft products than in bone marrow harvests, (2) a greater number of cytotoxic effector cells capable of destroying occult tumor cells in the peripheral stem cell collections than in bone marrow harvests, and (3) a different and advantageous pattern of immunologic recovery following autologous peripheral stem cell transplant compared to autologous bone marrow transplant. [ABSTRACT FROM AUTHOR]

In these studies, we compared the phenotype, function, and expression of type 1, type 2, and monocyte-associated cytokine mRNA transcripts in autologous bone marrow (BM) and growth factor-mobilized peripheral blood stem cell (PSC) products. These studies demonstrate that lymphocytes and monocytes in stem cell products are abnormally activated, expressing significantly higher levels of interleukin (IL)-2, 4 and 10, interferon gamma (IFN-γ), and tumor necrosis factor alpha (TNF-α), but not IL-8, as compared to normal peripheral blood mononuclear cells (PBMC). In addition, the levels of IL-2, IL-10 and TNF-α are significantly higher in mobilized PSC as compared to BM products. The high cytokine levels are unexpected as T cell function in stem cell products is depressed. PSC products have high levels of T cell inhibitory activity, which directly correlates with IL-10 expression, both of which are mechanisms that might be involved in the immune dysfunction within stem cell products used for autologous stem cell transplantation. These data demonstrate that: (1) immune cells in autologous BM and PSC products are activated with the expression of high levels of type 1 and type 2 cytokines as well as monokines; (2) PSC products contain a high frequency of monocytes which mediate T cell inhibitory activity; and (3) despite the high levels of cytokine expression, T cell function in stem cell products is depressed. The significance of these immune abnormalities within stem cell products for myeloid and lymphoid recovery following autologous stem cell transplantation remains to be determined. [ABSTRACT FROM AUTHOR]

This study compares the immune properties of peripheral blood stem cell (PSC) products mobilized with different hematopoietic growth factors (HGFs) as well as apheresis products and peripheral blood leukocytes (PBL) from normal individuals. We found that monocytes in mobilized PSC products appear to inhibit T cell function independent of whether granulocyte colony- stimulating factor (G-CSF) or granulocyte–macrophage colony-stimulating factor (GM-CSF) was used for mobilization. In addition, the GF used to mobilize the stem cell product may be less important to the CD4:CD8 ratio than the extent of prior chemotherapy, as we found an inverse correlation between chemotherapy and the CD4:CD8 ratio. In other observations, all apheresis products, whether mobilized or unmobilized, contained significantly more monocytes compared to normal PBL. The mononuclear cells (MNC) from G-CSF or GM-CSF mobilized PSC products had a similar T cell phytohemagglutinin (PHA) mitogenic response that was significantly lower (P = 0.001 and P = 0.005, respectively) than non-mobilized apheresis products. We also examined the T cell inhibitor (TI) activity of the MNC from the PSC products for allogeneic lymphocyte proliferation and found that PSC products significantly reduced the proliferation of allogeneic PBL to PHA. A significant correlation (P = 0.001, r = 0.517) between the frequency of monocytes and TI activity also was observed. [ABSTRACT FROM AUTHOR]

Rapid immune reconstitution is observed following autologous peripheral blood stem cell transplantation (PSCT) as compared to autologous bone marrow transplantation (ABMT), although it is depressed compared to that observed in normal individuals. The immune dysfunction occurs despite the restoration of normal lymphoid cell numbers and may be associated with the immunologic characteristics of the infused peripheral blood stem cell (PSC) product. We report herein that the in vitro T cell proliferation and NK activity in PSC products of breast cancer patients are significantly increased following the removal of CD14+ monocytes (33 ± 2% of the PSC product) by carbonyl iron magnetic cell isolation (CI). In vitro expansion of PSC cells cultured for 7–21 days in the presence of interleukin-2 (IL-2) is also significantly increased by depletion of the phagocytic cells. The PHA and IL-2 mitogenic responses, as well as NK activity of the expanded cells, was also significantly increased by the depletion of the phagocytes. In summary, the depletion of phagocytic monocytes from PSC products restores the proliferative and functional properties of T and NK lymphocytes and may facilitate adoptive cellular therapy, as well as rapid immunologic reconstitution post-PSCT. [ABSTRACT FROM AUTHOR]

To determine the effect of growth factor mobilization on the expression of adhesion molecules, we compared CD34+ progenitor cell (PC) populations from steady-state bone marrow (BM) with granulocyte–macrophage colony-stimulating factor (GM-CSF)-mobilized apheresis products (peripheral blood stem cell (PSC)) using flow cytometry. To increase the accuracy of this analysis, CD34+ cells were enriched (MiniMACS) before cytometric analysis. A significantly lower expression of very late antigen-4 (VLA-4), leukocyte function antigen-1 (LFA-1) and LFA-3 were observed on PSC compared to BM CD34+ cells. In addition, significantly lower mean fluorescence intensity (MFI) of VLA-4, VLA-5, intercellular adhesion molecule-1 (ICAM-1), and sialyl LewisX were observed on PSC as compared to BM CD34+ cells. Significantly higher levels of L-selectin and CD44 expression were observed on PSC as compared to BM CD34+ cells based on frequency and MFI (P  0.05). In addition, the duration of GM-CSF administration or number of prior aphereses had no effect on adhesion molecule expression. These data suggest that decreased expression of adhesion molecules including VLA-4, LFA-1, ICAM-1 and LFA-3 play a role in PC mobilization. Based on these studies, we suggest that PC mobilization occurs as a stochastic process and is associated with the selection of CD34+ cells with low adhesion molecule expression. [ABSTRACT FROM AUTHOR]

The article comments on a study about the recovery of CD4+ T lymphocytes after allogeneic bone marrow (BM) transplantation. This recovery results to a significant decrease in transplant-related mortality based on a cohort of 758 BM allograft patients. It is also associated with a significant better clinical outcome like correlations with overall survival, non-relapse mortality and opportunistic infections.