bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multipotent Adult Progenitor Cells (MAPC) Are Immunoprivileged and Demonstrate Immunosuppressive Properties on Activated T Cell Population.
Authors: Kovacsovics-Bankowski Magdalena , Streeter Philip R. , Hewett Erin , Van’t Hof Wouter J. , Deans Robert J. , Maziarz Richard T. 
Published: April 2020

Abstract
Multipotent Adult Progenitor cells (MAPC) are rare progenitor cells present within the bone marrow that have the capacity to differentiate into mesodermal, endodermal and ectodermal lineage cells. The capacity to differentiate into these diverse cell types distinguishes MAPC from Mesenchymal Stem Cells (MSC), and suggests that MAPC may provide biological solutions for tissue repair or regeneration in multiple organ systems (Jiang Y et al. Nature.2002; 418:41–9). We have developed the technology for the large-scale expansion of MAPC with stable phenotype and biological properties. Cell surface marker analysis of MAPC revealed that these cells express low levels of MHC class I, CD44, CD90 and CD49c and are negative for MHC class II, CD45 and CD106 suggesting that MAPC do not express markers associated with the hematopoietic lineage. However, to optimize in vivo utilization, the identification of MAPC immunological properties is necessary. The objectives of the current studies were 1) to determine the immunogenicity of MAPC and 2) to assess the immunomodulatory properties of MAPC. First, MAPC from two different rat strains did not stimulate allogeneic T cells proliferation, while splenocytes of the same rat strains elicited strong proliferative responses in a mixed lymphocytic culture. Second, the immunosuppressive properties of MAPC were investigated using alloactivated T cells. Addition of MAPC at the initiation of a mixed lymphocyte reactions (MLR) suppressed T cell proliferation in a dose dependent manner. The inhibition was detectable at as low as 3,000 MAPC/well. Lymphocyte proliferation in MAPC-containing cultures was inhibited by up to 80% when compared to cultures without MAPC. The ability to inhibit T cell alloresponses was independent of the MHC, allowing the use of “third party” MAPC as inhibitory cells. MAPC also inhibited proliferative responses to the T cell mitogen Concanavalin A (50%), although inhibition required higher MAPC:responder cell ratios. Taken together, these data suggest that MAPC are progenitor cells that do not express markers of the hematopoietic lineage; they are non-immunogenic, suggesting that universal MAPC donors may be used for tissue repair or regeneration; and MAPC exhibit potent immunosuppressive properties, a result which suggests that these calls may be useful in the management and/or prevention of GVHD.
Multi-Tissue Homing of Repopulating Hematopoietic Cells after Bone Marrow Transplantation in Mice.
Authors: Bistrian Roxana , Martin Hans , Seifried Erhard , Mueller Albrecht , Henschler Reinhard 
Published: April 2020

Abstract
We wished to assess the tissue distribution of repopulating hematopoietic stem cells after bone marrow transplantation (BMT), since so far only sub-fractions of repopulating cells have been found to home to hematopoietic organs and tissues in BMT models. Two x 105 lineage depleted (lin−) bone marrow cells from C57BL/6 Ly5.1 mice were transplanted into 2 x 5.5 Gy irradiated Ly5.2 congenic C57BL/6 recipient mice. On day 1, 7 or 28 post BMT, cell suspensions were prepared from bone marrow, spleen, muscle, brain, lung and liver, and CD45+ cells were enriched by magnetic beads separation. Enriched CD45+ cells from brain, quadriceps muscle, or other organs and tissues were transplanted into Ly5.2 secondary recipients in groups of three (mean transplanted cell number per mouse: 0.68 x 105; range: 0.26–2.9 x 105) along with 1 x 106 freshly isolated Ly5.2 competitor whole bone marrow cells. A total of 39 primary and 273 secondary recipient mice were analyzed. Here we show that whereas bone marrow displayed substantial donor-derived repopulation potential in non-irradiated and non-transplanted controls (mean contribution of Ly5.1 cells to bone marrow of secondary recipients after 4–7 weeks: 23.5%), muscle, brain, lungs and liver showed little competitive repopulating activity (&lt;2%). In transplanted recipients, however, high donor-derived repopulating activity was detected in bone marrow (38–72%), spleen (7–15%) and, surprisingly, in liver (25–36%), muscle (24–37%), brain (7–14%) and lung (4–12%) at 1, 7 and 28 days post BMT. In contrast, hematopoietic colony-forming cells localized exclusively to hematopoietic tissues and were not found in muscle, brain, or lung. Repopulation potential was present in blood in all groups including non-irradiated, non-transplanted controls (donor contribution, 6–20%). Our data indicate that, following BMT, bone marrow, spleen and additional tissues take up substantial numbers of repopulating cells. This provides an explanation for the published low homing efficiency of repopulating cells to hematopoietic organs.
Molecular Mechanisms of the AICD Paradoxon in Human T Cells Revealed by an Apototic Role for CD25.
Authors: Richter Guenther , Hanewinkel Karin , Mollweide Andreas , Burdach Stefan 
Published: April 2020

Abstract
The IL2R is a heterotrimeric receptor consisting of the alpha-chain (CD25) and the two signal transducing beta-, gamma-chains. CD25 monoclonal antibody (e.g. daclizumab) binding to the α-chain, blocks high affinity IL2 binding thereby preventing complete T cell activation. This opportunity to hinder T cell triggering is of ample importance in transplantation medicine and the treatment of autoimmune disease; e.g. for the prevention of an acute graft versus host reaction during allogeneic hematopoietic cell transplantation. However, gene-targeting experiments revealed, that CD25 has an important role in mediating activation induced cell death (AICD) thereby maintaining T cell homeostasis. Thus, CD25 antibodies may not only block T cell activation but may also prevent AICD attributing a dual function to IL2, which has been described by the term AICD paradoxon. The molecular mechanisms of AICD remain to be elucidated. In this study, the modulation of the genomic expression profile of human peripheral blood mononuclear cells (PBMC) with therapeutic concentrations of CD25 mAb was investigated with the aim to identify genes that are involved in T cell activation or in AICD. PBMC were stimulated with OKT3 together with recombinant IL2 in the absence or presence of 30 microgram/ml Daclizumab. Cells were incubated for 16 hrs, RNA extracted and subjected to microarray analysis on U133A gene chips (Affymetrix). Gene chip profile revealed up-regulation of 60 genes and down regulation of 36 genes respectively, by Daclizumab. Anti-CD25 treatment inhibitied cytokine genes typically expressed during T cell activation including CD40L, IL9, TNF-alpha and IFN-gamma as previously shown (e.g. Burdach et al., JCI). Surprisingly, daclizumab also blocked expression of several genes important for susceptibility to apoptosis, such as DR6. In addition, daclizumab reversed IL2-mediated repression of anti-apoptotic genes, such as TOSO. Microarray analysis of these apoptosis related genes was confirmed by RT-PCR and functional assays. In conclusion, CD25-mediated induction of pro-apoptotic as well as repression of anti-apoptotic gene clusters should be considered for future drug development of CD25-antibodies in the clinical arena: these apoptosis related gene products may represent new pharmacologic targets in hematopoietic cell transplantation as well as in the treatment of autoimmune diseases.
Effective Ex Vivo-Generation and Quantification of Leukemia-Derived DC Has To Precede a Specific T-Cell Stimulation for Adoptive Immunotherapy in AML and MDS.
Authors: Schmetzer Helga Maria , Kremser Andreas , Loibl Julia , Hentschel Nina , Steiner Karin , Schmid Christoph , Kroell Tanja , Kufner Stefanie , Salih Helmut , Valle Francesco del , Doehner Constanze , Schweiger Claudia , Schwartz Christian , Hiddemann Wolfgang , Kolb Hans-Jochen 
Published: April 2020

Abstract
The presentation of leukemic antigens can be improved in AML and MDS by in vitro conversion of leukemic cells in leukemia-derived DC (DCleu), thereby forming a platform for the generation of leukemia-specific cytotoxic lymphocytes (CTL). In preliminary analyses we could already define optimal serum-free culture conditions, generate and characterize DC from 55 MDS- and 99 AML-cases and characterize their T-cell activating function (Kufner S. 2005 I-III). DC/DCleu were quantified according to their surface DC /blast -marker profiles. However in 6/30% of cases with AML/MDS less than 10% of DC could be generated and only 50–60% of leukemic cells were convertible to DCleu. Therefore we tested 5 alternative methods to improve the harvest of DC/DCleu in 99 AML and 55 MDS-patients (1) ‘MCM-mimic’ (Lee, 2003), 2) ‘Ca-Ionophore’ (Houtenbos, 2003), 3) ‘Picibanil’ (Sato, 2003), 4) ‘Cytokines’ (Westers, 2003) and 5) ‘Poly I:C’ (Rouas, 2004)). 1. Although the percentual harvest of DC/DCleu was comparable in all of the methods (28–40% DC, with 45–65% of those DC being DCleu and about 47% of blasts being convertible to DCleu) not every method was successful in individual patients. 2. However we could demonstrate that DC can be generated from every sample with at least one of the following methods: MCM-mimic, Ca-Ionophore and Picibanil. 3. Highest DC/DCleu yield was seen in monocytoid differentiated FAB-types and was independent of the cytogenetic risk. 4. Many ‘DC-surface markers’ can be aready expressed on naive blasts in AML/MDS-patients before there conversion to DCleu. Moreover the ‘DC-marker expression’ is variable in individual patients and culture methods.
In summary our data show 1. that the generation of DC/DCleu is possible independent from the karyotype in every patient under serum-free conditions with at least one of the 3 methods MCM-mimic, Ca-Ionophore and Picibanil. 2. The overall percentual harvest of DCleu from MNC-fractions after culture in the 5 methods compared is low. Possibly a combination of the optimal method with optimal ‘DC- and blast markers’ in every single case could improve the detectability and quantification of DC/DCleu and residual blasts. This contributes to improve the generability and quality of DCleu to stimulate and expand anti-leukemia-directed T-cells for the immunotherapy of AML and MDS.
IL10-Transduced Mesenchymal Stem Cells Attenuate Experimental Acute Graft-Versus-Host Disease.
Authors: Min Chang-Ki , Kim Bo-Kyung , Park Gyeongsin , Cho Bin , Oh Il-Hoan 
Published: April 2020

Abstract
Recent data suggest that, due to their immunosuppressive nature, adult mesenchymal stem cells (MSCs) may be of interest to enhance allogeneic hematopoietic engraftment and prevent graft-versus-host disease (GVHD).
Using a murine model of acute GVHD, this study investigated whether the immunosuppressive properties of MSCs could reduce the severity of experimental GVHD. In a MHC-mismatched C57BL/6→B6D2F1 model, recipient animals were transplanted with bone marrow (BM) cells (10x106) plus 20x106 splenocytes after 1100 cGy on day 0. Various doses (1~3x106) of donor BM-derived MSCs were given intravenously from day 1 to day 5 and subsequently evaluated the clinical and immunologic parameters.
MSCs did not attenuate the severity of acute GVHD. Using GFP expressing MSCs, we were unable to detect labeled cells in liver, spleen, lymph nodes and lung day 7 post-BMT. Because MSCs fail to display any immunosuppression in this experimental GVHD model and induce an immunosuppressive microenvironment through the production of IL10, we investigated whether the use of genetically modified MSCs expressing IL10 (IL10-transduced MSCs, IL10 MSCs) could improve the GVHD protection. Lethally irradiated recipients were transplanted and injected with 2x106 IL10 MSCs, MSC expressing MIG as a vector (MIG MSCs), or diluent on day 1. Compared with MIG MSCs or controls, recipients of IL10 MSCs demonstrated significantly reduced mortality at day 50 after BMT (percent survival, 0% or 10% vs 70%, P&lt;0.001). The reduction in mortality was confirmed by the semi-quantitative GVHD score (P&lt;0.01). It was associated with decreased serum levels of pro-inflammatory cytokines, IFNγ on day 7 (IL10 MSCs vs MIG MSCs; 297±116 pg/ml vs 681±87 pg/ml, P=0.015). Serum levels of TNFα or splenic donor CD3+ cell numbers were not different between the groups. Thus, benefical effects on GVHD could be observed when MSCs were engineered to express an anti-inflammatory cytokine, IL10. The mechanisms for the GVHD protection effect of IL10 MSCs in this murine model are currently under investigation.
Human T Lymphocyte Activation Kinetics for Identifying and Targeting Alloreactive T Cells.
Authors: Bajwa Rajinder P.S. , McCarthy Philip L. , Wallace Paul K. , Wallace Stephen , Wu Yiyuan , Battiwalla Minoo 
Published: April 2020

Abstract
Selective depletion of alloreactive T cells from a stem cell graft has the potential of reducing graft versus host disease (GvHD) while preserving graft versus malignancy and third party responses. For this purpose several techniques generate and deplete alloreactive cells, which are donor-derived T cells activated by recipient tissue. The kinetics of T cell activation in donor-recipient co-culture systems is critical in optimizing the timing of depletion of alloreactive T cells. We present the T cell activation kinetics in our preclinical system. Peripheral blood mononuclear cells (PBMCs) were derived from several pairs of unrelated healthy human volunteers. 2500 cGy irradiated cells (stimulators) were co-cultured with PBMCs (responders) in a 1:1 ratio and a concentration of 5 x 106/ml in serum free medium. Stimulator cells were labeled with PKH67 and the co-cultures were, analyzed for CD3, CD4, and CD25, expression by flow cytometry on days 0 through 7, using Topro-3 to exclude dead cells. We also added low dose Interleukin-2 (IL2) for augmenting the generation of alloreactive cells, to see if this made a difference. Our results show that alloreactive CD8 cells (CD3+, CD4−, CD25+) increased from ≤1 % on day 0, to 6.5 percent by day 5; the addition of IL2 amplified this to nearly 10% by day 5. CD4 + activated T cells (CD3+, CD4+, CD25+dim or total) did not appreciably increase over time and ranged between 2 to 5%; the addition of IL2 did not have any effect. T regulatory cells (CD3+, CD4+, CD25+bright) increased from ≤1 percent at baseline to 5% by day 5 and these were unaffected by the addition of IL2. The proportion of non-activated T lymphocytes, decreased with time of co-culture progression. Our results show that T lymphocyte activation, defined by CD25 expression, progressively increases through the first week of co-culture. This important observation will help in establishing the timing of allograft manipulation, for the selective depletion of alloreactive T cells in clinical hematopoietic stem cell transplantation.
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Therapeutic Anti-Tumor Immunity Mediated by Transiently Engrafting Allogeneic Lymphocytes: The “Allogeneic Effect” Revisited.
Authors: Symons Heather J. , Levy M. Yair , Wang Jie , Zhou Xiaotao , Fuchs Ephraim J. 
Published: April 2020

Abstract
The “allogeneic effect” refers to the induction of host B cell antibody synthesis or host T cell cytotoxicity, including tumoricidal activity, by an infusion of allogeneic lymphocytes. We have previously shown that treatment of mice with cyclophosphamide (Cy) followed by infusion of CD8+ T cell-depleted allogeneic spleen cells (Cy + CD8− DLI) induces anti-tumor activity in a model of minimal residual leukemia, even though the donor cells are eventually rejected by the host immune system. The purpose of the current investigation was to test the activity of Cy + CD8− DLI in the treatment of well-established cancer, and to characterize the mechanisms of the anti-tumor effect. BALB/c mice were inoculated intravenously (IV) with the syngeneic A20 lymphoma/leukemia or the RENCA renal cell carcinoma on day 0 and were then treated with nothing, Cy alone on day 14, or Cy + CD8− DLI from MHC-mismatched C57BL/6 donors on day 15. In both tumor models, the combination of Cy + CD8− DLI significantly prolonged survival compared to mice treated with nothing or with Cy alone. While depletion of CD4+ T cells from the DLI significantly diminished the beneficial effect of CD8− DLI, purified CD4+ T cells alone were inactive, demonstrating that donor CD4+ T cells and another population of cells were required for optimal anti-tumor activity. Several observations pointed to an active role for the host immune system in the anti-tumor activity of Cy + CD8− DLI. First, host T cells participated in the anti-tumor effect of treatment with Cy alone, since the drug’s activity was diminished in tumor-bearing scid mice or in normal BALB/c mice depleted of T cells. Second, while Cy + CD8− DLI caused no GVHD in tumor-bearing but immunocompetent BALB/c recipients, it caused fatal acute GVHD in either tumor-bearing scid or T-cell depleted BALB/c mice. Finally, the anti-tumor effect of Cy + CD8- DLI was also significantly inhibited in BALB/c mice that were depleted of CD8+ T cells. These results demonstrate that transiently engrafting T cells administered after Cy can induce significant anti-tumor effects against both solid and liquid tumors. We propose that upon recognition of alloantigen on host antigen-presenting cells (APCs), allogeneic donor CD4+ T cells deliver activating ligands to the APCs, thereby generating effective “help” to break tolerance in tumor-specific host CD8+ T cells. This mechanism may correspond to the “allogeneic effect” in the anti-tumor response described over three decades ago.
Comparing Platelet Loss in 2 Common Apheresis Machines for Collecting Autologous Peripheral Blood Stem Cells (PBSC).
Authors: Law Ping , Yasir Fathalha , Mah Joanna K.Y. , Soh Teck Guan , Lim Susan T.T. , Tan Lip Kun 
Published: April 2020

Abstract
Chemotherapy together with G-CSF is commonly used to mobilize patients prior to leukapheresis (LP) of PBSC for autologous transplantation. For many patients, peripheral blood platelet counts (PLT) were below 75,000/μl when LP was initiated. Minimizing PLT loss is an important consideration, especially for these patients. The aim of this retrospective analysis is to compare PLT loss during LP for autologous PBSC in two common apheresis machines (Baxter Amicus and Cobe Spectra). Between August 2004 and May 2005, 57 autologous PBSC products were collected from 28 adult patients (weight &gt; 40 kg) with results (mean ± SD) summarized in Table 1. LP were collected using automated procedures and 3 times blood volume was processed. Collection efficiencies (EFF) were calculated as total cells (CD34+ or PLT) in product divided by the circulating count prior to LP times processed volume. Statistical significance was determined by unpaired Student’s t-test. There were no significant differences (p &gt; 0.1) (NS) in patient age, weight, CD34+ cell count (data not shown) and PLT count prior to LP. There were also no differences in the proportion and the total CD34+ cells in the PBSC products collected by either machines. While both devices collected CD34+ cells with similar EFF (data not shown), the Amicus PBSC products have a trend (p = 0.08 and 0.07 when all LP or only those initiated with PLT count below 75,000/μl, respectively)towards a smaller volume (VOL) and contained significantly (p &lt; 0.05) fewer PLT than those collected by Spectra. The PLT EFF was also significantly lower with Amicus, indicating a smaller PLT loss. The same findings were observed whether all LP or only those LP initiated with low PLT counts (&lt; 75, 000/μl) were considered. Our results showed that lower PLT loss is achieved with Amicus during autologous PBSC collection. The machine would be more appropriate for collecting patients with low PLT counts.
Table 1: PLT Loss during Autologous PBSC Collection in Amicus or Spectra N Pre LP PLT (x103/μ l) LP VOL (ml) LP Total PLT (x1010) PLT EFF (%) ALL LP Spectra 17 49.5 ± 20.2 178.0 ± 41.7 8.7 ± 3.5 17.6 ± 16.9 Amicus 40 57.0 ± 32.9 164.5 ± 16.5 6.8 ± 2.6 8.4 ± 4.1 p value NS ≤ 0.08 ≤0.05 ≤0.05 Low PLT Spectra 17 49.5 ± 20.2 178.0 ± 41.7 8.7 ± 3.5 17.6 ± 16.9 Amicus 35 46.8 ± 15.4 162.9 ± 16.8 6.5 ± 2.4 9.0 ± 3.9 p value NS 0.07 ≤ 0.05 ≤ 0.05
Highly Efficient Peripheral Blood Progenitor Cell Mobilization in Myeloma Patients by Single-Dose Application of 12 mg Pegylated G-CSF.
Authors: Fruehauf Stefan , Seeger Timon , Topaly Julian , Ho Anthony D. , Goldschmidt Hartmut 
Published: April 2020

Abstract
Autologous peripheral blood stem cell (PBSC) transplantation leads to significant prolongation of survival in patients with different malignancies. For PBSC mobilization a combination of myelosuppressive chemotherapy and granulocyte colony stimulating factor (G-CSF) are administered. The optimal application of G-CSF is twice daily. New G-CSF formulations with prolonged half-life carry the promise of reduced patient strain, increased compliance and via continuously high G-CSF serum levels possibly improved PBSC mobilization. We initiated a study with pegfilgrastim-supported mobilization chemotherapy in stage II and III myeloma patients. Patients received up-front treatment with three cycles of vincristin, doxorubicin, dexamethason (VAD) or thalidomide, doxorubicin, dexamethason (TAD).
The mobilization regime consisted of four days chemotherapy with cyclophosphamide 1g/m2 day1, doxorubicin 15mg/m2 day 1–4, dexamethason 40 mg d 1–4 p.o. (CAD) and a single administration of 12 mg pegfilgrastim subcutaneously on day five. 25 patients (median age 57, 12 female, 13 male) received pegfilgrastim and leukapheresis was started 6–17 days (mean 10 days) after treatment with a range of maximum CD34 cell count between 7,2 and 842 (mean: 119) CD34+ cells/μl peripheral blood. After leukapheresis 6.2 * 10e6 to 40.5 * 10e6 (mean 13.8 *10e6) CD34+ cells per kilogram body weight were collected. 11 patients achieved the target number of 7.5 * 10e6 CD34+ cells per kilogram body weight during a single apheresis, while 5 patients needed two, 7 patients needed three and 2 patients needed four apheresies on consecutive days. 3 patients required additional administration of filgrastim. 2 patients received 6 mg pegfilgrastim off study. Both achieved sufficient numbers of CD34+ cells (12.7 and 20.8 * 10e6 CD34+ per kg BW). There were only minimal adverse effects. Four patients reported of bone pain or nausea. Mobilization failures did not occur in this patient population. To date, 16 patients have been transplanted with a mean of 6,03* 10e6 CD34+ per kg BW (range 2,4 to 13,5). Reconstitution (reaching a leukocyte count of &gt;1,0/nl) was reached within a mean of 13 days (range 11–21). On the basis of these first results we conclude that a single dose application of 12 mg pegfilgrastim after CAD treatment allows collection of more than 3 autografts in two or less apheresis session in the majority of myeloma patients. Reduction of apheresis sessions is a significant clinical cost-effectiveness end point in PBPC mobilization.