julilili42/papers huggingface dataset:
Radioimmunotherapy with Yttrium-90-Ibritumomab Tiuxetan as Part of a Reduced Intensity Conditioning Regimen for Allogeneic Hematopoietic Cell Transplantation in Patients with Advanced Non-Hodgkin Lymphoma: A Phase I/II Study.
2007-11-16

Abstract Allogeneic hematopoietic cell transplantation (HCT) using reduced intensity conditioning (RIC) regimens offers a potential curative therapy to patients with advanced NHL. RIC HCT induces potent graft-versus-lymphoma effects with best results in patients with low tumor burden at time of HCT. Combined use of radioimmunotherapy (RIT) with RIC may increase anti-lymphoma activity of RIC while HCT provides rescue from hematologic toxicity of RIT. This may allow dose escalation of RIT. A multicenter phase I/II study of allogeneic HCT combining RIT using yttrium-90-ibritumomab tiuxetan (Y90-CD20) with two RIC regimens for treatment of patients with NHL has been initiated. Patients with indolent NHL (Arm A) receive RIT with Y90-CD20 (0.4 mCi/kg) on day −14 combined with RIC using fludarabine (30 mg/m^2 day −4 to−2) and 2 Gy TBI (day 0). Patients with aggressive NHL (Arm B) receive an escalated dose of Y90-CD20 (0,6–0,8 mCi/kg) on day −14 combined with RIC using fludarabine (30 mg/m^2 day −8 to−4), melphalan (140 mg/m^2 day −3) and campath (20–30 mg day −3 to−2). For postgrafting immunosuppression either CSA/MMF (Arm A) or CSA alone (Arm B) is used. To date, 31 patients have been enrolled (Arm A=23, Arm B=8). Diagnoses in Arm A were FL (n=12), MCL (n=6), CLL (n=4) and Immunocytoma (n=1). Diagnoses in Arm B were DLBCL (n=6), blastoid MCL (n=1) and transformed CLL (n=1). Median age was 55 (range, 34–67) years. PBSC grafts were either from matched related (n=10) or matched unrelated donors (n=21). All patients were high risk with refractory disease or relapse after preceding HCT. Disease status after salvage therapy at time of HCT was in Arm A: CR=1, PR=18, SD=4 and in Arm B: PR=8. No additional toxicity due to RIT was observed. Engraftment was rapid and sustained with no graft rejections. In Arm A median time to &gt;500 granulocytes/μL was 13 (range, 0–69) days and to &gt;20000 platelets/μL 3 (range, 0–69) days (in 11 patients platelets never dropped &lt;20000/μL). In Arm B median time to &gt;500 granulocytes/μL was 17 (range, 9–23) days and to &gt;20000 platelets/μL 11 (range, 8–29) days. TRM in the first 100 days was 3%, overall 19%. Incidence of grade II-IV GVHD in Arm A was 35% (II=3, III=4, IV=1) and in Arm B 25% (II=2). Best disease response observed was in Arm A: CR=18, PR=5 and in Arm B: CR=3, PR=5. To date, 16/23 patients in Arm A and 6/8 patients in Arm B are alive with a median follow-up of 271 (range, 20–390) days, resulting in a Kaplan-Meier 1 year survival estimate of 65% in Arm A and 62% in Arm B. Causes of death were infection=5, GVHD=1, relapse=1 in Arm A and relapse=2 in Arm B. A combination of RIT with RIC is feasible with no additional toxicity due to RIT and stable engraftment in all patients. Preliminary response data suggest that this strategy may improve early post-transplant disease control, but long-term disease-free survival remains to be determined.
BMP and Wnt Induce Embryonic Blood Fate by Activation of the Cdx-Hox Pathway.
2007-11-16

Abstract The hematopoietic morphogen BMP4 has been implicated in early blood development, however the precise role and the underlying genetic pathways that link BMP action to blood fate specification remain poorly understood. In this study, we have employed the in vitro system of murine embryonic stem (mES) cell differentiating into embryoid bodies (EBs) as a model to explore mesoderm induction and hematopoietic specification during mammalian embryogenesis. We show that BMP plays a role in blood fate specification in two sequential phases: initially, BMP acts as a dorsoventral patterning agent, inducing ventroposterior mesoderm; at a later phase, BMP is required for hematopoietic fate specification from mesoderm. In dissecting this second specification phase, we discovered a previously unsuspected coordination between BMP4 and Wnt3a signaling, and linked these morphogens directly to Cdx and Hox genes. Using chromatin immunoprecipitation assays performed on EB-derived cells, we detected the association of the Wnt signaling effector LEF1 with the proximal Cdx1 promoter. This association was modulated by BMP signaling. In promoter reporter assays both BMP4 and Wnt3a activated the Cdx1 promoter while Wnt inhibitors or point mutations in the LEF1 responsive elements of the Cdx1 promoter abrogated this response. Together, these results suggest that BMP4 activates the Cdx1 promoter via LEF1 and the Wnt pathway. In functional assays, inhibition of Wnt signaling strongly suppressed the formation of hematopoietic colony initiating cells, suggesting that activation of the Wnt-Cdx-Hox pathway is a central downstream component of the BMP dependent blood fate specification program. Using ES cell lines engineered for conditonal Cdx1 or Cdx4 gene overexpression, we demonstrate that ectopic activation of Cdx genes is sufficient to establish hematopoietic fate decisions in the absence of BMP signaling during mesoderm specification to blood. Finally, to explore the relevance of our findings in vivo, we studied the effects of conditional BMP overexpression on cdx4 expression and embryonic blood formation during zebrafish embryogenesis. Matching our results with EBs, we find that overexpression of bmp2b at midgastrulation expands the cdx4 expression domain and strongly enhances blood formation. Taken together our results reveal an interaction between the BMP and Wnt signaling pathways, upstream of the Cdx genes, that is critical for the induction of the embryonic blood cell program. Given the evolutionary conservation of the BMP-Wnt-Cdx-Hox effect on blood formation from fish to mice, we anticipate that similar pathways can be exploited to direct the differentiation of human ES cells into blood.
Haploidentical Allogeneic Hematopoietic Cell Transplantation in Adults with CD3/CD19-Depleted Grafts after Reduced-Intensity Conditioning: A Phase I/II Study.
2007-11-16

Abstract Introduction: Haploidentical hematopoietic cell transplantation (HHCT) after high dose conditioning with a megadose of CD34-selected stem cells has been complicated by regimen related toxicities, slow engraftment and delayed immune reconstitution leading to a high treatment related mortality (TRM). A new regimen using graft CD3/CD19 depletion and reduced intensity conditioning (RIC) may allow HHCT with lower toxicity and faster engraftment. CD3/CD19 depleted grafts not only contain CD34+ stem cells but also CD34 negative progenitors, dendritic-, natural killer- and other graft-facilitating cells which may allow stable engraftment even without the use of a megadose of CD34+ cells. Methods: A multicenter phase I/II study of HHCT using RIC with fludarabine (150–200 mg/m2), thiotepa (10 mg/kg), melphalan (120 mg/m2), OKT-3 (5 mg/day, day −5 to +14) and graft CD3/CD19 depletion with anti-CD3 and anti-CD19 coated microbeads on a CliniMACS device has been initiated. No post grafting immunosuppression was applied if the graft contained &lt;5×104 CD3+ cells/kg. Results: To date, 36 patients (median age=46 [range, 21–65] years) have been enrolled in this study. Diagnosis were AML (n=20), ALL (n=7), NHL (n=3), MM (n=2), CML (n=2) and MCL (n=2). Patients were high risk with refractory disease or relapse after preceding HCT (auto=6, allo=12). The CD3/CD19 depleted haploidentical grafts contained a median of 7.5 × 106 (range, 3.4–17×106) CD34+cells/kg, 2.8×104(range, 0.4–44×104) CD3+T-cells/kg and 3.8×107 (range, 0.02–37.3 x107) CD56+cells/kg. Donor-recipient KIR-ligand-mismatch was found in 20 of 36 patients. The regimen was well tolerated with maximum acute toxicity being grade 2–3 mucositis. Five cases of reversible peripheral neuropathy and 3 cases of progressive multifocal leukencephalopathy (PML) occurred posttransplant in heavily pretreated patients. Engraftment was rapid with median time to &gt;500 granulocytes/μL of 12 (range, 9–21) days, &gt;20000 platelets/μL of 11 (range, 7–30) days and full donor chimerism after 2–4 weeks in all but one patient. Incidence of grade II-IV GVHD was 36% with grade II=9, III=2 and IV=2. TRM in the first 100 days was 10/36 (27%). Overall survival is 16/36 patients (44%) with deaths due to relapse (n=9), infection (n=9), GVHD (n=1) and PML (n=1) with a median follow-up of 194 days (range, 14–1271), resulting in a Kaplan-Meier 1 year survival estimate of 41%. We did not observe a statistical significant survival advantage for patient transplanted from a KIR-mismatched donor. Conclusion: This regimen is promising in high risk patients lacking a suitable donor, and a prospective phase I/II study is ongoing.
Role of CD137/4-1BB and Its Ligand in the NK Cell Mediated Immune Surveillance of Acute Myeloid Leukemia.
2007-11-16

Abstract NK cells play an important role in the reciprocal interaction of tumor cells with the immune system and participate in the surveillance and eradication of hematological malignancies including acute myeloid leukemia (AML). NK cell reactivity is governed by a balance of activating and inhibitory receptors including various members of the TNF receptor (TNFR) superfamily. The TNFR superfamily member CD137/4-1BB has been shown to stimulate proliferation and IFN-γ production, but not cytotoxicity of NK cells in mice. Surprisingly, yet nothing is known regarding the consequences of CD137-CD137 ligand (CD137L) interaction for NK cell reactivity in humans. In this study we demonstrate that CD56dimCD16+ but not CD56brightCD16− NK cells express CD137 upon stimulation with the activating cytokines IL-2 and IL-15 with peak expression between 48 and 60h. Furthermore, we found that 5 of 7 investigated AML cell lines and 16 of 51 (33%) primary AML cells of patients expressed substantial CD137L levels, while no CD137L expression was detected on CD34+ cells of healthy donors (n=5). CD137L expression was not restricted to a specific French-American-British (FAB) subtype, but was significantly (p&lt;0.05, one-way ANOVA) associated with monocytic (FAB M4, M5) differentiation. In addition, no association with a particular cytogenetic abnormality or with expression of MHC class I was observed. Reverse signaling via CD137L into AML cells (n=10) significantly induced the release of the immunoregulatory cytokines IL-10 and TNF (both p&lt;0.05, Mann-Whitney U-test). Surprisingly and in contrast to available data regarding the function of murine CD137, we found that in humans blocking CD137-CD137L interaction caused a significant increase in NK cell cytotoxicity and IFN-γ production about 50% (both p&lt;0.05, Mann-Whitney U-test) in coculture assays with CD137L-expressing patient AML cells and AML cell lines. The inhibitory effect of CD137 on NK cell reactivity was further confirmed in cocultures of NK cells with CD137L-transfectants and by triggering CD137 with an agonistic monoclonal antibody. This indicates that CD137 mediates opposite effects in murine compared to human NK cells. Furthermore we conclude that CD137L expression substantially influences tumor immunoediting by AML cells and diminishes NK cell reactivity against AML.
Defining the Leukemia Epigenome: Distinct Genome Wide Histone H3 Modification Patterns Exist in AML, ALL and Healthy Hematopoietic Progenitor Cells.
2007-11-16

Abstract Aberrant transcriptional regulation plays a crucial role in the pathogenesis of acute leukemias. Chromosomal translocations and other mutations frequently affect transcription and chromatin regulation-associated genes in these diseases. Based on these findings we hypothesized that distinct global chromatin modification patterns exist that can distinguish between progenitor cells (CD34+ HSC) and acute leukemia as well as its subtypes. We used high density oligonucleotide ChIP-Chip assays querying more than 31,000 genomic loci to analyze global Histone H3 acetylation (H3Ac) and Lysine 9 (H3K9me3) trimethylation patterns each in a large number of AML (n=115), ALL (n=30), CD34+ HSC (n= 21) and peripheral blood cell (N=18) specimens. Class comparisons and predictions as well as unsupervised analyses were performed. Bioinformatic analyses led to histone modification maps across the genome with Histone H3 acetylation levels peaking around the predicted transcriptional start sites. More than 1000 loci differed in H3 acetylation and H3K9me3 between AML and CD34+ specimens (5% FDR). Among the regulatory classes over-represented among the altered genes were those involved in oncogenesis and cellular proliferation/differentiation. Histone H3 acetylation and H3K9me3 patterns also differed at hundreds of loci between ALL and AML samples (5% FDR). Genes involved in transcriptional regulation were significantly altered between the two leukemia subtypes. Specific differences in global chromatin modifications allowed support vector machine-based classification of CD34+ progenitor cells, AML, and ALL, with about 90% sensitivity and specificity based on Histone H3 acetylation patterns. A similar classification power was observed for H3K9me3. Within the AML patients, several groups of patients were identified that clustered together in unsupervised hierarchical cluster analysis due to similar histone modification patterns. These patterns did not primarily depend on patients′ karyotypes,, indicating that it may be possible to define some, as yet unknown, different types of AML based on chromatin modification. On a global scale, acute leukemias are associated with specific histone modification patterns that distinguish AML from ALL and CD34+ hematopoietic progenitors. Taken together, these first data on the leukemia epigenome provide the basis for improved understanding of genes involved in leukemia pathogenesis.
Toll-Like Receptor-Induced Expression of the NKG2D Ligand MICA on Monocytes Modulates Their Interaction with NK Cells.
2007-11-16

Abstract Reciprocal interactions of NK cells with Dendritic Cells (DC) have been shown to influence activation of NK cells as well as maturation or lysis of DC and subsequent adaptive immune responses. However, little is known about the interaction of peripheral blood Monocytes with NK cells. Here we report that stimulation of Toll-like receptors (TLR) on Monocytes using LPS, Pam3Cys, R848 and PolyI:C induced mRNA and surface expression of MICA but no relevant changes of the further ligands of the activating immunoreceptor NKG2D, MICB or ULBP1-3. MICA upregulation upon stimulation with TLR ligands correlated with CD80 and HLA-DR upregulation and increased secretion of the pro-inflammatory cytokines IL-6, IL-8 and TNF by Monocytes. Interestingly, high MICA surface expression on activated Monocytes was not accompanied by a release of MICA in soluble form. The LPS-induced MICA upregulation by Monocytes was highly sensitive since it was observed with as little as 4 ng/ml LPS after 15 hours and was associated with IL-6 secretion and inhibition of apoptosis indicating that Monocytes were activated and functional. To determine whether upregulated MICA expression on Monocytes was detected by NK cells we took advantage of the fact that NKG2D is down-regulated after interacting with its ligands. While NKG2D levels on NK cells were not substantially changed in cultures with unstimulated Monocytes, a marked reduction of NKG2D was observed in the presence of activated MICA-expressing Monocytes. The modulation of NKG2D did not occur when NK cells and monocytes were separated by a transwell filter, which demonstrates that the numerous cytokines produced by TLR-activated Monocytes are not responsible for the NKG2D modulation and confirmes the role of MICA in Monocyte-NK cell interaction. Importantly, TLR-induced MICA expression on Monocytes stimulated IFN-γ production of NK cells, which could be reduced by addition of blocking anti-MICA/B F(ab’)2 fragments while isotype control had no effect. This demonstrates that the observed stimulation of NK cells was in fact specifically due to NKG2D-NKG2DL interaction. Our data indicate that NKG2D-MICA interaction provides a mechanism by which NK cells and Monocytes may communicate directly during innate immune responses to infections in humans.
hDectin-1 Mediates Cross-Presentation of Epitopes Via the Cytosolic Pathway.
2007-11-16

Abstract Human (h)Dectin-1 is a member of the C-type-lectin-like receptor family that was shown to be the major receptor for fungal β-glucans and to play an important role in cellular responses mediated by these carbohydrates. It is mainly expressed on human DCs and macrophages. In our study, we observed that activation of monocyte-derived dendritic cells (MDCs) with TLR3 ligand (poly I:C) but not with TLR ligand 7/8 (R848) resulted in down-regulation of hDectin-1 expression and this down-regulation correlated with a reduced uptake of apoptotic cells in phagocytosis assays. In order to analyze the possible cross-presentation of engulfed antigens we used CMV infected human fibroblasts (HFF). We found that hDectin-1 is involved in the uptake of CMV-infected HFF leading to cross-presentation of CMV-derived peptides on MHC class I molecules and activation of CMV pp65-specific CD8+ T-lymphocytes. To further delineate the pathway leading to presentation, we pretreated MDCs with compounds that inhibit processing of antigens at defined steps during presentation. Cytosolic protein degradation is performed by the proteasome, a large multicatalytic protease complex. Lactacystin specifically inhibits the 20S and 26S proteasome activity by targeting the catalytic subunit. In standard 51Cr-release assays, addition of lactacystin completely inhibited the presentation of pp65-derived peptides indicating the involvement of the proteasome in these process. The fungal product brefeldin A blocks the MHC class I processing pathway by specifically inhibiting the vesicular egress from the ER and the Golgi complex. In line with previous findings, incubation with brefeldin A almost completely abolished the lysis of MDCs incubated with CMV+ HFF. To further analyze whether the cross-presentation of CMV-derived peptides on HLA class I molecules was dependent on lysosomal proteases, MDCs that were co-incubated with HFF as above were treated with the lysosomotropic agent chloroquine that prevents acidification of the lysosomal compartment involved in the exogenous pathway of antigen presentation. The addition of chloroquine had no effect on the cross-presentation of CMV-derived epitopes on HLA class I-molecules. Summarized, the data reported here show that hDectin-1 functions not only as a pattern recognition receptor in innate immunity but is also involved in the clearing of apoptotic cells and cross-presentation of cellular antigens on MHC class I molecules to specific CTLs.
Treatment of Relapse of AML and MDS after Allogeneic Stem Cell Transplantation Using Low-Dose Chemotherapy, Donor PBSC and GM-CSF: Final Results from a Prospective, Multicenter Phase II Trial by the German Cooperative Transplant Group.
2007-11-16

Abstract No standard treatment is available for relapse of acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) after allogeneic stem cell transplantation (alloSCT). Efficacy of donor lymphocyte transfusion (DLT) was limited, at least in part, by the rapid pace of the disease, overwhelming any allogeneic immune response. However, induction chemotherapy before DLT was complicated by severe toxicity. Based on a pilot trial conducted in Munich, a prospective, multicenter phase II trial for relapsed AML and MDS after alloSCT was initiated in 2000 by the German transplant cooperative group. The study evaluated the sequence of low-dose(ld)AraC for leukemic control (intensive chemotherapy for progressive disease only), transfusion of donor PBSC without immunosuppression as adoptive immunotherapy, and systemic application of GM-CSF. GM-CSF was included, since in combination with other cytokines, it has been able to improve the antigene presentation capacity of myeloid blasts in vitro. Between 2000 and 2006, 41 patients with hematological relapse of AML or MDS &amp;gt;3 months after alloSCT were included. Median age was 47y, 50% had an unrelated donor. Median remission after SCT was 223d (93–1614), median percentage of BM blasts at relapse was 40%. Median follow up was 28 months. Control of leukemic proliferation by ldAraC was achieved in 61%, allowing outpatient care in the majority of these patients. 39% required intensive chemotherapy. Three patients died from infections before donor cell transfusion (DCT), one patient was not transfused due to progressive leukemia. Median time from relapse to DCT was 52 days. 25/34 evaluable patients were found to be free of blasts in BM at d35 after PBSC and were considered initial responders. In an intent-to-treat analysis, overall survival (OS) of the entire cohort at 1 and 2 years from relapse was 41% and 32%. Among initial responders, 1y- and 2y-OS was 68% and 49%. A remission &amp;gt;6months after alloSCT, and control of leukemia by ldAraC prior to DCT were associated with better outcome. At last follow up, 8 patiens were in continous CR, 2 were alive with second relapse, 18 had died from leukemia, and 13 had died in remission or aplasia. In conclusion, ldAraC seems to be effective for initial control of leukemic proliferation in relapsed AML and MDS after alloSCT. A longer duration of post-transplant remission and response to ldAraC may identify patients who will benefit from adoptive immunotherapy. On an intend-to-treat-basis, the overall results of our trial compare favorably to other published strategies; nevertheless, outcome is still unsatisfying and warrants further investigation.
Translocation t(4;14) Is Not an Adverse Prognostic Factor in Patients with Multiple Myeloma Undergoing Allogeneic Stem Cell Transplantation.
2007-11-16

Abstract We analyzed the prognostic impact of the most frequent genetic abnormalities detected by fluorescence-in situ-hybridization combined with immunofluorescent cytoplasm immunoglobulin staining (cIg-FISH) in 101 patients with multiple myeloma, who underwent allogeneic stem cell transplantation after reduced melphalan/fludarabine-based conditioning from related (n=34) and unrelated (n=67) donors. The abnormalities were del(13q14) [62%], t(11;14)(q13;q32) [11%], t(4;14)(p16.3;q32) [16%], CMYC-gains (8q24) [17%], del(17p13.1) [16%], t(14;16)(q32;q23) [4%], whereas none of the patients had t(6;14)(p25;q32). Translocation t(4;14), CMYC-gains and del 17p were frequently associated with del(13q14): 64%, 80% and 92%, respectively. The complete remission (CR) rate was 45% for all patients. Patients with del(17p13) achieved fewer complete remission than others (7% vs. 56%; p=0.001), while no difference was seen for t(4;14) and other abnormalities. Univariate analysis revealed higher relapse rates for age &gt; 50 years (p=0.002), del(13q14) (p=0.006) and del(17p13) (p=0.003). Patients with translocation t (4;14) had a similar four year event-free survival than others (50 vs 45%). In a multivariate analysis, only del(13q14) [HR: 2.34, p=0.03] and del(17p13) [HR: 2.24; p=0.04] influenced the risk of relapse, while for event-free survival, only age [HR 2.8; p=0.01] and del(17p13) [HR: 2.05; p=0.03] retained the prognostic value. These data seem to indicate that some adverse cytogenetic risk factors such as t(4;14) can be overcome by allogeneic stem cell transplantation, probably due to the graft versus myeloma effect. Del(17p13.1) is a significant factor for a lower chance of complete remissions and shorter event free survival following allogeneic stem cell transplantation. The presented data will have implications for risk-adapted strategies in the future.