bluuebunny/crossref_metadata_2025_split huggingface dataset:
Donor CD4+ T and B Cells in Transplants Induce Autoimmune-Like Chronic Graft Versus Host Disease.
Authors: Zhang Chunyan , Todorov Ivan , Zhang Zhifang , Liu Yinping , Kandeel Fouad , Forman Stephen , Strober Samuel , Zeng Defu 
Published: April 2020

Abstract
Chronic graft-vs-host disease (GVHD) is a major morbidity and mortality of long-term survivors of allogeneic hematopoietic cell transplantation (HCT). Chronic GVHD can have features of an autoimmune collagen-vascular disease with clinical manifestations similar to autoimmune scleroderma and systemic lupus erythematosus (SLE). However, the pathogenesis of chronic GVHD is poorly understood. It is unclear how autoreactive T and B cells are generated in chronic GVHD recipients. We have recently developed a new autoimmune-like chronic GVHD model by transplantation of donor DBA/2 (H-2d) spleen cells into MHC-matched but minor antigen-mismatched sublethally irradiated BALB/c (H-2d) recipients, as well as athymic BALB/c nu/nu and adult thymectomized BALB/c recipients. Both euthymic and athymic BALB/c recipients developed high-levels of serum IgG autoantibodies, sclerodermatous skin damage and glomerulonephritis. Disease induction required both donor CD25−CD4+ T and B cells in transplants. In contrast, donor CD25+CD4+ T regulatory (Treg) cells prevented the disease induction. These results indicate that host thymus is not required for induction of autoimmune-like chronic GVHD, and that quiescent autoreactive T and B cells in transplants from non-autoimmune donors may be activated and expanded to cause autoimmune-like chronic GVHD in allogeneic recipients, and donor Treg cells can suppress this process.
Pathological Anti-β2-Glycoprotein I Antibodies Disrupt the Anticoagulant Activity of Annexin A5: A Possible Explanation for the Lupus Anticoagulant Paradox.
Authors: de Laat Bas , Wu Xiao-Xuan , van Lummel Menno , Derksen Ronald H.W.M. , de Groot Philip G. , Rand Jacob H. 
Published: April 2020

Abstract
One of the most enigmatic features of the antiphospholipid (aPL) syndrome is the paradoxical correlation between thrombosis and the in vitro lupus anticoagulant (LAC) effect. It has recently been shown that only LAC that are due to β2-glycoprotein I (β2GPI) antibodies correlate with thrombosis. It has also been reported that aPL antibodies can disrupt the formation of an anticoagulant crystal shield that is formed by annexin A5 (AnxA5) over phospholipids bilayers. This disruption can be assayed by measuring resistance to AnxA5 anticoagulant activity. We therefore investigated whether the presence of these β2GPI-dependent LACs might correlate with the disruption of AnxA5 anticoagulant activity. We performed a double blind study with 30 patients divided into three groups; Group A: plasma of patients that show a β2GPI-dependent LAC; Group B: plasma of patients that show a β2GPI-independent LAC; Group C: plasma of SLE patients without a LAC. As previously demonstrated, we were able to discriminate between a β2GPI-dependent and a β2GPI-independent LAC by titrating cardiolipin into the plasma sample. A β2GPI-dependent LAC could be normalized by the addition of cardiolipin in contrast to a β2GPI-independent LAC which was prolonged by cardiolipin. To investigate the effects on AnxA5, we performed an APPT-based coagulation assay. In this assay we added AnxA5 to the plasma of patients and measured the prolongation in clotting time. We calculated the ratio of the clotting time divided by the clotting time with AnxA5 added to the plasma (=AnxA5 ratio). This assay represents the resistance against AnxA5 and gives an indication of its effect on the anticoagulant shield formed by AnxA5. Eleven patients displayed a β2GPI-dependent LAC (group A, all thrombosis), that gave an AnxA5 ratio of 151.3% (± SD 14.5). For 9 patients that displayed a β2GPI-independent LAC (group B, thrombosis n=3) we found a ratio of 225.4% (± SD 29.4). Ten patients did not have LAC (group C, thrombosis n=2) that gave a ratio of 219.2% (± SD 31.0). The annexin A5 ratio of group A was significantly lower than the ratio of group B (P=0.0002) and group C (P=0.0001). There was no difference in AnxA5 ratio between group B and group C (P=0.7802). β2GPI-dependent LAC correlate strongly with both thrombosis and AnxA5 resistance. The results therefore suggest that anti-β2GPI antibodies that cause LAC, in contrast to aPL antibodies with other specificities, are capable of disrupting the anticoagulant effect of AnxA5 on phospholipids. The disruption of the AnxA5 anticoagulant shield by LAC-causing anti-β2GPI antibodies may be a mechanism for thrombosis in APS and offers a potential explanation for the LAC paradox.
Figure Figure
Syndecan-1 Is Expressed on a Subset of Hematopoietic Stem Cells and Affects Their Function and Susceptibility to Malignant Transformation.
Authors: Ranheim Erik A. , McDermott Sean P. , Alexander Caroline M. 
Published: April 2020

Abstract
Syndecan-1 (CD138) is a heparan-sulfate proteoglycan (HSPG) known to be involved in cytokine signaling and cellular migration in the extracellular matrix. Knockout mice lacking CD138 expression exhibit a profound resistance to Wnt-1 induced mammary carcinoma that may be secondary to changes in mammary progenitor cell number or function. To determine whether this represented a more global phenomenon, we assessed the effects of CD138 expression on tumorigenesis induced by IP administration of the chemical carcinogen, DMBA, to post-natal mice. CD138−/− mice were highly resistant to DMBA-induced lung, liver, and ovarian carcinomas with an 80% reduction in tumor incidence compared to CD138+/+ mice. Absence of CD138 also protected from DMBA-induced hematopoietic tumors, with 4/58 (6.9%) KO versus 11/56 (19.6%) WT animals developing hematopoietic proliferations. Moreover, upon histologic and phenotypic analysis, the tumors arising in WT animals all proved to be CD4+CD8+ T-lymphoblastic lymphomas, which was seen in only a single KO animal. The other CD138−/− mice instead developed a myeloproliferative disorder with extensive splenic extramedullary hematopoiesis. We hypothesized that differences in tumor susceptibility between WT and KO mice may be secondary to abnormalities in tissue specific stem cell numbers and/or function. Therefore, we examined the expression and function of CD138 on mouse hematopoietic stem cells (HSC) and found that CD138 is expressed on approximately one third of mouse long-term HSC (LT-HSC), as defined by the Kit+Thy1.1loLin−Sca+ (KTLS) phenotype. Knockout mice lacking CD138 expression have mildly reduced numbers of HSC in the bone marrow with Lin−Sca+Kit+ cells making up 0.073±0.017% of marrow cells in CD138−/− mice versus 0.098±0.019% in WT mice (p = 0.038, n=6). While apparently adequate for hematopoiesis throughout the first 18 months of life, these HSC are functionally defective in competitive reconstitution assays in wild-type recipients compared to syngeneic, CD138+/+ LT-HSC. CD45.2+Kit+Flk2-Lin−Sca+ LT-HSC from CD138−/− or control CD138+/+ C57/Bl6 mice were flow sorted and 200 purified LT-HSC were injected into lethally irradiated CD45 congenic recipients along with 3 x 105 syngeneic whole bone marrow cells. Peripheral blood was monitored for reconstitution of T, B, and myeloid cells by analysis of CD45 allele expression; and as shown in the figure, LT-HSC from CD138−/− (KO) donor mice gave significantly less total leukocyte (p = 0.03 at 12 wks.) and myeloid (CD11b+ cells) reconstitution versus WT donor LT-HSC. These data suggest that CD138 plays a critical role in HSC function and provide a potential mechanism for the tumor resistant phenotype of CD138−/− mice. We are currently assessing function (in vivo and in vitro) of CD138 positive and negative WT KTLS-defined LT-HSC to determine whether CD138 may further subdivide this heterogeneous population.
Figure Figure
Induction of Adipocyte Differentiation and Reduction of Hematopoesis-Supporting Activity of Mouse Stromal Cells by Suppression of Transcription Factor GATA-2.
Authors: Okitsu Yoko , Harigae Hideo , Seki Masanori , Fujiwara Toru , Takahashi Shinichiro , Yokoyama Hisayuki , Kameoka Junichi , Minegishi Naoko , Sasaki Takeshi 
Published: April 2020

Abstract
(Introduction) Aplastic anemia (AA) is characterized by peripheral pancytopenia and fatty bone marrow. An immunological attack to hematopoietic stem cells has been thought to be responsible for the development of the disease. Previously, we reported the expression of transcription factor GATA-2 is significantly decreased in CD34 positive cells in AA. Together with the phenotypes of hematopoietic stem cells in GATA-2 hetero-knockout mice, GATA-2 down-regulation may play a role in the reduction of a stem cell pool observed in AA. On the other hand, GATA-2 has been shown to be essential for the maintenance of immaturity of preadipocytes. If a pathological immune response in AA decreases the level of GATA-2 expression in not only hematopoietic stem cells but also stromal preadipocytes, it may accelerate the maturation of preadipocytes, leading to the formation of fatty bone marrow. To explore this possibility, the phenotypic change of stromal preadipocytes by suppression of GATA-2 was examined in this study.
(Method) The GATA-2 expression level was suppressed by using siRNA for GATA-2 in mouse stromal preadipocyte cell lines, TBR9 and TBR343. After the treatment with siRNA, the adipocyte differentiation was induced by the incubation with insulin and dexamethasone for 7days. Then, the maturation level was examined by oil drops formation judged by oil red staining, and by the expression level of adipcin and PPAR-γ mRNA. Supporting activity of hematopoietic colony formation was also evaluated by using mouse fetal liver cells after siRNA treatment.
(Results) By using designed siRNA, the GATA-2 expression was suppressed to 30% of control, whereas the expression level of GATA-3, which is co-expressed in preadipocytes, was unchanged. When GATA-2 was suppressed by siRNA, the oil drop formation and adipocyte-specific gene expression was significantly accelerated in both of stromal cells. Furthermore, the number of fetal liver hematopoetic colonies was significantly decreased by suppression of GATA-2, suggesting that GATA-2 down-regulation in stromal preadipocytes results in not only the acceleration of the maturation but also the reduced supporting activity of hematopoietic colony formation
(Conclusion) These results suggest that suppression of GATA-2 in hematopoietic tissues induces the characteristic features of AA, i.e., decreased the number of hematopoietic stem cells and increased number of mature adipocytes.
Expansion of Normal and Leukemic Human Hematopoietic Stem/Progenitor Cells Requires Rac-Mediated Interaction with Stromal Cells.
Authors: Schuringa Jan Jacob , Rozenveld-Geugien Marjan , Baas Inge , van Gosliga Djoke , Vellenga Edo 
Published: April 2020

Abstract
We have studied Rac signal transduction in human cord-blood (CB) and acute myeloid leukemia (AML) CD34+ cells and determined that Rac proteins are critically involved in the interaction between human stem/progenitor cells and stroma. Constitutive activation of Rac signaling was achieved by retroviral introduction of Rac1-V12 into CB-derived CD34+ cells, while inhibition of Rac signaling was established by retroviral introduction of dominant negative Rac1-N17 or by utilizing the Rac inhibitor NSC23766. Inhibition of Rac signaling resulted in a proliferative disadvantage of CB-CD34+ cells when cultured on MS5 stromal cells. Cells were severely disturbed in their migration towards and direct association with MS5 stroma when Rac signaling was inhibited. The Long Term Culture-Initiating Cells (LTC-ICs) migrated underneath the stromal MS5 layer within 24 hrs after plating, and similar results were obtained for about 50% of the Colony Forming Cells (CFCs). However, transient inhibition of Rac signaling for 24–72 hrs resulted in a shift of LTC-ICs and CFCs to the suspension phase as determined by colony assays and CAFC week 5 enumeration. When Rac signaling signal transduction was inhibited during the 5 week coculture period a dramatic decrease in LTC-IC frequency from 0.6% to 0.15% was observed. Many of these phenotypes were reversed in the presence of activated Rac1-V12, including improved migration towards and association with MS5 cells and elevated LTC-IC frequencies. Importantly, in CAFC assays using AML cells (n=8) that were enriched for leukemic stem cells on the basis of a CD34+/CD38low phenotype we observed a dramatic decrease in leukemic CAFC formation as well as strongly diminished clonal expansion in the presence of the Rac inhibitor NSC23766. Taken together, our data indicate that Rac signal transduction is required for the maintenance and expansion of both normal as well as leukemic stem/progenitor cells by mediating their interaction with stromal cells.
T-Cell Depleted PBSCT Mitigates Acute GVHD, but Preserves Protective Chronic GVHD. Long Term Follow up of 138 Patients.
Authors: Montero Aldemar , Savani Bipin N. , Mielke Stephan , Solomon Scott R. , Childs Richard , Barrett A. John 
Published: April 2020

Abstract
Between 1997 and 2004, 138 patients with hematological malignancies had an HLA-identical sibling peripheral blood stem cell transplant (PBSCT). Preparative regimen was TBI (12–13.6Gy), cyclophosphamide 120mg/kg +/− fludarabine 125mg/m2. T-cell dose was adjusted to 0.2-1 x 105 CD3+ cells/kg. CD34 dose was 2.7 – 15.9 x 106/kg (median 5.9). Patients without ≥ grade 2 acute GVHD received 1 or 2 donor lymphocyte infusions (DLI) of 107 CD3+ cells/kg between days 45 and 100. For GVHD prophylaxis, all patients received cyclosporine (CSA) following the DLI for a minimum of 6 months. In addition 72 patients received CSA in the first 6 weeks post PBSCT and 66 received no CSA immediately post-transplant. Patients were aged between 10–56 (median 34 years). Seventy-seven patients with CML-CP (42), acute leukemia in first remission (22) or MDS RA (10) were designated as standard risk (SR) for transplant outcome. Sixty-one patients with more advance or refractory disease were designated as high risk (HR) for transplant outcome. Seven patients, distributed in both groups had CLL, NHL, MM and CMML. Overall survival, relapse and TRM were 58 ± 4.5%, 40.2 ± 5.5% and 18.4 ± 3.4% respectively after a median follow up of 4 years. Twenty-two patients did not receive DLI, 70 received one and 46 received two DLI. Twenty-three patients had TRM, 2 from graft failure, 5 from acute or chronic GVHD. Fifty two (37%) developed ≥ grade II, and 21 (15%) patients grade III-IV acute GVHD. Forty two (30%) had limited and 30 (22%) extensive chronic GVHD. In univariate Kaplan-Meier analyses standard risk disease, cGVHD, single DLI and day 30 lymphocyte count (LC30) above median, favorably affected overall survival (DLI p=0.002; LC30 p=0.0002, all other variables p&lt;0.0001). Risk status was the strongest factor predicting relapse (28.8 ± 8% and 58.4 ± 7% in SR and HR patients respectively p&lt;0.0001). Fludarabine, degree of T-cell depletion, age, cyclosporine schedule and CD34 dose were not significant.
In a Cox regression analysis, only cGVHD (RR, 4.268; p=0.001; 95% CI=1.77–10.25) and standard risk (RR, 0.146; p&lt;0.001; 95%CI=0.06–0.35) remained as independent predictive factors for outcome (Figure A). On landmark analysis after day +120, cGVHD was associated with better OS (p&lt;0.0001) and DFS (p=0.0006) (Figure B), and relapse (21.7± 6% and 51.5 ± 11% in patients with and without cGVHD p= 0.002).
Aggressive T-cell depletion, combined with relatively high doses of CD34+ cells had proven to be a key strategy to minimize TRM and severe aGVHD. Similar to unmanipulated PBSCT this approach appears to provide a protective effect of chronic GVHD, but with low late mortality.
Figure Figure
Polymorphisms of NOD2/CARD15 Are Associated with Clinical Outcome in T-Cell Depleted HLA-Identical Sibling Allogeneic Stem Cell Transplantation.
Authors: Granell Miquel , Urbano-Ispizua Alvaro , Arostegui Juan Ignacio , Fernandez-Aviles Francesc , Martinez Carmen , Rovira Montserrat , Gaya Anna , Navarro Alfons , Talarn Carme , Carreras Enric , Monzo Mariano , Yague Jordi , Montserrat Emili 
Published: April 2020

Abstract
Three single nucleotide polymorphisms (SNP) in NOD2/CARD15 have been associated with the incidence and severity of acute GVHD following allogeneic stem cell transplantation (allo-SCT). The potential clinical influence of SNP in NOD2/CARD15 in a model of allo-SCT with a low incidence of GVHD, such as T-cell depleted transplants (TCD), has not been studied. We analyzed the association of SNP in NOD2/CARD15 with the outcome of 84 patients undergoing allo-SCT with TCD by means of CD34+ selection. Results were compared with a concurrent group of 94 patients receiving an allo-SCT with unmanipulated grafts (Non-TCD). Transplants were performed in a single institution, donors were HLA identical siblings and all patients received myeloablative-conditioning regimen. Median follow-up was of 30.6 months (range, 0.2–112). SNP 8, 12 and 13 were analyzed by RT-PCR allelic discrimination method in all patients and in 137 donors. SNP in NOD2/CARD15 were detected in 13.8% of patients and in 10.7% of donors. Results of the association of patient’s NOD2/CARD15 genotype and outcome are given in the table. In TCD transplants, independent risk factors associated with event free survival in a multivariate analysis were: patient’s NOD2/CARD15 genotype (RR 2.7, p=0.02), patient’s age (RR 2.3, p=0.03) and conditioning with radiotherapy (RR 2.7, p=0.03). The only association of donor’s NOD2/CARD15 genotype with clinical outcome in the multivariate analysis was with acute GVHD (RR 3.3, p=0.03). In conclusion, polymorphisms in NOD2/CARD15 have a strong association with clinical outcome in TCD transplants, which is independent of GVHD.
Overall group (n=178) SNP vs. WT P* TCD (n=84) SNP vs. WT P* Non-TCD (n=94) SNP vs. WT P* WT, wild type; N.S, non significant; * Log-rank test Acute GVHD II–IV 27 vs. 22 N.S 22 vs. 40 N.S 33 vs. 12 N.S Chronic GVHD 61 vs. 35 0.1 29 vs. 14 N.S 100 vs. 44 0.005 Event free survival 21 vs. 47 0.03 17 vs. 48 0.04 22 vs. 31 N.S Overall survival 30 vs. 59 0.01 33 vs. 56 0.04 30 vs. 48 N.S
IL-15 Plays a Critical Role in CD8+ T-Cell Recovery after Allogeneic Transplantation.
Authors: Hakim Frances T. , Allen Kenton , Carson Jesse M. , Boyiadzis Michael , Memon Sarfraz A. , Dean Robert , Odom Jeanne , Wayne Alan , Fowler Daniel , Bishop Michael R. , Gress Ronald E. 
Published: April 2020

Abstract
In severely lymphopenic hosts, CD4+ and CD8+ T cell populations increase rapidly through peripheral homeostatic expansion, a process in which IL-7 has been found to play a key role. Because of the marked differences in the kinetics of CD4+ and CD8+ T cell repopulation following hematopoietic stem cell transplants (HSCT), we have investigated the roles of additional cytokines in early repopulation. Interleukin-15 (IL-15) supports the proliferation, terminal differentiation, and survival of NK, NKT and memory CD8+ T-cell populations, all of which increase disproportionately in the early transplant period. We therefore investigated the role of IL-15 in post-transplant CD8+ T cell recovery by assessing plasma IL-15 levels, IL-15 receptor expression and IL-15-induced proliferation by BrdU incorporation. In patients undergoing non-myeloablative HLA-matched allogeneic HSCT for hematological and non-hematological malignancies, IL-15 levels in the plasma increased concurrent with the loss of lymphocytes during each cycle of inductive chemotherapy, and peaked at a 50-fold increase over pretreatment levels at day of transplant, a time when CD8+ T cell levels were usually less than 1 cell/μL. Plasma IL-15 levels fell rapidly in the first two weeks, during the rapid recovery of NK and CD8+ T cell populations, returning to pretransplant levels by 1–2 months. Overall, during the cytoreductive transplant and for the first year post transplant, the IL-15 levels were inversely proportional to the level of CD8 T cells (P &lt; 0.0001; r = −0.73). In the first weeks after transplant, CD8+T-cells expressed elevated levels of CD122, but had little or no expression of CD25, the IL-2Ralpha chain. Levels of CD122 remained elevated for several months, while expression of CD127, IL-7Ralpha, was reduced. In vitro BrdU incorporation assays demonstrated that CD8+ T-cells from both normal donors and transplant recipients responded primarily to IL-15, not IL-7 or IL-2. CD4+ T cells, in contrast, responded primarily to IL-7. A higher proportion of CD28+CD45RA− memory and CD28−CD45RA+/− effector-memory CD8+ T-cells incorporated BrdU than did naive CD28+CD45RA+ CD8+ T cells. Finally, IL-15, not IL-2 or IL-7, was found to maintain survival and support expansion in culture of the CD28−CD57+ terminal effector cells that dominate post transplant CD8+ T-cells populations. These data, describing an inverse relationship between the levels of free plasma IL-15 and CD8+ T cells, elevated expression of IL-15 receptor chain and strong responsiveness of post transplant CD8+ T cells to IL-15, suggest that IL-15 serves as a critical homeostatic cytokine post transplant, supporting the initial rapid generation CD8+ T cells and maintaining elevated levels of memory/effector CD8+ T-cell populations in the post transplant period.
Inverse Correlation of Early Regulatory T Cell Reconstitution Post-Transplant and Acute and Chronic Graft-Versus-Host-Disease.
Authors: Rezvani Katayoun , Mielke Stephan , Kilical Yasemin , Savani Bipin , Keyvanfar Keyvan , Hensel Nancy , Kurlander Roger , Barrett A. John 
Published: April 2020

Abstract
Data on the impact of regulatory T cells (Tregs) on GVHD following SCT in man is conflicting, possibly due to differences in techniques used to characterize them. We studied reconstitution of CD4+CD25+Foxp3+ T cells in the first 150 days following a T-depleted allogeneic SCT by surface phenotyping, Foxp3 gene expression and functional assays to characterize their post-transplant origin and pattern of recovery relating these findings to GVHD. Although there was a direct correlation between Foxp3 gene expression and CD4+CD25+ T cells in healthy donors the ratio between CD4+CD25+ T cell numbers and Foxp3 gene expression was more variable after SCT. In a longitudinal post-transplant study in 12 patients with leukemia, the Foxp3 copy number and CD4+CD25+ T cells were strongly correlated in 5. In 4 patients CD4+CD25+ and CD4+CD25+CD69+ T cells were disproportionately increased compared with Foxp3 gene expression, corresponding temporally with the development of acute GVHD and suggesting expansion of effector T cells. In 3 patients who did not develop clinically significant GVHD, the ratio of Foxp3 gene expression to CD25 fraction of CD4+ T cells was disproportionately high suggesting that Treg may have expanded or upregulated Foxp3 gene copy numbers. Treg reconstitution was slow in the first 45 days after SCT, lagging behind CD3 recovery but reaching normal levels by day 120. High day 30 Foxp3 gene expression inversely correlated with grade II–IV aGVHD (p = 0.02) and with severity of cGVHD. Chimerism analysis was performed on sorted CD4+CD25+ and CD4+CD25− T cell fractions from 7 patients on day120 samples. In most patients, the expanded Treg population was enriched in cells of donor origin. These results support strategies to prevent GVHD by increasing post-transplant Treg recovery by adoptive transfer of ex-vivo expanded Treg. Conversely, the absence of Treg together with lymphopenia-driven T cell expansion may offer a window of opportunity for boosting GVL effects by vaccination in the first few weeks after transplantation.
Figure Figure