Intensive oral care can reduce bloodstream infection with coagulase-negative staphylococci after neutrophil engraftment in allogeneic hematopoietic stem-cell transplantation.

PURPOSE: Bloodstream infection (BSI) is a major complication of allogeneic hematopoietic stem-cell transplantation (allo-SCT). There are several causes of BSI; in particular, severe oral mucositis (OM) can induce BSI due to coagulase-negative staphylococci (CoNS). The OM severity may be reduced with intensive oral care. Thus, we evaluated whether the type of oral care affects the BSI incidence eventually. METHOD: We performed retrospective analysis on 206 recipients who underwent allo-SCT from 2006 to 2017 at our institute. Intensive oral care by a dental specialist was performed for 111 recipients (intensive-care group) and self-oral care was performed by 95 recipients (self-care group). Incidence of BSI was assessed by type of the oral care, before neutrophil engraftment (pre-E-BSI) and after neutrophil engraftment (post-E-BSI) period until 180 days after allo-SCT. RESULT: A total of 112 BSI occurred in 90 of the 206 recipients and 120 bacteria were identified, with CoNS being the most prevalent. There was no significant difference in the incidence of pre-E-BSI between the self-care and intensive-care groups (30.8% and 30.6%, respectively; P = 0.508). Meanwhile, the incidence of post-E-BSI was significantly lower in the intensive-care group than in the self-care group (14.3% and 28.6%; P = 0.008). In addition, the intensive-care group had significantly lower incidence of post-E-BSI with CoNS than the self-care group (8.5% and 21.5%, respectively; P = 0.009). CONCLUSION: Intensive oral care through the period of allo-HCT can significantly reduce the post-E-BSI occurrence, especially due to CoNS.

Marker chromosome is a strong poor prognosis factor after allogeneic HSCT for adverse-risk AML patients.

INTRODUCTION: Chromosome analysis is necessary for the risk classification of acute myeloid leukemia (AML). Marker chromosome (MC) is a fragmented chromosome whose origin cannot be identified from other chromosomes and originates from marked genomic instability. Although AML with MC (MC+) has a poor prognosis even after intensive chemotherapy, its influence on the outcome after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is unclear. OBJECTIVE AND METHODS: We retrospectively analyzed 162 AML patients after allo-HSCT. To evaluate the significance of MC, we compared it with other chromosomal abnormalities. RESULT: Marker chromosome was detected in 14 (8.6%, MC+) patients (vs MC-, n = 158). The 2-year overall survival (OS) in MC+ vs MC- was 26.8% vs 62.2% (P = .0098). The 2-year cumulative incidence of relapse (CIR) in MC+ vs MC- was 80.4% vs 35.5% (P = .0004). Among adverse-risk AML (AD-AML, n = 36), AD-AML/MC+ (n = 11) demonstrated a poorer 2-year OS (9.1%, vs AD-AML/MC- n = 25, 58.3%, P = .0031) and higher 2-year CIR (89.6%, vs AD-AML/MC- 44.7%, P = .002). In multivariate analysis, MC (HR 3.08, 95% CI; 1.02-9.29, P = .046) and HCT-CI (HR 3.23, 95% CI; 1.00-10.4, P = .049) were independent risk factors for CIR among AD-AML. CONCLUSION: Our study suggests MC as a new independent factor for chromosome risk classification to further classify AD-AML.

Differential and Overlapping Immune Programs Regulated by IRF3 and IRF5 in Plasmacytoid Dendritic Cells.

We examined the signaling pathways and cell type-specific responses of IFN regulatory factor (IRF) 5, an immune-regulatory transcription factor. We show that the protein kinases IKKα, IKKß, IKKε, and TANK-binding kinase 1 each confer IRF5 phosphorylation/dimerization, thus extending the family of IRF5 activator kinases. Among primary human immune cell subsets, we found that IRF5 is most abundant in plasmacytoid dendritic cells (pDCs). Flow cytometric cell imaging revealed that IRF5 is specifically activated by endosomal TLR signaling. Comparative analyses revealed that IRF3 is activated in pDCs uniquely through RIG-I-like receptor (RLR) signaling. Transcriptomic analyses of pDCs show that the partitioning of TLR7/IRF5 and RLR/IRF3 pathways confers differential gene expression and immune cytokine production in pDCs, linking IRF5 with immune regulatory and proinflammatory gene expression. Thus, TLR7/IRF5 and RLR-IRF3 partitioning serves to polarize pDC response outcome. Strategies to differentially engage IRF signaling pathways should be considered in the design of immunotherapeutic approaches to modulate or polarize the immune response for specific outcome.

Absence of Mal/TIRAP Results in Abrogated Imidazoquinolinones-Dependent Activation of IRF7 and Suppressed IFNß and IFN-I Activated Gene Production.

Activation of TLR7 by small imidazoquinoline molecules such as R848 or R837 initiates signaling cascades leading to the activation of transcription factors, such as AP-1, NF-κB, and interferon regulatory factors (IRFs) and afterward to the induction of cytokines and anti-viral Type I IFNs. In general, TLRs mediate these effects by utilizing different intracellular signaling molecules, one of them is Mal. Mal is a protein closely related to the antibacterial response, and its role in the TLR7 pathways remains poorly understood. In this study, we show that Mal determines the expression and secretion of IFNß following activation of TLR7, a receptor that recognizes ssRNA and imidazoquinolines. Moreover, we observed that R848 induces Mal-dependent IFNß production via ERK1/2 activation as well as the transcription factor IRF7 activation. Although activation of TLR7 leads to NF-κB-dependent expression of IRF7, this process is independent of Mal. We also demonstrate that secretion of IFNß regulated by TLR7 and Mal in macrophages and dendritic cells leads to the IP-10 chemokine expression. In conclusion, our data demonstrate that Mal is a critical regulator of the imidazoquinolinones-dependent IFNß production via ERK1/2/IRF7 signaling cascade which brings us closer to understanding the molecular mechanism's regulation of innate immune response.

The Glasgow Prognostic Score as a pre-transplant risk assessment for allogeneic hematopoietic cell transplantation.

Evaluation methods, such as scoring systems for predicting complications in advance, are necessary for determining the adaptation of allogeneic hematopoietic cell transplantation (HCT) and selecting appropriate conditioning regimens. The Hematopoietic Cell Transplantation-specific Comorbidity Index (HCT-CI), which is based on functions of main organs, is a useful tool for pre-transplant risk assessments and has been widely applied in determining treatment strategies for patients with hematological diseases. However, as allogeneic HCT is performed on patients with diverse backgrounds, another factor, which reinforces the HCT-CI, is required to evaluate pre-transplant risk assessments. The Glasgow Prognostic Score (GPS), which assesses the combined C-reactive protein and albumin, was reported to predict survival of patients with solid-organ malignancies independently of receiving chemo/radiotherapy and stages of cancer. In this study, we applied the GPS for pre-transplant risk assessments for allogeneic HCT. The GPS successfully stratified the patients into three risk groups of overall survival (OS) and non-relapse mortality (NRM). Moreover, the GPS could predict outcomes independently of the HCT-CI for OS and NRM in multivariate analysis. The GPS is considered to be a useful tool and reinforces the HCT-CI for determining adaptation of allogeneic HCT for patients with hematopoietic neoplasms.

Rapid Complexation of Aptamers by Their Specific Antidotes.

Nucleic acid ligands, aptamers, harbor the unique characteristics of small molecules and antibodies. The specificity and high affinity of aptamers enable their binding to different targets, such as small molecules, proteins, or cells. Chemical modifications of aptamers allow increased bioavailability. A further great benefit of aptamers is the antidote (AD)-mediated controllability of their effect. In this study, the AD-mediated complexation and neutralization of the thrombin binding aptamer NU172 and Toll-like receptor 9 (TLR9) binding R10-60 aptamer were determined. Thereby, the required time for the generation of aptamer/AD-complexes was analyzed at 37 °C in human serum using gel electrophoresis. Afterwards, the blocking of aptamers' effects was analyzed by determining the activated clotting time (ACT) in the case of the NU172 aptamer, or the expression of immune activation related genes IFN-1ß, IL-6, CXCL-10, and IL-1ß in the case of the R10-60 aptamer. Gel electrophoresis analyses demonstrated the rapid complexation of the NU172 and R10-60 aptamers by complementary AD binding after just 2 min of incubation in human serum. A rapid neutralization of anticoagulant activity of NU172 was also demonstrated in fresh human whole blood 5 min after addition of AD. Furthermore, the TLR9-mediated activation of PMDC05 cells was interrupted after the addition of the R10-60 AD. Using these two different aptamers, the rapid antagonizability of the aptamers was demonstrated in different environments; whole blood containing numerous proteins, cells, and different small molecules, serum, or cell culture media. Thus, nucleic acid ADs are promising molecules, which offer several possibilities for different in vivo applications, such as antagonizing aptamer-based drugs, immobilization, or delivery of oligonucleotides to defined locations.

Successful umbilical cord blood hematopoietic stem cell transplantation in a patient with adult T-cell leukemia/lymphoma initially achieving complete remission with anti-CC chemokine receptor 4 antibody combined chemotherapy.

A 62-year-old man with CHOP refractory adult T-cell leukemia/lymphoma (ATLL) received anti-CC chemokine receptor 4 antibody (mogamulizumab) combined with CHOP and achieved complete remission. At 71 days after the final administration of mogamulizumab, he received umbilical cord blood transplantation (CBT) using reduced intensity conditioning. Umbilical cord blood engraftment was confirmed on day16. Grade II acute graft-versus-host disease (GVHD) was diagnosed on day60 and was controlled by administration of methylprednisolone. There was no evidence of relapse at 9 months after CBT. Ratios of regulatory T cells in CD4 positive T cells were remarkably low during all of these periods. Since mogamulizumab reduces regulatory T cells, the frequency and severity of acute GVHD were reported to be increased in patients administered mogamulizumab before allogenic stem cell transplantation. Further experiences are needed for selecting optimal donor sources, the portability period and GVHD prophylaxis for patients using mogamulizumab before allogeneic stem cell transplantation.

Peripheral T-cell lymphoma, not otherwise specified: a retrospective single-center analysis.

We retrospectively analyzed clinical and pathological features, treatments, and prognoses in 28 patients with newly diagnosed peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) in Niigata University Medical and Dental Hospital. Of them, 16 were males and 12 were females, and their median age was 62.5 (range, 26-88) years. The International Prognostic Index was high-intermediate/high in 68% of patients. Twelve patients were treated with CHOP/THP-COP and nine with third-generation chemotherapy regimens. At a median follow-up period of 30 (range: 1-164) months, the 2-year overall survival and progression-free survival rates were 61% and 44%, respectively. Further investigation of novel agents for treating PTCL-NOS is warranted.

Ustekinumab improves psoriasis without suppressing tumor antigen-specific cytotoxic T lymphocytes.

BACKGROUND: Ustekinumab is currently used for the treatment of psoriasis with remarkable efficiency. However, worries about the development of malignancies in ustekinumab-treated patients have not been completely resolved because of the major role of IL-12 and IL-23 in tumor immunity. In the present study, we tried to elucidate the effects of ustekinumab on antigen-specific tumor immunity. METHODS: After approval by the institutional ethical committee, a 56-year-old male volunteer with psoriasis was administered with 20 doses of WT1 peptide. WT1-specific cytotoxic T lymphocytes (CTLs) were evaluated by WT1 tetramer assay after mixed lymphocyte peptide culture. RESULTS: WT1 tetramer+ T cells with cytotoxic ability appeared in the blood after peptide administration and the frequency of WT1 tetramer+ T cells increased to more than 15 in 10(6) CD8+ T cells. Thirty months after stopping WT1 administration, the patient commenced treatment with ustekinumab for psoriasis at weeks 0 and 4, and every 12 weeks thereafter. Psoriasis plaques were almost cleared up and the response to ustekinumab has so far lasted for 30 months. The frequency of WT1 tetramer+ T cells has not changed since the initiation of ustekinumab treatment. The effects of ustekinumab on the antigen-presenting and CTL-inducing abilities of dendritic cells were explored in vitro, revealing limited effects on both immune functions. CONCLUSIONS: These in vivo/vitro findings imply that ustekinumab improves psoriasis without suppressing tumor antigen-specific CTLs and support the data of recent clinical trials showing no increased incidence of malignancies with ustekinumab treatment.

Decade-long WT1-specific CTLs induced by WT1 peptide vaccination.

INTRODUCTION: The peptide-based cancer vaccine targeting Wilms' tumor 1 (WT1) is a promising immunotherapeutic strategy for hematological malignancies. It remains unclear how long and to what extent the WT1-specific CD8 + cytotoxic T cell (CTL) persist after WT1 peptide vaccination. METHODS: The WT1 peptide vaccine was administered with written consent to a patient with CML in the chronic phase who did not respond well to imatinib, and the patient was followed for 12 years after vaccination. Immune monitoring was performed by specific amplification of WT1-specific CTLs using a mixed lymphocyte peptide culture. T-cell receptors (TCRs) of amplified WT1-specific CTLs were analyzed using next-generation sequencing. This study was approved by the Institutional Review Board of our institution. RESULT: WT1-specific CTLs, which were initially detected during WT1 peptide vaccination, persisted at a frequency of less than 5 cells per 1,000,000 CD8 + T cells for more than 10 years. TCR repertoire analysis confirmed the diversity of WT1-specific CTLs 11 years after vaccination. CTLs exhibited WT1 peptide-specific cytotoxicity in vitro. CONCLUSION: The WT1 peptide vaccine induced an immune response that persists for more than 10 years, even after cessation of vaccination in the CML patient.

Direct effect of dasatinib on proliferation and cytotoxicity of natural killer cells in in vitro study.

Lymphocytosis predominantly due to natural killer (NK) cells has been reported in nearly a half of chronic myelogenous leukemia (CML) patients who were being treated with dasatinib. Besides, dasatinib-treated patients with lymphocytosis have a better prognosis than patients without lymphocytosis. In order to elucidate the effects of dasatinib on the proliferation of lymphocyte subset, dasatinib was added to the culture of peripheral blood mononuclear cells with IL-2 (lymphokine-activated killer culture) or a low dose of IL-2 with zoledronate (γδ T-cell culture). In both culture conditions, NK cells were increased in both percentage and absolute number in the culture with dasatinib compared with control culture without dasatinib. The increase of NK cells was dose dependent of dasatinib in the range of 2-25 nM. NK cell cytotoxicity of cultured cells with dasatinib was demonstrated to be superior to control cells without dasatinib in cytotoxicity assay using EGFP-transfected K562 cells as target cells. The present study suggested that lymphocytosis in dasatinib-treated CML patients is at least partly associated with a direct effect of dasatinib to stimulate the proliferation of NK cells. Favourable prognosis in patients with dasatinib-induced lymphocytosis might be associated with the effects of dasatinib to potentiate NK cytotoxicity in vivo.

5'-Phosphate oligodeoxynucleotides enhance the phosphodiester-CpG DNA-induced inflammatory response in macrophages.

Dying cells release genomic DNA into the surroundings where the DNA is first degraded to oligodeoxynucleotides, then to nucleotides, nucleosides and so on. Given that the unmethylated CpG dinucleotide (CpG motif), which is characteristic of bacterial DNA, is also contained in mammalian DNA and has been reported to be involved in the exacerbation of DNA-associated autoimmune diseases, we investigated whether nucleotides and nucleosides affect immune responses to phosphodiester (PO)-CpG DNA. Addition of non-CpG DNA to RAW264.7, murine macrophage-like cells, induced no significant TNF-α production irrespective of treatment with DNase I; however, DNase I-treated, but not untreated, non-CpG DNA increased the PO-CpG DNA-mediated TNF-α production. This increase was not observed with phosphorothioate-CpG DNA or ligands for TLR3, TLR4 or TLR7. Deoxynucleotides with a 5'-phosphate showed similar effects to those of DNase I-treated non-CpG DNA, but DNase II-treated DNA or deoxynucleosides did not. Subcutaneous injection of PO-CpG DNA into the mouse footpad induced little swelling of the paw; however, significant swelling was observed when DNase I-treated DNA was co-injected with PO-CpG DNA. These results imply that PO-CpG DNA-dependent inflammatory responses are increased by DNA molecules with a 5'-phosphate; such molecules could therefore be considered as exacerbating factors for CpG motif-related inflammation.

Quantification of BCR-ABL mRNA in plasma/serum of patients with chronic myelogenous leukemia.

Quantification of tumor-associated mRNA extracted from blood cells/tissues containing tumor cells is used for evaluation of treatment efficacy or residual tumor cell burden in tumors including leukemia. However, this method using tumor cell-containing blood/tissue is difficult to evaluate the whole tumor cell burden in the body. In order to establish an efficient method to evaluate the whole tumor cell burden in the body, we tried to quantify tumor-associated mRNA existing in plasma/serum instead of leukemia cell-containing blood cells in patients with chronic myelogenous leukemia (CML) and compared the levels of BCR-ABL mRNA between plasma/serum and peripheral blood cells. mRNA of BCR-ABL, WT1 or GAPDH (control molecule) was detected by real-time RT-PCR using RNA extracted from plasma/serum of almost all the patients with CML. Copy numbers of BCR-ABL mRNA were significantly correlated between plasma/serum and peripheral blood cells. However, levels of BCR-ABL mRNA extracted from serum were low compared with those extracted with peripheral blood cells. The present findings suggest that although real-time RT-PCR of mRNA existing in plasma/serum could be used for evaluating the whole tumor cell burden in the body, it's required to establish an efficient method to quantify plasma/serum mRNA by nature without degrading during the procedure.

The Immunomodulatory Effect of Triptolide on Mesenchymal Stromal Cells.

Mesenchymal stromal cells (MSCs) are known to have immunosuppressive ability and have been used in clinical treatment of acute graft-versus-host disease, one of severe complications of the hematopoietic stem cell transplantation. However, MSCs are activated to suppress the immune system only after encountering an inflammatory stimulation. Thus, it will be ideal if MSCs are primed to be activated and ready to suppress the immune reaction before being administered. Triptolide (TPL) is a diterpene triepoxide purified from a Chinese herb-Tripterygium wilfordii Hook.f. It has been shown to possess anti-inflammatory and immunosuppressive properties in vitro. In this study, we aimed to use TPL to prime umbilical cord-derived MSCs (TPL-primed UC-MSCs) to enter a stronger immunosuppressive status. UC-MSCs were primed with TPL, which was washed out thoroughly, and the TPL-primed UC-MSCs were resuspended in fresh medium. Although TPL inhibited the proliferation of UC-MSCs, 0.01 µM TPL for 24 h was tolerable. The surface markers of TPL-primed UC-MSCs were identical to those of non-primed UC-MSCs. TPL-primed UC-MSCs exhibited stronger anti-proliferative effect for activated CD4+ and CD8+ T cells in the allogeneic mixed lymphocyte reaction assay than the non-primed UC-MSCs. TPL-primed UC-MSCs promoted the expression of IDO-1 in the presence of IFN-γ, but TPL alone was not sufficient. Furthermore, TPL-primed UC-MSCs showed increased expression of PD-L1. Conclusively, upregulation of IDO-1 in the presence of IFN-γ and induction of PD-L1 enhances the immunosuppressive potency of TPL-primed UC-MSCs on the proliferation of activated T cells. Thus, TPL- primed MSCs may provide a novel immunosuppressive cell therapy.

WT1-specific CD8 + cytotoxic T cells with the capacity for antigen-specific expansion accumulate in the bone marrow in MDS.

Wilms' tumor 1 (WT1) is a tumor-associated antigen and immunotherapy target in myelodysplastic syndrome (MDS). Further information is needed on the characteristics of WT1-specific CD8 + T cells to develop immunotherapeutic strategies for MDS. To clarify the frequency, distribution, and phenotype of WT1-specific CD8 + T cells, which occur innately in MDS patients, we analyzed paired peripheral blood (PB) and bone marrow (BM) samples from 39 patients with MDS or acute myeloid leukemia with myelodysplasia-related changes. The median frequency of WT1 tetramer-binding CD8 + T cells in the CD8 + T cell population was 0.11% in PB and 0.18% in BM. A further tetramer assay combined with mixed lymphocyte peptide culture (MLPC assay) was used to detect functional WT1-specific CD8 + T cells that could respond to the WT1 peptide. Functional WT1-specific CD8 + T cells were detected in BM in 61% of patients, which was significantly higher than in PB (23%, p = 0.001). The frequency of these cells estimated by the MLPC assay was tenfold higher in BM than in PB. The majority of WT1 tetramer-binding CD8 + T cells in BM had a unique phenotype with co-expression of CD39 and CXCR4. These findings will facilitate the development of novel immunotherapeutic strategies for MDS.

Establishment of culturing system for ex-vivo expansion of angiogenic immature erythroid cells, and its application for treatment of patients with chronic severe lower limb ischemia.

Angiogenesis therapy by bone marrow-mononuclear cell implantation (BMI) has been utilized. We found that erythroid cells played an essential role in angiogenesis by BMI. We then tried to establish a novel cell therapy by implantation of ex vivo expanded immature erythroblasts cultured from hematopoietic stem/precursor cells. Immature to mature erythroblasts were purified from human bone marrow, and mRNA expression were analyzed. Strongly expressed VEGF and PLGF in immature erythroid cells decreased according to erythroid maturation. To expand very immature erythroid cells, we established a two-step culturing system, i.e., bone marrow cells were cultured in the presence of Flt-3L, SCF and TPO for 7 days, and the cells were further cultured in the presence of SCF, IGF-I and EPO for an additional 7 days. The in vivo angiogenic effects of implantation of the ex vivo expanded cells were stronger than that of BMI in mouse limb ischemia model. Three patients with severe chronic lower limb ischemia accompanied by Burger's disease or collagen arteritis were enrolled in a pilot clinical trial of the novel cell therapy by transplantation of ex-vivo expanded immature erythroid cells. In the clinical trial, most clinical symptoms such as rest pain and skin ulcers improved in 4 weeks, and did not recur in the one-year follow-up. No adverse events were observed in any of the patients. Moreover this novel cell therapy required only a small amount of bone marrow collection. Further enrollment of patients with chronic severe lower limb ischemia is necessary to confirm the efficacy and safety of this novel cell therapy, and to estimate the necessary amount of bone marrow aspirate.

WT1 peptide vaccine induces reduction in minimal residual disease in an Imatinib-treated CML patient.

How to treat CML patients who are resistant to inhibitors of BCR-ABL tyrosine kinase such as Imatinib is a very important and urgent issue in clinical hematology. Here, we report a case of Imatinib-treated CML in which intradermally administered WT1 peptide vaccine elicited WT1-specific immune responses and the resultant reduction in the persistent residual disease in co-administration of Imatinib. BCR-ABL mRNA levels were being maintained under the detection limit for 8 months since week 77 of vaccination. No adverse effects except local erythema at the injection sites were observed. The tetramer assay revealed that the decrease in BCR-ABL mRNA levels was associated with the increase in frequency of WT1-specific cytotoxic T lymphocytes, notably effector-memory type of that, in the patient's peripheral blood. The case presented here indicates that WT1 peptide vaccine may become a safe and cure-oriented therapy for CML patients who have residual disease regardless of the treatment with Imatinib.

WT1 peptide vaccination in combination with imatinib therapy for a patient with CML in the chronic phase.

Although tyrosine kinase inhibitors is effective for dramatically reducing CML cells, it might be difficult to eradicate completely the CML stem cells. We aimed to clarify the safety and effects of WT1 peptide vaccination in combination with imatinib therapy for a CML patient. A 51 year-old male with CML in CP, who showed a resistance against imatinib therapy for 2.5 years, began to be treated with 9 mer modified-type WT1 peptides in combination with standard dose of imatinib. Although every 2-week-administration of WT1 peptides for 22 weeks did not show definite effects on the quantification of bcr-abl transcripts, by changing the administration from every 2 weeks to 4 weeks bcr-abl transcripts decreased remarkably. After 11 months of every 4-week-administration of the peptides and 12 months post cessation of the peptides bcr-abl transcripts achieved to the level below detection by RQ/RT-PCR (complete molecular response). WT1/MHC tetramer(+)CD8(+) CTLs, which appeared after the second administration of WT1 peptides and remained more than 15 in number among 10(6) CD8(+) T cells throughout the administration of WT1 peptides, are still present in the blood on 14th month post cessation of the peptides. An in vitro study as to the cytotoxicity of lymphocytes induced by mixed lymphocyte peptide culture demonstrated that cultured lymphocytes possessed cytotoxicity against WT1 expressing leukemia cells and the cytotoxicity was WT1-specific and MHC class I restricted. The present study showed that WT1 peptide vaccination in combination with TKI is feasible and effective in the therapy for imatinib-resistant CML.