Hematopoiesis involves a series of lineage differentiation programs initiated in hematopoietic stem cells (HSCs) found in bone marrow (BM). To ensure lifelong hematopoiesis, various molecular mechanisms are needed to maintain the HSC pool. CCCTC-binding factor (CTCF) is a DNA-binding, zinc-finger protein that regulates the expression of its target gene by organizing higher order chromatin structures. Currently, the role of CTCF in controlling HSC homeostasis is unknown. Using a tamoxifen-inducible CTCF conditional knockout mouse system, we aimed to determine whether CTCF regulates the homeostatic maintenance of HSCs. In adult mice, acute systemic CTCF ablation led to severe BM failure and the rapid shrinkage of multiple c-Kit(hi) progenitor populations, including Sca-1⁺ HSCs. Similarly, hematopoietic system-confined CTCF depletion caused an acute loss of HSCs and highly increased mortality. Mixed BM chimeras reconstituted with supporting BM demonstrated that CTCF deficiency-mediated HSC depletion has both cell-extrinsic and cell-intrinsic effects. Although c-Kit(hi) myeloid progenitor cell populations were severely reduced after ablating Ctcf, c-Kit(int) common lymphoid progenitors and their progenies were less affected by the lack of CTCF. Whole-transcriptome microarray and cell cycle analyses indicated that CTCF deficiency results in the enhanced expression of the cell cycle-promoting program, and that CTCF-depleted HSCs express higher levels of reactive oxygen species (ROS). Importantly, in vivo treatment with an antioxidant partially rescued c-Kit(hi) cell populations and their quiescence. Altogether, our results suggest that CTCF is indispensable for maintaining adult HSC pools, likely by regulating ROS-dependent HSC quiescence.
Adult ; Animals ; Bone Marrow ; Cell Cycle ; Chimera ; Chromatin ; Fibrinogen* ; Hematopoiesis ; Hematopoietic Stem Cells* ; Homeostasis ; Humans ; Lymphoid Progenitor Cells ; Mice* ; Mice, Knockout ; Mortality ; Myeloid Progenitor Cells ; Reactive Oxygen Species

The objective of this study was to observe the expression of hoxc4 and hoxc6 genes in the process of differentiation of hematopoietic stem cell (HSC) to colony forming unit-T Lymphocyte (CFU-TL) in vitro. and to explore the possible mechanism of HCMV-induced maldevelopment of human cord blood CFU-TL on genetic level through effecting the differentiation progress by human cytomegalovirus (HCMV) with and/or all-trans retinoic acid (ATRA), Normal CFU-TL culture was used as blank control. After detection with MTT, mRNA expression levels in the human cord blood CFU-TL hoxc4 and hoxc6 genes following HCMV infection and ATRA treatment were detected by fluorogenic quantitative reserve transcription polymerize chain reaction (FQ-RT-PCR) method. HCMV of 10(6) plaque formation unit (PFU)/ml was diluted to 0.1 ml 10(5) PFU/ml and added into the infected group. The results showed that the expression of hoxc4 and hoxc6 genes in the differentiation process increased slightly on day 3, and were up to the most on day 7 (p < 0.05), while became lower on day 12 respectively in normal group, HCMV group and ATRA group. Compared with the expression of hoxc6, the expression of hoxc4 was obviously higher in each group (p < 0.05). Compared with the expression of hoxc4 and hoxc6 genes in normal group, the expressions of hoxc4 and hoxc6 in ATRA group were up-regulated remarkably (p < 0.05), while the expressions of hoxc4 and hoxc6 in group HCMV were down-regulated (p < 0.05). It is concluded that the regular expression of hoxc4 and hoxc6 genes mRNA appeared in each group. A positive co-relationship exits between hoxc4/hoxc6 genes and lymphocytic progenitor hematopoiesis. Compared with the expression of hoxc6 gene, the expression of hoxc4 gene is obviously higher in each group. HCMV can down-regulate the expression of hoxc4 and hoxc6 genes and lead to suppression effect on cell morphology, which confirms that the normal hematopoietic lineage determination and maturation rely on the stable and consistent expression of homeobox gene. At the same condition, ATRA (6 x 10(-8) mol/L at 60 nmol/ml) can up-regulate hoxc4 and hoxc6 genes expression. ATRA can up-regulate the expression of hoxc4 and hoxc6 genes.
Cell Line ; Cell Proliferation ; Cytomegalovirus ; genetics ; Cytomegalovirus Infections ; genetics ; Homeodomain Proteins ; genetics ; Humans ; Lymphoid Progenitor Cells ; cytology ; Tretinoin ; pharmacology

Hemophagocytic lymphohistiocytosis (HLH), although uncommon, is illustrated as a dramatic clinical presentation of multi-systemic inflammation due to the impaired activity of cytotoxic T-cell and NK cell. Etoposide, an important component of the HLH treatment, is thought to have a leukemogenic potential. Furthermore, it has been suggested that the underlying immunologic dysfunction in HLH might be involved in the occurrence of secondary leukemia. Only a few cases of secondary ALLs after HLH have been reported. We report herein a case of secondary precursor B-cell ALL which occurred after the treatment of HLH.
Etoposide ; Inflammation ; Killer Cells, Natural ; Leukemia ; Lymphohistiocytosis, Hemophagocytic ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Precursor Cells, B-Lymphoid ; T-Lymphocytes

We herein present a case of a 2-year-old girl with non-Hodgkin's lymphoma(NHL) of the lymphoblastic type involving cutaneous sites at the time of diagnosis. The histological finding was typical of lymphoblastic lymphoma. However, immunophenotypically, this lymphoma was not of the T-cell or B-cell type, although the vast majority of lymphoblastic lymphomas involving the skin are usually of the pre-B cell or T-ce11 type. Until now, there have been few reports of non-T, non-B primary cutaneous lymphoblastic lymphoma expressing surface CD10 and CD56 antigens as in this case.
Antigens, CD56 ; B-Lymphocytes ; Child, Preschool ; Diagnosis ; Female ; Humans ; Lymphoma ; Precursor Cell Lymphoblastic Leukemia-Lymphoma* ; Precursor Cells, B-Lymphoid ; Skin ; T-Lymphocytes

Swiprosin-1 exhibits the highest expression in CD8+ T cells and immature B cells and has been proposed to play a role in lymphocyte biology through actin remodeling. However, regulation of swiprosin-1 gene expression is poorly understood. Here we report that swiprosin-1 is up-regulated in T cells by PKC pathway. Targeted inhibition of the specific protein kinase C (PKC) isotypes by siRNA revealed that PKC-theta is involved in the expression of swiprosin-1 in the human T cells. In contrast, down-regulation of swiprosin-1 by A23187 or ionomycin suggests that calcium-signaling plays a negative role. Interestingly, swiprosin-1 expression is only reduced by treatment with NF-kappaB inhibitors but not by NF-AT inhibitor, suggesting that the NF-kappaB pathway is critical for regulation of swiprosin-1 expression. Collectively, these results suggest that swiprosin-1 is a PKC-theta-inducible gene and that it may modulate the late phase of T cell activation after antigen challenge.
Actins ; Biology ; Calcimycin ; Down-Regulation ; Gene Expression ; Humans ; Ionomycin ; Lymphocytes ; NF-kappa B ; Precursor Cells, B-Lymphoid ; Protein Kinase C ; Protein Kinases ; RNA, Small Interfering ; T-Lymphocytes

BACKGROUND: Precursor T-cell acute lymphoblastic leukemia (T-ALL) has worse prognosis than B-cell ALL. We aimed to evaluate prognostic variables in pediatric T-ALL. METHODS: Medical records of 36 T-ALL patients (27 males and 9 females; median age at diagnosis, 10.6 years) diagnosed and treated at Asan Medical Center from 2001 to 2017 were reviewed. Six patients (16.7%) had early T-cell precursor ALL (ETP-ALL). Most patients received the Children's Cancer Group-1882 (CCG1882) or Korean multicenter high risk ALL (ALL0601) protocols and prophylactic cranial irradiation. Clinical features at presentation, response to therapy, and treatment outcomes were analyzed. RESULTS: The six patients with ETP-ALL and 17 of 30 with non-ETP-ALL received CCG1882 or ALL0601 chemotherapy. Three patients, including two with ETP-ALL, did not achieve complete remission after induction. Rapid early response during induction was achieved by 26 patients. Five year overall survival (OS) and event free survival (EFS) rates were 71.4% and 70.2%, respectively. ETP-ALL and slow early response during induction were significant adverse prognostic factors, while hyperleukocytosis at diagnosis was not. CCG1882/ALL0601 chemotherapy resulted in superior survival (OS: 78.9%, EFS: 73.3%) compared with CCG1901 chemotherapy (OS: 64.3%, EFS: 64.3%), and patients undergoing prophylactic cranial irradiation had superior EFS to non-radiated patients. CONCLUSION: A high risk ALL protocol with intensified post-remission therapy, including prophylactic cranial irradiation, conferred T-ALL survival outcomes comparable with those of Western studies. Further treatment intensification should be considered for patients with ETP-ALL and slow induction responders. Additionally, CNS-directed treatment intensification, without prophylactic cranial irradiation, is needed.
B-Lymphocytes ; Chungcheongnam-do ; Cranial Irradiation ; Diagnosis ; Disease-Free Survival ; Drug Therapy ; Female ; Humans ; Male ; Medical Records ; Precursor Cell Lymphoblastic Leukemia-Lymphoma* ; Precursor Cells, T-Lymphoid ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma ; Prognosis ; T-Lymphocytes*

Operational tolerance (OT), defined as maintaining stable graft function without immunosuppression after transplant surgery, is an ideal goal for kidney transplant recipients (KTRs). Recent investigations have demonstrated the distinctive features of B cells, T cells, and dendritic cell-related gene signatures and the distributions of circulating lymphocytes in these patients; nonetheless, substantial heterogeneities exist across studies. This study was conducted to determine whether previously reported candidate gene biomarkers and the profiles of lymphocyte subsets of OT could be applied in Korean KTRs. Peripheral blood samples were collected from 153 patients, including 7 operationally tolerant patients. Quantitative real-time PCR and flow cytometry were performed to evaluate gene expression and lymphocyte subsets, respectively. Patients with OT showed significantly higher levels of B cell-related gene signatures (IGKV1D-13 and IGKV4-1), while T cell-related genes (TOAG-1) and dendritic cell-related genes (BNC2, KLF6, and CYP1B1) were not differentially expressed across groups. Lymphocyte subset analyses also revealed a higher proportion of immature B cells in this group. In contrast, the distributions of CD4⁺ T cells, CD8⁺ T cells, mature B cells, and memory B cells showed no differences across diagnostic groups. An OT signature, generated by the integration of IGKV1D-13, IGKV4-1, and immature B cells, effectively discriminated patients with OT from those in other diagnostic groups. Finally, the OT signature was observed among 5.6% of patients who had stable graft function for more than 10 years while on immunosuppression. In conclusion, we validated an association of B cells and their related signature with OT in Korean KTRs.
B-Lymphocytes ; Biomarkers ; Flow Cytometry ; Gene Expression ; Humans ; Immunosuppression ; Kidney Transplantation ; Kidney* ; Lymphocyte Subsets ; Lymphocytes ; Memory ; Precursor Cells, B-Lymphoid ; Real-Time Polymerase Chain Reaction ; RNA, Messenger ; T-Lymphocytes ; Transplant Recipients* ; Transplants

BACKGROUND: Precursor B-cell acute lymphoblastic leukemia (B-cell ALL) is the most common neoplasm in children and is characterized by genetic and epigenetic aberrations in hematopoietic transcription factor (TF) genes. This study evaluated promoter DNA methylation and aberrant expression levels of early- and late-acting hematopoietic TF genes homeobox A4 and A5 (HOXA4 and HOXA5), Meis homeobox 1 (MEIS1), T-cell acute lymphocytic leukemia 1 (TAL1), and interferon regulatory factors 4 and 8 (IRF4 and IRF8) in pediatric B-cell ALL. METHODS: Blood samples of 38 ALL patients and 20 controls were obtained. DNA was treated with sodium bisulfite and DNA methylation level of HOXA4, HOXA5, MEIS1, TAL1, IRF4, and IRF8 was assessed using quantitative methylation-specific polymerase chain reaction (PCR). Relative gene expression was measured using quantitative reverse transcription-PCR. RESULTS: Aberrant methylation of TAL1, IRF8, MEIS1, and IRF4 was observed in 26.3%, 7.9%, 5.3%, and 2.6% patients, respectively, but not in controls. HOXA4 and HOXA5 were methylated in some controls and hypermethylated in 16% and 5% patients, respectively. IRF8, MEIS1, and TAL1 expression was lower in patients than in controls. MEIS1 expression was inversely correlated with white blood cell (WBC) count. HOXA4 expression was down-regulated in patients with high risk according to the National Cancer Institute (NCI) classification. TAL1 methylation was slightly elevated in patients aged >9 years and in patients showing relapse, suggesting its potential prognostic value. CONCLUSION: Aberrant methylation and expression of the selected hematopoietic genes were correlated with demographic/clinical prognostic factors of pediatric ALL, such as age, WBC count, and NCI risk classification.
B-Lymphocytes* ; Child ; Classification ; DNA ; DNA Methylation ; Epigenomics ; Gene Expression ; Genes, Homeobox ; Humans ; Interferon Regulatory Factors ; Leukocytes ; Methylation* ; National Cancer Institute (U.S.) ; Polymerase Chain Reaction ; Precursor Cell Lymphoblastic Leukemia-Lymphoma* ; Precursor Cells, B-Lymphoid ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma ; Recurrence ; Sodium ; Transcription Factors

<b>OBJECTIVEb>To study the effect of rapamycin in inducing naïve murine effector T cell (Teff) convert to regulatory T cell (Treg) in vitro.

<b>METHODSb>The forkhead box protein 3 (FoxP3) negative Teff were isolated and purified from the spleen and lymph node of C57 BL/6 murines aged 6-8 weeks, then Teff were cultured in three groups with mature dendritic cells (mDC), B cells, and plate coated Anti-CD3. In addition, the control wells and the test wells were prepared in each group, rapamycin were not added in the control wells but added in the test wells with concentrations of 1, 10, 50, and 100 nmol/L. Percentages of FoxP3 positive Treg were examined by flow cytometry after 4 days in Anti-CD3 group and after 6 days in the other two groups.

<b>RESULTSb>As shown by the flow cytometry, the percentages of FoxP3 positive Treg were as follows in three group: in the mDC group, it was 0.01% in the control well and 0.39%, 0.47%, 0.34%, and 0.26% in test wells; in B cell group, it was 0.01% in the control wells and 5.56%, 5.89%, 7.15%, and 4.72% in the test wells; in Anti-CD3 group, it was 0.93% in the control wells and 1.35%, 1.07%, 1.02%, and 1.19% in test wells. No significant difference was found between the test wells and control wells in the mDC group and Anti-CD3 group; however, the percentages of FoxP3 positive Treg was significantly different between the test wells and control wells in the B cell group (P < 0.01).

<b>CONCLUSIONb>When B cell is acted as the antigen-presenting cell, rapamycin can effectively induce Teff convert to Treg in vitro.

Animals ; B-Lymphocytes ; cytology ; drug effects ; immunology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Dendritic Cells ; cytology ; drug effects ; immunology ; Flow Cytometry ; Forkhead Transcription Factors ; immunology ; Mice ; Mice, Inbred C57BL ; Mice, Inbred DBA ; Precursor Cells, T-Lymphoid ; cytology ; drug effects ; immunology ; Sirolimus ; pharmacology ; T-Lymphocyte Subsets ; cytology ; drug effects ; immunology ; T-Lymphocytes, Regulatory ; cytology ; drug effects ; immunology

Pneumatosis intestinalis (PI) is an imaging phenomenon that represents air in the bowel wall. The cause of PI is variable, although specific etiologic factors remain unknown. It is an infrequent complication in leukemia patients and is associated with several medical and surgical conditions. PI often represents a benign condition, but it can also require surgery. Therefore, the assessment of PI with or without complications can be difficult. Herein, we report on an unusual case of a 63 year-old woman with refractory acute precursor B-cell lymphoblastic leukemia-lymphoma who presented with PI resulting from the leukemic process, and finally expired due to sepsis.
Female ; Humans ; Leukemia ; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma ; Precursor Cells, B-Lymphoid ; Sepsis