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Background: Target lesion failure (TLF) remains an issue with contemporary drug-eluting stents. The dual-therapy sirolimus-eluting and CD34 antibody-coated COMBO stent (DTS) was designed to improve early healing., Aims: We aimed to compare the 3-year outcomes of the DTS and the sirolimus-eluting Orsiro stent (SES) in all-comer patients treated with percutaneous coronary intervention., Methods: The SORT OUT X trial is a prospective multicentre randomised clinical trial with a registry-based follow-up comparing DTS and SES. The primary endpoint, TLF, is a composite of cardiac death, myocardial infarction or target lesion revascularisation (TLR)., Results: A total of 3,146 patients were randomised to treatment with the DTS (1,578 patients) or the SES (1,568 patients). At 3 years, an intention-to-treat analysis showed that 155 patients (9.8%) who were assigned the DTS and 118 patients (7.5%) who were assigned the SES met the primary endpoint (incidence rate ratio for TLF=1.33, 95% confidence interval: 1.04-1.70; p=0.02). This difference was caused by a significantly higher TLF rate in the DTS group compared to the SES group within the first year, which was mainly explained by a higher incidence of TLR in the DTS group compared to the SES group. Of note, the TLF rates were almost identical from 1 year to 3 years in both stent groups., Conclusions: At 3 years, the SES was superior to the DTS, mainly because the DTS was associated with an increased risk of TLF within the first year but not from 1 to 3 years., Clinicaltrials: gov: NCT03216733.

Monitoring of donor chimerism (DC) may detect early relapse following allogeneic hematopoietic stem cell transplantation (allo-SCT) for acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). Most centers use unfractionated peripheral blood or T-cells to monitor DC, although CD34 + DC may be more predictive. The limited adoption of CD34 + DC may be due to the lack of detailed, comparative studies. To address this knowledge gap, we compared peripheral blood CD34 + and CD3 + DC in 134 patients who underwent allo-SCT for AML or MDS. In July 2011, the Alfred Hospital Bone Marrow Transplantation Service adopted routine monitoring of DC in the lineage-specific CD34 + and CD3 + cell subsets from peripheral blood at 1, 2, 3, 4, 6, 9, and 12 months post-transplantation for AML or MDS. Immunologic interventions, including rapid withdrawal of immunosuppression, azacitidine, and donor lymphocyte infusion, were prespecified for CD34 + DC ≤80%. Overall, CD34 + DC ≤80% detected 32 of 40 relapses (positive predictive value [PPV], 68%; negative predictive value [NPV], 91%), compared with 13 of 40 relapses for CD3 + DC ≤80% (PPV, 52%; NPV, 75%). Receiver operating characteristic analysis showed the superiority of CD34 + DC, with the greatest value at day 120 post-transplantation. CD3 + DC provided additional value in only 3 cases, preceding CD34 + DC ≤80% by 1 month. We further show that the CD34 + DC sample can be used to detect NPM1 mut , with the combination of CD34 + DC ≤80% and NPM1 mut identifying the highest risk of relapse. Among the 24 patients in morphologic remission at the time of CD34 + DC ≤80%, 15 (62.5%) responded to immunologic interventions (rapid withdrawal of immunosuppression, azacitidine, or donor lymphocyte infusion) with recovery of CD34 + DC >80%, and 11 of these patients remained in complete remission for a median of 34 months (range, 28 to 97 months). In contrast, the other 9 patients did not respond to the clinical intervention and relapsed within a median of 59 days after detecting CD34 + DC ≤80%. The CD34 + DC was significantly higher in responders than in nonresponders (median, 72% versus 56%; P = .015, Mann-Whitney U test). Overall, monitoring of CD34 + DC was considered clinically useful (early diagnosis of relapse enabling preemptive therapy or predicting low risk of relapse) in 107 of 125 evaluable patients (86%). Our findings show that peripheral blood CD34 + DC is feasible and superior to CD3 + DC for predicting relapse. It also provides a source of DNA for measurable residual disease testing, which may further stratify the risk of relapse. If validated by an independent cohort, our results suggest that CD34 + should be used in preference to CD3 + DC for detecting early relapse and guiding immunologic interventions following allo-SCT for AML or MDS., (Copyright © 2023 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Background: The DNA-repair enzyme Artemis is essential for rearrangement of T- and B-cell receptors. Mutations in DCLRE1C , which encodes Artemis, cause Artemis-deficient severe combined immunodeficiency (ART-SCID), which is poorly responsive to allogeneic hematopoietic-cell transplantation., Methods: We carried out a phase 1-2 clinical study of the transfusion of autologous CD34+ cells, transfected with a lentiviral vector containing DCLRE1C , in 10 infants with newly diagnosed ART-SCID. We followed them for a median of 31.2 months., Results: Marrow harvest, busulfan conditioning, and lentiviral-transduced CD34+ cell infusion produced the expected grade 3 or 4 adverse events. All the procedures met prespecified criteria for feasibility at 42 days after infusion. Gene-marked T cells were detected at 6 to 16 weeks after infusion in all the patients. Five of 6 patients who were followed for at least 24 months had T-cell immune reconstitution at a median of 12 months. The diversity of T-cell receptor β chains normalized by 6 to 12 months. Four patients who were followed for at least 24 months had sufficient B-cell numbers, IgM concentration, or IgM isohemagglutinin titers to permit discontinuation of IgG infusions. Three of these 4 patients had normal immunization responses, and the fourth has started immunizations. Vector insertion sites showed no evidence of clonal expansion. One patient who presented with cytomegalovirus infection received a second infusion of gene-corrected cells to achieve T-cell immunity sufficient for viral clearance. Autoimmune hemolytic anemia developed in 4 patients 4 to 11 months after infusion; this condition resolved after reconstitution of T-cell immunity. All 10 patients were healthy at the time of this report., Conclusions: Infusion of lentiviral gene-corrected autologous CD34+ cells, preceded by pharmacologically targeted low-exposure busulfan, in infants with newly diagnosed ART-SCID resulted in genetically corrected and functional T and B cells. (Funded by the California Institute for Regenerative Medicine and the National Institute of Allergy and Infectious Diseases; ClinicalTrials.gov number, NCT03538899.)., (Copyright © 2022 Massachusetts Medical Society.)

Objectives: To compare the efficacy and safety of the dual therapy CD34 antibody-covered sirolimus-eluting Combo stent (DTS) and the sirolimus-eluting Orsiro stent (SES) in patients with and without diabetes mellitus (DM) included in the Scandinavian Organization for Randomized Trials with Clinical Outcome (SORT OUT) X study., Background: The incidence of target lesion failure (TLF) after treatment with modern drug-eluting stents has been reported to be significantly higher in patients with DM when compared to patients without DM. Thus, whether the results from the SORT OUT X study apply to patients with and without DM remains unknown., Methods: In total 3146 patients were randomized to stent implantation with DTS (n = 1578; DM: n = 279) or SES (n = 1568; DM: n = 271). The primary end point, TLF, was a composite of cardiac death, target-lesion myocardial infarction (MI), or target lesion revascularization (TLR) within 1 year., Results: At 1 year, the rate of TLF was increased in the DTS group compared to the SES group, both among patients with DM (9.3% vs. 4.8%; risk difference: 4.5%; incidence rate ratio: 1.99, 95% confidence interval [CI]: 1.02-3.90) and without DM (5.7% vs. 3.5%; incidence rate ratio: 1.67, 95% CI: 1.15-2.42). The differences were mainly explained by higher rates of TLR., Conclusion: Compared to the SES, the DTS was associated with an increased risk of TLF at 12 months in patients with and without DM. The differences were mainly explained by higher rates of TLR, whereas rates of cardiac death and target lesion MI did not differ significantly between the two stent groups in patients with or without DM., (© 2022 The Authors. Catheterization and Cardiovascular Interventions published by Wiley Periodicals LLC.)

Kinase signaling fuels growth of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Yet its role in leukemia initiation is unclear and has not been shown in primary human hematopoietic cells. We previously described activating mutations in interleukin-7 receptor alpha (IL7RA) in poor-prognosis "ph-like" BCP-ALL. Here we show that expression of activated mutant IL7RA in human CD34 + hematopoietic stem and progenitor cells induces a preleukemic state in transplanted immunodeficient NOD/LtSz-scid IL2Rγ null mice, characterized by persistence of self-renewing Pro-B cells with non-productive V(D)J gene rearrangements. Preleukemic CD34 + CD10 high CD19 + cells evolve into BCP-ALL with spontaneously acquired Cyclin Dependent Kinase Inhibitor 2 A (CDKN2A) deletions, as commonly observed in primary human BCP-ALL. CRISPR mediated gene silencing of CDKN2A in primary human CD34 + cells transduced with activated IL7RA results in robust development of BCP-ALLs in-vivo. Thus, we demonstrate that constitutive activation of IL7RA can initiate preleukemia in primary human hematopoietic progenitors and cooperates with CDKN2A silencing in progression into BCP-ALL., (© 2022. The Author(s).)

Some previous researches raised the possibility of a novel acute myeloid leukemia (AML) entity presenting cup-like cytomorphology with mutations of both FLT3 and NPM1 or one of them. However, the clinical implications of this subtype remain unknown. We describe a 63-year-old patient belonging to this distinct AML subtype, who presented similar features of acute promyelocytic leukemia (APL) including nuclear morphology, negative for CD34 and HLA-DR, and abnormal coagulation. He had no response to both arsenic trioxide and CAG regimen (cytarabine, aclarubicin, and G-CSF). Given that the patient carried the FLT3-ITD mutation, we switched to a pilot treatment of FLT3 inhibitor sorafenib combined with low-dose cytarabine (LDAC). To date, the patient achieved durable complete remission over 58 months. These findings suggest that AML with cup-like blasts and FLT3-ITD and NPM1 mutations mimic APL, and the prognosis of this subtype may be improved by sorafenib combined with LDAC., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose: Chondrocytes, isolated from articular cartilage, are routinely utilized in cell-based therapeutics for the treatment of cartilage pathologies. However, restoration of the biological tissue faces hindrance due to the formation of primarily fibrocartilaginous repair tissue. Chondroprogenitors have been reported to display superiority in terms of their chondrogenic potential and lesser proclivity for hypertrophy. In line with our recent results, comparing chondroprogenitors and chondrocytes, we undertook isolation of progenitors from the general pool of chondrocytes, based on surface marker expression, namely, CD166, CD34, and CD146, to eliminate off-target differentiation and generate cells of stronger chondrogenic potential. This study aimed to compare chondrocytes, chondroprogenitors, CD34-CD166+CD146+ sorted chondrocytes, and CD34-CD166+CD146- sorted chondrocytes., Methods: Chondrocytes obtained from 3 human osteoarthritic knee joints were subjected to sorting, to isolate CD166+ and CD34- subsets, and then were further sorted to obtain CD146+ and CD146- cells. Chondrocytes and fibronectin adhesion-derived chondroprogenitors served as controls. Assessment parameters included reverse transcriptase polymerase chain reaction for markers of chondrogenesis and hypertrophy, trilineage differentiation, and total GAG/DNA content., Results: Based on gene expression analysis, CD34-CD166+CD146+ sorted chondrocytes and chondroprogenitors displayed comparability and significantly higher chondrogenesis with a lower tendency for hypertrophy when compared to chondrocytes and CD34-CD166+CD146- sorted chondrocytes. The findings were also reiterated in multilineage potential differentiation with the 146+ subset and chondroprogenitors displaying lower calcification and chondroprogenitors displaying higher total GAG/DNA content compared to chondrocytes and 146- cells., Conclusion: This unique progenitor-like population based on CD34-CD166+CD146+ sorting from chondrocytes exhibits efficient potential for cartilage repair and merits further evaluation for its therapeutic application.

Allogeneic hematopoeitic cell transplantation (allo-HCT) is the only curative treatment for myelofibrosis (MF). We evaluate the impact of various factors on survival outcomes post-transplant in MF. Data of 89 consecutive MF patients (primary 47%) who underwent allo-HCT between 2005 and 2018 was evaluated. Fifty-four percent patients had received JAK1/2 inhibitors (JAKi) pre-HCT. The median CD34 count was 7.1x10 6 cells/kg. Graft failure was seen in 10% of the patients. Grade 3-4 acute GVHD (aGVHD) and moderate/severe chronic graft versus host disease (cGVHD) occurred in 24% and 40% patients, respectively. Two-year overall survival (OS) and relapse free survival (RFS) were 51% and 43%, respectively. Cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) at 2 years were 11% and 46%, respectively. Higher CD34 cell dose (≤5 × 10 6 cells/kg vs 5-9 or ≥9 × 10 6  cells/kg) and lower pre-HCT ferritin (

Chronic myelomonocytic leukemia (CMML) is a stem cell-derived neoplasm characterized by dysplasia, uncontrolled expansion of monocytes, and substantial risk to transform to secondary acute myeloid leukemia (sAML). So far, little is known about CMML-initiating cells. We found that leukemic stem cells (LSC) in CMML reside in a CD34 + /CD38 - fraction of the malignant clone. Whereas CD34 + /CD38 - cells engrafted NSGS mice with overt CMML, no CMML was produced by CD34 + /CD38 + progenitors or the bulk of CD34 - monocytes. CMML LSC invariably expressed CD33, CD117, CD123 and CD133. In a subset of patients, CMML LSC also displayed CD52, IL-1RAP and/or CLL-1. CMML LSC did not express CD25 or CD26. However, in sAML following CMML, the LSC also expressed CD25 and high levels of CD114, CD123 and IL-1RAP. No correlations between LSC phenotypes, CMML-variant, mutation-profiles, or clinical course were identified. Pre-incubation of CMML LSC with gemtuzumab-ozogamicin or venetoclax resulted in decreased growth and impaired engraftment in NSGS mice. Together, CMML LSC are CD34 + /CD38 - cells that express a distinct profile of surface markers and target-antigens. During progression to sAML, LSC acquire or upregulate certain cytokine receptors, including CD25, CD114 and CD123. Characterization of CMML LSC should facilitate their enrichment and the development of LSC-eradicating therapies., (© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)

Haploidentical stem cell transplantation (haploSCT) has advanced to a common procedure for treating patients with hematological malignancies and immunodeficiency diseases. However, cure is seriously hampered by cytomegalovirus (CMV) infections and delayed immune reconstitution for the majority of haploidentical transplant recipients compared to HLA-matched stem cell transplantation. Three major approaches, including in vivo T-cell depletion (TCD) using antithymocyte globulin for haploSCT ( in vivo TCD-haploSCT), ex vivo TCD using CD34 + positive selection for haploSCT ( ex vivo TCD-haploSCT), and T-cell replete haploSCT using posttransplant cyclophosphamide (PTCy-haploSCT), are currently used worldwide. We provide an update on CMV infection and CMV-specific immune recovery in this fast-evolving field. The progress made in cellular immunotherapy of CMV infection after haploSCT is also addressed. Groundwork has been prepared for the creation of personalized avenues to enhance immune reconstitution and decrease the incidence of CMV infection after haploSCT., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Luo, Zhu, Chen, Shui and Liu.)

Innate lymphoid cells (ILCs) are critical effectors of innate immunity and inflammation, whose development and activation pathways make for attractive therapeutic targets. However, human ILC generation has not been systematically explored, and previous in vitro investigations relied on the analysis of few markers or cytokines, which are suboptimal to assign lineage identity. Here, we developed a platform that reliably generated human ILC lineages from CD34 + hematopoietic progenitors derived from cord blood and bone marrow. We showed that one culture condition is insufficient to generate all ILC subsets, and instead, distinct combination of cytokines and Notch signaling are essential. The identity of natural killer (NK)/ILC1s, ILC2s, and ILC3s generated in vitro was validated by protein expression, functional assays, and both global and single-cell transcriptome analysis, recapitulating the signatures and functions of their ex vivo ILC counterparts. These data represent a resource to aid in clarifying ILC biology and differentiation., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Introduction: Periodontal disease presents a challenge for modern medicine, and research on the use of stem cells as a treatment is currently underway., Material and Methods: The study included 45 patients who were given a thorough physical examination. Additionally, an evaluation of their medical history of the disease, degree of progression of periodontal disease, and the level of CRP in the blood was carried out. Patients were divided into 4 groups: 4 patients were in the first group with no periodontal disease, 8 patients in the second group with a moderate level, 20 patients in the third group with an advanced level, and 13 patients in the fourth group were toothless. For each group, the use of stem cells as a treatment of antibody-labeled CD34+ stem cells, lymphocytes, and leukocytes was conducted., Results: A statistically significant positive correlation was observed in CD34+ stem cells in proportion to lymphocytes in the moderate (0.80), in the advanced (0.75), and in the toothless groups (0.70). The ratio of CD34+ stem cells to leukocytes was statistically significant in the toothless group (0.92) and in the advanced group (0.91). A statistically significant increase was noted in the level of CRP in the previously mentioned groups of patients, and the highest concentration of CD34+ stem cells in the advanced group., Conclusions: The highest concentration of CD34+ cells was observed in the group of patients with advanced periodontal disease.

Paraquat (PQ) is a redox cycling herbicide known for its acute toxicity in humans. Airway parenchymal cells have been identified as primary sites for PQ accumulation, tissue inflammation and cellular injury. However, the role of immune cells in PQ induced tissue injury is largely unknown. To explore this further, primary cultures of human CD34+ stem cell derived macrophages (MC cd34 ) and dendritic cells (DC cd34 ) were established and characterised using RNA-Seq profiling. The impact of PQ on DC cd34 and MC cd34 cytotoxicity revealed increased effect within DC cd34 cultures. PQ toxicity mechanisms were examined using sub-cytotoxic concentrations and TempO-seq transcriptomic assays. Comparable increases for several stress response pathway (NFE2L2, NF-kB and HSF) dependent genes were observed across both cell types. Interestingly, PQ induced unfolded protein response (UPR), p53, Irf and DC maturation genes in DC cd34 but not in MC cd34 . Further exploration of the immune modifying potential of PQ was performed using the common allergen house dust mite (HD). Co-treatment of PQ and HD resulted in enhanced inflammatory responses within MC cd34 but not DC cd34 . These results demonstrate immune cell type differential responses to PQ, that may underlie aspects of acute toxicity and susceptibility to inflammatory disease., (Copyright © 2021. Published by Elsevier Ltd.)

Objectives: This study aims to retrospectively assess C-lectin-like molecule 1 (CLL-1) bimodal expression on CD34+ blasts in acute myeloid leukemia (AML) patients (total N = 306) and explore potential CLL-1 bimodal associations with leukemia and patient-specific characteristics., Methods: Flow cytometry assays were performed to assess the deeper immunophenotyping of CLL-1 bimodality. Cytogenetic analysis was performed to characterize the gene mutation on CLL-1-negative subpopulation of CLL-1 bimodal AML samples., Results: The frequency of a bimodal pattern of CLL-1 expression of CD34 + blasts ranged from 8% to 65% in the different cohorts. Bimodal CLL-1 expression was most prevalent in patients with MDS-related AML (P = .011), ELN adverse risk (P = .002), NPM1 wild type (WT, P = .049), FLT3 WT (P = .035), and relatively low percentages of leukemia-associated immunophenotypes (P = .006). Additional immunophenotyping analysis revealed the CLL-1 - subpopulation may consist of pre-B cells, immature myeloblasts, and hematopoietic stem cells. Furthermore, (pre)-leukemic mutations were detected in both CLL-1 + and CLL-1 - subfractions of bimodal samples (N = 3)., Conclusions: C-lectin-like molecule 1 bimodality occurs in about 25% of AML patients and the CLL-1 - cell population still contains malignant cells, hence it may potentially limit the effectiveness of CLL-1-targeted therapies and warrant further investigation., (© 2021 Genentech Inc. European Journal of Haematology published by John Wiley & Sons Ltd.)

T cells are pivotal effectors of the immune system and can be harnessed as therapeutics for regenerative medicine and cancer immunotherapy. An unmet challenge in the field is the development of a clinically relevant system that is readily scalable to generate large numbers of T-lineage cells from hematopoietic stem/progenitor cells (HSPCs). Here, we report a stromal cell-free, microbead-based approach that supports the efficient in vitro development of both human progenitor T (proT) cells and T-lineage cells from CD34 + cells sourced from cord blood, GCSF-mobilized peripheral blood, and pluripotent stem cells (PSCs). DL4-μbeads, along with lymphopoietic cytokines, induce an ordered sequence of differentiation from CD34 + cells to CD34 + CD7 + CD5 + proT cells to CD3 + αβ T cells. Single-cell RNA sequencing of human PSC-derived proT cells reveals a transcriptional profile similar to the earliest thymocytes found in the embryonic and fetal thymus. Furthermore, the adoptive transfer of CD34 + CD7 + proT cells into immunodeficient mice demonstrates efficient thymic engraftment and functional maturation of peripheral T cells. DL4-μbeads provide a simple and robust platform to both study human T cell development and facilitate the development of engineered T cell therapies from renewable sources., (© 2021. The Author(s).)

Background: PGF is historically associated with high morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT)., Methods: In this study, we report our multicenter experience on stem cell boost (SCB) for PGF, or incomplete donor engraftment, in 16 pediatric patients. Donors were HLA-matched siblings (n = 4), unrelated donors (n = 11), or haploidentical family members (n = 1). Ten patients had two-lineage cytopenia, 5 had one-lineage cytopenia, and 1 had poor immunological reconstitution together with a low percentage of donor cell engraftment. A median of 6.6x10 6 selected CD34+/Kg was infused after 194 days from allo-HSCT (48-607)., Results: In 4 out of 5 patients, one-lineage cytopenia was resolved, while among the 10 patients with two-lineage cytopenia, 4 resolved both cytopenia, 5 resolved one-lineage, and one did not respond. All patients reverted their mixed chimera to full donor chimera. OS was 56%, transplant-related mortality (TRM) 32%, and RI 12%. The main causes of failure were related to infections with 4 out of 7 deaths caused by this., Conclusions: SCB may rescue over 50% of patients with PGF after allo-HSCT. An earlier treatment may reduce the infectious complications and improve survival., (© 2020 Wiley Periodicals LLC.)

Accurate knowledge of expression patterns/levels of commonly used MRD markers in regenerative normal-B-cell-precursors (BCP) is highly desirable to distinguish leukemic-blasts from regenerative-BCP for multicolor flow cytometry (MFC)-based measurable residual disease (MRD) assessment in B-lymphoblastic leukemia (B-ALL). However, the data highlighting therapy-related immunophenotypic-shift in regenerative-BCPs is scarce and limited to small cohort. Herein, we report the in-depth evaluation of immunophenotypic shift in regenerative-BCPs from a large cohort of BALL-MRD samples. Ten-color MFC-MRD analysis was performed in pediatric-BALL at the end-of-induction (EOI), end-of-consolidation (EOC), and subsequent-follow-up (SFU) time-points. We studied normalized-mean fluorescent intensity (nMFI) and coefficient-of-variation of immunofluorescence (CVIF) of CD10, CD19, CD20, CD34, CD38, and CD45 expression in regenerative-BCP (early, BCP1 and late, BCP2) from 200 BALL-MRD samples, and compared them with BCP from 15 regenerating control (RC) TALL-MRD samples and 20 treatment-naïve bone-marrow control (TNSC) samples. Regenerative-BCP1 showed downregulation in CD10 and CD34 expression with increased CVIF and reduced nMFI (p < 0.001), upregulation of CD20 with increased nMFI (p = 0.014) and heterogeneous CD45 expression with increased CVIF (p < 0.001). Immunophenotypic shift was less pronounced in the BCP2 compared to BCP1 compartment with increased CVIF in all but CD45 (p < 0.05) and reduced nMFI only in CD45 expression (p = 0.005). Downregulation of CD10/CD34 and upregulation of CD20 was higher at EOI than EOC and SFU time-points (p < 0.001). Regenerative-BCPs are characterized by the significant immunophenotypic shift in commonly used B-ALL-MRD markers, especially CD10 and CD34 expression, as compared to treatment-naïve BCPs. Therefore, the templates/database for BMRD analysis must be developed using regenerative-BCP., (© 2020 International Clinical Cytometry Society.)

This protocol describes how to evaluate cellular metabolic state, including the glycolytic activity, in live CD34 + hematopoietic stem/progenitor cells (HSPCs) upon depletion of a specific target gene. We detail the procedure of enriching mononuclear cells from human umbilical cord blood samples, isolation of CD34 + HSPCs using positive immunomagnetic separation, and the analysis of glycolytic activity in lentivirally transduced CD34 + HSPCs using Seahorse Assay. This protocol can be applied to evaluate potential aerobic glycolysis gene targets for cancer therapy. For complete details on the use and execution of this protocol, please refer to Qing et al. (2021)., Competing Interests: J.C. is a scientific founder of Genovel Biotech Corp. and holds equities with the company and is also a scientific advisor for Race Oncology., (© 2021 The Authors.)

During autologous stem cell transplant, granulocyte colony-stimulating factors (G-CSF) serve the integral role of mobilizing hematopoietic cells into the peripheral blood for subsequent collection by leukapheresis. Filgrastim (Neupogen®) is a G-CSF and affects hematopoietic cells by stimulating growth and differentiation of neutrophils. Filgrastim-sndz (Zarxio®), a biosimilar of filgrastim, received landmark approval as the first biosimilar product approved by the FDA in the United States. As a result of the recent FDA approval, our medical center made the conversion in August 2016 from using filgrastim to filgrastim-sndz to provide patients the same benefits of the filgrastim injection at a reduced cost. This retrospective, observational cohort study evaluated the comparative efficacy of the filgrastim-sndz biosimilar in 147 patients who underwent mobilization prior to stem cell transplant with filgrastim between 1 August 2015 and 31 July 2016 or filgrastim-sndz between 1 September 2016 and 30 November 2017. The mean number of CD 34 cells collected during apheresis was 7.38 × 10 6 in the filgrastim group and 8.86 × 10 6 in the filgrastim-sndz group. Filgrastim-sndz was significantly non-inferior, as the difference between filgrastim and filgrastim-sndz was -1.48 × 10 6 with an upper 95% confidence bound equal to -0.24 × 10 6 that did not include the non-inferiority margin of 1 × 10 6 ( p  = 0.0006). The median number of days of apheresis was 2 in both groups ( p = 0.3273). In conclusion, the biosimilar product was non-inferior for mobilization and the conversion from filgrastim to filgrastim-sndz afforded patients similar efficacy for mobilization in stem cell transplant at a reduced cost.

We characterized the tissue repair response after penetrating traumatic brain injury (pTBI) in this study. Seventy specific pathogen-free Kunming mice were randomly divided into the following groups: normal control, 1, 3, 7, 15, 21, and 30 days after pTBI. Hematoxylin and eosin (H&E) staining, immunohistochemistry, and immunofluorescence were performed to examine and monitor brain tissue morphology, and the distribution and expression of lymphatic-specific markers lymphatic vessel endothelial receptor-1 (LYVE-1), hematopoietic precursor cluster of differentiation 34 (CD34) antigen, and Prospero-related homeobox-1 (PROX1) protein. H&E staining revealed that damaged and necrotic tissues observed on day 1 at and around the injury site disappeared on day 7, and there was gradual shrinkage and disappearance of the lesion on day 30, suggesting a clearance mechanism. We explored the possibility of lymphangiogenesis causing this clearance as part of the post-injury response. Notably, expression of lymphangiogenesis markers LYVE-1, CD34, and PROX1 was detected in damaged mouse brain tissue but not in normal tissue. Moreover, new lymphatic cells and colocalization of LYVE-1/CD34 and LYVE-1/PROX1 were also observed. Our findings of the formation of new lymphatic cells following pTBI provide preliminary insights into a post-injury clearance mechanism in the brain. Although we showed that lymphatic cells are implicated in brain tissue repair, further research is required to clarify the origin of these cells.

Ischemia with non-obstructive coronary arteries (INOCA) is an increasingly recognized disease, with a prevalence of 3 to 4 million individuals, and is associated with a higher risk of morbidity, mortality, and a worse quality of life. Persistent angina in many patients with INOCA is due to coronary microvascular dysfunction (CMD), which can be difficult to diagnose and treat. A coronary flow reserve <2.5 is used to diagnose endothelial-independent CMD. Antianginal treatments are often ineffective in endothelial-independent CMD and thus novel treatment modalities are currently being studied for safety and efficacy. CD34 + cell therapy is a promising treatment option for these patients, as it has been shown to promote vascular repair and enhance angiogenesis in the microvasculature. The resulting restoration of the microcirculation improves myocardial tissue perfusion, resulting in the recovery of coronary microvascular function, as evidenced by an improvement in coronary flow reserve. A pilot study in INOCA patients with endothelial-independent CMD and persistent angina, treated with autologous intracoronary CD34 + stem cells, demonstrated a significant improvement in coronary flow reserve, angina frequency, Canadian Cardiovascular Society class, and quality of life (ESCaPE-CMD, NCT03508609). This work is being further evaluated in the ongoing FREEDOM (NCT04614467) placebo-controlled trial.

Human cytomegalovirus (HCMV) microRNAs play essential roles in latency and reactivation in CD34 + hematopoietic progenitor cells (HPCs) via regulation of viral and cellular gene expression. In the present study, we show that HCMV miR-US25-1 targets RhoA, a small GTPase required for CD34 + HPC self-renewal, proliferation, and hematopoiesis. Expression of miR-US25-1 impairs signaling through the nonmuscle myosin II light chain, which leads to a block in cytokinesis and an inhibition of proliferation. Moreover, infection with an HCMV mutant lacking miR-US25-1 resulted in increased proliferation of CD34 + HPCs and a decrease in the proportion of genome-containing cells at the end of latency culture. These observations provide a mechanism by which HCMV limits proliferation to maintain latent viral genomes in CD34 + HPCs. IMPORTANCE Each herpesvirus family establishes latency in a unique cell type. Since herpesvirus genomes are maintained as episomes, the virus needs to devise mechanisms to retain the latent genome during cell division. Alphaherpesviruses overcome this obstacle by infecting nondividing neurons, while gammaherpesviruses tether their genome to the host chromosome in dividing B cells. The betaherpesvirus human cytomegalovirus (HCMV) establishes latency in CD34 + hematopoietic progenitor cells (HPCs), but the mechanism used to maintain the viral genome is unknown. In this report, we demonstrate that HCMV miR-US25-1 downregulates expression of RhoA, a key cell cycle regulator, which results in inhibition of CD34 + HPC proliferation by blocking mitosis. Mutation of miR-US25-1 during viral infection results in enhanced cellular proliferation and a decreased frequency of genome-containing CD34 + HPCs. These results reveal a novel mechanism through which HCMV is able to regulate cell division to prevent viral genome loss during proliferation., (Copyright © 2021 Diggins et al.)

Background: Lymphovascular invasion (LVI) is believed to be the mechanism by which melanoma cells can disseminate to regional lymph nodes and distant sites and may be predictive of adverse outcome. Lymphovascular invasion often difficult to detect on hematoxylin-eosin (HE) stained sections, are readily identified with dual immunohistochemistry (IHC) for melanocytic and vascular markers., Methods: A total of 100 primary cutaneous malignant melanoma cases that had a Breslow thickness of 1-4 mm and lacked LVI by conventional HE assessment were included. We compared the LVI detection rates of double staining for CD31/S100 and CD34/S100, and D2-40/S100, and examined the association of LVI with clinical outcomes., Results: The dual immunohistochemical positivity for CD31/S100, CD34/S100, and D2-40/S100 were 40(40%), 17(17%) and 35(35%), respectively. On multivariate analysis, LVI was an independent predictor of SLN status. Multivariate analysis revealed that LVI and male gender were independent risk factors for overall survival., Conclusions: The recognition of LVI is improved by dual IHC and predicts SLN metastasis. The detection of LVI using dual IHC, especially by a combination of CD31/S100 and D2-40/S100 is a useful step that inclusion should be recommended in basic evaluation parameters for cutaneous melanoma., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Accumulation in target cells is an essential pharmacokinetic step of targeted therapies. Tyrosine Kinase Inhibitors (TKI) against the BCR-ABL fusion protein in Chronic Phase-Chronic Myeloid Leukaemia (CP-CML) cells constitute a unique model in terms of efficacy, specificity, and in vivo demonstration of response heterogeneity by target cells. The overall therapeutic response to nilotinib is heterogeneous with no satisfactory explanation. To better understand the patients' response heterogeneity, we quantified nilotinib uptake by primary CP-CML cells in standardized conditions using flow cytometry, which allowed also distinguishing mature (polymorphonuclear cells) from immature (CD34 + ) cells. Nilotinib was undetectable in 13.3% of PMN and 40% of CD34 +  cells. Moreover, in CD34 + cells, intracellular nilotinib did not completely abolish BCR-ABL activity (monitored by CrkL phosphorylation inhibition), although nilotinib accumulated well in most CD34 + cell samples. Intracellular nilotinib concentration was inversely correlated with disease burden parameters, Sokal score, and early haematologic response at day 6 ± 1 only in PMN, suggesting an intrinsic ability to limit nilotinib entry in the forms with higher tumor cell burdenat diagnosis. These findings suggest that nilotinib accumulation in CP-CML cells is influenced by individual characteristics and intra-clonal heterogeneity, and might be used for pharmacokinetic studies and to assess the therapeutic response.

Hematopoietic stem/progenitor cells (HSPCs) participate in cardiovascular (CV) homeostasis and generate different types of blood cells including lymphoid and myeloid cells. Diabetes mellitus (DM) is characterized by chronic increase of pro-inflammatory mediators, which play an important role in the development of CV disease, and increased susceptibility to infections. Here, we aimed to evaluate the impact of DM on the transcriptional profile of HSPCs derived from bone marrow (BM). Total RNA of BM-derived CD34 + stem cells purified from sternal biopsies of patients undergoing coronary bypass surgery with or without DM (CAD and CAD-DM patients) was sequenced. The results evidenced 10566 expressed genes whose 79% were protein-coding genes, and 21% non-coding RNA. We identified 139 differentially expressed genes ( p -value < 0.05 and |log2 FC| > 0.5) between the two comparing groups of CAD and CAD-DM patients. Gene Set Enrichment Analysis (GSEA), based on Gene Ontology biological processes (GO-BP) terms, led to the identification of fourteen overrepresented biological categories in CAD-DM samples. Most of the biological processes were related to lymphocyte activation, chemotaxis, peptidase activity, and innate immune response. Specifically, HSPCs from CAD-DM patients displayed reduced expression of genes coding for proteins regulating antibacterial and antivirus host defense as well as macrophage differentiation and lymphocyte emigration, proliferation, and differentiation. However, within the same biological processes, a consistent number of inflammatory genes coding for chemokines and cytokines were up-regulated. Our findings suggest that DM induces transcriptional alterations in HSPCs, which are potentially responsible of progeny dysfunction.

Human cytomegalovirus (HCMV) infection of myeloid lineage cells, such as CD34 + hematopoietic progenitor cells (HPCs) or monocytes, results in the upregulation of antiapoptotic cellular proteins that protect the newly infected cells from programmed cell death. The mechanisms used by HCMV to regulate proapoptotic cellular proteins upon infection of CD34 + HPCs have not been fully explored. Here, we show that HCMV utilizes pUL7, a secreted protein that signals through the FLT3 receptor, and miR-US5-1 and miR-UL112-3p to reduce the abundance and activity of the proapoptotic transcription factor FOXO3a at early times after infection of CD34 + HPCs. Regulation of FOXO3a by pUL7, miR-US5-1, and miR-UL112 results in reduced expression of the proapoptotic BCL2L11 transcript and protection of CD34 + HPCs from virus-induced apoptosis. These data highlight the importance of both viral proteins and microRNAs (miRNAs) in protecting CD34 + HPCs from apoptosis at early times postinfection, allowing for the establishment of latency and maintenance of viral genome-containing cells. IMPORTANCE Human cytomegalovirus (HCMV) causes serious disease in immunocompromised individuals and is a significant problem during transplantation. The virus can establish a latent infection in CD34 + hematopoietic progenitor cells (HPCs) and periodically reactivate to cause disease in the absence of an intact immune system. What viral gene products are required for successful establishment of latency is still not fully understood. Here, we show that both a viral protein and viral miRNAs are required to prevent apoptosis after infection of CD34 + HPCs. HCMV pUL7 and miRNAs miR-US5-1 and miR-UL112-3p act to limit the expression and activation of the transcription factor FOXO3a, which in turn reduces expression of proapoptotic gene BCL2L11 and prevents virus-induced apoptosis in CD34 + HPCs., (Copyright © 2021 Hancock et al.)

Mice with human hematopoietic system have become critical for research and preclinical studies. Mice with patient-derived xenografts of different tumors exist without human immune system. Answers can be addressed with the same immunodeficient mice that are chimeric for the human hemato-lymphoid system (humanized mice). The growing field of immune-oncology could benefit from preclinical studies with the humanized mice. Other fields will also benefit such as studies of infectious disease, regenerative medicine, organ transplant, and allergies. Here, we describe the method to humanize immune-deficient mice with human CD34 + hematopoietic cells.

The ability of immobilized conjugate anti-CD34 + monoclonal antibody-dR110 and free conjugate anti-CD45 + monoclonal antibody-ATTO620 to precisely enumerate CD34 + stem cells and CD45 + cells in apheresis samples were evaluated. The conjugates anti-CD34 + antibody-dR110 and anti-CD45 + - antibody-ATTO620 were prepared. Functionalized magnetic nanoparticles (MNPs) were synthesized. The anti-CD34 + antibody-dR110 conjugate was immobilized on the modified MNPs using a carbodiimide method. The stem cell count in thawed apheresis samples was determined using the free and the immobilized conjugate anti-CD34 + antibody-dR110 on MNPs and an image cell counter EasyCounter BC. A higher stem cell count and more accurate results were obtained with the immobilized conjugate, because a separation and concentration of the stem cells bound to antibody-dR110 on MNPs by external magnet were performed. Coefficients of variation of CD34 + cell count in apheresis samples, determined by EasyCounter BC, were ranged from 5.5 to 6.9% and those of CD45 + cell count from 3.8 to 4.7%. The viability of CD34 + cells was high from 98.5 to 99.6%. It was found that correlation coefficient between the flow cytometer and automatic cell counter, using free anti-CD34 + antibody-dR110 was 0.94, and when using immobilized anti-CD34 + antibody-dR110 on MNPs, the correlation coefficient was 0.97., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: To compare mast cell and microvessel densities among histologic grades of oral squamous cell carcinoma., Setting: Armed Forces Institute of Pathology., Materials and Methods: A total of 60 specimens of OSCC comprising 20 each of well, moderately and poorly differentiated were evaluated. Immunohistochemical analysis was performed to measure MCD and MVD by applying monoclonal CD117 antibody and monoclonal CD34 antibody, on formalin fixed and paraffin embedded sections. ANOVA and Post Hoc Tukey test was employed to assess the densities and to compare the differences between different grades of OSCC. A p-value.

Background: Sarcoidosis is a multisystemic granulomatous disease with still unknown etiology. Our previous studies showed a significantly higher percentage of CD34 + cells in the peripheral blood in patients with sarcoidosis (SA) compared to the control group. The objective of the present study was to characterized of the CD34 + cell population in peripheral blood in patients with SA with reference to the control group. Moreover in patients with SA, fibrocytes and endothelial cells were analysed and their relationship to the fibrosis process based on assessment of diffusing capacity for carbon monoxide (DLCO)., Methods: Data from patients diagnosed with SA at Military Institute of Medicine (Warsaw, Poland) between January 2018 and December 2019 were collected and analysed ongoing basis. Peripheral blood was collected from 26 patients with newly diagnosed pulmonary SA and 16 healthy subjects. The immunomagnetic method and flow cytometry were used. Among the CD34+ progenitor cells were assessed: low-differentiated cells, hematopoietic progenitor cells and endothelial progenitor cells. The Statistica 12.0 software was used for a statistical analysis., Results: We observed a significantly higher percentage of low-differentiated cells (13.8 vs. 2.3, P = 0.001) and endothelial cells (0.3 vs. 0.0, P = 0.001) in patients with SA compared to the control group. In the study group the median proportion of fibrocytes was 1.877% (0.983-2.340) in patients with DLCO< 80%, while in patients with DLCO> 80% was 0.795% (0.139-1.951) (P = 0.72). The median proportion of endothelial progenitor cells was higher in patients with DLCO< 80%: 0.889% (0.391-1.741), than in patients with DLCO> 80%: 0.451% (0.177-0.857) (P = 0.44)., Conclusions: In conclusion we demonstrated for the first time the immunophenotype of peripheral CD34 + cells with the degree of their differentiation. The study confirmed the involvement of low differentiated cells and endothelial cells in patients with SA.

Lung innate immune activation results in acute lung inflammation, which is characterized by alveolar barrier disruption and accumulation of cellular lung aggregates comprising neutrophils, platelets, mononuclear cells, and microparticles. CD34 is a sialomucin, with pan-selectin affinity and recently shown to protect the endothelial barrier in a bleomycin-induced lung injury model. However, there is very little information about the fundamental role of CD34 in regulation of the lung innate immune response. We hypothesized that CD34 regulates leukocyte recruitment by promoting optimal platelet activation (aggregation and spread) during bacterial lipopolysaccharide (LPS)-induced acute lung injury. Therefore, we utilized CD34 knock-out (KO) and wild-type (WT) mice to analyze and compare the morphology and expression of leukocyte subsets from the pulmonary and systemic compartments. We utilized the chemotactic N-formylated tri-peptide, fMLP, to understand platelet aggregation in vitro, and the fundamental immune stimulant, LPS, to induce lung injury and understand platelet activation ex vivo. Our data reveal that under steady-state conditions, KO mice possess large aggregates of integrin β 3 (CD61)-positive microparticles in peripheral blood. Moreover, the KO mice recruit a large number of neutrophils to lungs, which are not cleared even at 36-h post-LPS exposure. The KO mice display an increased platelet CD61 expression, which aggregates, but does not spread normally in response to in vitro fMLP treatment. The KO platelets display similar deficits in their spreading ability even after ex vivo LPS exposure. Thus, our data demonstrate that CD34 modulates platelet biology, microparticle aggregation, and neutrophil recruitment during murine lung inflammation.

Myelotoxicity is a serious side effect of anticancer drugs. The search for drugs that can reduce the hematological complications of chemotherapy through modulation of hematopoietic stem cells is an urgent task of oncopharmacology. In the present study we showed that administration of Tussilago farfara L. polysaccharides to C57BL/6 mice treated with cyclophosphamide can increase the number of hematopoietic stem cells (CD117 + 34 + ) in the bone marrow.

Backgrounds: The association of neutrophil-lymphocyte ratio (NLR) and CD34 expression level with PSA level, Gleason score, and clinical stage was investigated in patients with prostate cancer. The correlation between NLR and CD34 expression was also investigated to provide evidence supporting the use of NLR for predicting the prognosis of prostate cancer patients., Methods: Clinical data of 75 patients diagnosed with prostate cancer by prostate aspiration biopsy were retrospectively analyzed. The correlation between NLR, CD34 expression, and clinicopathological characteristics was analyzed using the χ2 test and one-way analysis of variance. The correlation between NLR and CD34 was determined using the Pearson coefficient. Disease free survival was estimated by Kaplan-Meier analysis., Results: Both NLR and CD34 expression were significantly positively correlated with PSA, Gleason score, and clinical stage (P < 0.05 both). Patients in the NLR High /CD34 High group were characterized by high PSA level and Gleason score and late clinical stage. NLR was positively correlated with CD34 expression (r = 0.529, P < 0.001)., Conclusions: Pretreatment NLR was a valuable marker of prognosis in prostate cancer. NLR is positively correlated with CD34 expression.

Differentiation of the HSCs into myeloid lineage is primarily monitored by transcription factor PU.1. GATA1 acts as a negative regulator by antagonizing the function of PU.1 by bindings its β3/β4 domain. In this study, a mutation was induced in PU.1 which blocks its interaction with GATA1. The pure form of this mutant protein i.e Y244D was loaded on poly (lactic-co-glycolic acid) nanoparticles to transfect CD34 + cells, which act as a selective tool to enhance the myelopoiesis, as confirmed by flow cytometry analysis. Further, microarray data analysis was performed to gather information on myelopoiesis specific signaling pathways and genes involved in myelopoiesis like CCL2, S100A8, and S100A9, which were also found to be significantly upregulated in the mutant form. Different molecular functions like antioxidant activity, signal transduction, developmental processes, and biological adhesion were analyzed. This study potentially signifies that PU.1 mutant is highly efficient in myelopoiesis., (Copyright © 2020. Published by Elsevier B.V.)

Single cell RNA sequencing of human thymic cells is dependent on isolation of highly pure and viable cell populations. This protocol describes the isolation of CD34 + progenitor and more differentiated CD34 - fractions from post-natal thymic tissue to study thymopoiesis. CD34 + cells represent <1% of thymic cells, so this protocol uses magnetic- followed by fluorescence-activated cell separation to isolate highly enriched CD34 + cells. For complete details on the use and execution of this protocol, please refer to Le et al. (2020)., Competing Interests: The authors declare no competing interests., (© 2020 The Authors.)

Magnesium alloy is generally accepted as a potential cardiovascular stent material due to its good mechanical properties, biocompatibility, and biodegradability, and has become one of the research hotspots in this field. However, too fast degradation rate and delayed surface endothelialization have been the bottleneck of further application of magnesium alloy stent. In this study, we selected Mg-Zn-Y-Nd, a kind of biodegradable magnesium alloy for cardiovascular stent, and passivated its surface by alkali heat treatment and silane treatment to improve the corrosion resistance, subsequently conjugated Arg-Glu-Asp-Val (REDV) peptide and anti-CD34 to promote endothelial cells adhesion and capture endothelial progenitor cells respectively, further improving surface endothelialization. In addition, the heparin was also immobilized to the Mg-Zn-Y-Nd surface for the consideration of anti-coagulation and anti-inflammation. Systematic material characterization and biological evaluation show that we have successfully developed this composite surface on Mg-Zn-Y-Nd alloy, and achieved multiple functions such as corrosion resistance, promoting endothelialization, and inhibiting platelet/macrophage adhesion.

Angiogenesis is important for the proliferation and survival of multiple myeloma (MM) cells. Bone marrow (BM) microvessel density (MVD) is a useful marker of angiogenesis and an increase in MVD can be used as a marker of poor prognosis in MM patients. We developed an automated image analyzer to assess MVD from images of BM biopsies stained with anti-CD34 antibodies using two color models. MVD was calculated by merging images from the red and hue channels after eliminating non-microvessels. The analyzer results were compared with those obtained by two experienced hematopathologists in a blinded manner using the 84 BM samples of MM patients. Manual assessment of the MVD by two hematopathologists yielded mean±SD values of 19.4±11.8 and 20.0±11.8. The analyzer generated a mean±SD of 19.5±11.2. The intraclass correlation coefficient (ICC) and Bland-Altman plot of the MVD results demonstrated very good agreement between the automated image analyzer and both hematopathologists (ICC=0.893 [0.840-0.929] and ICC=0.906 [0.859-0.938]). This automated analyzer can provide time- and labor-saving benefits with more objective results in hematology laboratories., Competing Interests: No potential conflicts of interest relevant to this article are reported., (© The Korean Society for Laboratory Medicine.)

The clinical success of immune checkpoint modulators and the development of next-generation immune-oncology (IO) agents underscore the need for robust preclinical models to evaluate novel IO therapeutics. Human immune system (HIS) mouse models enable in vivo studies in the context of the HIS via a human tumor. The immunodeficient mouse strains NOG (Prkdc scid Il2rg tm1Sug ) and triple-transgenic NOG-EXL [Prkdc scid Il2rg tm1Sug Tg (SV40/HTLV-IL3, CSF2)], which expresses human IL-3 and GM-CSF, allow for human CD34+ hematopoietic stem cell (huCD34+ HSC) engraftment and multilineage immune cell development by 12 to 16 weeks post-transplant and facilitate studies of immunomodulatory agents. A more rapid model of human immune engraftment utilizes peripheral blood mononuclear cells (PBMCs) transplanted into immunodeficient murine hosts, permitting T-cell engraftment within 2 to 3 weeks without outgrowth of other human immune cells. The PBMC-HIS model can be limited due to onset of xenogeneic graft-versus-host disease (xGVHD) within 3 to 5 weeks post-implantation. Host deficiency in MHC class I, as occurs in beta-2 microglobulin knockout in either NOG or NSG mice, results in resistance to xGVHD, which permits a longer therapeutic window. In this article, detailed processes for generating humanized mice by transplantation of HSCs from cord blood-derived huCD34+ HSCs or PBMCs into immunodeficient mouse strains to respectively generate HSC-HIS and PBMC-HIS mouse models are provided. In addition, the co-engraftment and growth kinetics of patient-derived and cell line-derived xenograft tumors in humanized mice and recovery of tumor-infiltrating lymphocytes from growing tumors to evaluate immune cell subsets by flow cytometry are described. © 2020 The Authors. Basic Protocol 1: Establishment of patient-derived xenograft tumors in CD34+ hematopoietic stem cell-humanized mice Basic Protocol 2: Establishment of patient-derived xenograft tumors in peripheral blood mononuclear cell-humanized mice Support Protocol 1: Flow cytometry assessment of humanization in mice Support Protocol 2: Flow cytometry assessment of tumor-infiltrating lymphocytes in tumor-bearing humanized mouse models., (© 2020 The Authors.)

Numerous cell types modulate hematopoiesis through soluble and membrane bound molecules. Whether developing hematopoietic progenitors of a particular lineage modulate the differentiation of other hematopoietic lineages is largely unknown. Here we aimed to investigate the influence of myeloid progenitors on CD34 + cell differentiation into CD56 + innate lymphocytes. Sorted CD34 + cells cultured in the presence of stem cell factor (SCF) and FMS-like tyrosine kinase 3 ligand (FLT3L) give rise to numerous cell types, including progenitors that expressed the prolactin receptor (PRLR). These CD34 + PRLR + myeloid-lineage progenitors were derived from granulocyte monocyte precursors (GMPs) and could develop into granulocytes in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) in vitro. Moreover, CD34 + PRLR + myeloid progenitors lacked lymphoid developmental potential, but when stimulated with prolactin (PRL) they increased the differentiation of other CD34 + cell populations into the NK lineage in a non-contact dependent manner. Both mRNA and protein analyses show that PRL increased mothers against decapentaplegic homolog 7 (SMAD7) in CD34 + PRLR + myeloid cells, which reduced the production of transforming growth factor beta 1 (TGF-β1), a cytokine known to inhibit CD56 + cell development. Thus, we uncover an axis whereby CD34 + PRLR + GMPs inhibit CD56 + lineage development through TGF-β1 production and PRL stimulation leads to SMAD7 activation, repression of TGF-β1, resulting in CD56 + cell development.

Background: Coronary stent neoatherosclerosis, thrombosis, and restenosis remain significant concerns with new-generation drug-eluting stents (DES). The Dual-Therapy CD34 antibody-covered sirolimus-eluting stent [dual therapy stent (DTS)] is a sirolimus-eluting stent with CD34 antibodies immobilized on its luminal surface to capture circulating endothelial progenitor cells and promote early endothelialization. We conducted a meta-analysis to determine whether the DTS was superior to standard DES., Methods: We conducted a comprehensive search for controlled randomized and non-randomized studies. We presented data using risk ratios (95% confidence intervals) and measured heterogeneity using Higgins' I 2 ., Results: Five studies with a low risk of bias met the inclusion criteria, with a total of 1884 patients in the DTS and 1819 in standard DES arms. There was no difference between the 2 arms in the following 1-year outcomes: cardiac death [1% vs 0.9% RR 1.13 (95% CI 0.49-2.62) I 2  = 0%], target lesion failure [6.2% vs 5.3% RR 1.12 (0.80-1.58) I 2  = 0%], target lesion revascularization (TLR) [4.9% vs 3.4% RR 1.40 (0.93-2.10) I 2  = 15%], target vessel failure [8.2% vs 6.1% RR 1.24 (0.75-2.04) I 2  = 0%], target vessel myocardial infarction [1.1% vs 1.8% RR 0.73 (0.19-2.90) I 2  = 62%] and stent thrombosis [0.4% vs 0.6% HR 0.85 (0.27-2.62) I 2  = 0%]. However, compared with second-generation DES (EES and ZES), the DTS had significantly higher one-year TLR [5% vs. 3.1% RR 1.58 (1.02-2.46) P = 0.04 I 2  = 0%]., Conclusion: One-year TLR was significantly higher in the DTS arm compared with second-generation DES. There was no difference in the other 1-year clinical outcomes compared with standard DES., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Besides monocyte (MO)-derived macrophages (MACs), self-renewing tissue-resident macrophages (trMACs) maintain the intracutaneous MAC pool in murine skin. Here, we have asked whether the same phenomenon occurs in human skin using organ-cultured, full-thickness skin detached from blood circulation and bone marrow. Skin stimulation ex vivo with the neuropeptide substance P (SP), mimicking neurogenic skin inflammation, significantly increased the number of CD68+MACs in the papillary dermis without altering intracutaneous MAC proliferation or apoptosis. Since intraluminal CD14+MOs were undetectable in the non-perfused dermal vasculature, new MACs must have differentiated from resident intracutaneous progenitor cells in human skin. Interestingly, CD68+MACs were often seen in direct cell-cell-contact with cells expressing both, the hematopoietic stem cell marker CD34 and SP receptor (neurokinin-1 receptor [NK1R]). These cell-cell contacts and CD34+cell proliferation were up-regulated in SP-treated skin samples. Collectively, our study provides the first evidence that resident MAC progenitors, from which mature MACs can rapidly differentiate within the tissue, do exist in normal adult human skin. That these NK1R+trMAC-progenitor cells quickly respond to a key stress-associated neuroinflammatory stimulus suggests that this may satisfy increased local MAC demand under conditions of wounding/stress., Competing Interests: The authors have read the journal's policy and the authors of this manuscript have the following competing interest: MB and JC are or were employed of Monasterium Laboratory GmbH. JG is a paid employee of Monasterium Laboratory GmbH, Münster. RP is the founder and CEO of Monasterium laboratory. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Background: Aberrant phenotypes in acute leukemia have been reported with varying frequencies in independent studies and their association with prognostic factors is still a matter of debate., Aim: This study aims to identify the frequency of aberrant immunophenotypes in de novo acute myeloid leukemia (AML) and to evaluate their association with initial clinical and hematological features., Materials and Methods: A total of 181 patients of de novo AML were included during the time (July 2010-June 2012). The immunophenotype of all cases of AML was studied by using flow cytometry., Results: Aberrant lymphoid antigen expression was seen in 43.1% cases. Most frequent aberrant lymphoid antigen was CD7, seen in 26.5% cases. All French-American-British (FAB) subtypes except AML-M3 expressed aberrant lymphoid antigens. The expression was most common in AML-M4 in the current study. CD34 expression in AMLs was significantly associated with the expression of aberrant lymphoid antigens. Lymphoid antigen expression in adult AML was significantly associated with higher white blood cell (WBC) count (>50,000/mm 3 ) and higher number of peripheral blasts (>70%)., Conclusion: In summary, CD7 is the most common aberrant lymphoid antigen expressed in AML. FAB subtype AML-M3 is usually not associated with aberrant lymphoid antigen expression. AML cases with CD34 positivity are more likely to express aberrant lymphoid markers. The current study also supports that aberrant lymphoid antigen expression in adult AML is associated with adverse presenting hematological features (WBC count >50,000/mm 3 , peripheral blasts >70%). Pediatric Ly + AML cases are not associated with adverse presenting clinical and biological features., Competing Interests: None

CD34 + hematopoietic stem/progenitor cells (HSPCs) are vasculogenic and hypoxia is a strong stimulus for the vasoreparative functions of these cells. Angiotensin-converting enzyme 2 (ACE2)/angiotensin-(1-7)/Mas receptor (MasR) pathway stimulates vasoprotective functions of CD34 + cells. This study tested if ACE2 and MasR are involved in the hypoxic stimulation of CD34 + cells. Cells were isolated from circulating mononuclear cells derived from healthy subjects (n = 46) and were exposed to normoxia (20% O 2 ) or hypoxia (1% O 2 ). Luciferase reporter assays were carried out in cells transduced with lentivirus carrying ACE2- or MasR- or a scramble-3'-untranslated region gene with a firefly luciferase reporter. Expressions or activities of ACE, angiotensin receptor Type 1 (AT1R), ACE2, and MasR were determined. In vitro observations were verified in HSPCs derived from mice undergoing hindlimb ischemia (HLI). In vitro exposure to hypoxia-increased proliferation and migration of CD34 + cells in basal conditions or in response to vascular endothelial growth factor (VEGF) or stromal-derived factor 1α (SDF) compared with normoxia. Expression of ACE2 or MasR was increased relative to normoxia while ACE or AT1R expressions were unaltered. Luciferase activity was increased by hypoxia in cells transfected with the luciferase reporter plasmids coding for the ACE2- or MasR promoters relatively to the control. The effects of hypoxia were mimicked by VEGF or SDF under normoxia. Hypoxia-induced ADAM17-dependent shedding of functional ACE2 fragments. In mice undergoing HLI, increased expression/activity of ACE2 and MasR were observed in the circulating HSPCs. This study provides compelling evidence for the hypoxic upregulation of ACE2 and MasR in CD34 + cells, which likely contributes to vascular repair., (© 2019 Wiley Periodicals, Inc.)

Retinopathy of prematurity (ROP) is a disorder of the developing retina of preterm infants. ROP can lead to blindness because of abnormal angiogenesis that is the result of suspended vascular development and vaso-obliteration leading to severe retinal stress and hypoxia. We tested the hypothesis that the use of the human progenitor cell combination, bone marrow-derived CD34+ cells and vascular wall-derived endothelial colony-forming cells (ECFCs), would synergistically protect the developing retinal vasculature in a mouse model of ROP, called oxygen-induced retinopathy (OIR). CD34+ cells alone, ECFCs alone, or the combination thereof were injected intravitreally at either P5 or P12 and pups were euthanized at P17. Retinas from OIR mice injected with ECFCs or the combined treatment revealed formation of the deep vascular plexus (DVP) while still in hyperoxia, with normal-appearing connections between the superficial vascular plexus (SVP) and the DVP. In addition, the combination of cells completely prevented aberrant retinal neovascularization and was more effective anatomically and functionally at rescuing the ischemia phenotype than either cell type alone. We show that the beneficial effects of the cell combination are the result of their ability to orchestrate an acceleration of vascular development and more rapid ensheathment of pericytes on the developing vessels. Lastly, our proteomic and transcriptomic data sets reveal pathways altered by the dual cell therapy, including many involved in neuroretinal maintenance, and principal component analysis (PCA) showed that cell therapy restored OIR retinas to a state that was closely associated with age-matched normal retinas. Together, these data herein support the use of dual cell therapy as a promising preventive treatment for the development of ROP in premature infants.

Recent marketing approval for genetically engineered hematopoietic stem and T cells bears witness to the substantial improvements in lentiviral vectors over the last two decades, but evaluations of the long-term efficacy and toxicity of gene and cell therapy products will, nevertheless, require further studies in nonhuman primate models. Macaca fascicularis monkeys from Mauritius have a low genetic diversity and are particularly useful for reproducible drug testing. In particular, they have a genetically homogeneous class I major histocompatibility complex system that probably mitigates the variability of the response to simian immunodeficiency virus infection. However, the transduction of simian cells with human immunodeficiency virus type 1 (HIV-1)-derived vectors is inefficient due to capsid-specific restriction factors, such as the tripartite motif-containing protein tripartite motif 5α, which prevent infection with non-host-adapted retroviruses. This study introduced the modified capsid of the macaque-trophic HIV-1 clone MN4/LSQD into the packaging system and compared transduction efficiencies between hematopoietic cells transduced with this construct and cells transduced with HIV-1 NL4-3-derived packaging constructs. Capsid modification increased transduction efficiency in all hematopoietic cells tested (by factors of up to 10), including hematopoietic progenitor cells, repopulating cells, and T cells from Mauritian Macaca fascicularis , regardless of vector structure or purification method. The study also established culture conditions similar to those used in clinical practice for the efficient transduction of hematopoietic stem and progenitor CD34 + cells. These results suggest that the procedure is suitable for use in Mauritian Macaca fascicularis , which can therefore be used as a model in preclinical studies for hematopoietic gene and cell therapy.

To confirm that neoplastic monocyte-derived collagen- and fibronectin-producing fibrocytes induce bone marrow (BM) fibrosis in primary myelofibrosis (PMF), we injected PMF BM-derived fibrocyte-precursor CD14+/CD34- monocytes into the tail vein of NOD-SCID-γ (NSG) mice. PMF BM-derived CD14+/CD34- monocytes engrafted and induced a PMF-like phenotype with splenomegaly, myeloid hyperplasia with clusters of atypical megakaryocytes, persistence of the JAK2V617F mutation, and BM and spleen fibrosis. As control we used normal human BM-derived CD14+/CD34- monocytes. These monocytes also engrafted and gave rise to normal megakaryocytes that, like PMF CD14+/CD34--derived megakaryocytes, expressed HLA-ABC and human CD42b antigens. Using 2 clonogenic assays we confirmed that PMF and normal BM-derived CD14+/CD34- monocytes give rise to megakaryocyte colony-forming cells, suggesting that a subpopulation BM monocytes harbors megakaryocyte progenitor capacity. Taken together, our data suggest that PMF monocytes induce myelofibrosis-like phenotype in immunodeficient mice and that PMF and normal BM-derived CD14+/CD34- monocytes give rise to megakaryocyte progenitor cells., Competing Interests: The authors have declared that no competing interests exist.