Ferroptosis contributes to airway epithelial E-cadherin disruption in a mixed granulocytic asthma mouse model

Aberrant expression of airway epithelial E-cadherin is a key feature of asthma, yet the underlying mechanisms are largely unknown. Ferroptosis is a novel form of regulated cell death involved in asthma pathogenesis. This study was aimed to evaluate the role of ferroptosis and to investigate whether ferroptosis mediates E-cadherin disruption in mixed granulocyte asthma (MGA). Two murine models of MGA were established using toluene diisocyanate (TDI) or ovalbumin with Complete Freund's Adjuvant (OVA/CFA). Specific antagonists of ferroptosis, including Liproxstatin-1 (Lip-1) and Ferrostatin-1 (Fer-1) were given to the mice. The allergen-exposed mice displayed markedly shrunk mitochondria in the airway epithelia, with decreased volume and denser staining accompanied by down-regulated GPX4 as well as up-regulated FTH1 and malondialdehyde, which are markers of ferroptosis. Decreased pulmonary expression of E-cadherin was also observed, with profound loss of membrane E-cadherin in the airway epithelia, as well as increased secretion of sE-cadherin. Treatment with Lip-1 not only showed potent protective effects against the allergen-induced airway hyperresponsiveness and inflammatory responses, but also rescued airway epithelial E-cadherin expression and inhibited the release of sE-cadherin. Taken together, our data demonstrated that ferroptosis mediates airway epithelial E-cadherin dysfunction in MGA.

New insights into the treatment of polycystic ovary syndrome: HKDC1 promotes the growth of ovarian granulocyte cells by regulating mitochondrial function and glycolysis

Polycystic ovary syndrome (PCOS) is an endocrine disease, and its pathogenesis and treatment are still unclear. Hexokinase domain component 1 (HKDC1) participates in regulating mitochondrial function and glycolysis. However, its role in PCOS development remains unrevealed. Here, female C57BL/6 mice were intraperitoneally injected with dehydroepiandrosterone (DHEA; 60 mg/kg body weight) to establish an in vivo model of PCOS. In vitro, KGN cells, a human ovarian granular cell line, were used to explore the potential mechanisms. DHEA-treated mice exhibited a disrupted estrus cycle, abnormal hormone levels, and insulin resistance. Dysfunction in mitochondria and glycolysis is the main reason for PCOS-related growth inhibition of ovarian granular cells. Here, we found that the structure of mitochondria was impaired, less ATP was generated and more mitochondrial Reactive Oxygen Species were produced in HKDC1-silenced KGN cells. Moreover, HKDC1 knockdown inhibited glucose consumption and decreased the production of glucose-6-phosphate and lactic acid. Conclusively, HKDC1 protects ovarian granulocyte cells from DHEA-related damage at least partly by preserving mitochondrial function and maintaining glycolysis.

[Possible Risk Factors for Bone Marrow Fibroplasia in Patients with Polycythemia Vera]

OBJECTIVE

To understand the biological characteristics of polycythemia vera (PV) patients with myeloid fibroplasia, and further analyze the risk factors affecting myeloid fibroplasia in PV patients, so as to provide ideas for predicting the occurrence of myeloid fibroplasia in PV patients.

METHODS

Forty patients with PV in the Department of Hematology, Xiyuan Hospital of China Academy of Chinese Medical Sciences were collected and divided into two groups, with (hyperplasia group) and without (Non-proliferative group) hyperplasia of bone marrow fibers. The differences of basic clinical characteristics, blood routine, biochemistry, bone marrow cells, coagulation function and other indicators between the two groups were compared, and the independent risk factors affecting the proliferation of bone marrow fibrous tissue in PV patients were further analyzed by multivariate regression.

RESULTS

Compared with Non-proliferative group, the JAK2 mutation rate (95% vs 70%，P=0.037), eosinophilic cell count (0.19 vs 0.11, P=0.047) and eosinophilic percentage (1.84 vs 1.27, P=0.001) in PV patients with hyperplasia were significantly increased, triglycerides (1.55 vs 1.91, P=0.038) and low-density lipoprotein (1.50 vs 3.08, P=0.000) were significantly reduced, bone marrow hematopoietic volume (0.85 vs 0.6, P=0.001), granulocyte/erythrocyte ratio (3.40 vs 1.89, P=0.033), lymphocyte/erythrocyte ratio (0.60 vs 0.42, P=0.033), and granulocyte+lymphocyte/erythrocyte ratio (3.72 vs 2.37, P=0.026) were significantly increased, thrombin time (18.84 vs 18.12, P=0.043) was significantly prolonged. Multivariate regression analysis results showed that peripheral blood eosinophil ≥2% and low-density lipoprotein ≤2 mmol/L were independent risk factors for bone marrow fibrous tissue hyperplasia in PV patients (P<0.05).

CONCLUSION

Increased proportion of peripheral blood eosinophils and decreased low density lipoprotein are risk factors for bone marrow fibrous tissue hyperplasia in PV patients.

Adenosquamous carcinoma of the gallbladder simultaneously producing granulocyte-colony-stimulating factor and parathyroid hormone-related protein

We report a rare case of adenosquamous carcinoma of the gallbladder which simultaneously produces granulocyte-colony-stimulating factor (G-CSF) and parathyroid hormone-related protein (PTHrP), confirmed serologically and histologically. A 71-year-old man was examined for a gallbladder tumor with multiple lymph nodes and liver metastases. Histopathological evaluation by endoscopic ultrasound fine-needle aspiration revealed adenosquamous carcinoma of the gallbladder. Laboratory data showed markedly elevated white blood cell (WBC) count of 34,700 µL and corrected serum calcium level of 14.9 mg/dL. Serum G-CSF (191 pg/mL) and PTHrP (23.1 pmol/L) levels were high. Zoledronic acid and calcitonin were administered to treat hypercalcemia, which normalized serum calcium levels. Gemcitabine-cisplatin chemotherapy was started for cStage IVB gallbladder cancer. After chemotherapy initiation, WBCs showed a rapid downward trend; however, the patient suddenly developed acute respiratory distress syndrome; thus, chemotherapy was discontinued. Subsequently, WBC count increased again, and the patient's overall condition deteriorated. The patient died on day 27. Immunohistochemistry using autopsy specimens demonstrated patchy staining for G-CSF in the squamous cell carcinoma portion and diffuse and weak positive staining for PTHrP in the squamous cell carcinoma and poorly differentiated adenocarcinoma portions of the tumor, suggesting simultaneous G-CSF and PTHrP production by the tumor. This is the first report of a patient with gallbladder cancer with serological and histological evidence for G-CSF and PTHrP production.

A case of granulocyte-colony-stimulating factor-producing gallbladder cancer with lymph node metastasis together with a literature review

The granulocyte-colony-stimulating factor (G-CSF) glycoprotein stimulates precursor cell proliferation and differentiation in the bone marrow. Various G-CSF-producing tumors have been reported; they showed early progression and an extremely poor prognosis. Here, we report a case of G-CSF-producing gallbladder cancer with lymph node metastasis. In addition, we reviewed 30 previous case reports of G-CSF-producing gallbladder cancers to elucidate the characteristics and most appropriate treatment. During a routine visit to her local doctor for monitoring of diabetes and hypertension, a 68-year-old female was found to have an elevated white-blood-cell (WBC) count and C-reactive protein (CRP) level, and a gallbladder mass. Laboratory tests revealed a high serum G-CSF level, and imaging revealed a tumor of the gallbladder with regional lymphadenopathy. We diagnosed a G-CSF-producing gallbladder cancer and performed liver resection of segment IVa/V: regional lymph node dissection with extrahepatic bile duct resection. Pathologically, the tumor was a poorly differentiated squamous cell carcinoma. G-CSF immunostaining for tumor cells was positive. She is alive without recurrence at 16 months after surgery. If a patient exhibits a gallbladder tumor, with an elevated WBC count and CRP level but no symptoms of infection, a G-CSF-producing gallbladder cancer should be suspected; radical resection should be performed immediately after diagnosis.

Treatment-Induced Bone Marrow Enhancement at MRI in Breast Cancer Patients Receiving Granulocyte-Colony Stimulating Factor Adjunct to Chemotherapy

RATIONALE AND OBJECTIVES

Granulocyte-colony stimulating factor (G-CSF) induces the reconversion of fatty bone marrow to hematopoietic bone marrow. The bone marrow changes are detectable as signal intensity changes at MRI. The aim of this study was to evaluate sternal bone marrow enhancement following G-CSF and chemotherapy treatment in women with breast cancer.

MATERIALS AND METHODS

This retrospective study included breast cancer patients who received neoadjuvant chemotherapy with adjunct G-CSF. The signal intensity of sternal bone marrow at MRI on T1-weighted contrast-enhanced subtracted images was measured before treatment, at the end of treatment, and at 1-year follow-up. The bone marrow signal intensity (BM SI) index was calculated by dividing the signal intensity of sternal marrow by the signal intensity of the chest wall muscle. Data were collected between 2012 and 2017, with follow-up until August 2022. Mean BM SI indices were compared before and after treatment, and at 1-year follow-up. Differences in bone marrow enhancement between time points were analyzed using a one-way repeated measures ANOVA.

RESULTS

A total of 109 breast cancer patients (mean age 46.1 ± 10.4 years) were included in our study. None of the women had distal metastases at presentation. A repeated-measures ANOVA determined that mean BM SI index scores differed significantly across the three time points (F[1.62, 100.67] = 44.57, p < .001). At post hoc pairwise comparison using the Bonferroni correction BM SI index significantly increased between initial assessment and following treatment (2.15 vs 3.33, p < .001), and significantly decreased at 1-year follow-up (3.33 vs 1.45, p < .001). In a subgroup analysis, while women younger than 50 years had a significant increase in marrow enhancement after G-CSF treatment, in women aged 50 years and older, the difference was not statistically significant.

CONCLUSION

Treatment with G-CSF as an adjunct to chemotherapy can result in increased sternal bone marrow enhancement due to marrow reconversion. Radiologists should be aware of this effect in order to avoid misinterpretation as false marrow metastases.

Mild generalised pustular psoriasis patient with a heterozygous hypomorphic MPO variant successfully treated with granulocyte and monocyte adsorption apheresis

Pathogenic variants in MPO, which encodes the myeloperoxidase, were reported as causative genetic defects in several cases of generalised pustular psoriasis (GPP) in addition to patients with myeloperoxidase deficiency in 2020. However, which clinical subtypes of GPP patients have pathogenic variants in MPO remains largely undetermined, and elucidating this is clinically important. The present report outlines a mild case of GPP with a rare missense heterozygous variant, c.1810C>T p.(Arg604Cys), in MPO. Our structural analysis and functional assays to measure myeloperoxidase activity suggest that the present MPO substitution is a hypomorphic variant in MPO. Thus, the mild phenotype of the present GPP patient might be associated with an incomplete hypomorphic loss-of-function variant in MPO. Additionally, the severe intractable edematous pustules and erythema improved dramatically after five rounds of granulocyte and monocyte adsorption apheresis (GMA) therapy. This is the first report of GMA treatment for GPP associated with a pathogenic variant in MPO, as far as we know. Our findings suggest that GMA might be a useful and powerful tool for controlling GPP in patients with myeloperoxidase deficiency.

Granulocyte transfusion during cord blood transplant for relapsed, refractory AML is associated with massive CD8+ T-cell expansion, significant cytokine release syndrome and induction of disease remission

In high-risk myeloid malignancy, relapse is reduced using cord blood transplant (CBT) but remains the principal cause of treatment failure. We previously described T-cell expansion in CBT recipients receiving granulocyte transfusions. We now report the safety and tolerability of such transfusions, T-cell expansion data, immunophenotype, cytokine profiles and clinical response in children with post-transplant relapsed acute leukaemia who received T-replete, HLA-mismatched CBT and pooled granulocytes within a phase I/II trial (ClinicalTrials.Gov NCT05425043). All patients received the transfusion schedule without significant clinical toxicity. Nine of ten patients treated had detectable measurable residual disease (MRD) pre-transplant. Nine patients achieved haematological remission, and eight became MRD negative. There were five deaths: transplant complications (n = 2), disease (n = 3), including two late relapses. Five patients are alive and in remission with 12.7 months median follow up. Significant T-cell expansion occurred in nine patients with a greater median lymphocyte count than a historical cohort between days 7-13 (median 1.73 × 109 /L vs. 0.1 × 109 /L; p < 0.0001). Expanded T-cells were predominantly CD8+ and effector memory or TEMRA phenotype. They exhibited markers of activation and cytotoxicity with interferon-gamma production. All patients developed grade 1-3 cytokine release syndrome (CRS) with elevated serum IL-6 and interferon-gamma.

Activated granulocytes and inflammatory cytokine signaling drive T-cell lymphoma progression and disease symptoms

Peripheral T-cell lymphomas (PTCLs), especially angioimmunoblastic and follicular TCLs, have a dismal prognosis because of the lack of efficient therapies, and patients' symptoms are often dominated by an inflammatory phenotype, including fever, night sweats, weight loss, and skin rash. In this study, we investigated the role of inflammatory granulocytes and activated cytokine signaling on T-cell follicular helper-type PTCL (TFH-PTCL) disease progression and symptoms. We showed that ITK-SYK-driven murine PTCLs and primary human TFH-PTCL xenografts both induced inflammation in mice, including murine neutrophil expansion and massive cytokine release. Granulocyte/lymphoma interactions were mediated by positive autoregulatory cytokine loops involving interferon gamma (CD4+ malignant T cells) and interleukin 6 (IL-6; activated granulocytes), ultimately inducing broad JAK activation (JAK1/2/3 and TYK2) in both cell types. Inflammatory granulocyte depletion via antibodies (Ly6G), genetic granulocyte depletion (LyzM-Cre/MCL1flox/flox), or IL-6 deletion within microenvironmental cells blocked inflammatory symptoms, reduced lymphoma infiltration, and enhanced mouse survival. Furthermore, unselective JAK inhibitors (ruxolitinib) inhibited both TCL progression and granulocyte activation in various PTCL mouse models. Our results support the important role of granulocyte-driven inflammation, cytokine-induced granulocyte/CD4+ TCL interactions, and an intact JAK/STAT signaling pathway for TFH-PTCL development and also support broad JAK inhibition as an effective treatment strategy in early disease stages.

Low-density granulocytes in systemic autoimmunity and autoinflammation

A body of evidence has re-energized the interest on the role neutrophils in inflammatory and autoimmune conditions. For decades, neutrophils have been considered a homogenous population. Nevertheless, accumulating evidence suggests that neutrophils are more versatile and heterogeneous than initially considered. The notion of neutrophil heterogeneity has been supported by the identification of low-density granulocytes (LDGs) in systemic lupus erythematosus (SLE) and other systemic autoimmune and autoinflammatory conditions. Transcriptomic, epigenetic, proteomic, and functional analyses support that LDGs are a distinct subset of proinflammatory neutrophils implicated in the pathogenesis of SLE and other autoimmune diseases. Importantly, it remains incompletely characterized whether LDGs detected in other inflammatory/autoimmune conditions display the same phenotype that those present in SLE. A shared feature of LDGs across diseases is their association with vascular damage, an important contributor to morbidity and mortality in chronic inflammatory conditions. Additionally, the lack of specific markers to identify LDGs in circulation or in tissue, makes it a challenge to elucidate their role in the pathogenesis of inflammatory and autoimmune conditions. In this review, we aim to examine the evidence on the biology and the putative pathogenic role of LDGs in systemic autoimmune diseases.

Multiparameter flow cytometry in the evaluation of myelodysplasia: Analytical issues: Recommendations from the European LeukemiaNet/International Myelodysplastic Syndrome Flow Cytometry Working Group

Multiparameter flow cytometry (MFC) is one of the essential ancillary methods in bone marrow (BM) investigation of patients with cytopenia and suspected myelodysplastic syndrome (MDS). MFC can also be applied in the follow-up of MDS patients undergoing treatment. This document summarizes recommendations from the International/European Leukemia Net Working Group for Flow Cytometry in Myelodysplastic Syndromes (ELN iMDS Flow) on the analytical issues in MFC for the diagnostic work-up of MDS. Recommendations for the analysis of several BM cell subsets such as myeloid precursors, maturing granulocytic and monocytic components and erythropoiesis are given. A core set of 17 markers identified as independently related to a cytomorphologic diagnosis of myelodysplasia is suggested as mandatory for MFC evaluation of BM in a patient with cytopenia. A myeloid precursor cell (CD34⁺ CD19^- ) count >3% should be considered immunophenotypically indicative of myelodysplasia. However, MFC results should always be evaluated as part of an integrated hematopathology work-up. Looking forward, several machine-learning-based analytical tools of interest should be applied in parallel to conventional analytical methods to investigate their usefulness in integrated diagnostics, risk stratification, and potentially even in the evaluation of response to therapy, based on MFC data. In addition, compiling large uniform datasets is desirable, as most of the machine-learning-based methods tend to perform better with larger numbers of investigated samples, especially in such a heterogeneous disease as MDS.

Use of nab-paclitaxel and gemcitabine in pancreatic cancer without granulocyte colony-stimulating factor: A multicenter real-world experience

INTRODUCTION

The metastatic pancreatic adenocarcinoma clinical trial (MPACT) trial established gemcitabine (gem) and nab-paclitaxel (nab) as a standard treatment for pancreatic cancer utilizing granulocyte colony-stimulating factors to manage neutropenia. This was a challenge for jurisdictions that do not use granulocyte colony-stimulating factors in palliative settings. We developed dosage guidelines to dose modify gem and nab without granulocyte colony-stimulating factors. We undertook a retrospective review to determine the efficacy and safety of these dose adjustment guidelines in the real world.

METHODS

A multi-centered, retrospective chart review was performed on pancreatic patients between December 1, 2014, and August 21, 2018. Provincial electronic medical health records were reviewed. Using Log-rank statistics we determined the patient's progression-free survival and overall survival.

RESULTS

Of 248 patients, 209 met patient selection criteria. Patients were excluded if they were lost to follow-up, on gem alone prior to nab/gem combination therapy or did not receive nab or gem. Patients who received nab/gem as first-line therapy had a median progression-free survival of 6.3 months (95% CI, 5.1-7.4), and median overall survival of 11.1 months (95% CI, 9.5-12.8). Those who received gem/nab in the second line had a median progression-free survival of 4.6 months (95% CI, 2.8-6.5), and median overall survival of 19.3 months (95% CI, 12.6-26.0).

CONCLUSIONS

The patient's progression-free survival and overall survival taking nab/gem using our dose modification algorithm were equivalent or superior to the MPACT trial's progression-free survival and overall survival. Gem/nab can be given by our dose modification scheme without granulocyte colony-stimulating factor.

Utility of immature granulocyte in severity of helicobacter pylori infection

INTRODUCTION

Helicobacter pylori infection is a chronic bacterial infection associated with some extragastric diseases as well as gastric involvements that occur most commonly worldwide. In our study, we aimed to investigate the usability of immature granulocytes as a basic indicator that can reflect the severity of helicobacter pylori inflammation, to the best of our knowledge, for the first time.

MATERIALS AND METHODS

Patients who underwent upper gastrointestinal endoscopy between April 2019 and April 2020 and were diagnosed with antral gastritis were included in this study. The relationship between helicobacter infection and its severity detected in gastric biopsies of patients and immature granulocyte count (IGC), immature granulocyte percentage (IG%), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and mean platelet volume (MPV) were investigated.

RESULTS

Of the 868 patients, 210 were HP negative, 658 were HP positive (218 mild HP positive, 293 moderate HP positive, and 147 severe HP positive). There were statistically significant differences between the HP negative and HP positive groups in terms of IGC, IG%, NLR, and PLR. However, IG% and IGC were not clinically useful because the median IG% (0.3 vs 0.3) and IGC (0.02 vs 0.02) were the same in the HP negative and total HP positive groups.

CONCLUSION

In our study, IGC and IG% were not found useful to detect H. pylori intensity and severity of inflammation.

Two distinct subsets of LDGs (low density granulocytes) in ANCA-associated vasculitis

OBJECTIVES AND METHODS

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is an autoimmune disorder that causes vasculitis in small blood vessels throughout the body. Low-density granulocytes (LDGs) in autoimmune diseases, such as SLE and AAV, might play a critical role in the pathogenesis of these diseases. Here, we aimed to determine the characteristics of LDGs in patients with AAV. We assessed the number of whole white blood cells, neutrophil extracellular traps (NETs) productivity, proportion of cell surface markers (e.g. CD10), responses to immunosuppressants, and proteomics of LDGs in patients with AAV.

RESULTS

We found more LDGs in peripheral blood mononuclear cells (PBMCs) of patients with AAV than PBMCs of healthy controls (HCs) and confirmed that these LDGs in AAV produced more NETs than normal density granulocytes (NDGs) in HCs. We identified CD10-positive LDGs with mature neutrophil features and CD10-negative LDGs with immature granulocyte properties; the proportion of the two LDG types decreased and increased, respectively, in the patients during treatment. Proteomic analysis revealed that the two LDG groups shared protein expression that differed from those of NDGs.

CONCLUSION

We identified distinct CD10-positive and CD10-negative LDGs in patients with AAV. The roles of these LDGs in AAV pathology will require further investigation.

Pig-a gene mutations in bone marrow granulocytes of procarbazine-treated F344 rats

It was previously demonstrated that procarbazine (PCZ) is positive in the rat erythrocyte Pig-a gene mutation assay. However, since mammalian erythrocytes lack genomic DNA, it was necessary to analyze nucleated bone-marrow erythroid precursor cells to confirm that PCZ induces mutations in the Pig-a gene (Revollo et al., Environ Mol Mutagen, 2020). In this study, the association between Pig-a mutation and loss of GPI anchors was further strengthened and the genesis of Pig-a mutation in PCZ-dosed rats was evaluated by analyzing bone-marrow granulocytes. Erythrocytes and granulocytes both originate from myeloid progenitor cells, but granulocytes contain DNA throughout their developmental stages. F344 rats were treated with three doses of 150 mg/kg PCZ; 2 weeks later, CD48-deficient mutant phenotype bone-marrow granulocytes (BMGs [CD11b⁺ ]) were isolated by flow-cytometric sorting. Sequencing data showed that the CD48-deficient mutant phenotype BMGs contained mutations in the Pig-a gene while wild-type BMGs did not. PCZ-induced mutations included missense, nonsense and splice site variants; the majority of mutations were A > T, A > C, and A > G, with the mutated A on the nontranscribed DNA strand. The PCZ-induced mutational analysis in BMGs supports the association between the phenotype measured in the Pig-a assay and mutation in the Pig-a gene. Also, PCZ mutation spectra were similar in bone-marrow erythroids and BMGs, but none of the mutations detected in BMGs were the same as the erythroid precursor cell mutations from the same rats. Thus, mutations induced in the Pig-a assay appear to be induced after commitment of myeloid progenitor cells to either the granulocyte or erythroid pathway.

HDN-1 induces cell differentiation toward apoptosis in promyelocytic leukemia cells depending on its selective effect on client proteins of Hsp90

Heat Shock Protein 90 (Hsp90) is frequently upregulated in many cancers, and its inhibition simultaneously blocks multiple signaling pathways, resulting in cell differentiation or apoptosis. However, the complexity of Hsp90 in differentiation and its relation with apoptosis have remained unsettled. In this study, we demonstrated that HDN-1, a C-terminal inhibitor of Hsp90, induced the differentiation of HL-60 cells toward apoptosis. HDN-1 induced the differentiation of cells containing mutant AML1-ETO into mature granulocytes, which was related to its selective effect on client proteins of Hsp90. HDN-1 destabilized AML1-ETO and preserved C/EBPβ at the same time, thereby induced a total increase in C/EBPβ levels because of AML1-ETO negative regulation to C/EBPβ expression. Neither HDN-1 nor 17-AAG (an N-terminal inhibitor of Hsp90) led to the differentiation of NB4 cells because mutant PML-RARα was not affected as a client protein of Hsp90; thus, no additional expression of C/EBPβ was induced. 17-AAG did not affect the differentiation of HL-60 cells due to decreased AML1-ETO and C/EBPβ levels. These results indicate that HDN-1 drives cell differentiation toward apoptosis depending on its selective influence on client proteins of Hsp90, establishing the relationship between differentiation and apoptosis and uncovering the mechanism of HDN-1 in promyelocytic leukemia cell differentiation. Moreover, HDN-1 is very promising for the development of anticancer agents with the induction of differentiation.

Ion and Water Transport in Neutrophil Granulocytes and Its Impairment during Sepsis

Neutrophil granulocytes are the vanguard of innate immunity in response to numerous pathogens. Their activity drives the clearance of microbe- and damage-associated molecular patterns, thereby contributing substantially to the resolution of inflammation. However, excessive stimulation during sepsis leads to cellular unresponsiveness, immunological dysfunction, bacterial expansion, and subsequent multiple organ dysfunction. During the short lifespan of neutrophils, they can become significantly activated by complement factors, cytokines, and other inflammatory mediators. Following stimulation, the cells respond with a defined (electro-)physiological pattern, including depolarization, calcium influx, and alkalization as well as with increased metabolic activity and polarization of the actin cytoskeleton. Activity of ion transport proteins and aquaporins is critical for multiple cellular functions of innate immune cells, including chemotaxis, generation of reactive oxygen species, and phagocytosis of both pathogens and tissue debris. In this review, we first describe the ion transport proteins and aquaporins involved in the neutrophil ion-water fluxes in response to chemoattractants. We then relate ion and water flux to cellular functions with a focus on danger sensing, chemotaxis, phagocytosis, and oxidative burst and approach the role of altered ion transport protein expression and activity in impaired cellular functions and cell death during systemic inflammation as in sepsis.

Administration of Human MSC-Derived Extracellular Vesicles for the Treatment of Primary Sclerosing Cholangitis: Preclinical Data in MDR2 Knockout Mice

Primary Sclerosing Cholangitis (PSC) is a progressive liver disease for which there is no effective medical therapy. PSC belongs to the family of immune-mediated biliary disorders and it is characterized by persistent biliary inflammation and fibrosis. Here, we explored the possibility of using extracellular vesicles (EVs) derived from human, bone marrow mesenchymal stromal cells (MSCs) to target liver inflammation and reduce fibrosis in a mouse model of PSC. Five-week-old male FVB.129P2-Abcb4tm1Bor mice were intraperitoneally injected with either 100 µL of EVs (± 9.1 × 109 particles/mL) or PBS, once a week, for three consecutive weeks. One week after the last injection, mice were sacrificed and liver and blood collected for flow cytometry analysis and transaminase quantification. In FVB.129P2-Abcb4tm1Bor mice, EV administration resulted in reduced serum levels of alkaline phosphatase (ALP), bile acid (BA), and alanine aminotransferase (ALT), as well as in decreased liver fibrosis. Mechanistically, we observed that EVs reduce liver accumulation of both granulocytes and T cells and dampen VCAM-1 expression. Further analysis revealed that the therapeutic effect of EVs is accompanied by the inhibition of NFkB activation in proximity of the portal triad. Our pre-clinical experiments suggest that EVs isolated from MSCs may represent an effective therapeutic strategy to treat patients suffering from PSC.

Interaction between Fibroblasts and Immune Cells Following DNA Damage Induced by Ionizing Radiation

Cancer-associated fibroblasts (CAF) form the basis of tumor microenvironment and possess immunomodulatory functions by interacting with other cells surrounding tumor, including T lymphocytes, macrophages, dendritic cells and natural killer cells. Ionizing radiation is a broadly-used method in radiotherapy to target tumors. In mammalian cells, ionizing radiation induces various types of DNA damages and DNA damage response. Being unspecific, radiotherapy affects all the cells in tumor microenvironment, including the tumor itself, CAFs and immune cells. CAFs are extremely radio-resistant and do not initiate apoptosis even at high doses of radiation. However, following radiation, CAFs become senescent and produce a distinct combination of immunoregulatory molecules. Radiosensitivity of immune cells varies depending on the cell type due to inefficient DNA repair in, for example, monocytes and granulocytes. In this minireview, we are summarizing recent findings on the interaction between CAF, ionizing radiation and immune cells in the tumor microenvironment.

The clinical significance of PNH-phenotype cells accounting for < 0.01% of total granulocytes detected by the Clinical and Laboratory Standards Institute methods in patients with bone marrow failure

Small populations of glycosylphosphatidylinositol-anchored protein-deficient (GPI[-]) cells accounting for up to 0.01% of total granulocytes can be accurately detected by a high-sensitivity flow cytometry (FCM) assay established by the Clinical and Laboratory Standards Institute (CLSI method) and have a prognostic value in bone marrow failure (BMF); however, the significance of GPI(-) granulocytes accounting for 0.001-0.009% of granulocytes remains unclear. To clarify this issue, we examined the peripheral blood of 21 BMF patients in whom minor (around 0.01%) populations of GPI(-) granulocytes had been previously detected by a different high-resolution FCM method (OPTIMA method, which defines ≥ 0.003% GPI(-) granulocytes as an abnormal increase) using both the CLSI and OPTIMA methods simultaneously. These two methods detected an "abnormal increase" in GPI(-) granulocytes in 10 patients (48%) and 17 patients (81%), respectively. CLSI detected 0.002-0.005% (median, 0.004%) GPI(-) granulocytes in 7 patients who were deemed positive for PNH-type cells according to the OPTIMA method, which detected 0.003-0.012% (median 0.006%) GPI(-) granulocytes. The clone sizes of GPI(-) cells detected by each assay were positively correlated (r = 0.994, p < 0.001). Of the seven patients who were judged positive for PNH-type cells by OPTIMA alone, five received immunosuppressive therapy, and all of them achieved a partial or complete response. GPI(-) granulocytes detected in BMF patients by the CLSI method should thus be considered significant, even at percentages of < 0.01%.

Sialadenitis in a patient with ulcerative colitis and autoimmune pancreatitis type 2

Autoimmune pancreatitis (AIP) is a distinct form of chronic pancreatitis that has been increasingly recognised over the last decades and shows a good response to corticosteroid treatment. Two different forms of AIP have been characterized. Type 1 AIP is the pancreatic manifestation of IgG4-related disease and often affects multiple organ systems. In contrast, type 2 AIP is confined to the pancreas and involvement of extra-pancreatic organs has previously only very rarely been reported, except for an association with inflammatory bowel disease. The hallmark lesion of type 2 AIP is the granulocyte epithelial lesion (GEL), showing infiltration of neutrophilic granulocytes in the epithelium of pancreatic ducts and their accumulation in the duct lumen. We present a 61-year-old female patient who underwent pancreaticoduodenectomy with a postoperative histological diagnosis of type 2 AIP. Three months later, she underwent colectomy and was diagnosed with ulcerative colitis. One year later, she presented with swelling and pain of the right-sided submandibular salivary gland which was resected. Sialadenitis with lymphoplasmacytic inflammation, obliterative phlebitis, fibrosis and frequent accumulation of neutrophilic granulocytes in ducts, reminiscent of GELs, without IgG4-positivity or epitheloid cell granulomas, was found. Later, she presented with swelling and pain related to the left-sided submandibular gland, which resolved after steroid treatment. We describe the clinical, histological and immunohistochemical findings in this patient. It may be hypothesized that the sialadenitis may represent a rare extrapancreatic manifestation of, alternatively a rare association with, type 2 AIP or ulcerative colitis.

Blame the signaling: Role of cAMP for the resolution of inflammation

A complex intracellular signaling governs different cellular responses in inflammation. Extracellular stimuli are sensed, amplified, and transduced through a dynamic cellular network of messengers converting the first signal into a proper response: production of specific mediators, cell activation, survival, or death. Several overlapping pathways are coordinated to ensure specific and timely induction of inflammation to neutralize potential harms to the tissue. Ideally, the inflammatory response must be controlled and self-limited. Resolution of inflammation is an active process that culminates with termination of inflammation and restoration of tissue homeostasis. Comparably to the onset of inflammation, resolution responses are triggered by coordinated intracellular signaling pathways that transduce the message to the nucleus. However, the key messengers and pathways involved in signaling transduction for resolution are still poorly understood in comparison to the inflammatory network. cAMP has long been recognized as an inducer of anti-inflammatory responses and cAMP-dependent pathways have been extensively exploited pharmacologically to treat inflammatory diseases. Recently, cAMP has been pointed out as coordinator of key steps of resolution of inflammation. Here, we summarize the evidence for the role of cAMP at inducing important features of resolution of inflammation.

Baseline clinical characteristics and disease burden in patients with paroxysmal nocturnal hemoglobinuria (PNH): updated analysis from the International PNH Registry

The International Paroxysmal Nocturnal Hemoglobinuria (PNH) Registry (NCT01374360) was initiated to optimize patient management by collecting data regarding disease burden, progression, and clinical outcomes. Herein, we report updated baseline demographics, clinical characteristics, disease burden data, and observed trends regarding clone size in the largest cohort of Registry patients. Patients with available data as of July 2017 were stratified by glycosylphosphatidylinositol (GPI)-deficient granulocyte clone size (< 10%, ≥ 10%-< 50%, and ≥ 50%). All patients were untreated with eculizumab at baseline, defined as date of eculizumab initiation or date of Registry enrollment (if never treated with eculizumab). Outcomes assessed in the current analysis included proportions of patients with high disease activity (HDA), history of major adverse vascular events (MAVEs; including thrombotic events [TEs]), bone marrow failure (BMF), red blood cell (RBC) transfusions, and PNH-related symptoms. A total of 4439 patients were included, of whom 2701 (60.8%) had available GPI-deficient granulocyte clone size data. Among these, median clone size was 31.8% (1002 had < 10%; 526 had ≥ 10%-< 50%; 1173 had ≥ 50%). There were high proportions of patients with HDA (51.6%), history of MAVEs (18.8%), BMF (62.6%), RBC transfusion (61.3%), and impaired renal function (42.8%). All measures except RBC transfusion history significantly correlated with GPI-deficient granulocyte clone size. A large proportion of patients with GPI-deficient granulocyte clone size < 10% had hemolysis (9.7%), MAVEs (10.2%), HDA (9.1%), and/or PNH-related symptoms. Although larger GPI-deficient granulocyte clone sizes were associated with higher disease burden, a substantial proportion of patients with smaller clone sizes had history of MAVEs/TEs.

Immunomodulation in Cystic Fibrosis: Why and How?

Cystic fibrosis (CF) lung disease is characterized by unconventional mechanisms of inflammation, implicating a chronic immune response dominated by innate immune cells. Historically, therapeutic development has focused on the mutated cystic fibrosis transmembrane conductance regulator (CFTR), leading to the discovery of small molecules aiming at modulating and potentiating the presence and activity of CFTR at the plasma membrane. However, treatment burden sustained by CF patients, side effects of current medications, and recent advances in other therapeutic areas have highlighted the need to develop novel disease targeting of the inflammatory component driving CF lung damage. Furthermore, current issues with standard treatment emphasize the need for directed lung therapies that could minimize systemic side effects. Here, we summarize current treatment used to target immune cells in the lungs, and highlight potential benefits and caveats of novel therapeutic strategies.

Tumor-infiltrating and circulating granulocytic myeloid-derived suppressor cells correlate with disease activity and adverse clinical outcomes in mycosis fungoides

PURPOSE

Cutaneous T cell lymphomas (CTCL) are rare and histologically diverse lymphoproliferative neoplasms, with mycosis fungoides (MF) representing the most common disease subset. Given the emerging role of myeloid-derived suppressor cells (MDSC) as a clinically applicable biomarker in solid tumors, we sought to investigate the presence of tumor-infiltrating and circulating MDSC in early- and advanced-stage MF patients and evaluate their prognostic significance in patient overall survival.

METHODS

Tumor-infiltrating MDSC were assessed immunohistochemically with Arginase-1 in 31 MF and 14 non-MF skin punch biopsies. Circulating MDSC were assessed with flow cytometry in freshly isolated PBMC from 29 MF patients. Granulocytic MDSC (G-MDSC) were defined as CD11b+CD14-CD15+ and monocytic MDSC (M-MDSC) were defined as CD11b+CD14+HLA-DRlow/-.

RESULTS

MDSC infiltration occurred in approximately one-third (35.5%) of CTCL lesions, with a predilection for non-MF lesions (p < 0.05). The predominant morphology of MDSC was granulocytic. Although in MF lesions the presence of MDSC infiltrates did not correlate with clinical stage, it conferred significantly worse overall survival outcomes (p < 0.05). Circulating G-MDSC were significantly higher in MF patients compared to healthy donor controls (p < 0.0001), while M-MDSC did not show any statistically significant difference. G-MDSC were significantly higher in patients with active disease compared to patients who were in partial remission (p < 0.01). As with tumor-infiltrating MDSC, clinical stage did not correlate with circulating G-MDSC levels, while prospective overall survival analysis showed that patients with high levels of circulating G-MDSC have significantly inferior outcomes (p < 0.01).

CONCLUSIONS

This study shows that G-MDSC could represent a novel and easily assessable biomarker in MF, which mirrors disease activity and can predict patient subgroups with aggressive clinical features.

Inducible histone K-to-M mutations are dynamic tools to probe the physiological role of site-specific histone methylation in vitro and in vivo

Development and differentiation are associated with profound changes to histone modifications, yet their in vivo function remains incompletely understood. Here, we generated mouse models expressing inducible histone H3 lysine-to-methionine (K-to-M) mutants, which globally inhibit methylation at specific sites. Mice expressing H3K36M developed severe anaemia with arrested erythropoiesis, a marked haematopoietic stem cell defect, and rapid lethality. By contrast, mice expressing H3K9M survived up to a year and showed expansion of multipotent progenitors, aberrant lymphopoiesis and thrombocytosis. Additionally, some H3K9M mice succumbed to aggressive T cell leukaemia/lymphoma, while H3K36M mice exhibited differentiation defects in testis and intestine. Mechanistically, induction of either mutant reduced corresponding histone trimethylation patterns genome-wide and altered chromatin accessibility as well as gene expression landscapes. Strikingly, discontinuation of transgene expression largely restored differentiation programmes. Our work shows that individual chromatin modifications are required at several specific stages of differentiation and introduces powerful tools to interrogate their roles in vivo.

A subset of low density granulocytes is associated with vascular calcification in chronic kidney disease patients

Inflammation is central to chronic kidney disease (CKD) pathogenesis and vascular outcomes, but the exact players remain unidentified. Since low density granulocytes (LDGs) are emerging mediators in inflammatory conditions, we aimed to evaluate whether LDGs may be altered in CKD and related to clinical outcomes as biomarkers. To his end, LDGs subsets were measured in peripheral blood by flow cytometry and confocal microscopy in 33 CKD patients undergoing peritoneal dialysis and 15 healthy controls (HC). Analyses were replicated in an additional cohort. DEF3 (marker of early granulopoiesis) gene expression on PBMCs was quantified by qPCR. Total CD15+ LDGs and both CD14lowCD16+ and CD14-CD16- subsets were expanded in CKD. The relative frequency of the CD14-CD16- subpopulation was higher among the CD15+ pool in CKD. This alteration was stable over-time. The increased CD14-CD16-CD15+ paralleled Kauppila scores and DEF3 expression, whereas no association was found with CD14lowCD16+ CD15+. Both subsets differed in their CD11b, CD10, CD35, CD31, CD62L, IFNAR1 and CD68 expression, FSC/SSC features and nuclear morphology, pointing to different origins and maturation status. In conclusion, LDGs were expanded in CKD showing a skewed distribution towards a CD14-CD16-CD15+ enrichment, in association with vascular calcification. DEF3 expression in PBMC can be a marker of LDG expansion.

Myeloid-derived suppressor cells endow stem-like qualities to multiple myeloma cells by inducing piRNA-823 expression and DNMT3B activation

BACKGROUND

Myeloid-derived suppressor cells (MDSCs) and cancer stem cells (CSCs) are two important cellular components in the tumor microenvironment, which may modify the cancer phenotype and affect patient survival. However, the crosstalk between MDSCs and multiple myeloma stem cells (MMSCs) are relatively poorly understood.

METHODS

The frequencies of granulocytic-MDSCs (G-MDSCs) in MM patients were detected by flow cytometry and their association with the disease stage and patient survival were analyzed. RT-PCR, flow cytometry, western blot and sphere formation assays were performed to investigate the effects of G-MDSCs, piRNA-823 and DNA methylation on the maintenance of stemness in MM. Then a subcutaneous tumor mouse model was constructed to analyze tumor growth and angiogenesis after G-MDSCs induction and/or piRNA-823 knockdown in MM cells.

RESULTS

Our clinical dataset validated the association between high G-MDSCs levels and poor overall survival in MM patients. In addition, for the first time we showed that G-MDSCs enhanced the side population, sphere formation and expression of CSCs core genes in MM cells. Moreover, the mechanism study showed that G-MDSCs triggered piRNA-823 expression, which then promoted DNA methylation and increased the tumorigenic potential of MM cells. Furthermore, silencing of piRNA-823 in MM cells reduced the stemness of MMSCs maintained by G-MDSCs, resulting in decreased tumor burden and angiogenesis in vivo.

CONCLUSION

Altogether, these data established a cellular, molecular, and clinical network among G-MDSCs, piRNA-823, DNA methylation and CSCs core genes, suggesting a new anti-cancer strategy targeting both G-MDSCs and CSCs in MM microenvironment.

The Role of Acrolein and NADPH Oxidase in the Granulocyte-Mediated Growth-Inhibition of Tumor Cells

Although granulocytes are the most abundant leukocytes in human blood, their involvement in the immune response against cancer is not well understood. While granulocytes are known for their “oxidative burst” when challenged with tumor cells, it is less known that oxygen-dependent killing of tumor cells by granulocytes includes peroxidation of lipids in tumor cell membranes, yielding formation of reactive aldehydes like 4-hydroxynonenal (4-HNE) and acrolein. In the present work, we investigate the role of reactive aldehydes on cellular redox homeostasis and surface toll-like receptor 4 (TLR4) expression. We have further study the granulocyte-tumor cell intercellular redox signaling pathways. The data obtained show that granulocytes in the presence of 4-HNE and acrolein induce excessive ROS formation in tumor cells. Acrolein was also shown to induce granulocyte TLR4 expression. Furthermore, granulocyte-mediated antitumor effects were shown to be mediated via HOCl intracellular pathway by the action of NADPH oxidase. However, further studies are needed to understand interaction between TLR4 and granulocyte-tumor cell intercellular signaling pathways.

Gravitational stress during parabolic flights reduces the number of circulating innate and adaptive leukocyte subsets in human blood

Gravitational stress occurs during space flights or certain physical activities including extreme sports, where the change in experienced gravitational acceleration can reach large magnitudes. These changes include reduction and increase in the physical forces experienced by the body and may potentially induce pathogenic alterations of physiological processes. The immune system is known to regulate most functions in the human organism and previous studies suggest an impairment of the immune function under gravitational stress. However, systematic studies aiming to investigate the effect of gravitational stress on cellular immune response in humans are lacking. Since parabolic flights are considered as feasible model to investigate a short-term impact of gravitational changes, we evaluated the influence of gravitational stress on the immune system by analyzing leukocyte numbers before and after parabolic flight maneuvers in human blood. To correct for circadian effects, samples were taken at the corresponding time points on ground the day before the flight. The parabolic flight maneuvers led to changes in numbers of different leukocyte subsets. Naïve and memory T and B cell subsets decreased under gravitational stress and lower numbers of basophils and eosinophils were observed. Only circulating neutrophils increased during the parabolic flight. The observed changes could not be attributed to stress-induced cortisol effects, since cortisol levels were not affected. Our data demonstrate that the gravitational stress by parabolic flights can affect all parts of the human immune system. Consequently, it is possible that gravitational stress can have clinically relevant impacts on the control of immune responses.

Inter-observer variance and the need for standardization in the morphological classification of myelodysplastic syndrome

In this era of genome medicine, the sub-classification of myeloid neoplasms, including myelodysplastic syndrome (MDS), is now supported by genetic testing in selected cases. However, as the initial suspicion and primary diagnosis of the disease still largely relies on morphological features and numbers of hematopoietic cells, the establishment of a uniform diagnostic basis, especially for cell morphology, is essential. In this study, we collected nearly 100,000 hematopoietic cell images from 499 peripheral blood smear specimens from patients with MDS and used these to evaluate the standardization of morphological classification by medical technologists. The observers in this study ranged between two to eleven for each image, and the images were classified according to MDS criteria through a web-based system. We found considerable inter-observer variance in the assessment of dysplastic features. Observers did not recognize cytoplasmic hypo-granularity unless almost all granules in neutrophils were absent. Pseudo Pelger-Huët anomalies were also often overlooked, except for cells with a very typical "pince-nez" appearance. Taken together, this study suggests a requirement for further standardization in terms of morphological cell classification, and a need for the development of automatic cell classification-supporting devices for the accurate diagnosis of MDS.

Beware the intruder: Real time observation of infiltrated neutrophils and neutrophil-Microglia interaction during stroke in vivo

Inflammation plays an important role in the pathogenesis of ischemic stroke including an acute and prolonged inflammatory process. The role of neutrophil granulocytes as first driver of the immune reaction from the blood site is under debate due to controversial findings. In bone marrow chimeric mice we were able to study the dynamics of tdTomato-expressing neutrophils and GFP-expressing microglia after photothrombosis using intravital two-photon microscopy. We demonstrate the infiltration of neutrophils into the brain parenchyma and confirm a long-lasting contact between neutrophils and microglia as well as an uptake of neutrophils by microglia clearing the brain from peripheral immune cells.

Model-based optimization of G-CSF treatment during cytotoxic chemotherapy

PURPOSE

Although G-CSF is widely used to prevent or ameliorate leukopenia during cytotoxic chemotherapies, its optimal use is still under debate and depends on many therapy parameters such as dosing and timing of cytotoxic drugs and G-CSF, G-CSF pharmaceuticals used and individual risk factors of patients.

METHODS

We integrate available biological knowledge and clinical data regarding cell kinetics of bone marrow granulopoiesis, the cytotoxic effects of chemotherapy and pharmacokinetics and pharmacodynamics of G-CSF applications (filgrastim or pegfilgrastim) into a comprehensive model. The model explains leukocyte time courses of more than 70 therapy scenarios comprising 10 different cytotoxic drugs. It is applied to develop optimized G-CSF schedules for a variety of clinical scenarios.

RESULTS

Clinical trial results showed validity of model predictions regarding alternative G-CSF schedules. We propose modifications of G-CSF treatment for the chemotherapies 'BEACOPP escalated' (Hodgkin's disease), 'ETC' (breast cancer), and risk-adapted schedules for 'CHOP-14' (aggressive non-Hodgkin's lymphoma in elderly patients).

CONCLUSIONS

We conclude that we established a model of human granulopoiesis under chemotherapy which allows predictions of yet untested G-CSF schedules, comparisons between them, and optimization of filgrastim and pegfilgrastim treatment. As a general rule of thumb, G-CSF treatment should not be started too early and patients could profit from filgrastim treatment continued until the end of the chemotherapy cycle.

Decreased miR-17-92 cluster expression level in serum and granulocytes preceding onset of antithyroid drug-induced agranulocytosis

PURPOSE

We aimed to determine changes in miR-17-92 cluster expression in serum and granulocytes from patients with antithyroid drug (ATD)-induced agranulocytosis.

METHODS

In this study, real-time polymerase chain reaction (PCR) was used to detect serum miR-17-92 expression levels in 20 ATD-induced agranulocytosis and 16 control patients. Importantly, dynamic changes in neutrophil counts from granulocytopenia to agranulocytosis were observed in 6 of the 20 patients. miR-17-92 expression levels in granulocytes of those six patients under the granulocytopenia condition were measured and compared with corresponding granulocyte samples after recovery. Additionally, the expression levels of these miRNAs in patients with type I or type II bone marrow characteristics were analyzed, and the correlation between miR-17-92 and serum free thyroxine level was analyzed.

RESULTS

We found that levels of miR-17-92 expression decreased in both serum and pre-agranulocytosis granulocytes from patients with ATD-induced agranulocytosis compared with those in serum and granulocytes from both recovered patients and control patients. However, no difference among patients with either type of bone marrow characteristics was observed, and no correlation between serum miR-17-92 and free thyroxine levels was found.

CONCLUSION

In ATD-induced agranulocytosis, expression of the miR-17-92 cluster is reduced in both serum and granulocytes, though this alteration does not correlate with bone marrow characteristics or thyroid function.

Histiocytoid autoimmunity-related neutrophilic dermatosis in a patient with rheumatoid arthritis

Autoimmunity-associated neutrophilic dermatoses are a recently recognized manifestation of connective tissue diseases, in particular, lupus erythematosus. These entities are clinically and sometimes histopathologically distinct from classic neutrophilic dermatoses. We describe a case of an autoimmunity-related neutrophilic dermatosis in a patient with rheumatoid arthritis. In addition to this uncommon association, there was an absence of mature neutrophils and a population of immature histiocytoid granulocytes. This unusual case expands the concept of histiocytoid neutrophilic dermatoses to include those seen in association with autoimmune connective tissue diseases.

Granulocytic myeloid-derived suppressor cells suppress virus-specific CD8+ T cell responses during acute Friend retrovirus infection

BACKGROUND

Myeloid-derived suppressor cells (MDSCs) can suppress T cell responses in several different diseases. Previously these suppressive cells were observed to expand in HIV patients and in a mouse retrovirus model, yet their suppressive effect on virus-specific CD8+ T cells in vitro and in vivo has not been characterized thus far.

RESULTS

We used the Friend retrovirus (FV) model to demonstrate that MDSCs expand and become activated during the late phase of acute FV infection. Only the subpopulation of granulocytic MDSCs (gMDSCs) but not monocytic MDSC suppressed virus-specific CD8+ T cell proliferation and function in vitro. gMDSCs expressed arginase 1, high levels of the inhibitory ligand PD-L1 and the ATP dephosphorylating enzyme CD39 on the cell surface upon infection. All three molecules were involved in the suppressive effect of the gMDSCs in vitro. MDSC depletion experiments in FV-infected mice revealed that they restrict virus-specific CD8+ T cell responses and thus affect the immune control of chronic retroviruses in vivo.

CONCLUSIONS

Our study demonstrates that MDSCs become activated and expand during the acute phase of retrovirus infection. Their suppressive activity on virus-specific CD8+ T cells may contribute to T cell dysfunction and the development of chronic infection.

Distinct clinical characteristics of paroxysmal nocturnal hemoglobinuria in patients in Southern Taiwan: A multicenter investigation

Paroxysmal nocturnal hemoglobinuria (PNH) is an extremely rare acquired disorder. The aim of this study was to investigate the demographics, clinical manifestations, and outcomes of PNH patients in southern Taiwan. Data on PNH patients diagnosed over a 30-year period (1985-2015) were retrospectively collected from four tertiary medical centers in southern Taiwan. Blood samples were collected for hematologic panel testing and flow cytometry detection of PNH clones. Radiologic studies were performed to assess the frequency of complications. Twenty-four patients were enrolled in this study. The median duration of disease in the study participants was 10.8 years. The median granulocyte PNH clone size was 92.5% (range, 1.3%-99.8%), and the median lactate dehydrogenase (LDH) level was 2920.2 ± 1462.0 IU/L. The incidence of thromboembolism and impaired renal function was 16.7% and 29.2%, respectively. The primary treatment strategies included steroids (79.2%), androgens (42.0%), eculizumab (33.3%), immunosuppressants (16.7%), and anticoagulants (4.2%). In eight patients treated with eculizumab, there was a marked reduction in the LDH levels of 14.89-fold-1.63-fold that of the upper limit of normal; seven patients exhibited decreased transfusion requirements. Twenty-one patients were alive with regular follow-up at the time of publication. Our study demonstrates that PNH patients in southern Taiwan may exhibit different clinical characteristics and outcomes relative to patients in other countries. There was a trend toward a greater PNH granulocyte clone size, which may lead to more hemolysis. In our study, the percentage of patients with impaired renal function, but not the percentage of patients with thrombotic events, was higher than values reported worldwide and in the observational cross-sectional International PNH Registry. More large-scale studies with comprehensive data on the clinical response to different treatments are needed.

Blood Stem Cell Collection: Factors Influencing the Recovery of Granulocyte-Macrophage Colony Forming Cells

We evaluated data from all blood cell (BC) collections performed in our institution between 1989 and 1995 to determine factors influencing the outcome of collection. One hundred and thirty-three collections were performed on 106 patients. Malignant diagnoses were: non-Hodgkins lymphoma (NHL) in 35%, multiple myeloma in 31%, breast cancer in 26%, and Hodgkin's disease in 8%. Collections were obtained routinely in myeloma and breast cancer and due to bone marrow involvement with malignancy or inaspirable bone marrow in lymphoma patients. Collections were obtained on a Cobe Spectra or Baxter-Fenwall CS3000+. Engraftment potential was determined by methylcellulose colony assay (CFU-GM), with a target of >10 × 104 CFU-GM/kg. Apheresis nucleated cell count correlated significantly, albeit weakly (r = 0.26), with CFU-GM with a cell count of >5 × 10s/kg resulting in an adequate number of CFU-GM in 78% of patients. In univariant analysis outcome of collection was significantly influenced by the patients age (p = 0.01), malignant diagnosis (p < 0.001), reason for collection (p = 0.002), and the mobilization regimen (p = 0.01). The nature of the apheresis device used did not influence outcome. Only malignant diagnosis was significant (p < 0.001) in multivariate analysis. We conclude that the outcome of BC is most strongly influenced by patient factors such as malignant diagnosis. These factors must be considered when comparing the outcome of different mobilization regimens and when planning collection strategies.

Timing of Cord Blood Treatment after Experimental Stroke Determines Therapeutic Efficacy

Embolic stroke is thought to cause irreparable damage in the brain immediately adjacent to the region of reduced blood perfusion. Therefore, much of the current research focuses on treatments such as anti-inflammatory, neuroprotective, and cell replacement strategies to minimize behavioral and physiological consequences. In the present study, intravenous delivery of human umbilical cord blood cells (HUCBC) 48 h after a middle cerebral artery occlusion (MCAo) in a rat resulted in both behavioral and physiological recovery. Nissl and TUNEL staining demonstrated that many of the neurons in the core were rescued, indicating that while both necrotic and apoptotic cell death occur in ischemia, it is clear that apoptosis plays a larger role than first anticipated. Further, immunohistochemical and histochemical analysis showed a diminished and/or lack of granulocyte and monocyte infiltration and astrocytic and microglial activation in the parenchyma in animals treated with HUCBC 48 h poststroke. Successful treatment at this time point should offer encouragement to clinicians that a therapy with a broader window of efficacy may soon be available to treat stroke.

Myeloid progenitor cluster formation drives emergency and leukaemic myelopoiesis

Although many aspects of blood production are well understood, the spatial organization of myeloid differentiation in the bone marrow remains unknown. Here we use imaging to track granulocyte/macrophage progenitor (GMP) behaviour in mice during emergency and leukaemic myelopoiesis. In the steady state, we find individual GMPs scattered throughout the bone marrow. During regeneration, we observe expanding GMP patches forming defined GMP clusters, which, in turn, locally differentiate into granulocytes. The timed release of important bone marrow niche signals (SCF, IL-1β, G-CSF, TGFβ and CXCL4) and activation of an inducible Irf8 and β-catenin progenitor self-renewal network control the transient formation of regenerating GMP clusters. In leukaemia, we show that GMP clusters are constantly produced owing to persistent activation of the self-renewal network and a lack of termination cytokines that normally restore haematopoietic stem-cell quiescence. Our results uncover a previously unrecognized dynamic behaviour of GMPs in situ, which tunes emergency myelopoiesis and is hijacked in leukaemia.

[Activation of regeneration of red and white pulp of the spleen after the combined transplantation of HSC and MSCS in terms of exposure to ionizing radiation]

The purpose of this work was to study the effect of combined transplantation of multipotent mesenchymal stromal (MSCS) and hematopoietic stem cells (HSCs) isolated from the placenta, on the regeneration of white and red pulp of the spleen under physiological conditions and in conditions of exposure to ionizing radiation. Methods. The experiments were performed with laboratory mice-males. We studied the influence of ionizing radiation dose of 4.0 Gy. Animals of the experimental group were intravenously infused into MMSC and GSK respectively at a dose of 6 million cells/kg and 330 thousand cells/kg, suspended in 0.2 ml of 0.9% NaCl solution. The selection of hematopoietic stem cells was carried out using the direct technique of immune magnetic separation. Were studied the following morphometric parameters of the spleen: the average area of lymphoid follicles, the average area of zone of lymphoid follicles, average size of germinal center of lymphoid follicles, average size T-zones of lymphoid follicles, the average distance between the centers of the follicles, the average cellularity of the red pulp. Results. As a result, of research obtained that after exposure to ionizing radiation on the background of combined transplantation of HSC and MSCS there is an increase in size of lymphoid follicle at the expense of area B-zone of the follicle, the area germinative center of the follicle, restoring the content of lymphoblasts and lymphoblasts and lymphocytes to normal values. On the background of transplantation MMSC and GSK in terms of radiation exposure changes and the red pulp of the spleen. The increase in the density of cells in the red pulp of the spleen and, as a consequence, of the increase of the distance between the centers of lymphoid follicles. The increase in the density of cells in the red pulp occurs due to the increase in the content of erythroid cells and by increasing granulocytes. Key words: ionizing radiation, multipotent mesenchymal stromal cells, hematopoietic stem cells, spleen, regeneration. Conclusion. Studies have shown the effectiveness of combined transplantation MSC and GSK in respect of the main morphometric parameters of the spleen after exposure to ionizing radiation.

Morphometric and Densitometric Analysis of Heterochromatin during Cell Differentiation Using the Leukaemic Granulocytic Lineage as a Convenient Model

Granulocytic early progenitors and terminally differentiated - mature granulocytes with segmented nuclei were studied using computer-assisted diameter and heterochromatin optical image densitometry to provide more information on the nuclear size and heterochromatin condensation state. Bone marrow smears of patients suffering from chronic myeloid leukaemia untreated as well as treated with "specific" anti-leukaemic therapy with imatinib mesylate are a convenient model for such study because they possess a satisfactory number of cells for diameter and optical density measurements. In addition, the identification of developmental stages of granulocytes is very easy and the morphology is not different from that in not-leukaemic persons. As it was expected, the mean diameter of nuclear segments in fully differentiated and mature granulocytes was much smaller than that in non-segmented nuclei of early granulocytic precursors. Therefore, no wonder that the heterochromatin condensation state in nuclear segments of mature granulocytes was much larger than in non-segmented nuclei of granulocytic progenitors. On the other hand, the sum of mean diameters of all nuclear segments per cell was close to the mean nuclear diameter of early granulocytic progenitors. The heterochromatin condensation state in granulocytic progenitors or fully differentiated mature granulocytes exhibited marked stability and did not change after the anti-leukaemic therapy. In addition, Barr bodies of characteristic drumstick appearance bearing inactive X chromosome in interphase nuclei of mature granulocytes in fertile female patients exhibited a heterochromatin condensation state similar to nuclear segments. This heterochromatin condensation state was also stable and constant, and was not apparently influenced by the anti-leukaemic therapy.

A Rare Case of Adult Autoimmune Neutropenia Successfully Treated with Prednisolone

Autoimmune neutropenia (AIN) is a rare disorder that may cause life-threatening infections. In adults, most cases are secondary to other pathological conditions, and primary AIN is extremely rare. We herein report a case involving a 57-year-old woman diagnosed with AIN. A granulocyte immunofluorescence test detected autoantibodies against human neutrophil antigens in her serum, while various examinations revealed no other causes of neutropenia, suggesting her AIN was primary. She was refractory to granulocyte-colony-stimulating factor but responded to prednisolone. Her neutrophil count remained normal after gradual discontinuation of prednisolone. Diagnostic procedures and optimal treatments for this disorder need to be established.

Circulating Microvesicles Are Elevated Acutely following Major Burns Injury and Associated with Clinical Severity

Microvesicles are cell-derived signaling particles emerging as important mediators and biomarkers of systemic inflammation, but their production in severe burn injury patients has not been described. In this pilot investigation, we measured circulating microvesicle levels following severe burns, with severe sepsis patients as a comparator group. We hypothesized that levels of circulating vascular cell-derived microvesicles are elevated acutely following burns injury, mirroring clinical severity due to the early onset and prevalence of systemic inflammatory response syndrome (SIRS) in these patients. Blood samples were obtained from patients with moderate to severe thermal injury burns, with severe sepsis, and from healthy volunteers. Circulating microvesicles derived from total leukocytes, granulocytes, monocytes, and endothelial cells were quantified in plasma by flow cytometry. All circulating microvesicle subpopulations were elevated in burns patients on day of admission (day 0) compared to healthy volunteers (leukocyte-microvesicles: 3.5-fold, p = 0.005; granulocyte-microvesicles: 12.8-fold, p<0.0001; monocyte-microvesicles: 20.4-fold, p<0.0001; endothelial- microvesicles: 9.6-fold, p = 0.01), but decreased significantly by day 2. Microvesicle levels were increased with severe sepsis, but less consistently between patients. Leukocyte- and granulocyte-derived microvesicles on day 0 correlated with clinical assessment scores and were higher in burns ICU non-survivors compared to survivors (leukocyte MVs 4.6 fold, p = 0.002; granulocyte MVs 4.8 fold, p = 0.003). Mortality prediction analysis of area under receiver operating characteristic curve was 0.92 (p = 0.01) for total leukocyte microvesicles and 0.85 (p = 0.04) for granulocyte microvesicles. These findings demonstrate, for the first time, acute increases in circulating microvesicles following burns injury in patients and point to their potential role in propagation of sterile SIRS-related pathophysiology.

[The characteristics of the new indices of hemogram under liver cirrhosis]

The diagnostic significance of new indices of hemogram under liver cirrhosis associated with thrombocytopenia (n=64) was analyzed. It is established that in comparison with control group the patients with cirrhosis are characterized by statistically valuable increasing of content of immature cells of three germs of hematopoiesis: reticulocytes up to 1.99±1.54%, granulocytes up to 0.44±0.77%, immature thrombocytes up to 3.23±1.7%. Under liver pathology, the following occurrences are detected: "left shift" of reticulocyte and leukocyte formula; reliable decreasing of content of hemoglobin in reticulocytes. The increasing of both of content of fragmentary erythrocytes (Frg) up to 0.83±1.21% and level of delta-hemoglobin (D-He>4 ng) were interpreted as additional markers of hemolysis. At that, negative values of delta-hemoglobin (D-He<0 ng) in 6.3% of patients are associated with concomitant inflammation. As a result of study, new data was obtained concerning characteristics of hematopoiesis under liver cirrhosis increasing quality of laboratory monitoring of patients with the given pathology.

Reduction of c-Fos via Overexpression of miR-34a Results in Enhancement of TNF- Production by LPS in Neutrophils from Myelodysplastic Syndrome Patients

Although increased TNF-α has been considered to cause ineffective hematopoiesis in myelodysplastic syndromes (MDS), the mechanisms of TNF-α elevation are not known. We recently found that c-Fos mRNA stabilization under translation-inhibiting stimuli was impaired in MDS-derived neutrophilic granulocytes. In the current study, we identified overexpression of c-Fos-targeting miR-34a and miR-155 as the cause of impairment. Expression levels of miR-34a but not miR-155 inversely correlated with ratios of c-Fos-positive cells in MDS-derived CD16⁺ neutrophils (r = -0.618, P<0.05), which were analyzed by flow cytometry. Among the seventeen patients, c-Fos was detectable in less than 60% of CD16⁺ cells in eight patients (Group A), while five (Group B) expressed c-Fos in more than 80% of CD16⁺ cells, which was consistent with the controls (88.6 ± 7.8%). Group A-derived granulocytes secreted more TNF-α in response to 1 μM LPS for 3 hours (735.4 ± 237.5 pg/mL) than Group B (143.5 ± 65.7 pg/mL, P<0.05) and healthy controls (150.8 ± 91.5 pg/mL, P<0.05). Knockdown of c-Fos in neutrophil-like differentiated HL60 increased the binding of NF-κB p65 to the promoter region of TNF-α DNA. Thus, c-Fos reduction via overexpression of miR-34a contributes to TNF-α overproduction under inflammatory stimuli in MDS.