Bone Marrow Granulocyte Research Articles

Associated factors and prognostic implications of neutropenia in individuals with HIV/AIDS

BackgroundNeutropenia frequently presents as a hematological manifestation among people living with HIV/AIDS (PLWHA). This study explores the factors associated with neutropenia in PLWHA and its prognostic significance.MethodsWe conducted a retrospective case-control study of the clinical data from 780 cases of individuals living with HIV/AIDS, who were admitted to Zhongnan Hospital of Wuhan University over the period from January 2016 to September 2020. We categorized the patients into two different groups based on absolute neutrophil Count (ANC): neutropenia group (ANC < 2.0 × 109/L, 33.7%) and non-neutropenia group (ANC ≥ 2.0 × 109/L, 66.3%). We analyzed the co-infections, blood routine test, infection indicators, lymphocyte subpopulation, bone marrow cell cytology, bone marrow morphology in both groups. Additionally, we analyzed the prognosis of the patients.ResultsThe results of multifactorial logistic regression showed that increased C-reactive protein (CRP) (p<0.001, adjusted odds ratio [AOR] = 0.984, 95% CI:0.975–0.993), Monocyte (MONO) (p = 0.011, AOR = 0.091, 95% CI: 0.013–0.637), CD19+B lymphocytes (p = 0.008, AOR = 0.990, 95% CI: 0.983–0.997), Bone marrow granulocyte (p = 0.017, AOR = 0.936, 95% CI: 0.883–0.992) were protective factors for neutropenia in PLWHA. Kaplan–Meier survival curve analysis showed that Grade 2 neutropenia group (ANC<0.5 × 109/L) had a worse prognosis than Grade 1 neutropenia group (0.5 × 109/L ≤ ANC<2 × 109/L, p = 0.019) and non-neutropenia group (ANC ≥ 2.0 × 109/L, p = 0.008). Older age (p = 0.002), lower hemoglobin levels (p = 0.001), and a reduced proportion of bone marrow granulocytes (p = 0.002) were associated with a poorer prognosis in PLWHA.ConclusionHIV infection can lead to reduced neutrophil counts and damage to the immune system through multiple pathways. Severe neutropenia results in a worse prognosis, making timely diagnosis and treatment of neutropenia in this population essential.

Bipotential B-neutrophil progenitors are present in human and mouse bone marrow and emerge in the periphery upon stress hematopoiesis.

This study investigates the dynamics of hematopoiesis in COVID-19, focusing on neutrophil responses. Through RNA sequencing of neutrophils from healthy controls and COVID-19 patients, distinct gene expression alterations are identified, particularly in ICU patients. Notably, neutrophils from COVID-19 patients, especially in the ICU, exhibit enrichment of immunoglobulin and B cell lineage-associated genes, suggesting potential lineage plasticity. Validation in a larger patient cohort and single-cell analysis of bone marrow granulocytes support the presence of granulocyte-monocyte progenitors with B cell lineage-associated genes. The findings propose a link between B-neutrophil lineages during severe infection, implicating a potential role for these cells in altered hematopoiesis favoring myeloid cells over B cells. Elevated GM-CSF and reduced IL-7 receptor expression in stress hematopoiesis suggest cytokine involvement in these dynamics, providing novel insights into disease pathogenesis.

Immunophenotype of myeloid granulocytes in Chinese patients with BCR::ABL1-negative myeloproliferative neoplasms

Typical BCR::ABL1-negative myeloproliferative neoplasms (MPN) are mainly referred to as polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofbrosis (PMF). Granulocytes in MPN patients are involved in their inflammation and form an important part of the pathophysiology of MPN patients. It has been shown that the immunophenotype of granulocytes in MPN patients is altered. We used flow cytometry to explore the immunophenotype of MPN patients and correlate it with clinical parameters. The results showed that PMF patients and PV patients had higher CD15+CD11b+ granulocytes than ET patients and normal controls. When grouped by gene mutation, changes in the granulocyte immunophenotype of MPN patients were independent of the JAK2V617F and CALR mutations. There was no significant heterogeneity in immunophenotype between ET patients and Pre-PMF, and between Overt-PMF and Pre-PMF patients. Granulocytes from some MPN patients showed an abnormal CD13/CD16 phenotype with a significant increase in mature granulocytes on molecular and cytomorphological grounds, and this abnormal pattern occurred significantly more frequently in PMF patients than in ET patients. CD15–CD11b– was negatively correlated with WBC and Hb and positively correlated with DIPSS score, whereas high CD10+ granulocytes were significantly and negatively associated with prognostic system IPSS and DIPSS scores in PMF patients. In conclusion, this study demonstrates the landscape of bone marrow granulocyte immunophenotypes in MPN patients. MPN patients, especially those with PMF, have a significant granulocyte developmental overmaturation phenotype. CD10+ granulocytes may be involved in the prognosis of PMF patients.

Efficacy of Reducing Recurrence of Intrauterine Adhesions and Improving Pregnancy Outcome after Hysteroscopic Adhesiolysis: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

Background: A systematic review with pairwise and network meta-analyses was conducted to compare the clinical efficacy of treatments in reducing intrauterine adhesion (IUA) recurrence and improving pregnancy outcome after hysteroscopic adhesiolysis. Methods: PubMed, Web of Science, Embase, Cochrane library, and Clinicaltrials.gov were searched electronically up to January 17th, 2024, supplemented with manual searches. Eligible studies were randomized clinical trials (RCTs) with allocation to intrauterine device (IUD), auto-cross-linked hyaluronic acid (ACP), medical chitosan (MC) + IUD, Foley (Foley balloon catheter 3–7 days) + IUD, heart shape balloon (HSB), dried amnion graft or bone marrow stem cells-scaffold or granulocyte colony-stimulating factor (DBG) + Foley/HSB, autologous platelet gel or platelet-rich plasma (APG/PRP) + IUD/HSB, ACP + Foley/IUD, Foley, and heart shape balloon or Foley 1 month (H/F) + IUD. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Pairwise meta-analyses were performed in random effects model when direct data were available; Network meta-analyses were conducted using “mvmeta” and “network” packages in Stata MP 17.0. The primary outcomes were the recurrence of IUA and clinical pregnancy. The secondary outcomes included menstrual blood volume and second-look IUA score. The research protocol was registered in PROSPERO (CRD42024502941). Results: Fifteen RCTs comprising 1827 patients randomized to ten treatment protocols were included in this study. Evidence quality was all low risk of bias. ACP and Foley + IUD (surface under the cumulative ranking curve area (SUCRA) 96.4% and 83.5%, respectively) seemed effective in reducing the recurrence of IUA, H/F + IUD and DBG + Foley/HSB (SUCRA 89.7% and 82.1%, respectively) maybe effective in improving the clinical pregnancy according to network meta-analysis. Evidence on secondary treatment outcomes was insufficient. Conclusions: Some of these protocols maybe effective in reducing the recurrence of IUA or increasing clinical pregnancy. But the result should be interpreted with caution owing to the small studies, open-loop network analysis partly, and insufficient evidence. More RCTs about DBG + Foley/HSB needs to be designed, the relative effectiveness of different degrees of IUA treatment should be further clarified, and more attention should be paid to clinical pregnancy, menstrual flow, and second-look IUA score.

Chronic neutrophilic leukemia and atypical chronic myeloid leukemia: 2024 update on diagnosis, genetics, risk stratification, and management.

Chronic neutrophilic leukemia (CNL) is a rare BCR::ABL1-negative myeloproliferative neoplasm (MPN) defined by persistent mature neutrophilic leukocytosis and bone marrow granulocyte hyperplasia. Atypical chronic myeloid leukemia (aCML) (myelodysplastic "[MDS]/MPN with neutrophilia" per World Health Organization [WHO]) is a MDS/MPN overlap disorder featuring dysplastic neutrophilia and circulating myeloid precursors. Both manifest with frequent hepatosplenomegaly and less commonly, bleeding, with high rates of leukemic transformation and death. The 2022 revised WHO classification conserved CNL diagnostic criteria of leukocytosis ≥25 × 109/L, neutrophils ≥80% with <10% circulating precursors, absence of dysplasia, and presence of an activating CSF3R mutation. ICC criteria are harmonized with those of other myeloid entities, with a key distinction being lower leukocytosis threshold (≥13 × 109/L) for cases CSF3R-mutated. Criteria for aCML include leukocytosis ≥13 × 109/L, dysgranulopoiesis, circulating myeloid precursors ≥10%, and at least one cytopenia for MDS-thresholds (ICC). In both classifications ASXL1 and SETBP1 (ICC), or SETBP1 ± ETNK1 (WHO) mutations can be used to support the diagnosis. Both diseases show hypercellular bone marrow due to a granulocytic proliferation, aCML distinguished by dysplasia in granulocytes ± other lineages. Absence of monocytosis, rare/no basophilia, or eosinophilia, <20% blasts, and exclusion of other MPN, MDS/MPN, and tyrosine kinase fusions, are mandated. Cytogenetic abnormalities are identified in ~1/3 of CNL and ~15-40% of aCML patients. The molecular signature of CNL is a driver mutation in colony-stimulating factor 3 receptor-classically T618I, documented in >80% of cases. Atypical CML harbors a complex genomic backdrop with high rates of recurrent somatic mutations in ASXL1, SETBP1, TET2, SRSF2, EZH2, and less frequently in ETNK1. Leukemic transformation rates are ~10-25% and 30-40% for CNL and aCML, respectively. Overall survival is poor: 15-31 months in CNL and 12-20 months in aCML. The Mayo Clinic CNL risk model for survival stratifies patients according to platelets <160 × 109/L (2 points), leukocytes >60 × 109/L (1 point), and ASXL1 mutation (1 point); distinguishing low- (0-1 points) versus high-risk (2-4 points) categories. The Mayo Clinic aCML risk model attributes 1 point each for: age >67 years, hemoglobin <10 g/dL, and TET2 mutation, delineating low- (0-1 risk factor) and high-risk (≥2 risk factors) subgroups. Management is risk-driven and symptom-directed, with no current standard of care. Most commonly used agents include hydroxyurea, interferon, Janus kinase inhibitors, and hypomethylating agents, though none are disease-modifying. Hematopoietic stem cell transplant is the only potentially curative modality and should be considered in eligible patients. Recent genetic profiling has disclosed CBL, CEBPA, EZH2, NRAS, TET2, and U2AF1 to represent high-risk mutations in both entities. Actionable mutations (NRAS/KRAS, ETNK1) have also been identified, supporting novel agents targeting involved pathways. Preclinical and clinical studies evaluating new drugs (e.g., fedratinib, phase 2) and combinations are detailed.

Modern management of leukemoid reactions

ABSTRACT. Leukemoid reaction (LR) is a transient hematological syndrome of reactive nature characterized by persistent leukocytosis of more than 50,000 cells/µL. LR can be caused by a variety of factors, including infections, intoxications, malignant neoplasms, severe hemorrhages, or acute hemolysis.&#x0D; The most common form of LR is neutrophilic myeloid reaction, which occurs in 80-90 % of cases. The diagnosis of LR is based on clinical examination and laboratory test results, including complete blood count with differential leukocyte formula, determination of leukocyte alkaline phosphatase level, aspiration and biopsy of bone marrow.&#x0D; Differential diagnosis of LR from other forms of leukemia is a challenging task. For this, it is necessary to conduct a thorough examination, including cytogenetic and molecular analysis of peripheral blood and bone marrow granulocytes. Despite certain advances in the differential diagnosis of LR, the mortality rate of patients in the world remains high, which requires the attention of doctors of various profiles.&#x0D; Treatment of LR depends on the underlying cause that caused it. The article proposes a diagnostic and treatment algorithm for LR in the case of its toxico-infectious origin.

Changed regulation of granulocyte NADPH oxidase activity in the mouse model of obesity-induced type 2 diabetes mellitus

NADPH oxidase is a target of hyperglycemia in type 2 diabetes mellitus (T2DM), which causes dysregulation of enzyme. Alterations in regulation of NADPH oxidase activity mediated receptor and non-receptor signaling in bone marrow granulocytes of mice with obesity-induced T2DM were studied. The animals fed high fat diet (516 kcal/100 g) for 16 weeks. NADPH oxidase-related generation of reactive species (RS) at normo- and hyperthermia was estimated using chemiluminescent analysis. The redox status of the cells was assessed by Redox Sensor Red CC-1. Baseline biochemical indicators in blood (glucose, cholesterol, HDL and LDL levels) were significant higher in T2DM mice versus controls. Using specific inhibitors, signaling mediated by formyl peptide receptors (FPRs) to NADPH oxidase was shown to involve PLC, PKC, cytochrome p450 in both control and T2DM groups and PLA2 in controls. In T2DM regulation of NADPH oxidase activity via mFpr1, a high-affinity receptors, occurred with a significant increase of the role of PKC isoforms and suppression of PLA2 participation. Significant differences between this regulation via mFpr2, low-affinity receptors, were not found. Non-receptor activation of NADPH oxidase with ionomycin (Ca2+ ionophore) or phorbol ester (direct activator of PKC isoforms) did not revealed differences in the kinetic parameters between groups at 37 °C and 40 °C. When these agents were used together (synergistic effect), lower sensitivity of cells to ionophore was observed in T2DM at both temperatures. Redox status in responses to opsonized zymosan was higher in T2DM mice at 37 °C and similar to control levels at 40 °C. ROC-analysis identified Tmax, RS production and effect of opsonized zymosan as the most significant predictors for discriminating between groups. It was concluded that Ca2+-dependent/PKC-mediated regulation of NADPH oxidase activity was altered in BM granulocytes from diabetic mice.

The Effect of Nicotine Acetylcholine Receptor Ligands on the Adhesive Properties of Murine Bone Marrow Granulocytes in Inflammation

The Effect of Nicotine Acetylcholine Receptor Ligands on the Adhesive Properties of Murine Bone Marrow Granulocytes in Inflammation

Identification of rat Vstm1 with conservative anti-inflammatory effect between rat and human homologs

Human VSTM1 (also known as SIRL1) is an inhibitory immune checkpoint receptor involved in leukocyte activation. Identification of the homologous genes in other species, such as mice and rats, will undoubtedly contribute to functional studies and clinical applications. Here, we successfully cloned the Vstm1 gene in rats, as supported by high-throughput sequencing data. However, Vstm1 is degenerated to a pseudogene in the mouse genome. Rat Vstm1 mRNA contains a complete open reading frame (ORF) of 630 nucleotides encoding 209 amino acids. Rat Vstm1 is highly expressed in bone marrow, especially in granulocytes. The expression levels of Vstm1 gradually increase with the development of granulocytes in bone marrow but are downregulated in response to inflammatory stimuli. Rat VSTM1 does not have an immunoreceptor tyrosine-based inhibitory motif (ITIM), however, it shows a conservative function of inflammatory inhibition with human VSTM1, and both are anti-correlated with many inflammatory cytokines, such as IL-1α and TNF-α. In bone marrow-derived macrophages (BMDMs), either rat or human VSTM1 suppressed the secretion of inflammatory cytokines in response to LPS stimulation. Further analysis in lung cancer microenvironment revealed that VSTM1 is mainly expressed in myeloid cells, anti-correlated with inflammatory cytokines and associated with tumor development and metastasis.

Phase I Trial of Allogeneic Donor Gamma Delta T Cell Infusion Post-Hematopoietic Cell Transplantation, an Interim Safety Report

Background Patients with 2017 European LeukemiaNet (ELN) adverse risk acute myeloid leukemia (AML) are at 40% risk of relapse leading to poor survival after allogeneic hematopoietic cell transplantation (allo-HCT) (Hansen TCT 2021, Jimenez BMT 2021). Ex vivo donor-derived gamma delta T cells (GDT) expanded with artificial antigen presented calls (aAPC) are a novel therapy with potent MHC-independent antineoplastic cytotoxicity. An ongoing phase 1/1b study is evaluating the safety and potential efficacy of ex vivo expanded donor GDT after reduced-intensity conditioning (RIC) allo-HCT in patients with ELN adverse risk AML ( NCT05015426). We report on manufacturing, safety, and correlative biology of expanded donor GDT after allo-HCT in the first 5 treated patients (Table 1). Methods The primary endpoint is the maximum-tolerated dose (MTD) of allogeneic donor GDT as a single infusion at day 60 after RIC allo-HCT. Next generation sequencing was used for measurable residual disease (MRD) assessment pre-HCT and post-GDT infusion. Donor GDT collected from the same donor of the allo-HCT were enriched from non-mobilized leukapheresis product by stimulation with zoledronic acid and IL-2 for 7 days followed by alpha beta T cell depletion using the Miltenyi CliniMACS. Enriched GDT (&amp;gt;90% TCRVδ2) were then co-cultured with irradiated aAPCs in Wilson Wolf G-Rex 100MCS over 10 days (Boucher J. Immunother 2023). This single center, investigator-initiated phase 1 trial is testing 3 distinct dose cohorts of infused GDT (5 x 10 6 cells/kg, 2.5 x 10 7 cells/kg, and 1 x 10 8 cells/kg) with acceptable range of 25% margin. A Bayesian optimal interval design is used to guide dose escalation/de-escalation decisions. Results First 3 patients enrolled in dose level 1 (DL1) cohort received GDT dose of 6.25 x 10 6 cells/kg, while last 2 patients enrolled in DL2 cohort received 3.13 x 10 7 cells/kg dose. Dose-limiting toxicities (DLT) were evaluated for 42 days following GDT infusion and no DLT were observed. None of the treated patients experienced cytokine release syndrome (CRS), Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS) or graft-versus-host disease (GVHD) during DLT period. Among patients treated on DL1, patient #01 had ASXL1 AML with MRD pos (VAF 43.9%) prior to RIC haploidentical (Haplo) HCT. He is in ongoing complete remission (CR) 9 months post-HCT and has had no GVHD. Patient #02 had MRD pos (VAF 61.7%) AML with TP53 mutation/complex karyotype prior to RIC matched sibling donor allo-HCT. He is in CR and has mild chronic GVHD at 7 months post-HCT. Patient #03 with pre-HCT MRD negRUNX1 AML is in ongoing CR 7 months post-RIC Haplo HCT with no GVHD. At day 28 and day 120 post-GDT, all 3 patients were MRD neg in bone marrow and had 100% bone marrow and peripheral blood leukocyte and granulocyte chimerism. In DL2 cohort, patient #04 with RUNX1 AML and patient #05 with t(9;22) AML both were MRD neg prior to RIC Haplo HCT and remain in CR with no GVHD at 5 and 4 months post-HCT, respectively. At day 28 post-GDT, both patients were MRD neg and had 100% chimerism. Patient #05 had a fall during DLT period in a setting of orthostatic hypotension requiring hospitalization for 24 hours for hydration. This was the only grade 3 adverse event observed in this trial. Serum cytokines analyzed included IL2, IL6, IL15, IFNγ, TNFα, Angiopoietin 1&amp;2, and GM-CSF (Figure 1). We compared results prior and up to 90 days post-GDT infusion and found no significant differences, which can explain no CRS or ICANS events yet observed on this trial. Immunophenotype (TCRVδ2, TCRVδ1, PD1, CTLA4, TIGIT and CD28) of GDT was analyzed in samples of donor apheresis, pre- and post-enrichment, infused GDT product and at days 28 and 90 post-infusion. GDT (TCRVδ2) persisted at day 28 and day 90 post-infusion and expressed low levels of cell surface inhibitory receptors. Conclusion This preliminary interim report demonstrates favorable safety and tolerability of donor GDT therapy with no CRS, ICANS or GVHD in first 5 patients treated in this trial. All these patients with adverse risk AML are in ongoing MRD neg CR following RIC allo-HCT, including 2 pre-HCT MRD pos cases with TP53 AML and AXSL1 AML. Early results of this trial are promising, which provides validation for continued testing of adoptive transfer of ex vivo expanded donor GDT. Updated results of this trial will be presented at the annual conference.

Modified Signaling of Membrane Formyl Peptide Receptors in NADPH-Oxidase Regulation in Obesity-Resistant Mice.

The signaling of membrane receptors is modified in obesity characterized by low-grade inflammation. The obesity-resistant state of organisms is poorly understood. We analyzed the generation of reactive oxygen species (ROS) initiated though membrane formyl peptide receptors (Fpr1, Fpr2) in bone-marrow granulocytes of obesity-resistant mice (ORM). A chemiluminescence assay was used to assess NADPH-oxidase-related intensity of ROS generation. ORM were chosen from animals that received high-fat diets and had metric body parameters as controls (standard diet). High spontaneous ROS production was observed in ORM cells. The EC50 for responses to bacterial or mitochondrial peptide N-formyl-MLF was higher in ORM with and without inflammation vs. the same control groups, indicating an insignificant role of high-affinity Fpr1. Increased responses to synthetic peptide WKYMVM (Fpr2 agonist) were observed in controls with acute inflammation, but they were similar in other groups. Fpr2 was possibly partially inactivated in ORM owing to the inflammatory state. Weakened Fpr1 and Fpr2 signaling via MAPKs was revealed in ORM using specific inhibitors for p38, ERK1/2, and JNK. P38 signaling via Fpr2 was lower in ORM with inflammation. Thus, a high-fat diet modified FPRs' role and suppressed MAPK signaling in NADPH-oxidase regulation in ORM. This result can be useful to understand the immunological features of obesity resistance.

The role of CSE1L silencing in the regulation of proliferation and apoptosis via the AMPK/mTOR signaling pathway in chronic myeloid leukemia

ABSTRACTObjectivesChromosome segregation 1-like (CSE1L) is abundant and strongly expressed in solid tumors. However, the expression and role of CSE1L in chronic myeloid leukemia(CML) remain largely unknown.Materials and methodsThe relative expression levels of CSE1L in bone marrow granulocytes from patients with primary CML and non-hematologic controls were measured by flow cytometry. Cell counting kit-8 analysis, DNA Content Quantitation Assay, and Annexin V-PE/7-AAD staining were applied to assess the effects of CSE1L knockdown on cell proliferation, cell cycle progression, and apoptosis.ResultsElevated expression of CSE1L was detected in bone marrow granulocytes of patients with primary CML. In the CML cell line K562 cells, CSE1L knockdown impaired cell proliferation blocked the cell cycle shift from G0/G1 phase to the S phase, and promoted apoptosis. Knockdown of CSE1L reduced Bcl-2 protein expression and increased Bax protein expression. Meanwhile, knockdown of CSE1L enhanced the expression of phospho-AMPK protein and decreased the expression of phospho-mTOR protein. The expression of total AMPK and mTOR proteins was not affected. In addition, CSE1L expression levels were decreased in imatinib-treated K562 cells.ConclusionsCSE1L plays a pivotal role in K562 cell survival and growth. These functions may be partially dependent on the AMPK/mTOR signaling pathway to achieve. In addition, CSE1L may have had a future impact on the treatment of CML patients.

Selenium Nanoparticles Can Influence the Immune Response Due to Interactions with Antibodies and Modulation of the Physiological State of Granulocytes.

Currently, selenium nanoparticles (SeNPs) are considered potential immunomodulatory agents and as targets for activity modulation are granulocytes, which have the most abundant population of immune blood cells. The present study aims to evaluate the cytotoxic effect and its effect on the functional responses of granulocytes. In addition to the intrinsic activity of SeNPs, we studied the activity of the combination of SeNPs and IgG antibodies. Using laser ablation and fragmentation, we obtained nanoparticles with an average size of 100 nm and a rather narrow size evolution. The resulting nanoparticles do not show acute toxicity to primary cultures of fibroblasts and hepatocytes, epithelial-like cell line L-929 and granulocyte-like culture of HL-60 at a concentration of 109 NPs/mL. SeNPs at a concentration of 1010 NPs/mL reduced the viability of HL-60 cells by no more than 10% and did not affect the viability of the primary culture of mouse granulocytes, and did not have a genotoxic effect on progenitor cells. The addition of SeNPs can affect the production of reactive oxygen species (ROS) by mouse bone marrow granulocytes, modulate the proportion of granulocytes with calcium spikes and enhance fMLF-induced granulocytes degranulation. SeNPs can modulate the effect of IgG on the physiological responses of granulocytes. We studied the expression level of genes associated with inflammation and cell stress. SeNPs increase the expression of catalase, NF-κB, Xrcc5 and some others; antibodies enhance the effect of SeNPs, but IgG without SeNPs decreases the expression level of these genes. This fact can be explained by the interaction between SeNPs and IgG. It has been established that antibodies interact with SeNPs. We showed that antibodies bind to the surface of selenium nanoparticles and are present in aqueous solutions in a bound form from DLS methods, ultraviolet-visible spectroscopy, vibrational-rotational spectrometry, fluorescence spectrometry, and refractometry. At the same time, in a significant part of the antibodies, a partial change in the tertiary and secondary structure is observed. The data obtained will allow a better understanding of the principles of the interaction of immune cells with antibodies and SeNPs and, in the future, may serve to create a new generation of immunomodulators.

Correlations between glucose metabolism of bone marrow on 18 F-fluoro-D-glucose PET/computed tomography and hematopoietic cell populations in autoimmune diseases.

This study aims to investigate which hematopoieticcell populations, clinical factors, and laboratory values are associated with FDG uptake in bone marrow (BM) on FDG PET/CT in patients with autoimmune diseases. Forty-six patients with autoimmune disease who underwent FDG PET/CT and BM aspiration (BMA) between 2017 and 2022 were enrolled. The max and mean standard uptake values (SUVmax and SUVmean, SUVs) of FDG in BM, liver, and spleen were measured, and the bone marrow-to-liver SUVs ratios (BLRmax and BLRmean, BLRs) and spleen-to-liver SUVs ratios (SLRmax and SLRmean, SLRs) were calculated. BMA and clinical and laboratory parameters were collected and evaluated for association with BLRs and SLRs. The patients were divided into the Grade II group (20; 43.5%) and Grade III groups (26; 56.5%) according to hemopoietic activity. The BLRmax ( P = 0.021), proportion of granulocytes ( P = 0.011), metamyelocytes ( P = 0.009), myelocytes ( P = 0.024), and monocytes ( P = 0.037) in BM were significantly higher in the Grade II group. Multivariate (stepwise) linear regression analyses showed that the proportion of granulocytes in BM was the strongest and only independent factor ( P < 0.0001) associated with BLRmax with an adjusted R2 of 0.431 in model 1. In model 2, ferritin ( P = 0.018), CRP ( P = 0.025), and the proportion of metamyelocytes ( P = 0.043) in BM were correlated with BLRmax with an adjusted R2 of 0.414. The FDG uptake in BM is associated with hemopoietic activity and is regulated by hyperplastic granulocytes, particularly immature metamyelocytes, in patients with autoimmune diseases. Glucose metabolism in the BM correlates with the severity of systemic inflammation.

Mechanisms of ERK phosphorylation triggered via mouse formyl peptide receptor 2

Formyl peptide receptors (FPRs) are expressed in the cells of the innate immune system and provide binding with pathogen and damage-associated molecular patterns with subsequent activation of the phagocytes for defense reactions such as chemotaxis, secretory degranulation and ROS generation. Probably, FPR2 is one of the unique receptors in the organism; it is able to recognize numerous ligands of different chemical structure, and moreover, these ligands can trigger opposite phagocyte responses promoting either pro- or anti-inflammatory reactions. Therefore, FPR2 and its signaling pathways are of intense research interest.We found only slight activation of ERK1/2 in the response to peptide ligand WKYMVM in the accelerating phase of ROS generation and more intense ERK1/2 phosphorylation in the declining phase of it in mouse bone marrow granulocytes. Lipid agonist BML-111 did not induce significant ERK phosphorylation when applied for 10–1800 s.To some extent co-localization of ERK1/2 and NADPH oxidase subunits was observed even in the intact cells and didn't change under FPR2 stimulation by WKYMVM, while direct PKC activation by PMA resulted to more efficient interaction between ERK1/2 and p47phox/p67phox and their translocation to plasma membrane. We have shown that phosphorylation and activation of ERK1/2 in bone marrow granulocytes depended on FPR2-triggered activity of PI3K and PKC, phosphatase DUSP6, and, the most but not the least, on ROS generation. Since blocking of ROS generation led to a slowdown of ERK activation indicating a significant contribution of ROS to the secondary regulation of ERK activity.

Effect of concomitant use of G-CSF and myelosuppressive chemotherapy on bone marrow and peripheral granulocytes in a mouse model.

Granulocyte-colony stimulating factor (G-CSF) stimulates bone marrow progenitor cell proliferation and enhances neutrophil production. Exogenous G-CSF administration is indicated for chemotherapy-induced neutropenia management. However, there is a paucity of basic research examining the effects of the concomitant use of G-CSF and chemotherapy on myeloid cells in vivo. Whether concomitant G-CSF and chemotherapy adversely affect myeloid cell proliferation have not been determined. Herein, we examined the effects of the concomitant use of pegfilgrastim and 5-fluorouracil on myeloid cells and peripheral blood cells in mouse models. Balb/c mice were treated intraperitoneally with 5-fluorouracil (20μg/g b.w.) or a vehicle as a control for 5days, and pegfilgrastim was administered subcutaneously at 1μg/g b.w. on day 3. As a result, we demonstrated that the concomitant use of pegfilgrastim suppressed the 5-fluorouracil-induced decrease of granulocytic cells in both bone marrow and peripheral blood in mice. To assess the clinical efficacy of early administration of pegfilgrastim during docetaxel, cisplatin, and 5-fluorouracil therapy in patients with esophageal cancer, we retrospectively identified 42 consecutive patients treated with this regimen. The incidence of both febrile neutropenia and grade 4 neutropenia was significantly lower in patients who received pegfilgrastim than in those who did not receive it (P = 0.002 and P = 0.002, respectively). These results suggest that the concomitant use of pegfilgrastim and chemotherapy, consisting of continuous infusions of 5-fluorouracil, improved chemotherapy-induced neutropenia without detrimental effects on proliferating myeloid granulocytic cells.

Bone marrow granulocytes downregulate IL-1β and TNF production and the microbicidal activity of inflammatory macrophages.

Macrophages play critical roles in inflammation and defense against pathogens, as well as in the return to tissue homeostasis. Macrophage subpopulations displaying antagonistic phenotypes are generally classified as proinflammatory M1, implicated in antipathogen and antitumoral activities, or as anti-inflammatory M2, associated with tissue repair. Granulocytic and monocytic myeloid-derived suppressor cells recruited from the bone marrow to tissues and phagocytosis of apoptotic neutrophils can attenuate macrophage microbicidal activity. Here, we showed that bone marrow neutrophils, but not thioglycollate-recruited neutrophils, directly suppress the responses of macrophages that were previously committed to an inflammatory phenotype. Cocultures of inflammatory macrophages with bone marrow CD11b+Ly6Ghi granulocytes led to reduced release of IL-1β, TNF-α, and IL-6 by macrophages after lipopolysaccharide stimulation. The suppressive activity was unrelated to granulocyte apoptosis or to secreted factors and required cell-to-cell contact. The suppressive effect was paralleled by reduction in the nuclear levels of the NF-κB p65 subunit, but not of the p50 subunit. Furthermore, bone marrow granulocytes decreased the phagocytic activity of macrophages and their capacity to kill intracellular Escherichia coli. Taken together, these results show that bone marrow granulocytes can function as suppressors of the proinflammatory activity and microbial-killing responses of macrophages.

Chronic neutrophilic leukemia: 2022 update on diagnosis, genomic landscape, prognosis, and management

Chronic neutrophilic leukemia (CNL) is a rare, often aggressive myeloproliferative neoplasm (MPN) defined by persistent mature neutrophilic leukocytosis, bone marrow granulocyte hyperplasia, and frequent hepatosplenomegaly. The 2013 seminal discovery of oncogenic driver mutations in colony-stimulating factor 3 receptor (CSF3R) in the majority of patients with CNL not only established its molecular pathogenesis but provided a diagnostic biomarker and rationale for pharmacological targeting. In 2016, the World Health Organization (WHO) recognized activating CSF3R mutations as a central diagnostic feature of CNL. Other criteria include leukocytosis of ≥25 × 109 /L comprising >80% neutrophils with <10% circulating precursors and rare blasts, and absence of dysplasia or monocytosis, while not fulfilling criteria for other MPN. There is currently no standard of care for management of CNL, due in large part to the rarity of disease and dearth of formal clinical trials. Most commonly used therapeutic agents include conventional oral chemotherapy (e.g., hydroxyurea), interferon, and Janus kinase (JAK) inhibitors, while hematopoietic stem cell transplant remains the only potentially curative modality. Increasingly comprehensive genetic profiling in CNL, including new data on clonal evolution, has disclosed a complex genomic landscape with additional mutations and combinations thereof driving disease progression and drug resistance. Although accurate prognostic stratification and therapeutic decision-making remain challenging in CNL, emerging data on molecular biomarkers and the addition of newer agents, such as JAK inhibitors, to the therapeutic arsenal, are paving the way toward greater standardization and improvement of patient care.

A randomized phase 2 trial of azacitidine with or without durvalumab as first-line therapy for higher-risk myelodysplastic syndromes

AbstractAzacitidine-mediated hypomethylation promotes tumor cell immune recognition but may increase the expression of inhibitory immune checkpoint molecules. We conducted the first randomized phase 2 study of azacitidine plus the immune checkpoint inhibitor durvalumab vs azacitidine monotherapy as first-line treatment for higher-risk myelodysplastic syndromes (HR-MDS). In all, 84 patients received 75 mg/m2 subcutaneous azacitidine (days 1-7 every 4 weeks) combined with 1500 mg intravenous durvalumab on day 1 every 4 weeks (Arm A) for at least 6 cycles or 75 mg/m2 subcutaneous azacitidine alone (days 1-7 every 4 weeks) for at least 6 cycles (Arm B). After a median follow-up of 15.25 months, 8 patients in Arm A and 6 in Arm B remained on treatment. Patients in Arm A received a median of 7.9 treatment cycles and those in Arm B received a median of 7.0 treatment cycles with 73.7% and 65.9%, respectively, completing ≥4 cycles. The overall response rate (primary end point) was 61.9% in Arm A (26 of 42) and 47.6% in Arm B (20 of 42; P = .18), and median overall survival was 11.6 months (95% confidence interval, 9.5 months to not evaluable) vs 16.7 months (95% confidence interval, 9.8-23.5 months; P = .74). Durvalumab-related adverse events (AEs) were reported by 71.1% of patients; azacitidine-related AEs were reported by 82% (Arm A) and 81% (Arm B). Grade 3 or 4 hematologic AEs were reported in 89.5% (Arm A) vs 68.3% (Arm B) of patients. Patients with TP53 mutations tended to have a worse response than patients without these mutations. Azacitidine increased programmed cell death ligand 1 (PD-L1 [CD274]) surface expression on bone marrow granulocytes and monocytes, but not blasts, in both arms. In summary, combining azacitidine with durvalumab in patients with HR-MDS was feasible but with more toxicities and without significant improvement in clinical outcomes over azacitidine alone. This trial was registered at www.clinicaltrials.gov as #NCT02775903.

Microscopy suggests that glutathione S‐transferase is stored in large granules of myeloid cells in bone marrow and sparse granulocytes of the regenerating tail of lizard

AbstractMicroscopy suggests that glutathione S‐transferase is stored in large granules of myeloid cells in bone marrow and sparse granulocytes of the regenerating tail of lizard. Acta Zoologica (Stockolm). Tail regeneration in lizards occurs after an immune‐privileged blastema and is formed where various immunosuppressive cells and biomolecules keep inflammation low. Molecules that limit inflammation may include glutathione and glutathione S‐transferase (GST). These molecules reduce reactive oxidative species (ROS) and detoxify extraneous molecules. In the present study, the presence of GST has been analysed in the early phases of tail regeneration in the lizard Podarcis muralis. Using a rabbit polyclonal antibody directed against epitopes present in GST of P. muralis, a light and electron microscopy immunohistochemical and Western blotting study has been done. The study detected proteins of 25 and 32 kDa in pale‐medium electron‐dense and large granules present in promyelocytes and myelocytes of likely basophilic or eosinophilic fate that is present in the bone marrow of tail vertebrae. These cells are still proliferating and give rise to basophilic or eosinophilic granulocytes that also migrate into the regenerating tail. The enzyme stored in granules of promyelocytes and myelocytes is also localized in the cytoplasm of granulocytes present in the regenerating blastema‐cone, basophilic or/and eosinophilic. It is suggested that these granulocytes in the blastema reduce ROS and detoxify potentially inflammatory metabolites, contributing with other molecules to limit inflammation and favour regeneration.