CD177 modulates human neutrophil migration through activation-mediated integrin and chemoreceptor regulation

Proteomic Characterization of 1000 Human and Murine Neutrophils Freshly Isolated From Blood and Sites of Sterile Inflammation

Neutrophils are indispensable for defense against pathogens. Injured tissue-infiltrated neutrophils can establish a niche of chronic inflammation and promote degeneration. Studies investigated transcriptome of single-infiltrated neutrophils which could misinterpret molecular states of these post mitotic cells. However, neutrophil proteome characterization has been challenging due to low harvests from affected tissues. Here, we present a workflow to obtain proteome of 1000 murine and human tissue-infiltrated neutrophils. We generated spectral libraries containing ∼6200 mouse and ∼5300 human proteins from circulating neutrophils. 4800 mouse and 3400 human proteins were recovered from 1000 cells with 102-108 copies/cell. Neutrophils from stroke-affected mouse brains adapted to the glucose-deprived environment with increased mitochondrial activity and ROS-production, while cells invading inflamed human oral cavities increased phagocytosis and granule release. We provide an extensive protein repository for resting human and mouse neutrophils, identify proteins lost in low input samples, thus enabling the proteomic characterization of limited tissue-infiltrated neutrophils.

Proteomic profiling of the local and systemic immune response to pediatric respiratory viral infections

Viral lower respiratory tract infection (vLRTI) is a leading cause of hospitalization and death in children worldwide. Despite this, no studies have employed proteomics to characterize host immune responses to severe pediatric vLRTI in both the lower airway and systemic circulation. To address this gap, gain insights into vLRTI pathophysiology, and test a novel diagnostic approach, we assayed 1,305 proteins in tracheal aspirate (TA) and plasma from 62 critically ill children using SomaScan. We performed differential expression (DE) and pathway analyses comparing vLRTI (n=40) to controls with non-infectious acute respiratory failure (n=22), developed a diagnostic classifier using LASSO regression, and analyzed matched TA and plasma samples. We further investigated the impact of viral load and bacterial coinfection on the proteome. The TA signature of vLRTI was characterized by 200 DE proteins (Padj<0.05) with upregulation of interferons and T cell responses and downregulation of inflammation-modulating proteins including FABP and MIP-5. A nine-protein TA classifier achieved an AUC of 0.96 (95% CI 0.90-1.00) for identifying vLRTI. In plasma, the host response to vLRTI was more muted with 56 DE proteins. Correlation between TA and plasma was limited, although ISG15 was elevated in both compartments. In bacterial coinfection, we observed increases in the TNF-stimulated protein TSG-6, as well as CRP, and interferon-related proteins. Viral load correlated positively with interferon signaling and negatively with neutrophil-activation pathways. Taken together, our study provides fresh insight into the lower airway and systemic proteome of severe pediatric vLRTI, and identifies novel protein biomarkers with diagnostic potential.

Dual role of CD177 + neutrophils in inflammatory bowel disease: a review

Inflammatory bowel disease (IBD) represents a group of recurrent chronic inflammatory disorders associated with autoimmune dysregulation, typically characterized by neutrophil infiltration and mucosal inflammatory lesions. Neutrophils, as the earliest immune cells to arrive at inflamed tissues, play a dual role in the onset and progression of mucosal inflammation in IBD. Most of these cells specifically express CD177, a molecule increasingly recognized for its critical role in the pathogenesis of IBD. Under IBD-related inflammatory stimuli, CD177 is highly expressed on neutrophils and promotes their migration. CD177 + neutrophils activate bactericidal and barrier-protective functions at IBD mucosal inflammation sites and regulate the release of inflammatory mediators highly correlated with the severity of inflammation in IBD patients, thus playing a dual role. However, mitigating the detrimental effects of neutrophils in inflammatory bowel disease remains a challenge. Based on these data, we have summarized recent articles on the role of neutrophils in intestinal inflammation, with a particular emphasis on CD177, which mediates the recruitment, transepithelial migration, and activation of neutrophils, as well as their functional consequences. A better understanding of CD177 + neutrophils may contribute to the development of novel therapeutic targets to selectively modulate the protective role of this class of cells in IBD.

CD4 + T cells recruit, then engage macrophages in cognate interactions to clear Mycobacterium tuberculosis from the lungs

IFN-γ-producing CD4 + T cells are required for protection against lethal Mycobacterium tuberculosis ( Mtb ) infections. However, the ability of CD4 + T cells to suppress Mtb growth cannot be fully explained by IFN-γ or other known T cell products. In this study, we show that CD4 + T cell-derived IFN-γ promoted the recruitment of monocyte-derived macrophages (MDMs) to the lungs of Mtb -infected mice. Although the recruited MDMs became quickly and preferentially infected with Mtb , CD4 + T cells rapidly disinfected the MDMs. Clearance of Mtb from MDMs was not explained by IFN-γ, but rather by MHCII-mediated cognate interactions with CD4 + T cells. These interactions promoted MDM expression of glycolysis genes essential for Mtb control. Thus, by recruiting MDMs, CD4 + T cells initiate a cycle of bacterial phagocytosis, Mtb antigen presentation and disinfection in an attempt to clear the bacteria from the lungs.

Investigation of pulmonary inflammatory responses following intratracheal instillation of and inhalation exposure to polypropylene microplastics

BACKGROUND

Microplastics have been detected in the atmosphere as well as in the ocean, and there is concern about their biological effects in the lungs. We conducted a short-term inhalation exposure and intratracheal instillation using rats to evaluate lung disorders related to microplastics. We conducted an inhalation exposure of polypropylene fine powder at a low concentration of 2 mg/m3 and a high concentration of 10 mg/m3 on 8-week-old male Fischer 344 rats for 6 h a day, 5 days a week for 4 weeks. We also conducted an intratracheal instillation of polypropylene at a low dose of 0.2 mg/rat and a high dose of 1.0 mg/rat on 12-week-old male Fischer 344 rats. Rats were dissected from 3 days to 6 months after both exposures, and bronchoalveolar lavage fluid (BALF) and lung tissue were collected to analyze lung inflammation and lung injury.

RESULTS

Both exposures to polypropylene induced a persistent influx of inflammatory cells and expression of CINC-1, CINC-2, and MPO in BALF from 1 month after exposure. Genetic analysis showed a significant increase in inflammation-related factors for up to 6 months. The low concentration in the inhalation exposure of polypropylene also induced mild lung inflammation.

CONCLUSION

These findings suggest that inhaled polypropylene, which is a microplastic, induces persistent lung inflammation and has the potential for lung disorder. Exposure to 2 mg/m3 induced inflammatory changes and was thought to be the Lowest Observed Adverse Effect Level (LOAEL) for acute effects of polypropylene. However, considering the concentration of microplastics in a real general environment, the risk of environmental hazards to humans may be low.

CD177 on neutrophils engages stress-related behavioral changes in male mice

Persistent psychological stress can affect immune homeostasis and is a key factor in the development of depression. Many efforts are focused on the identifcation of pathways that link the immune system and mood disorders. Here, we found that psychological stress caused an increase in the frequency of brain-associated neutrophils and the level of neutrophil-specific antigen CD177 on peripheral neutrophils in male mice. Upregulated levels of blood CD177 are associated with depression in humans. Neutrophil depletion or Cd177 deficiency protected mice from stress-induced behavioral deficits. Importantly, adoptive transfer of CD177+ neutrophils from stressed mice increased the frequency of brain-associated leukocytes, including neutrophils, and caused behavioral defects in naive mice. These effects may be related to the endothelial adhesion advantage of CD177+ neutrophils and the interference of serine protease on endothelial junction. Our findings suggest a critical link between circulating CD177+ neutrophils and psychological stress-driven behavioral disorder.

CD177 is a novel IgG Fc receptor and CD177 genetic variants affect IgG-mediated function

CD177 plays an important role in the proliferation and differentiation of myeloid lineage cells including neutrophils, myelocytes, promyelocytes, megakaryocytes, and early erythroblasts in bone marrow. CD177 deficiency is a common phenotype in humans. Our previous studies revealed genetic mechanisms of human CD177 deficiency and expression variations. Up to now, immune functions of CD177 remain undefined. In the current study, we revealed human IgG as a ligand for CD177 by using flow cytometry, bead-rosette formation, and surface plasmon resonance (SPR) assays. In addition, we show that CD177 variants affect the binding capacity of CD177 for human IgG. Furthermore, we show that the CD177 genetic variants significantly affect antibody-dependent cell-mediated cytotoxicity (ADCC) function. The demonstration of CD177 as a functional IgG Fc-receptor may provide new insights into CD177 immune function and genetic mechanism underlying CD177 as biomarkers for human diseases.

Analysis of maternal Fc gamma receptor IIIb isoantibodies using immunomagnetic negative selected neutrophils

BACKGROUND AND OBJECTIVES

The isolation of neutrophils and subsequent detection of anti-human neutrophil antigens (HNA) antibodies are crucial in clinical medicine for the diagnosis of autoimmune neutropenia, neonatal alloimmune neutropenia (NAIN) and transfusion-related acute lung injury (TRALI). This study reports two cases of maternal anti-Fc-gamma-receptor-IIIb (FcγRIIIb) isoimmunization without NAIN symptoms and compares the efficiency of immunomagnetic negative selection (IMNS) with traditional dextran/Ficoll for neutrophil isolation in HNA serological assays.

MATERIALS AND METHODS

Investigating two cases of maternal anti-FcγRIIIb isoimmunization, neutrophils from three donors were isolated from 8 mL of whole blood using IMNS and dextran/Ficoll. Serological assays included the granulocyte agglutination and immunofluorescence test, monoclonal antibody immobilization of granulocyte antigens and the LABScreen Multi (One Lambda). IMNS and dextran/Ficoll were compared in terms of cell yield, viability, time, cost and purity.

RESULTS

Maternal anti-FcγRIIIb isoantibodies with FCGR3B gene deletion were detected in both cases. Newborns and fathers exhibited specific gene combinations: FCGR3B*02/FCGR3B*02 (Case 1) and FCGR3B*02/FCGR3B*03 (Case 2). IMNS outperformed dextran/Ficoll, yielding four times more neutrophils (average neutrophil counts: 18.5 × 103/μL vs. 4.5 × 103/μL), efficiently removing non-neutrophil cells and reducing processing time (30-40 min vs. 70-90 min), although it incurred a higher cost (2.7 times).

CONCLUSION

Two cases of maternal anti-FcγRIIIb isoantibodies, unrelated to NAIN, were identified. Although neutropenia has not been described in these cases, we emphasize the importance of identifying asymptomatic cases with the potential for severe neutropenia. Additionally, IMNS is introduced as a rapid, high-yield, high-purity neutrophil isolation technique, beneficial for serological assays detecting anti-HNA antibodies.

Biomarkers in bronchiectasis

Bronchiectasis is a heterogeneous disease with multiple aetiologies and diverse clinical features. There is a general consensus that optimal treatment requires precision medicine approaches focused on specific treatable disease characteristics, known as treatable traits. Identifying subtypes of conditions with distinct underlying biology (endotypes) depends on the identification of biomarkers that are associated with disease features, prognosis or treatment response and which can be applied in clinical practice. Bronchiectasis is a disease characterised by inflammation, infection, structural lung damage and impaired mucociliary clearance. Increasingly there are available methods to measure each of these components of the disease, revealing heterogeneous inflammatory profiles, microbiota, radiology and mucus and epithelial biology in patients with bronchiectasis. Using emerging biomarkers and omics technologies to guide treatment in bronchiectasis is a promising field of research. Here we review the most recent data on biomarkers in bronchiectasis.

Phage Display as a Medium for Target Therapy Based Drug Discovery, Review and Update

Phage libraries are now amongst the most prominent approaches for the identification of high-affinity antibodies/peptides from billions of displayed phages in a specific library through the biopanning process. Due to its ability to discover potential therapeutic candidates that bind specifically to targets, phage display has gained considerable attention in targeted therapy. Using this approach, peptides with high-affinity and specificity can be identified for potential therapeutic or diagnostic use. Furthermore, phage libraries can be used to rapidly screen and identify novel antibodies to develop immunotherapeutics. The Food and Drug Administration (FDA) has approved several phage display-derived peptides and antibodies for the treatment of different diseases. In the current review, we provided a comprehensive insight into the role of phage display-derived peptides and antibodies in the treatment of different diseases including cancers, infectious diseases and neurological disorders. We also explored the applications of phage display in targeted drug delivery, gene therapy, and CAR T-cell.

Integrated multi-omics and artificial intelligence to explore new neutrophils clusters and potential biomarkers in sepsis with experimental validation

Background

Sepsis, causing serious organ and tissue damage and even death, has not been fully elucidated. Therefore, understanding the key mechanisms underlying sepsis-associated immune responses would lead to more potential therapeutic strategies.

Methods

Single-cell RNA data of 4 sepsis patients and 2 healthy controls in the GSE167363 data set were studied. The pseudotemporal trajectory analyzed neutrophil clusters under sepsis. Using the hdWGCNA method, key gene modules of neutrophils were explored. Multiple machine learning methods were used to screen and validate hub genes for neutrophils. SCENIC was then used to explore transcription factors regulating hub genes. Finally, quantitative reverse transcription-polymerase chain reaction was to validate mRNA expression of hub genes in peripheral blood neutrophils of two mice sepsis models.

Results

We discovered two novel neutrophil subtypes with a significant increase under sepsis. These two neutrophil subtypes were enriched in the late state during neutrophils differentiation. The hdWGCNA analysis of neutrophils unveiled that 3 distinct modules (Turquoise, brown, and blue modules) were closely correlated with two neutrophil subtypes. 8 machine learning methods revealed 8 hub genes with high accuracy and robustness (ALPL, ACTB, CD177, GAPDH, SLC25A37, S100A8, S100A9, and STXBP2). The SCENIC analysis revealed that APLP, CD177, GAPDH, S100A9, and STXBP2 were significant associated with various transcriptional factors. Finally, ALPL, CD177, S100A8, S100A9, and STXBP2 significantly up regulated in peripheral blood neutrophils of CLP and LPS-induced sepsis mice models.

Conclusions

Our research discovered new clusters of neutrophils in sepsis. These five hub genes provide novel biomarkers targeting neutrophils for the treatment of sepsis.

CD177 drives the transendothelial migration of Treg cells enriched in human colorectal cancer

Objectives

Regulatory T (Treg) cells regulate immunity in autoimmune diseases and cancers. However, immunotherapies that target tumor-infiltrating Treg cells often induce unwanted immune responses and tissue inflammation. Our research focussed on exploring the expression pattern of CD177 in tumor-infiltrating Treg cells with the aim of identifying a potential target that can enhance immunotherapy effectiveness.

Methods

Single-cell RNA sequencing (scRNA-seq) data and survival data were obtained from public databases. Twenty-one colorectal cancer patient samples, including fresh tumor tissues, peritumoral tissues and peripheral blood mononuclear cells (PBMCs), were analysed using flow cytometry. The transendothelial activity of CD177+ Treg cells was substantiated using in vitro experiments.

Results

ScRNA-seq and flow cytometry results indicated that CD177 was exclusively expressed in intratumoral Treg cells. CD177+ Treg cells exhibited greater activation status and expressed elevated Treg cell canonical markers and immune checkpoint molecules than CD177- Treg cells. We further discovered that both intratumoral CD177+ Treg cells and CD177-overexpressing induced Treg (iTreg) cells had lower levels of PD-1 than their CD177- counterparts. Moreover, CD177 overexpression significantly enhanced the transendothelial migration of Treg cells in vitro.

Conclusions

These results demonstrated that Treg cells with higher CD177 levels exhibited an enhanced activation status and transendothelial migration capacity. Our findings suggest that CD177 may serve as an immunotherapeutic target and that overexpression of CD177 may improve the efficacy of chimeric antigen receptor T (CAR-T) cell therapy.

Peripheral priming induces plastic transcriptomic and proteomic responses in circulating neutrophils required for pathogen containment

Neutrophils rapidly respond to inflammation and infection, but to which degree their functional trajectories after mobilization from the bone marrow are shaped within the circulation remains vague. Experimental limitations have so far hampered neutrophil research in human disease. Here, using innovative fixation and single-cell-based toolsets, we profile human and murine neutrophil transcriptomes and proteomes during steady state and bacterial infection. We find that peripheral priming of circulating neutrophils leads to dynamic shifts dominated by conserved up-regulation of antimicrobial genes across neutrophil substates, facilitating pathogen containment. We show the TLR4/NF-κB signaling-dependent up-regulation of canonical neutrophil activation markers like CD177/NB-1 during acute inflammation, resulting in functional shifts in vivo. Blocking de novo RNA synthesis in circulating neutrophils abrogates these plastic shifts and prevents the adaptation of antibacterial neutrophil programs by up-regulation of distinct effector molecules upon infection. These data underline transcriptional plasticity as a relevant mechanism of functional neutrophil reprogramming during acute infection to foster bacterial containment within the circulation.

Lymphatic endothelial cell-mediated accumulation of CD177+Treg cells suppresses antitumor immunity in human esophageal squamous cell carcinoma

Regulatory T (Treg) cells are critical in shaping an immunosuppressive microenvironment to favor tumor progression and resistance to therapies. However, the heterogeneity and function of Treg cells in esophageal squamous cell carcinoma (ESCC) remain underexplored. We identified CD177 as a tumor-infiltrating Treg cell marker in ESCC. Interestingly, expression levels of CD177 and PD-1 were mutually exclusive in tumor Treg cells. CD177+ Treg cells expressed high levels of IL35, in association with CD8+ T cell exhaustion, whereas PD-1+ Treg cells expressed high levels of IL10. Pan-cancer analysis revealed that CD177+ Treg cells display increased clonal expansion compared to PD-1+ and double-negative (DN) Treg cells, and CD177+ and PD-1+ Treg cells develop from the same DN Treg cell origin. Importantly, we found CD177+ Treg cell infiltration to be associated with poor overall survival and poor response to anti-PD-1 immunotherapy plus chemotherapy in ESCC patients. Finally, we found that lymphatic endothelial cells are associated with CD177+ Treg cell accumulation in ESCC tumors, which are also decreased after anti-PD-1 immunotherapy plus chemotherapy. Our work identifies CD177+ Treg cell as a tumor-specific Treg cell subset and highlights their potential value as a prognostic marker of survival and response to immunotherapy and a therapeutic target in ESCC.

Beyond host defense and tissue injury: the emerging role of neutrophils in tissue repair

Neutrophils, the most abundant immune cells in human blood, play a fundamental role in host defense against invading pathogens and tissue injury. Neutrophils carry potentially lethal weaponry to the affected site. Inadvertent and perpetual neutrophil activation could lead to nonresolving inflammation and tissue damage, a unifying mechanism of many common diseases. The prevailing view emphasizes the dichotomy of their function, host defense versus tissue damage. However, tissue injury may also persist during neutropenia, which is associated with disease severity and poor outcome. Numerous studies highlight neutrophil phenotypic heterogeneity and functional versatility, indicating that neutrophils play more complex roles than previously thought. Emerging evidence indicates that neutrophils actively orchestrate resolution of inflammation and tissue repair and facilitate return to homeostasis. Thus, neutrophils mobilize multiple mechanisms to limit the inflammatory reaction, assure debris removal, matrix remodeling, cytokine scavenging, macrophage reprogramming, and angiogenesis. In this review, we will summarize the homeostatic and tissue-reparative functions and mechanisms of neutrophils across organs. We will also discuss how the healing power of neutrophils might be harnessed to develop novel resolution and repair-promoting therapies while maintaining their defense functions.

OMIP-100: A flow cytometry panel to investigate human neutrophil subsets

This 14-color, 13-antibody optimized multicolor immunofluorescence panel (OMIP) was designed for deep profiling of neutrophil subsets in various types of human samples to contextualize neutrophil plasticity in a range of healthy and diseased states. Markers present in the OMIP allow the profiling of neutrophil subsets associated with ontogeny, migration, phagocytosis capacity, granule release, and immune modulation. For panel design, we ensured that the commonly available fluorophores FITC/AF488, PE, and APC were assigned to the intracellular subset marker Olfactomedin 4, the maturity and activation marker CD10, and whole blood subset marker CD177, respectively. These markers can be easily replaced without affecting the core identification of neutrophils, enabling antibodies to new neutrophil antigens of interest or for fluorescent substrates to assess different neutrophil functions to be easily explored. Panel optimization was performed on whole blood and purified neutrophils. We demonstrate applications on clinical samples (whole blood and saliva) and experimental endpoints (purified neutrophils stimulated through an in vitro transmigration assay). We hope that providing a uniform platform to analyze neutrophil plasticity in various sample types will facilitate the future understanding of neutrophil subsets in health and disease.

The link between neutrophils, NETs, and NLRP3 inflammasomes: The dual effect of CD177 and its therapeutic potential in acute respiratory distress syndrome/acute lung injury

Neutrophils are important inflammatory effector cells that protect against foreign invasion but also cause self-harm. Numerous neutrophils infiltrate the lungs in acute respiratory distress syndrome/acute lung injury (ARDS/ALI) patients. However, the exact impact of neutrophil infiltration on ARDS's onset and progression remains unclear. To investigate this, we analyzed two ARDS-related datasets from the Gene Expression Omnibus public database and discovered an association between CD177, a neutrophil-specific surface protein, and ARDS progression. We used quantitative flow cytometry to assess CD177+ neutrophils in the peripheral blood of clinical ARDS patients vs healthy controls, finding a significant increase in CD177+ neutrophils percentage among total neutrophils in ARDS patients. This finding was further confirmed in ALI mouse models. Subsequent animal experiments showed that anti-CD177 effectively reduces pulmonary edema, neutrophil infiltration, and inflammatory cytokine release, along with a decrease in reactive oxygen species (ROS) and myeloperoxidase (MPO) levels. We also established an in vitro co-culture system to mimic neutrophil and lung epithelial cell interactions. In the anti-CD177 group, we observed decreased expression of NLRP3, caspase 1, peptidyl arginine deiminase (PAD4), MPO, and ROS, along with a reduction in certain inflammatory cytokines. These results indicate a crucial role for the CD177 gene in ARDS's development and progression. Inhibiting CD177 may help mitigate excessive activation of NLRP3 inflammasomes, ROS, and neutrophil extracellular traps (NETs), thus alleviating ARDS.

CD177 is a novel IgG Fc receptor and CD177 genetic variants affect IgG-mediated function

CD177 plays an important role in the proliferation and differentiation of myeloid lineage cells including neutrophils, myelocytes, promyelocytes, megakaryocytes, and early erythroblasts in bone marrow. CD177 deficiency is a common phenotype in humans. Our previous studies revealed genetic mechanisms of human CD177 deficiency and expression variations. Up to now, immune functions of CD177 remain undefined. In the current study, we revealed human IgG as a ligand for CD177 by using flow cytometry, bead-rosette formation, and surface plasmon resonance (SPR) assays. In addition, we show that CD177 variants affect the binding capacity of CD177 for human IgG. Furthermore, we showed that the CD177 genetic variants significantly affect antibody-dependent cell-mediated cytotoxicity (ADCC) function. The demonstration of CD177 as a functional IgG Fc-receptor may provide new insights into CD177 immune function and genetic mechanism underlying CD177 as biomarkers for human diseases.

The Rac-GEF Tiam1 controls integrin-dependent neutrophil responses

Rac GTPases are required for neutrophil adhesion and migration, and for the neutrophil effector responses that kill pathogens. These Rac-dependent functions are impaired when neutrophils lack the activators of Rac, Rac-GEFs from the Prex, Vav, and Dock families. In this study, we demonstrate that Tiam1 is also expressed in neutrophils, governing focal complexes, actin cytoskeletal dynamics, polarisation, and migration, in a manner depending on the integrin ligand to which the cells adhere. Tiam1 is dispensable for the generation of reactive oxygen species but mediates degranulation and NETs release in adherent neutrophils, as well as the killing of bacteria. In vivo, Tiam1 is required for neutrophil recruitment during aseptic peritonitis and for the clearance of Streptococcus pneumoniae during pulmonary infection. However, Tiam1 functions differently to other Rac-GEFs. Instead of promoting neutrophil adhesion to ICAM1 and stimulating β2 integrin activity as could be expected, Tiam1 restricts these processes. In accordance with these paradoxical inhibitory roles, Tiam1 limits the fMLP-stimulated activation of Rac1 and Rac2 in adherent neutrophils, rather than activating Rac as expected. Tiam1 promotes the expression of several regulators of small GTPases and cytoskeletal dynamics, including αPix, Psd4, Rasa3, and Tiam2. It also controls the association of Rasa3, and potentially αPix, Git2, Psd4, and 14-3-3ζ/δ, with Rac. We propose these latter roles of Tiam1 underlie its effects on Rac and β2 integrin activity and on cell responses. Hence, Tiam1 is a novel regulator of Rac-dependent neutrophil responses that functions differently to other known neutrophil Rac-GEFs.

Dysregulated neutrophil extracellular traps formation in sepsis

The migration and antimicrobial functions of neutrophils seem to be impaired during sepsis and contribute to the dysregulation of immune responses and disease pathogenesis. However, the role of neutrophil extracellular traps (NETs) remains to be clarified. The study aimed to analyse sequential phenotypic and functional changes of neutrophils during the time following the diagnosis of sepsis. We prospectively enrolled 49 septic and 18 non-septic patients from the intensive care unit (ICU) and emergency room (ER) and 20 healthy volunteers (HV). Baseline blood samples from septic and non-septic patients were collected within 12 h of admission to the hospital. Additional septic samples were drawn at 24, 48 and 72 h after baseline. Neutrophil phenotype and degranulation capacity were assessed by flow cytometry and NET formation was quantified by fluorescence. Neutrophils from septic patients exhibited increased CD66b, CD11b and CD177 expression but displayed reduced NET formation at baseline compared with non-septic patients and HV controls. Neutrophils expressing CD177 interacted less with platelets, were related to reduced NETosis and tended to indicate a worse sepsis outcome. In vitro experiments revealed that neutrophil function is compromised by the origin of sepsis, including the pathogen type and the affected organ. Assessing a decision tree model, our study showed that CD11b expression and NETosis values are useful variables to discriminate septic from non-septic patients. We conclude that sepsis induces changes in neutrophil phenotype and function that may compromise the effective capacity of the host to eliminate pathogens.

Early Pharmacodynamic Changes Measured Using RNA Sequencing of Peripheral Blood from Patients in a Phase I Study with Mitazalimab, a Potent CD40 Agonistic Monoclonal Antibody

CD40-targeting therapies can enhance the dendritic cell priming of tumor-specific T cells and repolarize intratumoral macrophages to alleviate the tumoral immunosuppressive environment and remodel the extracellular matrix. Mitazalimab is a potent agonistic CD40 monoclonal IgG1 antibody currently under clinical development. This study used RNA sequencing of blood samples from a subset of patients from a Phase I trial with mitazalimab (NCT02829099) to assess peripheral pharmacodynamic activity. We found that mitazalimab induced transient peripheral transcriptomic alterations (at 600 µg/kg and 900 µg/kg dose administered intravenously), which mainly were attributed to immune activation. In particular, the transcriptomic alterations showed a reduction in effector cells (e.g., CD8+ T cells and natural killer cells) and B cells peripherally with the remaining cells (e.g., dendritic cells, monocytes, B cells, and natural killer cells) showing transcription profiles consistent with activation. Lastly, distinct patient subgroups based on the pattern of transcriptomic alterations could be identified. In summary, the data presented herein reinforce the anticipated mode of action of mitazalimab and support its ongoing clinical development.

Proteomic aptamer analysis reveals serum biomarkers associated with disease mechanisms and phenotypes of systemic sclerosis

Background

Systemic sclerosis (SSc) is an autoimmune connective tissue disease that affects multiple organs, leading to elevated morbidity and mortality with limited treatment options. The early detection of organ involvement is challenging as there is currently no serum marker available to predict the progression of SSc. The aptamer technology proteomic analysis holds the potential to correlate SSc manifestations with serum proteins up to femtomolar concentrations.

Methods

This is a two-tier study of serum samples from women with SSc (including patients with interstitial lung disease - ILD - at high-resolution CT scan) and age-matched healthy controls (HC) that were first analyzed with aptamer-based proteomic analysis for over 1300 proteins. Proposed associated proteins were validated by ELISA first in an independent cohort of patients with SSc and HC, and selected proteins subject to further validation in two additional cohorts.

Results

The preliminary aptamer-based proteomic analysis identified 33 proteins with significantly different concentrations in SSc compared to HC sera and 9 associated with SSc-ILD, including proteins involved in extracellular matrix formation and cell-cell adhesion, angiogenesis, leukocyte recruitment, activation, and signaling. Further validations in independent cohorts ultimately confirmed the association of specific proteins with early SSc onset, specific organ involvement, and serum autoantibodies.

Conclusions

Our multi-tier proteomic analysis identified serum proteins discriminating patients with SSc and HC or associated with different SSc subsets, disease duration, and manifestations, including ILD, skin involvement, esophageal disease, and autoantibodies.

Lrig1-expression confers suppressive function to CD4+ cells and is essential for averting autoimmunity via the Smad2/3/Foxp3 axis

Regulatory T cells (Treg) are CD4+ T cells with immune-suppressive function, which is defined by Foxp3 expression. However, the molecular determinants defining the suppressive population of T cells have yet to be discovered. Here we report that the cell surface protein Lrig1 is enriched in suppressive T cells and controls their suppressive behaviors. Within CD4+ T cells, Treg cells express the highest levels of Lrig1, and the expression level is further increasing with activation. The Lrig1+ subpopulation from T helper (Th) 17 cells showed higher suppressive activity than the Lrig1- subpopulation. Lrig1-deficiency impairs the suppressive function of Treg cells, while Lrig1-deficient naïve T cells normally differentiate into other T cell subsets. Adoptive transfer of CD4+Lrig1+ T cells alleviates autoimmune symptoms in colitis and lupus nephritis mouse models. A monoclonal anti-Lrig1 antibody significantly improves the symptoms of experimental autoimmune encephalomyelitis. In conclusion, Lrig1 is an important regulator of suppressive T cell function and an exploitable target for treating autoimmune conditions.

Sex disparities in non-small cell lung cancer: mechanistic insights from a cRaf transgenic disease model

BACKGROUND

Women are at greater risk of developing non-small cell lung cancer (NSCLC), yet the underlying causes remain unclear.

METHODS

We performed whole genome scans in lung tumours of cRaf transgenic mice and identified miRNA, transcription factor and hormone receptor dependent gene regulations. We confirmed hormone receptors by immunohistochemistry and constructed regulatory gene networks by considering experimentally validated miRNA-gene and transcription factor-miRNA/gene targets. Bioinformatics, genomic foot-printing and gene enrichment analysis established sex-specific circuits of lung tumour growth. Translational research involved a large cohort of NSCLC patients. We evaluated commonalities in sex-specific NSCLC gene regulations between mice and humans and determined their prognostic value in Kaplan-Meier survival statistics and COX proportional hazard regression analysis.

FINDINGS

Overexpression of the cRaf kinase elicited an extraordinary 8-fold increase in tumour growth among females, and nearly 70% of the 112 differentially expressed genes (DEGs) were female specific. We identified oncogenes, oncomirs, tumour suppressors, cell cycle regulators and MAPK/EGFR signalling molecules, which prompted sex-based differences in NSCLC, and we deciphered a regulatory gene-network, which protected males from accelerated tumour growth. Strikingly, 41% of DEGs are targets of hormone receptors, and the majority (85%) are oestrogen receptor (ER) dependent. We confirmed the role of ER in a large cohort of NSCLC patients and validated 40% of DEGs induced by cRaf in clinical tumour samples.

INTERPRETATION

We report the molecular wiring that prompted sex disparities in tumour growth. This allowed us to propose the development of molecular targeted therapies by jointly blocking ER, CDK1 and arginase 2 in NSCLC.

FUNDING

We gratefully acknowledge the financial support of the Lower Saxony Ministry of Culture and Sciences and Volkswagen Foundation, Germany to JB (25A.5-7251-99-3/00) and of the Chinese Scholarship Council to SZ (202008080022). This publication is funded by the Deutsche Forschungsgemeinschaft (DFG) as part of the "Open Access Publikationskosten" program.

Neutrophil subsets in noncancer liver diseases: Cellular crosstalk and therapeutic targets

Neutrophils are the most abundant circulating granulocytes, linking innate and adaptive immunity. Neutrophils can regulate inflammatory and immune responses through degranulation, reactive oxygen species generation, the production of cytokines and chemokines, and NETosis. Emerging evidence has indicated that neutrophils contribute to the pathogenesis of various noncancer liver diseases, including nonalcoholic fatty liver disease, alcohol-associated liver disease, hepatic ischemia-reperfusion injury, and liver fibrosis. Cellular interactions among neutrophils, other immune cells, and nonimmune cells constitute a complex network that regulates the immune microenvironment of the liver. This review summarizes novel neutrophil subtypes, including CD177+ neutrophils and low-density neutrophils. Moreover, we provide an overview of the cellular cros stalk of neutrophils in noncancer liver diseases, aiming to shed new light on mechanistic studies of novel neutrophil subtypes. In addition, we discuss the potential of neutrophils as therapeutic targets in noncancer liver diseases, including inhibitors targeting NETosis, granule proteins, and chemokines.

Platelet ITGA2B inhibits caspase-8 and Rip3/Mlkl-dependent platelet death though PTPN6 during sepsis

Platelets play an important role in the pathogenesis of sepsis and platelet transfusion is a therapeutic option for sepsis patients, although the exact mechanisms have not been elucidated so far. ITGA2B encodes the αIIb protein in platelets, and its upregulation in sepsis is associated with increased mortality rate. Here, we generated a Itga2b (Q887X) knockin mouse, which significantly reduced ITGA2B expression of platelet and megakaryocyte. The decrease of ITGA2B level aggravated the death of septic mice. We analyzed the transcriptomic profiles of the platelets using RNA sequencing. Our findings suggest that ITGA2B upregulates PTPN6 in megakaryocytes via the transcription factors Nfkb1 and Rel. Furthermore, PTPN6 inhibits platelet apoptosis and necroptosis during sepsis by targeting the Ripk1/Ripk3/Mlkl and caspase-8 pathways. This prevents Kupffer cells from rapidly clearing activated platelets, and eventually maintains vascular integrity during sepsis. Our findings indicate a new function of ITGA2B in the regulation of platelet death during sepsis.

Transcriptomic analysis identifies novel candidates in cardiorenal pathology mediated by chronic peritoneal dialysis

Peritoneal dialysis (PD) is associated with increased cardiovascular (CV) risk. Studies of PD-related CV pathology in animal models are lacking despite the clinical importance. Here we introduce the phenotypic evaluation of a rat model of cardiorenal syndrome in response to chronic PD, complemented by a rich transcriptomic dataset detailing chronic PD-induced changes in left ventricle (LV) and kidney tissues. This study aims to determine how PD alters CV parameters and risk factors while identifying pathways for potential therapeutic targets. Sprague Dawley rats underwent Sham or 5/6 nephrectomy (5/6Nx) at 10 weeks of age. Six weeks later an abdominal dialysis catheter was placed in all rats before random assignment to Control or PD (3 daily 1-h exchanges) groups for 8 days. Renal and LV pathology and transcriptomic analysis was performed. The PD regimen reduced circulating levels of BUN in 5/6Nx, indicating dialysis efficacy. PD did not alter blood pressure or cardiovascular function in Sham or 5/6Nx rats, though it attenuated cardiac hypertrophy. Importantly PD increased serum triglycerides in 5/6Nx rats. Furthermore, transcriptomic analysis revealed that PD induced numerous changed transcripts involved with inflammatory pathways, including neutrophil activation and atherosclerosis signaling. We have adapted a uremic rat model of chronic PD. Chronic PD induced transcriptomic changes related to inflammatory signaling that occur independent of 5/6Nx and augmented circulating triglycerides and predicted atherosclerosis signaling in 5/6Nx LV tissues. The changes are indicative of increased CV risk due to PD and highlight several pathways for potential therapeutic targets.

Integrative Proteomics and N-Glycoproteomics Analyses of Rheumatoid Arthritis Synovium Reveal Immune-Associated Glycopeptides

Rheumatoid arthritis (RA) is a typical autoimmune disease characterized by synovial inflammation, synovial tissue hyperplasia, and destruction of bone and cartilage. Protein glycosylation plays key roles in the pathogenesis of RA but in-depth glycoproteomics analysis of synovial tissues is still lacking. Here, by using a strategy to quantify intact N-glycopeptides, we identified 1260 intact N-glycopeptides from 481 N-glycosites on 334 glycoproteins in RA synovium. Bioinformatics analysis revealed that the hyper-glycosylated proteins in RA were closely linked to immune responses. By using DNASTAR software, we identified 20 N-glycopeptides whose prototype peptides were highly immunogenic. We next calculated the enrichment scores of nine types of immune cells using specific gene sets from public single-cell transcriptomics data of RA and revealed that the N-glycosylation levels at some sites, such as IGSF10_N2147, MOXD2P_N404, and PTCH2_N812, were significantly correlated with the enrichment scores of certain immune cell types. Furthermore, we showed that aberrant N-glycosylation in the RA synovium was related to increased expression of glycosylation enzymes. Collectively, this work presents, for the first time, the N-glycoproteome of RA synovium and describes immune-associated glycosylation, providing novel insights into RA pathogenesis.

Trail Formation Alleviates Excessive Adhesion and Maintains Efficient Neutrophil Migration

Migrating neutrophils are found to leave behind subcellular trails in vivo, but the underlying mechanisms remain unclear. Here, an in vitro cell migration test plus an in vivo observation was applied to monitor neutrophil migration on intercellular cell adhesion molecule-1 (ICAM-1) presenting surfaces. Results indicated that migrating neutrophils left behind long-lasting, chemokine-containing trails. Trail formation tended to alleviate excessive cell adhesion enhanced by the trans-binding antibody and maintain efficient cell migration, which was associated with differential instantaneous edge velocity between the cell front and rear. CD11a and CD11b worked differently in inducing trail formation with polarized distributions on the cell body and uropod. Trail release at the cell rear was attributed to membrane ripping, in which β2-integrin was disrupted from the cell membrane through myosin-mediated rear contraction and integrin-cytoskeleton dissociation, potentiating a specialized strategy of integrin loss and cell deadhesion to maintain efficient migration. Moreover, neutrophil trails left on the substrate served as immune forerunners to recruit dendritic cells. These results provided an insight in elucidating the mechanisms of neutrophil trail formation and deciphering the roles of trail formation in efficient neutrophil migration.

Clinical exome sequencing findings in 1589 patients

Clinical exome sequencing (CES) is important for the diagnosis of Mendelian diseases, which are clinically and etiologically heterogeneous. Sharing of large amounts of CES data associated with clinical findings will increase the accuracy of variant interpretation. We performed a retrospective study to state the diagnostic yield of CES in 1589 patients with a wide phenotypic spectrum. CES was performed using the Sophia Clinical Exome Sequencing Kit with 4493 genes, followed by sequencing on a NextSeq 500 system. The diagnosis rate was 36.8% when only pathogenic and likely pathogenic variants were included. Consanguineous unions and positive family history were associated with a high diagnostic yield. The neurological disease group had the highest number of patients. The groups with high diagnosis rates were ear, eye, and muscle disease groups. Seven candidate genes (EFHC2, HSPB3, FAAH2, ITGB1, GYG2, CD177, and CSTF2T) that are not yet associated with human diseases were identified. Owing to the high diagnostic yield of CES compared with that of other genetic tests, it can be used as a standard diagnostic test in patients with rare genetic disorders that require a wide differential diagnosis, especially in laboratories with limited resources.

Association of Circulating Neutrophils with Relative Volume of Lipid-Rich Necrotic Core of Coronary Plaques in Stable Patients: A Substudy of SMARTool European Project

BACKGROUND AND AIMS

Coronary atherosclerosis is a chronic non-resolving inflammatory process wherein the interaction of innate immune cells and platelets plays a major role. Circulating neutrophils, in particular, adhere to the activated endothelium and migrate into the vascular wall, promoting monocyte recruitment and influencing plaque phenotype and stability at all stages of its evolution. We aimed to evaluate, by flow cytometry, if blood neutrophil number and phenotype-including their phenotypic relationships with platelets, monocytes and lymphocytes-have an association with lipid-rich necrotic core volume (LRNCV), a generic index of coronary plaque vulnerability, in a group of stable patients with chronic coronary syndrome (CCS).

METHODS

In 55 patients, (68.53 ± 1.07 years of age, mean ± SEM; 71% male), the total LRNCV in each subject was assessed by a quantitative analysis of all coronary plaques detected by computed tomography coronary angiography (CTCA) and was normalized to the total plaque volume. The expression of CD14, CD16, CD18, CD11b, HLA-DR, CD163, CCR2, CCR5, CX3CR1, CXCR4 and CD41a cell surface markers was quantified by flow cytometry. Adhesion molecules, cytokines and chemokines, as well as MMP9 plasma levels, were measured by ELISA.

RESULTS

On a per-patient basis, LRNCV values were positively associated, by a multiple regression analysis, with the neutrophil count (n°/µL) (p = 0.02), neutrophil/lymphocyte ratio (p = 0.007), neutrophil/platelet ratio (p = 0.01), neutrophil RFI CD11b expression (p = 0.02) and neutrophil-platelet adhesion index (p = 0.01). Significantly positive multiple regression associations of LRNCV values with phenotypic ratios between neutrophil RFI CD11b expression and several lymphocyte and monocyte surface markers were also observed. In the bivariate correlation analysis, a significantly positive association was found between RFI values of neutrophil-CD41a+ complexes and neutrophil RFI CD11b expression (p < 0.0001).

CONCLUSIONS

These preliminary findings suggest that a sustained increase in circulating neutrophils, together with the up-regulation of the integrin/activation membrane neutrophil marker CD11b may contribute, through the progressive intra-plaque accumulation of necrotic/apoptotic cells exceeding the efferocytosis/anti-inflammatory capacity of infiltrating macrophages and lymphocytes, to the relative enlargement of the lipid-rich necrotic core volume of coronary plaques in stable CAD patients, thus increasing their individual risk of acute complication.

Neutrophil heterogeneity and emergence of a distinct population of CD11b/CD18-activated low-density neutrophils after trauma

INTRODUCTION

Multiple large clinical trauma trials have documented an increased susceptibility to infection after injury. Although neutrophils (polymorphonuclear leukocytes [PMNs]) were historically considered a homogeneous cell type, we hypothesized that injury could alter neutrophil heterogeneity and predispose to dysfunction. To explore whether trauma modifies PMN heterogeneity, we performed an observational mass-spectrometry-based cytometry study on total leukocytes and low-density PMNs found in the peripheral blood mononuclear cell fraction of leukocytes from healthy controls and trauma patients.

METHODS

A total of 74 samples from 12 trauma patients, each sampled at 1 or more time points, and matched controls were fractionated and profiled by mass-spectrometry-based cytometry using a panel of 44 distinct markers. After deconvolution and conservative gating on neutrophils, data were analyzed using Seurat, followed by clustering of principal components.

RESULTS

Eleven distinct neutrophil populations were resolved in control and trauma neutrophils based on differential protein surface marker expression. Trauma markedly altered the basal heterogeneity of neutrophil subgroups seen in the control samples, with loss of a dominant population of resting neutrophils marked by high expression of C3AR and low levels of CD63, CD64, and CD177 (cluster 1), and expansion of two alternative neutrophil populations, one of which is marked by high expression of CD177 with suppression of CD10, CD16, C3AR, CD63, and CD64 (cluster 6). Remarkably, following trauma, a substantially larger percentage of neutrophils sediment in the monocyte fraction. These low-density neutrophils bear markers of functional exhaustion and form a unique trauma-induced population (cluster 9) with markedly upregulated expression of active surface adhesion molecules (activated CD11b/CD18), with suppression of nearly all other surface markers, including receptors for formyl peptides, leukotrienes, chemokines, and complement.

CONCLUSION

Circulating neutrophils demonstrate considerable evidence of functional heterogeneity that is markedly altered by trauma. Trauma induces evolution of a novel, exhausted, low-density neutrophil population with immunosuppressive features.

Proteomics reveals antiviral host response and NETosis during acute COVID-19 in high-risk patients

SARS-CoV-2 remains an acute threat to human health, endangering hospital capacities worldwide. Previous studies have aimed at informing pathophysiologic understanding and identification of disease indicators for risk assessment, monitoring, and therapeutic guidance. While findings start to emerge in the general population, observations in high-risk patients with complex pre-existing conditions are limited. We addressed the gap of existing knowledge with regard to a differentiated understanding of disease dynamics in SARS-CoV-2 infection while specifically considering disease stage and severity. We biomedically characterized quantitative proteomics in a hospitalized cohort of COVID-19 patients with mild to severe symptoms suffering from different (co)-morbidities in comparison to both healthy individuals and patients with non-COVID related inflammation. Deep clinical phenotyping enabled the identification of individual disease trajectories in COVID-19 patients. By the use of the individualized disease phase assignment, proteome analysis revealed a severity dependent general type-2-centered host response side-by-side with a disease specific antiviral immune reaction in early disease. The identification of phenomena such as neutrophil extracellular trap (NET) formation and a pro-coagulatory response characterizing severe disease was successfully validated in a second cohort. Together with the regulation of proteins related to SARS-CoV-2-specific symptoms identified by proteome screening, we not only confirmed results from previous studies but provide novel information for biomarker and therapy development.

Ginsenoside Rg1 as a promising adjuvant agent for enhancing the anti-cancer functions of granulocytes inhibited by noradrenaline

Introduction

In recent years, numerous studies have confirmed that chronic stress is closely related to the development of cancer. Our previous research showed that high levels of stress hormones secreted in the body during chronic stress could inhibit the cancer-killing activity of granulocytes, which could further promote the development of cancer. Therefore, reversing the immunosuppressive effect of stress hormones on granulocytes is an urgent problem in clinical cancer treatment. Here, we selected noradrenaline (NA) as a representative stress hormone.

Methods and results

After screening many traditional Chinese herbal medicine active ingredients, a promising compound, ginsenoside Rg1, attracted our attention. We verified the immunoprotective effect of ginsenoside Rg1 on granulocytes in vitro and ex vivo, and attempted to understand its potential immunoprotective mechanism. We confirmed the immunoprotective effect of ginsenoside Rg1 on granulocytes using cell and animal experiments. Cell counting kit-8 (CCK-8) and ex vivo experiments were performed to investigate the immunoprotective effects of ginsenoside Rg1 on the anti-cancer function of granulocytes inhibited by NA. Transcriptome sequencing analysis and qRT-PCR showed that NA elevated the mRNA expression of ARG2, MMP1, S100A4, and RAPSN in granulocytes, thereby reducing the anti-cancer function of granulocytes. In contrast, ginsenoside Rg1 downregulated the mRNA expression of ARG2, MMP1, S100A4, and RAPSN, and upregulated the mRNA expression of LAMC2, DSC2, KRT6A, and FOSB, thereby enhancing the anti-cancer function of granulocytes inhibited by NA. Transwell cell migration experiments were performed to verify that ginsenoside Rg1 significantly enhanced the migration capability of granulocytes inhibited by NA. Tumor-bearing model mice were used to verify the significant immunoprotective effects in vivo. Finally, CCK-8 and hematoxylin and eosin staining experiments indicated that ginsenoside Rg1 exhibited high biosafety in vitro and in vivo.

Discussion

In future clinical treatments, ginsenoside Rg1 may be used as an adjuvant agent for cancer treatment to alleviate chronic stress-induced adverse events in cancer patients.

Distinct subsets of neutrophils crosstalk with cytokines and metabolites in patients with sepsis

Sepsis is a life-threatening condition caused by a dysregulated host response to infection. Despite continued efforts to understand the pathophysiology of sepsis, no effective therapies are currently available. While singular components of the aberrant immune response have been investigated, comprehensive studies linking different data layers are lacking. Using an integrated systems immunology approach, we evaluated neutrophil phenotypes and concomitant changes in cytokines and metabolites in patients with sepsis. Our findings identify differentially expressed mature and immature neutrophil subsets in patients with sepsis. These subsets correlate with various proteins, metabolites, and lipids, including pentraxin-3, angiopoietin-2, and lysophosphatidylcholines, in patients with sepsis. These results enabled the construction of a statistical model based on weighted multi-omics linear regression analysis for sepsis biomarker identification. These findings could help inform early patient stratification and treatment options, and facilitate further mechanistic studies targeting the trifecta of surface marker expression, cytokines, and metabolites.

Diagnostic, prognostic, and immunological roles of CD177 in cervical cancer

BACKGROUND

CD177, an indicator of prognosis in diverse cancers, is involved in the physiological processes of various tumor cells, and acts as an immune molecule with novel functions in cancer pathogenesis. However, the diagnostic, prognostic, and immunological role of CD177 in cervical cancer remains unclear.

METHODS

Utilizing publicly available databases and integrating several bioinformatics analysis methods, we evaluated the expression level of CD177 in cervical cancer by GENT2, HPA, and GEO databases. And the experiments of western blot and immunohistochemical staining were used to test the hypothesis. The Kaplan-Meier Plotter database, Xena Shiny, and the constructed nomogram were clearly demonstrated its prognostic value for patients. Gene set enrichment analysis explored the relationship between CD177 and cervical cancer immune responses and immune cells infiltration level. In addition, we investigated the association between CD177 expression and stromal score, immune score, immune checkpoint, and drug sensitivity by TCGA RNA-seq data.

RESULTS

CD177 was apparently expressed at low levels in cervical cancer and predicted a poor survival rate for patients. CD177 significantly activated immune-related signaling pathways and had a positive relationship with immune cell infiltration level. The high CD177 expression group possessed the high stromal score and immune score. CD177 had potential interactions with CTLA4, CD27, BLTA, CD200R1, CD80, NRP1, TNFRSF25, TIGIT, ICOS, and TNFSF9 checkpoint markers. And CD177 expression was positively relevant with drug sensitivity for Lapatinib, Belinostat, ATRA, Gefitinib, Navitoclax, and Tamoxifen.

SIGNIFICANCE

These findings may shed light on the vital role of CD177 in cervical cancer diagnosis, prognosis, and immunological functions, and it may be a promising predictor and potential factor for cervical cancer patients.

A shared tissue transcriptome signature and pathways in psoriasis and ulcerative colitis

Despite multiple efficacious therapies in common between psoriasis (PS) and Ulcerative Colitis (UC), mechanisms underlying their common pathophysiology remain largely unclear. Here we sought to establish a link by evaluating expression differences and pathway alterations in diseased tissues. We identified two sets of differentially expressed genes (DEGs) between lesional and nonlesional tissues in meta-analyses of data collected from baseline samples in 3 UC and then 3 PS available clinical studies from Pfizer. A shared gene signature was defined by 190 DEGs common to both diseases. Commonly dysregulated pathways identified via enrichment analysis include interferon signaling, partly driven by genes IFI6, CXCL9, CXCL10 and CXCL11, which may attract chemotaxis of Th1 cells to inflammatory sites; IL-23 pathway (IL-23A, CCL20, PI3, CXCL1, LCN2); and Th17 pathway except IL-17A. Elevated expression of costimulatory molecules ICOS and CTLA4 suggests ongoing T-cell activation in both diseases. The clinical value of the shared signature is demonstrated by a gene set improvement score reflecting post-treatment molecular improvement for each disease. This is the first study using transcriptomic meta-analysis to define a tissue gene signature and pathways dysregulated in both PS and UC. These findings suggest immune mechanisms may initiate and sustain inflammation similarly in the two diseases.

Extracellular vesicles from pristane-treated CD38-deficient mice express an anti-inflammatory neutrophil protein signature, which reflects the mild lupus severity elicited in these mice

In CD38-deficient (Cd38-/-) mice intraperitoneal injection of pristane induces a lupus-like disease, which is milder than that induced in WT mice, showing significant differences in the inflammatory and autoimmune processes triggered by pristane. Extracellular vesicles (EV) are present in all body fluids. Shed by cells, their molecular make-up reflects that of their cell of origin and/or tissue pathological situation. The aim of this study was to analyze the protein composition, protein abundance, and functional clustering of EV released by peritoneal exudate cells (PECs) in the pristane experimental lupus model, to identify predictive or diagnostic biomarkers that might discriminate the autoimmune process in lupus from inflammatory reactions and/or normal physiological processes. In this study, thanks to an extensive proteomic analysis and powerful bioinformatics software, distinct EV subtypes were identified in the peritoneal exudates of pristane-treated mice: 1) small EV enriched in the tetraspanin CD63 and CD9, which are likely of exosomal origin; 2) small EV enriched in CD47 and CD9, which are also enriched in plasma-membrane, membrane-associated proteins, with an ectosomal origin; 3) small EV enriched in keratins, ECM proteins, complement/coagulation proteins, fibrin clot formation proteins, and endopetidase inhibitor proteins. This enrichment may have an inflammation-mediated mesothelial-to-mesenchymal transition origin, representing a protein corona on the surface of peritoneal exudate EV; 4) HDL-enriched lipoprotein particles. Quantitative proteomic analysis allowed us to identify an anti-inflammatory, Annexin A1-enriched pro-resolving, neutrophil protein signature, which was more prominent in EV from pristane-treated Cd38-/- mice, and quantitative differences in the protein cargo of the ECM-enriched EV from Cd38-/- vs WT mice. These differences are likely to be related with the distinct inflammatory outcome shown by Cd38-/- vs WT mice in response to pristane treatment. Our results demonstrate the power of a hypothesis-free and data-driven approach to transform the heterogeneity of the peritoneal exudate EV from pristane-treated mice in valuable information about the relative proportion of different EV in a given sample and to identify potential protein markers specific for the different small EV subtypes, in particular those proteins defining EV involved in the resolution phase of chronic inflammation.

Targeted nanoparticles modify neutrophil function in vivo

Neutrophils play critical roles in a broad spectrum of clinical conditions. Accordingly, manipulation of neutrophil function may provide a powerful immunotherapeutic approach. However, due to neutrophils characteristic short half-life and their large population number, this possibility was considered impractical. Here we describe the identification of peptides which specifically bind either murine or human neutrophils. Although the murine and human neutrophil-specific peptides are not cross-reactive, we identified CD177 as the neutrophil-expressed binding partner in both species. Decorating nanoparticles with a neutrophil-specific peptide confers neutrophil specificity and these neutrophil-specific nanoparticles accumulate in sites of inflammation. Significantly, we demonstrate that encapsulating neutrophil modifying small molecules within these nanoparticles yields specific modulation of neutrophil function (ROS production, degranulation, polarization), intracellular signaling and longevity both in vitro and in vivo. Collectively, our findings demonstrate that neutrophil specific targeting may serve as a novel mode of immunotherapy in disease.

Ubiquitin E3 ligase FBXO21 regulates cytokine-mediated signaling pathways, but is dispensable for steady-state hematopoiesis

Hematopoietic cell fate decisions such as self-renewal and differentiation are highly regulated through multiple molecular pathways. One pathway, the ubiquitin proteasome system (UPS), controls protein levels by tagging them with polyubiquitin chains and promoting their degradation through the proteasome. Ubiquitin E3 ligases serve as the substrate-recognition component of the UPS. By investigating the FBOX family of E3 ligases, we discovered that Fbxo21 was highly expressed in the hematopoietic stem and progenitor cell (HSPC) population, and exhibited low to no expression in mature myeloid populations. To determine the role of FBXO21 on HSPC maintenance, self-renewal, and differentiation, we generated shRNAs against FBXO21 and a hematopoiesis-specific Fbxo21 conditional knockout (cKO) mouse model. We found that silencing FBXO21 in HSPCs led to a loss in colony formation and an increase in cell differentiation in vitro. Additionally, stressing the HSPC populations in our Fbxo21 cKO mouse with 5-fluorouracil injections resulted in a decrease in survival, despite these populations exhibiting minimal alterations during steady-state hematopoiesis. Although FBXO21 has previously been proposed to regulate cytokine signaling via ASK and p38, our results indicate that depletion of FBXO21 led to altered ERK signaling in vitro. Together, these findings suggest ubiquitin E3 ligase FBXO21 regulates HSPCs through cytokine-mediated pathways.

Meta-Analytic Comparison of Global RNA Transcriptomes of Acute and Chronic Myeloid Leukemia Cells Reveals Novel Gene Candidates Governing Myeloid Malignancies

Simple Summary

Despite advances in the understanding of genetic risk factors and molecular mechanisms underlying acute myeloid leukemia (AML) and chronic myeloid leukemia (CML), clinical outcomes of current therapies in terms of disease relapse and mortality rate pose a great economic and social burden. To overcome this, the identification of new molecular prognostic biomarkers and pharmacological targets is crucial. Recent studies have suggested that AML and CML may share common pathogenic mechanisms and cellular substrates. To this end, in the present study, global transcriptome profiles of AML and CML at the molecular and cellular level were directly compared using a combination of meta-analysis and modern statistics, and novel candidate genes and specific biological processes associated with the pathogenesis of AML and CML were characterized. Our study significantly improves our current understanding of myeloid leukemia and will help develop new therapeutic targets and biomarkers for disease progression, management and treatment response.

Abstract

Background: Acute myeloid leukemia (AML) and chronic myeloid leukemia (CML) represent a group of hematological malignancies characterized by the pathogenic clonal expansion of leukemic myeloid cells. The diagnosis and clinical outcome of AML and CML are complicated by genetic heterogeneity of disease; therefore, the identification of novel molecular biomarkers and pharmacological targets is of paramount importance. Methods: RNA-seq-based transcriptome data from a total of five studies were extracted from NCBI GEO repository and subjected to an in-depth bioinformatics analysis to identify differentially expressed genes (DEGs) between AML and CML. A systemic literature survey and functional gene ontology (GO) enrichment analysis were performed for the top 100 DEGs to identify novel candidate genes and biological processes associated with AML and CML. Results: LINC01554, PTMAP12, LOC644936, RPS27AP20 and FAM133CP were identified as novel risk genes for AML and CML. GO enrichment analysis showed that DEGs were significantly associated with pre-RNA splicing, reactive oxygen species and glycoprotein metabolism, the cellular endomembrane system, neutrophil migration and antimicrobial immune response. Conclusions: Our study revealed novel biomarkers and specific biological processes associated with AML and CML. Further studies are required to evaluate their value as molecular targets for managing and treating the myeloid malignancies.

Characterisation of the Circulating Transcriptomic Landscape in Inflammatory Bowel Disease Provides Evidence for Dysregulation of Multiple Transcription Factors Including NFE2, SPI1, CEBPB, and IRF2

AIM

To assess the pathobiological and translational importance of whole-blood transcriptomic analysis in inflammatory bowel disease [IBD].

METHODS

We analysed whole-blood expression profiles from paired-end sequencing in a discovery cohort of 590 Europeans recruited across six countries in the IBD Character initiative (newly diagnosed patients with Crohn's disease [CD; n = 156], ulcerative colitis [UC; n = 167], and controls [n = 267]), exploring differential expression [DESeq2], co-expression networks [WGCNA], and transcription factor involvement [EPEE, ChEA, DoRothEA]. Findings were validated by analysis of an independent replication cohort [99 CD, 100 UC, 95 controls]. In the discovery cohort, we also defined baseline expression correlates of future treatment escalation using cross-validated elastic-net and random forest modelling, along with a pragmatic ratio detection procedure.

RESULTS

Disease-specific transcriptomes were defined in IBD [8697 transcripts], CD [7152], and UC [8521], with the most highly significant changes in single genes, including CD177 (log2-fold change [LFC] = 4.63, p = 4.05 × 10-118), MCEMP1 [LFC = 2.45, p = 7.37 × 10-109], and S100A12 [LFC = 2.31, p = 2.15 × 10-93]. Significantly over-represented pathways included IL-1 [p = 1.58 × 10-11], IL-4, and IL-13 [p = 8.96 × 10-9]. Highly concordant results were obtained using multiple regulatory activity inference tools applied to the discovery and replication cohorts. These analyses demonstrated central roles in IBD for the transcription factors NFE2, SPI1 [PU.1], CEBPB, and IRF2, all regulators of cytokine signalling, based on a consistent signal across cohorts and transcription factor ranking methods. A number of simple transcriptome-based models were associated with the need for treatment escalation, including the binary CLEC5A/CDH2 expression ratio in UC (hazard ratio = 23.4, 95% confidence interval [CI] 5.3-102.0).

CONCLUSIONS

Transcriptomic analysis has allowed for a detailed characterisation of IBD pathobiology, with important potential translational implications.

Inhibition of BTK and PI3Kδ impairs the development of human JMML stem and progenitor cells

Juvenile myelomonocytic leukemia (JMML) is an aggressive myeloproliferative neoplasia that lacks effective targeted chemotherapies. Clinically, JMML manifests as monocytic leukocytosis, splenomegaly with consequential thrombocytopenia. Most commonly, patients have gain-of-function (GOF) oncogenic mutations in PTPN11 (SHP2), leading to Erk and Akt hyperactivation. Mechanism(s) involved in co-regulation of Erk and Akt in the context of GOF SHP2 are poorly understood. Here, we show that Bruton's tyrosine kinase (BTK) is hyperphosphorylated in GOF Shp2-bearing cells and utilizes B cell adaptor for PI3K to cooperate with p110δ, the catalytic subunit of PI3K. Dual inhibition of BTK and p110δ reduces the activation of both Erk and Akt. In vivo, individual targeting of BTK or p110δ in a mouse model of human JMML equally reduces monocytosis and splenomegaly; however, the combined treatment results in a more robust inhibition and uniquely rescues anemia and thrombocytopenia. RNA-seq analysis of drug-treated mice showed a profound reduction in the expression of genes associated with leukemic cell migration and inflammation, leading to correction in the infiltration of leukemic cells in the lung, liver, and spleen. Remarkably, in a patient derived xenograft model of JMML, leukemia-initiating stem and progenitor cells were potently inhibited in response to the dual drug treatment.

Gut microbiota composition in colorectal cancer patients is genetically regulated

The risk of colorectal cancer (CRC) depends on environmental and genetic factors. Among environmental factors, an imbalance in the gut microbiota can increase CRC risk. Also, microbiota is influenced by host genetics. However, it is not known if germline variants influence CRC development by modulating microbiota composition. We investigated germline variants associated with the abundance of bacterial populations in the normal (non-involved) colorectal mucosa of 93 CRC patients and evaluated their possible role in disease. Using a multivariable linear regression, we assessed the association between germline variants identified by genome wide genotyping and bacteria abundances determined by 16S rRNA gene sequencing. We identified 37 germline variants associated with the abundance of the genera Bacteroides, Ruminococcus, Akkermansia, Faecalibacterium and Gemmiger and with alpha diversity. These variants are correlated with the expression of 58 genes involved in inflammatory responses, cell adhesion, apoptosis and barrier integrity. Genes and bacteria appear to be involved in the same processes. In fact, expression of the pro-inflammatory genes GAL, GSDMD and LY6H was correlated with the abundance of Bacteroides, which has pro-inflammatory properties; abundance of the anti-inflammatory genus Faecalibacterium correlated with expression of KAZN, with barrier-enhancing functions. Both the microbiota composition and local inflammation are regulated, at least partially, by the same germline variants. These variants may regulate the microenvironment in which bacteria grow and predispose to the development of cancer. Identification of these variants is the first step to identifying higher-risk individuals and proposing tailored preventive treatments that increase beneficial bacterial populations.

Analysis of Keratinocytic Exosomes from Diabetic and Nondiabetic Mice by Charge Detection Mass Spectrometry

Unresolved inflammation compromises diabetic wound healing. Recently, we reported that inadequate RNA packaging in murine wound-edge keratinocyte-originated exosomes (Exoκ) leads to persistent inflammation [Zhou, X. ACS Nano 2020, 14(10), 12732-12748]. Herein, we use charge detection mass spectrometry (CDMS) to analyze intact Exoκ isolated from a 5 day old wound-edge tissue of diabetic mice and a heterozygous nondiabetic littermate control group. In CDMS, the charge (z) and mass-to-charge ratio (m/z) of individual exosome particles are measured simultaneously, enabling the direct analysis of masses in the 1-200 MDa range anticipated for exosomes. These measurements reveal a broad mass range for Exoκ from ∼10 to >100 MDa. The m and z values for these exosomes appear to fall into families (subpopulations); a statistical modeling analysis partially resolves ∼10-20 Exoκ subpopulations. Complementary proteomics, immunofluorescence, and electron microscopy studies support the CDMS results that Exoκ from diabetic and nondiabetic mice vary substantially. Subpopulations having high z (>650) and high m (>44 MDa) are more abundant in nondiabetic animals. We propose that these high m and z particles may arise from differences in cargo packaging. The veracity of this idea is discussed in light of other recent CDMS results involving genome packaging in vaccines, as well as exosome imaging experiments. Characterization of intact exosome particles based on the physical properties of m and z provides a new means of investigating wound healing and suggests that CDMS may be useful for other pathologies.

Immune Cell Plasticity in Inflammation: Insights into Description and Regulation of Immune Cell Phenotypes

Inflammation is a life-saving immune reaction occurring in response to invading pathogens. Nonetheless, inflammation can also occur in an uncontrolled, unrestricted manner, leading to chronic disease and organ damage. Mechanisms triggering an inflammatory response, hindering such a response, or leading to its resolution are well-studied but so far insufficiently elucidated with regard to precise therapeutic interventions. Notably, as an immune reaction evolves, requirements and environments for immune cells change, and thus cellular phenotypes adapt and shift, leading to the appearance of distinct cellular subpopulations with new functional features. In this article, we aim to highlight properties of, and overarching regulatory factors involved in, the occurrence of immune cell phenotypes with a special focus on neutrophils, macrophages and platelets. Additionally, we point out implications for both diagnostics and therapeutics in inflammation research.

Targeting of neutrophil activation in the early phase of the disease for prevention of Coronavirus disease-19 severity

The prevention of the disease severity seems critical for reducing the mortality of Coronavirus (CoV) disease‐19. The neutrophils play a key role in the induction of severity. It is proposed here that inhibition of neutrophil activation and/or cascade reactions of complement, leading to this cell activation at the early phase of the disease, is a potential tool to inhibit aggravation of the disease. The need for appropriate timing in intervention is emphasized as follows. (1) Intervention at the very early stage of severe acute respiratory syndrome‐CoV‐2 infection may harm the defensive host response to the infection because of the critical function of neutrophils in this response, and (2) intervention at too late a stage will not stop the infiltration of fully activated neutrophils that produce large amounts of toxic substances.

Enhanced Migratory Ability of Neutrophils Toward Epidermis Contributes to the Development of Psoriasis via Crosstalk With Keratinocytes by Releasing IL-17A

Microabscess of neutrophils in epidermis is one of the histological hallmarks of psoriasis. The axis of neutrophil–keratinocyte has been thought to play a critical role in the pathogenesis of psoriasis. However, the features and mechanism of interaction between the two cell types remain largely unknown. Herein, we found that blood neutrophils were increased in psoriasis patients, positively correlated with disease severity and highly expressed CD66b, but not CD11b and CD62L compared to healthy controls. Keratinocytes expressed high levels of psoriasis-related inflammatory mediators by direct and indirect interaction with neutrophils isolated from psoriasis patients and healthy controls. The capacity of neutrophils in provoking keratinocytes inflammatory response was comparable between the two groups and is dependent on IL-17A produced by itself. Neutrophils isolated from psoriasis patients displayed more transcriptome changes related to integrin and increased migration capacity toward keratinocytes with high CD11b expression on cell surface. Of interest, neutrophils were more susceptible to keratinocyte stimulation than to fibroblasts and human umbilical vein endothelial cells (HUVECs) in terms of CD11b expression and the production of ROS and NETs. In conclusion, neutrophils from psoriasis patients gain a strong capacity of IL-17A production and integrins expression that possibly facilitates their abilities to promote production of psoriasis-related inflammatory mediators and migration, a phenomenon likely induced by their interaction with keratinocytes but not with fibroblasts. These findings provide a proof-of-concept that development of new drugs targeting migration of neutrophils could be a more specific and safe solution to treat psoriasis.

Ageing and interferon gamma response drive the phenotype of neutrophils in the inflamed joint

OBJECTIVE

Neutrophils are typically the most abundant leucocyte in arthritic synovial fluid. We sought to understand changes that occur in neutrophils as they migrate from blood to joint.

METHODS

We performed RNA sequencing of neutrophils from healthy human blood, arthritic blood and arthritic synovial fluid, comparing transcriptional signatures with those from murine K/BxN serum transfer arthritis. We employed mass cytometry to quantify protein expression and sought to reproduce the synovial fluid phenotype ex vivo in cultured healthy blood neutrophils.

RESULTS

Blood neutrophils from healthy donors and patients with active arthritis showed largely similar transcriptional signatures. By contrast, synovial fluid neutrophils exhibited more than 1600 differentially expressed genes. Gene signatures identified a prominent response to interferon gamma (IFN-γ), as well as to tumour necrosis factor, interleukin-6 and hypoxia, in both humans and mice. Mass cytometry confirmed that healthy and arthritic donor blood neutrophils are largely indistinguishable but revealed a range of neutrophil phenotypes in synovial fluid defined by downregulation of CXCR1 and upregulation of FcγRI, HLA-DR, PD-L1, ICAM-1 and CXCR4. Reproduction of key elements of this signature in cultured blood neutrophils required both IFN-γ and prolonged culture.

CONCLUSIONS

Circulating neutrophils from patients with arthritis resemble those from healthy controls, but joint fluid cells exhibit a network of changes, conserved across species, that implicate IFN-γ response and ageing as complementary drivers of the synovial fluid neutrophil phenotype.