Monocytes, macrophages, dendritic cells and neutrophils: an update on lifespan kinetics in health and disease

Naples Prognostic Score (NPS) as a Novel Prognostic Score for Stage III Breast Cancer Patients: A Real-World Retrospective Study

Objective

This study aims to explore whether Naples prognostic score (NPS) serves as a novel and original prognostic tool for predicting long-term survival in stage III breast cancer patients undergoing operation.

Methods

This retrospective study included 306 cases of stage III breast cancer patients hospitalized in our hospital from January 2014 to December 2018. In this study, NPS was based on five objective markers: (1) serum albumin level; (2) total cholesterol; (3) neutrophil to lymphocyte ratio; (4) lymphocyte to monocyte ratio. Survival curves of DFS and OS differences were visualized by Kaplan-Meier method and Log rank test. The variables with p < 0.05 in univariate analysis were performed in the multivariate Cox proportional hazard model analysis, and the p-values < 0.05 was considered the underlying independent variables. Nomogram was constructed by the multivariate Cox proportional hazard model analysis.

Results

Significant variations for DFS and OS categorized according to prognostic risk for the different NPS (DFS: χ2=24.926, P < 0.0001; OS: χ2=31.207, P < 0.0001). According to multivariable Cox analysis, NPS was an independent prognostic factor of DFS [Group 0 had significantly better prognosis than group 1 (HR = 2.733, 95% CI: 1.446-5.166, P = 0.002) and group 2 (HR = 4.990, 95% CI: 2.555-9.746), P < 0.001)] and OS [Group 0 had significantly better prognosis than group 1 (HR = 2.437, 95% CI: 1.288-4.610, P = 0.006) and group 2 (HR = 5.707, 95% CI: 2.900-11.231), P < 0.001)], respectively. Nomogram prognostic model exhibited excellent predictive performance on DFS [C-index: 0.692 (95% CI: 0.584-0.782)] and OS [C-index: 0.711 (95% CI: 0.606-0.797)] for stage III breast cancer.

Conclusion

NPS serves as a predictive tool for assessing the prognosis of stage III breast cancer after surgery. Nomogram prognostic model based on NPS show good prediction ability.

Uncovering the impact of infection routes on within-host MPXV dynamics: Insights from a mathematical modeling study

The unprecedented mpox outbreak in non-endemic regions during 2022-2023, which has seen a recent resurgence in late 2023-2024, poses a significant public health threat. Despite its global spread, the viral dynamics of mpox infection and the specific characteristics driving these outbreaks remain insufficiently explored. We develop mathematical models to examine the interactions between host immune responses and the virus across three distinct infection routes (intravenous, intradermal, and intrarectal). The models are calibrated using viral load data from macaques infected through each of these three infection routes. Subsequently, we calculate the infectiousness of each infected macaque, finding that the proportion of presymptomatic infectiousness is highest in those infected via sexual contact, followed by skin-to-skin contact. These observations demonstrate that close contact during sexual activity is a significant route of viral transmission, with presymptomatic spread playing a crucial role in the 2022-2023 multi-country outbreak and potentially also in the 2023-2024 multi-source outbreak. Leveraging model predictions and infectiousness data, we assess the impact of antiviral drugs on interventions against mpox infection. Model simulations suggest that early administration of antiviral drugs can reduce peak viral loads, even in individuals with compromised immunity, particularly in cases of infection through skin-to-skin and sexual contact. These results underscore the importance of initiating antiviral treatment as early as possible for mpox-infected patients with compromised immune systems, such as those who are HIV-positive.

Immunomodulatory effects of calorie restriction and its mimetics: A new potential therapeutic approach for autoimmune diseases

Calorie restriction (CR) is a well known intervention associated with multifaceted anti-aging and pro-longevity health benefits. It induces complex physiological cellular and molecular adaptations, resulting in the fine-tuning of metabolic and immune responses in both homeostatic and diseased states. It has thus been extensively studied both preclinically and clinically, uncovering its therapeutic potential against inflammatory conditions, particularly autoimmune diseases. CR mimetics (CRMs), that is, molecules that mimic CR's effects, have also been widely investigated to counteract inflammatory states associated with numerous diseases, including autoimmunity. However, a comprehensive overview of how CR and CRMs modulate different aspects of immune responses, thereby potentially modifying autoimmunity, is still lacking. Here, we reviewed the latest progress on the impacts of CR and CRMs on the immune system and the current evidence on their potential translation in the clinical management of people with autoimmune diseases. First, we summarized different types of CR and CRMs and their main mechanisms of action. We next reviewed comprehensively how CR and CRMs modulate immune cells and discussed up-to-date preclinical and clinical advances in using CR and CRMs in the context of some of the most common autoimmune diseases. Finally, challenges faced in CR-related research and its translation into the clinic are discussed. SIGNIFICANCE STATEMENT: Calorie restriction (CR) encompasses various approaches for daily or intermittent reduction in calorie intake while maintaining adequate nutrient intake. It acts through cell-intrinsic and -extrinsic pathways to modulate immune cell functions. CR is emerging as a strategy for autoimmune disease management. CR's effects could be partially mimicked by molecules called CR mimetics, which are proposed to achieve CR's effects without reducing food intake. CR and CR mimetics have been tested as promising potential therapeutics in preclinical and clinical autoimmune disease studies.

Prolonging neutrophil room-temperature storage with clinically approved solutions: implications for granulocyte transfusion

Granulocyte concentrates (GCs) are leukocyte preparations enriched in neutrophils that can potentially save neutropenic patients from life-threatening, antimicrobial-resistant infections. The main challenge of GC transfusions is preserving the viability and antimicrobial activity of neutrophils beyond 24 h to reduce the logistical burden on collection centers and increase the availability of this cell therapy. Thus, the aim of this study was to explore extending the ex vivo viability and antimicrobial activity of GC neutrophils up to 72 h with a unique combination of the clinically approved additives Plasma-Lyte (PL), SAGM, AS-3, and Alburex. Neutrophils isolated from healthy donors were resuspended in autologous plasma at the same concentration as in GCs, diluted with various combinations of PL, SAGM, AS-3, and/or Alburex with or without the addition of buffers, and stored at room temperature for up to 72 h. During storage, neutrophil viability, phagocytosis, and intracellular reactive oxygen species production were measured by flow cytometry. Extracellular reactive oxygen species production was measured by spectrophotometry and chemotaxis by the number of calcein-stained neutrophils that migrated toward the chemotactic peptide, N-formyl-Met-Leu-Phe (fMLF). The same assays were performed on pooled, residual leukocyte units generated by the Reveos system, after storage in the additive combination that most effectively preserved the viability and function of isolated neutrophils. The additive combination that best performed in the majority of the assays contained PL, buffers, and AS-3. Neutrophil viability was preserved for a maximum of 48 h and phagocytosis of opsonized bacteria and reactive oxygen species production up to 72 h of storage at room temperature. In contrast, fMLF-induced chemotaxis decreased by 20% after 24-h storage while extracellular reactive oxygen species production increased significantly within the same time period. Supplementing GCs prepared from pooled, residual leukocyte units with this storage solution after the standard 16- to 24-h processing period as per the blood center guidelines, did not significantly improve the preservation of neutrophil viability and function. Our findings provide proof of concept that mixtures of clinically approved additives can be tailored to significantly prolong the viability and function of freshly isolated neutrophils during room-temperature storage. The unique additive composition of this storage solution that we developed for freshly isolated neutrophils requires further optimization for use with pooled, residual leukocyte units as well as the timepoint at which the solution is added during processing to prolong the viability and functions of neutrophils in this blood product.

Mass cytometric analysis of circulating monocyte subsets in a murine model of diabetic gastroparesis

Circulating monocytes (Mo) are precursors to a subset of gastric resident muscularis macrophages. Changes in muscularis macrophages (MMs) result in delayed gastric emptying (DGE) in diabetic gastroparesis. However, the dynamics of Mo in the development of DGE in an animal model are unknown. Using cytometry by time-of-flight and computational approaches, we show a high heterogeneity within the Mo population. In DGE mice, via unbiased clustering, we identified two reduced Mo clusters that exhibit migratory phenotype (Ly6ChiCCR2hi-intCD62LhiLy6GhiCD45RhiMERTKhiintLGALS3intCD14intCX3CR1lowSiglec-Hint-low) resembling classical Mo (CMo-like). All markers enriched in these clusters are known to regulate cell differentiation, proliferation, adhesion, and migration. Trajectory inference analysis predicted these Mo as precursors to subsequent Mo lineages. In gastric muscle tissue, we demonstrated an increase in the gene expression levels of chemokine receptor C-C chemokine receptor type 2 (Ccr2) and its C-C motif ligand 2 (Ccl2), suggesting increased trafficking of classical-Mo. These findings establish a link between two CMo-like clusters and the development of the DGE phenotype and contribute to a better understanding of the heterogenicity of the Mo population.NEW & NOTEWORTHY Using 32 immune cell surface markers, we identified 23 monocyte clusters in murine blood. Diabetic gastroparesis was associated with a significant decrease in two circulating classical monocyte-like clusters and an upregulation of the Ccr2-Ccl2 axis in the gastric muscularis propria, suggesting increased tissue monocyte migration. This study offers new targets by pointing to a possible role for two classical monocyte subsets connected to the Ccr2-Ccl2 axis.

Mathematical modeling unveils the timeline of CAR-T cell therapy and macrophage-mediated cytokine release syndrome

Chimeric antigen receptor (CAR)-T cell therapy holds significant potential for cancer treatment, although disease relapse and cytokine release syndrome (CRS) remain as frequent clinical challenges. To better understand the mechanisms underlying the temporal dynamics of CAR-T cell therapy response and CRS, we developed a novel multi-layer mathematical model incorporating antigen-mediated CAR-T cell expansion, antigen-negative resistance, and macrophage-associated cytokine release. Three key mechanisms of macrophage activation are considered: release of damage-associated molecular patterns, antigen-binding mediated activation, and CD40-CD40L contact. The model accurately describes 25 patient time courses with different responses and IL-6 cytokine kinetics. We successfully link the dynamic shape of the response to interpretable model parameters and investigate the influence of CAR-T cell dose and initial tumor burden on the occurrence of cytokine release and treatment outcome. By disentangling the timeline of macrophage activation, the model identified distinct contributions of each activation mechanism, suggesting the CD40-CD40L axis as a major driver of cytokine release and a clinically feasible target to control the activation process and modulate cytokine peak height. Our multi-layer model provides a comprehensive framework for understanding the complex interactions between CAR-T cells, tumor cells, and macrophages during therapy.

Systems Human Immunology and AI: Immune Setpoint and Immune Health

The immune system, critical for human health and implicated in many diseases, defends against pathogens, monitors physiological stress, and maintains tissue and organismal homeostasis. It exhibits substantial variability both within and across individuals and populations. Recent technological and conceptual progress in systems human immunology has provided predictive insights that link personal immune states to intervention responses and disease susceptibilities. Artificial intelligence (AI), particularly machine learning (ML), has emerged as a powerful tool for analyzing complex immune data sets, revealing hidden patterns across biological scales, and enabling predictive models for individualistic immune responses and potentially personalized interventions. This review highlights recent advances in deciphering human immune variation and predicting outcomes, particularly through the concepts of immune setpoint, immune health, and use of the immune system as a window for measuring health. We also provide a brief history of AI; review ML modeling approaches, including their applications in systems human immunology; and explore the potential of AI to develop predictive models and personal immune state embeddings to detect early signs of disease, forecast responses to interventions, and guide personalized health strategies.

Neutrophil-modulated Dicer expression in macrophages influences inflammation resolution

The precise molecular mechanisms through which neutrophils regulate macrophages in the progression and resolution of acute inflammation remain poorly understood. Here, we present new findings on the role of Dicer in regulating macrophage phenotypic transitions essential for proper inflammatory progression and resolution, influenced by neutrophils. Using a zymosan A (Zym A)-induced self-limited mouse peritonitis model, we observed that Dicer expression in macrophages was significantly reduced by neutrophil-derived IFN-γ during the progression phase, but gradually returned to normal levels during the resolution phase following the engulfment of apoptotic neutrophils. Our study on macrophage-specific Dicer1-depletion (Dicer1-CKO) mice demonstrated that inflammation in these mice was more severe during the progression phase, characterized by increased pro-inflammatory cytokines and enhanced neutrophil trafficking. Additionally, resolution was impaired in Dicer1-CKO mice, leading to the accumulation of uncleared apoptotic neutrophils. Specifically, the absence of Dicer in macrophages resulted in M1 polarization and heightened bactericidal activity, facilitating the progression of acute inflammation. Conversely, inducing Dicer expression promoted macrophage transition to M2 polarization, enhancing apoptotic cell clearance and expediting the resolution of inflammation. Our findings suggest that Dicer plays a central role in regulating the progression and resolution of acute inflammation, with implications for the treatment of inflammatory diseases.

Neutrophil Heterogeneity in Wound Healing

Neutrophils are the most abundant type of immune cells and also the most underestimated cell defenders in the human body. In fact, their lifespan has also been extensively revised in recent years, going from a half-life of 8-10 h to a longer lifespan of up to 5.4 days in humans; it has been discovered that their mechanisms of defense are multiple and finely modulated, and it has been suggested that the heterogeneity of neutrophils occurs as well as in other immune cells. Neutrophils also play a critical role in the wound healing process, and their involvement is not limited to the initial stages of defense against pathogens, but extends to the inflammatory phase of tissue reconstruction. Neutrophil heterogeneity has recently been reported at the presence of distinct subtypes expressing different functional states, which contribute uniquely to the different phases of innate immunity and wound healing. This heterogeneity can be induced by the local microenvironment, by the presence of specific cytokines and by the type of injury. The different functional states of neutrophils enable a finely tuned response to injury and stress, which is essential for effective healing. Understanding the functional heterogeneity of neutrophils in wound healing can unveil potential pathological profiles and therapeutic targets. Moreover, the understanding of neutrophil heterogeneity dynamics could help in designing strategies to manage excessive inflammation or impaired healing processes. This review highlights the complexity of neutrophil heterogeneity and its critical roles throughout the phases of wound healing.

Imaging Flow Cytometry in HIV Infection Research: Advantages and Opportunities

The human immunodeficiency virus (HIV) is a type of retrovirus that infects humans and belongs to the Lentivirus group. Despite the availability of effective treatments, HIV infections are still increasing in some parts of the world, according to the World Health Organization (WHO). Another major challenge is the growing problem of HIV becoming resistant to drugs. This highlights the importance of ongoing research to better understand HIV and find new ways to stop the virus from spreading in the body. Scientists use a variety of methods to study HIV, including techniques from molecular and cellular biology. Many of these methods rely on fluorescent dyes to help visualize specific parts of the virus or infected cells. This article focuses on a technique called imaging flow cytometry, which is particularly useful for studying HIV. Imaging flow cytometry is unique because it not only measures fluorescence (light emitted by the dyes) but also captures images of each cell being analyzed. This allows researchers to see where the fluorescence is located within the cell and to study the cell's shape and structure in detail. Additionally, this method can be combined with machine learning to analyze large amounts of data more efficiently.

Acute Severe Hypoxia Decreases Mitochondrial Chain Complex II Respiration in Human Peripheral Blood Mononuclear Cells

Peripheral blood mononuclear cells' (PBMCs) mitochondrial respiration is impaired and likely involved in myocardial injury and heart failure pathophysiology, but its response to acute and severe hypoxia, often associated with such diseases, is largely unknown in humans. We therefore determined the effects of acute hypoxia on PBMC mitochondrial respiration and ROS production in healthy volunteers exposed to controlled oxygen reduction, achieving an inspired oxygen fraction of 10.5%. We also investigated potential relationships with gene expression of key biomarkers of hypoxia, succinate and inflammation, as hypoxia and inflammation share common mechanisms involved in cardiovascular disease. Unlike global mitochondrial respiration, hypoxemia with a spO2 ≤ 80% significantly reduced PBMC complex II respiration (from 6.5 ± 1.2 to 3.1 ± 0.5 pmol/s/106 cell, p = 0.04). Complex II activity correlated positively with spO2 (r = 0.63, p = 0.02) and inversely correlated with the succinate receptor SUCNR1 (r = -0.68), the alpha-subunit of the hypoxia-inducible factor (HIF-1α, r = -0.61), the chemokine ligand-9 (r = -0.68) and interferon-stimulated gene 15 (r = -0.75). In conclusion, severe hypoxia specifically impairs complex II respiration in association with succinate, inflammation and HIF-1α pathway interactions in human PBMCs. These results support further studies investigating whether modulation of complex II activity might modify the inflammatory and metabolic alterations observed in heart failure.

Complete Blood Cell Count-Based Ratios Identify Total Joint Arthroplasty Patients Likely to Benefit from Perioperative Dexamethasone

BACKGROUND

Complete blood cell count-based ratios (CBRs), including the neutrophil-lymphocyte ratio (NLR) and monocyte-lymphocyte ratio (MLR), are inflammatory markers associated with postoperative morbidity. Given the link between the surgical stress response and complications after total joint arthroplasty (TJA), this study aimed to evaluate whether higher preoperative CBR values predict greater postoperative benefits associated with dexamethasone utilization.

METHODS

The Premier Healthcare Database was queried for adult patients who underwent primary, elective total hip or knee arthroplasty (THA or TKA). Multivariable logistic regression models using dexamethasone exposure and CBRs as independent variables assessed primary end points of 90-day postoperative complications and length of stay (LOS) of ≥3 days. The probability difference between the dexamethasone and non-dexamethasone groups for each primary end point was determined across all values of each CBR. Probability differences were compared across CBR quartiles.

RESULTS

A total of 32,849 primary, elective TJAs (12,788 THAs [38.93%], 20,061 TKAs [61.07%]) performed between 2016 and 2021 were identified, and 22,282 (67.83%) of the patients received perioperative dexamethasone. Among patients with an NLR value of >1.00, those receiving dexamethasone had a lower probability of postoperative complications (all p < 0.05). Dexamethasone was associated with lower odds of an LOS of ≥3 days among patients in the highest NLR quartile (≥4.67) compared with the lowest quartile (NLR <1.84) (p = 0.002). Among patients with an MLR value of ≥0.36, those receiving dexamethasone had significantly lower odds of postoperative complications. Dexamethasone was associated with lower odds of an LOS of ≥3 days among patients with an MLR of ≥0.33 (the 2 highest quartiles) compared with an MLR of <0.24 (the lowest quartile) (p = 0.039).

CONCLUSIONS

Higher NLR and MLR values were associated with greater marginal benefit from perioperative dexamethasone treatment, establishing a modifiable link between adverse outcomes and perioperative inflammation in TJA.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Role of Chronic Inflammation in Pediatric Cancer

Inflammation plays a crucial role in wound healing and the host immune response following pathogenic invasion. However, unresolved chronic inflammation can result in tissue fibrosis and genetic alterations that contribute to the pathogenesis of human diseases such as cancer. Recent scientific advancements exploring the underlying mechanisms of malignant cellular transformations and cancer progression have exposed significant disparities between pediatric and adult-onset cancers. For instance, pediatric cancers tend to have lower mutational burdens and arise in actively developing tissues, where cell-cycle dysregulation leads to gene, chromosomal, and fusion gene development not seen in adult-onset counterparts. As such, scientific findings in adult cancers cannot be directly applied to pediatric cancers, where unique mutations and inherent etiologies remain poorly understood. Here, we review the role of chronic inflammation in processes of genetic and chromosomal instability, the tumor microenvironment, and immune response that result in pediatric tumorigenesis transformation and explore current and developing therapeutic interventions to maintain and/or restore inflammatory homeostasis.

Guidelines for preparation and flow cytometry analysis of human nonlymphoid tissue DC

This article is part of the Dendritic Cell Guidelines article series, which provides a collection of state-of-the-art protocols for the preparation, phenotype analysis by flow cytometry, generation, fluorescence microscopy, and functional characterization of mouse and human dendritic cells (DC) from lymphoid organs, and various nonlymphoid tissues. Within this article, detailed protocols are presented that allow for the generation of single-cell suspensions from human nonlymphoid tissues including lung, skin, gingiva, intestine as well as from tumors and tumor-draining lymph nodes with a subsequent analysis of dendritic cells by flow cytometry. Further, prepared single-cell suspensions can be subjected to other applications including cellular enrichment procedures, RNA sequencing, functional assays, etc. While all protocols were written by experienced scientists who routinely use them in their work, this article was also peer-reviewed by leading experts and approved by all co-authors, making it an essential resource for basic and clinical DC immunologists.

Deciphering infectious uveitis etiology: Immune cell profiling in keratic precipitates using in vivo confocal microscopy

Purpose

To elucidate the etiology of infectious uveitis through the comprehensive analysis of keratic precipitates (KPs) using in vivo confocal microscopy (IVCM).

Design

Cross-sectional, observational case series.

Methods

This single-center, cross-sectional study was conducted at a tertiary care eye hospital from January 2021 to October 2023. It involved a detailed ophthalmologic evaluation of all subjects and included a total of 46 eyes from 36 subjects who were diagnosed with infectious uveitis. IVCM, specifically utilizing the HRT II Rostock corneal module, was employed to study the biomicroscopic morphology of KPs. The categorization of KPs was based on cell size, morphology, and reflection.

Results

Cells of KPs were assessed for size, morphology, and reflection through in vivo confocal microscopy. Patients, ranging in age from 13 to 80 years (median 51 years), exhibited diverse morphologic forms of KPs. Neutrophil-dominated KPs with uniform size were predominantly observed in bacterial and fungal endophthalmitis cases (19/19, 100 %), accompanied by small numbers of mononuclear-macrophages in three eyes (3/19, 15.8 %). Viral uveitis cases displayed a broader array of immune cell types, including characteristic striated or dendritic cells in all eyes (27/27, 100 %). Lymphocytes were commonly present (24/27, 88.9 %), forming clusters in sixteen eyes and dispersed in the corneal endothelium below the midline in eight eyes. Neutrophil infiltration was notable in three cytomegalovirus-infected eyes (3/27, 11.1 %). A marked increase in sub-basal corneal epithelial Langhans cells was associated with viral uveitis.

Conclusions

Neutrophil-dominated KPs strongly indicate endogenous bacterial or fungal endophthalmitis, while the presence of dendritic cells and lymphocytes in KPs is suggestive of viral uveitis. In vivo confocal microscopy emerges as a crucial tool for differentiating the etiologic diagnosis of infectious uveitis.

The lifespan and kinetics of human dendritic cell subsets and their precursors in health and inflammation

Dendritic cells (DC) are specialized mononuclear phagocytes that link innate and adaptive immunity. They comprise two principal subsets: plasmacytoid DC (pDC) and conventional DC (cDC). Understanding the generation, differentiation, and migration of cDC is critical for immune homeostasis. Through human in vivo deuterium-glucose labeling, we observed the rapid appearance of AXL+ Siglec6+ DC (ASDC) in the bloodstream. ASDC circulate for ∼2.16 days, while cDC1 and DC2 circulate for ∼1.32 and ∼2.20 days, respectively, upon release from the bone marrow. Interestingly, DC3, a cDC subset that shares several similarities with monocytes, exhibits a labeling profile closely resembling that of DC2. In a human in vivo model of cutaneous inflammation, ASDC were recruited to the inflammatory site, displaying a distinctive effector signature. Taken together, these results quantify the ephemeral circulating lifespan of human cDC and propose functions of cDC and their precursors that are rapidly recruited to sites of inflammation.

High Silent Prevalence of Zinc Deficiency and Impaired Immunity in Children Under Five Years of Age Admitted to a Regional Referral Hospital in Uganda

Introduction Zinc deficiency (ZnD) impairs the development of acquired immunity and contributes to growth failure in children under five years of age. However, the prevalence of ZnD and its association with immunity in this age group in Uganda have not been well explored. This study aimed to determine the prevalence of ZnD and explore the associations between low serum zinc levels and total white blood cell count, differential cell counts, and levels of IL-1 and IL-2 in children aged 12 to 59 months. Methods In this cross-sectional study, we enrolled children aged 12 to 59 months upon admission to the pediatrics ward of Masaka Regional Referral Hospital (MRRH), located in Masaka City, Southern Uganda. Anthropometric measurements were taken and interpreted using the WHO growth standards charts for age and sex. Whole blood cell counts, serum zinc levels, CRP, and IL-2 and IL-4 were measured. Student's t-test, Mann-Whitney test, and correlation coefficients were used to assess relationships between variables. Results A total of 40 children (mean age 27.8 (SD 10.6) months; 50% boys) were enrolled. Nearly a third (13/40) of the children were malnourished (22.5% stunted and 12.5% wasted), and 82.5% had anemia (Hb <11.0 g/dL). The prevalence of ZnD was 40.6%. Serum zinc levels showed a positive correlation with total white blood cell count (rs = 0.41, p = 0.02) and lymphocyte count (rs = 0.43, p = 0.01). However, no association was found between ZnD and levels of IL-2 or IL-4. Conclusions The study revealed a high prevalence of ZnD, with serum zinc levels correlating with both total white blood cell and T cell counts, but not with IL-2 levels, in children under five years of age at the time of admission. We recommend the routine inclusion of ZnD assessment and treatment in the care of sick children in the region. Additionally, a larger multicenter longitudinal study is needed to further evaluate the association between malnutrition and health outcomes in this age group.

Donor-Specific Blood Transfusion in Lung Transplantation

Lung transplantation is still hindered by a high rate of chronic rejection necessitating profound immunosuppression with its associated complications. Donor-specific blood transfusion is a pre-transplant strategy aimed at improving graft acceptance. In contrast with standard stored blood or donor-specific regulatory T cells transfusions, this approach utilizes fresh whole blood from the donor prior to allograft transplantation, encompassing all cell types and plasma. The precise mechanisms underlying donor-specific blood transfusion-induced tolerance remain incompletely understood. Associations with regulatory/helper T cells, modulation of mononuclear phagocytic cells or microchimerism have been suggested. While numerous (pre-)clinical studies have explored its application in solid organ transplants like liver, kidney, and intestine, limited attention has been given to the setting of lung transplantation. This comprehensive review summarizes existing knowledge on the mechanisms and outcomes of donor-specific blood transfusion in solid organ transplants both in preclinical and clinical settings. We also address the potential benefits and risks associated with donor-specific blood transfusion in the field of lung transplantation, offering insights into future research directions.

Leishmania major surface components and DKK1 signalling via LRP6 promote migration and longevity of neutrophils in the infection site

Background

Host-related factors highly regulate the increased circulation of neutrophils during Leishmania infection. Platelet-derived Dickkopf-1 (DKK1) is established as a high-affinity ligand to LRP6. Recently, we demonstrated that DKK1 upregulates leukocyte-platelet aggregation, infiltration of neutrophils to the draining lymph node and Th2 differentiation during Leishmania infection, suggesting the potential involvement of the DKK1-LRP6 signalling pathway in neutrophil migration in infectious diseases.

Results

In this study, we further explored the potential role of DKK1-LRP6 signalling in the migration and longevity of activated neutrophils in the infection site using BALB/c mice with PMNs deficient in LRP6 (LRP6NKO) or BALB/c mice deficient in both PMN LRP6 and platelet DKK1 (LRP6NKO DKK1PKO). Relative to the infected wild-type BALB/c mice, reduced neutrophil activation at the infection site of LRP6NKO or LRP6NKO DKK1PKO mice was noted. The neutrophils obtained from either infected LRP6NKO or LRP6NKO DKK1PKO mice additionally showed a high level of apoptosis. Notably, the level of LRP6 expressing neutrophils was elevated in infected BALB/c mice. Relative to infected BALB/c mice, a significant reduction in parasite load was observed in both LRP6NKO and LRP6NKO DKK1PKO infected mice. Notably, DKK1 levels were comparable in the LRP6NKO and BALB/c mice in response to infection, indicating that PMN activation is the major pathway for DKK1 in promoting parasitemia. Parasite-specific components also play a crucial role in modulating neutrophil circulation in Leishmania disease. Thus, we further determine the contribution of Leishmania membrane components in the migration of neutrophils to the infection site using null mutants deficient in LPG synthesis (Δlpg1- ) or lacking all ether phospholipids (plasmalogens, LPG, and GIPLs) synthesis (Δads1- ). Relative to the WT controls, Δads1- parasite-infected mice showed a sustained decrease in neutrophils and neutrophil-platelet aggregates (for at least 14 days PI), while neutrophils returned to normal in Δlpg1- parasite-infected mice after day 3 PI.

Conclusion

Our results suggest that DKK1 signalling and Leishmania pathogen-associated molecular patterns appear to regulate the migration and sustenance of viable activated neutrophils in the infection site resulting in chronic type 2 cell-mediated inflammation.

Cell-surface Milieu Remodeling in Human Dendritic Cell Activation

Dendritic cells (DCs) are specialized sentinel and APCs coordinating innate and adaptive immunity. Through proteins on their cell surface, DCs sense changes in the environment, internalize pathogens, present processed Ags, and communicate with other immune cells. By combining chemical labeling and quantitative mass spectrometry, we systematically profiled and compared the cell-surface proteomes of human primary conventional DCs (cDCs) in their resting and activated states. TLR activation by a lipopeptide globally reshaped the cell-surface proteome of cDCs, with >100 proteins upregulated or downregulated. By simultaneously elevating positive regulators and reducing inhibitory signals across multiple protein families, the remodeling creates a cell-surface milieu promoting immune responses. Still, cDCs maintain the stimulatory-to-inhibitory balance by leveraging a distinct set of inhibitory molecules. This analysis thus uncovers the molecular complexity and plasticity of the cDC cell surface and provides a roadmap for understanding cDC activation and signaling.

Advances and applications of biomimetic biomaterials for endogenous skin regeneration

Endogenous regeneration is becoming an increasingly important strategy for wound healing as it facilitates skin's own regenerative potential for self-healing, thereby avoiding the risks of immune rejection and exogenous infection. However, currently applied biomaterials for inducing endogenous skin regeneration are simplistic in their structure and function, lacking the ability to accurately mimic the intricate tissue structure and regulate the disordered microenvironment. Novel biomimetic biomaterials with precise structure, chemical composition, and biophysical properties offer a promising avenue for achieving perfect endogenous skin regeneration. Here, we outline the recent advances in biomimetic materials induced endogenous skin regeneration from the aspects of structural and functional mimicry, physiological process regulation, and biophysical property design. Furthermore, novel techniques including in situ reprograming, flexible electronic skin, artificial intelligence, single-cell sequencing, and spatial transcriptomics, which have potential to contribute to the development of biomimetic biomaterials are highlighted. Finally, the prospects and challenges of further research and application of biomimetic biomaterials are discussed. This review provides reference to address the clinical problems of rapid and high-quality skin regeneration.

The assembly of neutrophil inflammasomes during COVID-19 is mediated by type I interferons

The severity of COVID-19 is linked to excessive inflammation. Neutrophils represent a critical arm of the innate immune response and are major mediators of inflammation, but their role in COVID-19 pathophysiology remains poorly understood. We conducted transcriptomic profiling of neutrophils obtained from patients with mild and severe COVID-19, as well as from SARS-CoV-2 infected mice, in comparison to non-infected healthy controls. In addition, we investigated the inflammasome formation potential in neutrophils from patients and mice upon SARS-CoV-2 infection. Transcriptomic analysis of polymorphonuclear cells (PMNs), consisting mainly of mature neutrophils, revealed a striking type I interferon (IFN-I) gene signature in severe COVID-19 patients, contrasting with mild COVID-19 and healthy controls. Notably, low-density granulocytes (LDGs) from severe COVID-19 patients exhibited an immature neutrophil phenotype and lacked this IFN-I signature. Moreover, PMNs from severe COVID-19 patients showed heightened nigericin-induced caspase1 activation, but reduced responsiveness to exogenous inflammasome priming. Furthermore, IFN-I emerged as a priming stimulus for neutrophil inflammasomes. These findings suggest a potential role for neutrophil inflammasomes in driving inflammation during severe COVID-19. Altogether, these findings open promising avenues for targeted therapeutic interventions to mitigate the pathological processes associated with the disease.

Endothelial and macrophage interactions in the angiogenic niche

The interactions between vascular cells, especially endothelial cells, and macrophages play a pivotal role in maintaining the subtle balance of vascular biology, which is crucial for angiogenesis in both healthy and diseased states. These cells are central to ensuring a harmonious balance between tissue repair and preventing excessive angiogenic activity, which could lead to pathological conditions. Recent advances in sophisticated genetic engineering vivo models and novel sequencing approaches, such as single-cell RNA-sequencing, in immunobiology have significantly enhanced our understanding of the gene expression and behavior of macrophages. These insights offer new perspectives on the role macrophages play not only in development but also across various health conditions. In this review, we explore the complex interactions between multiple types of macrophages and endothelium, focusing on their impact on new blood vessel formation. By understanding these intricate interactions, we aim to provide insights into new methods for managing angiogenesis in various diseases, thereby offering hope for the development of novel therapeutic approaches.

Profound Properties of Protein-Rich, Platelet-Rich Plasma Matrices as Novel, Multi-Purpose Biological Platforms in Tissue Repair, Regeneration, and Wound Healing

Autologous platelet-rich plasma (PRP) preparations are prepared at the point of care. Centrifugation cellular density separation sequesters a fresh unit of blood into three main fractions: a platelet-poor plasma (PPP) fraction, a stratum rich in platelets (platelet concentrate), and variable leukocyte bioformulation and erythrocyte fractions. The employment of autologous platelet concentrates facilitates the biological potential to accelerate and support numerous cellular activities that can lead to tissue repair, tissue regeneration, wound healing, and, ultimately, functional and structural repair. Normally, after PRP preparation, the PPP fraction is discarded. One of the less well-known but equally important features of PPP is that particular growth factors (GFs) are not abundantly present in PRP, as they reside outside of the platelet alpha granules. Precisely, insulin-like growth factor-1 (IGF-1) and hepatocyte growth factor (HGF) are mainly present in the PPP fraction. In addition to their roles as angiogenesis activators, these plasma-based GFs are also known to inhibit inflammation and fibrosis, and they promote keratinocyte migration and support tissue repair and wound healing. Additionally, PPP is known for the presence of exosomes and other macrovesicles, exerting cell-cell communication and cell signaling. Newly developed ultrafiltration technologies incorporate PPP processing methods by eliminating, in a fast and efficient manner, plasma water, cytokines, molecules, and plasma proteins with a molecular mass (weight) less than the pore size of the fibers. Consequently, a viable and viscous protein concentrate of functional total proteins, like fibrinogen, albumin, and alpha-2-macroglobulin is created. Consolidating a small volume of high platelet concentrate with a small volume of highly concentrated protein-rich PPP creates a protein-rich, platelet-rich plasma (PR-PRP) biological preparation. After the activation of proteins, mainly fibrinogen, the PR-PRP matrix retains and facilitates interactions between invading resident cells, like macrophages, fibroblast, and mesenchymal stem cells (MSCs), as well as the embedded concentrated PRP cells and molecules. The administered PR-PRP biologic will ultimately undergo fibrinolysis, leading to a sustained release of concentrated cells and molecules that have been retained in the PR-PRP matrix until the matrix is dissolved. We will discuss the unique biological and tissue reparative and regenerative properties of the PR-PRP matrix.

Methyl Syringate: A Primary Driving Factor in Manuka Honeys Ability to Ameliorate Neutrophil Intracellular ROS Activity and NETosis

BACKGROUND

Neutrophils use both the production of reactive oxygen species (ROS) and a specialized process called NETosis to defend the body from material deemed foreign. While these neutrophil behaviors are critical in preventing infection, a dysregulated response can lead to tissue damage and fibrosis at host-biomaterial interfaces. It was hypothesized that applying the flavonoids found in Manuka honey: chrysin, pinocembrin, and pinobanksin, and the phenolic compound methyl syringate to neutrophils exhibiting pro-inflammatory behavior will reduce ROS activity and prevent NETosis in primary human neutrophils.

METHODS

Using primary human neutrophils isolated from donor (n = 5) peripheral blood, concentrations between 1 nM and 10 µM of each flavonoid, 10 µM and 2 mM of methyl syringate, 0.1% v/v and 10% v/v Manuka honey, and combinations of both 1 nM-10 µM of each flavonoid and 10 µM-2 mM of methyl syringate were assayed for reductions in NETosis using Sytox orange extracellular DNA staining and reduction in intracellular ROS activity via standard dichloro-dihydro-fluorescein diacetate (DCFH-DA) oxidation assay.

RESULTS

Compared to positive control levels, individual flavonoids showed moderate effect sizes. Higher concentrations of flavonoids, especially in combination, stimulated ROS activity by up to 105%. Whole Manuka honey reduced neutrophil extracellular trap (NET) levels by up to 91% but only reduced ROS activity by 36%. However, methyl syringate reduced NET levels by up to 68% and ROS activity by 66%.

CONCLUSIONS

Methyl syringate and whole Manuka honey are potent inhibitors of neutrophil intracellular ROS activity and NET formation. Methyl syringate potentially drives the anti-inflammatory capabilities of Manuka honey demonstrated by previous studies.

Controlled human hookworm infection remodels plasmacytoid dendritic cells and regulatory T cells towards profiles seen in natural infections in endemic areas

Hookworm infection remains a significant public health concern, particularly in low- and middle-income countries, where mass drug administration has not stopped reinfection. Developing a vaccine is crucial to complement current control measures, which necessitates a thorough understanding of host immune responses. By leveraging controlled human infection models and high-dimensional immunophenotyping, here we investigated the immune remodeling following infection with 50 Necator americanus L3 hookworm larvae in four naïve volunteers over two years of follow-up and compared the profiles with naturally infected populations in endemic areas. Increased plasmacytoid dendritic cell frequency and diminished responsiveness to Toll-like receptor 7/8 ligand were observed in both controlled and natural infection settings. Despite the increased CD45RA+ regulatory T cell (Tregs) frequencies in both settings, markers of Tregs function, including inducible T-cell costimulatory (ICOS), tumor necrosis factor receptor 2 (TNFR2), and latency-associated peptide (LAP), as well as in vitro Tregs suppressive capacity were higher in natural infections. Taken together, this study provides unique insights into the immunological trajectories following a first-in-life hookworm infection compared to natural infections.

Single-cell resolution characterization of myeloid-derived cell states with implication in cancer outcome

Tumor-associated myeloid-derived cells (MDCs) significantly impact cancer prognosis and treatment responses due to their remarkable plasticity and tumorigenic behaviors. Here, we integrate single-cell RNA-sequencing data from different cancer types, identifying 29 MDC subpopulations within the tumor microenvironment. Our analysis reveals abnormally expanded MDC subpopulations across various tumors and distinguishes cell states that have often been grouped together, such as TREM2+ and FOLR2+ subpopulations. Using deconvolution approaches, we identify five subpopulations as independent prognostic markers, including states co-expressing TREM2 and PD-1, and FOLR2 and PDL-2. Additionally, TREM2 alone does not reliably predict cancer prognosis, as other TREM2+ macrophages show varied associations with prognosis depending on local cues. Validation in independent cohorts confirms that FOLR2-expressing macrophages correlate with poor clinical outcomes in ovarian and triple-negative breast cancers. This comprehensive MDC atlas offers valuable insights and a foundation for futher analyses, advancing strategies for treating solid cancers.

Advance on Chinese Medicine for Hypertensive Renal Damage: Focus on the Complex Molecular Mechanisms

Hypertensive renal damage (HRD) is a major cause of end-stage renal disease. Among the causes of end-stage renal disease, HRD accounts for nearly 34% of the total number of cases. Antihypertensive treatment is primarily drug-based, but therapeutic efficacy is less effective and can have serious side effects. Chinese medicine (CM) has significant advantages in the treatment of HRD. CM is rich in various active ingredients and has the property of targeting multiple targets and channels. Therefore, the regulatory network of CM on disease is complex. A large number of CM have been employed to treat HRD, either as single applications or as part of compound formulations. The key possible mechanisms of CM for HRD include regulation of the renin-angiotensin-aldosterone system, antioxidation, anti-inflammation, rescue of endothelial function, regulation of vasoactive substance secretion and obesity-related factors, etc. This review summarized and discussed the recent advance in the basic research mechanisms of CM interventions for HRD and pointed out the challenges and future prospects.

From Genesis to Old Age: Exploring the Immune System One Cell at a Time with Flow Cytometry

The immune system is a highly complex and tightly regulated system that plays a crucial role in protecting the body against external threats, such as pathogens, and internal abnormalities, like cancer cells. It undergoes development during fetal stages and continuously learns from each encounter with pathogens, allowing it to develop immunological memory and provide a wide range of immune protection. Over time, after numerous encounters and years of functioning, the immune system can begin to show signs of erosion, which is commonly named immunosenescence. In this review, we aim to explore how the immune system responds to initial encounters with antigens and how it handles persistent stimulations throughout a person's lifetime. Our understanding of the immune system has greatly benefited from advanced technologies like flow cytometry. In this context, we will discuss the valuable contribution of flow cytometry in enhancing our knowledge of the immune system behavior in aging, with a specific focus on T-cells. Moreover, we will expand our discussion to the flow cytometry-based assessment of extracellular vesicles, a recently discovered communication channel in biology, and their implications for immune system functioning.

The multifaceted functions of DNA-PKcs: implications for the therapy of human diseases

The DNA-dependent protein kinase (DNA-PK), catalytic subunit, also known as DNA-PKcs, is complexed with the heterodimer Ku70/Ku80 to form DNA-PK holoenzyme, which is well recognized as initiator in the nonhomologous end joining (NHEJ) repair after double strand break (DSB). During NHEJ, DNA-PKcs is essential for both DNA end processing and end joining. Besides its classical function in DSB repair, DNA-PKcs also shows multifaceted functions in various biological activities such as class switch recombination (CSR) and variable (V) diversity (D) joining (J) recombination in B/T lymphocytes development, innate immunity through cGAS-STING pathway, transcription, alternative splicing, and so on, which are dependent on its function in NHEJ or not. Moreover, DNA-PKcs deficiency has been proven to be related with human diseases such as neurological pathogenesis, cancer, immunological disorder, and so on through different mechanisms. Therefore, it is imperative to summarize the latest findings about DNA-PKcs and diseases for better targeting DNA-PKcs, which have shown efficacy in cancer treatment in preclinical models. Here, we discuss the multifaceted roles of DNA-PKcs in human diseases, meanwhile, we discuss the progresses of DNA-PKcs inhibitors and their potential in clinical trials. The most updated review about DNA-PKcs will hopefully provide insights and ideas to understand DNA-PKcs associated diseases.

Not an immune cell, but they may act like one-cells with immune properties outside the immune system

The cells presented in this work are not classified as cells that make up the immune system. They, however, present functions and molecules, which are characteristic of immune cells. These characteristic functions are, for example, sensing threat, performing phagocytosis, presentation of foreign antigens, cytokine release or enhancing immune memory. The enlisted immune response mechanisms are carried out by the possession of molecules such as Toll-like receptors, receptors for the Fc fragment of IgG, major histocompatibility complex class II molecules, costimulatory CD80/CD86 proteins and molecules needed for NLRP3 (NOD-like family pyrin domain containing 3) inflammasome activation. Thanks to these properties, the described nonimmune cells play an important role in the local immune response and support of the entire body in the fight against pathogens. They constitute the first line of defense of tissues and organs against pathogens and molecules recognized as harmful. The cells described in this article are particularly important in immunologically privileged places (e.g. the Bowman's capsule in the kidney), where "typical" immune cells normally do not have access. In this paper, we present immune-like functions and molecule suites of resident kidney cells (podocytes and mesangial cells), cochlear resident cells, fibrocytes and fibroblasts, as well as some stem cells (mesenchymal stem cells and umbilical cord Wharton's jelly-derived cells).

The dynamic molecular characteristics of neutrophils are associated with disease progression in dengue patients

Dengue, the most prevalent mosquito-borne disease worldwide, poses a significant health burden. This study integrates clinical data and transcriptomic datasets from different phases of dengue to investigate distinctive and shared cellular and molecular features. Clinical data from 29 dengue patients were collected and analyzed alongside a public transcriptomic data set (GSE28405) to perform differential gene expression analysis, functional enrichment, immune landscape assessment, and development of machine learning model. Neutropenia was observed in 54.79% of dengue patients, particularly during the defervescence phase (65.79%) in clinical cohorts. Bioinformatics analyses corroborated a significant reduction in neutrophil immune infiltration in dengue patients. Receiver operating characteristic curve analysis demonstrated that dynamic changes in neutrophil infiltration levels could predict disease progression, especially during the defervescence phase, with the area under the curve of 0.96. Three neutrophil-associated biomarkers-DHRS12, Transforming growth factor alpha, and ZDHHC19-were identified as promising for diagnosing and predicting dengue progression. In addition, the activation of neutrophil extracellular traps was significantly enhanced and linked to FcγR-mediated signaling pathways and Toll-like receptor signaling pathways. Neutrophil activation and depletion play a critical role in dengue's immune response. The identified biomarkers and their associated pathways offer potential for improved diagnosis and understanding of dengue pathogenesis and progression.

The amoeboid migration of monocytes in confining channels requires the local remodeling of the cortical actin cytoskeleton by cofilin-1

Within the bloodstream, monocytes must traverse the microvasculature to prevent leukostasis, which is the entrapment of monocytes within the confines of the microvasculature. Using the model cell line, THP-1, and VCAM-1 coated channels to simulate the microvasculature surface, we demonstrate that monocytes predominantly adopt an amoeboid phenotype, which is characterized by the formation of blebs. As opposed to cortical actin flow in leader blebs, cell movement is correlated with myosin contraction at the cell rear. It was previously documented that cofilin-1 promotes cortical actin turnover at leader bleb necks in melanoma cells. In monocytes, our data suggest that cofilin-1 promotes the local upregulation of myosin contractility through actin cytoskeleton remodeling. In support of this concept, cofilin-1 is found to localize to a single cell edge. Moreover, the widespread upregulation of myosin contractility was found to inhibit migration. Thus, monocytes within the microvasculature may avoid entrapment by adopting an amoeboid mode of migration.

Vedolizumab Efficacy Is Associated With Decreased Intracolonic Dendritic Cells, Not Memory T Cells

BACKGROUND

Vedolizumab, an antibody blocking integrin α4β7, is a safe and effective therapy for Crohn's disease and ulcerative colitis. Blocking α4β7 from binding its cognate addressin MAdCAM-1 on intestinal blood vessel endothelial cells prevents T cells from migrating to the gut mucosa in animal models. However, data supporting this mechanism of action in humans is limited.

METHODS

We conducted a cross-sectional case-control study to evaluate the effect of vedolizumab on intestinal immune cell populations while avoiding the confounding effect of resolving inflammation on the cellularity of the colonic mucosa in treatment-responsive patients. Colon biopsies from 65 case subjects receiving vedolizumab were matched with biopsies from 65 control individuals, similar in disease type, medications, anatomic location, and inflammation. Biopsies were analyzed by flow cytometry and full messenger RNA transcriptome sequencing of sorted T cells.

RESULTS

No difference was seen between vedolizumab recipients and control individuals in the quantity of any antigen-experienced T lymphocyte subset or in the quality of the transcriptome in any experienced T cell subset. Fewer naïve colonic B and T cells were seen in vedolizumab recipients than control individuals, regardless of response. However, the most striking finding was a marked reduction in CD1c+ (BDCA1+) dendritic cells exclusively in vedolizumab-responsive patients. In blood, these dendritic cells ubiquitously express high levels of α4β7, which is rapidly downregulated upon vedolizumab exposure.

CONCLUSIONS

The clinical effects of vedolizumab reveal integrin α4β7-dependent dendritic cell migration to the intestinal mucosa to be central to inflammatory bowel disease pathogenesis.

Modelling the Impact of NETosis During the Initial Stage of Systemic Lupus Erythematosus

The development of autoimmune diseases often takes years before clinical symptoms become detectable. We propose a mathematical model for the immune response during the initial stage of Systemic Lupus Erythematosus which models the process of aberrant apoptosis and activation of macrophages and neutrophils. NETosis is a type of cell death characterised by the release of neutrophil extracellular traps, or NETs, containing material from the neutrophil's nucleus, in response to a pathogenic stimulus. This process is hypothesised to contribute to the development of autoimmunogenicity in SLE. The aim of this work is to study how NETosis contributes to the establishment of persistent autoantigen production by analysing the steady states and the asymptotic dynamics of the model by numerical experiment.

Interplay of Cytokines and Chemokines in Aspergillosis

Aspergillosis is a fungal infection caused by various species of Aspergillus, most notably A. fumigatus. This fungus causes a spectrum of diseases, including allergic bronchopulmonary aspergillosis, aspergilloma, chronic pulmonary aspergillosis, and invasive aspergillosis. The clinical manifestations and severity of aspergillosis can vary depending on individual immune status and the specific species of Aspergillus involved. The recognition of Aspergillus involves pathogen-associated molecular patterns (PAMPs) such as glucan, galactomannan, mannose, and conidial surface proteins. These are recognized by the pathogen recognition receptors present on immune cells such as Toll-like receptors (TLR-1,2,3,4, etc.) and C-type lectins (Dectin-1 and Dectin-2). We discuss the roles of cytokines and pathogen recognition in aspergillosis from both the perspective of human and experimental infection. Several cytokines and chemokines have been implicated in the immune response to Aspergillus infection, including interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), CCR4, CCR17, and other interleukins. For example, allergic bronchopulmonary aspergillosis (ABPA) is characterized by Th2 and Th9 cell-type immunity and involves interleukin (IL)-4, IL-5, IL-13, and IL-10. In contrast, it has been observed that invasive aspergillosis involves Th1 and Th17 cell-type immunity via IFN-γ, IL-1, IL-6, and IL-17. These cytokines activate various immune cells and stimulate the production of other immune molecules, such as antimicrobial peptides and reactive oxygen species, which aid in the clearance of the fungal pathogen. Moreover, they help to initiate and coordinate the immune response, recruit immune cells to the site of infection, and promote clearance of the fungus. Insight into the host response from both human and animal studies may aid in understanding the immune response in aspergillosis, possibly leading to harnessing the power of cytokines or cytokine (receptor) antagonists and transforming them into precise immunotherapeutic strategies. This could advance personalized medicine.

An analysis of neutrophil-to-lymphocyte ratios and monocyte-to-lymphocyte ratios with six-month prognosis after cerebral contusions

Background and purpose

Neutrophil-to-lymphocyte ratio (NLR) and monocyte-to-lymphocyte ratio (MLR) have been identified as potential prognostic markers in various conditions, including cancer, cardiovascular disease, and stroke. This study aims to investigate the dynamic changes of NLR and MLR following cerebral contusion and their associations with six-month outcomes.

Methods

Retrospective data were collected from January 2016 to April 2020, including patients diagnosed with cerebral contusion and discharged from two teaching-oriented tertiary hospitals in Southern China. Patient demographics, clinical manifestations, laboratory test results (neutrophil, monocyte, and lymphocyte counts) obtained at admission, 24 hours, and one week after cerebral contusion, as well as outcomes, were analyzed. An unfavorable outcome was defined as a Glasgow Outcome Score (GOS) of 0-3 at six months. Logistic regression analysis was performed to identify independent predictors of prognosis, while receiver characteristic curve analysis was used to determine the optimal cutoff values for NLR and MLR.

Results

A total of 552 patients (mean age 47.40, SD 17.09) were included, with 73.19% being male. Higher NLR at one-week post-cerebral contusion (adjusted OR = 4.19, 95%CI, 1.16 - 15.16, P = 0.029) and higher MLR at admission and at 24 h (5.80, 1.40 - 24.02, P = 0.015; 9.06, 1.45 - 56.54, P = 0.018, respectively) were significantly associated with a 6-month unfavorable prognosis after adjustment for other risk factors by multiple logistic regression. The NLR at admission and 24 hours, as well as the MLR at one week, were not significant predictors for a 6-month unfavorable prognosis. Based on receiver operating characteristic curve analysis, the optimal thresholds of NLR at 1 week and MLR at admission after cerebral contusion that best discriminated a unfavorable outcome at 6-month were 6.39 (81.60% sensitivity and 70.73% specificity) and 0.76 (55.47% sensitivity and 78.26% specificity), respectively.

Conclusion

NLR measured one week after cerebral contusion and MLR measured at admission may serve as predictive markers for a 6-month unfavorable prognosis. These ratios hold potential as parameters for risk stratification in patients with cerebral contusion, complementing established biomarkers in diagnosis and treatment. However, further prospective studies with larger cohorts are needed to validate these findings.

Distinct ontogenetic lineages dictate cDC2 heterogeneity

Conventional dendritic cells (cDCs) include functionally and phenotypically diverse populations, such as cDC1s and cDC2s. The latter population has been variously subdivided into Notch-dependent cDC2s, KLF4-dependent cDC2s, T-bet+ cDC2As and T-bet- cDC2Bs, but it is unclear how all these subtypes are interrelated and to what degree they represent cell states or cell subsets. All cDCs are derived from bone marrow progenitors called pre-cDCs, which circulate through the blood to colonize peripheral tissues. Here, we identified distinct mouse pre-cDC2 subsets biased to give rise to cDC2As or cDC2Bs. We showed that a Siglec-H+ pre-cDC2A population in the bone marrow preferentially gave rise to Siglec-H- CD8α+ pre-cDC2As in tissues, which differentiated into T-bet+ cDC2As. In contrast, a Siglec-H- fraction of pre-cDCs in the bone marrow and periphery mostly generated T-bet- cDC2Bs, a lineage marked by the expression of LysM. Our results showed that cDC2A versus cDC2B fate specification starts in the bone marrow and suggest that cDC2 subsets are ontogenetically determined lineages, rather than cell states imposed by the peripheral tissue environment.

Environmental and Health Impacts of Graphene and Other Two-Dimensional Materials: A Graphene Flagship Perspective

Two-dimensional (2D) materials have attracted tremendous interest ever since the isolation of atomically thin sheets of graphene in 2004 due to the specific and versatile properties of these materials. However, the increasing production and use of 2D materials necessitate a thorough evaluation of the potential impact on human health and the environment. Furthermore, harmonized test protocols are needed with which to assess the safety of 2D materials. The Graphene Flagship project (2013-2023), funded by the European Commission, addressed the identification of the possible hazard of graphene-based materials as well as emerging 2D materials including transition metal dichalcogenides, hexagonal boron nitride, and others. Additionally, so-called green chemistry approaches were explored to achieve the goal of a safe and sustainable production and use of this fascinating family of nanomaterials. The present review provides a compact survey of the findings and the lessons learned in the Graphene Flagship.

Single-cell transcriptomics identifies the differentiation trajectory from inflammatory monocytes to pro-resolving macrophages in a mouse skin allergy model

Both monocytes and macrophages are heterogeneous populations. It was traditionally understood that Ly6Chi classical (inflammatory) monocytes differentiate into pro-inflammatory Ly6Chi macrophages. Accumulating evidence has suggested that Ly6Chi classical monocytes can also differentiate into Ly6Clo pro-resolving macrophages under certain conditions, while their differentiation trajectory remains to be fully elucidated. The present study with scRNA-seq and flow cytometric analyses reveals that Ly6ChiPD-L2lo classical monocytes recruited to the allergic skin lesion sequentially differentiate into Ly6CloPD-L2hi pro-resolving macrophages, via intermediate Ly6ChiPD-L2hi macrophages but not Ly6Clo non-classical monocytes, in an IL-4 receptor-dependent manner. Along the differentiation, classical monocyte-derived macrophages display anti-inflammatory signatures followed by metabolic rewiring concordant with their ability to phagocytose apoptotic neutrophils and allergens, therefore contributing to the resolution of inflammation. The failure in the generation of these pro-resolving macrophages drives the IL-1α-mediated cycle of inflammation with abscess-like accumulation of necrotic neutrophils. Thus, we clarify the stepwise differentiation trajectory from Ly6Chi classical monocytes toward Ly6Clo pro-resolving macrophages that restrain neutrophilic aggravation of skin allergic inflammation.

RALDH1 Inhibition Shows Immunotherapeutic Efficacy in Hepatocellular Carcinoma

Globally, hepatocellular carcinoma (HCC) is one of the most commonly diagnosed cancers and a leading cause of cancer-related death. We previously identified an immune evasion pathway whereby tumor cells produce retinoic acid (RA) to promote differentiation of intratumoral monocytes into protumor macrophages. Retinaldehyde dehydrogenase 1 (RALDH1), RALDH2, and RALDH3 are the three isozymes that catalyze RA biosynthesis. In this study, we have identified RALDH1 as the key driver of RA production in HCC and demonstrated the efficacy of RALDH1-selective inhibitors (Raldh1-INH) in suppressing RA production by HCC cells. Raldh1-INH restrained tumor growth in multiple mouse models of HCC by reducing the number and tumor-supporting functions of intratumoral macrophages as well as increasing T-cell infiltration and activation within tumors. Raldh1-INH also displayed favorable pharmacokinetic, pharmacodynamic, and toxicity profiles in mice thereby establishing them as promising new drug candidates for HCC immunotherapy.

Comprehensive view of macrophage autophagy and its application in cardiovascular diseases

Cardiovascular diseases (CVDs) are the primary drivers of the growing public health epidemic and the leading cause of premature mortality and economic burden worldwide. With decades of research, CVDs have been proven to be associated with the dysregulation of the inflammatory response, with macrophages playing imperative roles in influencing the prognosis of CVDs. Autophagy is a conserved pathway that maintains cellular functions. Emerging evidence has revealed an intrinsic connection between autophagy and macrophage functions. This review focuses on the role and underlying mechanisms of autophagy-mediated regulation of macrophage plasticity in polarization, inflammasome activation, cytokine secretion, metabolism, phagocytosis, and the number of macrophages. In addition, autophagy has been shown to connect macrophages and heart cells. It is attributed to specific substrate degradation or signalling pathway activation by autophagy-related proteins. Referring to the latest reports, applications targeting macrophage autophagy have been discussed in CVDs, such as atherosclerosis, myocardial infarction, heart failure, and myocarditis. This review describes a novel approach for future CVD therapies.

The impact of trained immunity in respiratory viral infections

Epidemic peaks of respiratory viruses that co-circulate during the winter-spring seasons can be synchronous or asynchronous. The occurrence of temporal patterns in epidemics caused by some respiratory viruses suggests that they could negatively interact with each other. These negative interactions may result from a programme of innate immune memory, known as trained immunity, which may confer broad protective effects against respiratory viruses. It is suggested that stimulation of innate immune cells by a vaccine or a pathogen could induce their long-term functional reprogramming through an interplay between metabolic and epigenetic changes, which influence the transcriptional response to a secondary challenge. During the coronavirus disease 2019 pandemic, the circulation of most respiratory viruses was prevented by non-pharmacological interventions and then resumed at unusual periods once sanitary measures were lifted. With time, respiratory viruses should find again their own ecological niches. This transition period provides an opportunity to study the interactions between respiratory viruses at the population level.

The Roles of Various Immune Cell Populations in Immune Response against Helminths

Helminths are multicellular parasites that are a substantial problem for both human and veterinary medicine. According to estimates, 1.5 billion people suffer from their infection, resulting in decreased life quality and burdens for healthcare systems. On the other hand, these infections may alleviate autoimmune diseases and allergy symptoms. The immune system is programmed to combat infections; nevertheless, its effector mechanisms may result in immunopathologies and exacerbate clinical symptoms. This review summarizes the role of the immune response against worms, with an emphasis on the Th2 response, which is a hallmark of helminth infections. We characterize non-immune cells (enteric tuft cells-ETCs) responsible for detecting parasites, as well as the role of hematopoietic-derived cells (macrophages, basophils, eosinophils, neutrophils, innate lymphoid cells group 2-ILC2s, mast cells, T cells, and B cells) in initiating and sustaining the immune response, as well as the functions they play in granulomas. The aim of this paper is to review the existing knowledge regarding the immune response against helminths, to attempt to decipher the interactions between cells engaged in the response, and to indicate the gaps in the current knowledge.

Breaking the Silence: Regulation of HIV Transcription and Latency on the Road to a Cure

Antiretroviral therapy (ART) has brought the HIV/AIDS epidemic under control, but a curative strategy for viral eradication is still needed. The cessation of ART results in rapid viral rebound from latently infected CD4+ T cells, showing that control of viral replication alone does not fully restore immune function, nor does it eradicate viral reservoirs. With a better understanding of factors and mechanisms that promote viral latency, current approaches are primarily focused on the permanent silencing of latently infected cells ("block and lock") or reactivating HIV-1 gene expression in latently infected cells, in combination with immune restoration strategies to eliminate HIV infected cells from the host ("shock and kill"). In this review, we provide a summary of the current, most promising approaches for HIV-1 cure strategies, including an analysis of both latency-promoting agents (LPA) and latency-reversing agents (LRA) that have shown promise in vitro, ex vivo, and in human clinical trials to reduce the HIV-1 reservoir.

Neutrophil heterogeneity and aging: implications for COVID-19 and wound healing

Neutrophils play a critical role in the immune response to infection and tissue injury. However, recent studies have shown that neutrophils are a heterogeneous population with distinct subtypes that differ in their functional properties. Moreover, aging can alter neutrophil function and exacerbate immune dysregulation. In this review, we discuss the concept of neutrophil heterogeneity and how it may be affected by aging. We then examine the implications of neutrophil heterogeneity and aging for COVID-19 pathogenesis and wound healing. Specifically, we summarize the evidence for neutrophil involvement in COVID-19 and the potential mechanisms underlying neutrophil recruitment and activation in this disease. We also review the literature on the role of neutrophils in the wound healing process and how aging and neutrophil heterogeneity may impact wound healing outcomes. Finally, we discuss the potential for neutrophil-targeted therapies to improve clinical outcomes in COVID-19 and wound healing.

Advancing CAR-based immunotherapies in solid tumors: CAR- macrophages and neutrophils

Macrophages and neutrophils are the main components of the innate immune system and play important roles in promoting angiogenesis, extracellular matrix remodeling, cancer cell proliferation, and metastasis in the tumor microenvironment (TME). They can also be harnessed to mediate cytotoxic tumor killing effects and orchestrate effective anti-tumor immune responses with proper stimulation and modification. Therefore, macrophages and neutrophils have strong potential in cancer immunotherapy. In this review, we briefly outlined the applications of macrophages or neutrophils in adoptive cell therapies, and focused on chimeric antigen receptor (CAR)-engineered macrophages (CAR-Ms) and neutrophils (CAR-Ns). We summarized the construction strategies, the preclinical and clinical studies of CAR-Ms and CAR-Ns. In the end, we briefly discussed the limitations and challenges of CAR-Ms and CAR-Ns, as well as future research directions to extend their applications in treating solid tumors.

Loss of function of ENT3 drives histiocytosis and inflammation through TLR-MAPK signaling

Histiocytoses are inflammatory myeloid neoplasms often driven by somatic activating mutations in mitogen-activated protein kinase (MAPK) cascade genes. H syndrome is an inflammatory genetic disorder caused by germ line loss-of-function mutations in SLC29A3, encoding the lysosomal equilibrative nucleoside transporter 3 (ENT3). Patients with H syndrome are predisposed to develop histiocytosis, yet the mechanism is unclear. Here, through phenotypic, molecular, and functional analysis of primary cells from a cohort of patients with H syndrome, we reveal the molecular pathway leading to histiocytosis and inflammation in this genetic disorder. We show that loss of function of ENT3 activates nucleoside-sensing toll-like receptors (TLR) and downstream MAPK signaling, inducing cytokine secretion and inflammation. Importantly, MEK inhibitor therapy led to resolution of histiocytosis and inflammation in a patient with H syndrome. These results demonstrate a yet-unrecognized link between a defect in a lysosomal transporter and pathological activation of MAPK signaling, establishing a novel pathway leading to histiocytosis and inflammation.

Understanding cervical cancer at single-cell resolution

Cervical cancer is now the fourth most prevalent malignancy in women worldwide, representing a tremendous burden of cancer. The heterogeneity of complex tumor ecosystem impacts tumorigenesis, malignant progression, and response to treatment; thus, a thorough understanding of the tumor ecosystem is vital for enhancing the prognosis of patients with cervical cancer. The rapid development and widespread use of single-cell sequencing have generated a new paradigm of cancer research, providing a comprehensive and in-depth understanding of cancers. In this review, we give an overview of the recent advances made by leveraging single-cell sequencing studies in the dissection of cervical cancer ecosystem heterogeneity. We highlight the evolution of the cervical cancer ecosystem during tumor initiation, progression, and treatment. High-resolution dissection of cervical cancer at the single-cell level has the potential to drive the development of targeted therapies and enable the realization of personalized medicine.

Bifurcation analysis of a tuberculosis progression model for drug target identification

Tuberculosis (TB) is a major cause of morbidity and mortality worldwide. The emergence and rapid spread of drug-resistant M. tuberculosis strains urge us to develop novel treatments. Experimental trials are constrained by laboratory capacity, insufficient funds, low number of laboratory animals and obsolete technology. Systems-level approaches to quantitatively study TB can overcome these limitations. Previously, we proposed a mathematical model describing the key regulatory mechanisms underlying the pathological progression of TB. Here, we systematically explore the effect of parameter variations on disease outcome. We find five bifurcation parameters that steer the clinical outcome of TB: number of bacteria phagocytosed per macrophage, macrophages death, macrophage killing by bacteria, macrophage recruitment, and phagocytosis of bacteria. The corresponding bifurcation diagrams show all-or-nothing dose-response curves with parameter regions mapping onto bacterial clearance, persistent infection, or history-dependent clearance or infection. Importantly, the pathogenic stage strongly affects the sensitivity of the host to these parameter variations. We identify parameter values corresponding to a latent-infection model of TB, where disease progression occurs significantly slower than in progressive TB. Two-dimensional bifurcation analyses uncovered synergistic parameter pairs that could act as efficient compound therapeutic approaches. Through bifurcation analysis, we reveal how modulation of specific regulatory mechanisms could steer the clinical outcome of TB.