Fractalkine/CX3CL1: a potential new target for inflammatory diseases

In Vivo Release of Zafirlukast from Electrospun Polyisobutylene-Based Fiber Mats to Reduce Capsular Contracture of Silicone Breast Prostheses

Silicone rubber tissue expanders and breast implants are associated with chronic inflammation, leading to the formation of fibrous capsules. If the inflammation is left untreated, the fibrous capsules can become hard and brittle and lead to formation of capsular contracture. When capsular contracture occurs, implant failure and reoperation is unavoidable. Fibrous capsule formation to medical grade silicone rubber breast implants and polyisobutylene-based electrospun fiber mats attached to silicone rubber with and without an anti-inflammatory therapeutic were compared. A linear polyisobutylene (PIB)-based thermoplastic elastomer is currently applied as a polymer coating for drug release on coronary stents to reduce restenosis. Recent work has created a drug releasing electrospun fiber mat from PIB-based materials. Important to this study, poly(alloocimene-b-isobutylene-b-alloocimene) (AIBA) was electrospun with zafirlukast (ZAF). ZAF is an anti-inflammatory drug that is able to reduce capsule formation and complications to silicone breast implants. Fiber mats are advantageous for local drug delivery because of their high porosity and surface area for drug release. The chief hypothesis was that local release of ZAF from AIBA would lower inflammatory signaling and resulting capsular formation after 90 days in vivo. Electrospun AIBA mats locally released ZAF, lowering inflammation and fibrous capsule development compared to medical grade silicone rubber. Locally and orally released ZAF led to similar results, but the former had much lower concentration that highlights local delivery's therapeutic potential. Released ZAF from AIBA fiber mats mitigated inflammation and serves as an alternative to existing clinical approaches.

Neutralization of CX3CL1 Attenuates TGF-β-Induced Fibroblast Differentiation Through NF-κB Activation and Mitochondrial Dysfunction in Airway Fibrosis

BACKGROUND

Severe asthma, characterized by inflammation and airway remodeling, involves fibroblast differentiation into myofibroblasts expressing α-SMA. This process leads to the production of fibronectin and connective tissue growth factor (CTGF), driven by factors such as transforming growth factor (TGF)-β. Furthermore, the persistent presence of myofibroblasts is associated with resistance to apoptosis and mitochondrial dysfunction. The chemokine (C-X3-C motif) ligand 1 (CX3CL1) plays a role in tissue fibrosis. However, it is currently unknown whether neutralization of CX3CL1 decreases TGF-β-induced fibroblast differentiation and mitochondrial dysfunction in normal human lung fibroblasts (NHLFs).

METHODS

CX3CL1/C-X3-C motif chemokine receptor 1 (CX3CR1), CX3CL1 was analyzed by immunofluorescence (IF) or immunohistochemical (IHC) staining of ovalbumin-challenged mice. CX3CL1 release was detected by ELISA. TGF-β-induced CTGF, fibronectin, and α-SMA expression were evaluated in NHLFs following neutralization of CX3CL1 (TP213) treatment for the indicated times by Western blotting or IF staining. Mitochondrion function was detected by a JC-1 assay and seahorse assay. Cell apoptosis was observed by a terminal uridine nick-end labeling (TUNEL) assay.

RESULTS

An increase in CX3CL1 expression was observed in lung tissues from mice with ovalbumin-induced asthma by IF staining. CX3CR1 was increased in the subepithelial layer of the airway by IHC staining. Moreover, CX3CR1 small interfering (si)RNA downregulated TGF-β-induced CTGF and fibronectin expression in NHLFs. CX3CL1 induced CTGF and fibronectin expression in NHLFs. TGF-β-induced CX3CL1 secretion from NHLFs. Furthermore, TP213 decreased TGF-β-induced CTGF, fibronectin, and α-SMA expression in NHLFs. Mitochondrion-related differentially expressed genes (DEGs) were examined after CX3CL1 neutralization in TGF-β-treated NHLFs. TP213 alleviated TGF-β-induced mitochondrial dysfunction and apoptosis resistance in NHLFs. CX3CL1 induced p65, IκBα, and IKKα phosphorylation in a time-dependent manner. Furthermore, CX3CL1-induced fibronectin expression and JC-1 monomer were decreased by p65 siRNA. TP213 reduced TGF-β-induced p65 and α-SMA expression in NHLFs.

CONCLUSIONS

These findings suggest that neutralizing CX3CL1 attenuates lung fibroblast activation and mitochondrial dysfunction. Understanding the impacts of CX3CL1 neutralization on fibroblast mitochondrial function could contribute to the development of therapeutic strategies for managing airway remodeling in severe asthma.

Mild Hypoxia Accelerates Cerebral Cavernous Malformation Disease Through CX3CR1-CX3CL1 Signaling

BACKGROUND

Heterogeneity in the severity of cerebral cavernous malformations (CCMs) disease, including brain bleedings and thrombosis that cause neurological disabilities in patients, suggests that environmental, genetic, or biological factors act as disease modifiers. Still, the underlying mechanisms are not entirely understood. Here, we report that mild hypoxia accelerates CCM disease by promoting angiogenesis, neuroinflammation, and vascular thrombosis in the brains of CCM mouse models.

METHODS

We used genetic studies, RNA sequencing, spatial transcriptome, micro-computed tomography, fluorescence-activated cell sorting, multiplex immunofluorescence, coculture studies, and imaging techniques to reveal that sustained mild hypoxia via the CX3CR1-CX3CL1 (CX3C motif chemokine receptor 1/chemokine [CX3C motif] ligand 1) signaling pathway influences cell-specific neuroinflammatory interactions, contributing to heterogeneity in CCM severity.

RESULTS

Histological and expression profiles of CCM neurovascular lesions (Slco1c1-iCreERT2;Pdcd10fl/fl; Pdcd10BECKO) in male and female mice found that sustained mild hypoxia (12% O2, 7 days) accelerates CCM disease. Our findings indicate that a small reduction in oxygen levels can significantly increase angiogenesis, neuroinflammation, and thrombosis in CCM disease by enhancing the interactions between endothelium, astrocytes, and immune cells. Our study indicates that the interactions between CX3CR1 and CX3CL1 are crucial in the maturation of CCM lesions and propensity to CCM immunothrombosis. In particular, this pathway regulates the recruitment and activation of microglia and other immune cells in CCM lesions, which leads to lesion growth and thrombosis. We found that human CX3CR1 variants are linked to lower lesion burden in familial CCMs, proving it is a genetic modifier in human disease and a potential marker for aggressiveness. Moreover, monoclonal blocking antibody against CX3CL1 or reducing 1 copy of the Cx3cr1 gene significantly reduces hypoxia-induced CCM immunothrombosis.

CONCLUSIONS

Our study reveals that interactions between CX3CR1 and CX3CL1 can modify CCM neuropathology when lesions are accelerated by environmental hypoxia. Moreover, a hypoxic environment or hypoxia signaling caused by CCM disease influences the balance between neuroinflammation and neuroprotection mediated by CX3CR1-CX3CL1 signaling. These results establish CX3CR1 as a genetic marker for patient stratification and a potential predictor of CCM aggressiveness.

Microglia in Ischemic Stroke: Pathogenesis Insights and Therapeutic Challenges

Ischemic stroke is the most common type of stroke, which is the main cause of death and disability on a global scale. As the primary immune cells in the brain that are crucial for preserving homeostasis of the central nervous system microenvironment, microglia have been found to exhibit dual or even multiple effects at different stages of ischemic stroke. The anti-inflammatory polarization of microglia and release of neurotrophic factors may provide benefits by promoting neurological recovery at the lesion in the early phase after ischemic stroke. However, the pro-inflammatory polarization of microglia and secretion of inflammatory factors in the later phase of injury may exacerbate the ischemic lesion, suggesting the therapeutic potential of modulating the balance of microglial polarization to predispose them to anti-inflammatory transformation in ischemic stroke. Microglia-mediated signaling crosstalk with other cells may also be key to improving functional outcomes following ischemic stroke. Thus, this review provides an overview of microglial functions and responses under physiological and ischemic stroke conditions, including microglial activation, polarization, and interactions with other cells. We focus on approaches that promote anti-inflammatory polarization of microglia, inhibit microglial activation, and enhance beneficial cell-to-cell interactions. These targets may hold promise for the creation of innovative therapeutic strategies.

Regulation of iron metabolism in HEC-1A endometrium cells by macrophage-derived factors and fractalkine

Macrophages in the endometrium promote receptivity and implantation by secreting proinflammatory cytokines and other factors like fractalkine (FKN). Macrophages are closely linked to regulating iron homeostasis and can modulate iron availability in the tissue microenvironment. It has been revealed that the iron metabolism of the mother is crucial in fertility. Iron metabolism is strictly controlled by hepcidin, the principal iron regulatory protein. The inflammatory cytokines can modulate hepcidin synthesis and, therefore, the iron metabolism of the endometrium. It was proven recently that FKN, a unique chemokine, is implicated in maternal-fetal communication and may contribute to endometrial receptivity and implantation. In the present study, we investigated the effect of activated THP-1 macrophages and FKN on the iron metabolism of the HEC-1A endometrial cells. We established a noncontact coculture with or without recombinant human FKN supplementation to study the impact of the macrophage-derived factors and FKN on the regulation of hepcidin synthesis and iron release and storage of endometrial cells. Based on our findings, the conditioned medium of the activated macrophages could modify hepcidin synthesis via the nuclear factor kappa-light-chain-enhancer of activated B cells, the signal transducer and activator of transcription 3, and the transferrin receptor 2/bone morphogenetic protein 6/suppressor of mothers against decapentaplegic 1/5/8 signaling pathways, and FKN could alter this effect on the endometrial cells. It was also revealed that the conditioned macrophage medium and FKN modulated the iron release and storage of HEC-1A cells. FKN signaling may be involved in the management of iron trafficking of the endometrium by the regulation of hepcidin. It can contribute to the iron supply for fetal development at the early stage of the pregnancy.

Immune System Dysregulation in the Progression of Multiple Sclerosis: Molecular Insights and Therapeutic Implications

Multiple sclerosis (MS), a prevalent neurological disorder, predominantly affects young adults and is characterized by chronic autoimmune activity. The study explores the immune system dysregulation in MS, highlighting the crucial roles of immune and non-neuronal cells in the disease's progression. This review examines the dual role of cytokines, with some like IL-6, TNF-α, and interferon-gamma (IFN-γ) promoting inflammation and CNS tissue injury, and others such as IL-4, IL-10, IL-37, and TGF-β fostering remyelination and protecting against MS. Elevated chemokine levels in the cerebrospinal fluid (CSF), including CCL2, CCL5, CXCL10, CXCL13, and fractalkine, are analyzed for their role in facilitating immune cell migration across the blood-brain barrier (BBB), worsening inflammation and neurodegeneration. The study also delves into the impact of auto-antibodies targeting myelin components like MOG and AQP4, which activate complement cascades leading to further myelin destruction. The article discusses how compromised BBB integrity allows immune cells and inflammatory mediators to infiltrate the CNS, intensifying MS symptoms. It also examines the involvement of astrocytes, microglia, and oligodendrocytes in the disease's progression. Additionally, the effectiveness of immunomodulatory drugs such as IFN-β and CD20-targeting monoclonal antibodies (e.g., rituximab) in modulating immune responses is reviewed, highlighting their potential to reduce relapse rates and delaying MS progression. These insights emphasize the importance of immune system dysfunction in MS development and progression, guiding the development of new therapeutic strategies. The study underscores recent advancements in understanding MS's molecular pathways, opening avenues for more targeted and effective treatments.

CX3CL1 (Fractalkine)-CX3CR1 Axis in Inflammation-Induced Angiogenesis and Tumorigenesis

The chemotactic cytokine fractalkine (FKN, chemokine CX3CL1) has unique properties resulting from the combination of chemoattractants and adhesion molecules. The soluble form (sFKN) has chemotactic properties and strongly attracts T cells and monocytes. The membrane-bound form (mFKN) facilitates diapedesis and is responsible for cell-to-cell adhesion, especially by promoting the strong adhesion of leukocytes (monocytes) to activated endothelial cells with the subsequent formation of an extracellular matrix and angiogenesis. FKN signaling occurs via CX3CR1, which is the only known member of the CX3C chemokine receptor subfamily. Signaling within the FKN-CX3CR1 axis plays an important role in many processes related to inflammation and the immune response, which often occur simultaneously and overlap. FKN is strongly upregulated by hypoxia and/or inflammation-induced inflammatory cytokine release, and it may act locally as a key angiogenic factor in the highly hypoxic tumor microenvironment. The importance of the FKN/CX3CR1 signaling pathway in tumorigenesis and cancer metastasis results from its influence on cell adhesion, apoptosis, and cell migration. This review presents the role of the FKN signaling pathway in the context of angiogenesis in inflammation and cancer. The mechanisms determining the pro- or anti-tumor effects are presented, which are the cause of the seemingly contradictory results that create confusion regarding the therapeutic goals.

Alterations in CX3CL1 Levels and Its Role in Viral Pathogenesis

CX3CL1, also named fractalkine or neurotactin, is the only known member of the CX3C chemokine family that can chemoattract several immune cells. CX3CL1 exists in both membrane-anchored and soluble forms, with each mediating distinct biological activities. CX3CL1 signals are transmitted through its unique receptor, CX3CR1, primarily expressed in the microglia of the central nervous system (CNS). In the CNS, CX3CL1 acts as a regulator of microglia activation in response to brain disorders or inflammation. Recently, there has been a growing interest in the role of CX3CL1 in regulating cell adhesion, chemotaxis, and host immune response in viral infection. Here, we provide a comprehensive review of the changes and function of CX3CL1 in various viral infections, such as human immunodeficiency virus (HIV), SARS-CoV-2, influenza virus, and cytomegalovirus (CMV) infection, to highlight the emerging roles of CX3CL1 in viral infection and associated diseases.

Unraveling the enigma: housekeeping gene Ugt1a7c as a universal biomarker for microglia

Background

Microglia, brain resident macrophages, play multiple roles in maintaining homeostasis, including immunity, surveillance, and protecting the central nervous system through their distinct activation processes. Identifying all types of microglia-driven populations is crucial due to the presence of various phenotypes that differ based on developmental stages or activation states. During embryonic development, the E8.5 yolk sac contains erythromyeloid progenitors that go through different growth phases, eventually resulting in the formation of microglia. In addition, microglia are present in neurological diseases as a diverse population. So far, no individual biomarker for microglia has been discovered that can accurately identify and monitor their development and attributes.

Summary

Here, we highlight the newly defined biomarker of mouse microglia, UGT1A7C, which exhibits superior stability in expression during microglia development and activation compared to other known microglia biomarkers. The UGT1A7C sensing chemical probe labels all microglia in the 3xTG AD mouse model. The expression of Ugt1a7c is stable during development, with only a 4-fold variation, while other microglia biomarkers, such as Csf1r and Cx3cr1, exhibit at least a 10-fold difference. The UGT1A7C expression remains constant throughout its lifespan. In addition, the expression and activity of UGT1A7C are the same in response to different types of inflammatory activators' treatment in vitro.

Conclusion

We propose employing UGT1A7C as the representative biomarker for microglia, irrespective of their developmental state, age, or activation status. Using UGT1A7C can reduce the requirement for using multiple biomarkers, enhance the precision of microglia analysis, and even be utilized as a standard for gene/protein expression.

Chemokine Fractalkine and Non-Obstructive Coronary Artery Disease-Is There a Link?

Non-obstructive coronary artery disease (NO-CAD) constitutes a heterogeneous group of conditions collectively characterized by less than 50% narrowing in at least one major coronary artery with a fractional flow reserve (FFR) of ≤0.80 observed in coronary angiography. The pathogenesis and progression of NO-CAD are still not fully understood, however, inflammatory processes, particularly atherosclerosis and microvascular dysfunction are known to play a major role in it. Chemokine fractalkine (FKN/CX3CL1) is inherently linked to these processes. FKN/CX3CL1 functions predominantly as a chemoattractant for immune cells, facilitating their transmigration through the vessel wall and inhibiting their apoptosis. Its concentrations correlate positively with major cardiovascular risk factors. Moreover, promising preliminary results have shown that FKN/CX3CL1 receptor inhibitor (KAND567) administered in the population of patients with ST-elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI), inhibits the adverse reaction of the immune system that causes hyperinflammation. Whereas the link between FKN/CX3CL1 and NO-CAD appears evident, further studies are necessary to unveil this complex relationship. In this review, we critically overview the current data on FKN/CX3CL1 in the context of NO-CAD and present the novel clinical implications of the unique structure and function of FKN/CX3CL1 as a compound which distinctively contributes to the pathomechanism of this condition.

Approaches of marine compounds and relevant immune mediators in Autism Spectrum Disorder: Opportunities and challenges

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that affects social skills, language, communication, and behavioral skills, significantly impacting the individual's quality of life. Recently, numerous works have centered on the connections between the immune and central nervous systems and the influence of neuroinflammation on autism symptomatology. Marine natural products are considered as important alternative sources of different types of compounds, including polysaccharides, polyphenols, sterols, carotenoids, terpenoids and, alkaloids. These compounds present anti-inflammatory, neuroprotective and immunomodulatory activities, exhibiting a potential for the treatment of many diseases. Although many studies address the marine compounds in the modulation of inflammatory mediators, there is a gap regarding their use in the regulation of the immune system in ASD. Thus, this review aims to provide a better understanding regarding cytokines, chemokines, growth factors and immune responses in ASD, as well as the potential of bioactive marine compounds in the immune regulation in ASD. We expect that this review would contribute to the development of therapeutic alternatives for controlling immune mediators and inflammation in ASD.

SQLE is a promising prognostic and immunological biomarker and correlated with immune Infiltration in Sarcoma

Squalene epoxidase (SQLE) is an essential enzyme involved in cholesterol biosynthesis. However, its role in sarcoma and its correlation with immune infiltration remains unclear. All original data were downloaded from The Cancer Genome Atlas (TCGA). SQLE expression was explored using the TCGA database, and correlations between SQLE and cancer immune characteristics were analyzed via the TISIDB databases. Generally, SQLE is predominantly overexpressed and has diagnostic and prognostic value in sarcoma. Upregulated SQLE was associated with poorer overall survival, poorer disease-specific survival, and tumor multifocality in sarcoma. Mechanistically, we identified a hub gene that included a total of 82 SQLE-related genes, which were tightly associated with histone modification pathways in sarcoma patients. SQLE expression was negatively correlated with infiltrating levels of dendritic cells and plasmacytoid dendritic cells and positively correlated with Th2 cells. SQLE expression was negatively correlated with the expression of chemokines (CCL19 and CX3CL1) and chemokine receptors (CCR2 and CCR7) in sarcoma. In conclusion, SQLE may be used as a prognostic biomarker for determining prognosis and immune infiltration in sarcoma.

Fractalkine isoforms differentially regulate microglia-mediated inflammation and enhance visual function in the diabetic retina

Diabetic retinopathy (DR) affects about 200 million people worldwide, causing leakage of blood components into retinal tissues, leading to activation of microglia, the resident phagocytes of the retina, promoting neuronal and vascular damage. The microglial receptor, CX3CR1, binds to fractalkine (FKN), an anti-inflammatory chemokine that is expressed on neuronal membranes (mFKN), and undergoes constitutive cleavage to release a soluble domain (sFKN). Deficiencies in CX3CR1 or FKN showed increased microglial activation, inflammation, vascular damage, and neuronal loss in experimental mouse models. To understand the mechanism that regulates microglia function, recombinant adeno-associated viral vectors (rAAV) expressing mFKN or sFKN were delivered to intact retinas prior to diabetes. High-resolution confocal imaging and mRNA-seq were used to analyze microglia morphology and markers of expression, neuronal and vascular health, and inflammatory mediators. We confirmed that prophylactic intra-vitreal administration of rAAV expressing sFKN (rAAV-sFKN), but not mFKN (rAAV-mFKN), in FKNKO retinas provided vasculo- and neuro-protection, reduced microgliosis, mitigated inflammation, improved overall optic nerve health by regulating microglia-mediated inflammation, and prevented fibrin(ogen) leakage at 4 weeks and 10 weeks of diabetes induction. Moreover, administration of sFKN improved visual acuity. Our results elucidated a novel intervention via sFKN gene therapy that provides an alternative pathway to implement translational and therapeutic approaches, preventing diabetes-associated blindness.

Gene-expression profiling of laser-dissected islets and studies in deficient mice reveal chemokines as differential driving force of type 1 diabetes

Although type 1 diabetes (T1D) results from the autoimmune destruction of the insulin-producing β-cells, its treatment is largely restricted to exogenous insulin administration. Only few therapies targeting the autoaggressive immune system have been introduced into clinical practice or are considered in clinical trials. Here, we provide a gene expression profile of the islet microenvironment obtained by laser-dissection microscopy in an inducible mouse model. Thereby, we have identified novel targets for immune intervention. Increased gene expression of most inflammatory proteins was apparent at day 10 after T1D induction and largely paralleled the observed degree of insulitis. We further focused on genes involved in leukocyte migration, including chemokines and their receptors. Besides the critical chemokine CXCL10, we found several other chemokines upregulated locally in temporary or chronic manner. Localization of the chemokine ligand/receptor pairs to the islet microenvironment has been confirmed by RNAscope. Interference with the CXCL16-CXCR6 and CX3CL1-CX3CR1 axes, but not the CCL5-CCR1/3/5 axis, resulted in reduced insulitis and lower T1D incidence. Further, we found that the receptors for the differentially expressed chemokines CXCL10, CXCL16 and CX3CL1 are distributed unevenly among islet autoantigen-specific T cells, which explains why the interference with just one chemokine axis cannot completely abrogate insulitis and T1D.

Validating Fractalkine receptor as a target and identifying candidates for drug discovery against type 2 diabetes

Type 2 diabetes mellitus (T2DM) is one of the most common chronic diseases employing abnormal levels of insulin. Enhancing the insulin production is greatly aided by the regulatory mechanisms of the Fractalkine receptor (CX3CR1) system in islet β-cell function. However, elements including a high-fat diet, obesity, and ageing negatively impact the expression of CX3CR1 in islets. CX3CL1/CX3CR1 receptor-ligand complex is now recognized as a novel therapeutic target. It suggests that T2DM-related β-cell dysfunction may result from lower amount of these proteins. We analyzed the differential expression of CX3CR1 gene samples taken from persons with T2DM using data obtained from the Gene Expression Omnibus database. Homology modeling enabled us to generate the three-dimensional structure of CX3CR1 and a possible binding pocket. The optimized CX3CR1 structure was subjected to rigorous screening against a massive library of 693 million drug-like molecules from the ZINC15 database. This screening process led to the identification of three compounds with strong binding affinity at the identified binding pocket of CX3CR1. To further evaluate the potential of these compounds, molecular dynamics simulations were conducted over a 50 ns time scale to assess the stability of the protein-ligand complexes. These simulations revealed that ZINC000032506419 emerged as the most promising drug-like compound among the three potent molecules. The discovery of ZINC000032506419 holds exciting promise as a potential therapeutic agent for T2D and other related metabolic disorders. These findings pave the way for the development of effective medications to address the complexities of T2DM and its associated metabolic diseases.

The cytokine trio - visfatin, placental growth factor and fractalkine - and their role in myocardial infarction with non-obstructive coronary arteries (MINOCA)

Myocardial infarction with nonobstructive coronary arteries (MINOCA) remains a puzzling clinical entity. It is characterized by clinical evidence of myocardial infarction (MI) with normal or near-normal coronary arteries in angiography. Given the complex etiology including multiple possible scenarios with varied pathogenetic mechanisms, profound investigation of the plausible biomarkers of MINOCA may bring further pathophysiological insights and novel diagnostic opportunities. Cytokines have a great diagnostic potential and are used as biomarkers for many diseases. An unusual trio of visfatin, placental growth factor (PlGF) and fractalkine (CX3CL1) can directly promote vascular dysfunction, inflammation and angiogenesis through the activation of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling. They are redundant in physiological processes and become overexpressed in the pathomechanisms underlying MINOCA. The knowledge about their concentration might serve as a valuable diagnostic and/or therapeutic tool for assessing vascular endothelial function. Here we analyze the current knowledge on visfatin, PlGF and CX3CL1 in the context of MINOCA and present the novel clinical implications of their combined expression as predictors or indicators of this condition.

Host Responses to Respiratory Syncytial Virus Infection

Respiratory syncytial virus (RSV) infections are a constant public health problem, especially in infants and older adults. Virtually all children will have been infected with RSV by the age of two, and reinfections are common throughout life. Since antigenic variation, which is frequently observed among other respiratory viruses such as SARS-CoV-2 or influenza viruses, can only be observed for RSV to a limited extent, reinfections may result from short-term or incomplete immunity. After decades of research, two RSV vaccines were approved to prevent lower respiratory tract infections in older adults. Recently, the FDA approved a vaccine for active vaccination of pregnant women to prevent severe RSV disease in infants during their first RSV season. This review focuses on the host response to RSV infections mediated by epithelial cells as the first physical barrier, followed by responses of the innate and adaptive immune systems. We address possible RSV-mediated immunomodulatory and pathogenic mechanisms during infections and discuss the current vaccine candidates and alternative treatment options.

Age-dependent changes on fractalkine forms and their contribution to neurodegenerative diseases

The chemokine fractalkine (FKN, CX3CL1), a member of the CX3C subfamily, contributes to neuron-glia interaction and the regulation of microglial cell activation. Fractalkine is expressed by neurons as a membrane-bound protein (mCX3CL1) that can be cleaved by extracellular proteases generating several sCX3CL1 forms. sCX3CL1, containing the chemokine domain, and mCX3CL1 have high affinity by their unique receptor (CX3CR1) which, physiologically, is only found in microglia, a resident immune cell of the CNS. The activation of CX3CR1contributes to survival and maturation of the neural network during development, glutamatergic synaptic transmission, synaptic plasticity, cognition, neuropathic pain, and inflammatory regulation in the adult brain. Indeed, the various CX3CL1 forms appear in some cases to serve an anti-inflammatory role of microglia, whereas in others, they have a pro-inflammatory role, aggravating neurological disorders. In the last decade, evidence points to the fact that sCX3CL1 and mCX3CL1 exhibit selective and differential effects on their targets. Thus, the balance in their level and activity will impact on neuron-microglia interaction. This review is focused on the description of factors determining the emergence of distinct fractalkine forms, their age-dependent changes, and how they contribute to neuroinflammation and neurodegenerative diseases. Changes in the balance among various fractalkine forms may be one of the mechanisms on which converge aging, chronic CNS inflammation, and neurodegeneration.

The multifaceted role of macrophages during acute liver injury

The liver is situated at the interface of the gut and circulation where it acts as a filter for blood-borne and gut-derived microbes and biological molecules, promoting tolerance of non-invasive antigens while driving immune responses against pathogenic ones. Liver resident immune cells such as Kupffer cells (KCs), a subset of macrophages, maintain homeostasis under physiological conditions. However, upon liver injury, these cells and others recruited from circulation participate in the response to injury and the repair of tissue damage. Such response is thus spatially and temporally regulated and implicates interconnected cells of immune and non-immune nature. This review will describe the hepatic immune environment during acute liver injury and the subsequent wound healing process. In its early stages, the wound healing immune response involves a necroinflammatory process characterized by partial depletion of resident KCs and lymphocytes and a significant infiltration of myeloid cells including monocyte-derived macrophages (MoMFs) complemented by a wave of pro-inflammatory mediators. The subsequent repair stage includes restoring KCs, initiating angiogenesis, renewing extracellular matrix and enhancing proliferation/activation of resident parenchymal and mesenchymal cells. This review will focus on the multifaceted role of hepatic macrophages, including KCs and MoMFs, and their spatial distribution and roles during acute liver injury.

Intake of Lactiplantibacillus plantarum HEAL9 Improves Cognition in Moderately Stressed Subjects: A Randomized Controlled Study

BACKGROUND

The usage of probiotics has expanded beyond the areas of gut and immune health improvement. Several studies have shown the positive impact associated between probiotics and stress, cognition, and mood; a relationship referred to as the gut-brain axis.

METHOD

The aim of this exploratory study was to evaluate the effect of the probiotic strain Lactiplantibacillus plantarum HEAL9 (LPHEAL9) on the gut-brain axis in subjects with moderate stress. One hundred and twenty-nine subjects aged 21-52 years completed the study, randomized to consume either LPHEAL9 (n = 65) or placebo (n = 64) for 12 weeks.

RESULTS

Perceived stress and awakening cortisol were significantly reduced over time in both groups. A significant improvement in four cognition tests after consumption of LPHEAL9 compared to placebo was observed (rapid information processing test, numeric working memory test, paired associated learning, and word recall, p < 0.05). There was a tendency for a significantly better improvement in the LPHEAL9 group for three mood subscales (Confusion-Bewilderment, Anger-Hostility, and Depression-Dejection) and for fewer subjects with poor sleep in the LPHEAL9 group compared to placebo (p < 0.10).

CONCLUSIONS

Intake of LPHEAL9 significantly improved cognitive functions compared to the placebo, potentially by ameliorating aspects of mood and sleep.

Immunological perturbations, psychiatric disorders and associated therapeutics: a new era for psychiatry?

The three main theories explaining major mental illness, namely mood disorders, psychoses and dementias, have been partially discredited. Alongside this, there are emerging links between perturbations of the immune system and the onset and phenotypic features of these disorders. This article outlines the alternative pathophysiology and suggests potential treatments which could improve disease burden and avoid the need for psychotropic medication, with their associated side effects and relapse following withdrawal.

Systemic immune parameters after prior radiation therapy in patients receiving immune checkpoint inhibitors

INTRODUCTION

Preclinical studies have demonstrated the ability of radiation therapy (RT) to augment immune response and tumor control by immune checkpoint inhibitors (ICI). However, numerous clinical trials combining RT and ICI have yielded relatively disappointing results. To improve understanding of optimal use of these therapies, we assessed systemic immune effects of prior RT in patients receiving ICI.

METHODS AND MATERIALS

Pre- and post-ICI blood samples were collected from patients enrolled in a prospective immunotherapy biospecimen protocol. Mutiplex panels of 40 cytokines and 120 autoantibodies (Ab) were analyzed. We identified differences in these parameters according to receipt, timing, and type of prior RT. We calculated P values using the Pearson product-moment correlation coefficient and false discovery rate (FDR) using the Benjamini-Hochberg Procedure.

RESULTS

Among 277 total patients, 69 (25%) received RT in the 6 months prior to ICI initiation. Among RT-treated patients, 23 (33%) received stereotactic RT, and 33 (48%) received curative intent RT. There was no significant difference in demographics or type of immunotherapy between patients according to prior RT exposure. Baseline complement C8 Ab and MIP-1d/CCL15 were significantly higher among patients with prior RT. For MIP-1d/CCL15, only prior stereotactic RT was associated with significant differences.

CONCLUSIONS

Prior RT is associated with few changes in systemic immune parameters in patients receiving ICI. The underlying mechanisms and optimal approach to harnessing the potential synergy of RT and ICI require further prospective clinical investigation.

Fractalkine Signalling (CX3CL1/CX3CR1 Axis) as an Emerging Target in Coronary Artery Disease

Acute myocardial infarction (MI) is the most common and dramatic complication of atherosclerosis, which, despite successful reperfusion therapy, can lead to incident heart failure (HF). HF occurs when the healing process is impaired due to adverse left ventricular remodelling, and can be the result of so-called ischaemia/reperfusion injury (IRI), visualised by the development of intramyocardial haemorrhage (IMH) or microvascular obstruction (MVO) in cardiac MRI. Thus far, translation of novel pharmacological strategies from preclinical studies to target either IRI or HF post MI have been largely unsuccessful. Anti-inflammatory therapies also carry the risk of affecting the immune system. Fractalkine (FKN, CX3CL1) is a unique chemokine, present as a transmembrane protein on the endothelium, or following cleavage as a soluble ligand, attracting leukocyte subsets expressing the corresponding receptor CX3CR1. We have shown previously that the fractalkine receptor CX3CR1 is associated with MVO in patients undergoing primary PCI. Moreover, inhibition of CX3CR1 with an allosteric small molecule antagonist (KAND567) in the rat MI model reduces acute infarct size, inflammation, and IMH. Here we review the cellular biology of fractalkine and its receptor, along with ongoing studies that introduce CX3CR1 as a future target in coronary artery disease, specifically in patients with myocardial infarction.

ACSL1 is a key regulator of inflammatory and macrophage foaming induced by short-term palmitate exposure or acute high-fat feeding

Foamy and inflammatory macrophages play pathogenic roles in metabolic disorders. However, the mechanisms that promote foamy and inflammatory macrophage phenotypes under acute-high-fat feeding (AHFF) remain elusive. Herein, we investigated the role of acyl-CoA synthetase-1 (ACSL1) in favoring the foamy/inflammatory phenotype of monocytes/macrophages upon short-term exposure to palmitate or AHFF. Palmitate exposure induced a foamy/inflammatory phenotype in macrophages which was associated with increased ACSL1 expression. Inhibition/knockdown of ACSL1 in macrophages suppressed the foamy/inflammatory phenotype through the inhibition of the CD36-FABP4-p38-PPARδ signaling axis. ACSL1 inhibition/knockdown suppressed macrophage foaming/inflammation after palmitate stimulation by downregulating the FABP4 expression. Similar results were obtained using primary human monocytes. As expected, oral administration of ACSL1 inhibitor triacsin-C in mice before AHFF normalized the inflammatory/foamy phenotype of the circulatory monocytes by suppressing FABP4 expression. Our results reveal that targeting ACSL1 leads to the attenuation of the CD36-FABP4-p38-PPARδ signaling axis, providing a therapeutic strategy to prevent the AHFF-induced macrophage foaming and inflammation.

Chemo Markers as Biomarkers in Septic Shock: A Comprehensive Review of Their Utility and Clinical Applications

Sepsis is a life-threatening condition characterized by a dysregulated host response to infection, often leading to septic shock. Early diagnosis and prompt intervention are crucial for improving patient outcomes. Chemo markers, which are measurable biological substances associated with the pathophysiology of septic shock, have emerged as potential biomarkers for the identification, risk stratification, and management of this condition. This comprehensive review aims to thoroughly evaluate the utility and clinical applications of chemo markers in septic shock. The review begins by discussing the criteria for ideal chemo markers, including specificity, sensitivity, dynamic range, stability, non-invasiveness, and prognostic value. These characteristics ensure accurate diagnosis, early detection, effective monitoring, and prediction of clinical outcomes. Furthermore, the review explores the role of chemo markers in monitoring treatment response and disease progression, highlighting their ability to serve as objective indicators for assessing the effectiveness of interventions and making timely adjustments in management strategies. Moreover, the prognostic value of chemo markers in predicting outcomes is discussed, emphasizing their association with mortality, hospital stays, and the development of complications. Integration of chemo markers into prognostic models or scoring systems enhances risk stratification and informs therapeutic decisions. The review also delves into recent advances in chemo marker research and technology, emphasizing the potential for discovering novel chemo markers with enhanced diagnostic and prognostic capabilities. It highlights the use of high-throughput proteomics, genomics, and transcriptomics in identifying specific molecular signatures associated with septic shock. This contributes to a deeper understanding of the complex immune and inflammatory responses involved. In conclusion, chemo markers have emerged as valuable biomarkers in septic shock, offering potential utility in diagnosis, risk stratification, treatment monitoring, and prediction of outcomes. Continued research, validation, and integration into clinical practice are necessary to fully realize their potential in improving patient care and outcomes in septic shock.

The Role of Fractalkine in the Regulation of Endometrial Iron Metabolism in Iron Deficiency

Iron is a crucial element in the human body. Endometrial iron metabolism is implicated in endometrium receptivity and embryo implantation. Disturbances of the maternal as well as the endometrial iron homeostasis, such as iron deficiency, can contribute to the reduced development of the fetus and could cause an increased risk of adverse pregnancy outcomes. Fractalkine is a unique chemokine that plays a role in the communication between the mother and the fetus. It has been demonstrated that FKN is involved in the development of endometrial receptivity and embryo implantation, and it functions as a regulator of iron metabolism. In the present study, we examined the effect of FKN on the iron metabolism of HEC-1A endometrial cells in a state of iron deficiency mediated by desferrioxamine treatment. Based on the findings, FKN enhances the expression of iron metabolism-related genes in iron deficiency and modifies the iron uptake via transferrin receptor 1 and divalent metal transporter-1, and iron release via ferroportin. FKN can activate the release of iron from heme-containing proteins by elevating the level of heme oxygenase-1, contributing to the redistribution of intracellular iron content. It was revealed that the endometrium cells express both mitoferrin-1 and 2 and that their levels are not dependent on the iron availability of the cells. FKN may also contribute to maintaining mitochondrial iron homeostasis. FKN can improve the deteriorating effect of iron deficiency in HEC-1A endometrium cells, which may contribute to the development of receptivity and/or provide iron delivery towards the embryo.

The Cytokine CX3CL1 and ADAMs/MMPs in Concerted Cross-Talk Influencing Neurodegenerative Diseases

Neuroinflammation plays a fundamental role in the development and progression of neurodegenerative diseases. It could therefore be said that neuroinflammation in neurodegenerative pathologies is not a consequence but a cause of them and could represent a therapeutic target of neuronal degeneration. CX3CL1 and several proteases (ADAMs/MMPs) are strongly involved in the inflammatory pathways of these neurodegenerative pathologies with multiple effects. On the one hand, ADAMs have neuroprotective and anti-apoptotic effects; on the other hand, they target cytokines and chemokines, thus causing inflammatory processes and, consequently, neurodegeneration. CX3CL1 itself is a cytokine substrate for the ADAM, ADAM17, which cleaves and releases it in a soluble isoform (sCX3CL1). CX3CL1, as an adhesion molecule, on the one hand, plays an inhibiting role in the pro-inflammatory response in the central nervous system (CNS) and shows neuroprotective effects by binding its membrane receptor (CX3CR1) present into microglia cells and maintaining them in a quiescent state; on the other hand, the sCX3CL1 isoform seems to promote neurodegeneration. In this review, the dual roles of CX3CL1 and ADAMs/MMPs in different neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (MH), and multiple sclerosis (MS), are investigated.

Fractalkine Improves the Expression of Endometrium Receptivity-Related Genes and Proteins at Desferrioxamine-Induced Iron Deficiency in HEC-1A Cells

Fractalkine (CX3CL1/FKN) is a unique chemokine belonging to the CX3C chemokine subclass. FKN exists in two forms: a membrane-bound form expressed by both endometrium cells and trophoblasts thought to be implicated in maternal-fetal interaction and a soluble form expressed by endometrium cells. Endometrium receptivity is crucial in embryo implantation and a complex process regulated by large numbers of proteins, e.g., cytokines, progesterone receptor (PR), SOX-17, prostaglandin receptors (PTGER2), and tissue inhibitors of metalloproteinases (TIMPs). It has also been reported that iron is important in fertility and affects the iron status of the mother. Therefore, iron availability in the embryo contributes to fertilization and pregnancy. In this study, we focused on the effect of iron deficiency on the secreted cytokines (IL-6, IL-1β, leukocyte inhibitory factor, TGF-β), chemokines (IL-8, FKN), and other regulatory proteins (bone morphogenic protein 2, activin, follistatin, PR, SOX-17, prostaglandin E2 receptor, TIMP2), and the modifying effect of FKN on the expression of these proteins, which may improve endometrium receptivity. Endometrial iron deficiency was mediated by desferrioxamine (DFO) treatment of HEC-1A cells. FKN was added to the cells 24 h and 48 h after DFO with or without serum for modelling the possible iron dependence of the alterations. Our findings support the hypothesis that FKN ameliorates the effects of anemia on the receptivity-related genes and proteins in HEC-1A cells by increasing the secretion of the receptivity-related cytokines via the fractalkine receptor (CX3CR1). FKN may contribute to cell proliferation and differentiation by regulating activin, follistatin, and BMP2 expressions, and to implantation by altering the protein levels of PR, SOX-17, PTGER2, and TIMP2. FKN mitigates the negative effect of iron deficiency on the receptivity-related genes and proteins of HEC-1A endometrium cells, suggesting its important role in the regulation of endometrium receptivity.

Whole genome sequencing of simmental cattle for SNP and CNV discovery

BACKGROUD

The single nucleotide polymorphisms (SNPs) and copy number variations (CNVs) are two major genomic variants, which play crucial roles in evolutionary and phenotypic diversity.

RESULTS

In this study, we performed a comprehensive analysis to explore the genetic variations (SNPs and CNVs) of high sperm motility (HSM) and poor sperm motility (PSM) Simmental bulls using the high-coverage (25×) short-read next generation sequencing and single-molecule long reads sequencing data. A total of ~ 15 million SNPs and 2,944 CNV regions (CNVRs) were detected in Simmental bulls, and a set of positive selected genes (PSGs) and CNVRs were found to be overlapped with quantitative trait loci (QTLs) involving immunity, muscle development, reproduction, etc. In addition, we detected two new variants in LEPR, which may be related to the artificial breeding to improve important economic traits. Moreover, a set of genes and pathways functionally related to male fertility were identified. Remarkably, a CNV on SPAG16 (chr2:101,427,468 - 101,429,883) was completely deleted in all poor sperm motility (PSM) bulls and half of the bulls in high sperm motility (HSM), which may play a crucial role in the bull-fertility.

CONCLUSIONS

In conclusion, this study provides a valuable genetic variation resource for the cattle breeding and selection programs.

Exhausted CD8+ T cells face a developmental fork in the road

Reinvigorating the function of exhausted CD8+ T cells during chronic viral infection and cancer is a major goal of current immunotherapy regimens. Here, we discuss recent advances in our understanding of exhausted CD8+ T cell heterogeneity as well as the potential differentiation trajectories that exhausted T cells follow during chronic infection and/or cancer. We highlight surmounting evidence suggesting that some T cell clones are divergent in nature and can develop into either terminally differentiated effector or exhausted CD8+ T cells. Lastly, we consider the potential therapeutic implications of such a bifurcation model of CD8+ T cell differentiation, including the intriguing hypothesis that redirecting progenitor CD8+ T cell differentiation along an effector pathway may serve as a novel approach to mitigate T cell exhaustion.

Nicotinic acetylcholine receptors: Key targets for attenuating neurodegenerative diseases

Nicotinic acetylcholine receptors (nAChRs) are master regulators of immune functions via the cholinergic anti-inflammatory pathway and are expressed in microglia, the brain's resident immune cells. There is an extensive dialogue between the neurons and the glial cells around them from which microglia are tasked with monitoring, nurturing, and defending their microenvironment. Dysregulation of any of these processes can have devastating and long-lasting consequences involving microglia-mediated neuroinflammation associated with neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease, amongst others. Disease-associated microglia acquire a distinguishing phenotype that emphasizes scavenging and defence functions while nurturing and repairing functions become muted. Attempts to resolve this critical imbalance remain a key focus of research. Furthermore, cholinergic modulation of neuroinflammation represents a promising avenue for treatment.

Identification and Characterization of TMEM119-Positive Cells in the Postnatal and Adult Murine Cochlea

Transmembrane protein 119 (TMEM119) is expressed in a subset of resident macrophage cells of the brain and was proposed as a marker for native brain microglia. The presence of cells expressing TMEM119 in the cochlea has not yet been described. Thus, the present study aimed to characterize the TMEM119-expressing cells of the postnatal and adult cochlea, the latter also after noise exposure. Immunofluorescent staining of cochlear cryosections detected TMEM119 protein in the spiral limbus fibrocytes and the developing stria vascularis at postnatal Day 3. Applying the macrophage marker Iba1 revealed that TMEM119 is not a marker of cochlear macrophages or a subset of them. In the adult murine cochlea, TMEM119 expression was detected in the basal cells of the stria vascularis and the dark mesenchymal cells of the supralimbal zone. Exposure to noise trauma was not associated with a qualitative change in the types or distributions of the TMEM119-expressing cells of the adult cochlea. Western blot analysis indicated a similar TMEM119 protein expression level in the postnatal cochlea and brain tissues. The findings do not support using TMEM119 as a specific microglial or macrophage marker in the cochlea. The precise role of TMEM119 in the cochlea remains to be investigated through functional experiments. TMEM119 expression in the basal cells of the stria vascularis implies a possible role in the gap junction system of the blood–labyrinth barrier and merits further research.

ADAM10-a "multitasker" in sepsis: focus on its posttranslational target

BACKGROUND

Sepsis has a complex pathogenesis in which the uncontrolled systemic inflammatory response triggered by infection leads to vascular barrier disruption, microcirculation dysfunction and multiple organ dysfunction syndrome. Numerous recent studies reveal that a disintegrin and metalloproteinase 10 (ADAM10) acts as a "molecular scissor" playing a pivotal role in the inflammatory response during sepsis by regulating proteolysis by cleaving various membrane protein substrates, including proinflammatory cytokines, cadherins and Notch, which are involved in intercellular communication. ADAM10 can also act as the cellular receptor for Staphylococcus aureus α-toxin, leading to lethal sepsis. However, its substrate-specific modulation and precise targets in sepsis have not yet to be elucidated.

METHODS

We performed a computer-based online search using PubMed and Google Scholar for published articles concerning ADAM10 and sepsis.

CONCLUSIONS

In this review, we focus on the functions of ADAM10 in sepsis-related complex endothelium-immune cell interactions and microcirculation dysfunction through the diversity of its substrates and its enzymatic activity. In addition, we highlight the posttranslational mechanisms of ADAM10 at specific subcellular sites, or in multimolecular complexes, which will provide the insight to intervene in the pathophysiological process of sepsis caused by ADAM10 dysregulation.

CCL26 in primary biliary cholangitis - Is it a novel disease mediator?

AIM

To verify the role of CX3C chemokine ligand 1 - CX3C chemokine receptor 1 (CX3CL1-CX3CR1) pathway in the pathogenesis of primary biliary cholangitis (PBC). To explore whether CCL26, a novel functional ligand to CX3CR1, participates in the immunological mechanism of PBC.

METHODS

Fifty-nine PBC patients and 54 healthy controls were recruited. Enzyme-linked immunosorbent assay and flow cytometry were used to measure CX3CL1 and CCL26 concentrations in plasma and CX3CR1 expression on peripheral lymphocytes, respectively. Chemotactic effects of CX3CL1 and CCL26 toward lymphocytes were detected by Transwell cell migration assays. CX3CL1 and CCL26 expressions in liver were assessed by immunohistochemical staining. Effects of CX3CL1 and CCL26 on stimulating cytokine production from lymphocytes were evaluated using intracellular flow cytometry.

RESULTS

Significantly elevated CX3CL1 and CCL26 plasma concentration and CX3CR1 expression on CD4⁺ and CD8⁺ T cells were noted in PBC patients. CX3CL1 exhibited chemotactic activity toward CD8⁺ T, natural killer (NK) and NKT cells in a dose-dependent manner while such chemotactic effects were not detected for CCL26. In PBC patients, CX3CL1 and CCL26 were both increasingly expressed in biliary tracts and a concentration gradient of CCL26 in hepatocytes around portal areas was observed. Immobilized CX3CL1 could enhance interferon-γ production from T and NK cells while such effect was not exhibited by soluble CX3CL1 or CCL26.

CONCLUSIONS

CCL26 expression is significantly elevated in plasma and biliary duct of PBC patients, yet does not appear to attract CX3CR1-expressing immune cells. CX3CL1-CX3CR1 pathway promotes the infiltration of T, NK and NKT cells into bile ducts and forms a positive feedback loop with T-helper 1 type cytokines in PBC.

Potential Impact of Prosthetic Biomaterials on the Periodontium: A Comprehensive Review

The success of a prosthetic treatment is closely related to the periodontal health of the individual. The aim of this article was to review and present the importance of prosthetic restorative materials on the condition of the periodontium, the changes that occur in the composition of the subgingival microbiota and the levels of inflammatory markers in gingival crevicular fluid. Articles on the influence of different prosthetic restorative materials on subgingival microbiota and proinflammatory cytokines were searched for using the keywords "prosthetic biomaterials", "fixed prosthesis", "periodontal health", "subgingival microbiota", "periodontal biomarkers" and "gingival crevicular fluid" in PubMed/Medline, Science Direct, Scopus and Google Scholar. The type of material used for prosthesis fabrication together with poor marginal and internal fit can result in changes in the composition of the subgingival microbiota, as well as increased accumulation and retention of dentobacterial plaque, thus favoring the development of periodontal disease and prosthetic treatment failure. Biological markers have helped to understand the inflammatory response of different prosthetic materials on periodontal tissues with the main purpose of improving their clinical application in patients who need them. Metal-free ceramic prostheses induce a lower inflammatory response regardless of the fabrication method; however, the use of CAD/CAM systems is recommended for their fabrication. In addition, it is presumed that metal-ceramic prostheses cause changes in the composition of the subgingival microbiota producing a more dysbiotic biofilm with a higher prevalence of periodontopathogenic bacteria, which may further favor periodontal deterioration.

Sphingosine-1-Phosphate Recruits Macrophages and Microglia and Induces a Pro-Tumorigenic Phenotype That Favors Glioma Progression

Glioblastoma is the most aggressive brain tumor in adults. Treatment failure is predominantly caused by its high invasiveness and its ability to induce a supportive microenvironment. As part of this, a major role for tumor-associated macrophages/microglia (TAMs) in glioblastoma development was recognized. Phospholipids are important players in various fundamental biological processes, including tumor-stroma crosstalk, and the bioactive lipid sphingosine-1-phosphate (S1P) has been linked to glioblastoma cell proliferation, invasion, and survival. Despite the urgent need for better therapeutic approaches, novel strategies targeting sphingolipids in glioblastoma are still poorly explored. Here, we showed that higher amounts of S1P secreted by glioma cells are responsible for an active recruitment of TAMs, mediated by S1P receptor (S1PR) signaling through the modulation of Rac1/RhoA. This resulted in increased infiltration of TAMs in the tumor, which, in turn, triggered their pro-tumorigenic phenotype through the inhibition of NFkB-mediated inflammation. Gene set enrichment analyses showed that such an anti-inflammatory microenvironment correlated with shorter survival of glioblastoma patients. Inhibition of S1P restored a pro-inflammatory phenotype in TAMs and resulted in increased survival of tumor-bearing mice. Taken together, our results establish a crucial role for S1P in fine-tuning the crosstalk between glioma and infiltrating TAMs, thus pointing to the S1P-S1PR axis as an attractive target for glioma treatment.

Cross-platform immunophenotyping of human peripheral blood mononuclear cells with four high-dimensional flow cytometry panels

Immunophenotyping using high dimensional flow cytometry is a central component of human immune system multi-omic studies. We present four high parameter flow cytometry panels for deep immunophenotyping of human peripheral blood mononuclear cells (PBMC). This set of four 25+ color panels include 64 cell surface markers to resolve broad immune compartment populations, as well as activation and memory of specific T, B, natural killer (NK), and myeloid lineages. Common lineage bridging markers are integrated into each panel to allow for inter-panel quality control through major lineage frequency verification. These panels were developed using a five laser BD Symphony A5 conventional cytometer and successfully transferred to a five laser Cytek Aurora spectral cytometer capable of acquiring the panels. Nine representative PBMC samples were stained with the four phenotyping panels and acquired on both instruments to evaluate population frequency and visual staining patterns for gating between the systems. Both instruments produced comparable high quality flow cytometry data and supported our decision to acquire samples on the spectral cytometer moving forward. This modular set of panels and instrument performance metrics provide guidelines for designing flow cytometry experiments suitable for longitudinal or cross-sectional immune profiling.

METABOLIC AND HORMONAL FEATURES OF CHRONIC HEART FAILURE IN PERSONS WITH POST-INFARCTION CARDIOSCLEROSIS WITH TYPE 2 DIABETES MELLITUS AND OBESITY

OBJECTIVE

The aim: To determine the role of lipid metabolism and fractalkin and clusterin in the progression of chronic heart failure in patients with postinfarction cardiosclerosis with concomitant type 2 diabetes and obesity.

PATIENTS AND METHODS

Materials and methods: A retrospective analysis of a comprehensive examination of 67 patients with postinfarction cardiosclerosis with concomitant type 2 diabetes and obesity. All patients were divided into 3 groups depending on the functional class (FC) of CHF: 1 group (n = 22) - patients with CHF II FC; Group 2 (n = 23) - patients with CHF III FC; Group 3 (n = 22) - patients with CHF IV FC. All patients were examined clinically, they were instrumental, biochemical and hormonal examination.

RESULTS

Results: With the progression of CHF from FC II to FC III there is a deterioration of lipid metabolism: a significant increase in cholesterol levels by 5.5%, TG - by 15.7%, LDL cholesterol - by 74.4%, VLDL cholesterol - by 15 , 9%, reduction of HDL cholesterol - by 27.6% (p <0,05). An analysis of the fractal equation showing that ailing on CHF is advised by FC; rіven clusterin -decrease.

CONCLUSION

Conclusions: Classical changes in patients with postinfarction cardiosclerosis with CHF and concomitant type 2 diabetes mellitus and obesity , which are the formation of atherogenic lipid metabolism disorders associated with body weight, as well as changes in the latest indicators such as fractalkin and clusterin , indicating the role of these molecules in the progression of CHF.

Lessons from the Cerebrospinal Fluid Analysis of HTLV-1-Infected Individuals: Biomarkers of Inflammation for HAM/TSP Development

HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a neurodegenerative disease that leads to motor impairment due to a chronic inflammatory process in the central nervous system (CNS). However, the HAM/TSP pathogenesis is not completely clear, and biomarkers to define the disease prognosis are still necessary. Thus, we aimed to identify biomarkers for HAM/TSP and potential mechanisms involved in disease development. To that end, the concentrations of VILIP-1, BDNF, VEGF, β-NGF, TGF-β1, fractalkine/CX3CL1, IL-6, IL-18, and TNF-α, and the soluble forms of TREM-1, TREM-2, and RAGE, were assessed using a multiplex bead-based immunoassay in paired cerebrospinal fluid (CSF) and serum samples from HAM/TSP patients (n = 20), asymptomatic HTLV-1 carriers (AC) (n = 13), and HTLV-1-seronegative individuals (n = 9), with the results analyzed according to the speed of HAM/TSP progression. HAM/TSP patients had elevated fractalkine in the serum but not in the CSF, particularly those with low neuroinflammatory activity (CSF/serum ratio of neopterin <1 and of CXCL10 < 2). HAM/TSP patients with normal CSF levels of neurofilament light chain (NfL) showed elevated β-NGF in serum, and serum BDNF levels were increased in HTLV-1-infected individuals, particularly in HTLV-1 AC. Both HTLV-1 AC and HAM/TSP patients had lower TGF-β1 levels in CSF compared to uninfected individuals, and HAM/TSP patients with active CNS inflammation showed higher CSF levels of IL-18, which correlated with markers of inflammation, neuronal death, and blood−brain-barrier permeability. Although none of the factors evaluated were associated with the speed of HAM/TSP progression, reduced TGF-β1 levels in CSF suggest that suppressive responses to control subclinical and/or active neurodegeneration are impaired, while increased CSF IL-18 indicates the involvement of inflammasome-mediated mechanisms in HAM/TSP development.

Posthemorrhagic hydrocephalus associates with elevated inflammation and CSF hypersecretion via activation of choroidal transporters

INTRODUCTION

Posthemorrhagic hydrocephalus (PHH) often develops following hemorrhagic events such as intraventricular hemorrhage (IVH) and subarachnoid hemorrhage (SAH). Treatment is limited to surgical diversion of the cerebrospinal fluid (CSF) since no efficient pharmacological therapies are available. This limitation follows from our incomplete knowledge of the molecular mechanisms underlying the ventriculomegaly characteristic of PHH. Here, we aimed to elucidate the molecular coupling between a hemorrhagic event and the subsequent PHH development, and reveal the inflammatory profile of the PHH pathogenesis.

METHODS

CSF obtained from patients with SAH was analyzed for inflammatory markers using the proximity extension assay (PEA) technique. We employed an in vivo rat model of IVH to determine ventricular size, brain water content, intracranial pressure, and CSF secretion rate, as well as for transcriptomic analysis. Ex vivo radio-isotope assays of choroid plexus transport were employed to determine the direct effect of choroidal exposure to blood and inflammatory markers, both with acutely isolated choroid plexus and after prolonged exposure obtained with viable choroid plexus kept in tissue culture conditions.

RESULTS

The rat model of IVH demonstrated PHH and associated CSF hypersecretion. The Na+/K+-ATPase activity was enhanced in choroid plexus isolated from IVH rats, but not directly stimulated by blood components. Inflammatory markers that were elevated in SAH patient CSF acted on immune receptors upregulated in IVH rat choroid plexus and caused Na+/K+/2Cl- cotransporter 1 (NKCC1) hyperactivity in ex vivo experimental conditions.

CONCLUSIONS

CSF hypersecretion may contribute to PHH development, likely due to hyperactivity of choroid plexus transporters. The hemorrhage-induced inflammation detected in CSF and in the choroid plexus tissue may represent the underlying pathology. Therapeutic targeting of such pathways may be employed in future treatment strategies towards PHH patients.

The Role of Vitamin D in Alzheimer’s Disease: A Transcriptional Regulator of Amyloidopathy and Gliopathy

Alzheimer’s disease (AD) is characterized by amyloid-beta (Aβ) accumulation and cognitive mental decline. Epidemiological studies have suggested an association between low serum vitamin D levels and an increased risk of AD. Vitamin D regulates gene expression via the vitamin D receptor, a nuclear ligand-dependent transcription factor. However, the molecular mechanism underlying the pathogenic and therapeutic effects of vitamin D on AD is not fully understood yet. To better understand how vitamin D regulates the expression of genes related to AD pathology, first, we induced vitamin D deficiency in 5xFAD mice by providing a vitamin-D-deficient diet and observed the changes in the mRNA level of genes related to Aβ processing, which resulted in an increase in the Aβ load in the brain. The vitamin D-deficient diet also suppressed the expression of genes for microglial Aβ phagocytosis. Interestingly, vitamin D deficiency in the early stage of AD resulted in earlier memory impairment. In addition, we administered vitamin D intraperitoneally to 5xFAD mice with a normal diet and found lower Aβ levels with the suppressed expression of genes for Aβ generation and observed improved memory function, which may be potentially associated with reduced MAO-B expression. These findings strongly suggest the role of vitamin D as a crucial disease-modifying factor that may modulate the amyloid pathology with regard to reducing AD symptoms.

Microglia as Therapeutic Target for Radiation-Induced Brain Injury

Radiation-induced brain injury (RIBI) after radiotherapy has become an increasingly important factor affecting the prognosis of patients with head and neck tumor. With the delivery of high doses of radiation to brain tissue, microglia rapidly transit to a pro-inflammatory phenotype, upregulate phagocytic machinery, and reduce the release of neurotrophic factors. Persistently activated microglia mediate the progression of chronic neuroinflammation, which may inhibit brain neurogenesis leading to the occurrence of neurocognitive disorders at the advanced stage of RIBI. Fully understanding the microglial pathophysiology and cellular and molecular mechanisms after irradiation may facilitate the development of novel therapy by targeting microglia to prevent RIBI and subsequent neurological and neuropsychiatric disorders.

Intestinal fatty acid binding protein (I-FABP) and CXC3L1 evaluation as biomarkers for patients at high-risk for coeliac disease in Johannesburg, South Africa

Coeliac disease (CD) is an autoimmune disorder and one of the few gastroenteropathies with accurate serological testing. CD serology has decreased accuracy for patients on a gluten-free diet and for monitoring mucosal healing. New ancillary tests would, therefore, be useful. Intestinal Fatty Acid Binding Protein (I-FABP) and CX3CL1 (Fractalkine) are two promising biomarkers for CD but haven't been examined in patients who are at a high-risk for CD such as patients with type one diabetes (TID). This study, therefore, aimed to investigate serum levels of I-FABP and CX3CL1 in a cohort of South African patients with TID at a high-risk of developing CD. The serum I-FABP levels were significantly higher in CD-positive patients compared to CD-negative individuals (p = 0.03). No significant differences in the serum CX3CL1 levels were detected although this may reflect the impact of the comorbid autoimmune diseases had on the serum CX3CL1 levels. In conclusion, this study is the first to assess the levels of these biomarkers in a multiethnic population with comorbid autoimmune disease and determined I-FABP to be the more promising biomarker in such clinical contexts. Future research should focus on a diverse biomarker panel and longitudinal follow-up of patients at a high-risk for CD.

Chemokines and NSCLC: Emerging role in prognosis, heterogeneity, and therapeutics

Lung cancer persists to contribute to one-quarter of cancer-associated deaths. Among the different histologies, non-small cell lung cancer (NSCLC) alone accounts for 85% of the cases. The development of therapies involving immune checkpoint inhibitors and angiogenesis inhibitors has increased patients' survival probability and reduced mortality rates. Developing targeted therapies against essential genetic alterations also translates to better treatment strategies. But the benefits still seem farfetched due to the development of drug resistance and refractory tumors. In this review, we have highlighted the interplay of different tumor microenvironment components, essentially discussing the chemokine families (CC, CXC, C, and CX3C) that regulate the tumor biology in NSCLC and promote tumor growth, metastasis, and associated heterogeneity. The development of therapeutics and prognostic markers is a complex and multipronged approach. However, some essential chemokines can act as critical players for being considered potential prognostic markers and therapeutic targets.

Differential immune landscapes in appendicular versus axial skeleton

Roughly 400,000 people in the U.S. are living with bone metastases, the vast majority occurring in the spine. Metastases to the spine result in fractures, pain, paralysis, and significant health care costs. This predilection for cancer to metastasize to the bone is seen across most cancer histologies, with the greatest incidence seen in prostate, breast, and lung cancer. The molecular process involved in this predilection for axial versus appendicular skeleton is not fully understood, although it is likely that a combination of tumor and local micro-environmental factors plays a role. Immune cells are an important constituent of the bone marrow microenvironment and many of these cells have been shown to play a significant role in tumor growth and progression in soft tissue and bone disease. With this in mind, we sought to examine the differences in immune landscape between axial and appendicular bones in the normal noncancerous setting in order to obtain an understanding of these landscapes. To accomplish this, we utilized mass cytometry by time-of-flight (CyTOF) to examine differences in the immune cell landscapes between the long bone and vertebral body bone marrow from patient clinical samples and C57BL/6J mice. We demonstrate significant differences between immune populations in both murine and human marrow with a predominance of myeloid progenitor cells in the spine. Additionally, cytokine analysis revealed differences in concentrations favoring a more myeloid enriched population of cells in the vertebral body bone marrow. These differences could have clinical implications with respect to the distribution and permissive growth of bone metastases.

Modulatory Effects of Fractalkine on Inflammatory Response and Iron Metabolism of Lipopolysaccharide and Lipoteichoic Acid-Activated THP-1 Macrophages

Fractalkine (CX3CL1) acts as a chemokine as well as a regulator of iron metabolism. Fractalkine binds CX3CR1, the fractalkine receptor on the surface of monocytes/macrophages regulating different intracellular signalling pathways such as mitogen-activated protein kinase (MAPK), phospholipase C (PLC) and NFκB contributing to the production of pro-inflammatory cytokine synthesis, and the regulation of cell growth, differentiation, proliferation and metabolism. In this study, we focused on the modulatory effects of fractalkine on the immune response and on the iron metabolism of Escherichia coli and Pseudomonas aeruginosa lipopolysaccharides (LPS) and Staphylococcus aureus lipoteichoic acid (LTA) activated THP-1 cells to get a deeper insight into the role of soluble fractalkine in the regulation of the innate immune system. Pro-inflammatory cytokine secretions of the fractalkine-treated, LPS/LTA-treated, and co-treated THP-1 cells were determined using ELISArray and ELISA measurements. We analysed the protein expression levels of signalling molecules regulated by CX3CR1 as well as hepcidin, the major iron regulatory hormone, the iron transporters, the iron storage proteins and mitochondrial iron utilization. The results showed that fractalkine treatment alone did not affect the pro-inflammatory cytokine secretion, but it was proposed to act as a regulator of the iron metabolism of THP-1 cells. In the case of two different LPS and one type of LTA with fractalkine co-treatments, fractalkine was able to alter the levels of signalling proteins (NFκB, PSTAT3, Nrf2/Keap-1) regulating the expression of pro-inflammatory cytokines as well as hepcidin, and the iron storage and utilization of the THP-1 cells.

Human microglial models to study HIV infection and neuropathogenesis: a literature overview and comparative analyses

HIV persistence in the CNS despite antiretroviral therapy may cause neurological disorders and poses a critical challenge for HIV cure. Understanding the pathobiology of HIV-infected microglia, the main viral CNS reservoir, is imperative. Here, we provide a comprehensive comparison of human microglial culture models: cultured primary microglia (pMG), microglial cell lines, monocyte-derived microglia (MDMi), stem cell-derived microglia (iPSC-MG), and microglia grown in 3D cerebral organoids (oMG) as potential model systems to advance HIV research on microglia. Functional characterization revealed phagocytic capabilities and responsiveness to LPS across all models. Microglial transcriptome profiles of uncultured pMG showed the highest similarity to cultured pMG and oMG, followed by iPSC-MG and then MDMi. Direct comparison of HIV infection showed a striking difference, with high levels of viral replication in cultured pMG and MDMi and relatively low levels in oMG resembling HIV infection observed in post-mortem biopsies, while the SV40 and HMC3 cell lines did not support HIV infection. Altogether, based on transcriptional similarities to uncultured pMG and susceptibility to HIV infection, MDMi may serve as a first screening tool, whereas oMG, cultured pMG, and iPSC-MG provide more representative microglial culture models for HIV research. The use of current human microglial cell lines (SV40, HMC3) is not recommended.

Immunogenetic aspects of idiopathic recurrent miscarriage in the Kazakh population

There are numerous scientific studies of recurrent miscarriage (RM) with possible causes, such as fetal chromosomal abnormalities, infectious agents, adverse environmental factors, bad habits, anatomical defects, thrombophilic disorders, etc. However, RM causes in 50% of cases remain unknown. These RM cases do not have any explainable etiology, and they require in-depth etiopathogenesis study, thus they are considered idiopathic RM. The purpose of this research is to study polymorphisms relationship of the immune response genes CX3CR1 (rs3732379, Val249Ile), CTLA4 (rs3087243, CT60 G/A), and HLA DQA1, DQB1, DRB1 (major histocompatibility complex, class II) with the idiopathic form of recurrent miscarriage (iRM) development in Kazakh population. Independent replicative TagMan genotyping for 302 patients with iRM and 300 women with normal reproduction was performed. It has been shown that carriage of unfavorable genotypes (Val/Ile, Val/Val) by the Val249Ile polymorphism of the CX3CR1 gene increases the risk of developing iRM by 1.43 times. Search for associations of genes allelic variants of HLA class 2 complex with iRM revealed *501 allele in DQA1 locus, *0301 in DQB1 locus, *10, *12, *15, *16 alleles in DRB1 locus, which increases the risk of developing iRM in Kazakh population with OR from 1.34 to 4.5. As a result of the study, obtained highly significant associations of immune response genes with the development of iRM in the Kazakh population indicate the possible involvement of the immune system interaction of mother cells with syncytiotrophoblast, which is realized by vascularization defects, defective embryo implantation, and leads to early pregnancies’ termination.

ApoA-I mimetics reduce systemic and gut inflammation in chronic treated HIV

Novel therapeutic strategies are needed to attenuate increased systemic and gut inflammation that contribute to morbidity and mortality in chronic HIV infection despite potent antiretroviral therapy (ART). The goal of this study is to use preclinical models of chronic treated HIV to determine whether the antioxidant and anti-inflammatory apoA-I mimetic peptides 6F and 4F attenuate systemic and gut inflammation in chronic HIV. We used two humanized murine models of HIV infection and gut explants from 10 uninfected and 10 HIV infected persons on potent ART, to determine the in vivo and ex vivo impact of apoA-I mimetics on systemic and intestinal inflammation in HIV. When compared to HIV infected humanized mice treated with ART alone, mice on oral apoA-I mimetic peptide 6F with ART had consistently reduced plasma and gut tissue cytokines (TNF-α, IL-6) and chemokines (CX3CL1) that are products of ADAM17 sheddase activity. Oral 6F attenuated gut protein levels of ADAM17 that were increased in HIV-1 infected mice on potent ART compared to uninfected mice. Adding oxidized lipoproteins and endotoxin (LPS) ex vivo to gut explants from HIV infected persons increased levels of ADAM17 in myeloid and intestinal cells, which increased TNF-α and CX3CL1. Both 4F and 6F attenuated these changes. Our preclinical data suggest that apoA-I mimetic peptides provide a novel therapeutic strategy that can target increased protein levels of ADAM17 and its sheddase activity that contribute to intestinal and systemic inflammation in treated HIV. The large repertoire of inflammatory mediators involved in ADAM17 sheddase activity places it as a pivotal orchestrator of several inflammatory pathways associated with morbidity in chronic treated HIV that make it an attractive therapeutic target.

Principal component analysis of salivary cytokines and hormones in the acute stress response

The acute stress response is characterized by activation of multiple interconnected systems in the body, resulting in the release of a flood of hormones and immune mediators into circulation. In addition to detection of these molecules in the serum, saliva can serve as a source of these markers as well and can be collected in a non-invasive way. The complete profile of salivary biomarkers associated with the hypothalamic pituitary adrenal/gonadal axes and the immune system during the acute stress response has not been fully elucidated. In a cohort of 62 first responders engaged in a stress training exercise, we set out to determine patterns of cytokine, chemokine and hormone shifts during the acute stress response. Salivary samples were collected immediately before (pre-stress), immediately after (post-stress) and 1 h after the stress test (recovery). Multiplex ELISA panels of 42 cytokines and 6 steroid and thyroid hormones were used to determine concentrations of these biomarkers during the three aforementioned time points. Principal components analysis was conducted to determine patterns in the large data sets collected. In our ≥0.3 loading principal components analysis, for pre-stress vs. post, post-stress vs. recovery and pre-stress vs. recovery, a total of three, four and three factors accounted for 56.6, 68.34, and 61.70% of the biomarker variation for each phase respectively. In the ≥0.7 loading principal components analysis, three, four and three factors were found for pre-stress vs. post, post-stress vs. recovery and pre-stress vs. recovery stages, respectively. Of note, in our ≥0.3 loading principal components analysis, MCP1 was present in all three factors from pre-stress to post-stress, and fractalkine was found to be in all four factors post-stress vs. recovery and pre vs. recovery from stress. Additionally, hormones testosterone, estradiol, T4 and T3 grouped together consistently in the same factor for all phases of acute stress in both ≥0.3 and ≥0.7 principal components analysis. Overall, our results identified specific patterns of immune markers and hormones that shift during acute stress and warrant further investigation to understand their mechanistic role in regulating the stress response.