Natural killer (NK) cells are central to antiviral immunity through a balance of activating and inhibitory receptors, including killer immunoglobulin-like receptors (KIRs). We have previously observed that an increased frequency of the inhibitory receptor KIR2DL2 and its ligand HLA-C1 is associated with heightened susceptibility to human herpesvirus (HHV) infection, supporting a role for KIR-mediated NK cell regulation in host-virus interactions. We investigated whether the co-infection of SARS-CoV-2 and human herpesvirus 6 (HHV-6) might be connected to the expression of KIR2DL2/HLA-C1. We analyzed 110 SARS-CoV-2-positive subjects and 109 SARS-CoV-2-negative subjects for the KIR2DL2 and HLA-C1 genotype and for HHV-6A/B reactivation in plasma samples. SARS-CoV-2-positive subjects showed a significantly higher frequency of the KIR2DL2/HLA-C1 haplotype and increased reactivation of HHV-6A. Among deceased and comorbid patients, the co-occurrence of the KIR2DL2/HLA-C1 haplotype and HHV-6A DNAemia was more frequent, particularly in those with cardiovascular disorders. These findings suggest that the KIR2DL2/HLA-C1 haplotype might promote NK cell inhibition, facilitating HHV-6A persistence and contributing to immune dysregulation during SARS-CoV-2 infection. The combined presence of KIR2DL2/HLA-C1 and HHV-6A may, therefore, represent a molecular signature of COVID-19 outcomes.
Impaired immune clearance of senescent fibroblasts is a putative driver of pulmonary fibrosis. Exhausted natural killer (NK) cells have been implicated in this process, yet the underlying immune evasion mechanisms remain poorly understood. Using single-cell RNA sequencing (scRNA-seq) and spectral flow cytometry, we identified natural killer group 2 member A (NKG2A) as the predominant inhibitory checkpoint receptor expressed on NK cells in fibrotic lung diseases. Mechanistic in vitro coculture studies showed that NK cell suppression was mediated by senescent fibroblasts expressing human leukocyte antigen-E (HLA-E), the high-affinity ligand for NKG2A. scRNA-seq analysis of lungs from patients with idiopathic pulmonary fibrosis (IPF) further identified selective HLA-E expression in senescent HAS1+ fibroblast subsets. Further, spatial transcriptomics and multiplex immunofluorescence of patient lungs demonstrated that HLA-E+ fibroblasts were positioned at the periphery of fibroblast foci adjacent to NKG2A+ NK cells, establishing an immune-privileged niche. In contrast, extracellular matrix-producing myofibroblasts at the core of fibrotic foci lacked HLA-E and exhibited minimal NK engagement. In vivo, therapeutic blockade of NKG2A restored NK cell function, promoted clearance of senescent fibroblasts, and promoted fibrosis resolution in the bleomycin-induced mouse model. Monalizumab, a clinical-grade NKG2A inhibitor, reactivated patient-derived NK cells and enhanced lysis of human senescent fibroblasts in vitro. Together, these findings uncover a spatially restricted immune checkpoint axis that allows senescent fibroblasts to evade immune NK surveillance. Targeting the HLA-E/NKG2A axis represents a promising therapeutic strategy to restore NK cell-mediated immune clearance of senescent fibroblasts and reverse pulmonary fibrosis.
In the original publication [...].
In recent decades, there has been significant worldwide interest in the emergence of a new invasive species known as Achatina fulica. This is due to its dangerous habits for the environment, its biological characteristics and the fact that it is the intermediate host of several nematode parasites, such as Angiostrongylus cantonensis. This land snail species is native to tropical African countries, but has been introduced, accidentally or deliberately, to other parts of the world to be used for different purposes and is now established in a large part of the tropics. Since the 1980s, hundreds of researchers have been interested in the beneficial properties of its mucus, ranging from the antimicrobial and anticancer properties to the use of its powdered shell as a biocatalyst. This literature review aims to objectively describe the positive and negative aspects associated with the spread of A. fulica, highlighting in particular the opportunities for the local populations deriving from a conscious exploitation of this mollusc.
Artificial tear substitutes are key elements in the first-line treatment of dry eye disease (DED). We hypothesized that GlicoPro®, a new multimolecular complex based on proteins, sulfured and unsulfured glycosaminoglycans and opiorphin, was able to significantly improve the effect of hydroxypropyl-methylcellulose (HPMC) eyedrops in treating DED. We performed an in vitro experiment and a clinical study, comparing an HPMC + GlicoPro®-based to an HPMC-based ophthalmic formulation (similar kinematic viscosity and comparable HPMC concentration). An in vitro dry eye model was established by inducing hyperosmolarity in the base medium of human corneal epithelial cells HCE-2. After treatment with ophthalmic formulations, the expression levels of inflammatory cytokines and enzymes (IL-20, IL-1β, TNF-α, IL-6, IL-8, MMP-9, and MCP-1) was measured by real-time polymerase chain reaction. Moreover, we performed a single-blind randomized 1:1 clinical trial, aimed to compare the efficacy of the two formulations instilled four times per day (QID), in treating mild-to-moderate DED. Symptoms (Ocular Surface Disease Index and Symptom Assessment iN Dry Eye), clinical signs, and ocular surface imaging data were assessed at baseline and after 1 and 3 months of treatment. In vitro experiment: under hyperosmotic conditions, corneal epithelial cells upregulated the expression of inflammatory cytokines IL-20, IL-1β, TNF-α, IL-6, and IL-8. Treatment with HPMC + GlicoPro® significantly decreased the expression of all inflammatory markers tested, including cytokines, MMP-9, and MCP-1 (P < 0.05). Clinical study: the HPMC + GlicoPro® formulation showed a significantly higher effect in improving symptoms (overall treatment effect: P < 0.001), tear film stability, and markers of inflammation on corneal confocal microscopy (P < 0.01). Both in vitro and clinical data provided evidence supporting the role of GlicoPro® in improving the effect of HPMC in DED treatment. NCT06726525.
Background: Gastric cancer (GC) remains a serious health concern and is characterized by a multifactorial etiology involving both genetic and epigenetic factors. The aim of the current study was to examine the relationship between Human leukocyte antigen (HLA)-G 3'UTR polymorphisms and the expression of HLA-G in both tumor tissues and plasma samples from patients with GC in the Tunisian population. Methods: HLA-G 3'UTR polymorphisms (14pb Insertion/deletion and + 3142C/G) were identified by polymerase chain reaction (PCR) or Sanger sequencing. Plasma levels of sHLA-G (total sHLA-G, shed HLA-G1 and HLA-G5) were determined. Immunohistochemistry was used to evaluate the expression of HLA-G in tumor tissues. Results: The Del/Del genotype and Del allele frequencies were different between GC patients and healthy donors (HD) (OR [95 % CI] = 2.483 [1.070-5.410], p = 0.025 vs. OR [95 % CI] = 1.537 [0.924-2.584], p = 0.099; respectively). The C/C genotype and C allele frequencies were significantly greater in GC patients than in HD (OR [95 % CI] = 2.269[0.1.070-4.904], p = 0.033 vs. OR [95 % CI] = 1.746[1.045-2.878], p = 0.034; respectively). Interestingly, the Del/Del genotype and Del allele were significantly associated with an increased risk of GC in patients aged >= 55 years at diagnosis. HLA-G was highly expressed in GC tissues, particularly in tissues with advanced tumor invasion (T3 + T4). Compared with HD, GC patients had higher soluble HLA-G, shed HLA-G1 and HLA-G5 levels (Mann-Whitney: p = 0.001, p = 0.001 and p = 0.643, respectively). Assessment of patients' survival by Kaplan-Meier analysis indicated that the Del allele was significantly associated with reduced overall survival (OS) in GC patients at advanced stages III + IV (p = 0.043). Conclusions: These results suggest that HLA-G 3'UTR polymorphisms are associated with GC susceptibility in Tunisian population. The expression of HLA-G in both the tissue and plasma may play an important role in the development and progression of GC. Therefore, the current study supported the recommendation of investigating HLA-G 3'UTR polymorphisms in GC and indicated that HLA-G molecules could serve as promising therapeutic targets in GC.
Flaviviruses, such as dengue and West Nile, cause diverse clinical symptoms and trigger varied clinical outcomes, partly driven by the secreted nonstructural sNS1 protein (sNS1). This study examined how sNS1 from neurotropic and hemorrhagic flaviviruses affects coagulation and inflammation using human monocytic (THP-1) cells. sNS1 from neurotropic viruses (e.g., West Nile, Japanese encephalitis) increased tissue factor (TF) expression and the release of TF-bearing microvesicles, promoting procoagulant activity. In contrast, sNS1 from hemorrhagic viruses (e.g., dengue) showed anticoagulant effects. These divergent responses correlated with the virus-specific modulation of interleukin-6 (IL-6), suggesting that inflammation plays a central role in sNS1-mediated vascular changes. The findings identify sNS1 as a key virulence factor influencing flavivirus pathogenesis through hemostatic and immune pathways, offering a potential target for therapeutic intervention.
Recent observations highlight a notable surge in West Nile Virus (WNV) infections in Europe that can lead to neuroinvasive consequences associated with neurodegeneration, mainly triggered by WNV Non-Structural protein 1 (NS1). During viral replication, various protein-protein interactions take place, allowing viral proteins to interact with host factors. NS1 is actively secreted in the bloodstream by infected cells and is known to affect endothelial permeability and host immune response. Focusing on the recently discovered antimicrobial roles of Amyloid-Beta (Aβ) in the context Central Nervous System (CNS), we connected WNV late pathology to overlapping features encountered in neurodegenerative diseases. In fact, CNS viral infections, or presence of specific viral components, activate glial cells, which in turn increase Aβ expression as an antiviral mechanism, leading to Aβ accumulation and neuronal damage. Considering West Nile neuroinvasive disease (WNND) as a possible complication of WNV infection, we investigated the impact of soluble WNV (s)NS1 on glial and neuronal cells, in 2D and 3D in vitro models. We reported an increased Aβ deposition after WNV sNS1 treatment, particularly of Aβ-142 isoform, and increased glial activation with a subsequent neurotoxicity. These findings underscore the crucial role of sNS1 in CNS-related effects during WNV infection, suggesting a novel pathogenetic role.
Background:HLA-G is associated with cancer cell escape. The 3'UTR polymorphism is involved in the regulation of membrane-bound HLA-G and soluble HLA-G proteins. The aim of our study was to assess the association of the HLA-G 14-bp insertion (I)/deletion (D) polymorphism with cancer susceptibility and its interaction with clinicopathological features and environmental factors. Methods:A meta-analysis was performed to investigate the association between the HLA-G 14-bp I/D polymorphism and different types of cancers according to the Prisma guidelines. Results:Thirty-nine publications that studied the 14-bp I/D polymorphism in cancers met our inclusion criteria. The findings of the meta-analysis showed a significant association between the 14-bp I/D polymorphism and cancer risk under the allelic contrast model D vs. I (OR = 1,112, 95 % CI = 1,009-1,227; P = 0,033) suggesting that the D allele was a risk factor for cancer susceptibility. Stratification by cancer type demonstrated a significant association of the 14-bp I/D polymorphism with breast cancer under the D vs. I contrast allele model (OR = 1,267, 95 % CI = 1,028-1,563; P = 0,027). No significant association was found for digestive, cervical, haematological and thyroid cancers. A comparison of groups stratified by ethnicity showed a significant association for Caucasians under the D vs. I model (OR = 1,147, 95 % CI = 1,002-1,313; P = 0,047); and for mixed ethnicities under the DD + DI vs. II (OR = 1,388, 95 % CI = 1,083-1,780; P = 0,010) and DI vs. II (OR = 1,402, 95 % CI = 1,077-1,824; P = 0,012) models. A comparison of cancer risks associated with the 14-bp I/D polymorphism according to geographic location revealed significant risks for the D allele and DD genotype in North Africa, the Middle East and South America. However, no significant susceptibility to cancer associated with the 14-bp I/D polymorphism was shown for Europe and North Asia. The findings of a meta-analysis of subgroups by disease stage showed a significant association in both early and advanced stages, with the 14-bp deletion variant being a risk factor. Similarly, a significant cancer risk was shown for the 14-bp deletion variant in both low- and high-grade cancers. Finally, the risk associated with the 14-bp I/D polymorphism was higher in cancers with concomitant viral infection with human papillomavirus (HPV), hepatitis B virus (HBV) or hepatitis C virus (HCV). Conclusion:The findings of the overall meta-analysis showed a significant association between the HLA-G 14-bp I/D polymorphism and cancer susceptibility. The findings stratified analysis and subgroup comparisons showed that the 14-bp I/D deletion variant was associated with an increased risk of breast cancer. The HLA-G 14-bp I/D polymorphism may interact with individual and clinicopathological factors to alter cancer risk. These promising findings for cancer risk provide the basis for further studies that explore 14bp I/D polymorphism in cancer screening and immunotherapeutic approach.
Human leukocyte antigen-G (HLA-G) molecules are non-classical HLA class I antigens with an important role in pregnancy immune regulation and inflammation control. Soluble HLA-G proteins can be generated through two mechanisms: alternative splicing and proteolytic release, which is known to be metalloprotease mediated. Among this class of enzymes, matrix metalloproteinases (MMPs) might be involved in the HLA-G1 membrane cleavage. Of particular interest are MMP-2 and MMP-9, which regulate the inflammatory process by cytokine and chemokine modulation. We evaluated the effect of MMP-9 and MMP-2 on HLA-G1 membrane shedding. In particular, we analyzed the in vitro effect of these two gelatinases on the secretion of HLA-G1 via proteolytic cleavage in 221-G1-transfected cell line, in JEG3 cell line, and in peripheral blood mononuclear cells. The results obtained by both cell lines showed the role of MMP-2 in HLA-G1 shedding. On the contrary, MMP-9 was not involved in this process. In addition, we identified three possible highly specific cleavage sites for MMP-2, whereas none were detected for MMP-9. This study suggests an effective link between MMP-2 and HLA-G1 shedding, increasing our knowledge on the regulatory machinery beyond HLA-G regulation in physiological and pathological conditions.
Background: A neuroinflammatory disease such as Alzheimer’s disease, presents a significant challenge in neurotherapeutics, particularly due to the complex etiology and allostatic factors, referred to as CNS stressors, that accelerate the development and progression of the disease. These CNS stressors include cerebral hypo-glucose metabolism, hyperinsulinemia, mitochondrial dysfunction, oxidative stress, impairment of neuronal autophagy, hypoxic insults and neuroinflammation. This study aims to explore the efficacy and safety of DAG-MAG-ΒHB, a novel ketone diester, in mitigating these risk factors by sustaining therapeutic ketosis, independent of conventional metabolic pathways. Methods: We evaluated the intestinal absorption of DAG-MAG-ΒHB and the metabolic impact in human microglial cells. Utilizing the HMC3 human microglia cell line, we examined the compound’s effect on cellular viability, Acetyl-CoA and ATP levels, and key metabolic enzymes under hypoglycemia. Additionally, we assessed the impact of DAG-AG-ΒHB on inflammasome activation, mitochondrial activity, ROS levels, inflammation and phagocytic rates. Results: DAG-MAG-ΒHB showed a high rate of intestinal absorption and no cytotoxic effect. In vitro, DAG-MAG-ΒHB enhanced cell viability, preserved morphological integrity, and maintained elevated Acetyl-CoA and ATP levels under hypoglycemic conditions. DAG-MAG-ΒHB increased the activity of BDH1 and SCOT, indicating ATP production via a ketolytic pathway. DAG-MAG-ΒHB showed remarkable resilience against low glucose condition by inhibiting NLRP3 inflammasome activation. Conclusions: In summary, DAG-MAG-ΒHB emerges as a promising treatment for neuroinflammatory conditions. It enhances cellular health under varying metabolic states and exhibits neuroprotective properties against low glucose conditions. These attributes indicate its potential as an effective component in managing neuroinflammatory diseases, addressing their complex progression.
Significance: Nicotinamide adenine dinucleotide (NADH) represents the reduced form of NAD+, and together they constitute the two forms of the nicotinamide adenine dinucleotide whose balance is named as the NAD+/NADH ratio. NAD+/NADH ratio is mainly involved in redox reactions since both the molecules are responsible forcarrying electrons to maintain redox homeostasis. Recent Advances: NADH acts as a reducing agent, and one of the most known processes exploiting NADH function is energy metabolism. The two main pathways generating energy and involving NADH are glycolysis and oxidative phosphorylation, occurring in cell cytosol and in the mitochondrial matrix, respectively. Critical Issues: Although NADH is primarily produced through the reduction of NAD+ and consumed by its own oxidation, several are the biosynthetic and consumption pathways, reflecting the NADH role in multiple cellular processes. This review gathers all the main current data referring to NADH incorrelation with metabolic and cellular pathways, such as its coenzyme activity, effect in cell death, and on modulating redox and calcium homeostasis. Future Directions: Gene expression control, as well as the potential impact on neurodegenerative, cardiac disorders and infections, suggest NADH application in clinical settings.Thorough clinical trials and continued investigation into the long-term impacts of NADH are crucial to validate its effectiveness and safety, thereby facilitating its wider acceptance as a therapeutic option in medical practice.
Background: Coagulation decompensation is one of the complications most frequently encountered in COVID-19 patients with a poor prognosis or long-COVID syndrome, possibly due to the persistence of SARS-CoV-2 infection in the cardiovascular system. To date, the mechanism underlying the alteration of the coagulation cascade in COVID-19 patients remains misunderstood and the anticoagulant protein S (PROS1) has been described as a potential risk factor for complications related to COVID-19, due to PLpro SARS-CoV-2 enzyme proteolysis. Methods: Biopsies and blood samples were collected from SARS-CoV-2 positive and negative swab test subjects with coagulopathies (peripheral arterial thrombosis), and SARS-CoV-2 presence, ACE2 and CD147 expression, and plasmatic levels of PROS1 were evaluated. Results: We reported a significant decrease of plasmatic PROS1 in the coagulopathic SARS-CoV-2 swab positive cohort, in association with SARS-CoV-2 in situ infection and CD147 peculiar expression. These data suggested that SARS-CoV-2 associated thrombotic/ischemic events might involve PROS1 cleavage by viral PLpro directly in the site of infection, leading to the loss of its anticoagulant function. Conclusions: Based on this evidence, the identification of predisposing factors, such as CD147 increased expression, and the use of PLpro inhibitors to preserve PROS1 function, might be useful for COVID-19 coagulopathies management.
Background:Moxifloxacin is a bactericidal methoxyquinolone used for the treatment of conjunctivitis and prophylactic therapy in cataract and refractive surgeries. Chloramphenicol is a bacteriostatic organochlorine introduced into clinical practice in 1948 and used mainly in topical preparations because of its known toxicity. Objectives:The study aimed to evaluate the in vitro antibacterial effect and the ocular cytotoxicity of these broad-spectrum antibiotics. Methods:Antimicrobic activity was tested on 4 bacteria strains (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis), and determined through calculation of MIC and half inhibitory concentration for each microorganism. Antibacterial activity was determined by microdilution method after 24 hours' incubation with 2-fold serial dilutions (2.5 mg/mL to 4.883 µg/mL) of moxifloxacin and chloramphenicol. Disk diffusion test were performed according to European Committee on Antimicrobial Susceptibility Testing methodology. Biofilm formation inhibition and biofilm eradication concentration assay were conducted for P aeruginosa and S epidermidis using the microdilution method. Cytotoxicity of antibiotics was evaluated by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) colorimetric assay on human corneal cell. Results:Cytotoxicity of antibiotics was evaluated on human epithelial corneal cells after 4 hours treatment by viability assay. Results showed that corneal cell viability was significantly higher after moxifloxacin treatment compared with chloramphenicol (P < 0.01). Moxifloxacin is characterized by a significantly lower MIC and half inhibitory concentration values and a larger inhibition zone for all the strain tested, with high performance in controlling gram-negative growth, compared with chloramphenicol. Moreover, moxifloxacin showed higher activity compared with chloramphenicol in the inhibition of biofilm formation and in the disruption of biofilm, especially against S epidermidis biofilm. Conclusions:The lower corneal cell toxicity and the broader spectrum of antibacterial activity observed with moxifloxacin suggests its use in ophthalmic solution for the treatment of bacterial eye infections.
Naringenin (NRG) is a flavanone characterized by potential neuroprotective properties, even if low water solubility and poor oral bioavailability limit the ability of this compound to target the central nervous system. As an attempt to overcome these limitations, it is here described the synthesis and characterization of a cocrystal obtained with NRG and betaine (BTN) using gas antisolvent (GAS) technique. The ability of NRG, its cocrystal and the parent physical mixture to permeate across the intestinal and the blood-brain (BBB) barriers was simulated in vitro by using monolayers obtained by IEC-6 cells and a model established by ECV 304, respectively. It is evidenced that the NRG: BTN cocrystal improves both the solubility and dissolution rate of NRG, potentially allowing to enhance its oral bioavailability. Moreover, the results of viability studies performed on IEC-6 cells suggest that low doses of cocrystal frequently administered are required for absorption to be efficient and safe. The study also suggests a synergistic effect of NRG and BTN for the cocrystal and physical mixture in enhancing NRG permeation through the BBB. These results indicate that the NRG:BTN cocrystal is potentially useful for the brain targeting of NRG, following its oral administration.
Virus-associated chronic inflammation may contribute to autoimmunity in a number of diseases. In the brain, autoimmune encephalitis appears related to fluctuating reactivation states of neurotropic viruses. In addition, viral miRNAs and proteins can be transmitted via exosomes, which constitute novel but highly relevant mediators of cellular communication. The current study questioned the role of HSV-1-encoded and host-derived miRNAs in cerebrospinal fluid (CSF)-derived exosomes, enriched from stress-induced neuroinflammatory diseases, mainly subarachnoid hemorrhage (SAH), psychiatric disorders (AF and SZ), and various other neuroinflammatory diseases. The results were compared with CSF exosomes from control donors devoid of any neuroinflammatory pathology. Serology proved positive, but variable immunity against herpesviruses in the majority of patients, except controls. Selective ultrastructural examinations identified distinct, herpesvirus-like particles in CSF-derived lymphocytes and monocytes. The likely release of extracellular vesicles and exosomes was most frequently observed from CSF monocytes. The exosomes released were structurally similar to highly purified stem-cell-derived exosomes. Exosomal RNA was quantified for HSV-1-derived miR-H2-3p, miR-H3-3p, miR-H4-3p, miR-H4-5p, miR-H6-3p, miR-H27 and host-derived miR-21-5p, miR-146a-5p, miR-155-5p, and miR-138-5p and correlated with the oxidative stress chemokine IL-8 and the axonal damage marker neurofilament light chain (NfL). Replication-associated miR-H27 correlated with neuronal damage marker NfL, and cell-derived miR-155-5p correlated with oxidative stress marker IL-8. Elevated miR-138-5p targeting HSV-1 latency-associated ICP0 inversely correlated with lower HSV-1 antibodies in CSF. In summary, miR-H27 and miR-155-5p may constitute neuroinflammatory markers for delineating frequent and fluctuating HSV-1 replication and NfL-related axonal damage in addition to the oxidative stress cytokine IL-8 in the brain. Tentatively, HSV-1 remains a relevant pathogen conditioning autoimmune processes and a psychiatric clinical phenotype.
ADAM17 is a metalloprotease implicated in the proteolysis of angiotensin-converting enzyme 2 (ACE2), known to play a critical role in the entry and spread of SARS-CoV-2. In this context, ADAM17 results as a potential novel target for controlling SARS-CoV-2 infection. In this study, we investigated the impact on ACE2 surface expression and the antiviral efficacy against SARS-CoV-2 infection of the selective ADAM17 inhibitor JG26 and its dimeric (compound 1) and glycoconjugate (compound 2) derivatives using Calu-3 human lung cells. None of the compounds exhibited cytotoxic effects on Calu-3 cells up to a concentration of 25 µM. Treatment with JG26 resulted in partial inhibition of both ACE2 receptor shedding and SARS-CoV-2 infection, followed by compound 1. JG26, an ADAM17 inhibitor, demonstrated promising antiviral activity against SARS-CoV-2 infection, likely attributed to reduced sACE2 availability, thus limiting viral dissemination.