Search Results (135)

Porcine reproductive and respiratory syndrome virus (PRRSV) remains a major challenge to swine production worldwide. Current vaccines have limited efficacy against genetically diverse PRRSV strains. Therefore, strategies with alternative modes of action—such as antiviral approaches that target conserved virus–host interactions, including viral attachment and entry, rather than relying solely on adaptive immune responses—are needed. We first evaluated the in vitro effect of griffithsin (GRFT), a high-mannose-binding lectin, in the monkey kidney cell line MARC-145. Cells were pre-treated with GRFT (50–200 µg/mL) prior to PRRSV infection, after which cell morphology and viral RNA replication (measured by RT-qPCR) were assessed. Pre-treatment with 100–200 µg/mL GRFT, followed by PRRSV inoculation at a multiplicity of infection of 1 or 10, reduced viral replication in MARC145 cells in a dose-dependent manner, achieving almost 100% inhibition of ORF5 and ORF7 RNA compared with untreated controls (p < 0.0001). We next investigated the in vivo effects of intranasal GRFT administration (7.5 or 15 mg/day) in pigs (n = 56). Pigs treated with 15 mg/day GRFT exhibited significantly reduced (p < 0.05) viremia 2, 4 and 7 days post-challenge, compared with untreated, challenged, and controls (log₁₀ 8.1 ± 0.2 vs. 9.0 ± 0.25, 8.2 ± 0.1 vs. 9.1 ± 0.2, and 8.9 ± 0.2 vs. 9.3 ± 0.2, respectively), along with earlier resolution of fever and a trend toward increased average daily gain over 42 days (p < 0.1). These findings are the first report of GRFT efficacy in pigs and support its potential as an antiviral strategy against PRRSV, alongside existing interventions. Full article

Postoperative delirium (POD) is a frequent and serious complication among elderly surgical patients. Despite its clinical relevance, reliable biomarkers for early identification and pathophysiological insight remain limited. Recent evidence implicates systemic immune activation and complements dysregulation as contributors to cognitive decline after surgery. This study investigated the association between perioperative levels of selected complement pathway proteins and both the incidence and severity of POD. Methods: We performed a secondary analysis of 22 patients aged ≥ 60 years from the prospective CONFESS cohort undergoing elective spine surgery. Complement proteins (C1q, C2, C4), mannose-binding lectin (MBL), Factor D [FD], Factor B [FB], Factor I [FI] were quantified from blood samples collected at baseline, preoperatively, and on postoperative days 1 and 2. POD was assessed using the Nursing Delirium Screening Scale (Nu-DESC) and Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria. Delirium severity was rated with the Confusion Assessment Method–Severity (CAM-S) scale. Associations were tested using univariate and multivariate regression analyses. Preoperative levels of FD and C2 were significantly elevated in patients who developed POD (FD: p = 0.023; C2: p = 0.044), while C4 levels trended lower. FD remained an independent predictor of POD in multivariate regression (p = 0.049), although cognitive performance was the only significant predictor when adjusted for surgery duration. Delirium severity was associated with perioperative reductions in C1q, FI, and FB and with increased MBL levels, explaining up to 43% of CAM-S score variance. These findings highlight the role of complement activation—particularly FD, C2, MBL—in the development and clinical expression of POD. Complement profiling may offer a novel approach for risk stratification and therapeutic targeting in perioperative neurocognitive disorders. Full article

Background: Hepatitis B vaccination is the most effective strategy for preventing chronic hepatitis B virus (HBV) infection; however, interindividual variability in vaccine-induced antibody responses remains a significant challenge in the field. Innate immune components, particularly lectin complement pathway proteins such as mannose-binding lectin (MBL), mannose-associated serine protease 1 (MASP-1), and mannose-associated serine protease 2 (MASP-2), may contribute to this variability in outcomes. This study aimed to evaluate the association between serum MBL, MASP-1, and MASP-2 levels, birth weight, and humoral response to hepatitis B vaccination in infants. Methods: This single-center prospective observational study included 37 term infants who received hepatitis B vaccinations at birth, 1 month, and 6 months of age according to the national immunization schedule. Venous blood samples were collected at month 6, before, and month 7 after the 3rd vaccine dose. Serum MBL, MASP-1, MASP-2, and antiHB levels were measured using commercial ELISA and chemiluminescence assays. Data were analyzed using non-parametric statistical tests and Spearman’s correlation analysis. Results: AntiHB levels increased significantly following vaccination (median Pre-3rdVac: 125.8 mIU/mL; Post-3rdVac: 609.7 mIU/mL; p < 0.001). MASP-1 concentrations also showed a significant Post-3rdVac increase (median Pre-3rdVac: 809.52 ng/mL; Post-3rdVac: 1133.93 ng/mL; p = 0.019). Birth weight was positively correlated with both MASP-1 levels (r_s = 0.492, p = 0.004) and changes in MASP-1 concentrations (r_s = 0.524, p = 0.002) after the third dose. In addition, MASP-1 levels were positively associated with antiHB levels (r_s = 0.385, p = 0.030) and Post-3rdVac antiHB titers (r_s = 0.493, p = 0.004). In contrast, serum MBL and MASP-2 concentrations were not significantly associated with antiHB levels before or after vaccination. Conclusions: MASP-1, but not MBL or MASP-2, is associated with the magnitude of the antibody response to hepatitis B vaccination in infants. These findings suggest that specific components of the lectin pathway may influence vaccine-induced immunity, independent of MBL. Further large-scale studies incorporating genetic and functional analyses are warranted to clarify the mechanisms by which lectin pathway proteins shape hepatitis B vaccine response. Full article

Serum lectins in vertebrates play crucial roles in innate immunity as recognition molecules for pathogen-associated molecular patterns (PAMPs). In mammals, two major lectins, mannose-binding lectin (MBL) and ficolin, both containing N-terminal collagen-like domains, activate the lectin pathway of complement. While MBL and ficolin recognize distinct PAMPs, their counterparts in teleosts are less understood. To date, MBL and galactose-binding lectin (GalBL) have been identified in teleosts, but the presence of ficolin remains unclear. In this study, we purified a 31-kDa serum lectin from common carp that displayed carbohydrate-binding specificity similar to that of mammalian ficolin. Unexpectedly, this lectin lacked an N-terminal collagenous domain and showed the highest similarity to mammalian microfibril-associated glycoprotein 4 (MFAP4), suggesting that the lectin is distinct from fibulin. Biochemical analyses revealed that carp MFAP4-like lectin (MFAP4Lec) protein forms a hexamer in serum, specifically binds GlcNAc and GalNAc, and recognizes the fish pathogen Vibrio anguillarum. The binding was competitively inhibited by GlcNAc but not by EDTA, indicating Ca²⁺-independent recognition. These findings suggest that MFAP4Lec functions as a novel serum lectin in teleost fish, serving as a recognition molecule for bacterial pathogens in innate immunity. Full article

Diabetic nephropathy (DN) is a leading cause of end-stage renal disease (ESRD) globally. Beyond metabolic and haemodynamic stress, the complement system has emerged as a contributor to glomerular and tubulointerstitial injury. In type 1 diabetes mellitus (T1DM), complement proteins contribute through autoimmune mechanisms, while in type 2 diabetes mellitus (T2DM) they are linked to insulin resistance. In both, complement activation promotes micro- and macrovascular complications through inflammatory pathways that accelerate DN progression. This review summarises the current evidence on the role of complement activation in diabetic nephropathy (DN). First, we outline the mechanisms by which the complement system is activated through the lectin pathway (in which mannoses bind to modified glycosylation structures), the classical pathway (in which C1q recognises immune complexes/damaged self), and the alternative pathway (in which C3 ticks over and amplifies on damaged renal surfaces). Next, we consider the roles of their effector molecules (C3a, C5a, and C5b-9/MAC), and the consequences of regulatory dysfunction (e.g., CD59 dysfunction). When integrated with findings from renal histology, blood and urine biomarkers enable us to evaluate the correlation between prognosis, disease severity, and progression. We will also discuss therapeutic implications, including the rationale behind selective complement inhibition and future intervention strategies. Full article

Vaccine adjuvants play a crucial role in the field of vaccinology, yet they remain one of the least developed and poorly characterized components of modern biomedical research. The limited availability of clinically approved adjuvants highlights the urgent need for new molecules with well-defined mechanisms and improved safety profiles. Hemocyanins, large copper-containing metalloglycoproteins found in mollusks, represent a unique class of natural immunomodulators. Hemocyanins serve as carrier proteins that help generate antibodies against peptides and hapten molecules. They also function as non-specific protein-based adjuvants (PBAs) in both experimental human and veterinary vaccines. Their mannose-rich N-glycans allow for multivalent binding to innate immune receptors, including C-type lectin receptors (e.g., MR, DC-SIGN) and Toll-like receptor 4 (TLR4), thereby activating both MyD88- and TRIF-dependent signaling pathways. Hemocyanins consistently favor Th1-skewed immune responses, which is a key characteristic of their adjuvant potential. Remarkably, their conformational stability supports slow intracellular degradation and facilitates dual routing through MHC-II and MHC-I pathways, thereby enhancing both CD4+ and CD8+ T-cell responses. Several hemocyanins are currently being utilized in biomedical research, including Keyhole limpet hemocyanin (KLH) from Megathura crenulata, along with those from other gastropods such as Concholepas concholepas (CCH), Fissurella latimarginata (FLH), Rapana venosa (RvH), and Helix pomatia (HpH), all of which display strong immunomodulatory properties, making them promising candidates as adjuvants for next-generation vaccines against infectious diseases and therapeutic immunotherapies for cancer. However, their structural complexity has posed challenges for their recombinant production, thus limiting their availability from natural sources. This reliance introduces variability, scalability issues, and challenges related to regulatory compliance. Future research should focus on defining the hemocyanin immunopeptidome and isolating minimal peptides that retain their adjuvant activity. Harnessing advances in structural biology, immunology, and machine learning will be critical in transforming hemocyanins into safe, reproducible, and versatile immunomodulators. This review highlights recent progress in understanding how hemocyanins modulate mammalian immunity through their unique structural features and highlights their potential implications as potent PBAs for vaccine development and other biomedical applications. By addressing the urgent need for novel immunostimulatory platforms, hemocyanins could significantly advance vaccine design and immunotherapy approaches. Full article

Background: IgA vasculitis (IgAV) represents the most frequently seen form of vasculitis among children. Although it often resolves without intervention, renal involvement (IgAV nephritis) poses a risk for long-term complications. Although the lectin and alternative complement pathways are possible causes in its development, dependable serum biomarkers for the early identification of nephritis remain unavailable. Methods: In this prospective case-control study, we examined how the serum levels of a membrane attack complex (sC5b-9), complement factor H (CFH), mannose-binding lectin (MBL), and mannose-binding lectin-associated serine protease-1 (MASP-1) relate to renal involvement in IgAV. These complement proteins were measured in children diagnosed with IgAV and compared to levels in healthy controls (HCs) matched for age and sex. Results: The study cohort comprised 44 IgAV patients with a median age of 8 years and 34 HCs. The CFH levels were reduced significantly in the patient group (median: 357.31 ng/mL; IQR: 228.32) relative to the controls (median: 543.08 ng/mL; IQR: 504.05) (p < 0.001). This decrease was observed irrespective of the presence of nephritis. There were no significant differences in serum sC5b-9, MBL, or MASP-1 levels between the patients and controls. Furthermore, no correlation emerged between these complement components and renal involvement. Conclusion: The data suggest that lower CFH levels may signal systemic dysregulation of the alternative pathway in IgAV. In contrast, the serum levels of sC5b-9, MBL, and MASP-1 appear inadequate as markers for predicting renal involvement. Further research with larger cohorts that includes genetic analyses and examination of kidney tissue is needed to better define the contribution of complement activation in IgAV-related nephritis. Full article

Multivalent lectin–glycan interactions (MLGIs) are vital for viral infection, cell-cell communication and regulation of immune responses. Their structural and biophysical data are thus important, not only for providing insights into their underlying mechanisms but also for designing potent glycoconjugate therapeutics against target MLGIs. However, such information remains to be limited for some important MLGIs, significantly restricting the research progress. We have recently demonstrated that functional nanoparticles, including ∼4 nm quantum dots and varying sized gold nanoparticles (GNPs), densely glycosylated with various natural mono- and oligo- saccharides, are powerful biophysical probes for MLGIs. Using two important viral receptors, DC-SIGN and DC-SIGNR (together denoted as DC-SIGN/R hereafter), as model multimeric lectins, we have shown that α-mannose and α-manno-α-1,2-biose (abbreviated as Man and DiMan, respectively) coated GNPs not only can provide sensitive measurement of MLGI affinities but also reveal critical structural information (e.g., binding site orientation and mode) which are important for MLGI targeting. In this study, we produced mannuronic acid (ManA) coated GNPs (GNP-ManA) of two different sizes to probe the effect of glycan modification on their MLGI affinity and antiviral property. Using our recently developed GNP fluorescence quenching assay, we find that GNP-ManA binds effectively to both DC-SIGN/R and increasing the size of GNP significantly enhances their MLGI affinity. Consistent with this, increasing the GNP size also significantly enhances their ability to block DC-SIGN/R-augmented virus entry into host cells. Particularly, ManA coated 13 nm GNP potently block Ebola virus glycoprotein-driven entry into DC-SIGN/R-expressing cells with sub-nM levels of EC₅₀. Our findings suggest that GNP-ManA probes can act as a useful tool to quantify the characteristics of MLGIs, where increasing the GNP scaffold size substantially enhances their MLGI affinity and antiviral potency. Full article

Factor VIII (FVIII) interacts with Endoplasmic Reticulum (ER) chaperones Calnexin (CANX) and Calreticulin (CALR) and with ER-Golgi Intermediate Compartment (ERGIC) transporters, Lectin, mannose-binding 1 (LMAN1) and Multiple Coagulation Deficiency 2 (MCFD2). We previously reported that the Gamma-aminobutyric Acid Receptor-associated proteins (GABARAPs) also influence FVIII secretion. Here, we further investigated the intracellular dynamics of FVIII using single and double CRISPR/Cas9 Knockout (KO) models of the abovementioned chaperones as well as the GABARAP proteins in HEK293 cells expressing FVIII. Cellular pathways were manipulated by Brefeldin A (BFA), Chloroquine (CQ), a Rab7 inhibitor, and subjected to glucose starvation. The effect of each KO on FVIII secretion and organelle distribution was assessed by a two-stage chromogenic assay and immunofluorescence (IF) microscopy, prior and upon cell treatments. Using these approaches, we first observed distinct effects of each studied protein on FVIII trafficking. Notably, intracellular localization patterns revealed clustering of FVIII phenotypes in GABARAP^KO, CANX^KO, and CALR^KO cells together under both basal and treated conditions, an observation that was also reflected in their respective double KO combinations. Besides, a clear involvement of additional components of the endomembrane system was evident, specifically at the trans-Golgi space, as marked by FVIII colocalization with the Ras-like proteins in brain (Rab8 and Rab7) and with the Vesicle-Associated Membrane Protein (VAMP8), along with the observed impact of the selected cell treatments on FVIII phenotypes. These outcomes enhance our understanding of the molecular mechanisms regulating FVIII and pave the way for new perspectives, which could be further projected into FVIII replacement, cell and gene therapies. Full article

Recurrent vulvovaginal candidosis (RVVC), defined as three or more episodes of vulvovaginal candidosis (VVC) within a 12-month period, is a common and debilitating condition that affects a significant percentage of reproductive-aged women, negatively impacting their quality of life. This review aimed to synthesize the most recent scientific data on the pathophysiological mechanisms triggering primary or idiopathic RVVC. Three databases (PubMed, Scopus, and Web of Science) were searched for studies published between 2014 and 2024. Twelve studies were included, covering prospective cohort, cross-sectional, and case–control studies conducted in different countries. The results indicate that recurrence may be related to both intrinsic characteristics of the pathogen, such as increased virulence attributes of Candida spp., and host immune system dysregulation, including alterations in Th1/Th17 and Th2/Treg cytokine levels, decreased levels of mannose-binding lectin (MBL), impaired neutrophil and lymphocyte function, and overexpression of CD163+ macrophages and NLRP3 inflammasome. Additionally, genetic factors, such as polymorphisms in the MBL2, IL-12, NLRP3, and TLR2 genes, are associated with increased susceptibility to RVVC. In conclusion, RVVC appears to involve a complex interaction between pathogen virulence and an altered host immune response, which reinforces the need for further investigations to develop personalized therapeutic strategies. Full article

Alveolar Echinococcosis (AE) is a serious zoonotic disease caused by infection of Echinococcus multilocularis larvae. To survive within the host, E. multilocularis has developed a complex immune evasion mechanism including the inhibition of complement activation. This study focused on a calreticulin secreted by E. multilocularis (EmCRT) and its role in binding ability to human MBL and inhibiting MBL-mannose-mediated lectin pathway of complement activation. Results demonstrated the binding of recombinant EmCRT protein to both external and natural MBL in serum and the subsequent inhibition of MBL-mannose-initiated lectin pathway reflected by the reduced formation of complement intermediate products C3b and C4b. Fragment mapping determined that the MBL binding site was located within the S-domain of EmCRT. Combining with its role in inhibiting C1q-initiated classical complement activation in our previous study, the inhibition of MBL-mannose-initiated lectin pathway identified in this study suggests EmCRT plays an important role in the immune evasion of E. multilocularis alveolar larvae against host complement attack as a survival strategy within human tissue. This study supports the approach of using EmCRT as a good candidate for vaccine and drug development against E. multilocularis infection. Full article

Background: The global burden of inflammatory bowel diseases (IBDs), including ulcerative colitis and Crohn’s disease, is constantly rising. As IBDs significantly reduce patients’ quality of life, prevention and efficient treatment of IBDs are of paramount importance. Although the molecular mechanisms underlying IBD pathogenesis are still not completely understood, numerous studies indicate the essential role of oxidative stress in the progression of the diseases. Objective: The aim of this study was to investigate whether prophylactic administration of recombinant banana lectin (rBanLec) could positively affect antioxidative mechanisms in the colon and thus prevent or alleviate the severity of experimental colitis induced in C57BL/6 mice. Methods: The prophylactic potential of rBanLec, a mannose-binding lectin with immunomodulatory properties, was investigated in a model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in C57BL/6 mice. Mice received rBanLec at various doses (0.1, 1 and 10 μg/mL) before the induction of colitis. The severity of the disease was assessed by weight loss and reduction in colon length, and correlated with histopathological findings, cytokine milieu, and oxidative stress markers in the colon. Results: The obtained results revealed that pretreatment with a low dose of rBanLec (0.1 μg/mL) significantly reduced the severity of TNBS-induced colitis, as indicated by reduced weight loss, less severe histopathological damage, and a favorable anti-inflammatory cytokine milieu (increased IL-10 and TGFβ). In addition, rBanLec pretreatment improved the activity of antioxidant enzymes (SOD, CAT, and GST) and reduced markers of oxidative stress such as nitric oxide levels at the peak of the disease. In contrast, higher doses of rBanLec exacerbated inflammatory responses. Conclusions: Our findings indicate that at low doses rBanLec can alleviate the severity of colitis by modulating oxidative stress and promoting anti-inflammatory cytokine responses, positioning rBanLec as a potential candidate for treating IBDs. Full article

Algal lectin Griffithsin (GRFT) is a well-known mannose-binding protein which has broad-spectrum antiviral activity against several important infectious viruses including HIV, HCV, and SARS-CoV-2. Therefore, GRFT has been brought great attention to antiviral therapeutic development. In this report, we have tested GRFT’s activity against the lethal Ebola virus in vitro and in vivo. Our data have shown that the IC₅₀ value is about 42 nM for inhibiting Zaire Ebola virus (EBOV) infection in vitro. The preliminary in vivo mice model using mouse-adapted EBOV has also shown a certain efficacy for delayed mortality compared to the control animals. A GRFT pull-down experiment using viral particles demonstrates that GRFT can bind to N-glycans of EBOV. Thus, it can be concluded that GRFT, through binding to viral glycans, may block Ebola virus infection and has potential for the treatment of Ebola virus disease (EVD). Full article

Mannose-specific lectins are carbohydrate-binding proteins known for their antiviral potential. This study uses a bioinformatic approach to investigate the possibility of lectins from Allium sativum (garlic) and Allium ursinum (wild garlic) as inhibitors of SARS-CoV-2 entry. The information spectrum method (ISM) identified key interaction frequencies between the SARS-CoV-2 spike protein and these lectins, explicitly targeting the receptor-binding domain (RBD) and glycosylated asparagine residues, including N234. Lectins from Allium species showed a high affinity for oligomannose-type glycans on the spike protein, potentially blocking virus entry by preventing the spike-ACE2 receptor interaction. We propose that Allium lectins are promising candidates for further experimental validation as SARS-CoV-2 inhibitors, offering potential therapeutic applications in managing viral infections. Full article

A quarter of a century ago, sickle cell disease (SCD) was mainly viewed as a typical genetic disease inherited as a classical Mendelian trait. Therefore, the main focus concerning SCD was on diagnosis, meaning, genotyping, and identification of homozygous and heterozygous individuals carrying the relevant HbS mutant allele. Nowadays, it is well established that sickle cell disease is indeed the result of homozygosis for the HbS variant, although this single feature is not capable of explaining the highly diverse clinical presentation of SCD. In fact, an important feature of SCD is the chronic inflammation that accompanies the sickling of erythrocytes. In this manuscript, we will revisit the early evidence of inflammation in SCD and review what was uncovered during the last 25 years. Here, we describe Sickle cell anemia as a major participant in the history of science. In fact, SCD was the first genetic disease where the causal mutation was identified and is also the first disease for which treatment through genome editing was approved, making this disease a landmark in the road of molecular biology. Full article