Abstract: Antibody-dependent enhancement (ADE) is a paradoxical immunological phenomenon in which pre-existing antibodies facilitate viral entry into host cells rather than conferring protection. ADE has been extensively characterised in flaviviral systems, most notably dengue virus (DENV), and presents a significant challenge for vaccine development and antibody-based therapeutic design. In coronavirus infections, ADE operates through both classical Fc gamma receptor (FcγR)-mediated pathways and an intrinsic signalling mechanism involving inhibitory FcγRIIb-mediated suppression of the type I interferon (IFN-I) response. Of critical translational relevance is the proposed cooperative FcγR–angiotensin-converting enzyme 2 (ACE2) entry model for SARS-CoV-2, wherein virus–antibody immune complexes simultaneously engage ACE2 through the viral spike receptor-binding domain (RBD) and FcγRIIa through the antibody Fc region on the same macrophage surface. This cooperative dual-receptor engagement may stabilise virion attachment, augment endosomal uptake, and trigger downstream signalling cascades that suppress antiviral immunity, potentially contributing to severe COVID-19 immunopathology. Feline infectious peritonitis virus (FIPV) represents one of the most rigorously documented biological systems in which antibody-mediated macrophage infection directly determines systemic disease outcome, providing a critical comparative framework for understanding coronavirus ADE across species. This comprehensive review integrates current knowledge of FcγR biology, coronavirus cell entry mechanisms, intracellular signalling cascades, cytokine dysregulation, comparative veterinary immunopathology, and nano-engineered immunomodulatory platforms for ADE-safe vaccine development. We critically evaluate lipid nanoparticle mRNA vaccines, virus-like particles, and polymeric nanoparticle systems as rational strategies to elicit selective neutralising antibody responses while mitigating ADE risk. We also highlight key unresolved mechanistic questions and future research directions essential for the development of safer vaccines and therapeutics against both current and emerging coronaviruses in human and veterinary medicine.

Abstract: Background/Objectives: Our previous study demonstrated that while the third SARS-CoV-2 booster effectively enhanced immunity against the Delta subvariant, its protection declined over time. This study aimed to evaluate and compare the humoral and cellular immune responses, as well as reactogenicity, of the mRNA-1273 vaccine administered as a fourth booster in healthy Thai adults previously vaccinated with two doses of CoronaVac (CV) followed by a third dose of either AZD1222 (AZ) or BNT162b2 (BNT). Methods: Participants received a single 100-µg (0.5 mL) intramuscular dose of mRNA-1273. Blood samples were collected at baseline (D0), D14, D90, and D180 to assess anti-RBD IgG, surrogate virus neutralization test (sVNT) against Delta and Omicron variants, IFN-γ levels, and reactogenicity. Results: Both 2CV/AZ- and 2CV/BNT-primed groups exhibited comparable local and systemic reactogenicity. The fourth mRNA-1273 dose markedly increased Delta variant inhibition within 14 days in both groups and remained at high levels at Days 90 and 180. sVNT inhibition against Omicron rose similarly in both groups at Day 14, it declined sharply by Days 90 and 180, with the 2CV/AZ-primed group showing significantly lower levels than the 2CV/BNT-primed group. Baseline anti-RBD IgG levels were lower in the 2CV/AZ group (p = 0.003) but surpassed those of the 2CV/BNT group by Day 14, with no significant differences at later time points. IFN-γ responses followed a similar pattern to anti-RBD IgG. Conclusions: A heterologous fourth mRNA-1273 booster in both 2CV/AZ- and 2CV/BNT-primed groups effectively enhances B-cell and T-cell responses against SARS-CoV-2. However, emerging variants such as Omicron may still pose challenges.

Abstract: Background: Personalized mRNA neoantigen vaccines represent a transformative approach to cancer immunotherapy, with recent Phase IIb data demonstrating a 49% reduction in melanoma recurrence when combined with pembrolizumab. However, two fundamental limitations constrain their efficacy: (1) fewer than 2% of mRNA molecules delivered via lipid nanoparticles (LNPs) escape the endosomal compartment to reach the cytoplasm, and (2) immunosuppressive tumor microenvironments (TMEs) in “cold” tumors blunt vaccine-induced T-cell responses. Current approaches address these challenges separately.Hypothesis: We propose that hydroxychloroquine (HCQ), when structurally incorporated as the ionizable lipid component of the LNP delivery system rather than administered as a separate systemic drug, creates a dual-function nanoparticle that simultaneously: (a) enhances mRNA endosomal escape by modulating endosomal pH maturation kinetics; (b) repolarizes tumor-associated macrophages from M2 to M1 phenotype via lysosomal Ca2+/mucolipin-1/p38/NF-κB signaling; (c) inhibits tumor-protective autophagy; and (d) reduces LNP-induced inflammatory side effects, enabling repeated dosing required for neoantigen vaccine protocols.Supporting evidence: Two independent 2025 studies demonstrated that HCQ-derived ionizable lipids achieve spleen-tropic mRNA delivery with simultaneous M2→M1 macrophage repolarization and anti-inflammatory properties permitting repeated dosing. We integrate these findings with our AI-driven Tumor Vaccine Responsiveness Score (TVRS) framework, which analyzed 8,432 TCGA Pan-Cancer Atlas specimens across 20 cancer types and identified that tumors most resistant to standard mRNA vaccines (pancreatic TVRS=11.7, glioblastoma TVRS=15.3) are precisely those where autophagy-dependent immune evasion is most active — making them ideal candidates for HCQ-LNP.

Abstract: Multiple sclerosis (MS) remains a leading cause of neurological disability, primarily due to the limited efficacy of current disease-modifying therapies in arresting progressive neurodegeneration. While peripheral lymphocyte depletion effectively manages relapsing activity, it fails to address the compartmentalized, smoldering inflammation driven by interactions between adaptive and innate immune systems within the central nervous system (CNS). The CD40–CD40L costimulatory pathway has emerged as a central regulator of these immune interactions, positioning it as a unique therapeutic target capable of addressing the full spectrum of MS pathology. This review examines the multimodal effects of CD40L blockade across peripheral and CNS-resident cell populations. Preclinical and genetic models demonstrate that inhibiting this axis suppresses pathogenic T-cell and B-cell responses while modulating innate immune activation, including macrophages, microglia, and astrocytes, and disrupting pro-inflammatory glial crosstalk. Early clinical data from second-generation, non-thromboembolic CD40L inhibitors, such as frexalimab, demonstrate reductions in markers of neuroaxonal injury and inflammatory disease activity. By simultaneously modulating systemic lymphocyte responses and CNS-resident innate immune processes, CD40L blockade represents a promising strategy to address both relapsing disease activity and progressive disability accumulation, thereby overcoming key therapeutic barriers in multiple sclerosis.

Abstract: Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system that culminates in inflammation, neuronal degeneration and loss of nerve functioning. While there is no specific cause of MS, there are factors that can influence disease progression, in particular tobacco smoke exposure (smoking). Smoking has been shown to increase inflammation, disease activity, and disability progression – herein we aim to connect this to both early inflammation and late-stage neurodegeneration. We propose that smoking enhances immune cell aging (immunosenescence) and examine evidence showing that this induces immune cell phenotypes that mirror physiological aging, specifically the depletion of naïve T-cell pools and the expansion of terminally differentiated, senescent CD8+ populations. We also review literature that suggests potential mechanism(s), including oxidative stress, cholenergic signaling, and epigenetic remodeling. By integrating clinical and mechanistic studies, we provide a framework that suggests smoking-associated immune aging shifts the MS profile from acute relapses toward sustained, treatment-resistant disability – and that smoking cigarettes is an active driver of disease, not just an environmental risk factor.

Abstract:

Background: BCG vaccination at birth remains the cornerstone of neonatal tuberculosis (TB) protection in high-burden countries. However, BCG induces severe, potentially fatal disseminated infection (BCGosis) in infants with Severe Combined Immunodeficiency (SCID). Saudi Arabia's 2019 policy delay of BCG to six months of age—intended to reduce BCGitis in SCID—leaves the vast immunocompetent neonatal population unprotected against TB during their most vulnerable window. Hypothesis: We propose that prophylactic hydroxychloroquine (HCQ), administered concurrently with BCG at 28 days of life in high-risk neonates, can achieve triple efficacy: (1) TB protection through maintenance of early BCG immunization, (2) BCG-complication mitigation through HCQ’s containment mechanisms, and (3) extended safety window for SCID diagnosis prior to irreversible BCGosis. The biological rationale rests on three pillars: HCQ’s direct intraphagosomal antimycobacterial activity, its anti-inflammatory attenuation of BCGitis, and its established safety profile via transplacental maternal administration. Critically, it is BCG itself—not HCQ—that acts as the trained immunity inducer, epigenetically reprogramming innate immune cells (monocytes, NK cells, macrophages) via H3K4me3 and H3K27ac histone modifications to mount enhanced responses to subsequent mycobacterial challenge. Evidence Base: Bernatowska et al. (2022) demonstrated that BCGosis in SCID occurs exclusively in the NK⁻ phenotype, implicating IFN-γ deficiency as the decisive pathogenic mechanism. HCQ is documented to alkalinize the phagolysosomal compartment, directly impairing mycobacterial replication, and to exert anti-inflammatory effects via TNF-α and IL-1β suppression. BCG, by contrast, is the established trained immunity inducer—epigenetically reprogramming monocytes and NK cells via mTOR-dependent pathways. These distinct and complementary roles create a biologically coherent basis for a BCG + HCQ prophylactic adjunct strategy. Conclusion: The HCQ + BCG approach, if validated, offers a pragmatic, cost-effective intervention for countries combining high consanguinity rates with significant TB burden. We call for a prospective, randomized controlled pilot trial in high-risk neonatal populations to evaluate this triple-efficacy hypothesis before broader implementation.

Abstract: Approximately 10% of the general population reports a penicillin allergy, making it one of the most commonly documented drug allergies in clinical practice. Yet formal evaluation confirms true hypersensitivity in fewer than 10% of these cases. This gap has practical consequences. Patients who carry an inaccurate allergy label are more likely to receive broader-spectrum alternative antibiotics, with downstream effects on cost, adverse drug events, and antimicrobial resistance. Although primary care physicians are often the first to record these labels and the ones who face their consequences most often in daily prescribing, they have remained peripheral to most systematic de-labeling efforts. In this narrative review, we examine how antibiotic allergy labels arise, why they persist, and what they cost—clinically, economically, and from a stewardship perspective. We also discuss emerging approaches to reassessment in primary care, along with the possible role of digital health tools and patient education in improving the accuracy of allergy documentation.

Abstract: Oral squamous cell carcinoma (OSCC) remains associated with poor outcomes and functional impairment despite multimodal treatment, underscoring the need for effective and less invasive therapeutic strategies. Ephrin type-B receptor 4 (EPHB4) is frequently expressed on OSCC cells and represents a potential target for chimeric antigen receptor (CAR)-T cell therapy. In this study, we evaluated the antitumor activity of EPHB4-targeted CAR-T cells (131CAR) using in vitro cytotoxicity assays against the OSCC cell line HSC-4 and an orthotopic tongue patient-derived xenograft (PDX) model established from an OSCC tumor (OC-15) in NOD scid gamma (NSG) mice. Flow cytometry confirmed EPHB4 expression in HSC-4 cells (~90%) and OC-15-derived tumor cells (~68%). In vitro assays demonstrated effector-to-target ratio–dependent cytotoxicity of 131CAR against HSC-4 cells. In vivo, both intratumoral and intravenous administration of 131CAR significantly reduced tumor burden compared to control groups, with greater tumor reduction observed following intratumoral delivery. Immunohistochemistry revealed infiltration of human CD8⁺ cells and decreased tumor area in treated tumors, and digital pathology analysis corroborated the reduced tumor area. These findings indicate that EPHB4-targeted CAR-T cells exert antitumor activity in an orthotopic OSCC model and suggest that local administration may enhance therapeutic efficacy in anatomically relevant settings.

Abstract: While recent reviews have firmly established hidradenitis suppurativa (HS) as a systemic inflammatory disorder inextricably linked to metabolic comorbidities, the investigation of lifestyle determinants remains a fraction of the research effort compared to the pursuit of pharmaceuticals. Consequently, current clinical approaches may not fully leverage natural modulators of systemic environmental inflammatory influx, a potential driver of the disease. The central premise of this study posits that the compromise of follicular integrity is directly coupled to lifestyle-driven systemic inflammation exceeding a critical threshold. While previous studies have relied on statistical regression and probabilistic frameworks for HS, this study establishes a deterministic multi-compartment ordinary differential equation framework to simulate the longitudinal kinetics of systemic and local lesion inflammation. Represented in this framework is the first mathematical formalization of the 2025 European S2k guideline interventions, explicitly modeling the resistance kinetics of antibiotics, the immunogenic decay of biologics, and the tapering dynamics of corticosteroids to simulate their longitudinal efficacy in HS. Furthermore, we introduce an abstractified framework that applies the laws of mass balance and pharmacokinetics directly to the disease state and key biologically relevant parameters, rather than focusing on cell types, targets, and individual cytokines. In this HS PK model, the lesion is connected to the systemic inflammation and acts as an integrator and amplifier, recording transient systemic spikes as permanent structural debt through an effect of hysteresis that progressively decouples the lesion from the systemic driver. Simulation studies suggest biologic agents provide a buffering capacity that creates a therapeutic equilibrium, which differs from resolving the underlying inflammatory mass balance. When evaluated across a virtual cohort, this reveals distinct kinetic populations. We demonstrate that clinical rebound is mathematically governed by phase space topology, where the disease state acts as a stable natural equilibrium. Upon pharmaceutical cessation, the therapeutic equilibrium collapses, causing the system to shift rapidly back to the disease state, driven by the underlying inflammatory load. Consequently, a comparative rescue trial demonstrated that pharmacological escalation encounters a saturation ceiling. This suggests that sustainable remission in HS may require a transformation that shifts the equilibrium itself, redefining lifestyle modification from an adjuvant option to the fundamental variable required to treat HS effectively.

Abstract:

Insulin resistance is increasingly recognized as a disorder of immunometabolic integration rather than a purely metabolic defect. Although chronic low-grade inflammation is known to impair insulin signaling, the upstream dietary and mucosal drivers sustaining innate immune activation in susceptible individuals remain incompletely defined. Here, we propose an immunopathophysiological hypothesis linking digestion-resistant gliadin peptides particularly the canonical 33-mer fragment to systemic insulin resistance through a gut-initiated innate immune cascade coupled to sulfur and redox dysregulation. The 33-mer gliadin peptide resists gastrointestinal proteolysis, permitting prolonged luminal persistence and sustained epithelial interaction. Experimental evidence demonstrates that gliadin binds the epithelial chemokine receptor CXCR3, inducing zonulin release and transient modulation of tight junctions. This regulated increase in intestinal permeability facilitates enhanced mucosal access of dietary peptides and microbial ligands to innate immune cells. We propose that this co-exposure potentiates MyD88-dependent Toll-like receptor signaling, with IRAK4 functioning as a central signaling hub. IRAK4-driven activation of NF-κB and stress kinase pathways interferes with insulin signaling while simultaneously imposing a chronic oxidative and nitrosative burden. Sustained innate immune activation accelerates glutathione consumption and suppresses transsulfuration pathway capacity, resulting in functional sulfur depletion. This redox imbalance compromises protein disulfide isomerase activity and insulin disulfide bond formation, linking mucosal immune activation to impaired insulin structural integrity, reduced bioactivity, hyperinsulinemia, and systemic insulin resistance. As an upstream experimental intervention, Aspergillus niger–derived prolyl endopeptidase is proposed to degrade resistant gliadin peptides prior to epithelial engagement and innate immune amplification. This falsifiable framework supports biomarker-guided stratification and staged validation across luminal peptide degradation, epithelial barrier modulation, innate immune signaling, sulfur metabolism, and tissue-level insulin responsiveness.

Abstract: Background: Antinuclear antibodies (ANAs) are frequently detected in patients with rheumatoid arthritis (RA); however, their prognostic relevance in predicting treatment escalation remains uncertain. Identifying biomarkers associated with earlier transition to advanced therapies may improve individualized disease management. Objectives: To evaluate the association of ANA status and titer levels with clinical characteristics, treatment trajectories, and time to biologic therapy initiation in patients with RA. Methods: In this retrospective cohort study, 223 patients with RA were stratified ac-cording to ANA status (112 ANA-positive, 111 ANA-negative). Baseline demographic data, disease activity (DAS28), and serological markers (RF, anti-CCP) were analyzed. Time to biologic therapy initiation, defined from the date of RA diagnosis to first bio-logic or targeted synthetic DMARD use, was assessed using Kaplan–Meier survival analysis and Cox proportional hazards regression. Multivariate models adjusted for relevant clinical covariates. Within the ANA-positive group, exploratory analyses compared low–moderate (1:80–1:320) and high (>1:320) ANA titers. Results: Baseline demographic and clinical characteristics were comparable between groups (all p > 0.05). ANA-positive patients more frequently initiated biologic therapy (48.2% vs. 24.3%, p < 0.001) and underwent multiple biologic switches (29.5% vs. 16.2%, p = 0.028). In multivariate analysis, ANA positivity was independently associated with earlier bi-ologic initiation (adjusted HR 2.14; 95% CI 1.32–3.46; p = 0.002), whereas RF and an-ti-CCP status were not significant predictors. In exploratory subgroup analysis, high ANA titers (>1:320) were associated with a lower hazard of biologic initiation com-pared with low–moderate titers (HR 0.24; 95% CI 0.06–0.98; p = 0.048). Conclusions: ANA positivity was independently associated with earlier initiation of biologic therapy in RA, supporting its potential incremental prognostic value beyond traditional sero-logical markers. The observed non-linear association between ANA titers and treat-ment escalation warrants cautious interpretation and validation in prospective studies.

Abstract: Background/Objectives: Poorly soluble aluminium (Al) compounds have successfully been used for decades as adjuvants in vaccines enabling an effective immune response. Yet the safety of Al exposure from vaccines is consistently questioned, especially re-garding infants. Since toxicokinetic data of aluminium after vaccination in humans are not available, model-informed predictions are needed for risk assessment. Methods: Using a physiologically-based toxicokinetic model we predicted the Al ex-posure from i.m. injections of Al-adjuvanted vaccines for full-term neonates to 50-year-old adults following the recommended vaccination schedule in Germany 2025 in addition to the continuous oral background Al exposure from dietary intake. Results: During the first two years of life, moderate (max. 2 to 3-fold) but transient in-creases of Al concentrations in plasma and in the relevant target organs liver and bone due to vaccinations were predicted. Increase in brain Al content (4%) was minimal. Most importantly, in all tissues, maximum Al levels did not exceed normal levels ob-served in infants soon after birth or known from adults. In children and adults, the rise in Al concentrations in plasma and tissues due to single vaccinations was marginal. The calculated contribution of vaccinations to the Al body burden at age 50 was negli-gible. Conclusions: From a toxicokinetic perspective, the additional Al exposure in full-term infants, children and adults from vaccinations with Al-adjuvanted vaccines according to the current recommended schedules is considered safe. The model has proven a valuable tool for predictions of Al exposure from vaccinations.

Abstract: Background :Post-acute sequelae of COVID-19 (PASC) in children present persistent symptoms that impair quality of life. Vitamin D’s immunomodulatory and microbiome-modulating properties suggest its potential to alleviate PASC symptoms. This study evaluated the efficacy of Vitamin D3 supplementation in alleviating symptom severity and to explore associated immunological and microbiome alterations in children with PASC. Methods: In a double-blind randomized controlled clinical trial, 33 children with PASC were assigned to receive 2,000 IU/day of oral vitamin D (Group A, n=21) or placebo (Group B, n=12) for 6 months. Serum 25-hydroxyvitamin D [25(OH)D] levels, symptom severity (Children’s Somatic Symptom Inventory-24, CSSI-24), immune cytokines, and checkpoint proteins were assessed at baseline (M0) and 6 months (M6). Nasal and rectal microbiota were analyzed using 16S rRNA sequencing to evaluate composition and predict functional pathways. Results: Serum 25(OH)D increased significantly in Group A compared with Group B (p < 0.01). Group A demonstrated significant reductions in CSSI-24 scores (p < 0.05), with improvements in neuropsychiatric, respiratory and cardiovascular symptoms. Pro-inflammatory cytokines including IFN-γ (FDR = 0.01) and MIP-1α (FDR = 0.0004) decreased, while checkpoint proteins TIM-3 and HVEM increased (both FDR < 0.05). Nasal microbiota in Group A at M6 showed increased richness and enrichment of Sphingomonas, Paenibacillus, Ralstonia, and Sphingobium, with functional pathways related to xenobiotic metabolism altered after supplementation. Coprobacillus abundance in rectal samples positively correlated with 25(OH)D levels and negatively with IFN-γ (p = 0.02). Pooling participants from both time points across group A indicated that higher 25(OH)D levels were associated with lower symptom scores. Conclusions: Vitamin D3 supplementation improved symptom severity, modulated immune responses, and altered microbiota profiles in children with PASC. These findings support Vitamin D3 as a potential adjunctive therapy for pediatric PASC and highlight host–microbe–immune interactions as therapeutic targets.

Abstract: Inflammatory bowel disease (IBD) is triggered by genetic predisposition and chronic inflammation, with aberrant activation of the innate immune complex NLRP3 inflammasome playing a pivotal role in its pathogenesis. In this study, we investigated the effects of a hot water extract from the brown alga Endarachne binghamiae (EB-WE) on the inhibition of NLRP3 inflammasome activation, with a focus on its antioxidant properties, in various inflammation models. In bone marrow-derived macrophages (BMDMs), NLRP3 inflammasome activation was induced using LPS and ATP, and EB-WE pretreatment (100, 200 µg/mL) significantly reduced the secretion of IL-1β and IL-18. Confocal immunofluorescence analysis further confirmed that EB-WE suppressed the formation of the NLRP3-ASC/caspase-1 complex. Furthermore, the in vivo anti-IBD efficacy of EB-WE was assessed using a DSS-induced mouse model, in which colonic inflammation and NLRP3-mediated responses were prominent. Oral administration of EB-WE (2 or 5 mg/day) markedly ameliorated clinical symptoms, such as weight loss, diarrhea, and rectal bleeding, and significantly reduced the disease activity index (DAI). EB-WE also decreased serum pro-inflammatory cytokine levels and the expression of NLRP3 inflammasome-related molecules in colon tissue at both the gene and protein levels. In both BMDMs and the IBD mouse model, we further analyzed the upstream regulatory pathway involving NOX2 -iNOS. EB-WE efficiently inhibited the activation of the NOX-iNOS axis and NF-κB phosphorylation, thereby alleviating inflammasome activation associated with DSS-induced oxidative stress and neutrophil/macrophage infiltration. Collectively, these results demonstrate that EB-WE effectively suppresses the formation and activation of the NLRP3 inflammasome by modulating the NOX-iNOS axis and the NF-κB pathway, via antioxidant mechanisms. These findings suggest that EB-WE holds promise as a novel marine-derived natural therapeutic agent for the treatment of chronic inflammatory diseases.

Abstract: Arthritis in K/BxN mice is provoked by pathogenic autoantibodies to glucose-6-phosphate isomerase (G6PI), which is a ubiquitously expressed enzyme that is present in cells, in the circulation and on the articular cartilage. When G6PI autoantibodies (auto-Abs) deposit on the articular cartilage of K/BxN mice, arthritis ensues due to the activation of various components of the innate immune system. Recent studies have investigated the in vivo efficacy of recombinant fragment-crystallizable (Fc) protein-based therapeutics. Many of the recombinant Fc proteins that have been evaluated have shown to have a protective effect in mouse models of arthritis, such as the K/BxN serum transfer model. More recently, rFc-µTP-L309C, a recombinant human IgG1-Fc with an additional point mutation at position L309C fused to the human IgM tail-piece to form a hexamer, has been shown to ameliorate the arthritis in K/BxN mice. Additional studies have shown that rFc-µTP-L309C has multiple effects that work together to ameliorate the arthritis, including inhibition of neutrophil migration into the joint, inhibition of IL-1β production, downregulation of Th1 and Th17 cells and increases in T regulatory cells and IL-10. In this work, rFc-µTP-L309C was shown to effectively prevent arthritis in the K/BxN serum transfer model and significantly down-regulate inflammatory cytokines/chemokines and ameliorate the arthritis in the endogenous K/BxN model. This amelioration of the arthritis was mediated by a significant decrease in antibody levels. Interestingly, this effect seems to be independent from the neonatal Fc receptor (FcRn). rFc-µTP-L309C was shown to specifically inhibit G6PI autoantibody secretion from B-cells with a concomitant increase in TGFβ and decrease in B-cell activating factor (BAFF). These new findings suggests that rFc-µTP-L309C may provide a therapeutic benefit for any antibody-mediated autoimmune disease through its effects on B cells.

Abstract: Background: The next generation (serum-free) rabies vaccine has been under development progress and shown good safety and immunogenicity profiles. A reduced 4-dose vaccine schedule, replacing the previously recommended 5-dose schedule, has been recommended for postexposure prophylaxis (PEP) to prevent human rabies. Methods: A randomized, double-blind, active-controlled phase Ⅰ/Ⅲ clinical trial in participants aged 10-60 years was conducted to evaluate the immunogenicity and safety of Sinovac serum-free rabies vaccine using 4-dose and 5-dose immunization schedules, in comparison with a licensed rabies vaccine in a simulated PEP setting. In the first part (phase Ⅰ), participants received five doses of Sinovac rabies vaccine on days 0, 3, 7, 14, 28 (5-dose schedule; D0, 3, 7, 14, 28) to preliminarily evaluate the safety. In the second part (phase Ⅲ), participants were randomized to four groups in a 1:1:1:1 ratio to receive Sinovac rabies vaccine of two 4-dose schedules (on D0, 3, 7, 14 or D0, 3, 7, 28) and 5-dose schedule, as well as receive the licensed rabies vaccine of 5-dose schedule. Rabies virus neutralizing antibodies (RVNA) titers were tested on days 0, 14, 28, 42, as well as on 3 and 6 months after the last dose. Immune non-inferiority and persistency and safety through to 6 months after the last dose were assessed in the second part. Results: A total of 2040 healthy participants were enrolled, with 40 and 2000 participants in the first and second part, respectively. Non-inferiority of Sinovac rabies vaccine compared with the licensed rabies vaccine was demonstrated, with the 95% lower limit confidence intervals (LLCI) of seroconversion rate differences ≥−5% on D14 and D42 and the geometric mean concentration (GMC) ratio ≥0.67 on D14. In the susceptible participants with RVNA <0.5 IU/mL on D0, the seroconversion rates of all three groups received Sinovac rabies vaccine were 100% by D14, and RVNA of 100% and at least 97.5% participants sustained ≥0.5 IU/mL through 3 and 6 months after the last dose. The safety profiles were similar across all groups, with most adverse reactions in Grade 1. There was no vaccine related serious adverse events reported. Conclusions: Sinovac serum-free rabies vaccine, when administered under the 5-dose or reduced 4-dose schedules, was non-inferior to the licensed rabies vaccine of 5-dose schedule, with no safety concerns identified.

Abstract: Background: Anti–double-stranded DNA (anti-dsDNA) antibodies are a key serological marker for Systemic Lupus Erythematosus (SLE) and are commonly assessed in con-junction with antinuclear antibody (ANA) testing by indirect immunofluorescence (IIF) on HEp-2 cells. However, their detection is influenced both by the heterogeneity of auto-immune response and by the characteristics of the analytical methods employed, com-plicating the diagnostic interpretation. Methods: In this retrospective single-center study, 3,090 patients undergoing anti-dsDNA analysis were screened, and 138 positive indi-viduals, with anti-dsDNA levels ≥15 IU/mL by fluoroenzyme immunoassay (FEIA), were included in the study. A control group of 29 anti-dsDNA–negative patients was also analyzed. Anti-dsDNA–positive patients were stratified by antibody levels (low, mild, high), and results were correlated with HEp-2 IIF titers and fluorescence patterns. In a subset of 30 positive patients, the anti-dsDNA antibodies had also been evaluated using immunoblot (IB) and Crithidia Luciliae indirect Immunofluorescence Test (CLIFT). Sta-tistical analyses assessed associations and concordance among methods. Results: Higher anti-dsDNA levels were generally associated with higher Hep-2 IIF titers. However, a considerable percentage (35%) of patients with positive anti-dsDNA were negative by HEp-2 IIF. Notably, high anti-dsDNA levels were detected in 19% of Hep-2 IIF–negative patients (titer 1:320). In the subset of 30 positive patients, FEIA analysis showed high concordance with immunoblot in both IIF positive (81%) and negative (100%) patients while CLIFT demonstrated lower agreement with both FEIA and IB independently from the IIF. Conclusions: Our findings indicate that anti-dsDNA an-tibody detection may occur independently of HEp-2 IIF positivity and that FEIA, par-ticularly when confirmed by immunoblot, represents a reliable approach for anti-dsDNA assessment. The observed results in this study likely reflect differences in epitope recognition and assay sensitivity among methods, suggesting the use of a multi-step diagnostic strategy in the serological evaluation of SLE.

Abstract: Background: Collagen XIα1, encoded by the COL11A1 gene, is a minor fibrillar collagen that is overexpressed in various human cancers, in which its presence correlates with tumor aggressiveness and progression. Methods: In this study, we developed two novel mouse monoclonal antibodies (mAbs), Anti-colXIα1 clone 3 and Anti-colXIα1 clone 9, that target the putative C-telopeptide of human collagen XIα1. The antibodies were raised to the RRHTEGMQA sequence, a unique nine-amino acid stretch within the putative C-telopeptide of human collagen XIα1. Results: Corresponding to nearly identical V(D)J gene segments and complementarity-determining regions (CDRs), the antibodies specifically bound the RRHTEGMQA epitope in ELISAs but did not react with the C-propeptide. This specificity was further confirmed with the purified Anti-colXIα1 clone 9 mAb, which demonstrated strong reactivity to recombinant proteins containing the RRHTEGMQA sequence in both ELISAs and Western blot assays. This sequence seems to behave as a linear B-cell neoepitope, in which the RRHT motif is crucial for epitope recognition. Otherwise, no immunodetections were observed either in cultures and lysates from the COL11A1-highly expressing A204 human cell line or on tissue sections from specimens of human pancreatic ductal adenocarcinoma (PDAC), with strong desmoplastic reactions, Conclusions: Lacking a precise knowledge of the characteristics of the putative C-telopeptide of human collagen XIα1, these antibodies could enhance our understanding of the processing of human procollagen XIα1 and contribute to a better characterization of the tumor microenvironment of COL11A1-expressing cancers.

Abstract: Background: Eosinophilic esophagitis (EoE) pathophysiological mechanism is complex and it s still being investigated. We believe there is a group of patients with eosinophilic esophagitis which we could differentiate as having an allergic phenotype, who exhibit a sensitization profile (aeroallergens, panallergens, foods and specific IgG4 levels) with significant differences when compared to patients with conventional allergic disease without associated eosinophilic esophagitis and healthy controls. Method: We have measured the prevalence of sensitization to aeroallergens, foods and panallergens by means of molecular diagnostic techniques (ImmunoCAPTM ISAC) and determined the levels of specific IgG4 against foods and eosinophilic derived neurotoxin (EDN) (ImmunoCAP technology) in patients with EoE of allergic phenotype to study if there are statistically significant differences with respect to the control groups (patients with different allergic pathologies without EoE and healthy patients without documented allergies). The total number of patients under study was 118, distributed among the different study groups. The case group (Allergic phenotype EoE patients) has 48 subjects. The food and respiratory allergy control groups, 30 subjects each. Finally, we included 10 in the healthy control group. Results: We were able to identify statistically significant differences when comparing levels of food-specific IgG4. Milk, egg, wheat, nuts, soy, cod, and LTP stood out. We did not observe significant differences in relation to sensitization to aeroallergens, foods, or panallergens. We also did not observe differences in EDN levels. Conclusion: We present a study in which statistically significant differences in IgG4 levels were observed in response to different types of food, comparing patients with eosinophilic esophagitis of allergic phenotype (case group) against subjects with allergic pathology without EoE and healthy subjects (control groups). Determining whether the detected foods are clinically relevant or not in these patients would be fundamental to establishing their usefulness as a treatment alternative in our patients.

Abstract: Background: Killed Whole Cell Genome-Reduced Bacteria (KWC/GRB), a versatile vaccine platform, can produce very low cost, thermostable, easily manufactured vaccines expressing complex immunogens that include potent immunomodulators. This system supports iterative optimization through a Design–Build–Test–Learn (DBTL) workflow aimed at enhancing immunogenicity. We applied this approach to developing an HIV-1 gp41 Membrane-Proximal External Region (MPER) vaccine using the scaffolded MPER antigen, 3AGJ, a recombinant heterologous protein engineered to mimic MPER structures recognized by broadly neutralizing monoclonal antibodies (bNAbs). Methods: Five KWC/GRB vaccines expressing versions of 3AGJ were designed, including versions linked to immunomodulators and multimers of the immunogen. Display on the surface of the bacteria was evaluated by flow cytometry using the broadly neutralizing monoclonal antibody 2F5. Outbred HET3 mice were vaccinated intramuscularly, MPER-specific an-tibody responses were assessed by ELISA, and the ability of the vaccines to induce neutralizing antibodies determined. Neutralization was measured against tier 1 and tier 2 HIV-1 pseudoviruses. Results: All five vaccines were strongly expressed on the bacterial surface and induced clear MPER-specific antibody responses in every mouse. About 33% of the animals showed detectable HIV-1 neutralization. Conclusion: A KWC/GRB 3AGJ scaffold-MPER vaccine can induce HIV-1 neutralizing antibodies. While improvements in the responses would be needed for a clinically useful vaccine, the findings provide an initial validation of the concept. There are many strategies that can be used to enhance and extend immune responses induced by KWC/GRB vaccines that can be employed to yield improved anti-HIV immune responses.