Abstract:

Bacteriophages, traditionally viewed solely as antibacterial agents, are increasingly being studied for their immunomodulatory properties. In this study, we demonstrate that PM16 phage therapy not only effectively controls subcutaneous Proteus mirabilis infection in mice, but also induces long-term specific humoral immunity against subsequent reinfection. This immunomodulatory effect was dose-dependent. In vitro, PM16 directly activates macrophages, leading to increased production of proinflammatory cytokines (tumor necrosis factor-α and interleukin-1β) and inducible nitric oxide synthase, and enhances macrophage bactericidal activity against P. mirabilis. We assume that the enhancement of the adaptive immune response is mediated not by the phage acting as a classical antigenic adjuvant, but by its ability to prime innate immune cells, specifically macrophages. This priming leads to more efficient bacterial clearance, antigen presentation, and the formation of protective immunological memory.

Abstract:

Influenza A virus (IAV) vectors with truncated NS1 proteins combine strong innate adjuvanticity with genetic flexibility and are attractive platforms for immune modulation. We engineered an NS1-truncated A/Puerto Rico/8/34 (H1N1) virus, PR8/NS124_SS_CXCL10, to express human CXCL10 from the NS segment and compared its biological and immunological properties with the parental NS124 vector in mice. The CXCL10-expressing virus replicated efficiently in embryonated chicken eggs and MDCK cells and secreted high levels of CXCL10, but showed profoundly reduced replication in mouse lungs and peritoneal cavity, indicating a strongly attenuated in vivo phenotype. After intraperitoneal immunization, both vectors induced rapid local cytokine and innate-cell recruitment, although early inflammatory responses and viral RNA loads were lower with PR8/NS124_SS_CXCL10 than with NS124. Despite this attenuation, PR8/NS124_SS_CXCL10 elicited significantly higher frequencies of systemic antigen-specific CD8⁺ and CD4⁺ effector-memory T cells producing IFN-γ, TNF-α, and IL-2, and promoted robust recall CD8⁺ and CD4⁺ T-cell responses in the lungs following low-dose homologous challenge. In a stringent heterologous challenge model with A/Aichi/2/68 (H3N2), however, mice primed intranasally with the CXCL10 vector experienced greater weight loss than NS124-primed animals, consistent with enhanced T-cell–driven immunopathology in the context of insufficient early viral control. These data show that CXCL10 expression in an NS1-attenuated IAV backbone simultaneously enforces replication restriction and amplifies T-cell immunogenicity, supporting its potential as a chemokine-armed platform for immune modulation and oncolytic virotherapy while underscoring the need to carefully balance mucosal priming and recall in chemokine-expressing influenza vaccines.

Abstract:

Coagulase-negative staphylococci, including Staphylococcus capitis and Staphylococcus caprae can be causative agents of various nosocomial infections. A novel Staphylococcus phage StaphC_127, active against both S. caprae and S. capitis, was isolated from the surface of a spoiled tomato. All susceptible Staphylococcus strains were isolated from clinical samples collected from the irritated skin surface. StaphC_127 has low lytic activity against the host strain S. caprae CEMTC 1849 and is possibly a temperate phage as its genome encodes the repressor, antirepressor, and site-specific DNA recombinase. In addition, the StaphC_127 genome was detected in bacteriophage insensitive mutants (BIMs) obtained from at least two sensitive S. caprae strains after StaphC_127 infection. Notably, the StaphC_127 genome encodes the Tad2 protein belonging to the Tad2 phage protein family, which inhibits the Thoeris antiphage defense system. The obtained results of the genome analysis indicated that StaphC_127 is the first member of a new supposed Staphcevirus genus that, in turn, is part of a putative Estebevirinae subfamily containing phages capable of infecting coagulase-negative staphylococci.

Abstract: Schistosomiasis is a neglected tropical disease caused by parasitic trematodes of the genus Schistosoma, affecting millions of people globally. It poses a substantial public health challenge, particularly in low- and middle-income countries, most of which are in sub-Saharan Africa, where defaecating and urinating in or near freshwater bodies is prevalent. Despite decades of control efforts, including mass drug administration, reinfection by the parasites remains a common occurrence, with a vaccine being viewed as a crucial tool for sustainable control and ultimate elimination of the disease. Recent advancements in vaccine developments, particularly through the Vaccine Against Schistosomiasis in Africa initiative, therefore, offer hope of getting an anti-schistosomiasis vaccine soon. Several vaccine candidates, including Glutathione S-transferase, Sm-TSP-2, Sm14, and Sm-p80, are thus being explored currently, with Sm-p80, S. mansoni calcium-activated neutral protease, calpain, involved in tegmental maintenance, promising safety and immunogenicity results in Phase 1b trials conducted in a couple of African countries that pave the way for Phase 2a trials. These efforts, supported by global regulatory engagement and partnerships, aim to streamline the approval of the anti-schistosomiasis vaccine and ensure equitable access, but are not without challenges. This review, therefore, explores the current state of schistosomiasis vaccine development, highlighting key scientific, regulatory, and logistical gains made toward a viable and impactful vaccine solution against the disease.

Abstract: Background/Objectives: Yersinia pestis caused the three plague pandemics that claimed more than two hundred million human lives. There is still no vaccine that meets all WHO requirements, and many researchers continue to develop plague vaccines using various technological platforms. For example, researchers led by Roy Curtiss 3rd have developed a new approach to achieve controlled, delayed attenuation of bacterial pathogens. Mutants generated using this method were superior in protecting Y. pestis-infected mice immunized with strains generated using traditional gene knockout. However, further studies are needed to determine the safety and efficacy of these delayed-attenuated strains in other mammalian species in order to extrapolate on humans the data obtained in accordance with the FDA Animal Rule. In this study, we compared the role of delayed shutting down of the crp gene alone versus delayed silencing of the crp gene in combination with loss of the pPst plasmid or single crp knockout in the safety of mutants in mice and guinea pigs, as well as their ability to induce protective immunity in these two animal species. Methods: Three Y. pestis strains, a Δcrp mutant, a mutant with arabinose-dependent regulated crp expression (araC P_BAD crp) or araC P_BAD crp mutant cured of plasmid pPst, were derived from virulent wild-type strain 231. To evaluate the safety, outbred mice or guinea pigs were immunized subcutaneously with serial tenfold dilutions of mutated strains. For vaccine studies, immunized animals were subcutaneously challenged with 200 LD₁₀₀ of the wild-type Y. pestis strain. Results: The challenge caused the death of 100% of naïve animals in controls. The Y. pestis strain 231Δcrp was nonlethal in mice at a dose of 107 CFU. The LD₅₀ of 231Δcrp strain in guinea pigs increased at least by 107-fold compared to that of the wild-type strain. The LD50s of the 231P_BAD-crp mutant in mice and guinea pigs were approximately 104-fold and 107-fold higher than those of Y. pestis 231, respectively. The 231P_BAD-crp(pPst¯) strain did not cause death in mice (LD₅₀>10⁷ CFU) and guinea pigs (LD₅₀>10⁹ CFU) when administered subcutaneously and was capable of inducing intense protective immunity in both species of laboratory animals. Conclusions: Our research has shown once again the necessity of balance between safety and effectiveness demonstrating the feasibility of further investigation of crp mutants as promising candidate plague vaccines.

Abstract:

Biofilm-forming phytopathogens pose significant threats to global agriculture by causing persistent diseases in crops, leading to substantial economic losses and challenges in disease management. This review article aims to explore the mechanisms underlying biofilm formation by phytopathogens, with a particular focus on the role of the bacterial Type III secretion system (T3SS) in facilitating biofilm development and pathogenicity. Biofilms, which are structured communities of microorganisms encased in a self-produced matrix, enhance the survival and virulence of pathogens, making them resistant to conventional control methods. The article delves into the impacts of biofilm-associated infections on crop health, including weakened plant immunity and reduced yield. It also highlights the challenges faced by the agricultural industry, such as the limited efficacy of chemical treatments and the emergence of resistant strains. Innovative solutions, including biocontrol agents, quorum sensing inhibitors, nanotechnology-based approaches and edible coatings, are discussed as promising strategies to combat biofilm-related diseases. There is a need for a deeper understanding of biofilm dynamics, the development of sustainable management practices, and the integration of advanced technologies to mitigate the impact of biofilm-forming phytopathogens on agriculture.

Abstract:

Basal stem rot (BSR), caused by Ganoderma boninense, is a major threat to oil palm plantations, leading to severe yield losses and significant economic impact. Early detection of BSR remains challenging because of the delayed onset of symptoms, while monoculture practices further exacerbate disease prevalence. G. boninense, a white rot fungus, invades root and vascular tissues of oil palm, impairing water and nutrient transport, ultimately causing plant decay and death. This study aimed to isolate, characterize, and identify bacterial isolates with both anti-Ganoderma and plant growth-promoting (PGP) abilities from a commercial biofertilizer, CRPO, specifically formulated for oil palm cultivations. Two isolates, K3 (Margalitia shackletonii) and K8 (Bacillus subtilis) displayed strong antagonistic activity against G. boninense, with percentage inhibition of radial growth (PIRG) values exceeding 89%. For PGP traits, K3 demonstrated broad potential, including phosphate and potassium solubilization, nitrogen fixation, 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, siderophore and high indole-3-acetic acid production. In contrast, K8 displayed positive results only for nitrogen fixation and ACC deaminase production. The dual functions of these isolates in suppressing G. boninense while enhancing plant growth confirms their presence as biocontrol agents. These advance sustainable BSR management strategies by reducing reliance on chemical inputs and strengthening oil palm resilience.

Abstract: Staphylococcus aureus is an important microorganism that has the ability to form biofilm on a various range of surfaces. Factors contributing to the reduction of the effectiveness of the treatment are the development of resistance to antimicrobial drugs. Essential oils (EO) are effective and economical alternatives, however with the disadvantage of rapid oxidation, nanoencapsulation is an alternative that improves stability, reduces toxicity and controls the release of oil. Nanoprecipitation with Poly-lactide was used to obtain nanoparticles (NP) with EO. The antibiofilm effect was observed by the broth microdilution method. A cytotoxic assay was performed using a VERO cell line. Nanoparticles were found to be nanometric, round with regular structures. EO and NP show antibacterial and antibiofilm activity against S. aureus. NP was less cytotoxic than EO.aure Nanoparticle prevented rapid EO evaporation and degradation and enhanced its stability. NP stability was studied using zeta potential. Its value was determined to be around -23.1 mV, which indicates that NP are in fact stable. Melting temperature and melting enthalpy for Blank NP were 54.29 °C and 429.63 J/g. The decreasing in melting enthalpy from 429.63 to 115.83 J/g in NP containing EO makes this system favorable to controlled release of essential oils. NP has a smaller area under the peak, indicating that the EO may modify the crystalline organization, facilitating melting and thus the release of EO. EO and NP presented a growth inhibition of planktonic and biofilm formation against S. aureus. NP were less cytotoxic than free EO. Thus, these findings may contribute to the development of new strategies against infections caused by S. aureus.

Abstract: The oral cavity contains several microbial niches, including saliva, dental plaque and tongue coating, each shaped by distinct local environments and host factors. This study compared the ecological and functional characteristics of the microbiomes of these three oral sites within the same individuals and examined host conditions associated with their variation. Saliva, supragingival plaque and tongue coating samples were collected simultaneously from 31 adults without clinical oral lesions. The bacterial 16S rRNA gene (V3–V4 region) was sequenced using the Illumina MiSeq platform, and analyses included α and β diversity, Mantel correlations, differential abundance tests, network analysis and functional prediction. The three sites displayed a clear ecological gradient. Saliva and tongue coating were taxonomically similar but were influenced by different host factors, whereas plaque maintained a distinct, biofilm-like structure with limited systemic influence. Functional divergence was most pronounced on the tongue coating despite its taxonomic similarity to saliva, whereas functional differences between saliva and plaque were modest despite larger taxonomic separation. These findings indicate that microbial composition and function vary independently across oral niches and support the need for multi-site sampling to more accurately characterize oral microbial ecology.

Abstract: Background/Objectives: Brucella is a major global One Health threat, causing an estimated 2.1 million human infections and substantial livestock losses annually, with no vaccine currently available for humans, underscoring the urgent need for a safe and effective vaccine. Methods: Employing a reverse vaccinology approach, a novel 175-mer multiepitope vaccine (Mvax) targeting Brucella FrpB was computationally designed in this study, incorporating two B-cell, two MHC class I (MHC-I), and three MHC class II (MHC-II) epitopes selected for their high predicted antigenicity, safety, and IFN-γ-inducing potential. To further enhance immune activation, human beta-defensin-3 was fused to the N-terminus as an adjuvant, followed by comprehensive in silico evaluation of the construct. Results: Population coverage analysis showed the selected epitopes provide 99.59% global coverage for MHC class combined, suggesting broad immunogenic potential. Mvax is predicted to be substantially more soluble (Protein-SOL score 0.808 vs. 0.275) with greater antigenicity (VaxiJen score 1.06 vs. 0.61) than native FrpB. Dissociation constant (Kd) analysis at 37ºC predicts stronger binding of Mvax to human TLR4/MD2 and TLR2/TLR6 receptors. Immune simulations (over 100 days and three years) indicate that a single dose of Mvax may elicit a strong Th1 response, generate durable T-cell memory lasting up to three years, and produce elevated IL-12, IFN-γ, and IL-2 levels, along with approximately ten-fold higher IgM responses compared with FrpB. Conclusions: In silico data from this study suggest that Mvax could serve as a safe and effective vaccine candidate for human brucellosis, with the potential to induce long lasting immune memory; however, experimental validation is still required.

Abstract:

Vaginal microbiome composition has been linked to risk of preterm birth (PTB), a persistent global health challenge. 16S rRNA microbial profiling has identified specific vaginal community state types (CSTs) that have been associated with PTB risk. Diagnostic profiling requires standardised pre-analytical protocols. We evaluated two storage methods and validated a curated, vagina-specific 16S rRNA gene database (VagDB) to enhance annotation. Paired Copan FLOQ swabs from 22 women at high PTB risk were processed for either (a) dry/immediate freezing or (b) Amies-stabilisation/refrigeration. Amplicon sequence variants were generated via 16S rRNA gene (V4) PCR and Illumina sequencing. We assessed diversity, composition, and community state type (CST) allocation. Amies-stabilised samples yielded significantly higher DNA (p = 0.003), but this did not alter species richness, evenness, or community structure. VagDB enhanced species-level resolution. PCoA showed robust clustering by participant and CST (p < 0.001), irrespective of storage; CST concordance exceeded 90%. Routinely collected vaginal swabs in stabilisation medium with an 8–72-hour refrigeration window yields reliable data, supporting the integration of vaginal microbiome profiling into clinical PTB risk assessment.

Abstract:

Objectives: Porphyromonas gingivalis (P. gingivalis), a key periodontal pathogen, has been linked to atherosclerosis development. The clinical failure of antibiotics to improve cardiovascular outcomes necessitates alternative explanations. This study examines how sub-minimal inhibitory concentrations (sub-MIC) of metronidazole affect the biogenesis and pathogenic potential of P. gingivalis extracellular vesicles (EVs) on human umbilical vein endothelial cells (HUVECs). Design: EVs were isolated from untreated (N-EVs) and sub-MIC metronidazole-treated (M-EVs) bacteria through ultracentrifugation. Characterization included TEM, nanoparticle tracking analysis, and Western blotting for virulence factors. HUVECs were evaluated using viability, migration, cell death assays, ROS detection, NF-κB activation imaging, and cytokine measurement. Results: Sub-MIC metronidazole increased EVs production by 2.3-fold and enriched M-EVs with virulence factors (lipid A LPS, Kgp, RgpA). M-EVs demonstrated significantly stronger cytotoxicity, causing greater impairment of HUVEC viability and migration, alongside increased cell death. Mechanistically, M-EVs induced elevated mitochondrial and cellular ROS, promoting NF-κB activation and enhancing secretion of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6). Conclusion: Sub-MIC metronidazole exacerbates endothelial injury by amplifying EV production and virulence factor loading in P. gingivalis, offering a mechanistic explanation for the limited cardiovascular benefits of antibiotic therapy in periodontitis patients.

Abstract: Background: S. aureus is a significant cause of morbidity and mortality worldwide. The organism is an opportunistic pathogen, colonising the nose and skin, and its ability to acquire antimicrobial resistance (AMR), most notably against methicillin (MRSA), has created a global health crisis. Studies from Egypt reveal a high prevalence of S. aureus in clinical specimens, with MRSA rates often exceeding 40% and reaching up to 68.5% in surgical site infections (SSIs). Objective: To design, produce, and assess the predicted immunogenicity and cross-protectivity of a Multi-Antigenic Subunit Vaccine (MASV-SA) targeting highly prevalent Staphylococcus aureus (S. aureus) strains, including Methicillin-Resistant S. aureus (MRSA), circulating in Primary Medical Centres (PMCs) in Egypt. Methods: The vaccine candidate will consist of four recombinant, purified antigens: Capsular Polysaccharide Type 5/8 conjugates (CP5/8), Iron Surface Determinant B (IsdB), Alpha-Toxin Toxoid (HlaTox), and Panton-Valentine Leukocidin Toxoid (PVLTox). These antigens will be expressed recombinantly using the high-yield Pichia pastoris system. In silico analysis of IsdB and toxoid sequences from N=50 geographically diverse Egyptian S. aureus isolates will confirm antigen conservation. Proposed laboratory assays will include ELISA for antibody titre, Opsonophagocytic Killing Assay (OPKA) for functional antibody activity, and Flow Cytometry for TH17 T-cell response in immunised murine models. Results: The MASV-SA is expected to induce significantly higher IgG antibody titers (geometric mean titer (GMT) >5,000) compared to placebo, leading to a ≥2-fold increase in OPKA activity against a panel of Egyptian MRSA isolates. The vaccine is predicted to skew the cellular response toward a protective TH17 phenotype, crucial for eliminating S. aureus colonisation. Conclusion: The localised production of a multi-antigenic subunit vaccine offers a highly targeted and feasible prophylactic strategy to reduce the burden of S. aureus carriage and subsequent invasive infections within Egyptian PMCs, addressing a critical regional public health need.

Abstract: Serum lectins in vertebrates play crucial roles in innate immunity as recognition mole-cules 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 teleost are less understood. To date, MBL and ga-lactose-binding lectin (GalBL) have been identified in teleost, 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. Unex-pectedly, this lectin lacked an N-terminal collagenous domain and showed highest similarity to mammalian microfibril-associated glycoprotein 4 (MFAP4). Biochemical analyses revealed that carp MFAP4-like 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 MFAP4 functions as a novel serum lectin in teleost fish, serving as a recognition molecule for bacterial pathogens in innate immunity.

Abstract:

Sporothrix schenckii is a thermodimorphic fungus and one of the main etiological agents of sporotrichosis, a globally distributed subcutaneous mycosis that primarily affects the skin, subcutaneous tissue, and lymphatic system. Historically regarded as the classical species within the Sporothrix pathogenic clade, S. schenckii remains a clinically relevant pathogen and an important biological model for studying fungal dimorphism, virulence, and host–pathogen interactions. Major virulence factors include melanin production, thermotolerance, hydrolytic enzymes, and adhesins, all of which contribute to its survival and dissemination within the host. Clinically, S. schenckii causes a broad spectrum of manifestations ranging from fixed and lymphocutaneous cutaneous forms to disseminated and extracutaneous infections, particularly in immunocompromised individuals. This species exhibits a cosmopolitan distribution with endemic foci in the Americas, Asia, and Africa, and can be transmitted through both sapronotic and zoonotic routes. Diagnosis relies on fungal isolation, molecular identification, and histopathological examination, whereas treatment mainly involves itraconazole, potassium iodide, and amphotericin B for severe cases. This review integrates current knowledge on the biology, virulence, immune response, epidemiology, and treatment of S. schenckii, providing an updated overview of its significance as a medically important fungal pathogen with global relevance.

Abstract: Nutritional immunity is a major facet of host defense, wherein the host immune system strategically limits pathogen access to critical nutrients, including iron, zinc, vitamins, lipids, and amino acids, to repress microbial proliferation and virulence. This review provides a comprehensive synthesis of the molecular mechanisms that power nutrient immunity, including metal homeostasis, transporter modulation, hormonal regulation, and direct antimicrobial actions. We examine nutrient-specific strategies employed by the host, from iron withholding mechanisms to vitamin deprivation and copper-mediated toxicity. We also explore how diverse pathogens, including extracellular, intracellular, and eukaryotic, adapt to these hostile nutritional landscapes through siderophore diversification, regulatory integration, and metabolic rewiring. Comparative genomic analyses reveal convergent evolution in nutrient acquisition systems, illuminating the dynamic arms race between host restriction and microbial evasion. Further, we discuss the translational potential of nutritional immunity, cutting across nutrient-based therapies, host-directed interventions, and emerging diagnostic biomarkers. Finally, we suggest future directions that synergize nutritional immunity with microbiome ecology, global malnutrition, and personalized medicine. By elucidating the interconnection between metabolism and immunity, this review highlights the therapeutic promise of starving the pathogen to save the host.

Abstract:

Phages show efficacy against multidrug-resistant Pseudomonas aeruginosa, but limited host ranges require combining them in cocktails. In this work, we characterized 25 P. aeruginosa phages, developed therapeutic cocktails active against diverse clinical isolates, and tested phage efficacy in a mouse incisional wound model. These phages represent seven genera, and genomic and phenotypic analyses indicate that 24/25 are lytic and suitable for phage therapy. Phage host ranges on a diversity panel of 156 P. aeruginosa strains that included 106 sequence types varied from 8% to 54%, and together the 24 lytic phages were active against 133 strains (85%). All of the phages reduced bacterial counts in biofilms. A cocktail of five lytic phages, WRAIR_PAM1, covered 56% of the strain panel, protected 100% of mice from lethal systemic infection (vs. 20% survival in the saline-treated group) and accelerated healing of infected wounds. An improved 5-phage cocktail, WRAIR_PAM2, was formulated by a rational design approach (using phages with broader host ranges, more complementing activity, relatively low resistance background, and compatibility in mixes). WRAIR_PAM2 covered 76% of highly diverse clinical isolates and demonstrated significant efficacy against topical and systemic P. aeruginosa infection, indicating that it is a promising therapeutic candidate.

Abstract: Background: High-risk (hr) human papillomaviruses (HPV) testing is immensely important in elucidating the molecular epidemiology of HPV infections, and has become an essential part of current clinical practice in the management of the precancerous lesions and cervi­cal cancer risks. Evaluation of HPV testing systems suitable for large-scale organised cervical screening programs is required. Very little is known about the diagnostic performance of the Cobas assays in resource-limited settings, particularly in Mozambique. We evaluated the concordance of the Cobas 4800 and Cobas 5800 assays with the Cobas 6800 assay for detecting high-risk HPV genotypes in clinician-collected cervical samples. Methodology: In Mozambique implementation of HPV cervical screening is underway on a regional basis; currently in Maputo, and using the Cobas 4800, Cobas 5800, and Cobas 6800 tests. A random subset of 124 samples from women older than 18 years attending organised cervical cancer screening and previously tested for hrHPV-DNA using the Cobas 4800 and Cobas 5800, were used for a subsequent analysis on Cobas 6800. Results: Our results showed a good-to-high overall concordance of the Cobas 4800 and Cobas 5800 tests with Cobas 6800 test, showing strong Cohen’s kappa values (95%, κ = 0.89, 95% CI: 0.80–0.98, for Cobas 4800 versus Cobas 6800; and 100%, κ = 1.00, 95% CI: 1.00–1.00 for Cobas 5800 versus Cobas 6800). Similar performance to detect HPV-16, HPV-18, and the 12 other hrHPV genotypes was observed. Conclusion: The global performance to detect the 14 hrHPV genotypes was not significantly different between the three Cobas assays, which supports their suitability for use in large centralised laboratories included within population-based cervical cancer screening programs in resource-limited settings.

Abstract: Hericium erinaceus is a medicinal mushroom valued for its neuroprotective, immunomodulatory, and antioxidant activities. While many extracts and bioactive compounds from both mycelium and fruit bodies have been characterized, the mechanisms driving their effects are not fully understood. Here, the transcriptomic and protein-level effects of H. erinaceus mycelium (HDLM) in human peripheral blood mononuclear cells (PBMCs) were investigated, along with antioxidant and iron chelating activity. A commercially available β-glucan-enriched H. erinaceus fruit body extract (FBE) was included in a subset of assays to compare immune-related outcomes between mycelial and fruit body constituents. HDLM activated a wide array of immune- and oxidative stress–related transcripts and pathways, exhibited significant antioxidant activity, and consistently reduced IL-1β, TNF-α, and IL-8 during LPS challenge while maintaining low basal cytokine expression, indicating targeted immunomodulatory activity. FBE almost doubled production of IL-1β when challenged by LPS, whereas HDLM significantly decreased production of this stress mediator. HDLM also demonstrated augmented iron chelating ability when compared to FBE. Depending on tissue source and preparation methods, different H. erinaceus materials may either potentiate or quench stress responses, highlighting the need for bioactivity and safety comparisons across H. erinaceus supplements.

Abstract:

Listeria monocytogenes (Lm) is a Gram-positive, facultative intracellular bacterium traditionally known as a foodborne pathogen but increasingly recognized as a promising vector for cancer immunotherapy. Its unique virulence factors—such as listeriolysin O (LLO), internalins, phospholipases, and ActA—enable robust activation of cell-mediated immunity, making Lm-based vaccines superior to conventional treatments and other bacterial vectors. This review discusses the mechanisms by which recombinant Lm induces antitumor responses, including antigen presentation via MHC I and II pathways, and outlines strategies to attenuate pathogenicity while preserving immunogenicity, such as gene deletions, partial restoration of PrfA, and killed-but-metabolically-active strains. Furthermore, we examine key clinical trials evaluating Lm-based vaccines in HPV-associated cancers, prostate cancer, and HER-2-positive malignancies, highlighting their safety, tolerability, and efficacy in improving survival outcomes. The versatility of Lm-based immunotherapies positions them as a novel and effective approach in oncology, with ongoing trials paving the way for future therapeutic applications.