Search Results (79)

Background: Sexually transmitted infections (STIs) remain a major global health concern, with over one million new curable cases reported daily and limited long-term treatment options. Additionally, there are limited treatment options for women with bacterial vaginosis (BV), a dysbiotic condition predisposing them to STIs. Computationally designed human-milk-inspired antimicrobial peptides (AMPs) are promising candidates for novel antiviral and antibacterial therapies. This study evaluated the cervicovaginal mucosal safety and antiviral activity of three human-milk-inspired AMPs (MAT-006, UCD-MAT-001, and UCD-MAT-002) previously shown to exhibit antimicrobial activity against BV-causing pathogens. Methods: AMP cytotoxicity and inflammatory responses were assessed in relevant genital tract cell lines and cervicovaginal tissues in vitro. AMP anti-HIV-1 and anti-HSV-2 activities were characterized in female genital tract cell lines, TZM-bl cells and HEC-1-A cells, respectively, and in time-of-addition (pre-, co-, and post-HIV-1 challenge; and post-HSV-2 challenge) experiments. The impact of seminal plasma on AMPs’ activity was also evaluated. Results: At the concentrations tested, all three AMPs showed minimal cytotoxicity and no pro-inflammatory responses in cellular and ectocervical tissue explant models. In both co- and post-exposure models, all three AMPs inhibited HIV-1 and HSV-2 replication with IC₅₀ values ranging from 0.78 to 7.72 mg/mL. MAT-006 further showed pre-exposure anti-HIV-1 activity after 6 h (IC₅₀ = 1.07 ± 0.515 mg/mL) and 24 h (IC₅₀ = 0.69 ± 0.152 mg/mL) of incubation. Seminal plasma did not significantly impair MAT-006 and UCD-MAT-001 antiviral activity under experimental conditions. Conclusions: These findings demonstrate the antiviral activity of human-milk-inspired AMPs against HIV-1 and HSV-2 at concentrations that are safe to the cervicovaginal mucosa in vitro, warranting further preclinical evaluation as microbicide candidates with dual antibacterial and antiviral properties. Full article

Exposure to ultraviolet (UV), particularly UVA radiation, is a primary driver of photoaging due to its deep dermal penetration, which triggers DNA damage, collagen degradation, and immune suppression. Chebulinic acid (CA), a polyphenolic compound from Terminalia chebula, exhibits potent antioxidant and anti-inflammatory properties against UVB-induced skin damage. However, its large molecular weight hinders transdermal delivery and the TAT_47–57 peptide (core of HIV-1 TAT) enables rapid transmembrane transport. Large particles with double-layer membrane structure and a diameter exceeding 1000 nm were obtained during the separation of plant-derived exosome-like nanoparticles (PELNs), which are not considered as PELNs (50–500 nm), after a mixture with TAT anchored to the surface of engineered artificial vesicles (EAVs) and extrusion causes membrane fusion, employed as novel nanocarriers to overcome the difficulty in skin penetration by leveraging their lipid bilayer structure and surface membrane-anchored TAT for efficient epidermal fusion and intercellular penetration. Furthermore, CA-loaded TAT-ePELNs demonstrate significant efficacy in mitigating UVA-induced photoaging. Collectively, this study expands the anti-UVR damage application spectrum of CA from UVB to UVA exposure and establishes a green, efficient, and biosafe strategy for transdermal drug delivery by utilization of non-PELNs generated during the preparation process of PELNs. Full article

This review describes a novel method for increasing the effectiveness of inactivated enveloped whole-virus vaccines by targeting them for extensive uptake by antigen-presenting cells (APCs). Several inactivated whole-virus vaccines with dense glycan shields display suboptimal effectiveness because the multiple carbohydrate chains (glycans) on the virus mask immunogenic peptides and surround the virus with a negative electrostatic charge that decreases uptake by APCs. It is postulated that engineering such vaccinating viruses to present the carbohydrate antigen “α-gal epitope” on the glycan shields will immunocomplex them with the anti-Gal antibody; thus, it will target them for robust uptake by APCs. Anti-Gal is an abundant natural antibody in humans, constituting ~1% of human circulating immunoglobulins. The ligand of anti-Gal is the α-gal epitope, which is naturally synthesized in non-primate mammals and New World monkeys by the glycosylation enzyme α1,3galactosyltransferase. This enzyme is encoded by the GGTA1-gene. Viral vaccines presenting multiple α-gal epitopes on their glycan shield bind anti-Gal and activate the complement system to produce complement chemotactic cleavage peptides C5a and C3a that induce extensive recruitment of APCs to vaccine injection sites. The virion-bound anti-Gal further targets the viral vaccine for robust uptake by APCs, following binding of its Fc “tail” to Fcγ-receptors on APCs. The efficacy of this method was studied in anti-Gal-producing mice with α-gal presenting inactivated influenza virus vaccine and with gp120 of HIV presenting this epitope. These studies indicated that virus vaccines engineered to present α-gal epitopes increase anti-virus antibody production and virus-specific T-cell activation by 15- to 100-fold in comparison to the same vaccines lacking α-gal epitopes. It is suggested that α-gal presenting inactivated SARS-CoV-2 virus vaccines can induce a similar protective long-term immune memory against S- M-, E-, and N-viral proteins. Furthermore, immune-escaping variants of the mutated S-protein may be destroyed by antibodies to M and E proteins, and cells infected with such variants may be killed by cytotoxic T cells specific to peptides of the N-protein. Such an anti-M-, E-, and N-protein immune protection may prevent expansion of these variants and thus may avoid the need for immunization with COVID-19 vaccines every 6 months or following the appearance of new variants. A similar potent immunization may be achieved with an inactivated Ebolavirus vaccine engineered to present α-gal epitopes on the glycan shield. The resulting immune response to the various Ebolavirus proteins also may contribute to cross-reactive protection against other Ebolavirus species containing proteins with evolutionarily conserved structures. An effective method for the preparation of a whole-virus vaccine presenting α-gal epitopes is by arming it with the GGTA1-gene inserted into the viral genome. Such virions will present multiple α-gal epitopes on their glycan shield, which will amplify their immunogenicity instead of reducing it in the wild-type virus. Full article

HP1090 is a short, cationic, amphipathic peptide derived from scorpion venom and previously described as a membrane-active antiviral compound. Here, we primarily characterize the antiviral activity of HP1090 and assess whether additional antibacterial effects are consistent with membrane-disruptive properties. Chemically synthesized HP1090 exhibited dose-dependent virucidal activity against multiple enveloped viruses, including herpes simplex virus type 1 and 2 (HSV-1, HSV-2), human immunodeficiency virus type 1 (HIV-1), and Zika virus (ZIKV), with IC₅₀ values ranging from 14.7 to 56.1 µg/mL. No activity was observed against the non-enveloped human rhinovirus 14 (HRV14), suggesting strict dependence on a viral lipid envelope. Consistent with a membrane-targeting mechanism, HP1090 induced rapid and concentration-dependent permeabilization of virus-like liposomes. HP1090 also displayed antibacterial activity against selected clinically relevant pathogens in agar-based growth inhibition assays. However, antibacterial effects required substantially higher concentrations (>125 µg/mL) and varied between bacterial species, with some strains showing little or no susceptibility. Membrane permeabilization assays in Listeria monocytogenes demonstrated disruption of bacterial membrane integrity as a contributing mechanism. No cytotoxicity was observed on mammalian cell lines at effective antiviral concentrations. Together, these findings establish HP1090 as a membrane-active venom peptide and, by linking envelope-dependent viral inactivation with bacterial membrane permeabilization, support a shared biophysical mode of action relevant to the development of membrane-targeting anti-infectives. Full article

Cytomegalovirus (CMV) seropositivity associates with cardiovascular disease in healthy adults, but associations are unclear in people living with HIV (PLWH) despite their high CMV burden. However, CMV antibody levels correlated with inflammatory biomarkers only in PLWH who subsequently developed coronary artery disease (CAD), so the effects of CMV in an individual may vary. Here we investigate the role of CMV-encoded interleukin-10 (cmvIL-10) in PLWH on anti-retroviral therapy. Plasma levels of cmvIL-10 and antibodies reactive with a cmvIL-10 peptide or a lysate of CMV-infected fibroblasts were assessed in PLWH with or without CAD. cmvIL-10 was assessed at diagnosis/selection (T0) and 12 months earlier (T-12), with anti-cmvIL-10 also assessed at −24 and −36 months (n = 36–58/group). Plasma cmvIL-10 was recorded as positive in 5–10 PLWH per group, irrespective of CAD status. Of 21 PLWH with detectable cmvIL-10, only six were positive at both timepoints. Anti-cmvIL-10 was measurable in all samples, at levels independent of cmvIL-10, CAD or time of sampling. Amongst PLWH without CAD, the detection of cmvIL-10 associated with higher levels of CXCL10 (T0 and T-12) and lower levels of the IL-1 receptor antagonist (IL-1Ra; T0 only). At T-12, anti-cmvIL-10 correlated with IL-1Ra in PLWH without CAD (p = 0.01), and sCD14 in PLWH with CAD (p = 0.01). Anti-cmvIL-10 correlated with VCAM-1 at several timepoints in both groups. Hence, cmvIL-10 may be produced episodically, inducing anti-cmvIL-10 peptide antibody, which may represent levels of the cytokine averaged over time. Plasma levels of cmvIL-10 and anti-cmvIL-10 antibody associated differently with inflammatory biomarkers in PLWH with and without CAD, suggesting mechanisms by which host responses to CMV may have different clinical consequences. Full article

Herpes simplex viruses (HSV-1 and HSV-2) are highly prevalent human pathogens that establish lifelong latency in sensory neurons, posing a persistent challenge to global public health. Their clinical manifestations range from mild, self-limiting orolabial lesions to severe, life-threatening conditions such as disseminated neonatal infections, focal encephalitis, and herpetic stromal keratitis, which can lead to irreversible corneal blindness. Beyond direct pathology, HSV-mediated genital ulcerative disease (GUD) significantly enhances mucosal susceptibility to HIV-1 and other sexually transmitted infections, amplifying co-infection risk and disease burden. Despite decades of clinical reliance on nucleoside analogues such as acyclovir, the therapeutic landscape has stagnated with rising antiviral resistance, toxicity associated with prolonged use, and the complete inability of current drugs to eliminate latency or prevent reactivation continue to undermine effective disease control. These persistent gaps underscore an urgent need for next-generation antivirals that operate through fundamentally new mechanisms. Marine ecosystems, the planet’s most chemically diverse environments, are providing an expanding repertoire of antiviral compounds with significant therapeutic promise. Recent discoveries reveal that marine-derived polysaccharides, sulfated glycans, peptides, alkaloids, and microbial metabolites exhibit remarkably potent and multi-targeted anti-HSV activities, disrupting viral attachment, fusion, replication, and egress, while also reshaping host antiviral immunity. Together, these agents showcase mechanisms and scaffolds entirely distinct from existing therapeutics. This review integrates emerging evidence on structural diversity, mechanistic breadth, and translational promise of marine natural products with anti-HSV activity. Collectively, these advances position marine-derived compounds as powerful, untapped scaffolds capable of reshaping the future of HSV therapeutics. Full article

Background/Objectives: New vaccine platforms that rapidly yield low-cost, easily manufactured vaccines are highly desired, yet current approaches lack key features. We developed the Killed Whole-Cell/Genome-Reduced Bacteria (KWC/GRB) platform, which uses a genome-reduced Gram-negative chassis to enhance antigen exposure and modularity via an autotransporter (AT) system. Integrated within a Design–Build–Test–Learn (DBTL) framework, KWC/GRB enables rapid iteration of engineered antigens and immunomodulatory elements. Here, we applied this platform to the HIV-1 fusion peptide (FP) and tested multiple antigen engineering strategies to enhance its immunogenicity. Methods: For a new vaccine, we synthesized DNA encoding the antigen together with selected immunomodulators and cloned the constructs into a plasmid. The plasmids were transformed into genome-reduced bacteria (GRB), which were grown, induced for antigen expression, and then inactivated to produce the vaccines. We tested multiple strategies to enhance antigen immunogenicity, including multimeric HIV-1 fusion peptide (FP) designs separated by different linkers and constructs incorporating immunomodulators such as TLR agonists, mucosal-immunity-promoting peptides, and a non-cognate T-cell agonist. Vaccines were selected based on structure prediction and confirmed surface expression by flow cytometry. Mice were vaccinated, and anti-FP antibody responses were measured by ELISA. Results: ELISA responses increased nearly one order of magnitude across design rounds, with the top-performing construct showing an ~8-fold improvement over the initial 1mer vaccine. Multimeric antigens separated by an α-helical linker were the most immunogenic. The non-cognate T-cell agonist increased responses context-dependently. Flow cytometry showed that increased anti-FP-mAb binding to GRB was associated with greater induction of antibody responses. Although anti-FP immune responses were greatly increased, the sera did not neutralize HIV. Conclusions: Although none of the constructs elicited detectable neutralizing activity, the combination of uniformly low AlphaFold pLDDT scores and the functional data suggests that the FP region may not adopt a stable native-like structure in this display context. Importantly, the results demonstrate that the KWC/GRB platform can generate highly immunogenic vaccines, and when applied to antigens with well-defined native tertiary structures, the approach should enable rapidly produced, high-response, very low-cost vaccines. Full article

Objective: The six-helix bundle (6-HB) is critical for HIV-1 membrane fusion. To disrupt this process, peptide inhibitors have been meticulously designed to target interactions within the 6-HB regions, thereby blocking membrane fusion and exerting inhibitory effects. Current peptide inhibitors like Enfuvirtide suffer from drug resistance and short in vivo half-life. This study aims to design novel anti-HIV-1 peptides by integrating heptad-repeat rules and membrane-anchor strategies. Methods: Artificial peptides were designed using HR rules from the HIV-1 gp41 6-HB motif and membrane-anchor modifications. Results: EK35S-Palm has emerged as a highly promising candidate for HIV-1 inhibition, exhibiting robust binding affinity to the target and effectively impeding the 6-HB spontaneous formation. Discussion: HR-based design avoids viral sequence homology, and membrane anchoring enhances local agent concentration, improving pharmacokinetics. The HR binding and membrane stabilization of EK35S-Palm provide synergistic inhibition. Conclusions: Integrating HR structural design with membrane-anchor strategies yields potent HIV-1 fusion inhibitors. EK35S-Palm demonstrates superior efficacy and stability over current therapies. These approaches hold great potential for overcoming the current therapy limitations and advancing the more effective and durable HIV-1 fusion inhibitors. Full article

Background/Objectives: Vaccine elicitation of antibodies with high HIV-1 neutralization breadth is a long-standing goal. Recently, the induction of such antibodies has been achieved at the fusion peptide site of vulnerability. Questions remain, however, as to how much anti-fusion peptide antibodies can be improved and whether their neutralization breadth and potency are sufficient to prevent HIV-1 infection. Methods: Here, we use yeast display coupled with deep mutational screening and biochemical and structural analyses to study the improvement of the best fusion peptide-directed, vaccine-elicited antibody, DFPH_a.01, with an initial 59% breadth. Results: Yeast display identified both single and double mutations that improved recognition of HIV-1 envelope trimers. We characterized two paratope-distal light chain (LC) mutations, S10R and S59P, which together increased breadth to 63%. Biochemical analysis demonstrated DFPH-a.01_10R59P-LC, and its component mutations, to have increased affinity and stability. Cryo-EM structural analysis revealed elbow-angle influencing by S10R-LC and isosteric positioning by S59P-LC as explanations for enhanced breadth, affinity, and stability. Conclusions: These results, along with another antibody with enhanced performance (DFPH-a.01_1G10A56K-LC with 64% breadth), suggest that mutations improving DFPH_a.01 are plentiful, an important vaccine insight. Full article

Background: HIV-1 envelope (Env) variable loops 1 and 2 (V1V2) directed non-neutralizing antibodies were a correlate of decreased transmission risk in the RV144 vaccine trial. Thus, the elicitation and breadth of antibody responses against the V1V2 of HIV-1 Env are important considerations for HIV-1 vaccine candidates. The V1V2 region’s highly variable nature and the extensive diversity of subtype C HIV-1 Envelopes (Envs) make the V1V2 response breadth a high priority for HIV-1 vaccine regimens aiming for V1V2-mediated protection in Southern Africa. Here, we determined whether the breadth of the anti-V1V2 vaccine response can be broadened by including HIV-1 Env strains computationally designed to enhance the coverage of subtype C V1V2 sequence diversity. Methods: Three subtype C Env strains were selected to maximize antibody binding coverage while complementing subtype C vaccine gp120s that were given in human clinical trials in South Africa, as well as to improve epitope accessibility. Humoral immunogenicity of a novel trivalent gp120 vaccine immunogen, a bivalent gp120 boost already in clinical trials (1086C and TV1), and a pentavalent (all five gp120s combined) were evaluated in a preclinical immunization study in guinea pigs. The pentavalent combination was further evaluated with alum versus glucopyranosyl lipid adjuvants formulated in squalene-in-water emulsion (GLA-SE) adjuvants in non-human primates. The breadth of the anti-V1V2 response was assessed using an array of cross-subtype variable loops 1&2 (V1V2) scaffold proteins and linear V2 peptides. Results: The breadth of the IgG response against V1V2 antigens of the trivalent and pentavalent groups was comparable, and both were greater than the breadth of the bivalent group. Linear epitope mapping showed that two linear epitopes in V2 were targeted by the vaccinated animals: the V2 hotspot focused at ¹⁶⁹K that potentially correlated with decreased HIV-1 risk in RV144 and the V2.2 site (¹⁷⁹LDV/I¹⁸¹) that is part of the integrin α4β7 binding site. The bivalent vaccine elicited a significantly higher magnitude of binding to the V2 hotspot compared to the trivalent vaccine whereas the trivalent vaccine elicited significantly higher binding to the V2.2 epitope compared to the bivalent vaccine, while the pentavalent recognized both regions. Conclusions: These results demonstrate that the three new computationally selected subtype C Envs successfully complemented 1086C and TV1 for broader V1V2 antibody responses, and, in concert with adjuvants that stimulate V1V2 responses, can be considered as part of a rationale immunogen design to improve V1V2 IgG coverage in future vaccine trials in South Africa. Full article

Background: The increasing prevalence of drug-resistant tuberculosis (TB) underscores the urgent need for novel antimicrobial agents. Methods: This study integrates cultivation optimization, nuclear magnetic resonance (NMR) fingerprinting, and principal component analysis (PCA) to explore microbial secondary metabolites as potential anti-TB agents. Results: Using the combined approach, 11 bioactive compounds were isolated and identified, all exhibiting anti-Mycobacterium bovis BCG activity. Notable findings include borrelidin, a potent threonyl-tRNA synthetase inhibitor with broad biological activities, and L-O-Lac-L-Val-D-O-Hiv-D-Val, a peptide isolated for the first time from a plant endophyte, demonstrating broad-spectrum antimicrobial activity. Additionally, elaiophylin and polycyclic tetramate macrolactams (PTMs) displayed significant bactericidal effects, with elaiophylin achieving complete BCG inhibition at 72 h and PTMs marking their first reported anti-TB activity. The study also identified bafilomycins as potent scaffolds for anti-TB drug development, showcasing rapid bactericidal activity at low MIC values. Conclusions: These findings emphasize the value of microbial metabolites as a reservoir of bioactive compounds and provide new avenues for developing next-generation anti-TB therapies. Full article

Peptide-based inhibitors represent a promising approach for the treatment of HIV-1, offering a range of potential advantages, including specificity, low toxicity, and the ability to target various stages of the viral lifecycle. This review outlines the current state of research on peptide-based anti-HIV therapies, highlighting key advancements and identifying future research directions. Over the past few years, there has been significant progress in developing synthetic peptide-based drugs that target various stages of the viral life cycle, including entry and replication. These approaches aim to create effective anti-HIV therapies. Additionally, peptides have proven valuable in the development of anti-HIV vaccines. In the quest for effective HIV vaccines, discovering potent antigens and designing suitable vaccine strategies are crucial for overcoming challenges such as low immunogenicity, safety concerns, and increased viral load. Innovative strategies for vaccine development through peptide research are, therefore, a key focus area for achieving effective HIV prevention. This review aims to explore the strategies for designing peptides with anti-HIV activity and to highlight their role in advancing both therapeutic and preventive measures against HIV. Full article

Peptides from heptad repeat (HR1 and HR2) regions of gp41 are effective inhibitors of HIV-1 entry that block the fusion of viral and cellular membranes, but the generation of antibodies highly specific for these peptides is challenging. We have previously described a mouse hybridoma that recognizes MT-C34-related peptides derived from HR2. It was used for the selection of HIV-1-resistant CD4 lymphocytes engineered to express the MT-C34 peptide via a CRISPR/Cas9-mediated knock-in into the CXCR4 locus. In this study, we cloned variable domains of this antibody and generated a recombinant chimeric antibody (chAb) by combining it with the constant regions of the humanized antibody Trastuzumab. The new chAb displayed a high specificity and two-fold higher level of affinity than the parental mouse monoclonal antibody. In addition, chAb mediated up to 27–43% of the antibody-dependent cellular cytotoxicity towards cells expressing MT-C34 on their surface. The anti-MT-C34 chAb can be easily generated using plasmids available for the research community and can serve as a valuable tool for the detection, purification, and even subsequent elimination of HIV-1-resistant CD4 cells or CAR cells engineered to fight HIV-1 infection. Full article

HLA-B27 and HLA-B57 are associated with autoimmunity and long-term viral control and protection against HIV and HCV infection; however, their role in cancer immunity remains unknown. HLA class I molecules interact with innate checkpoint receptors of the LILRA, LILRB and KIR families present in diverse sets of immune cells. Here, we demonstrate that an open format (peptide free conformation) and expression- and stability-optimized HLA-B57-B2m-IgG4_Fc fusion protein (IOS-1002) binds to human leukocyte immunoglobulin-like receptor B1 and B2 (LILRB1 and LILRB2) and to killer immunoglobulin-like receptor 3DL1 (KIR3DL1). In addition, we show that the IgG4 Fc backbone is required for engagement to Fcγ receptors and potent activation of macrophage phagocytosis. IOS-1002 blocks the immunosuppressive ITIM and SHP1/2 phosphatase signaling cascade, reduces the expression of immunosuppressive M2-like polarization markers of macrophages and differentiation of monocytes to myeloid-derived suppressor cells, enhances tumor cell phagocytosis in vitro and potentiates activation of T and NK cells. Lastly, IOS-1002 demonstrates efficacy in an ex vivo patient-derived tumor sample tumoroid model. IOS-1002 is a first-in-class multi-target and multi-functional human-derived HLA molecule that activates anti-tumor immunity and is currently under clinical evaluation. Full article

Cell-penetrating peptides (CPPs) are promising carriers to effectively transport antisense oligonucleotides (ASOs), including peptide nucleic acids (PNAs), into bacterial cells to combat multidrug-resistant bacterial infections, demonstrating significant therapeutic potential. Streptococcus suis, a Gram-positive bacterium, is a major bacterial pathogen in pigs and an emerging zoonotic pathogen. In this study, through the combination of super-resolution structured illumination microscopy (SR-SIM), flow cytometry analysis, and toxicity analysis assays, we investigated the suitability of four CPPs for delivering PNAs into S. suis cells: HIV-1 TAT efficiently penetrated S. suis cells with low toxicity against S. suis; (RXR)₄XB had high penetration efficiency with inherent toxicity against S. suis; (KFF)₃K showed lower penetration efficiency than HIV-1 TAT and (RXR)₄XB; K8 failed to penetrate S. suis cells. HIV-1 TAT-conjugated PNA specific for the essential gyrase A subunit gene (TAT-anti-gyrA PNA) effectively inhibited the growth of S. suis. TAT-anti-gyrA PNA exhibited a significant bactericidal effect on serotypes 2, 4, 5, 7, and 9 strains of S. suis, which are known to cause human infections. Our study demonstrates the potential of CPP-ASO conjugates as new antimicrobial compounds for combating S. suis infections. Furthermore, our findings demonstrate that applying SR-SIM and flow cytometry analysis provides a convenient, intuitive, and cost-effective approach to identifying suitable CPPs for delivering cargo molecules into bacterial cells. Full article