bronchitis vaccine

γ-Amino acid-containing natural products of bacterial origin: structure, biosynthesis, and bioactivity.

Götze Sebastian S, Decker Tanya T, Balluff Sven S, Beemelmanns Christine C

Covering: 1966 to 2026γ-Amino acids are structurally diverse non-proteinogenic building blocks that endow bacterial natural products with unique conformational, physicochemical, and biological properties. Although individual γ-amino acid-containing metabolites have been extensively investigated, their structural diversity, biosynthetic origins, and functional significance have rarely been considered from a unified perspective. Here, we review nearly six decades of research on bacterial γ-amino acid-containing natural products, covering from 1966 and the discovery of bleomycin to genome-guided discoveries in 2026. We discuss the major structural classes of γ-amino acids, including GABA-derived, β-keto, statine-type, vinylogous, fully reduced, and masked amino acid-derived motifs, and highlight how these building blocks are generated through primary metabolism, hybrid NRPS-PKS assembly lines, and specialized tailoring reactions. Particular emphasis is placed on the relationships between γ-amino acid structure, biosynthetic logic, and biological function, including their roles in protease inhibition, covalent target engagement, metallophore activity, and microbial ecology. Finally, we discuss emerging opportunities for genome mining and biosynthetic engineering that are expected to accelerate the discovery and exploitation of γ-amino acid-containing natural products.

Immunogenicity and protective efficacy of recombinant BCG expressing a multi-epitope vaccine against mycobacterium tuberculosis.

Zhang Xuan-Ji XJ, Luo Jia-Rui JR, Tian Ting-Ting TT, Shi Juan J et al.

Mycobacterium tuberculosis (Mtb) infects approximately one-quarter of the global population, of whom 5%-10% develop active tuberculosis (TB). Although Bacillus Calmette-Guérin (BCG) remains the cornerstone vaccine against severe infant TB, its efficacy in adults is limited, underscoring the need for novel TB vaccines. This study aimed to design a multi-epitope vaccine, tMEV, and validate its protective potential through bioinformatic prediction and in vivo experiments. tMEV was constructed from dominant T- and B-cell epitopes derived from Mtb ESAT-6, PE35, PPE38, and PE4 proteins, fused with an adjuvant. Its vaccine candidacy was assessed via physicochemical and solubility profiling, secondary and tertiary structure modeling, TLR-4 molecular docking, molecular dynamics simulation, and immune simulation. The tMEV coding sequence was cloned into pMV361 and transformed into BCG to generate recombinant BCG (rBCG-tMEV). Immunogenicity, antigenicity, and protective efficacy were evaluated in mouse immunization and Mtb challenge models. tMEV exhibited favorable vaccine-like properties in silico. In mice, both tMEV and rBCG-tMEV induced Mtb-specific immune responses. Compared with PBS, tMEV significantly enhanced cellular and humoral immunity with a Th2-biased profile. Relative to conventional BCG, rBCG-tMEV elicited a superior mixed Th1-Th2 response and higher antigen-specific immunity, accompanied by increased secretion of IFN-γ, IL-2, TNF-α, granzyme B, and perforin. Moreover, rBCG-tMEV markedly reduced bacterial loads in the lungs and spleens of Mtb-infected mice, conferring partial protection. These findings demonstrate that tMEV and rBCG-tMEV possess robust immunogenicity and protective potential against Mtb, representing promising novel TB vaccine candidates and providing a rationale for future vaccine development and optimization.

A Phase 1/2 Trial Evaluating the Safety and Immunogenicity of an mRNA-based Seasonal Influenza Vaccine Candidate Encoding Hemagglutinin and Neuraminidase.

De Coster Ilse I, Cardona Jose F JF, Ferguson Murdo M, Leroux-Roels Isabel I et al.

Hemagglutinin (HA) is the principal immunologic target of most licensed seasonal influenza vaccines. Targeting both HA and neuraminidase (NA) might improve vaccine effectiveness. This randomized phase 1/2 study evaluated an investigational mRNA-based quadrivalent seasonal influenza vaccine, encoding HA and NA of A/H1N1, A/H3N2, B/Victoria, and B/Yamagata (FLUm4HA-4NA). In phase 1, adults aged 18-50 years received either one of twelve mRNA vaccine formulations of varying HA-only or HA and NA mRNA doses, or a licensed quadrivalent seasonal influenza comparator. In phase 2, participants aged 18-64 years (younger adults) and 65-85 years (older adults) received FLUm4HA-4NA (three groups per age category, with different HA/NA mRNA doses) or age-appropriate licensed quadrivalent comparator. Primary endpoints were safety/reactogenicity, and hemagglutination inhibition [HI] and NA inhibition [NI] responses against the four seasonal strains at day 29. Cross-reactive HI/NI responses against drifted strains, virus neutralization, and HA-/NA-specific cell-mediated immunity were evaluated in phase 2 as tertiary objectives. A total of 293 participants (21-25 per group) were vaccinated in phase 1, 480 younger (108-137 per group) and 483 older adults (117-125 per group) in phase 2. Solicited events were more frequent with FLUm4HA-4NA than comparators and were mostly short-lived and mild or moderate. No deaths or vaccine-related serious adverse events were reported. Post-vaccination HI and neutralizing titers in the FLUm4HA-4NA groups were similar or higher for the A strains and lower for the B strains versus comparators. NI responses exceeded those of comparators for all four strains. HI and NI titers against evaluated drifted A strains were similar or higher after FLUm4HA-4NA than after comparator vaccination. HA-specific CD4+ and CD8+ T-cell responses were generally higher after FLUm4HA-4NA than comparator vaccination. FLUm4HA-4NA showed an acceptable safety profile and humoral and cellular immunogenicity in the study population, supporting further development and formulation optimization to improve influenza B HI responses. ClinicalTrials.gov: NCT05823974; euclinicaltrials.eu: 2022-502308-66-00.

Correction to "Screening Natural Cholesterol Analogs to Assemble Self-Adjuvant Lipid Nanoparticles for Antigens Tagging Guided Therapeutic Tumor Vaccine".