Conjugation with loxoribine and mannan improves the immunogenicity of Mycobacterium tuberculosis CFP10-TB10.4 fusion protein

Advances in the Functionalization of Vaccine Delivery Systems: Innovative Strategies and Translational Perspectives

The development of effective vaccines requires a rational design that considers the interaction between antigens, their vectors, and the immune system in addition to the activation of pathways that induce a safe and specific immune response. The efficacy of a vaccine formulation depends on the nature of the antigen, the protection offered by the delivery system, the ability to potentiate the immune response, and the precise release of the immunogen. Carrier systems such as lipid nanoparticles, polymers, exosomes, and microorganisms can be functionalized by chemical, physical, or biological methods to generate selective and improved biodistribution profiles. These methods enhance interaction with target cells, thereby improving immunological efficacy. The conjugation of specific ligands or the modification of parameters such as shape, charge, and size of vectors can enhance the specificity, stability, and efficiency of antigen transport to cellular compartments, thereby facilitating a robust immune response. This study examines modifications in vaccine delivery systems, focusing on biomolecules and physicochemical changes that enhance antigen presentation. Additionally, we examine innovative methods, including microneedles, electroporation, and needle-free systems that show potential for enhancing the immune response.

Novel tuberculosis vaccines based on TB10.4 and Ag85B: State-of-art and advocacy for good practices

Tuberculosis (TB) has plagued humanity in numerous devastating forms for centuries and remains a significant health challenge. Mycobacterium tuberculosis (Mtb), the bacterium responsible for TB, was the leading cause of death among infectious agents until the COVID-19 pandemic emerged. Immunization with the bacillus Calmette-Guérin (BCG) vaccine is one of the primary strategies to mitigate the risk of TB. Despite its widespread use, the current BCG vaccine has limited efficacy, particularly in adults. This review focuses on the rational design of vaccine candidates targeting the antigens TB10.4 and Ag85B. The review discusses the roles of TB10.4 and Ag85B in the virulence of Mtb and notes challenges in their production. Additionally, various protein conjugation strategies to enhance immunogenicity, including linking these antigens to glycans and adjuvants, are considered, as well as the most appropriate analytical methods for characterizing recombinant antigenic proteins and their conjugates. Finally, the associated challenges in developing a vaccine encompassing specific glycans and protein components were highlighted. We claim that using standardized procedures and detailed reporting in protein production and chemical modification can improve the reproducibility and rationalization of biological results. By adhering to these guidelines, the goal of developing an effective vaccine against TB will be best achieved.

Nano-adjuvant based on lipo-imiquimod self-assembly for enhanced foot-and-mouth disease virus vaccine immune responses via intradermal immunization

Excellent adjuvants and proper immunization routes play pivotal roles in activating a robust immune response. Nano-adjuvants have the advantages of enhancing immunogenicity, targeting delivery, and improving stability to provide a new solution for vaccine delivery. In this work, we designed and synthesized a pro-immunostimulant of liposolubility imiquimod derivative IMQP, which was synthesized by reaction of palmitoyl chloride with parent imiquimod (IMQ). Using an inactivated foot-and-mouth disease virus (FMDV) as antigen, and the as-synthesized IMQP containing long carbon chain as nano-adjuvant, we formulated a self-assembled foot-and-mouth disease nano-vaccine (IMQP@FMDV) by re-precipitation method for intradermal (I.D.) immunity vaccination. Because of its small size (∼131.75 ± 41.70 nm) and fat-soluble, the as-fabricated lipid nanoparticles (LNPs) showed promising potential for efficient delivery of antigens to immune cells. Also, lysosomal escape was confirmed by co-localization dendritic cells (DCs). Our findings demonstrated that IMQP nano-adjuvant greatly promoted the expression and secretion of cytokines and chemokines with a balance Th1/Th2 immune response via the I.D. administration. Meanwhile, due to the slowly releasing of IMQ by the hydrolysis of IMQP, IMQP persistently stimulated antigen-presenting cells (APCs) maturation and promoted antigen presentation, and subsequently induced the activation of the related downstream NF-кB and MAPK pathways of the TLR7 signaling pathway, thereby stimulated a robust both humoral and cellular immune response.

Nanocodelivery of an NIR photothermal agent and an acid-responsive TLR7 agonist prodrug to enhance cancer photothermal immunotherapy and the abscopal effect

The immunosuppressive tumor microenvironment (TME) greatly limits the actual outcome of immunotherapy. Therefore, it is urgent to develop appropriate strategies to reshape the TME and ultimately induce a strong immune response. Here, we developed a dual-functional liposome loaded with the photothermal agent IR808 near the infrared region (NIR) and Toll-like-receptor-7 (TLR7) agonist loxoribine prodrug (Lipo@IR808@Loxo) to achieve NIR light-triggered photothermal therapy (PTT) and the targeted delivery of immune adjuvants. Under NIR irradiation, Lipo@IR808@Loxo could greatly improve the efficiency of PTT to directly kill tumor cells and release tumor-associated antigens, which could work together with loaded loxoribine to relieve the immunosuppressive TME, effectively promoting the activation of antigen-presenting cells and subsequent antigen presentation. In this way, Lipo@IR808@Loxo could act as an in situ therapeutic cancer vaccine, eventually inducing a potent antitumor T-cell response. When further combined with immune checkpoint blockade, Lipo@IR808@Loxo-mediated photothermal immunotherapy could not only eliminate the primary tumors but also inhibit the growth of distant tumors, thus enhancing the abscopal effect.

Integrated bioinformatic analyses investigate macrophage-M1-related biomarkers and tuberculosis therapeutic drugs

Tuberculosis (TB) is a common infectious disease linked to host genetics and the innate immune response. It is vital to investigate new molecular mechanisms and efficient biomarkers for Tuberculosis because the pathophysiology of the disease is still unclear, and there aren't any precise diagnostic tools. This study downloaded three blood datasets from the GEO database, two of which (GSE19435 and 83456) were used to build a weighted gene co-expression network for searching hub genes associated with macrophage M1 by the CIBERSORT and WGCNA algorithms. Furthermore, 994 differentially expressed genes (DEGs) were extracted from healthy and TB samples, four of which were associated with macrophage M1, naming RTP4, CXCL10, CD38, and IFI44. They were confirmed as upregulation in TB samples by external dataset validation (GSE34608) and quantitative real-time PCR analysis (qRT-PCR). CMap was used to predict potential therapeutic compounds for tuberculosis using 300 differentially expressed genes (150 downregulated and 150 upregulated genes), and six small molecules (RWJ-21757, phenamil, benzanthrone, TG-101348, metyrapone, and WT-161) with a higher confidence value were extracted. We used in-depth bioinformatics analysis to investigate significant macrophage M1-related genes and promising anti-Tuberculosis therapeutic compounds. However, more clinical trials were necessary to determine their effect on Tuberculosis.