A matter of delivery: nanocarriers and the engineering of protective immunity in tuberculosis vaccination

The development of effective subunit vaccines against Mycobacterium tuberculosis (Mtb) is limited by the absence of antigen delivery systems capable of inducing strong cellular immunity. Although nanoparticle (NP) technologies have transformed other areas of vaccinology and nanomedicine, their systematic application in tuberculosis (TB) vaccine development remains underexplored. This dissertation addresses this gap by focusing on the rational design and comparative evaluation of NP-based delivery platforms for TB subunit vaccines.The research scope includes cationic liposomes, pH-sensitive liposomes, poly(lactic-co-glycolic) acid (PLGA) NPs, and lipid–PLGA hybrid systems formulated with the rationally designed Mtb fusion antigen Ag85B–ESAT6–Rv2034. In vitro studies using primary dendritic cells and epitope-specific T-cell assays were employed to assess cellular uptake and immune activation. Key techniques included NP physicochemical characterization, flow cytometry, cytokine and chemokine profiling, and functional T-cell readouts.In vivo evaluation was performed in mouse models using subcutaneous and intradermal immunization, followed by intranasal challenge with virulent Mtb H37Rv. Immune responses were analyzed by multiparameter flow cytometry, antibody profiling, and bacterial burden assessment. By integrating in vitro mechanistic studies with in vivo mouse models, this thesis establishes a comprehensive framework for NP-based TB subunit vaccine development and contributes broadly to vaccine delivery and immunoengineering research.