Ag85A-PEGylated Propolis Nanoparticles Exhibit Intracellular Antimycobacterial and Host-Protective Activities Against Mycobacterium tuberculosis.

Tuberculosis (TB), caused by the intracellular pathogen Mycobacterium tuberculosis (Mtb), remains a major global health challenge. The prolonged duration of treatment and the emergence of multidrug-resistant strains have highlighted the need for alternative therapeutic strategies. This study investigated the therapeutic potential of Ag85A aptamer-conjugated PEGylated niosomes encapsulating ethanolic extract of propolis (Ag85A-PEGNio/EEP) using Mtb-infected macrophage model. Ag85A-PEGNio/EEP exhibited efficient cellular uptake, with more than 99.8% internalization by macrophages, and trafficked host phagolysosome, facilitating targeted delivery of EEP to intracellular Mtb. Ag85A-PEGNio/EEP treatment showed an anti-mycobacterium efficacy by reducing intracellular Mtb viability by approximately 51.2% compared with untreated controls. Moreover, Ag85A-PEGNio/EEP modulated macrophage immune responses by significantly increasing the expression of the pro-inflammatory cytokines IL-12 (8.4-fold) and IL-6 (3.8-fold), while markedly decreasing the expression of the anti-inflammatory cytokine IL-10 (6.4-fold). Protein-protein interaction (PPI) network analysis further revealed the association of proteins with immune regulation and antioxidant responses in treated cells. These findings suggest that Ag85A-PEGNio/EEP functions as a dual-action therapeutic platform by enhancing intracellular anti-mycobacterial activity while balancing host immune responses. This targeted nano-delivery system represents a promising candidate for host-directed TB therapy and further investigations are needed to validate these outcomes and explore their potential applications against TB treatment challenges.