In vitro and ex vivo characterization of lectin-labeled Mycobacterium tuberculosis antigen-containing microspheres for enhanced oral delivery.

Purpose: Oral immunization for mucosal protection against Mycobacterium tuberculosis would be the best option for effective tuberculosis (TB) control. However, this route of vaccine delivery is limited due to the short residence time of the delivery system at the site of absorption. Cytoadhension has made it possible to optimize the targeted delivery of oral vaccine to lymphoid tissues. The purpose of this project was to evaluate the ability of human M-cell specific lectin-labeled microparticles to target the human M-cells of the Peyer's patches.

Method: Albumin microspheres containing Mycobacterium tuberculosis cell lysate antigens were coupled with Wheat germ agglutinin and Aleuria aurantia lectins and their ability to bind to M cell models as well as their preferential distribution in the Peyer's patches were investigated.

Results: The study demonstrated an enhanced delivery of targeted polystyrene and BSA/Lysate microspheres to M cells. It was demonstrated that alpha-l-fucose sugar residue might be the target of these lectins.

Conclusion: It can be concluded from the study that the lectin-coupled microspheres had better affinity for M-cells and showed preferential binding to the Peyer's patches. This means that the coupling enhanced the targeted delivery of the antigens to the M cells.