Biodegradable polyelectrolyte microcapsules: antigen delivery tools with Th17 skewing activity after pulmonary...

Area of Science:

• Immunology
• Materials Science
• Nanotechnology

Background:

• The lungs offer a large surface area for noninvasive vaccine delivery, potentially inducing both local mucosal and systemic immunity.
• Adjuvants are crucial for adaptive immunity, enhancing immune response strength and directing the type of response.
• Polyelectrolyte microcapsules (PEMs) represent a new class of microcapsules formed from charged polymers.

Purpose of the Study:

• To evaluate the adjuvant properties of polyelectrolyte microcapsules (PEMs) for pulmonary vaccine delivery.
• To assess PEMs' ability to induce immune responses, specifically Th17 polarization.
• To determine the efficacy of antigen (Ag) encapsulation within PEMs for enhancing immune responses.

Main Methods:

• PEMs were synthesized using sequential adsorption of dextran-sulfate and poly-L-arginine onto a sacrificial template.
• PEMs were administered intratracheally to assess uptake by antigen-presenting cells (APCs) and their activation status.
• Immune responses were analyzed, focusing on Th17 polarization and local mucosal immunity.

Main Results:

• PEMs were efficiently taken up by pulmonary APCs, enhancing their activation.
• Intratracheal instillation of PEMs induced a strongly Th17-polarized immune response.
• Encapsulating antigens within PEMs significantly boosted the local mucosal immune response compared to soluble antigen with empty microcapsules.

Conclusions:

• PEMs demonstrate significant potential as adjuvants for pulmonary vaccine delivery.
• Their ability to selectively induce Th17-polarized immune responses makes them promising for vaccines against fungal and bacterial pathogens.
• PEMs offer a novel platform for developing effective mucosal vaccines.