T Cell Activating Thermostable Self-Assembly Nanoscaffold Tailored for Cellular Immunity Antigen Delivery.

Area of Science:

• Biotechnology
• Immunology
• Nanotechnology

Background:

• Antigen delivery using self-assembling protein nanoscaffolds like Aquifex aeolicus lumazine synthase (AaLS) is hindered by immunotoxicity and premature clearance.
• Unregulated innate immune responses can compromise the efficacy of antigen-scaffold complexes.

Purpose of the Study:

• To develop a novel, thermostable self-assembling nanoscaffold (RP_T) for enhanced T cell-mediated immunity.
• To construct nanovaccines using RP_T for improved antigen delivery and immune activation.

Main Methods:

• Utilized immunoinformatics prediction and computational modeling to screen T epitope peptides from thermophilic nanoproteins.
• Engineered RP_T nanoscaffolds and loaded them with model antigens (ovalbumin T epitopes, SARS-CoV-2 RBD) via the SpyCather/SpyTag system.
• Evaluated nanovaccine immunogenicity, antigen stability, and immune cell differentiation in vitro and in vivo.

Main Results:

• RP_T-based nanovaccines induced more potent cytotoxic T cell and CD4+ T helper 1 (Th1)-biased immune responses compared to AaLS.
• RP_T nanovaccines generated less anti-scaffold antibody and enhanced antigen stability against heat, freeze-thawing, and lyophilization.
• RP_T promoted type-1 conventional dendritic cell differentiation, enhancing antigen cross-presentation to CD8+ T cells and Th1 polarization.

Conclusions:

• The novel RP_T nanoscaffold offers a safe and robust platform for developing T-cell immunity-dependent vaccines.
• RP_T overcomes limitations of existing nanoscaffolds by reducing immunotoxicity and improving antigen stability.
• This strategy holds significant potential for advancing vaccine development against infectious diseases and cancer.