Peritoneal administration of a subunit vaccine encapsulated in a nanodelivery system not only augments systemic responses against sars-cov-2 but also stimulates responses in the respiratory tract

• Main Authors: Tuksin Jearanaiwitayakul, Suttikarn Apichirapokey, Runglawan Chawengkirttikul, Jitra Limthongkul, Mathurin Seesen, Phissinee Jakaew, Sakalin Trisiriwanich, Sompong Sapsutthipas, Panya Sunintaboon, Sukathida Ubol
• Other Authors: Thailand Ministry of Public Health
• Format: Article
• Published: 2022
• Subjects: Immunology and Microbiology; Medicine
• Online Access: https://repository.li.mahidol.ac.th/handle/123456789/77200
• Institution: Mahidol University

The COVID-19 pandemic has currently created an unprecedented threat to human society and global health. A rapid mass vaccination to create herd immunity against SARS-CoV-2 is a crucial measure to ease the spread of this disease. Here, we investigated the immunogenicity of a SARS-CoV-2 subunit vaccine candidate, a SARS-CoV-2 spike glycoprotein encapsulated in N,N,N-trimethyl chitosan particles or S-TMC NPs. Upon intraperitoneal immunization, S-TMC NP-immunized mice elicited a stronger systemic antibody response, with neutralizing capacity against SARS-CoV-2, than mice receiving the soluble form of S-glycoprotein. S-TMC NPs were able to stimulate the circulating IgG and IgA as found in SARS-CoV-2-infected patients. In addition, spike-specific T cell responses were drastically activated in S-TMC NP-immunized mice. Surprisingly, administration of S-TMC NPs via the intraperitoneal route also stimulated SARS-CoV-2-specific immune responses in the respiratory tract, which were demonstrated by the presence of high levels of SARS-CoV-2-specific IgG and IgA in the lung homogenates and bronchoalveolar lavages of the immunized mice. We found that peritoneal immunization with spike nanospheres stimulates both systemic and respiratory mucosal immunity.