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
Tuksin Jearanaiwitayakul,
Suttikarn Apichirapokey,
Runglawan Chawengkirttikul,
Jitra Limthongkul,
Mathurin Seesen,
Phissinee Jakaew,
Sakalin Trisiriwanich,
Sompong Sapsutthipas,
Panya Sunintaboon,
Sukathida Ubol
Affiliations
Tuksin Jearanaiwitayakul
Department of Microbiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
Suttikarn Apichirapokey
Department of Microbiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
Runglawan Chawengkirttikul
Department of Microbiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
Jitra Limthongkul
Department of Microbiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
Mathurin Seesen
Department of Microbiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
Phissinee Jakaew
Department of Microbiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
Sakalin Trisiriwanich
Institute of Biological Products, Department of Medical Sciences, Ministry of Public Health, Nonthaburi 11000, Thailand
Sompong Sapsutthipas
Institute of Biological Products, Department of Medical Sciences, Ministry of Public Health, Nonthaburi 11000, Thailand
Panya Sunintaboon
Department of Chemistry, Faculty of Science, Mahidol University, Salaya, Nakornpatom 73170, Thailand
Sukathida Ubol
Department of Microbiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
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.