The rapid transmission of SARS-CoV-2 in the USA and worldwide necessitates the development of multiple vaccines to combat the COVID-19 global pandemic. Previously, we showed that a particulate adjuvant system, quil-A-loaded chitosan (QAC) nanoparticles, can elicit robust immunity combined with plasmid vaccines when used against avian coronavirus. Here, we report on the immune responses elicited by mucosal homologous plasmid and a heterologous immunization strategy using a plasmid vaccine and a Modified Vaccinia Ankara (MVA) expressing SARS-CoV-2 spike (S) and nucleocapsid (N) antigens. Only the heterologous intranasal immunization strategy elicited neutralizing antibodies against SARS-CoV-2 in serum and bronchoalveolar lavage of mice, suggesting a protective vaccine. The same prime/boost strategy led to the induction of type 1 and type 17 T-cell responses and polyfunctional T-cells expressing multiple type 1 cytokines (e.g., IFN-γ, TNFα, IL-2) in the lungs and spleens of vaccinated mice. In contrast, the plasmid homologous vaccine strategy led to the induction of local mono and polyfunctional T-cells secreting IFN-γ. Outcomes of this study support the potential of QAC-nano vaccines to elicit significant mucosal immune responses against respiratory coronaviruses.
【저자키워드】 COVID-19, SARS-CoV-2, intranasal vaccine, heterologous vaccine, nanovaccine, 【초록키워드】 neutralizing antibody, Coronaviruses, Vaccine, immune response, Immunity, T-cell Response, lung, Local, cytokine, immunization, global pandemic, serum, mice, nucleocapsid, antigens, T-cell, USA, homologous, intranasal, spleen, Heterologous, IFN-γ, Protective, SARS-CoV-2 spike, IL-2, mucosal, Bronchoalveolar lavage, Plasmid, Support, Homologous vaccine, TNFα, avian coronavirus, vaccinia, transmission of SARS-CoV-2, mucosal immune, robust, elicit, expressing, elicited, responses against, secreting, 【제목키워드】 response, systemic, Localized,