Abstract
Respiratory transmission of SARS-CoV-2 is considered to be the major dissemination route for COVID-19, therefore, mucosal immune responses have great importance in preventing SARS-CoV-2 from infection. In this study, we constructed a recombinant Vaccinia virus (VV) harboring trimeric receptor-binding domain (RBD) of SARS-CoV-2 spike protein (VV<sub>-tRBD</sub>), and evaluated the immune responses towards RBD following intranasal immunization against mice and rabbits. In BALB/c mice, intranasal immunization with VV<sub>-tRBD</sub> elicited robust humoral and cellular immune responses, with high-level of both neutralizing IgG and IgA in sera against SARS-CoV-2 psudoviruses, and a number of RBD-specific IFN-γ-secreting lymphocytes. Sera from immunized rabbits also exhibited neutralization effects. Notably, RBD-specific secretory IgA (sIgA) in both nasal washes and bronchoalveolar lavage fluids (BALs) were detectable and showed substantial neutralization activities. Collectively, a recombinant VV expressing trimeric RBD confers robust systemic immune response and mucosal neutralizing antibodies, thus warranting further exploration as a mucosal vaccine.
Keywords: Neutralization; SARS-CoV-2; Trimeric RBD; Vaccinia virus.
【저자키워드】 SARS-CoV-2, neutralization, vaccinia virus., trimeric RBD, 【초록키워드】 COVID-19, IgG, Vaccine, immune response, Lymphocytes, Neutralizing antibodies, Infection, virus, immunization, Bronchoalveolar lavage fluid, mice, RBD, IgA, sera, response, SARS-CoV-2 spike protein, Neutralizing, respiratory, dissemination, intranasal, mucosal, secretory IgA, humoral, systemic immune response, domain, cellular immune responses, neutralization activities, BALB/c mice, vaccinia, transmission of SARS-CoV-2, mucosal immune, Effects, immunized, trimeric, robust, detectable, evaluated, exhibited, expressing, elicited, nasal washe, 【제목키워드】 neutralizing antibody, virus, immunization, SARS-CoV-2 spike, domain, vaccinia, trimeric, induce,