Immunogenicity of PreF and PostF recombinant protein vaccines against respiratory syncytial virus / 中华微生物学和免疫学杂志

ABSTRACT

Objective:To compare the immunogenicity of the prefusion (PreF) and postfusion (PostF) conformations of the respiratory syncytial virus (RSV) F protein.Methods:The expression of PreF and PostF recombinant proteins was analyzed by SDS-PAGE and Western blot. The binding affinity between F protein and its specific antibodies was detected by Octet. The binding antibodies and neutralizing antibodies in immune serum were detected after immunizing mice with PreF or PostF recombinant protein.Results:PreF protein was stable in the form of a trimer after modification with higher binding affinity with monoclonal antibodies such as D25, 8897, AM14, Palivizumab and Motavizumab. PostF protein lacked the antigenic site ? and showed a monomer conformation. Besides, it was unable to bind to D25, 8897 and AM14 antibodies. Animal experiments showed that AS01 adjuvant was better than aluminum adjuvant in inducing binding antibodies and neutralizing antibodies against RSV Long strains. The binding antibodies induced by PreF and PostF recombinant proteins had similar binding ability to PreF protein, while the binding antibodies induced by PostF recombinant protein showed stronger binding ability to PostF than to PreF.Conclusions:PreF has more epitopes and the trimer form of PreF recombinant protein after modification is more stable and can induce stronger neutralizing antibodies. Moreover, the immunopotentiating effect of AS01 adjuvant is better than that of aluminum adjuvant. Therefore, stabilization-based trimer structure modification of PreF and the development of adjuvants are crucial for the development of RSV vaccines.