Distinct B-cell populations contribute to vaccine antigen-specific antibody production in a transgenic mouse model

Abstract

The generation of memory B cells by vaccination plays a critical role in maintaining antigen-specific antibodies and producing antibody responses upon re-exposure to a pathogen. B-cell populations contributing to antibody production and protection by vaccination remain poorly defined. We used influenza virus-like particle (VLP) vaccine in a transgenic mouse model that would identify germinal centre-derived memory B cells with the expression of yellow fluorescent protein (YFP+ cells). Immunization with influenza VLP vaccine did not induce significant increases in YFP+ cells although vaccine antigen-specific antibodies in sera were found to confer protection against a lethal dose of influenza A virus (A/PR8). In addition, CD43+ B220- populations with low YFP+ cells mainly contributed to the production of vaccine antigen-specific IgG isotype-switched antibodies whereas CD43- B220+ populations with high YFP+ cells were able to produce vaccine antigen-specific IgM antibodies. Challenge infection of immunized transgenic mice with live influenza A virus resulted in significant increases in YFP+ cells in the B220- populations of spleen and bone marrow cells. These results suggest that CD43+ B220- B cells generated by vaccination are important for producing influenza vaccine antigen-specific antibodies and conferring protection. © 2014 John Wiley & Sons Ltd.