Influenza vaccines produce highly variable B cell responses among individuals, making it difficult to predict who will achieve protective antibody titers after vaccination.
In this paper by Henn AD et al., 2013, daily sampling of serum, peripheral blood mononuclear cells (PBMC), B cells and plasma cells from 14 human subjects was performed over 11 days post-influenza inactivated vaccine administration. Peripheral blood was drawn during the week prior to vaccination (pre-V), immediately before vaccination (day 0), daily for days 1–10 and on day 21 post-vaccination.
Most differentially expressed genes were detected at days 5-6 post vaccination, and this corresponded with the heightened IgM, IgG, plasmablast and activated ASC responses in most subjects. Many of these transcripts were validated to be B cell differentiation genes.
742 genes were differentially regulated temporally, and the majority of these genes were significantly correlated with CD27hiCD38hiCD138− plasmablasts. These genes are termed as the plasma cell gene signature (PCgs).
Ten of the top 30 categories of functionally related genes in the PCgs involved ER function and protein production. These findings are consistent with involvement of the PCgs in program-level upregulation of antibody production machinery and the unfolded protein response seen during plasma cell development.
Of interest, the other genes involved in the PCgs were expressed by the myeloid/DC lineages, many of which peaked at day 1. This is consistent with the notion that the magnitude of the innate immune response is also associated with antibody responses from influenza vaccination.