Cutting edge: Expression of Fc?RIIB tempers memory CD8 T cell function in vivo.

ABSTRACT: During reinfection, high-affinity IgG Abs form complexes with both soluble Ag and Ag displayed on the surface of infected cells. These interactions regulate cellular activation of both innate cells and B cells, which express specific combinations of activating Fc?Rs (Fc?RI, Fc?RIII, Fc?RIV) and/or the inhibitory Fc?R (Fc?RIIB). Direct proof for functional expression of Fc?R by Ag-specific CD8 T cells is lacking. In this article, we show that the majority of memory CD8 T cells generated by bacterial or viral infection express only Fc?RIIB, and that Fc?RIIB could be detected on previously activated human CD8 T cells. Of note, Fc?R stimulation during in vivo Ag challenge not only inhibited the cytotoxicity of memory CD8 T cells against peptide-loaded or virus-infected targets, but Fc?RIIB blockade during homologous virus challenge enhanced the secondary CD8 T cell response. Thus, memory CD8 T cells intrinsically express a functional Fc?RIIB, permitting Ag-Ab complexes to regulate secondary CD8 T cell responses.

SUBMITTER: Starbeck-Miller GR 

PROVIDER: S-EPMC3874719 | biostudies-literature | 2014 Jan

REPOSITORIES: biostudies-literature