The CD28/B7 Pathway Costimulates the Response of Primary Murine T Cells to Superantigens as Well as to Conventional Antigens

While the CD28/B7 pathway has been shown to play an important costimulatory role in the response of T cells to conventional antigens, its role in superantigen-mediated T cell activation has not been as clear. In this report, we used CD4+ T cells from ovalbumin-specific αβ-TCR-transgenic mice (DO11.10) to compare the ability of this pathway to costimulate the response of primary T cells to conventional antigens and superantigens. We show that either the addition of anti-CD28 monoclonal antibody or presentation with a B7 transfected cell line enhances the proliferative and interleukin-2 secretion response of DO11.10 CD4+ cells to both the conventional antigen, ovalbumin peptide (OVA 323-339), and the superantigen SEB. This implies that CD28-mediated costimulation plays a role in the response of murine T cells to superantigens as well as to conventional antigens.