Figure 2.
Induction of CD4 T cell responses using the dual-phosphorylated p53 peptide. (A) The dual-phosphorylated peptide p-p53S33 and S37-reactive CD4 T cells (J5, J16, and T20) were assessed for their ability to recognize various concentrations of dual-phosphorylated, mono-phosphorylated, and wild type (wt) peptides. Autologous PBMCs were used as antigen presenting cells (APCs). (B) MHC restriction analysis of phosphorylated p53-reactive CD4 T cells. Peptide-induced T cell responses of p-p53S33 and S37-reactive CD4 T cells (J5, J16, and T20) in the presence of anti-HLA DR mAb L243 or anti-HLA class I mAb W6/32 (negative control) were evaluated. Autologous PBMCs were used as APCs. (C) CD4 T cell responses to phosphorylated p53 peptides (J5, J16 and T20) were measured using L-cells transfected with individual HLA-DR genes as APCs to determine the restricting HLA class II molecules.