Figure 5.

Immunization of mice with gp96-peptide complexes elicits antigen-specific CD4+ T cells. (A) BALB/c mice were immunized with either buffer, liver-derived gp96 complexed with WT L11 peptide (25 µg gp96 complexed with approximately 2.5 ng peptide) or liver-derived gp96 complexed with MT L11 (25 µg gp96 complexed with approximately 2.5 ng peptide) twice intradermally, 1 week apart. One week after the last immunization, spleen cells were cultured in vitro either without peptide, with wild type peptide (WT) or with mutated peptide (MT) at 1 µM for 4 days. ³H-thymidine (0.5 µCi/well) was added to the cultures 18 h before harvesting and proliferation was measured. Data from each of two individual mice for each group are shown. (B) The CD4+ T cell line from A was blocked with anti-CD4 and anti-MHC class II mAbs. CD4+ T cell line TM/JB007 cells (2 x 10⁴) from A were cultured with 5 x 10⁵ of irradiated splenic APCs and mutated L11 peptide (0.1 µM) in the presence of the mAb indicated. The response was blocked by anti-CD4 or -I-E^d mAb, but not by anti-CD8 or anti-I-A^d mAb as in Figure 1B.