Immunogenicity of peptide 6 in HLA transgenic mice expressing human
HLA-DQA1*0301, DQB1*0302 (DQ8) gene but lacking all four chains of mouse
endogenous class II molecules. LNCs (1 × 106) from transgenic
mice were cultured. Con A (20 µg/mL, positive control) and varying
concentrations of peptide 6 and control peptide. The cells were incubated for 48
h at 37 °C. During the last 18 h, the cells were pulsed with
3H-thymidine (1 µCi/well). At the end of the assay, the
cells were harvested using a plate harvester, and incorporated radioactivity was
determined using an automated counter (Microbeta, Perkin Elmer Wallac). The
results are depicted as delta cpm. There was no significant difference in
response when challenged in vitro by the control peptide or
peptide 6, suggesting that peptide 6 is not immunogenic.