FIG. 5.

DR or DQ restriction of MSP1a-specific CD4⁺ T-lymphocyte clones. T-lymphocyte clones were cultured with autologous APC and medium (no antigen) or either 25 μg of A. marginale homogenate per ml (A), 2 μg of native MSP1 per ml (B and C), or 10 μg of peptide B per ml (D) and either no MAb or 20 μg of MAb specific for DR-α or DQ-α per ml. An IgG2a isotype control MAb was also included. Results are presented as the mean counts per minute of duplicate cultures. Error bars, SD. Asterisks indicate that the response is significantly lower than the response in the presence of isotype control MAb (P < 0.05). Results are representative of at least two experiments for each clone. Ag, antigen.