Figure 3.

Naturally processed peptide in EL-4 cell extract coelutes with synthetic AFV8 in HPLC analysis. (A) Small molecular weight material in a 0.1% TFA extract of 6 × 10⁷ EL-4 cell equivalents was fractionated on a C₁₈ reverse-phase column by HPLC using an acetonitrile gradient. Fractions were collected at 1-min intervals, dried, resuspended, and tested for activity using K^b-L cells as APCs. KZ30.6 response was measured by the lacZ activity as described in Fig. 1. (B) HPLC fractions from synthetic AFV8 peptide run under identical conditions were analyzed similarly. Mock runs following injection of 0.1% TFA alone were performed prior to each sample and analyzed in parallel to ensure absence of cross-contamination between sample runs.