Abstract:

 Objective To predict and identify HLA-A2-restricted CTL epitopes from ovarian cancer-associated antigen TM4SF1. Methods Four prediction programs（BIMAS，SYFPEITHI，IEDB，PROPRED I）were used to predict HLA-A2-restricted CTL epitopes of TM4SF1. Immunoreactivity of these predicted epitopes was measured using ELISOPT directly and in culture. Results Ten candidate CTL epitopes （P1-P10） were screened，and four （P1，P2，P8，P10） were analyzed further for immunoreactivity. SFC was significantly higher in culture ELISPOT than direct ELISPOT for the positive control peptide （322±8 vs 169±22，P<0.05），epitope P1 （114±10 vs 39±7，P<0.05），and epitope P10 （156±31 vs 52±8，P<0.05）. Similarly，average spot size was significantly greater in culture ELISPOT than direct ELISPOT for the positive control peptide （21.91±2.45 vs 13.80±1.76，P<0.05），P1 （12.90±0.88 vs 8.31±1.40，P<0.05），and P10 （17.50±3.85 vs 11.96±0.61，P<0.05）. These results show that culture ELISPOT is more sensitive than direct ELISPOT，and that the SFC T value is higher for epitope P10 than P1. Conclusions Combining four prediction programs is an effective strategy to identify better candidate epitopes and avoid limitations of a single prediction program. Culture ELISPOT is more sensitive than the direct assay for verifying the immunoreactivity of predicted epitopes. The immunoreactivity of P10 is strongest.

Key words: Ovarian neoplasms, TM4SF1, HLA-A2 restricted CTL epitope, Immunoreactivity