[Prediction and modification analysis of low-affinity HLA-A*0201 restricted CTL epitopes derived from HIV-1 pol antigen].

Aim: To screen the possible HLA-A*0201 restricted low-affinity CTL epitopes derived from HIV-1 pol antigen and to predict and identify the possible change of the affinity between epitope and the HLA-A*0201 molecule when the epitope is modified.

Methods: HLA-A*0201 restricted low-affinity CTL epitopes were predicted by CTL epitope prediction software based on super motif, proteasome cleavage probability, HLA affinity and so on. The candidates were modified acid substitution and analyzed by computer. T2 cells were used to determine the peptide by amino binding affinity and HLA-A*0201-peptide complex stability.

Results: Among the three predicted peptides by softer ware, YVSLSFPQI (pol52-60Y1), YVSQIIEQL pol(673-681Y1), YIQKETWEA(pol548-556Y1)could bind to HLA-A*0201 with high affinity, and the dissociation time of 50% HLA-A*0201 peptide complex was over to 8 h.

Conclusion: Our results suggest that the three predicted peptides, as modification, might be HLA-A*0201 restricted CTL epitopes.