Figure 4.

 Cross reactivity of YMDD motif specific cytotoxic T lymphocytes (CTLs) against YIDD and YVDD but not hepatitis B core antigen (HBcAg) 18–27. YMDD cell fraction sorted from patient No 3 after in vitro expansion also killed B-LCL cells pulsed with 1 μg/ml YIDD or YVDD peptide as efficiently as target cells pulsed with YMDD peptide (all induced approximately 35–40% of specific target cell lysis at an effector/target cell (E/T) ratio of 20) but not with hepatitis B virus (HBV) core 18–27 peptide (A, B, and C v D). Non-HLA-A2 B-LCL target cells infected with HBV or pulsed with YMDD were used as controls (E).