Characterization of LANA-specific CD4⁺ T-cell clones. T-cell clones from donor G48 and B1 were screened for IFN-γ secretion by ELISA when incubated with the pools of LANA peptides (A,E) and then the individual peptides within the reactive pools (B,F). The HLA restriction of the clones was then determined by testing the clones for IFN-γ release when challenged with partially HLA-matched LCLs sensitized with the clone's cognate peptide (C,G). Functional avidity of the clones was determined by incubating the clones with LCLs sensitized with 10-fold dilutions of cognate peptide and then assaying for IFN-γ secretion (D,H). Map of novel epitopes within LANA. Hatched region represents the acidic repeat region of LANA (I).