Figure 4. LMP2a gene-transduced γδ T APCs induce peptide-specific CTLs within a population of CD8+ autologous responder T cells.
(A) Purified CD8+ T cells from a normal donor (HLA type A2;25/B15(62)) were coincubated with autologous γδ T cells retrovirally transduced with either control (14.G2aζ) or LMP2a gene for 12 days, followed by quantification of HLA A2-restricted FLY pentamer-positive cells by flow cytometry. (B) The breadth of the LMP2 epitope specificity of a CTL line initiated using γδ T cells transduced with retrovirus LMP2 (LMP2-CTL) was compared to a CTL line initiated with an autologous lymphoblastoid cell line (EBV-CTL). CTLs (1×105/well) (HLA-A2;25/B15(62)) were stimulated with an LMP2-peptide library pooled into 20 pools. Responses were measured in an 18-hour IFN-γ ELISPOT assay. All peptides were divided into 20 pools in such a way that each peptide is present in 2 pools. Shown is one of two experiments with two donors. (C) Responses to these peptide pools could subsequently be mapped to 3 different epitopes (HLA-A2- restricted FLYALALLL, HLA-A25- restricted TVMSNTLLSAW and a further epitope the restriction of which is yet to be determined LALSLLLLLAAVASSY) demonstrating that the breadth of the LMP2-specific T cell response is similar in both EBV-CTL and LMP-CTL. Shown is mean and standard deviation of duplicate wells.