Immune-Modulation by Epidermal Growth Factor Receptor Inhibitors: Implication on Anti-Tumor Immunity in Lung Cancer
Fig 5
EGFR inhibitor increases antigen specific T cell mediated tumor killing.
(A) The expression of HLA-A2 on HLA-A2+ lung cancer cell line, H441, was confirmed using flowcytometry. (B) Mart-1 (M27) specific cytotoxic T cell line (CTL), 1007G, was stained with anti-CD3 and Mart-1 (M27)/HLA-A2 tetramer to confirm the antigenic specificity. More than 90% of T cells expressed T cell receptors specific for Mart-1(M27)/HLA-A2 tetramers. (C) H441 cells pretreated with or without erlotinib in the presence or absence of Mart-1(M27) or pp65 control peptide were used as target cells for standard cytotoxic T cell (CTL) assay using Mart-1(M27) specific CTLs as effector T cells. Percent Specific cytotoxicity was calculated as follows: [(test release-spontaneous release)/(maximum release-spontaneous release)] × 100. Mart-1 (M27) specific CTL efficiently lysed H441 only in the presence of Mart-1 peptide but not control peptide, and the treatment of erlotinib significantly increased T cell mediated killing. The experiment shown here was performed in quadruplicates, and a representative of two independent experiments.