Memory T-cell frequencies for AdV hexon protein, EBV LMP2 protein, A fumigatus p41 peptide, and C albicans MP65 protein and expansion of antigen-specific cells. (A) Precursor frequencies of T cells specific for the AdV hexon peptide pool, the EBV LMP2 peptide pool, the A fumigatus Crf1 peptide p41, and the C albicans MP65 peptide pool in PBMCs of 7 different donors assessed by IFN-γ ELISPOT assay. (B) Quantification of A fumigatus p41–specific T cells by HLA DRB1*0401–restricted phycoerythrin-labeled tetramer staining in isolated CD4+ T cells, A fumigatus–specific single-pathogen T-cell lines, and multipathogen-specific lines 14 days after expansion. Depicted are 1 × 106 T cells in isolated CD4+ T cells and 1.5 × 104 T cells for single A fumigatus- and multipathogen-specific T-cell lines (representative example, n = 6). (C) Frequencies of T cells specific for the AdV hexon peptide pool, the EBV LMP2 peptide pool, the A fumigatus Crf1 peptide p41, and the C albicans MP65 peptide pool after 14 days of expansion in single cultures and (D) after 14 days of expansion in multipathogen-specific cultures. Frequencies (A,C,D) were determined by IFN-γ ELISPOT assay and are expressed as SFCs/2 × 105 cells (n ≥ 2).
