Fig. 1.

Detection of hTERT I540-specific T cells by tetramer in multiple myeloma (MM) patients and healthy volunteers. (a) CD8⁺ T cells from HLA-A*0201⁺ MM patients and healthy volunteers were stained with I540-tetramer and CD8 and analysed by flow cytometry. Annexin V was added to exclude dead cells. Tetramer analysis was repeated after 10 days of stimulation with I540 peptide, autologous irradiated peripheral blood mononuclear cells (PBMC) and cytokines. A tetramer containing the HTLV Tax 11–19 peptide was used as a negative control (not shown). Dots represent the percentage of I540-tetramer⁺ cells per total CD8⁺ T cells of individual patients. The line depicts the median value. (b) I540-tetramer evaluation before and after culture exemplified for the two patients with a significant expansion of cells after a single peptide stimulation. Patient A had stage I disease, patient B suffered from stage III myeloma. Both patients were diagnosed with myeloma 12 months before analysis. Percentages represent I540-tetramer⁺ cells per total CD8⁺ cells. (c) Interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) analysis of PBMC directly isolated ex vivo. Numbers reflect spot forming cells (SFC) per 10⁵ CD8⁺ cells. Medium only (med) was used to determine background secretion, the EBV BMLF-1280–288 peptide was used as a positive control.