Specificity and functional capacity of IDO5-specific T cells assayed by ⁵¹Cr-release assays.

Abstract

<p><i>(</i><i>a</i><i>),</i> Lysis by the IDO5-specific T-cell clone (RBS35) of the HLA-A2⁺/IDO⁺ melanoma cell line FM55M without and with the addition of cold T2-cells pulsed with IDO5 peptide or an irrelevant peptide (HIV-1 pol_476-484) (inhibitor to target ratio  = 20∶1), and NK cell activity of RBS35 examined using the natural killer cell line K562 as target cells. <i>(</i><i>b</i><i>),</i> Lysis by RBS35 of AML-blasts enriched from 5 HLA-A2⁺ AML patients and 1 HLA-A2^- AML patient. B cells and T cells were depleted from the bone marrow of the AML patients using CD19⁺ and CD3⁺ microbeads, respectively. The highly enriched AML-blasts were used as target cells with or without the addition of the HLA-class I specific antibody W6/32. <i>(</i><i>c</i><i>),</i> Lysis of T2-cells pulsed with IDO5 peptide or an irrelevant peptide (HIV-1 pol_476-484), and lysis of the HLA-A2⁺/IDO⁺ colon cancer cell line SW480 by an IDO5-specific T-cell bulk culture. <i>(</i><i>d</i><i>),</i> Lysis of the HLA-A2⁺/IDO⁺ colon cancer cell line SW480 and HLA-A2⁺/IDO^- colon cancer cell line HCT-116 by three different IDO5-specific T-cell clones (RBS26 (<i>white triangle</i>), RBS31 (<i>black triangle</i>), RBS46 (<i>grey triangle</i>)) assayed by ⁵¹Cr-release assay. All assays were performed in different E∶T ratios.</p