Figure 6.

CAR⁺ Vδ2⁺ T Cells Can Cross Present MART1 Tumor Antigen to Responder αβ T Cells Transduced with a Cell-Transduced αβTCR

(A) Expression of CD86 and HLA-DR on pre-expanded Vδ2⁺, post-expanded non-transduced (NTD) Vδ2⁺, and CAR⁺ Vδ2⁺ from multiple donors (data represented as mean ± SEM; n = 3). (B) Schematic representation of a GD2-CAR⁺ Vδ2⁺ T cell functioning as a professional antigen-presenting cell by endocytosis and intracellular processing of L-MART1 protein. Following antigenic stimulation, CellTrace violet-labeled MART1 TCR⁺ αβ T cells proliferate, resulting in dilution of violet dye. (C) Representative histogram showing proliferation as determined by CellTrace violet dilution. (D) Proliferation of responder αβ T cells (MART1 TCR⁺ and MART1 TCR⁻) in multiple donors (horizontal line represents mean value; paired Student’s t test; n = 4). Higher proliferation of Vβ12⁻ cells in S-MART1 conditions is probably due to bystander activation by the Vβ12⁺ responders. The small background proliferation in Vβ12⁺ cells in the absence of peptide is commonly seen following transduction.