Examining the presentation of tumor-associated antigens on peptide-pulsed T2 cells

Abstract

Peptide-pulsed T2 cells are routinely used to study T-cell activation by MHC-restricted peptides derived from tumor-associated antigens (TAAs). Nevertheless, the capacity of T2 cells to present antigenic epitopes remains to be precisely quantified, primarily due to the detection limits imposed by available methods. Since naturally-processed TAA-derived epitopes have been shown to be displayed at levels as low as 10–150 copies per cell, highly sensitive detection and quantification techniques are essential to assess the natural degree of T-cell sensitivity. Here, we report the use of soluble, high-affinity T-cell receptors (TCRs) coupled with single-molecule fluorescence microscopy to quantify three reported TAA-derived epitopes on peptide-pulsed T2 cells, dissecting the relationship between concentration of exogenous peptide, number of epitopes presented, and activation of epitope-specific T cells. Our findings indicate that peptide concentrations in the low nanomolar range are required for T2 cells to present TAAs in extents that are comparable to those of malignant cells.

Keywords: :

• antigen presentation
• fluorescence microscopy
• monoclonal TCR
• T2 cells
• T-cell activation
• T-cell receptor
• tumor-associated antigens

Citation: Bossi G, Gerry AB, Paston SJ, Sutton DH, Hassan NJ, Jakobsen BK. Examining the presentation of tumor associated antigens on peptide pulsed T2 cells. OncoImmunology 2013; 2:e26840; 10.4161/onci.26840

Disclosure of Potential Conflicts of Interest

GB, SJP, DHS, NJH and BKJ are employees of Immunocore Ltd. ABG and BKJ are employees of Adaptimmune Ltd.

Acknowledgments

The authors would like to thank all members of the protein engineering group at Immunocore for their invaluable assistance in these studies; and Joanne Oates for assistance in manuscript preparation. Funding was provided by Immunocore Ltd.