SHP-1 phosphatase activity counteracts increased T cell receptor affinity
Michael Hebeisen, … , Daniel E. Speiser, Nathalie Rufer
Michael Hebeisen, … , Daniel E. Speiser, Nathalie Rufer
Published February 8, 2013
Citation Information: J Clin Invest. 2013;123(3):1044-1056. https://doi.org/10.1172/JCI65325.
View: Text | PDF
Research Article Immunology

SHP-1 phosphatase activity counteracts increased T cell receptor affinity

Abstract

Anti-self/tumor T cell function can be improved by increasing TCR-peptide MHC (pMHC) affinity within physiological limits, but paradoxically further increases (Kd < 1 μM) lead to drastic functional declines. Using human CD8+ T cells engineered with TCRs of incremental affinity for the tumor antigen HLA-A2/NY-ESO-1, we investigated the molecular mechanisms underlying this high-affinity–associated loss of function. As compared with cells expressing TCR affinities generating optimal function (Kd = 5 to 1 μM), those with supraphysiological affinity (Kd = 1 μM to 15 nM) showed impaired gene expression, signaling, and surface expression of activatory/costimulatory receptors. Preferential expression of the inhibitory receptor programmed cell death-1 (PD-1) was limited to T cells with the highest TCR affinity, correlating with full functional recovery upon PD-1 ligand 1 (PD-L1) blockade. In contrast, upregulation of the Src homology 2 domain-containing phosphatase 1 (SHP-1/PTPN6) was broad, with gradually enhanced expression in CD8+ T cells with increasing TCR affinities. Consequently, pharmacological inhibition of SHP-1 with sodium stibogluconate augmented the function of all engineered T cells, and this correlated with the TCR affinity–dependent levels of SHP-1. These data highlight an unexpected and global role of SHP-1 in regulating CD8+ T cell activation and responsiveness and support the development of therapies inhibiting protein tyrosine phosphatases to enhance T cell–mediated immunity.

Authors

Michael Hebeisen, Lukas Baitsch, Danilo Presotto, Petra Baumgaertner, Pedro Romero, Olivier Michielin, Daniel E. Speiser, Nathalie Rufer

×

Figure 1

Functionality, TCR-αβ surface expression levels, and TCR/CD8 downregulation in CD8+ T cells engineered with self/tumor-specific TCR of incremental affinities.

Options: View larger image (or click on image) Download as PowerPoint
Functionality, TCR-αβ surface expression levels, and TCR/CD8 downregulat...
(A) Ca2+ flux of TCR-transduced CD8+ T cells without (baseline) and with 1 μg/ml HLA-A2/NY-ESO–specific multimer stimulation. Maximal Ca2+ flux after ionomycin stimulation indicates equal capacity to mobilize calcium in all T cell variants. Data are expressed as Indo-1 (violet)/Indo-1 (blue) emission ratio. (B) Cytotoxic activity (% of maximal killing) against Me 275 and Me 290 (HLA-A2+/NY-ESO-1+) and Na8 (HLA-A2+/NY-ESO-1–) tumor cell lines at an effector target ratio of 10:1. (C) Percentage of primary CD8+ T cells expressing the affinity-optimized NY-ESO-1–specific TCRs as detected by A2/NY-ESO-1157–165–specific multimer staining (left panel). Cells with greater than 80% multimer labeling were used for further analysis. Surface expression levels (in MFI) of TCR β-chain BV13.1 (middle panel) and total αβTCR (right panel) are shown for all CD8+ transduced T cells. (D and E) Downregulation of CD8 coreceptor (D; in %) and TCR (E; in MFI) in engineered CD8+ T cells in the absence (baseline) or presence of 0.1 μg/ml unlabeled A2/NY-ESO-1–specific multimer. Data from T cells with reduced CD8 expression (D; CD8 low) are shown as percentage of total T cells (CD8 high and low). TCR downregulation following stimulation (E) is depicted as dark gray histograms or columns. Error bars represent mean ± SD.