Figure 5 from Breast Cancer Stem Cell–Derived Tumors Escape from γδ T-cell Immunosurveillance In Vivo by Modulating γδ T-cell Ligands

figure

posted on 2023-06-02, 08:41 authored by Katrin Raute, Juliane Strietz, Maria Alejandra Parigiani, Geoffroy Andrieux, Oliver S. Thomas, Klaus M. Kistner, Marina Zintchenko, Peter Aichele, Maike Hofmann, Houjiang Zhou, Wilfried Weber, Melanie Boerries, Mahima Swamy, Jochen Maurer, Susana Minguet

BCSCs phenotypically change in vivo, but still induce γδ T-cell migration. A, The proteomes of BCSC5 culture cells or freshly isolated xenograft-derived tumor cells were analyzed by mass spectrometry. Volcano plot showing differentially expressed proteins. Proteins regulated with P < 0.05 are depicted in red. B, Rowwise Z-score heat maps showing upregulated and downregulated proteins in BCSC5 culture cells or xenograft-derived tumors from two or three biological replicates (BR) as indicated. C, Migration of γδ T cells (CD3⁺γδTCR⁺) in response to BCSC5 culture cells and xenograft-derived tumor cells was determined in a transwell assay. Basal migration towards medium was set to 1.0 and fold changes from three independent experiments using the same 3 healthy donors in each experiment were pooled and analyzed using one-sample Wilcoxon test. D, Migration of Vδ1⁺ (CD3⁺γδTCR⁺Vδ1⁺) and Vδ2⁺(CD3⁺γδTCR⁺Vδ2⁺) T cells in response to BCSC5 culture cells and xenograft-derived tumor cells was determined in a transwell assay. Basal migration toward medium was set to 1.0 and fold changes from three independent experiments using the same 3 healthy donors in each experiment were pooled. One-sample t test (for Vδ1⁺) or one-sample Wilcoxon test (for Vδ2⁺). *, P ≤ 0.05; **, P ≤ 0.01; ****, P ≤ 0.0001. Non-adj., non-adjusted.

Funding

Deutsche Forschungsgemeinschaft (DFG)

KWF Kankerbestrijding (DCS)

History

ARTICLE ABSTRACT

There are no targeted therapies for patients with triple-negative breast cancer (TNBC). TNBC is enriched in breast cancer stem cells (BCSC), which play a key role in metastasis, chemoresistance, relapse, and mortality. γδ T cells hold great potential in immunotherapy against cancer and might provide an approach to therapeutically target TNBC. γδ T cells are commonly observed to infiltrate solid tumors and have an extensive repertoire of tumor-sensing mechanisms, recognizing stress-induced molecules and phosphoantigens (pAgs) on transformed cells. Herein, we show that patient-derived triple-negative BCSCs are efficiently recognized and killed by ex vivo expanded γδ T cells from healthy donors. Orthotopically xenografted BCSCs, however, were refractory to γδ T-cell immunotherapy. We unraveled concerted differentiation and immune escape mechanisms: xenografted BCSCs lost stemness, expression of γδ T-cell ligands, adhesion molecules, and pAgs, thereby evading immune recognition by γδ T cells. Indeed, neither promigratory engineered γδ T cells, nor anti–PD-1 checkpoint blockade, significantly prolonged overall survival of tumor-bearing mice. BCSC immune escape was independent of the immune pressure exerted by the γδ T cells and could be pharmacologically reverted by zoledronate or IFNα treatment. These results pave the way for novel combinatorial immunotherapies for TNBC.