IFNγ PET Imaging as a Predictive Tool for Monitoring Response to Tumor Immunotherapy.

ABSTRACT: IFNγ is an attractive target for imaging active antitumor immunity due to its function in the T-cell signaling axis. Here, we test an IFNγ immuno-PET (immunoPET) probe for its capacity to identify adaptive immunotherapy response after HER2/neu vaccination in both spontaneous salivary and orthotopic neu+ mouse mammary tumors. IFNγ immunoPET detected elevated cytokine levels in situ after vaccination, which inversely correlated with tumor growth rate, an indicator of response to therapy. In a model of induced T-cell anergy where CD8 T cells infiltrate the tumor, but upregulate PD-1, IFNγ tracer uptake was equivalent to isotype control, illustrating a lack of antitumor T-cell activity. The IFNγ immunoPET tracer detected IFNγ protein sequestered on the surface of tumor cells, likely in complex

SUBMITTER: Gibson HM 

PROVIDER: S-EPMC6443251 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature