imaging the immune tme
Expression of programmed-death ligand 1 (PD-L1) has been shown to correlate with improved response to immunotherapy in human cancers. Currently, testing for PD-L1 expression involves obtaining a biopsy and performing immunohistochemistry. However, biopsy samples may not be representative of the entire tumor and expression of PD-L1 can vary during the course of the disease. In addition, immunohistochemistry procedures and pathologic scoring are error-prone.
Our lab seeks to develop an imaging platform for non-invasive detection and assessment of PD-L1. We utilize radiolabeled PD-L1 to be detected with positron emission tomography. Our goal is to define the parameters that regulate PD-L1 uptake and to factor in non-specific uptake due to intrinsic and radiation-induced vascular permeability of tumors.
By imaging PD-L1 levels, it will be possible to differentiate highly immunogenic tumors from poorly immunogenic tumors which can benefit from radiation as a modality to induce response to anti-PD-L1.