Immune Modulation Therapy and Imaging: Workshop Report

Histocytometry processing and analysis of tissue sections. (1) Fixed tissue section is simultaneously stained with antibodies directed to as many as 14 determinants and imaged in tiled, high-resolution mode using advanced confocal microscope. (2) Image data are deconvoluted to improve signal-to-noise ratio and spatial resolution. (3) Spillover between fluorescent emissions is corrected (compensated). (4–6) The resulting data are used to create cellular objects based on membrane staining, with defined objects retaining all fluorescence information associated with that object. (7) These data are equivalent to flow cytometry data and can be processed using software for flow data analysis, yielding quantitative information about cellular subset frequency (for example) or intensity of staining for a given determinant. (8) Because data also retain spatial x-y-z information about each object, each gated and defined cellular object can also be placed in its original tissue location.

Imaging CD8 T-cell infiltration in tumor immunotherapy. Anti-CD8 PET was performed 5 d after adoptive transfer of OT-1 ovalbumin-specific T cells in C57BL/6 mice bearing subcutaneous Ova-negative and Ova-positive EL4 tumors. Mouse on right was preblocked with cold anti-CD8 antibody.

First-in-human imaging with ⁸⁹Zr-desferrioxamine (Df)-IAb2M anti–prostate-specific membrane antigen minibody in patients with metastatic prostate cancer, compared with ^99mTc-methylene diphosphonate (MDP) bone scan and ¹⁸F-FDG PET maximum-intensity projection (MIP).