Imst-28. Non-invasive Immune Monitoring Following Dc Vaccination Effectively Delineates Immune Responses in Glioblastoma
Year: 2016
Type: conference-abstract
Abstract: Glioblastoma (GBM) is a devastating disease with a median survival of 11-14 months following resection with subsequent standard chemotherapy and radiation. As the immunotherapy field has advanced, immune monitoring of patients receiving these treatments has become especially relevant. In the GBM treatment setting, access to tumor is limited only to instances of surgery for initial needle biopsy or resection. As such, non-invasive immune monitoring is of paramount importance. In this study, we hypothesized that non-invasive D-FAC PET and MRI with contrast could be utilized to provide a measure of immune response in GBM using our murine model. To test this, immunocompetent C57BL/6 mice were implanted with GL261 glioma cells in the brain. Mice were stratified into Control, DC vaccine, and DC vaccine + PD-1 mAb treatment groups and imaged post-treatment using a Bruker 7T MR scanner to obtain anatomical, perfusion, and pH-weighted data. Mice were then administered intravenous [18F]-FAC and dually PET/CT imaged with the Genisys 8 scanner to evaluate the tumor-infiltrating lymphocytic response. Tumor-bearing hemisphere was then harvested, processed, and stained for FACS analysis. There was a significant increase in activated tumor-infiltrating lymphocytes in DC vaccine and DC vaccine + PD-1 mAb-treated mice over control mice on FACS analysis. We then co-registered PET and MRI data to delineate subsets of increased contrast signal with areas of PET-denoted inflammatory response. PET signal intensity was significantly increased in treated mice over control mice that positively correlated with activated lymphocyte infiltration identified on FACS analysis and histology. These findings demonstrate a clinically relevant modality to evaluate immune responses non-invasively following DC vaccine treatment.
Source: Neuro-Oncology
Institution: University of California, Los Angeles
Language: English
Subfield: Genetics (clinical)
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2587627883