Light It Up: A Pre-Clinical Fluorescent Model to Illustrate Immunogenic Cell Death

Abstract

Immunogenic cell death is a recently identified subset of apoptotic cell death that, when activated, may improve outcomes and remission rates in cancer patients. Calreticulin is an essential early-stage damage-associated molecular pattern that is triggered by certain drugs. It is thought that cancer chemotherapeutics and other agents proven to exhibit immunogenic cell death do so by creating endoplasmic reticulum stress that causes calreticulin to translocate to the cell membrane and activate more downstream signals to recruit the immune system. The current gold standard for the detection of immunogenic cell death is a lengthy and costly procedure involving immunocompetent mice vaccinated with cancer cells already exposed to the potentially immunogenic agent. This is not a realistic method to screen all agents for their potential to induce immunogenic cell death (ICD), but the only other pre-clinical models have been done in only one cancer cell line. This study aimed to generate a stable murine head and neck cancer cell line to be used for screening chemotherapeutics using fluorescence, assess the ability of these transfected cells to accurately predict ICD-inducing potential, and test newly modified chemotherapeutics for their potential to cause ICD. To do so, cells were transfected with a plasmid construct for the calreticulin protein and a red-fluorescent protein. The fluorescent model is not a replacement for the gold-standard detection of ICD, but rather enables a more high-throughput approach to the widespread testing of all clinically relevant cancer chemotherapeutics as well as specifically modified chemotherapeutics to induce ICD.