VCOM Research Day Program Book 2023

Medical Student Research Biomedical

20 Adipose-Derived, HER2/neu Tumor-Targeted, Human Mast Cells Have Antitumor Effects In Vivo After Intravenous Injection

Jennelle Norem; Rebecca Praetzel; Mason Conine; Caelin Smith; Benjamin James; Samantha Vicencio; Daniel Courter; Chris Kepley Corresponding author: jnorem@liberty.edu

Liberty University College of Osteopathic Medicine

The use of one's own cells to treat tumors is typified by chimeric antigen receptor T cells (CAR T) therapy. The list of autologous immune cells with anti-tumor properties being investigated continues to grow. We have previously proposed a new strategy using tumor targeted mast cells (MC) obtained from autologous sources and demonstrated proof-of concept previously in vitro and in vivo. We sought to exploit the anti tumor mediators in MC granules to selectively

target them to tumor cells using tumor specific immunoglobin E (IgE) and controllably trigger release of anti-tumor mediators upon tumor cell engagement. We used a human HER2/ neu -specific IgE to arm human MCs through the high affinity IgE receptor (FcεRI). The ability of intravenously (i.v.) injected HER2/ neu -targeted MCs to effect HER2/ neu -positive human tumors was assessed using a immunocompromised xenograft mouse model. It

is shown for the first time that tumor targeted MC injected i.v. home to and shrink tumors. These studies provide further proof of concept that MC have anti-tumor properties and could possibly provide another strategy for developing adoptive cell transfer therapeutics for patients.

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