Analyzing the Inflammatory Response Induced by Car-P Macrophages

As a keystone component of our immune system, macrophages monitor our tissues searching for harmful agents, such as cancer cells and pathogens. When a macrophages Fc receptor (FcR) detects IgG, an “eat me” signal, on the target cell, the macrophage activates two parallel response pathways: phagocytosis and inflammation. Phagocytosis is the process in which macrophages engulf target cells. Characteristic of an inflammatory response, macrophages release regulatory proteins that are either toxic to target cells or recruit other immune cells to the target site. One such protein, tumor necrosis factor alpha (TNFa), is released by activated macrophages through the FcR pathway. One way to harness macrophage phagocytosis to fight cancer is to use chimeric antigen receptors for phagocytosis (CAR-Ps). These receptors combine an extracellular domain targeting a protein enriched on cancer cells and the internal signaling domain of the FcR. Previous research shows that CAR-P macrophages can induce phagocytosis. However, the extent of inflammation triggered has not been explored. This study aims to address this gap. Using confocal microscopy, I will measure phagocytic events, TNFa secretion, and active ERK (a kinase required for inflammation) in CAR-P macrophages activated with CD19-coated silica beads. I will compare these results to the extent of inflammation induced by the native FcR pathway activated with IgG-coated silica beads. The results from this study will suggest possible modifications to the CAR-P design to enhance cancer cell targeting and clearance.

Project Mentor: Annalise Bond

Faculty Advisor: Meghan Morrissey