In vivo flow cytometry for monitoring circulating tumor cell clusters and CART cell interactions

Our goal is to exploit endogenous sources of optical contrast, including scattering and endogenous fluorescence and develop an approach that enables us to enumerate cells or cell clusters of interest in flowing blood samples, ultimately in vivo. Georgakoudi was a key member of the team that developed the initial version of this technology while she was at the Massachusetts General Hospital, which relied on the detection of cells expressing fluorescent proteins^{1, 2}. While our initial experiments continued to build on this concept to assess the role of circulating tumor cells in metastasis³, we performed a series of studies to highlight the potential of this approach relying on endogenous scattering ^4-6. More recently, we have shown that machine-learning approaches can truly enable implementation of this technique to identify circulating tumor cell clusters in whole-blood samples flowing through microfluidic devices ^{7, 8}. Our current efforts focus on using this technology to detect interacting CAR-T and B cells to monitor treatment and circulating tumor cell clusters in the blood of patients with metastatic breast cancer.