Engineering Living Immunotherapeutic Agents for Improved Cancer Treatment

Abstract

Bacteria‐based agents are emerging as promising tools for cancer therapy due to their ability to actively target tumors, trigger localized inflammation, and induce tumor regression. There has been growing interest in using bacteria that are responsive to external cues, such as magnetic fields, to facilitate the formation of robust colonies in tumors and achieve the threshold for clinical efficacy. Several studies have demonstrated the potential of innately magnetically responsive bacteria, known as magnetotactic bacteria (MTB), as steerable agents. However, their immunostimulatory properties, which play a central role in their function as therapeutic agents, have not yet been adequately studied. Here, key aspects of human immune cell response to MTB strain Magnetospirillum magneticum AMB‐1 in physiological environments are characterized. The ability of MTB to maintain magnetic properties, remain viable in whole blood, elicit cytokine production by macrophages, and stimulate uptake of cancer cell material by dendritic cells is examined. This study also investigates the use of MTB–liposome complexes for effective delivery of therapeutic payloads in vitro and explores response to the agent in vivo. Overall, this work establishes the potential of MTB as a versatile, combined delivery platform for immune‐mediated cancer therapy.