Modeling immune responses of cattle to <i>Mycobacterium bovis</i> using magnetic bioprinted granulomas

Mycobacterial infections, including bovine tuberculosis (TB), have a profound impact on global health. This is exemplified by zoonotic TB in humans and animal TB, which is a life-threatening disease in livestock and wildlife. Mycobacteria cause the formation of granulomas, which significantly impact disease progression. Therefore, decoding granulomas is essential for an in-depth understanding of immune responses to mycobacteria. Conventional mouse models frequently fail to develop organized granulomas, and the procurement of samples from granulomatous lesions in cattle and humans is challenging, offering limited insights into the course of infection. Most <i>in vitro</i> TB research is confined to two-dimensional cell cultures, which neglect the spatial characteristics and cellular architecture of granulomas <i>in vivo</i>. To address this gap in knowledge, we have developed a novel multicellular <i>in vitro</i> model for TB. Our spheroid granuloma model, derived from bovine leukocytes using nanotechnologies, offers an adaptable platform for deciphering immune events within granulomas.