Migration Kinetics and Migratory Morphology of Mycobacterium-Infected CD11c-eYFP Murine Bone Marrow Derived Cells

Abstract

Abstract Central nervous system tuberculosis (CNSTB) is the most serious manifestation of extrapulmonary tuberculosis infections that represent 5–10% of all cases. Although migration of mycobacterium infected cells from the lung to the CNS is critical in bacterial dissemination into the CNS, very little is known about the migratory phenotypic changes of mycobacterium infected cells and overall the mechanism of dissemination into the brain is poorly understood. Mycobacterium tuberculosis is an obligate pathogenic bacterial species with it’s only mode of transportation being within innate immune cells. Dendritic cells (DCs) are potent antigen presenting cells that migrate long distances and through interactions with T-cells, initiate the adaptive immune response. Our lab has previously shown DCs are able to leave Mycobacterial granulomatous lesions from the lung with bacteria intact. Here we used live cell imaging of an under-agarose migration assay and cell tracking to define the kinetics of CD11c-eYFP DC migration during Mycobacterial infection. We found that migration of mycobacterium infected cells was impaired towards CCL19 chemokine and infected cells portrayed a migratory morphology distinct from uninfected DCs. With the use of CD11c-eYFP-LifeAct-RFP reporter mice, we characterized actin polymerization dynamics within infected CD11c cells. As actin polymerization plays a central role in cell migration, morphology, and pathogen internalization, to understand this process during mycobacterial infection will lead to novel therapeutic therapies to modulate dissemination into the CNS.