Lymph Node Conduits Transport Virions for Rapid T Cell Activation

Despite intense interest in antiviral T cell priming, the routes of virion movement in lymph nodes (LNs) are imperfectly understood. Current models fail to explain how virus-infected cells rapidly appear within the LN interior after viral infection. To better understand virion trafficking in the LN, we determined virion and infected-cell locations after vaccinia and Zika virus administration. Notably, many rapidly infected cells in the LN interior were adjacent to LN conduits. Using confocal and electron microscopy, we clearly visualized virions within conduits. Functionally, CD8(+) T cells rapidly and preferentially associated with vaccinia virus-infected cells deeper in the LN, leading to T cell activation in the LN interior. These results reveal that it is possible for even large virions to flow through LN conduits and infect dendritic cells within the T cell zone to prime CD8(+) T cells.