Dendritic cells are replenished from blood

 Dendritic cells help direct the body’s immune response by presenting invading antigens to T cells so they know what to attack. But an ongoing debate exists about where dendritic cells originate and how they multiply, especially in the spleen and lymph system. Now, in a paper published in this month’s issue of Nature Immunology, Rockefeller University scientists have come a step closer to understanding the origins of the spleen and lymph node dendritic cells, findings that are especially important for researchers developing immune-cell-targeted vaccines.