Artificial lymph nodes as good as real ones

Immune responses are initiated in highly organized structures known as lymph nodes, making these structures almost indispensable in the fight against infectious microbes. Previous studies by Watanabe and colleagues have established that structures resembling lymph nodes (artificial lymph nodes; aLNs) can be generated in mice by implanting in them a biocompatible scaffold containing both stromal cells and dendritic cells.

In a study that appears online on March 15 in advance of publication in the April print issue of the Journal of Clinical Investigation Watanabe and colleagues from the RIKEN Institute, Japan, now show that aLNs support the same immune responses as normal lymph nodes. If the mice in which the aLNs were generated had been immunized with a specific protein, the aLNs contained immune cells known as T cells and B cells able to respond to the immunizing protein. Upon transplantation into mice lacking their own T and B cells, the T and B cells in the aLNs responded to further immunization with the specific protein, known as a secondary immune response. Importantly, the cells in the aLNs making this secondary immune response were able to generate memory cells, meaning that the aLN recipients made long-lived responses to the immunizing protein. The authors therefore suggest that aLNs might of therapeutic use in immunodeficient patients.-Journal of Clinical Investigation