A group of specialized white blood cells migrates back and forth through lymph nodes to teach other immune cells how to make a greater variety of antibodies against invading bacteria and viruses.

A team led by Michel Nussenzweig at the Rockefeller University in New York City and Gabriel Victora at the Whitehead Institute for Biomedical Research in Cambridge, Massachusetts, used fluorescence microscopy to monitor the behaviour of specialized T cells in lymph nodes in live mice. These T cells guide other white blood cells, known as B cells, to manufacture antibodies. The team found, unexpectedly, that the specialized T cells continually travelled between the structures in which B cells mature. This constant movement exposes stationary B cells to diverse T cells and might result in B cells producing a wider range of pathogen-specific antibodies, the authors say.

Science http://dx.doi.org/10.1126/science.1241680 (2013)