A BlySful way to stimulate B cells.

To help fight off infection, the human body depends on antibody-making factories called B cells. In the July 9 SCmNCE, scientists describe a natural human protein, named B lymphocyte stimulator or BlyS, that triggers the proliferation of these crucial factories of the immune system.

Paul A. Moore of Human Genome Sciences in Rockville, Md., and his colleagues found BlyS after sifting through the genes active in immune cells called monocytes. They found that one of the genes encodes a protein that, when given to mice, triggers B cell proliferation and boosts antibody production. Monocytes were known to regulate B cells, but this finding is the first indication of how the two cell types interact.

The investigators predict that BlyS will one day help people with weakened immune systems, such as AIDS patients. Also, since vaccines often depend on stimulating significant antibody production, BlyS might be combined with immunization shots, the scientists suggest. Human Genome Sciences may face a patent battle over BlyS: A group at the University of Lausanne in Switzerland recently reported on a seemingly identical protein that also stimulates B cell proliferation.