Immunologic memory discovery reported

CAMBRIDGE, England, Feb. 26 (UPI) -- British scientists say they've discovered why people, as they age, develop so-called immunologic memory to newly encountered pathogens.

Kenneth Smith and colleagues at the University of Cambridge found plasma cells, which make antibodies tailored for specific pathogens, express a protein called FcgammaRIIb on their surface, with older plasma cells expressing more of it than newly generated ones.

The study shows when FcgammaRIIb binds onto the older cells it triggers some cells to self destruct, thereby making space for the newly made plasma cells in the bone marrow where they can produce antibodies against recently encountered pathogens.

The authors suggested that plasma cell expression of that protein provides a feedback mechanism to limit the number of antibody-producing cells in the body.

The researchers also demonstrated human myeloma cells, which are a form of cancerous cells arising from plasma cells, are also sensitive to FcgammaRIIb-induced self destruction. Thus, the scientists said, it might be possible to use FcgammaRIIb-targeted therapies to target both pathogenic autoantibody producing cells and myeloma.

The research appeared in last week's issue of the journal Nature Immunology.