I study inhibitory receptors that regulate the immune response. Their function ensures the right balance of protective immunity while avoiding self-attack. The prototypical inhibitory receptor is the B-lymphocyte Fc receptor, which provides a feedback inhibition for the production of antibodies.
B cells produce antibodies in response to immune activation of the antigen receptor.
When the antigen is neutralized, the Fc receptor senses the presence of saturating amounts of antibodies and stops B cell activation. Through biochemical and genetic studies using B cell lines, we have analyzed in detail the molecular mechanism of this inhibitory signal, and have shown that it specifically impedes events involved in the influx of calcium from the extracellular medium. I am now studying the relevance of this inhibitory signal by obtaining mice defective in this pathway, or expressing mutant forms of the receptor in transgenic animals.