Role of the Rap GTPases and the Pyk2 tyrosine kinase in B cell adhesion and spreading

B lymphocytes (B cells), which develop from stem cells in the bone marrow, are specialized immune cells that produce antibodies to fight infections. After developing they move into the blood stream where their role is to detect pathogens and be activated by the encounter to mount an immune response against infectious microbes. An important cellular process called adhesion is involved with the development and activation of B cells. Adhesion is the process whereby receptors on the surface of the B cells bind to receptors on the surface of other cell types. A protein called Rap acts as a molecular switch that cycles between an “on” or “off” state to regulate cell adhesion. Kevin Lin is studying the mechanisms of how Rap regulates B cell adhesion and cytoskeleton remodeling. In particular, he is investigating Rap’s control of the activation and function of Pyk2 (nonreceptor protein tyrosine kinase), believed to be involved in regulating the form and structure of the cell in response to antigen binding and chemokine signaling. This work will provide new insights into processes that regulate the development and activation of B cells, and may be important for a better understanding of inflammatory responses, autoimmune diseases, cancer of B cells, and other immune related diseases.