LRRK2 is expressed in B-2 but not in B-1 B cells, and downregulated by cellular activation.

LRRK2, the causal molecule of familial Parkinson's disease, is expressed strongly by one of the B cell subsets, B-2 cells, but not by the other subset, B-1 cells, in the mouse peritoneal cavity, spleen, and peripheral blood. Bone marrow pre-B cells or T cells exhibited little LRRK2 expression. LRRK2 expression was dramatically downregulated upon activation of B-2 cells with various types of stimulation. These results suggest that LRRK2, whose true function has not yet been clarified, may play some important role(s) in the development and function of B cells, particularly the maintenance of B-2 cells in a resting status.