Localization of laminin α4 chain in human bone marrow.

Double labeling of bone marrow cryostat sections with antilaminin α4 antiserum (A,C) and the endothelial cell–specific antibody Rb10 (B) or the mAb against α-SM actin (D), respectively, revealed that the laminin α4 chain is mainly found outside the endothelial cells. The colocalization of laminin α4 chain and α-SM muscle actin indicates an expression of laminin α4 in intersinusoidal stromal cells and myoid cells lining sinuses. (Original magnification × 220.)