DETECTION OF DUFFY ANTIGEN IN THE PLASMA-MEMBRANES AND CAVEOLAE OF VASCULAR ENDOTHELIAL AND EPITHELIAL-CELLS OF NONERYTHROID ORGANS

The nonerythroid expression of the Duffy blood group protein (gp-Fy) w as confined to certain cell types. Immunocytochemistry studies of the kidney showed gp-Fy in the endothelium of glomeruli, peritubular capil laries, vasa recta, and the principal cells (epithelial) of collecting ducts. Gp-Fy was also produced in the endothelial cells of large venu les and epithelial cells (type-I) of pulmonary alveoli. In the thyroid , only the endothelial cells of capillaries produced gp-Fy. In the spl een, the endothelial cells of capillaries, high endothelial venule, an d sinusoids produced abundant gp-Fy. Ultrastructural studies showed th at apical and basolateral plasma membrane domains, including caveolae, had gp-Fy. Immunoblot analysis showed substantially less gp-Fy in non erythroid cells than in erythrocytes. Moreover, the analyzed nonerythr oid organs of Duffy-negative individuals did not produce more gp-Fy to compensate for the lack of this protein in their erythrocytes. The nu cleotide sequence and the size of kidney mRNA from a Duffy-positive in dividual were the same as that of bone marrow. It is assumed, therefor e, that nonerythroid Duffy protein is the product of the same gene as that of bone marrow. This notion is reinforced by the fact that nonery throid and erythroid gp-Fy have the same antigenic domains. (C) 1997 b y The American Society of Hematology.