Monoclonal antibodies to rat renal tissue: an approach to the immunohistological analysis of the nephron-collecting duct system, and ultra-structural localization of antigens.

To obtain more accurate information on the nephron-collecting duct system, monoclonal antibodies against renal tissue were prepared. BALB/c mice were immunized every two weeks with rat renal tissue, either cortex or medulla. Spleen cells were collected and fused with myeloma cells sensitive to hypoxanthine-aminopterin-thymidine medium. Hybrids were selected for production of antibodies by indirect immunofluorescence and cloned by the limiting dilution method. Tissue reactivity of the antibodies obtained was defined by immunofluorescence. The intracellular localization of antigenic determinants was ascertained by immunoelectron microscopy. The antibodies were classified into four major groups: (1) antibodies against proximal tubules; (2) antibodies against distal tubules and the loop of Henle; (3) antibodies against collecting duct system; and (4) antibodies against glomeruli. Using immunoelectron microscopy, various intracellular antigenic determinants were recognized, such as brush border, apical canaliculi, vacuolar apparatus, luminal and basolateral plasma membranes. The results obtained indicated that electron microscopy is indispensable for the immunohistological study of the nephron-collecting duct system. The observations help to understand morphological and functional diversity of the nephron-collecting duct system.