Immunodissection: use of monoclonal antibodies to isolate specific types of renal cells

Abstract

Several laboratories have described antibodies that are directed against cell surface antigens unique to different renal cell types. It can reasonably be assumed that each different type of renal cell possesses one or more unique antigenic determinants. In principle, it should be possible to prepare monoclonal antibodies against these cell-specific antigens and to use the antibodies as immunoaffinity reagents to isolate populations of specific renal cell types. We employed this approach in one instance to isolate canine cortical collecting tubule (CCT) cells. Approximately 10(7) canine CCT cells can be obtained from 5 g of canine renal cortex. This compares with an estimate of 10(3) to 10(4) CCT cells that can be reasonably obtained by microdissection. The availability of relatively large numbers of cells makes it possible to study in greater detail the cellular physiology and biochemistry of tubule-specific processes such as solute and water transport and hormone action. Our experiences in attempting to isolate canine CCT cells and other renal epithelia have indicated that the ideal monoclonal antibody for immunodissection should 1) interact with only one type of renal cell, 2) be directed against a determinant present in relative abundance, 3) be noncytotoxic, and 4) be an immunoglobulin G. Described in this review are some conceptual and practical aspects of the methods that can be used to develop B lymphocyte-myeloma hybrids producing such ideal monoclonal antibodies and to isolate renal cells using cell-specific monoclonal antibodies.