Properties of Antibodies Cytophilic for Macrophages* by Arthur Berken,$ M.d., and Baruj Benacerraf,§ M.d

The production of an antibody cytophilic for spleen cells in rabbits immunized with human serum albumin was described by Boyden and Sorkin (1, 2, 3) several years ago. These investigators detected the presence of cytophilic antibody by the capacity of the antisera to confer upon normal cells the capability of specifically adsorbing radio-iodinated antigen. Among the deficiencies in such a system is the failure to distinguish from among the heterogeneous population of cells in the tissue suspensions that cell type which is capable of adsorbing the antigen. This deficiency was recently overcome by Boyden (4) who demonstrated in guinea pig anti-sheep red cell serum the presence of an antibody which could selectively bind to homologous peritoneal macrophages and confer upon them the ability to adsorb sheep red cells.