Cellular Immunoadsorbents: a Simplified Technique for Separation of Lymphoid Cell Populations

Abstract

Abstract A simplified and efficient technique for separating T lymphoid cells from non-T cells of mouse, rat and man has been developed. The fractionation procedure is based on the capacity of non-T lymphoid cells to bind antigen-antibody complexes through an Fc receptor. Lymphoid cells are adsorbed on antibody-coated sheep erythrocyte (EA) monolayers prepared in polystyrene Petri dishes previously treated with poly-l-lysine. Adsorption of spleen cells on these monolayers, assisted by a 5-min centrifugation, resulted in 90 to 98% depletion of the Fc receptor-bearing cells (mostly B lymphocytes, but also macrophages and polymorphonuclear leukocytes) in the non-adherent cell population. Eighty to 90% of the adherent cells were capable of forming EA rosettes and could be recovered after lysis of the erythrocytes. The non-adherent fraction comprised at least 90% T-cells. This was determined for mouse and rat spleen cells by lysis with anti-thymocyte serum and complement, and by the absence of immunoglobulin-bearing cells. The specificity of the adsorption was further substantiated by the following observations: 1) lymphoid cells lacking an Fc receptor were not adsorbed; 2) the adsorption to EA monolayers was inhibited by antigen-antibody complexes or by aggregated γ-globulin; and 3) only 10 to 15% of the Fc receptor-bearing cells were attached to non-sensitized erythrocyte (E) monolayers. Fractionation of spleen cells obtained from rats immunized against a syngeneic tumor yielded two separate fractions of cytotoxic lymphoid cells: one (non-adherent, T cells) mediating direct target cell destruction, and the other (adherent, non-T cells) mediating lysis of antibody-coated target cells.