Lymphocyte Subpopulations in Man: Ox Erythrocytes as Indicators in the EA- and EAC-Rosette Tests: Serological and Technical Aspects

Abstract

Serological properties of ox erythrocytes (ORBC) make it possible to select cells which exhibit weak agglutinability despite strong antibody sensitization. This property and the non-binding of unsensitized ORBC to lymphocyte surface membranes make these cells excellently suited as indicators in techniques for the identification of erythrocyte-antibody (EA) and erythrocyte-antibody-complement (EAC) rosette-forming lymphocytes (RFC). The relevant serology for the selection of appropriate cells and antisera is described. Some of the technical aspects of these tests are discussed. A simple method for the sensitization of ORBC with complement is described. The basis for this method is the naturally occurring complement-binding anti-ORBC antibodies of the Ig[immunoglobulin]M class in human sera. After zymosan treatment the sera are deficient in the 5th component of complement and hence non-hemolytic, which makes these sufficient as sensitizing agents in the preparation of EAC indicator cells. The relations of the EA- and EAC-RFC to established T [thymus derived] and B [bone marrow derived] lymphocyte subpopulations are revealed by the enrichment and depletion of lymphocytes rosetting with 2-aminoethylisothiouronium bromide-treated sheep erythrocytes.