Relationship between E receptors and a T-specific surface antigen on human T cells

The aim of this study was the delineation of different antigenic surface determinants on the surface of adult peripheral T cells by means of a specific horse anti-human T-cell serum (ATS). It was shown that this serum reacts both with E receptors and (an) additional T antigen(s). While E receptors showed the already known susceptibility to trypsin, T antigens (as demonstrated in cytotoxicity tests) were resistant to trypsinization even at high concentration. Incubation of the trypsinized peripheral blood lymphocytes (PBL) in 5 per cent CO2 allowed the resynthesis of E-receptors. High concentrations of ATS (without complement) significantly inhibited rosette-formation. This suggests a close steric relationship between E receptors and T antigen(s). However, absorptions of ATS with trypsinized PBL left the E-rosette inhibitory capacity unaltered. Treatment of PBL with ATS in appropriate dilutions and indirect immunofluorescence tests under capping conditions followed by conventional rosette procedures showed that the E receptor and T antigens are separately mobile within the T-cell membrane.