Isolation and characterization of the sheep erythrocyte receptor in man.

Properties of the sheep erythrocyte receptor on human lymphocytes were examined from two different aspects: inhibition of E-rosette formation by antisera, and extraction of T and non-T cells with 3 M KCl. Antisera to several T cell populations produced significant inhibition of E-rosette formation by human peripheral blood lymphocytes, whereas anti-B cell, anti-beta2-microglobulin, anti-I, and anit-i were ineffective. Sera with activity to HL-A subgroups on the HPBL tested produced complete rosette inhibition, although nonspecific anti-HL-A produced no inhibition. T cell preparations extracted by a 3M KCl technique contained activity that could be bound to SRBC and produce inhibition of rosette formation by HPBL. This inhibitory component could be quickly eluted from the SRBC and retain its inhibitory activity. No inhibitory activity could be demonstrated in extracts of B cells and non-lymphoid cells. These results suggest that 1) T cell-specific and HL-A specific antisera inhibit E-rosette formation; 2) beta2-M is not involved in the SRBC receptor as an active component; and 3) the receptor may be isolated by 3 M KCl extraction, and partially purified by the use of SRBC as a specific immunoadsorbent, without loss of biologic activity.