Detection of IL-2 receptor positive tonsillar lymphocytes by monoclonal antibody and protein A coated erythrocytes.

A sensitive rosette method combining staphylococcal protein A coated rabbit red blood cells and the monoclonal antibody anti-Tac was used to search for the presence of interleukin 2 (IL-2) receptor-bearing T lymphocytes in tonsils from patients with chronic tonsillitis. This method revealed the presence of Tac positive T lymphocytes in the tonsils whereas a conventional immunofluorescence technique was unable to do so. To demonstrate that Tac rosette formation resulted in a selective enrichment of IL-2 receptor-bearing T cells, we measured the proliferative response of these cells to exogenous IL-2. The response of Tac rosette positive cells to recombinant IL-2 was always higher than that of the Tac rosette negative or unselected cells, indicating that this rosette method specifically selects T cells expressing IL-2 receptor.