Identification of subpopulations of T lymphocytes and Ia positive B lymphocytes using a rosette assay based upon the biotin-avidin interaction.

Bovine erythrocytes were coated with avidin using a chromic chloride coupling technique and used successfully in an indirect rosette assay to identify and quantitate: (a) T-lymphocyte helper and suppressor subpopulations, and (b) Ia positive B-lymphocyte populations. Using mouse monoclonal antibodies to the T-lymphocyte markers OKT3, OKT4, and OKT8 it was shown that the proportion of OKT4 and OKT8 positive cells were respectively 60.9 and 39.2% of the total OKT-3 positive T lymphocytes. In a similar way, using a monoclonal anti-human Ia antibody, the percentage Ia positive cells in B-lymphocyte enriched preparations was shown to vary between 18 and 55% for normal peripheral blood and 31 and 58% for chronic lymphocytic leukaemia derived peripheral blood.