The effect of biotin on the formation of different types of E-rosettes by human lymphocytes

Peripheral blood lymphocytes from healthy human donors were cultured with biotin and concanavalin A (Con A) for varying periods up to 48 h. At the end of incubation, the percentages of total, active, and stable E-rosettes were determined. The percentage of total E-rosettes decreased significantly in the course of time in both cultures with biotin and Con A, but more slowly than in the control cultures. Biotin and Con A induced a significant increase in the number of high-affinity E-rosettes (aE-RFC and sE-RFC). Preincubation for 4 h in the presence of puromycin or actinomycin D inhibited biotin, and Con A stimulated E-rosette formation. These results suggest that the effect of biotin on the T lymphocytes might be due to stimulation of protein synthesis and, perhaps, new receptors for sheep red blood cells (SRBC).