RBCs enhance mitogen-driven T lymphocyte proliferation.

PBLs were stimulated in triplicate in 96-well plates with PHA-P (5 μg/mL), PHA-L (5 μg/mL), and OKT3 (0.5 μg/mL) and were cultured for 5 days in the presence or absence of RBCs (RBC:PBL ratio of 100:1). In control cultures, mitogen was omitted. Tritiated thymidine (0.5 μCi/well) was added 4 hours before the end of the culture, cells were harvested on fiber filters, and incorporated thymidine was determined by scintillation counting. Results show thymidine incorporation (cpm, mean ± SD, n = 3) in the different cultures conditions.