Edelman R, Wheelock E F
Science. 1966 Nov 25;154(3752):1053-5. doi: 10.1126/science.154.3752.1053.
The replication of vesicular stomatitis virus in human leukocyte cultures shows that virus yields can be enhanced 6-to 180-fold by treating the leukocyte cultures with phytohemagglutinin prior to virus inoculation. Data suggest that a substance is produced in phytohemagglutinin-treated leukocyte cultures which is capable, on transfer to fresh leukocytes, of inducing blast cell formation and enhancing virus replication.