Abstract
Phytohemagglutinin treatment of peripheral blood leukocytes from dengue nonimmune monkeys enhanced dengue-2 virus replication. Enhancement was due primarily to an increase in the number of infected cells. Destruction of mononuclear phagocytes with silica did not significantly inhibit virus replication in phytohemagglutinin-treated cultures. Pokeweed mitogen, concanavalin A, and streptolysin O stimulated increased deoxyribonucleic acid synthesis in monkey leukocytes but did not enhance virus replication. None of the mitogens significantly affected virus replication in cultures of dengue-immune monkey peripheral blood leukocytes.